From patchwork Thu Sep 9 07:11:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Oliva X-Patchwork-Id: 1526110 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org (client-ip=8.43.85.97; helo=sourceware.org; envelope-from=gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org; receiver=) Received: from sourceware.org (server2.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4H4qw75fRzz9t1C for ; Thu, 9 Sep 2021 17:12:53 +1000 (AEST) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id E3CD2384BC22 for ; Thu, 9 Sep 2021 07:12:48 +0000 (GMT) X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from rock.gnat.com (rock.gnat.com [205.232.38.15]) by sourceware.org (Postfix) with ESMTPS id C63AF384C002 for ; Thu, 9 Sep 2021 07:12:03 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org C63AF384C002 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=adacore.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=adacore.com Received: from localhost (localhost.localdomain [127.0.0.1]) by filtered-rock.gnat.com (Postfix) with ESMTP id 7C61B11683C; Thu, 9 Sep 2021 03:12:03 -0400 (EDT) X-Virus-Scanned: Debian amavisd-new at gnat.com X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "Cc" Received: from rock.gnat.com ([127.0.0.1]) by localhost (rock.gnat.com [127.0.0.1]) (amavisd-new, port 10024) with LMTP id 1URkJpVN-iRU; Thu, 9 Sep 2021 03:12:03 -0400 (EDT) Received: from free.home (tron.gnat.com [IPv6:2620:20:4000:0:46a8:42ff:fe0e:e294]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by rock.gnat.com (Postfix) with ESMTPS id CE4C0116404; Thu, 9 Sep 2021 03:12:01 -0400 (EDT) Received: from livre (livre.home [172.31.160.2]) by free.home (8.15.2/8.15.2) with ESMTPS id 1897BiDc2181321 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 9 Sep 2021 04:11:45 -0300 From: Alexandre Oliva To: gcc-patches@gcc.gnu.org Subject: [PATCH] strub: machine-independent stack scrubbing Organization: Free thinker, does not speak for AdaCore References: Date: Thu, 09 Sep 2021 04:11:44 -0300 In-Reply-To: (Alexandre Oliva's message of "Wed, 14 Jul 2021 02:28:43 -0300") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.2 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 X-Spam-Status: No, score=-11.8 required=5.0 tests=BAYES_00, GIT_PATCH_0, KAM_ASCII_DIVIDERS, KAM_DMARC_STATUS, KAM_SHORT, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jan Hubicka , Craig Blackmore , Jim Wilson , Graham Markall Errors-To: gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org Sender: "Gcc-patches" (moving from gcc@ to gcc-patches@) On Jul 14, 2021, Alexandre Oliva wrote: > I've been working on an implementation of stack scrubbing https://gcc.gnu.org/pipermail/gcc/2021-July/236780.html Here's the patch that implements it. introduce stack scrub (strub) feature This patch adds the strub attribute for function and variable types, command-line options, passes and adjustments to implement it, documentation, and tests. Regstrapped on x86_64-linux-gnu. Also successfully bootstrapped with -fstrub=all, along with other patches in branch users/aoliva/heads/strub: https://gcc.gnu.org/pipermail/gcc-patches/2021-July/575040.html https://gcc.gnu.org/pipermail/gcc-patches/2021-July/575043.html https://gcc.gnu.org/pipermail/gcc-patches/2021-July/575044.html Is this ok to install? for gcc/ChangeLog * Makefile.in (OBJS): Add ipa-strub.o. * builtins.def (BUILT_IN_STACK_ADDRESS): New. (BUILT_IN___STRUB_ENTER): New. (BUILT_IN___STRUB_UPDATE): New. (BUILT_IN___STRUB_LEAVE): New. * builtins.c: Include ipa-strub.h. (STACK_STOPS, STACK_UNSIGNED): Define. (expand_builtin_stack_address): New. (expand_builtin_strub_enter): New. (expand_builtin_strub_update): New. (expand_builtin_strub_leave): New. (expand_bulitin): Call them. * common.opt (fstrub=*): New options. * doc/extend.texi (strub): New type attribute. (__builtin_stack_address): New function. (Stack Scrubbing): New section. * doc/invoke.texi (-fstrub=*): New options. (-fdump-ipa-*): New passes. * ipa-inline.c: Include ipa-strub.h. (can_inline_edge_p): Test strub_inlinable_to_p. * ipa-split.c: Include ipa-strub.h. (execute_split_functions): Test strub_splittable_p. * ipa-strub.c, ipa-strub.h: New. * passes.def: Add strub_mode and strub passes. * tree-cfg.c (gimple_verify_flow_info): Note on debug stmts. * tree-pass.h (make_pass_ipa_strub_mode): Declare. (make_pass_ipa_strub): Declare. (make_pass_ipa_function_and_variable_visibility): Fix formatting. * tree-ssa-ccp.c (optimize_stack_restore): Keep restores before strub leave. * multiple_target.c (pass_target_clone::gate): Test seen_error. * attribs.c: Include ipa-strub.h. (decl_attributes): Support applying attributes to function type, rather than pointer type, at handler's request. (comp_type_attributes): Combine strub_comptypes and target comp_type results. for gcc/c-family/ChangeLog * c-attribs.c: Include ipa-strub.h. (handle_strub_attribute): New. (c_common_attribute_table): Add strub. for gcc/ada/ChangeLog * doc/gnat_rm.rst: Add... * doc/gnat_rm/security_hardening_features.rst: New. * doc/gnat_rm/about_this_guide.rst: Link to new chapter. * libgnat/a-except.adb: Make Rcheck_CE_* strub-callable. * libgnat/a-except.ads (Raise_Exception): Likewise. (Raise_Exception_Always): Likewise. * libgnat/s-arit128.ads (Multiply_With_Ovflo_Check128): Likewise. * libgnat/s-arit64.ads (Multiply_With_Ovflo_Check64): Likewise. * libgnat/s-secsta.ads (SS_Allocate, SS_Mark, SS_Release): Likewise. * gcc-interface/trans.c: Include ipa-strub.h. (gigi): Make internal decls for targets of compiler-generated calls strub-callable too. * gcc-interface/utils.c: Include ipa-strub.h. (handle_strub_attribute): New. (gnat_internal_attribute_table): Add strub. for gcc/testsuite/ChangeLog * c-c++-common/strub-O0.c: New. * c-c++-common/strub-O1.c: New. * c-c++-common/strub-O2.c: New. * c-c++-common/strub-O2fni.c: New. * c-c++-common/strub-O3.c: New. * c-c++-common/strub-O3fni.c: New. * c-c++-common/strub-Og.c: New. * c-c++-common/strub-Os.c: New. * c-c++-common/strub-all1.c: New. * c-c++-common/strub-all2.c: New. * c-c++-common/strub-apply1.c: New. * c-c++-common/strub-apply2.c: New. * c-c++-common/strub-apply3.c: New. * c-c++-common/strub-apply4.c: New. * c-c++-common/strub-at-calls1.c: New. * c-c++-common/strub-at-calls2.c: New. * c-c++-common/strub-defer-O1.c: New. * c-c++-common/strub-defer-O2.c: New. * c-c++-common/strub-defer-O3.c: New. * c-c++-common/strub-defer-Os.c: New. * c-c++-common/strub-internal1.c: New. * c-c++-common/strub-internal2.c: New. * c-c++-common/strub-parms1.c: New. * c-c++-common/strub-parms2.c: New. * c-c++-common/strub-parms3.c: New. * c-c++-common/strub-relaxed1.c: New. * c-c++-common/strub-relaxed2.c: New. * c-c++-common/strub-short-O0-exc.c: New. * c-c++-common/strub-short-O0.c: New. * c-c++-common/strub-short-O1.c: New. * c-c++-common/strub-short-O2.c: New. * c-c++-common/strub-short-O3.c: New. * c-c++-common/strub-short-Os.c: New. * c-c++-common/strub-strict1.c: New. * c-c++-common/strub-strict2.c: New. * c-c++-common/strub-tail-O1.c: New. * c-c++-common/strub-tail-O2.c: New. * c-c++-common/torture/strub-callable1.c: New. * c-c++-common/torture/strub-callable2.c: New. * c-c++-common/torture/strub-const1.c: New. * c-c++-common/torture/strub-const2.c: New. * c-c++-common/torture/strub-const3.c: New. * c-c++-common/torture/strub-const4.c: New. * c-c++-common/torture/strub-data1.c: New. * c-c++-common/torture/strub-data2.c: New. * c-c++-common/torture/strub-data3.c: New. * c-c++-common/torture/strub-data4.c: New. * c-c++-common/torture/strub-data5.c: New. * c-c++-common/torture/strub-indcall1.c: New. * c-c++-common/torture/strub-indcall2.c: New. * c-c++-common/torture/strub-indcall3.c: New. * c-c++-common/torture/strub-inlinable1.c: New. * c-c++-common/torture/strub-inlinable2.c: New. * c-c++-common/torture/strub-ptrfn1.c: New. * c-c++-common/torture/strub-ptrfn2.c: New. * c-c++-common/torture/strub-ptrfn3.c: New. * c-c++-common/torture/strub-ptrfn4.c: New. * c-c++-common/torture/strub-pure1.c: New. * c-c++-common/torture/strub-pure2.c: New. * c-c++-common/torture/strub-pure3.c: New. * c-c++-common/torture/strub-pure4.c: New. * c-c++-common/torture/strub-run1.c: New. * c-c++-common/torture/strub-run2.c: New. * c-c++-common/torture/strub-run3.c: New. * c-c++-common/torture/strub-run4.c: New. * c-c++-common/torture/strub-run4c.c: New. * c-c++-common/torture/strub-run4d.c: New. * c-c++-common/torture/strub-run4i.c: New. * g++.dg/strub-run1.C: New. * g++.dg/torture/strub-init1.C: New. * g++.dg/torture/strub-init2.C: New. * g++.dg/torture/strub-init3.C: New. * gnat.dg/strub_attr.adb, gnat.dg/strub_attr.ads: New. * gnat.dg/strub_ind.adb, gnat.dg/strub_ind.ads: New. for libgcc/ChangeLog * Makefile.in (LIB2ADD): Add strub.c. * libgcc2.h (__strub_enter, __strub_update, __strub_leave): Declare. * strub.c: New. --- gcc/Makefile.in | 1 gcc/ada/doc/gnat_rm.rst | 1 gcc/ada/doc/gnat_rm/about_this_guide.rst | 3 .../doc/gnat_rm/security_hardening_features.rst | 88 + gcc/ada/gcc-interface/trans.c | 5 gcc/ada/gcc-interface/utils.c | 67 gcc/ada/libgnat/a-except.adb | 90 + gcc/ada/libgnat/a-except.ads | 8 gcc/ada/libgnat/s-arit128.ads | 6 gcc/ada/libgnat/s-arit64.ads | 6 gcc/ada/libgnat/s-secsta.ads | 10 gcc/attribs.c | 39 gcc/builtins.c | 273 ++ gcc/builtins.def | 4 gcc/c-family/c-attribs.c | 68 gcc/common.opt | 29 gcc/doc/extend.texi | 307 ++ gcc/doc/invoke.texi | 60 gcc/ipa-inline.c | 6 gcc/ipa-split.c | 7 gcc/ipa-strub.c | 3336 ++++++++++++++++++++ gcc/ipa-strub.h | 45 gcc/multiple_target.c | 2 gcc/passes.def | 2 gcc/testsuite/c-c++-common/strub-O0.c | 14 gcc/testsuite/c-c++-common/strub-O1.c | 15 gcc/testsuite/c-c++-common/strub-O2.c | 16 gcc/testsuite/c-c++-common/strub-O2fni.c | 15 gcc/testsuite/c-c++-common/strub-O3.c | 12 gcc/testsuite/c-c++-common/strub-O3fni.c | 15 gcc/testsuite/c-c++-common/strub-Og.c | 16 gcc/testsuite/c-c++-common/strub-Os.c | 18 gcc/testsuite/c-c++-common/strub-all1.c | 32 gcc/testsuite/c-c++-common/strub-all2.c | 24 gcc/testsuite/c-c++-common/strub-apply1.c | 15 gcc/testsuite/c-c++-common/strub-apply2.c | 12 gcc/testsuite/c-c++-common/strub-apply3.c | 8 gcc/testsuite/c-c++-common/strub-apply4.c | 21 gcc/testsuite/c-c++-common/strub-at-calls1.c | 30 gcc/testsuite/c-c++-common/strub-at-calls2.c | 23 gcc/testsuite/c-c++-common/strub-defer-O1.c | 7 gcc/testsuite/c-c++-common/strub-defer-O2.c | 8 gcc/testsuite/c-c++-common/strub-defer-O3.c | 93 + gcc/testsuite/c-c++-common/strub-defer-Os.c | 7 gcc/testsuite/c-c++-common/strub-internal1.c | 31 gcc/testsuite/c-c++-common/strub-internal2.c | 21 gcc/testsuite/c-c++-common/strub-parms1.c | 48 gcc/testsuite/c-c++-common/strub-parms2.c | 36 gcc/testsuite/c-c++-common/strub-parms3.c | 58 gcc/testsuite/c-c++-common/strub-relaxed1.c | 18 gcc/testsuite/c-c++-common/strub-relaxed2.c | 14 gcc/testsuite/c-c++-common/strub-short-O0-exc.c | 10 gcc/testsuite/c-c++-common/strub-short-O0.c | 10 gcc/testsuite/c-c++-common/strub-short-O1.c | 10 gcc/testsuite/c-c++-common/strub-short-O2.c | 10 gcc/testsuite/c-c++-common/strub-short-O3.c | 12 gcc/testsuite/c-c++-common/strub-short-Os.c | 12 gcc/testsuite/c-c++-common/strub-strict1.c | 36 gcc/testsuite/c-c++-common/strub-strict2.c | 25 gcc/testsuite/c-c++-common/strub-tail-O1.c | 8 gcc/testsuite/c-c++-common/strub-tail-O2.c | 14 .../c-c++-common/torture/strub-callable1.c | 9 .../c-c++-common/torture/strub-callable2.c | 264 ++ gcc/testsuite/c-c++-common/torture/strub-const1.c | 18 gcc/testsuite/c-c++-common/torture/strub-const2.c | 22 gcc/testsuite/c-c++-common/torture/strub-const3.c | 13 gcc/testsuite/c-c++-common/torture/strub-const4.c | 17 gcc/testsuite/c-c++-common/torture/strub-data1.c | 13 gcc/testsuite/c-c++-common/torture/strub-data2.c | 14 gcc/testsuite/c-c++-common/torture/strub-data3.c | 14 gcc/testsuite/c-c++-common/torture/strub-data4.c | 14 gcc/testsuite/c-c++-common/torture/strub-data5.c | 15 .../c-c++-common/torture/strub-indcall1.c | 14 .../c-c++-common/torture/strub-indcall2.c | 14 .../c-c++-common/torture/strub-indcall3.c | 14 .../c-c++-common/torture/strub-inlinable1.c | 16 .../c-c++-common/torture/strub-inlinable2.c | 7 gcc/testsuite/c-c++-common/torture/strub-ptrfn1.c | 10 gcc/testsuite/c-c++-common/torture/strub-ptrfn2.c | 55 gcc/testsuite/c-c++-common/torture/strub-ptrfn3.c | 50 gcc/testsuite/c-c++-common/torture/strub-ptrfn4.c | 43 gcc/testsuite/c-c++-common/torture/strub-pure1.c | 18 gcc/testsuite/c-c++-common/torture/strub-pure2.c | 22 gcc/testsuite/c-c++-common/torture/strub-pure3.c | 13 gcc/testsuite/c-c++-common/torture/strub-pure4.c | 17 gcc/testsuite/c-c++-common/torture/strub-run1.c | 85 + gcc/testsuite/c-c++-common/torture/strub-run2.c | 75 gcc/testsuite/c-c++-common/torture/strub-run3.c | 75 gcc/testsuite/c-c++-common/torture/strub-run4.c | 101 + gcc/testsuite/c-c++-common/torture/strub-run4c.c | 5 gcc/testsuite/c-c++-common/torture/strub-run4d.c | 7 gcc/testsuite/c-c++-common/torture/strub-run4i.c | 5 gcc/testsuite/g++.dg/strub-run1.C | 19 gcc/testsuite/g++.dg/torture/strub-init1.C | 13 gcc/testsuite/g++.dg/torture/strub-init2.C | 14 gcc/testsuite/g++.dg/torture/strub-init3.C | 13 gcc/testsuite/gnat.dg/strub_attr.adb | 37 gcc/testsuite/gnat.dg/strub_attr.ads | 12 gcc/testsuite/gnat.dg/strub_ind.adb | 44 gcc/testsuite/gnat.dg/strub_ind.ads | 23 gcc/tree-cfg.c | 1 gcc/tree-pass.h | 5 gcc/tree-ssa-ccp.c | 4 libgcc/Makefile.in | 2 libgcc/libgcc2.h | 4 libgcc/strub.c | 112 + 106 files changed, 6588 insertions(+), 11 deletions(-) create mode 100644 gcc/ada/doc/gnat_rm/security_hardening_features.rst create mode 100644 gcc/ipa-strub.c create mode 100644 gcc/ipa-strub.h create mode 100644 gcc/testsuite/c-c++-common/strub-O0.c create mode 100644 gcc/testsuite/c-c++-common/strub-O1.c create mode 100644 gcc/testsuite/c-c++-common/strub-O2.c create mode 100644 gcc/testsuite/c-c++-common/strub-O2fni.c create mode 100644 gcc/testsuite/c-c++-common/strub-O3.c create mode 100644 gcc/testsuite/c-c++-common/strub-O3fni.c create mode 100644 gcc/testsuite/c-c++-common/strub-Og.c create mode 100644 gcc/testsuite/c-c++-common/strub-Os.c create mode 100644 gcc/testsuite/c-c++-common/strub-all1.c create mode 100644 gcc/testsuite/c-c++-common/strub-all2.c create mode 100644 gcc/testsuite/c-c++-common/strub-apply1.c create mode 100644 gcc/testsuite/c-c++-common/strub-apply2.c create mode 100644 gcc/testsuite/c-c++-common/strub-apply3.c create mode 100644 gcc/testsuite/c-c++-common/strub-apply4.c create mode 100644 gcc/testsuite/c-c++-common/strub-at-calls1.c create mode 100644 gcc/testsuite/c-c++-common/strub-at-calls2.c create mode 100644 gcc/testsuite/c-c++-common/strub-defer-O1.c create mode 100644 gcc/testsuite/c-c++-common/strub-defer-O2.c create mode 100644 gcc/testsuite/c-c++-common/strub-defer-O3.c create mode 100644 gcc/testsuite/c-c++-common/strub-defer-Os.c create mode 100644 gcc/testsuite/c-c++-common/strub-internal1.c create mode 100644 gcc/testsuite/c-c++-common/strub-internal2.c create mode 100644 gcc/testsuite/c-c++-common/strub-parms1.c create mode 100644 gcc/testsuite/c-c++-common/strub-parms2.c create mode 100644 gcc/testsuite/c-c++-common/strub-parms3.c create mode 100644 gcc/testsuite/c-c++-common/strub-relaxed1.c create mode 100644 gcc/testsuite/c-c++-common/strub-relaxed2.c create mode 100644 gcc/testsuite/c-c++-common/strub-short-O0-exc.c create mode 100644 gcc/testsuite/c-c++-common/strub-short-O0.c create mode 100644 gcc/testsuite/c-c++-common/strub-short-O1.c create mode 100644 gcc/testsuite/c-c++-common/strub-short-O2.c create mode 100644 gcc/testsuite/c-c++-common/strub-short-O3.c create mode 100644 gcc/testsuite/c-c++-common/strub-short-Os.c create mode 100644 gcc/testsuite/c-c++-common/strub-strict1.c create mode 100644 gcc/testsuite/c-c++-common/strub-strict2.c create mode 100644 gcc/testsuite/c-c++-common/strub-tail-O1.c create mode 100644 gcc/testsuite/c-c++-common/strub-tail-O2.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-callable1.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-callable2.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-const1.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-const2.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-const3.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-const4.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-data1.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-data2.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-data3.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-data4.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-data5.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-indcall1.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-indcall2.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-indcall3.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-inlinable1.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-inlinable2.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-ptrfn1.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-ptrfn2.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-ptrfn3.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-ptrfn4.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-pure1.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-pure2.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-pure3.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-pure4.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-run1.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-run2.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-run3.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-run4.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-run4c.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-run4d.c create mode 100644 gcc/testsuite/c-c++-common/torture/strub-run4i.c create mode 100644 gcc/testsuite/g++.dg/strub-run1.C create mode 100644 gcc/testsuite/g++.dg/torture/strub-init1.C create mode 100644 gcc/testsuite/g++.dg/torture/strub-init2.C create mode 100644 gcc/testsuite/g++.dg/torture/strub-init3.C create mode 100644 gcc/testsuite/gnat.dg/strub_attr.adb create mode 100644 gcc/testsuite/gnat.dg/strub_attr.ads create mode 100644 gcc/testsuite/gnat.dg/strub_ind.adb create mode 100644 gcc/testsuite/gnat.dg/strub_ind.ads create mode 100644 libgcc/strub.c diff --git a/gcc/Makefile.in b/gcc/Makefile.in index f0c560fe45b77..b60bf8f3d3e64 100644 --- a/gcc/Makefile.in +++ b/gcc/Makefile.in @@ -1472,6 +1472,7 @@ OBJS = \ ipa-reference.o \ ipa-ref.o \ ipa-utils.o \ + ipa-strub.o \ ipa.o \ ira.o \ ira-build.o \ diff --git a/gcc/ada/doc/gnat_rm.rst b/gcc/ada/doc/gnat_rm.rst index 97f7e4d457036..7743ef8b5f437 100644 --- a/gcc/ada/doc/gnat_rm.rst +++ b/gcc/ada/doc/gnat_rm.rst @@ -55,6 +55,7 @@ GNAT Reference Manual gnat_rm/specialized_needs_annexes gnat_rm/implementation_of_specific_ada_features gnat_rm/implementation_of_ada_2012_features + gnat_rm/security_hardening_features gnat_rm/obsolescent_features gnat_rm/compatibility_and_porting_guide diff --git a/gcc/ada/doc/gnat_rm/about_this_guide.rst b/gcc/ada/doc/gnat_rm/about_this_guide.rst index b48785eeed0e9..9defee818aca3 100644 --- a/gcc/ada/doc/gnat_rm/about_this_guide.rst +++ b/gcc/ada/doc/gnat_rm/about_this_guide.rst @@ -96,6 +96,9 @@ This reference manual contains the following chapters: * :ref:`Implementation_of_Ada_2012_Features`, describes the status of the GNAT implementation of the Ada 2012 language standard. +* :ref:`Security_Hardening_Features` documents GNAT extensions aimed + at security hardening. + * :ref:`Obsolescent_Features` documents implementation dependent features, including pragmas and attributes, which are considered obsolescent, since there are other preferred ways of achieving the same results. These diff --git a/gcc/ada/doc/gnat_rm/security_hardening_features.rst b/gcc/ada/doc/gnat_rm/security_hardening_features.rst new file mode 100644 index 0000000000000..753452904128e --- /dev/null +++ b/gcc/ada/doc/gnat_rm/security_hardening_features.rst @@ -0,0 +1,88 @@ +.. _Security_Hardening_Features: + +*************************** +Security Hardening Features +*************************** + +This chapter describes Ada extensions aimed at security hardening that +are provided by GNAT. + +.. Register Scrubbing: + +Register Scrubbing +================== + +GNAT can generate code to zero-out hardware registers before returning +from a subprogram. + +It can be enabled with the *-fzero-call-used-regs* command line +option, to affect all subprograms in a compilation, and with a +:samp:`Machine_Attribute` pragma, to affect only specific subprograms. + +.. code-block:: ada + + procedure Foo; + pragma Machine_Attribute (Foo, "zero_call_used_regs", "used"); + -- Before returning, Foo scrubs only call-clobbered registers + -- that it uses itself. + + function Bar return Integer; + pragma Machine_Attribute (Bar, "zero_call_used_regs", "all"); + -- Before returning, Bar scrubs all call-clobbered registers. + + +For usage and more details on the command line option, and on the +``zero_call_used_regs`` attribute, see :title:`Using the GNU Compiler +Collection (GCC)`. + + +.. Stack Scrubbing: + +Stack Scrubbing +=============== + +GNAT can generate code to zero-out stack frames used by subprograms. + +It can be activated with the :samp:`Machine_Attribute` pragma, on +specific subprograms, variables, and types. + +.. code-block:: ada + + function Foo returns Integer; + pragma Machine_Attribute (Foo, "strub"); + -- Foo and its callers are modified so as to scrub the stack + -- space used by Foo after it returns. + + procedure Bar; + pragma Machine_Attribute (Bar, "strub", "internal"); + -- Bar is turned into a wrapper for its original body, + -- and they scrub the stack used by the original body. + + Var : Integer; + pragma Machine_Attribute (Var, "strub"); + -- Reading from Var in a subprogram enables stack scrubbing + -- of the stack space used by the subprogram. + + +There are also *-fstrub* command line options to control default +settings. For usage and more details on the command line option, and +on the ``strub`` attribute, see :title:`Using the GNU Compiler +Collection (GCC)`. + +Note that Ada secondary stacks are not scrubbed. The restriction +``No_Secondary_Stack`` avoids their use, and thus their accidental +preservation of data that should be scrubbed. + +Also note that the machine attribute is not integrated in the Ada type +system. Though it may modify subprogram and variable interfaces, it +is not fully reflected in Ada types, ``Access`` attributes, renaming +and overriding. Every access type, renaming, and overriding and +overridden dispatching operations that may refer to an entity with an +attribute-modified interface must be annotated with the same +interface-modifying attribute, or with an interface-compatible one. + +Even then, applying the pragma to anything other than subprograms and +scalar variables is not currently supported, and may be silently +ignored. Specifically, it is not recommended to rely on any effects +of this pragma on access types and objects to data variables and to +subprograms. diff --git a/gcc/ada/gcc-interface/trans.c b/gcc/ada/gcc-interface/trans.c index 3df56aa0560e1..f1524a3fb906c 100644 --- a/gcc/ada/gcc-interface/trans.c +++ b/gcc/ada/gcc-interface/trans.c @@ -43,6 +43,7 @@ #include "output.h" #include "debug.h" #include "libfuncs.h" /* For set_stack_check_libfunc. */ +#include "ipa-strub.h" /* For strub_make_callable. */ #include "tree-iterator.h" #include "gimplify.h" #include "opts.h" @@ -444,6 +445,7 @@ gigi (Node_Id gnat_root, int64_type, NULL_TREE), NULL_TREE, is_default, true, true, true, false, false, NULL, Empty); + strub_make_callable (mulv64_decl); if (Enable_128bit_Types) { @@ -456,6 +458,7 @@ gigi (Node_Id gnat_root, NULL_TREE), NULL_TREE, is_default, true, true, true, false, false, NULL, Empty); + strub_make_callable (mulv128_decl); } /* Name of the _Parent field in tagged record types. */ @@ -531,6 +534,7 @@ gigi (Node_Id gnat_root, = create_subprog_decl (get_identifier ("__gnat_raise_nodefer_with_msg"), NULL_TREE, ftype, NULL_TREE, is_default, true, true, true, false, false, NULL, Empty); + strub_make_callable (raise_nodefer_decl); set_exception_parameter_decl = create_subprog_decl @@ -779,6 +783,7 @@ build_raise_check (int check, enum exception_info_kind kind) = create_subprog_decl (get_identifier (Name_Buffer), NULL_TREE, ftype, NULL_TREE, is_default, true, true, true, false, false, NULL, Empty); + strub_make_callable (result); return result; } diff --git a/gcc/ada/gcc-interface/utils.c b/gcc/ada/gcc-interface/utils.c index f85373e2f76ef..193772cc82970 100644 --- a/gcc/ada/gcc-interface/utils.c +++ b/gcc/ada/gcc-interface/utils.c @@ -39,6 +39,7 @@ #include "varasm.h" #include "toplev.h" #include "opts.h" +#include "ipa-strub.h" #include "output.h" #include "debug.h" #include "convert.h" @@ -94,6 +95,7 @@ static tree handle_sentinel_attribute (tree *, tree, tree, int, bool *); static tree handle_noreturn_attribute (tree *, tree, tree, int, bool *); static tree handle_stack_protect_attribute (tree *, tree, tree, int, bool *); static tree handle_no_stack_protector_attribute (tree *, tree, tree, int, bool *); +static tree handle_strub_attribute (tree *, tree, tree, int, bool *); static tree handle_noinline_attribute (tree *, tree, tree, int, bool *); static tree handle_noclone_attribute (tree *, tree, tree, int, bool *); static tree handle_noicf_attribute (tree *, tree, tree, int, bool *); @@ -157,6 +159,8 @@ const struct attribute_spec gnat_internal_attribute_table[] = { "no_stack_protector",0, 0, true, false, false, false, handle_no_stack_protector_attribute, attr_stack_protect_exclusions }, + { "strub", 0, 1, false, true, false, true, + handle_strub_attribute, NULL }, { "noinline", 0, 0, true, false, false, false, handle_noinline_attribute, NULL }, { "noclone", 0, 0, true, false, false, false, @@ -6599,6 +6603,69 @@ handle_no_stack_protector_attribute (tree *node, tree name, tree, int, return NULL_TREE; } +/* Handle a "strub" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_strub_attribute (tree *node, tree name, + tree args, + int ARG_UNUSED (flags), bool *no_add_attrs) +{ + bool enable = true; + + if (args + && POINTER_TYPE_P (*node) + && FUNC_OR_METHOD_TYPE_P (TREE_TYPE (*node))) + *node = TREE_TYPE (*node); + + if (args && FUNC_OR_METHOD_TYPE_P (*node)) + { + switch (strub_validate_fn_attr_parm (TREE_VALUE (args))) + { + case 1: + case 2: + enable = true; + break; + + case 0: + warning (OPT_Wattributes, + "%qE attribute ignored because of argument %qE", + name, TREE_VALUE (args)); + *no_add_attrs = true; + enable = false; + break; + + case -1: + case -2: + enable = false; + break; + + default: + gcc_unreachable (); + } + + args = TREE_CHAIN (args); + } + + if (args) + { + warning (OPT_Wattributes, + "ignoring attribute %qE because of excess arguments" + " starting at %qE", + name, TREE_VALUE (args)); + *no_add_attrs = true; + enable = false; + } + + /* If we see a strub-enabling attribute, and we're at the default setting, + implicitly or explicitly, note that the attribute was seen, so that we can + reduce the compile-time overhead to nearly zero when the strub feature is + not used. */ + if (enable && flag_strub < -2) + flag_strub += 2; + + return NULL_TREE; +} /* Handle a "noinline" attribute; arguments as in struct attribute_spec.handler. */ diff --git a/gcc/ada/libgnat/a-except.adb b/gcc/ada/libgnat/a-except.adb index c332afad0f8a1..593392809d92d 100644 --- a/gcc/ada/libgnat/a-except.adb +++ b/gcc/ada/libgnat/a-except.adb @@ -629,6 +629,96 @@ package body Ada.Exceptions is pragma No_Return (Rcheck_CE_Invalid_Data_Ext); pragma No_Return (Rcheck_CE_Range_Check_Ext); + -- Make all of these procedures callable from strub contexts. + -- These attributes are not visible to callers; they are made + -- visible in trans.c:build_raise_check. + + pragma Machine_Attribute (Rcheck_CE_Access_Check, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_CE_Null_Access_Parameter, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_CE_Discriminant_Check, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_CE_Divide_By_Zero, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_CE_Explicit_Raise, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_CE_Index_Check, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_CE_Invalid_Data, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_CE_Length_Check, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_CE_Null_Exception_Id, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_CE_Null_Not_Allowed, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_CE_Overflow_Check, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_CE_Partition_Check, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_CE_Range_Check, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_CE_Tag_Check, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_PE_Access_Before_Elaboration, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_PE_Accessibility_Check, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_PE_Address_Of_Intrinsic, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_PE_Aliased_Parameters, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_PE_All_Guards_Closed, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_PE_Bad_Predicated_Generic_Type, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_PE_Build_In_Place_Mismatch, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_PE_Current_Task_In_Entry_Body, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_PE_Duplicated_Entry_Address, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_PE_Explicit_Raise, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_PE_Implicit_Return, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_PE_Misaligned_Address_Value, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_PE_Missing_Return, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_PE_Non_Transportable_Actual, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_PE_Overlaid_Controlled_Object, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_PE_Potentially_Blocking_Operation, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_PE_Stream_Operation_Not_Allowed, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_PE_Stubbed_Subprogram_Called, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_PE_Unchecked_Union_Restriction, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_PE_Finalize_Raised_Exception, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_SE_Empty_Storage_Pool, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_SE_Explicit_Raise, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_SE_Infinite_Recursion, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_SE_Object_Too_Large, + "strub", "callable"); + + pragma Machine_Attribute (Rcheck_CE_Access_Check_Ext, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_CE_Index_Check_Ext, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_CE_Invalid_Data_Ext, + "strub", "callable"); + pragma Machine_Attribute (Rcheck_CE_Range_Check_Ext, + "strub", "callable"); + --------------------------------------------- -- Reason Strings for Run-Time Check Calls -- --------------------------------------------- diff --git a/gcc/ada/libgnat/a-except.ads b/gcc/ada/libgnat/a-except.ads index 2b27adb6ca1b8..b5a2e48f96aae 100644 --- a/gcc/ada/libgnat/a-except.ads +++ b/gcc/ada/libgnat/a-except.ads @@ -81,6 +81,10 @@ package Ada.Exceptions is pragma No_Return (Raise_Exception); -- Note: In accordance with AI-466, CE is raised if E = Null_Id + -- Make it callable from strub contexts. + pragma Machine_Attribute (Raise_Exception, + "strub", "callable"); + function Exception_Message (X : Exception_Occurrence) return String; procedure Reraise_Occurrence (X : Exception_Occurrence); @@ -184,6 +188,10 @@ private -- Raise_Exception_Always if it can determine this is the case. The Export -- allows this routine to be accessed from Pure units. + -- Make it callable from strub contexts. + pragma Machine_Attribute (Raise_Exception_Always, + "strub", "callable"); + procedure Raise_From_Controlled_Operation (X : Exception_Occurrence); pragma No_Return (Raise_From_Controlled_Operation); pragma Export diff --git a/gcc/ada/libgnat/s-arit128.ads b/gcc/ada/libgnat/s-arit128.ads index 6213cfb569a24..5d3fff6d8e14f 100644 --- a/gcc/ada/libgnat/s-arit128.ads +++ b/gcc/ada/libgnat/s-arit128.ads @@ -57,6 +57,12 @@ package System.Arith_128 is -- bits, otherwise returns the 128-bit signed integer product. -- Gigi may also call this routine directly. + -- Make it callable from strub contexts. + -- There is a matching setting in trans.c, + -- for calls issued by Gigi. + pragma Machine_Attribute (Multiply_With_Ovflo_Check128, + "strub", "callable"); + procedure Scaled_Divide128 (X, Y, Z : Int128; Q, R : out Int128; diff --git a/gcc/ada/libgnat/s-arit64.ads b/gcc/ada/libgnat/s-arit64.ads index c9141f5fe3e89..170c2bdf1de93 100644 --- a/gcc/ada/libgnat/s-arit64.ads +++ b/gcc/ada/libgnat/s-arit64.ads @@ -57,6 +57,12 @@ package System.Arith_64 is -- bits, otherwise returns the 64-bit signed integer product. -- Gigi may also call this routine directly. + -- Make it callable from strub contexts. + -- There is a matching setting in trans.c, + -- for calls issued by Gigi. + pragma Machine_Attribute (Multiply_With_Ovflo_Check64, + "strub", "callable"); + procedure Scaled_Divide64 (X, Y, Z : Int64; Q, R : out Int64; diff --git a/gcc/ada/libgnat/s-secsta.ads b/gcc/ada/libgnat/s-secsta.ads index 7d6b1b9a90eb0..63df82c8392e4 100644 --- a/gcc/ada/libgnat/s-secsta.ads +++ b/gcc/ada/libgnat/s-secsta.ads @@ -85,6 +85,9 @@ package System.Secondary_Stack is -- -- * Create a new chunk that fits the requested Storage_Size. + pragma Machine_Attribute (SS_Allocate, "strub", "callable"); + -- Enable it to be called from within strub contexts. + procedure SS_Free (Stack : in out SS_Stack_Ptr); -- Free all dynamic chunks of secondary stack Stack. If possible, free the -- stack itself. @@ -92,9 +95,16 @@ package System.Secondary_Stack is function SS_Mark return Mark_Id; -- Capture and return the state of the invoking task's secondary stack + pragma Machine_Attribute (SS_Mark, "strub", "callable"); + -- Enable it to be called from within strub contexts. + procedure SS_Release (M : Mark_Id); -- Restore the state of the invoking task's secondary stack to mark M + pragma Machine_Attribute (SS_Release, "strub", "callable"); + -- Enable it to be called from within strub contexts. + -- FIXME: should there be a scrubbing SS_Release? + function SS_Get_Max return Long_Long_Integer; -- Return the high water mark of the invoking task's secondary stack, in -- bytes. diff --git a/gcc/attribs.c b/gcc/attribs.c index 0d22c20a35e16..07f81285d7a2d 100644 --- a/gcc/attribs.c +++ b/gcc/attribs.c @@ -27,6 +27,7 @@ along with GCC; see the file COPYING3. If not see #include "diagnostic-core.h" #include "attribs.h" #include "fold-const.h" +#include "ipa-strub.h" #include "stor-layout.h" #include "langhooks.h" #include "plugin.h" @@ -617,12 +618,11 @@ decl_attributes (tree *node, tree attributes, int flags, flags &= ~(int) ATTR_FLAG_TYPE_IN_PLACE; } - if (spec->function_type_required && TREE_CODE (*anode) != FUNCTION_TYPE - && TREE_CODE (*anode) != METHOD_TYPE) + if (spec->function_type_required + && !FUNC_OR_METHOD_TYPE_P (*anode)) { if (TREE_CODE (*anode) == POINTER_TYPE - && (TREE_CODE (TREE_TYPE (*anode)) == FUNCTION_TYPE - || TREE_CODE (TREE_TYPE (*anode)) == METHOD_TYPE)) + && FUNC_OR_METHOD_TYPE_P (TREE_TYPE (*anode))) { /* OK, this is a bit convoluted. We can't just make a copy of the pointer type and modify its TREE_TYPE, because if @@ -715,7 +715,23 @@ decl_attributes (tree *node, tree attributes, int flags, tree ret = (spec->handler) (cur_and_last_decl, name, args, flags|cxx11_flag, &no_add_attrs); - *anode = cur_and_last_decl[0]; + if (*anode != cur_and_last_decl[0]) + { + /* Even if !spec->function_type_required, allow the attribute + handler to request the attribute to be applied to the function + type, rather than to the function pointer type, by setting + cur_and_last_decl[0] to the function type. */ + if (!fn_ptr_tmp + && POINTER_TYPE_P (*anode) + && TREE_TYPE (*anode) == cur_and_last_decl[0] + && FUNC_OR_METHOD_TYPE_P (TREE_TYPE (*anode))) + { + fn_ptr_tmp = TREE_TYPE (*anode); + fn_ptr_quals = TYPE_QUALS (*anode); + anode = &fn_ptr_tmp; + } + *anode = cur_and_last_decl[0]; + } if (ret == error_mark_node) { warning (OPT_Wattributes, "%qE attribute ignored", name); @@ -1353,9 +1369,20 @@ comp_type_attributes (const_tree type1, const_tree type2) if ((lookup_attribute ("nocf_check", TYPE_ATTRIBUTES (type1)) != NULL) ^ (lookup_attribute ("nocf_check", TYPE_ATTRIBUTES (type2)) != NULL)) return 0; + int strub_ret = strub_comptypes (CONST_CAST_TREE (type1), + CONST_CAST_TREE (type2)); + if (strub_ret == 0) + return strub_ret; /* As some type combinations - like default calling-convention - might be compatible, we have to call the target hook to get the final result. */ - return targetm.comp_type_attributes (type1, type2); + int target_ret = targetm.comp_type_attributes (type1, type2); + if (target_ret == 0) + return target_ret; + if (strub_ret == 2 || target_ret == 2) + return 2; + if (strub_ret == 1 && target_ret == 1) + return 1; + gcc_unreachable (); } /* PREDICATE acts as a function of type: diff --git a/gcc/builtins.c b/gcc/builtins.c index 9954862776125..7ad91ea6f7a3e 100644 --- a/gcc/builtins.c +++ b/gcc/builtins.c @@ -70,6 +70,7 @@ along with GCC; see the file COPYING3. If not see #include "gimple-fold.h" #include "intl.h" #include "file-prefix-map.h" /* remap_macro_filename() */ +#include "ipa-strub.h" /* strub_watermark_parm() */ #include "gomp-constants.h" #include "omp-general.h" #include "tree-dfa.h" @@ -150,6 +151,7 @@ static rtx expand_builtin_strnlen (tree, rtx, machine_mode); static rtx expand_builtin_alloca (tree); static rtx expand_builtin_unop (machine_mode, tree, rtx, rtx, optab); static rtx expand_builtin_frame_address (tree, tree); +static rtx expand_builtin_stack_address (); static tree stabilize_va_list_loc (location_t, tree, int); static rtx expand_builtin_expect (tree, rtx); static rtx expand_builtin_expect_with_probability (tree, rtx); @@ -4871,6 +4873,256 @@ expand_builtin_frame_address (tree fndecl, tree exp) } } +#ifndef STACK_GROWS_DOWNWARD +# define STACK_TOPS GT +#else +# define STACK_TOPS LT +#endif + +#ifdef POINTERS_EXTEND_UNSIGNED +# define STACK_UNSIGNED POINTERS_EXTEND_UNSIGNED +#else +# define STACK_UNSIGNED true +#endif + +/* Expand a call to builtin function __builtin_stack_address. */ + +static rtx +expand_builtin_stack_address () +{ + return convert_to_mode (ptr_mode, copy_to_reg (stack_pointer_rtx), + STACK_UNSIGNED); +} + +/* Expand a call to builtin function __builtin_strub_enter. */ + +static rtx +expand_builtin_strub_enter (tree exp) +{ + if (!validate_arglist (exp, POINTER_TYPE, VOID_TYPE)) + return NULL_RTX; + + if (optimize < 1 || flag_no_inline) + return NULL_RTX; + + rtx stktop = NULL_RTX; + +#if 1 || defined RED_ZONE_SIZE + if (tree wmptr = (optimize + ? strub_watermark_parm (current_function_decl) + : NULL_TREE)) + { + tree wmtype = TREE_TYPE (TREE_TYPE (wmptr)); + tree wmtree = fold_build2 (MEM_REF, wmtype, wmptr, + build_int_cst (TREE_TYPE (wmptr), 0)); + rtx wmark = expand_expr (wmtree, NULL_RTX, ptr_mode, EXPAND_MEMORY); + stktop = force_reg (ptr_mode, wmark); + } +#endif + + if (!stktop) + stktop = expand_builtin_stack_address (); + + tree wmptr = CALL_EXPR_ARG (exp, 0); + tree wmtype = TREE_TYPE (TREE_TYPE (wmptr)); + tree wmtree = fold_build2 (MEM_REF, wmtype, wmptr, + build_int_cst (TREE_TYPE (wmptr), 0)); + rtx wmark = expand_expr (wmtree, NULL_RTX, ptr_mode, EXPAND_MEMORY); + + emit_move_insn (wmark, stktop); + + return const0_rtx; +} + +/* Expand a call to builtin function __builtin_strub_update. */ + +static rtx +expand_builtin_strub_update (tree exp) +{ + if (!validate_arglist (exp, POINTER_TYPE, VOID_TYPE)) + return NULL_RTX; + + if (optimize < 2 || flag_no_inline) + return NULL_RTX; + + rtx stktop = expand_builtin_stack_address (); + +#ifdef RED_ZONE_SIZE + /* Here's how the strub enter, update and leave functions deal with red zones. + + If it weren't for red zones, update, called from within a strub context, + would bump the watermark to the top of the stack. Enter and leave, running + in the caller, would use the caller's top of stack address both to + initialize the watermark passed to the callee, and to start strubbing the + stack afterwards. + + Ideally, we'd update the watermark so as to cover the used amount of red + zone, and strub starting at the caller's other end of the (presumably + unused) red zone. Normally, only leaf functions use the red zone, but at + this point we can't tell whether a function is a leaf, nor can we tell how + much of the red zone it uses. Furthermore, some strub contexts may have + been inlined so that update and leave are called from the same stack frame, + and the strub builtins may all have been inlined, turning a strub function + into a leaf. + + So cleaning the range from the caller's stack pointer (one end of the red + zone) to the (potentially inlined) callee's (other end of the) red zone + could scribble over the caller's own red zone. + + We avoid this possibility by arranging for callers that are strub contexts + to use their own watermark as the strub starting point. So, if A calls B, + and B calls C, B will tell A to strub up to the end of B's red zone, and + will strub itself only the part of C's stack frame and red zone that + doesn't overlap with B's. With that, we don't need to know who's leaf and + who isn't: inlined calls will shrink their strub window to zero, each + remaining call will strub some portion of the stack, and eventually the + strub context will return to a caller that isn't a strub context itself, + that will therefore use its own stack pointer as the strub starting point. + It's not a leaf, because strub contexts can't be inlined into non-strub + contexts, so it doesn't use the red zone, and it will therefore correctly + strub up the callee's stack frame up to the end of the callee's red zone. + Neat! */ + if (true /* (flags_from_decl_or_type (current_function_decl) & ECF_LEAF) */) + { + poly_int64 red_zone_size = RED_ZONE_SIZE; +#if STACK_GROWS_DOWNWARD + red_zone_size = -red_zone_size; +#endif + stktop = plus_constant (ptr_mode, stktop, red_zone_size); + stktop = force_reg (ptr_mode, stktop); + } +#endif + + tree wmptr = CALL_EXPR_ARG (exp, 0); + tree wmtype = TREE_TYPE (TREE_TYPE (wmptr)); + tree wmtree = fold_build2 (MEM_REF, wmtype, wmptr, + build_int_cst (TREE_TYPE (wmptr), 0)); + rtx wmark = expand_expr (wmtree, NULL_RTX, ptr_mode, EXPAND_MEMORY); + + rtx wmarkr = force_reg (ptr_mode, wmark); + + rtx_code_label *lab = gen_label_rtx (); + do_compare_rtx_and_jump (stktop, wmarkr, STACK_TOPS, STACK_UNSIGNED, + ptr_mode, NULL_RTX, lab, NULL, + profile_probability::very_likely ()); + emit_move_insn (wmark, stktop); + +#if 1 || defined RED_ZONE_SIZE + /* If this is an inlined strub function, also bump the watermark for the + enclosing function. This avoids a problem with the following scenario: A + calls B and B calls C, and both B and C get inlined into A. B allocates + temporary stack space before calling C. If we don't update A's watermark, + we may use an outdated baseline for the post-C strub_leave, erasing B's + temporary stack allocation. We only need this if we're fully expanding + strub_leave inline. */ + tree xwmptr = (optimize > 2 + ? strub_watermark_parm (current_function_decl) + : wmptr); + if (wmptr != xwmptr) + { + wmptr = xwmptr; + wmtype = TREE_TYPE (TREE_TYPE (wmptr)); + wmtree = fold_build2 (MEM_REF, wmtype, wmptr, + build_int_cst (TREE_TYPE (wmptr), 0)); + wmark = expand_expr (wmtree, NULL_RTX, ptr_mode, EXPAND_MEMORY); + wmarkr = force_reg (ptr_mode, wmark); + + do_compare_rtx_and_jump (stktop, wmarkr, STACK_TOPS, STACK_UNSIGNED, + ptr_mode, NULL_RTX, lab, NULL, + profile_probability::very_likely ()); + emit_move_insn (wmark, stktop); + } +#endif + + emit_label (lab); + + return const0_rtx; +} + + +/* Expand a call to builtin function __builtin_strub_leave. */ + +static rtx +expand_builtin_strub_leave (tree exp) +{ + if (!validate_arglist (exp, POINTER_TYPE, VOID_TYPE)) + return NULL_RTX; + + if (optimize < 2 || optimize_size || flag_no_inline) + return NULL_RTX; + + rtx stktop = NULL_RTX; + +#if 1 || defined RED_ZONE_SIZE + if (tree wmptr = (optimize + ? strub_watermark_parm (current_function_decl) + : NULL_TREE)) + { + tree wmtype = TREE_TYPE (TREE_TYPE (wmptr)); + tree wmtree = fold_build2 (MEM_REF, wmtype, wmptr, + build_int_cst (TREE_TYPE (wmptr), 0)); + rtx wmark = expand_expr (wmtree, NULL_RTX, ptr_mode, EXPAND_MEMORY); + stktop = force_reg (ptr_mode, wmark); + } +#endif + + if (!stktop) + stktop = expand_builtin_stack_address (); + + tree wmptr = CALL_EXPR_ARG (exp, 0); + tree wmtype = TREE_TYPE (TREE_TYPE (wmptr)); + tree wmtree = fold_build2 (MEM_REF, wmtype, wmptr, + build_int_cst (TREE_TYPE (wmptr), 0)); + rtx wmark = expand_expr (wmtree, NULL_RTX, ptr_mode, EXPAND_MEMORY); + + rtx wmarkr = force_reg (ptr_mode, wmark); + +#ifndef STACK_GROWS_DOWNWARD + rtx base = stktop; + rtx end = wmarkr; +#else + rtx base = wmarkr; + rtx end = stktop; +#endif + + /* We're going to modify it, so make sure it's not e.g. the stack pointer. */ + base = copy_to_reg (base); + + rtx_code_label *done = gen_label_rtx (); + do_compare_rtx_and_jump (base, end, LT, STACK_UNSIGNED, + ptr_mode, NULL_RTX, done, NULL, + profile_probability::very_likely ()); + + if (optimize < 3) + expand_call (exp, NULL_RTX, true); + else + { + /* Ok, now we've determined we want to copy the block, so convert the + addresses to Pmode, as needed to dereference them to access ptr_mode + memory locations, so that we don't have to convert anything within the + loop. */ + base = memory_address (ptr_mode, base); + end = memory_address (ptr_mode, end); + + rtx zero = force_operand (const0_rtx, NULL_RTX); + int ulen = GET_MODE_SIZE (ptr_mode); + rtx incr = plus_constant (Pmode, base, ulen); + rtx dstm = gen_rtx_MEM (ptr_mode, base); + + rtx_code_label *loop = gen_label_rtx (); + emit_label (loop); + emit_move_insn (dstm, zero); + emit_move_insn (base, force_operand (incr, NULL_RTX)); + do_compare_rtx_and_jump (base, end, LT, STACK_UNSIGNED, + Pmode, NULL_RTX, NULL, loop, + profile_probability::very_likely ()); + } + + emit_label (done); + + return const0_rtx; +} + /* Expand EXP, a call to the alloca builtin. Return NULL_RTX if we failed and the caller should emit a normal call. */ @@ -7110,6 +7362,27 @@ expand_builtin (tree exp, rtx target, rtx subtarget, machine_mode mode, case BUILT_IN_RETURN_ADDRESS: return expand_builtin_frame_address (fndecl, exp); + case BUILT_IN_STACK_ADDRESS: + return expand_builtin_stack_address (); + + case BUILT_IN___STRUB_ENTER: + target = expand_builtin_strub_enter (exp); + if (target) + return target; + break; + + case BUILT_IN___STRUB_UPDATE: + target = expand_builtin_strub_update (exp); + if (target) + return target; + break; + + case BUILT_IN___STRUB_LEAVE: + target = expand_builtin_strub_leave (exp); + if (target) + return target; + break; + /* Returns the address of the area where the structure is returned. 0 otherwise. */ case BUILT_IN_AGGREGATE_INCOMING_ADDRESS: diff --git a/gcc/builtins.def b/gcc/builtins.def index 45a09b4d42def..f83c1f5fcd7ed 100644 --- a/gcc/builtins.def +++ b/gcc/builtins.def @@ -874,6 +874,10 @@ DEF_EXT_LIB_BUILTIN (BUILT_IN_FFSL, "ffsl", BT_FN_INT_LONG, ATTR_CONST_NOTHRO DEF_EXT_LIB_BUILTIN (BUILT_IN_FFSLL, "ffsll", BT_FN_INT_LONGLONG, ATTR_CONST_NOTHROW_LEAF_LIST) DEF_EXT_LIB_BUILTIN (BUILT_IN_FORK, "fork", BT_FN_PID, ATTR_NOTHROW_LIST) DEF_GCC_BUILTIN (BUILT_IN_FRAME_ADDRESS, "frame_address", BT_FN_PTR_UINT, ATTR_NULL) +DEF_GCC_BUILTIN (BUILT_IN_STACK_ADDRESS, "stack_address", BT_FN_PTR, ATTR_NULL) +DEF_BUILTIN_STUB (BUILT_IN___STRUB_ENTER, "__builtin___strub_enter") +DEF_BUILTIN_STUB (BUILT_IN___STRUB_UPDATE, "__builtin___strub_update") +DEF_BUILTIN_STUB (BUILT_IN___STRUB_LEAVE, "__builtin___strub_leave") /* [trans-mem]: Adjust BUILT_IN_TM_FREE if BUILT_IN_FREE is changed. */ DEF_LIB_BUILTIN (BUILT_IN_FREE, "free", BT_FN_VOID_PTR, ATTR_NOTHROW_LEAF_LIST) DEF_GCC_BUILTIN (BUILT_IN_FROB_RETURN_ADDR, "frob_return_addr", BT_FN_PTR_PTR, ATTR_NULL) diff --git a/gcc/c-family/c-attribs.c b/gcc/c-family/c-attribs.c index d14e9c441b39b..0453ac563cc40 100644 --- a/gcc/c-family/c-attribs.c +++ b/gcc/c-family/c-attribs.c @@ -41,6 +41,7 @@ along with GCC; see the file COPYING3. If not see #include "common/common-target.h" #include "langhooks.h" #include "tree-inline.h" +#include "ipa-strub.h" #include "toplev.h" #include "tree-iterator.h" #include "opts.h" @@ -69,6 +70,7 @@ static tree handle_asan_odr_indicator_attribute (tree *, tree, tree, int, static tree handle_stack_protect_attribute (tree *, tree, tree, int, bool *); static tree handle_no_stack_protector_function_attribute (tree *, tree, tree, int, bool *); +static tree handle_strub_attribute (tree *, tree, tree, int, bool *); static tree handle_noinline_attribute (tree *, tree, tree, int, bool *); static tree handle_noclone_attribute (tree *, tree, tree, int, bool *); static tree handle_nocf_check_attribute (tree *, tree, tree, int, bool *); @@ -308,6 +310,8 @@ const struct attribute_spec c_common_attribute_table[] = { "no_stack_protector", 0, 0, true, false, false, false, handle_no_stack_protector_function_attribute, attr_stack_protect_exclusions }, + { "strub", 0, 1, false, true, false, true, + handle_strub_attribute, NULL }, { "noinline", 0, 0, true, false, false, false, handle_noinline_attribute, attr_noinline_exclusions }, @@ -1294,6 +1298,70 @@ handle_noipa_attribute (tree *node, tree name, tree, int, bool *no_add_attrs) return NULL_TREE; } +/* Handle a "strub" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_strub_attribute (tree *node, tree name, + tree args, + int ARG_UNUSED (flags), bool *no_add_attrs) +{ + bool enable = true; + + if (args + && POINTER_TYPE_P (*node) + && FUNC_OR_METHOD_TYPE_P (TREE_TYPE (*node))) + *node = TREE_TYPE (*node); + + if (args && FUNC_OR_METHOD_TYPE_P (*node)) + { + switch (strub_validate_fn_attr_parm (TREE_VALUE (args))) + { + case 1: + case 2: + enable = true; + break; + + case 0: + warning (OPT_Wattributes, + "%qE attribute ignored because of argument %qE", + name, TREE_VALUE (args)); + *no_add_attrs = true; + enable = false; + break; + + case -1: + case -2: + enable = false; + break; + + default: + gcc_unreachable (); + } + + args = TREE_CHAIN (args); + } + + if (args) + { + warning (OPT_Wattributes, + "ignoring attribute %qE because of excess arguments" + " starting at %qE", + name, TREE_VALUE (args)); + *no_add_attrs = true; + enable = false; + } + + /* If we see a strub-enabling attribute, and we're at the default setting, + implicitly or explicitly, note that the attribute was seen, so that we can + reduce the compile-time overhead to nearly zero when the strub feature is + not used. */ + if (enable && flag_strub < -2) + flag_strub += 2; + + return NULL_TREE; +} + /* Handle a "noinline" attribute; arguments as in struct attribute_spec.handler. */ diff --git a/gcc/common.opt b/gcc/common.opt index 7d69ab5ef7c3d..ef018ebf73512 100644 --- a/gcc/common.opt +++ b/gcc/common.opt @@ -2687,6 +2687,35 @@ fstrict-overflow Common Treat signed overflow as undefined. Negated as -fwrapv -fwrapv-pointer. +fstrub=disable +Common RejectNegative Var(flag_strub, 0) +Disable stack scrub entirely, disregarding strub attributes. + +fstrub=strict +Common RejectNegative Var(flag_strub, -4) +Enable stack scrub as per attributes, with strict call checking. + +; If any strub-enabling attribute is seen when the default or strict +; initializer values are in effect, flag_strub is bumped up by 2. The +; scrub mode gate function will then bump these initializer values to +; 0 if no strub-enabling attribute is seen. This minimizes the strub +; overhead. +fstrub=relaxed +Common RejectNegative Var(flag_strub, -3) Init(-3) +Restore default strub mode: as per attributes, with relaxed checking. + +fstrub=all +Common RejectNegative Var(flag_strub, 3) +Enable stack scrubbing for all viable functions. + +fstrub=at-calls +Common RejectNegative Var(flag_strub, 1) +Enable at-calls stack scrubbing for all viable functions. + +fstrub=internal +Common RejectNegative Var(flag_strub, 2) +Enable internal stack scrubbing for all viable functions. + fsync-libcalls Common Var(flag_sync_libcalls) Init(1) Implement __atomic operations via libcalls to legacy __sync functions. diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi index 7fb22ed806323..d85e695d85cc0 100644 --- a/gcc/doc/extend.texi +++ b/gcc/doc/extend.texi @@ -77,6 +77,7 @@ extensions, accepted by GCC in C90 mode and in C++. * Function Names:: Printable strings which are the name of the current function. * Return Address:: Getting the return or frame address of a function. +* Stack Scrubbing:: Stack scrubbing internal interfaces. * Vector Extensions:: Using vector instructions through built-in functions. * Offsetof:: Special syntax for implementing @code{offsetof}. * __sync Builtins:: Legacy built-in functions for atomic memory access. @@ -8725,6 +8726,263 @@ pid_t wait (wait_status_ptr_t p) @} @end smallexample +@item strub +@cindex @code{strub} type attribute +This attribute defines stack-scrubbing properties of functions and +variables. Being a type attribute, it attaches to types, even when +specified in function and variable declarations. When applied to +function types, it takes an optional string argument. When applied to a +pointer-to-function type, if the optional argument is given, it gets +propagated to the function type. + +@smallexample +/* A strub variable. */ +int __attribute__ ((strub)) var; +/* A strub variable that happens to be a pointer. */ +__attribute__ ((strub)) int *strub_ptr_to_int; +/* A pointer type that may point to a strub variable. */ +typedef int __attribute__ ((strub)) *ptr_to_strub_int_type; + +/* A declaration of a strub function. */ +extern int __attribute__ ((strub)) foo (void); +/* A pointer to that strub function. */ +int __attribute__ ((strub ("at-calls"))) (*ptr_to_strub_fn)(void) = foo; +@end smallexample + +A function associated with @code{at-calls} @code{strub} mode +(@code{strub("at-calls")}, or just @code{strub}) undergoes interface +changes. Its callers are adjusted to match the changes, and to scrub +(overwrite with zeros) the stack space used by the called function after +it returns. The interface change makes the function type incompatible +with an unadorned but otherwise equivalent type, so @emph{every} +declaration and every type that may be used to call the function must be +associated with this strub mode. + +A function associated with @code{internal} @code{strub} mode +(@code{strub("internal")}) retains an unmodified, type-compatible +interface, but it may be turned into a wrapper that calls the wrapped +body using a custom interface. The wrapper then scrubs the stack space +used by the wrapped body. Though the wrapped body has its stack space +scrubbed, the wrapper does not, so arguments and return values may +remain unscrubbed even when such a function is called by another +function that enables @code{strub}. This is why, when compiling with +@option{-fstrub=strict}, a @code{strub} context is not allowed to call +@code{internal} @code{strub} functions. + +@smallexample +/* A declaration of an internal-strub function. */ +extern int __attribute__ ((strub ("internal"))) bar (void); + +int __attribute__ ((strub)) +baz (void) +@{ + /* Ok, foo was declared above as an at-calls strub function. */ + foo (); + /* Not allowed in strict mode, otherwise allowed. */ + bar (); +@} +@end smallexample + +An automatically-allocated variable associated with the @code{strub} +attribute causes the (immediately) enclosing function to have +@code{strub} enabled. + +A statically-allocated variable associated with the @code{strub} +attribute causes functions that @emph{read} it, through its @code{strub} +data type, to have @code{strub} enabled. Reading data by dereferencing +a pointer to a @code{strub} data type has the same effect. Note: The +attribute does not carry over from a composite type to the types of its +components, so the intended effect may not be obtained with non-scalar +types. + +When selecting a @code{strub}-enabled mode for a function that is not +explicitly associated with one, because of @code{strub} variables or +data pointers, the function must satisfy @code{internal} mode viability +requirements (see below), even when @code{at-calls} mode is also viable +and, being more efficient, ends up selected as an optimization. + +@smallexample +/* zapme is implicitly strub-enabled because of strub variables. + Optimization may change its strub mode, but not the requirements. */ +static int +zapme (int i) +@{ + /* A local strub variable enables strub. */ + int __attribute__ ((strub)) lvar; + /* Reading strub data through a pointer-to-strub enables strub. */ + lvar = * (ptr_to_strub_int_type) &i; + /* Writing to a global strub variable does not enable strub. */ + var = lvar; + /* Reading from a global strub variable enables strub. */ + return var; +@} +@end smallexample + +A @code{strub} context is the body (as opposed to the interface) of a +function that has @code{strub} enabled, be it explicitly, by +@code{at-calls} or @code{internal} mode, or implicitly, due to +@code{strub} variables or command-line options. + +A function of a type associated with the @code{disabled} @code{strub} +mode (@code{strub("disabled")} will not have its own stack space +scrubbed. Such functions @emph{cannot} be called from within +@code{strub} contexts. + +In order to enable a function to be called from within @code{strub} +contexts without having its stack space scrubbed, associate it with the +@code{callable} @code{strub} mode (@code{strub("callable")}). + +When a function is not assigned a @code{strub} mode, explicitly or +implicitly, the mode defaults to @code{callable}, except when compiling +with @option{-fstrub=strict}, that causes @code{strub} mode to default +to @code{disabled}. + +@example +extern int __attribute__ ((strub ("callable"))) bac (void); +extern int __attribute__ ((strub ("disabled"))) bad (void); + /* Implicitly disabled with -fstrub=strict, otherwise callable. */ +extern int bah (void); + +int __attribute__ ((strub)) +bal (void) +@{ + /* Not allowed, bad is not strub-callable. */ + bad (); + /* Ok, bac is strub-callable. */ + bac (); + /* Not allowed with -fstrub=strict, otherwise allowed. */ + bah (); +@} +@end example + +Function types marked @code{callable} and @code{disabled} are not +mutually compatible types, but the underlying interfaces are compatible, +so it is safe to convert pointers between them, and to use such pointers +or alternate declarations to call them. Interfaces are also +interchangeable between them and @code{internal} (but not +@code{at-calls}!), but adding @code{internal} to a pointer type will not +cause the pointed-to function to perform stack scrubbing. + +@example +void __attribute__ ((strub)) +bap (void) +@{ + /* Assign a callable function to pointer-to-disabled. + Flagged as not quite compatible with -Wpedantic. */ + int __attribute__ ((strub ("disabled"))) (*d_p) (void) = bac; + /* Not allowed: calls disabled type in a strub context. */ + d_p (); + + /* Assign a disabled function to pointer-to-callable. + Flagged as not quite compatible with -Wpedantic. */ + int __attribute__ ((strub ("callable"))) (*c_p) (void) = bad; + /* Ok, safe. */ + c_p (); + + /* Assign an internal function to pointer-to-callable. + Flagged as not quite compatible with -Wpedantic. */ + c_p = bar; + /* Ok, safe. */ + c_p (); + + /* Assign an at-calls function to pointer-to-callable. + Flaggged as incompatible. */ + c_p = bal; + /* The call through an interface-incompatible type will not use the + modified interface expected by the at-calls function, so it is + likely to misbehave at runtime. */ + c_p (); +@} +@end example + +@code{Strub} contexts are never inlined into non-@code{strub} contexts. +When an @code{internal}-strub function is split up, the wrapper can +often be inlined, but the wrapped body @emph{never} is. A function +marked as @code{always_inline}, even if explicitly assigned +@code{internal} strub mode, will not undergo wrapping, so its body gets +inlined as required. + +@example +inline int __attribute__ ((strub ("at-calls"))) +inl_atc (void) +@{ + /* This body may get inlined into strub contexts. */ +@} + +inline int __attribute__ ((strub ("internal"))) +inl_int (void) +@{ + /* This body NEVER gets inlined, though its wrapper may. */ +@} + +inline int __attribute__ ((strub ("internal"), always_inline)) +inl_int_ali (void) +@{ + /* No internal wrapper, so this body ALWAYS gets inlined, + but it cannot be called from non-strub contexts. */ +@} + +void __attribute__ ((strub ("disabled"))) +bat (void) +@{ + /* Not allowed, cannot inline into a non-strub context. */ + inl_int_ali (); +@} +@end example + +@cindex strub eligibility and viability +Some @option{-fstrub=*} command line options enable @code{strub} modes +implicitly where viable. A @code{strub} mode is only viable for a +function if the function is eligible for that mode, and if other +conditions, detailed below, are satisfied. If it's not eligible for a +mode, attempts to explicitly associate it with that mode are rejected +with an error message. If it is eligible, that mode may be assigned +explicitly through this attribute, but implicit assignment through +command-line options may involve additional viability requirements. + +A function is ineligible for @code{at-calls} @code{strub} mode if a +different @code{strub} mode is explicitly requested, if attribute +@code{noipa} is present, or if it calls @code{__builtin_apply_args}. +@code{At-calls} @code{strub} mode, if not requested through the function +type, is only viable for an eligible function if the function is not +visible to other translation units, and if it doesn't have its address +taken. + +@smallexample +/* bar is eligible for at-calls strub mode, + but not viable for that mode because it is visible to other units. + It is eligible and viable for internal strub mode. */ +void bav () @{@} + +/* setp is eligible for at-calls strub mode, + but not viable for that mode because its address is taken. + It is eligible and viable for internal strub mode. */ +void setp (void) @{ static void (*p)(void); = setp; @} +@end smallexample + +A function is ineligible for @code{internal} @code{strub} mode if a +different @code{strub} mode is explicitly requested, or if attribute +@code{noipa} is present. For an @code{always_inline} function, meeting +these requirements is enough to make it eligible. Any function that has +attribute @code{noclone}, that uses such extensions as non-local labels, +computed gotos, alternate variable argument passing interfaces, +@code{__builtin_next_arg}, or @code{__builtin_return_address}, or that +takes too many (about 64Ki) arguments is ineligible, unless it is +@code{always_inline}. For @code{internal} @code{strub} mode, all +eligible functions are viable. + +@smallexample +/* flop is not eligible, thus not viable, for at-calls strub mode. + Likewise for internal strub mode. */ +__attribute__ ((noipa)) void flop (void) @{@} + +/* flip is eligible and viable for at-calls strub mode. + It would be ineligible for internal strub mode, because of noclone, + if it weren't for always_inline. With always_inline, noclone is not + an obstacle, so it is also eligible and viable for internal strub mode. */ +inline __attribute__ ((noclone, always_inline)) void flip (void) @{@} +@end smallexample + @item unused @cindex @code{unused} type attribute When attached to a type (including a @code{union} or a @code{struct}), @@ -11749,6 +12007,55 @@ option is in effect. Such calls should only be made in debugging situations. @end deftypefn +@deftypefn {Built-in Function} {void *} __builtin_stack_address () +This function returns the value of the stack pointer register. +@end deftypefn + +@node Stack Scrubbing +@section Stack scrubbing internal interfaces + +Stack scrubbing involves cooperation between a @code{strub} context, +i.e., a function whose stack frame is to be zeroed-out, and its callers. +The caller initializes a stack watermark, the @code{strub} context +updates the watermark according to its stack use, and the caller zeroes +it out once it regains control, whether by the callee's returning or by +an exception. + +Each of these steps is performed by a different builtin function call. +Calls to these builtins are introduced automatically, in response to +@code{strub} attributes and command-line options; they are not expected +to be explicitly called by source code. + +The functions that implement the builtins are available in libgcc but, +depending on optimization levels, they are expanded internally, adjusted +to account for inlining, and sometimes combined/deferred (e.g. passing +the caller-supplied watermark on to callees, refraining from erasing +stack areas that the caller will) to enable tail calls and to optimize +for code size. + +@deftypefn {Built-in Function} {void} __builtin___strub_enter (void **@var{wmptr}) +This function initializes a stack @var{watermark} variable with the +current top of the stack. A call to this builtin function is introduced +before entering a @code{strub} context. It remains as a function call +if optimization is not enabled. +@end deftypefn + +@deftypefn {Built-in Function} {void} __builtin___strub_update (void **@var{wmptr}) +This function updates a stack @var{watermark} variable with the current +top of the stack, if it tops the previous watermark. A call to this +builtin function is inserted within @code{strub} contexts, whenever +additional stack space may have been used. It remains as a function +call at optimization levels lower than 2. +@end deftypefn + +@deftypefn {Built-in Function} {void} __builtin___strub_leave (void **@var{wmptr}) +This function overwrites the memory area between the current top of the +stack, and the @var{watermark}ed address. A call to this builtin +function is inserted after leaving a @code{strub} context. It remains +as a function call at optimization levels lower than 3, and it is guarded by +a condition at level 2. +@end deftypefn + @node Vector Extensions @section Using Vector Instructions through Built-in Functions diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 8969bac664d31..afcb37914acb1 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -599,6 +599,8 @@ Objective-C and Objective-C++ Dialects}. -fstack-protector-explicit -fstack-check @gol -fstack-limit-register=@var{reg} -fstack-limit-symbol=@var{sym} @gol -fno-stack-limit -fsplit-stack @gol +-fstrub=disable -fstrub=strict -fstrub=relaxed @gol +-fstrub=all -fstrub=at-calls -fstrub=internal @gol -fvtable-verify=@r{[}std@r{|}preinit@r{|}none@r{]} @gol -fvtv-counts -fvtv-debug @gol -finstrument-functions @gol @@ -15512,6 +15514,56 @@ without @option{-fsplit-stack} always has a large stack. Support for this is implemented in the gold linker in GNU binutils release 2.21 and later. +@item -fstrub=disable +@opindex -fstrub=disable +Disable stack scrubbing entirely, ignoring any @code{strub} attributes. +See @xref{Common Type Attributes}. + +@item -fstrub=strict +@opindex fstrub=strict +Functions default to @code{strub} mode @code{disabled}, and apply +@option{strict}ly the restriction that only functions associated with +@code{strub}-@code{callable} modes (@code{at-calls}, @code{callable} and +@code{always_inline} @code{internal}) are @code{callable} by functions +with @code{strub}-enabled modes (@code{at-calls} and @code{internal}). + +@item -fstrub=relaxed +@opindex fstrub=relaxed +Restore the default stack scrub (@code{strub}) setting, namely, +@code{strub} is only enabled as required by @code{strub} attributes +associated with function and data types. @code{Relaxed} means that +strub contexts are only prevented from calling functions explicitly +associated with @code{strub} mode @code{disabled}. This option is only +useful to override other @option{-fstrub=*} options that precede it in +the command line. + +@item -fstrub=at-calls +@opindex fstrub=at-calls +Enable @code{at-calls} @code{strub} mode where viable. The primary use +of this option is for testing. It exercises the @code{strub} machinery +in scenarios strictly local to a translation unit. This @code{strub} +mode modifies function interfaces, so any function that is visible to +other translation units, or that has its address taken, will @emph{not} +be affected by this option. Optimization options may also affect +viability. See the @code{strub} attribute documentation for details on +viability and eligibility requirements. + +@item -fstrub=internal +@opindex fstrub=internal +Enable @code{internal} @code{strub} mode where viable. The primary use +of this option is for testing. This option is intended to exercise +thoroughly parts of the @code{strub} machinery that implement the less +efficient, but interface-preserving @code{strub} mode. Functions that +would not be affected by this option are quite uncommon. + +@item -fstrub=all +@opindex fstrub=all +Enable some @code{strub} mode where viable. When both strub modes are +viable, @code{at-calls} is preferred. @option{-fdump-ipa-strubm} adds +function attributes that tell which mode was selected for each function. +The primary use of this option is for testing, to exercise thoroughly +the @code{strub} machinery. + @item -fvtable-verify=@r{[}std@r{|}preinit@r{|}none@r{]} @opindex fvtable-verify This option is only available when compiling C++ code. @@ -17385,6 +17437,14 @@ and inlining decisions. @item inline Dump after function inlining. +@item strubm +Dump after selecting @code{strub} modes, and recording the selections as +function attributes. + +@item strub +Dump @code{strub} transformations: interface changes, function wrapping, +and insertion of builtin calls for stack scrubbing and watermarking. + @end table Additionally, the options @option{-optimized}, @option{-missed}, diff --git a/gcc/ipa-inline.c b/gcc/ipa-inline.c index 413446bcc46cd..932e49dba8ef6 100644 --- a/gcc/ipa-inline.c +++ b/gcc/ipa-inline.c @@ -119,6 +119,7 @@ along with GCC; see the file COPYING3. If not see #include "stringpool.h" #include "attribs.h" #include "asan.h" +#include "ipa-strub.h" typedef fibonacci_heap edge_heap_t; typedef fibonacci_node edge_heap_node_t; @@ -396,6 +397,11 @@ can_inline_edge_p (struct cgraph_edge *e, bool report, e->inline_failed = CIF_SANITIZE_ATTRIBUTE_MISMATCH; inlinable = false; } + if (!strub_inlinable_to_p (callee, caller)) + { + e->inline_failed = CIF_UNSPECIFIED; + inlinable = false; + } if (!inlinable && report) report_inline_failed_reason (e); return inlinable; diff --git a/gcc/ipa-split.c b/gcc/ipa-split.c index c68577d04a994..8c880747eb7a3 100644 --- a/gcc/ipa-split.c +++ b/gcc/ipa-split.c @@ -104,6 +104,7 @@ along with GCC; see the file COPYING3. If not see #include "ipa-fnsummary.h" #include "cfgloop.h" #include "attribs.h" +#include "ipa-strub.h" /* Per basic block info. */ @@ -1792,6 +1793,12 @@ execute_split_functions (void) "section.\n"); return 0; } + if (!strub_splittable_p (node)) + { + if (dump_file) + fprintf (dump_file, "Not splitting: function is a strub context.\n"); + return 0; + } /* We enforce splitting after loop headers when profile info is not available. */ diff --git a/gcc/ipa-strub.c b/gcc/ipa-strub.c new file mode 100644 index 0000000000000..663fe7b2920d2 --- /dev/null +++ b/gcc/ipa-strub.c @@ -0,0 +1,3336 @@ +/* strub (stack scrubbing) support. + Copyright (C) 2021 Free Software Foundation, Inc. + Contributed by Alexandre Oliva . + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 3, or (at your option) any later +version. + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING3. If not see +. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "backend.h" +#include "tree.h" +#include "gimple.h" +#include "gimplify.h" +#include "tree-pass.h" +#include "ssa.h" +#include "gimple-iterator.h" +#include "gimplify-me.h" +#include "tree-into-ssa.h" +#include "tree-ssa.h" +#include "tree-cfg.h" +#include "cfghooks.h" +#include "cfgloop.h" +#include "cfgcleanup.h" +#include "tree-eh.h" +#include "except.h" +#include "builtins.h" +#include "attribs.h" +#include "tree-inline.h" +#include "cgraph.h" +#include "alloc-pool.h" +#include "symbol-summary.h" +#include "ipa-prop.h" +#include "ipa-fnsummary.h" +#include "gimple-fold.h" +#include "fold-const.h" +#include "gimple-walk.h" +#include "tree-dfa.h" +#include "langhooks.h" +#include "calls.h" +#include "vec.h" +#include "stor-layout.h" +#include "varasm.h" +#include "alias.h" +#include "diagnostic.h" +#include "intl.h" +#include "ipa-strub.h" + +#if BUILDING_GCC_MAJOR >= 11 +# include "symtab-thunks.h" +# include "attr-fnspec.h" +# define HAVE_ATTR_FNSPEC 1 +# define FOR_GCC_11P 1 +#else +# define HAVE_ATTR_FNSPEC 0 +# define FOR_GCC_11P 0 +#endif + +/* Const and pure functions that gain a watermark parameter for strub purposes + are still regarded as such, which may cause the inline expansions of the + __strub builtins to malfunction. Ideally, attribute "fn spec" would enable + us to inform the backend about requirements and side effects of the call, but + call_fusage building in calls.c:expand_call does not even look at + attr_fnspec, so we resort to asm loads and updates to attain an equivalent + effect. Once expand_call gains the ability to issue extra memory uses and + clobbers based on pure/const function's fnspec, we can define this to 1. */ +#define ATTR_FNSPEC_DECONST_WATERMARK 0 + +enum strub_mode { + /* This mode denotes a regular function, that does not require stack + scrubbing (strubbing). It may call any other functions, but if + it calls AT_CALLS (or WRAPPED) ones, strubbing logic is + automatically introduced around those calls (the latter, by + inlining INTERNAL wrappers). */ + STRUB_DISABLED = 0, + + /* This denotes a function whose signature is (to be) modified to + take an extra parameter, for stack use annotation, and its + callers must initialize and pass that argument, and perform the + strubbing. Functions that are explicitly marked with attribute + strub must have the mark visible wherever the function is, + including aliases, and overriders and overriding methods. + Functions that are implicitly marked for strubbing, for accessing + variables explicitly marked as such, will only select this + strubbing method if they are internal to a translation unit. It + can only be inlined into other strubbing functions, i.e., + STRUB_AT_CALLS or STRUB_WRAPPED. */ + STRUB_AT_CALLS = 1, + + /* This denotes a function that is to perform strubbing internally, + without any changes to its interface (the function is turned into + a strubbing wrapper, and its original body is moved to a separate + STRUB_WRAPPED function, with a modified interface). Functions + may be explicitly marked with attribute strub(2), and the + attribute must be visible at the point of definition. Functions + that are explicitly marked for strubbing, for accessing variables + explicitly marked as such, may select this strubbing mode if + their interface cannot change, e.g. because its interface is + visible to other translation units, directly, by indirection + (having its address taken), inheritance, etc. Functions that use + this method must not have the noclone attribute, nor the noipa + one. Functions marked as always_inline may select this mode, but + they are NOT wrapped, they remain unchanged, and are only inlined + into strubbed contexts. Once non-always_inline functions are + wrapped, the wrapper becomes STRUB_WRAPPER, and the wrapped becomes + STRUB_WRAPPED. */ + STRUB_INTERNAL = 2, + + /* This denotes a function whose stack is not strubbed, but that is + nevertheless explicitly or implicitly marked as callable from strubbing + functions. Normally, only STRUB_AT_CALLS (and STRUB_INTERNAL -> + STRUB_WRAPPED) functions can be called from strubbing contexts (bodies of + STRUB_AT_CALLS, STRUB_INTERNAL and STRUB_WRAPPED functions), but attribute + strub(3) enables other functions to be (indirectly) called from these + contexts. Some builtins and internal functions may be implicitly marked as + STRUB_CALLABLE. */ + STRUB_CALLABLE = 3, + + /* This denotes the function that took over the body of a + STRUB_INTERNAL function. At first, it's only called by its + wrapper, but the wrapper may be inlined. The wrapped function, + in turn, can only be inlined into other functions whose stack + frames are strubbed, i.e., that are STRUB_WRAPPED or + STRUB_AT_CALLS. */ + STRUB_WRAPPED = -1, + + /* This denotes the wrapper function that replaced the STRUB_INTERNAL + function. This mode overrides the STRUB_INTERNAL mode at the time the + internal to-be-wrapped function becomes a wrapper, so that inlining logic + can tell one from the other. */ + STRUB_WRAPPER = -2, + + /* This denotes an always_inline function that requires strubbing. It can + only be called from, and inlined into, other strubbing contexts. */ + STRUB_INLINABLE = -3, + + /* This denotes a function that accesses strub variables, so it would call for + internal strubbing (whether or not it's eligible for that), but since + at-calls strubbing is viable, that's selected as an optimization. This + mode addresses the inconvenience that such functions may have different + modes selected depending on optimization flags, and get a different + callable status depending on that choice: if we assigned them + STRUB_AT_CALLS mode, they would be callable when optimizing, whereas + STRUB_INTERNAL would not be callable. */ + STRUB_AT_CALLS_OPT = -4, + +}; + +/* Look up a strub attribute in TYPE, and return it. */ + +static tree +get_strub_attr_from_type (tree type) +{ + return lookup_attribute ("strub", TYPE_ATTRIBUTES (type)); +} + +/* Look up a strub attribute in DECL or in its type, and return it. */ + +static tree +get_strub_attr_from_decl (tree decl) +{ + tree ret = lookup_attribute ("strub", DECL_ATTRIBUTES (decl)); + if (ret) + return ret; + return get_strub_attr_from_type (TREE_TYPE (decl)); +} + +/* Define a function to cache identifier ID, to be used as a strub attribute + parameter for a strub mode named after NAME. */ +#define DEF_STRUB_IDS(NAME, ID) \ +static inline tree get_strub_mode_id_ ## NAME () { \ + static tree identifier = NULL_TREE; \ + if (!identifier) \ + identifier = get_identifier (ID); \ + return identifier; \ +} +/* Same as DEF_STRUB_IDS, but use the string expansion of NAME as ID. */ +#define DEF_STRUB_ID(NAME) \ +DEF_STRUB_IDS (NAME, #NAME) + +/* Define functions for each of the strub mode identifiers. + Expose dashes rather than underscores. */ +DEF_STRUB_ID (disabled) +DEF_STRUB_IDS (at_calls, "at-calls") +DEF_STRUB_ID (internal) +DEF_STRUB_ID (callable) +DEF_STRUB_ID (wrapped) +DEF_STRUB_ID (wrapper) +DEF_STRUB_ID (inlinable) +DEF_STRUB_IDS (at_calls_opt, "at-calls-opt") + +/* Release the temporary macro names. */ +#undef DEF_STRUB_IDS +#undef DEF_STRUB_ID + +/* Return the identifier corresponding to strub MODE. */ + +static tree +get_strub_mode_attr_parm (enum strub_mode mode) +{ + switch (mode) + { + case STRUB_DISABLED: + return get_strub_mode_id_disabled (); + + case STRUB_AT_CALLS: + return get_strub_mode_id_at_calls (); + + case STRUB_INTERNAL: + return get_strub_mode_id_internal (); + + case STRUB_CALLABLE: + return get_strub_mode_id_callable (); + + case STRUB_WRAPPED: + return get_strub_mode_id_wrapped (); + + case STRUB_WRAPPER: + return get_strub_mode_id_wrapper (); + + case STRUB_INLINABLE: + return get_strub_mode_id_inlinable (); + + case STRUB_AT_CALLS_OPT: + return get_strub_mode_id_at_calls_opt (); + + default: + gcc_unreachable (); + } +} + +/* Return the parmeters (TREE_VALUE) for a strub attribute of MODE. + We know we use a single parameter, so we bypass the creation of a + tree list. */ + +static tree +get_strub_mode_attr_value (enum strub_mode mode) +{ + return get_strub_mode_attr_parm (mode); +} + +/* Determine whether ID is a well-formed strub mode-specifying attribute + parameter for a function (type). Only user-visible modes are accepted, and + ID must be non-NULL. + + For unacceptable parms, return 0, otherwise a nonzero value as below. + + If the parm enables strub, return positive, otherwise negative. + + If the affected type must be a distinct, incompatible type,return an integer + of absolute value 2, otherwise 1. */ + +int +strub_validate_fn_attr_parm (tree id) +{ + int ret; + const char *s = NULL; + size_t len = 0; + + /* do NOT test for NULL. This is only to be called with non-NULL arguments. + We assume that the strub parameter applies to a function, because only + functions accept an explicit argument. If we accepted NULL, and we + happened to be called to verify the argument for a variable, our return + values would be wrong. */ + if (TREE_CODE (id) == STRING_CST) + { + s = TREE_STRING_POINTER (id); + len = TREE_STRING_LENGTH (id) - 1; + } + else if (TREE_CODE (id) == IDENTIFIER_NODE) + { + s = IDENTIFIER_POINTER (id); + len = IDENTIFIER_LENGTH (id); + } + else + return 0; + + enum strub_mode mode; + + if (len != 8) + return 0; + + switch (s[0]) + { + case 'd': + mode = STRUB_DISABLED; + ret = -1; + break; + + case 'a': + mode = STRUB_AT_CALLS; + ret = 2; + break; + + case 'i': + mode = STRUB_INTERNAL; + ret = 1; + break; + + case 'c': + mode = STRUB_CALLABLE; + ret = -2; + break; + + default: + /* Other parms are for internal use only. */ + return 0; + } + + tree mode_id = get_strub_mode_attr_parm (mode); + + if (TREE_CODE (id) == IDENTIFIER_NODE + ? id != mode_id + : strncmp (s, IDENTIFIER_POINTER (mode_id), len) != 0) + return 0; + + return ret; +} + +/* Return the strub mode from STRUB_ATTR. VAR_P should be true if the attribute + is taken from a variable, rather than from a function, or a type thereof. */ + +static enum strub_mode +get_strub_mode_from_attr (tree strub_attr, bool var_p = false) +{ + enum strub_mode mode = STRUB_DISABLED; + + if (strub_attr) + { + if (!TREE_VALUE (strub_attr)) + mode = !var_p ? STRUB_AT_CALLS : STRUB_INTERNAL; + else + { + gcc_checking_assert (!var_p); + tree id = TREE_VALUE (strub_attr); + if (TREE_CODE (id) == TREE_LIST) + id = TREE_VALUE (id); + const char *s = (TREE_CODE (id) == STRING_CST + ? TREE_STRING_POINTER (id) + : IDENTIFIER_POINTER (id)); + size_t len = (TREE_CODE (id) == STRING_CST + ? TREE_STRING_LENGTH (id) - 1 + : IDENTIFIER_LENGTH (id)); + + switch (len) + { + case 7: + switch (s[6]) + { + case 'r': + mode = STRUB_WRAPPER; + break; + + case 'd': + mode = STRUB_WRAPPED; + break; + + default: + gcc_unreachable (); + } + break; + + case 8: + switch (s[0]) + { + case 'd': + mode = STRUB_DISABLED; + break; + + case 'a': + mode = STRUB_AT_CALLS; + break; + + case 'i': + mode = STRUB_INTERNAL; + break; + + case 'c': + mode = STRUB_CALLABLE; + break; + + default: + gcc_unreachable (); + } + break; + + case 9: + mode = STRUB_INLINABLE; + break; + + case 12: + mode = STRUB_AT_CALLS_OPT; + break; + + default: + gcc_unreachable (); + } + + gcc_checking_assert (TREE_CODE (id) == IDENTIFIER_NODE + ? id == get_strub_mode_attr_parm (mode) + : strncmp (IDENTIFIER_POINTER + (get_strub_mode_attr_parm (mode)), + s, len) == 0); + } + } + + return mode; +} + +/* Look up, decode and return the strub mode associated with FNDECL. */ + +static enum strub_mode +get_strub_mode_from_fndecl (tree fndecl) +{ + return get_strub_mode_from_attr (get_strub_attr_from_decl (fndecl)); +} + +/* Look up, decode and return the strub mode associated with NODE. */ + +static enum strub_mode +get_strub_mode (cgraph_node *node) +{ + return get_strub_mode_from_fndecl (node->decl); +} + +/* Look up, decode and return the strub mode associated with TYPE. */ + +static enum strub_mode +get_strub_mode_from_type (tree type) +{ + bool var_p = !FUNC_OR_METHOD_TYPE_P (type); + tree attr = get_strub_attr_from_type (type); + + if (attr) + return get_strub_mode_from_attr (attr, var_p); + + if (flag_strub >= -1 && !var_p) + return STRUB_CALLABLE; + + return STRUB_DISABLED; +} + + +/* Return true iff NODE calls builtin va_start. */ + +static bool +calls_builtin_va_start_p (cgraph_node *node) +{ + bool result = false; + + for (cgraph_edge *e = node->callees; e; e = e->next_callee) + { + tree cdecl = e->callee->decl; + if (fndecl_built_in_p (cdecl, BUILT_IN_VA_START)) + return true; + } + + return result; +} + +/* Return true iff NODE calls builtin apply_args, and optionally REPORT it. */ + +static bool +calls_builtin_apply_args_p (cgraph_node *node, bool report = false) +{ + bool result = false; + + for (cgraph_edge *e = node->callees; e; e = e->next_callee) + { + tree cdecl = e->callee->decl; + if (!fndecl_built_in_p (cdecl, BUILT_IN_APPLY_ARGS)) + continue; + + result = true; + + if (!report) + break; + + sorry_at (gimple_location (e->call_stmt), + "at-calls % does not support call to %qD", + cdecl); + } + + return result; +} + +/* Return true iff NODE carries the always_inline attribute. */ + +static inline bool +strub_always_inline_p (cgraph_node *node) +{ + return lookup_attribute ("always_inline", DECL_ATTRIBUTES (node->decl)); +} + +/* Return true iff NODE is potentially eligible for any strub-enabled mode, and + optionally REPORT the reasons for ineligibility. */ + +static inline bool +can_strub_p (cgraph_node *node, bool report = false) +{ + bool result = true; + + if (!report && strub_always_inline_p (node)) + return result; + + if (lookup_attribute ("noipa", DECL_ATTRIBUTES (node->decl))) + { + result = false; + + if (!report) + return result; + + sorry_at (DECL_SOURCE_LOCATION (node->decl), + "%qD is not eligible for %" + " because of attribute %", + node->decl); + } + + /* We can't, and don't want to vectorize the watermark and other + strub-introduced parms. */ + if (lookup_attribute ("simd", DECL_ATTRIBUTES (node->decl))) + { + result = false; + + if (!report) + return result; + + sorry_at (DECL_SOURCE_LOCATION (node->decl), + "%qD is not eligible for %" + " because of attribute %", + node->decl); + } + + return result; +} + +/* Return true iff NODE is eligible for at-calls strub, and optionally REPORT + the reasons for ineligibility. Besides general non-eligibility for + strub-enabled modes, at-calls rules out calling builtin apply_args. */ + +static bool +can_strub_at_calls_p (cgraph_node *node, bool report = false) +{ + bool result = !report || can_strub_p (node, report); + + if (!result && !report) + return result; + + return !calls_builtin_apply_args_p (node, report); +} + +/* Symbolic macro for the max number of arguments that internal strub may add to + a function. */ + +#define STRUB_INTERNAL_MAX_EXTRA_ARGS 3 + +/* We can't perform internal strubbing if the function body involves certain + features: + + - a non-default __builtin_va_start (e.g. x86's __builtin_ms_va_start) is + currently unsupported because we can't discover the corresponding va_copy and + va_end decls in the wrapper, and we don't convey the alternate variable + arguments ABI to the modified wrapped function. The default + __builtin_va_start is supported by calling va_start/va_end at the wrapper, + that takes variable arguments, passing a pointer to the va_list object to the + wrapped function, that runs va_copy from it where the original function ran + va_start. + + __builtin_next_arg is currently unsupported because the wrapped function + won't be a variable argument function. We could process it in the wrapper, + that remains a variable argument function, and replace calls in the wrapped + body, but we currently don't. + + __builtin_return_address is rejected because it's generally used when the + actual caller matters, and introducing a wrapper breaks such uses as those in + the unwinder. */ + +static bool +can_strub_internally_p (cgraph_node *node, bool report = false) +{ + bool result = !report || can_strub_p (node, report); + + if (!result && !report) + return result; + + if (!report && strub_always_inline_p (node)) + return result; + + /* Since we're not changing the function identity proper, just + moving its full implementation, we *could* disable + fun->cannot_be_copied_reason and/or temporarily drop a noclone + attribute, but we'd have to prevent remapping of the labels. */ + if (lookup_attribute ("noclone", DECL_ATTRIBUTES (node->decl))) + { + result = false; + + if (!report) + return result; + + sorry_at (DECL_SOURCE_LOCATION (node->decl), + "%qD is not eligible for internal %" + " because of attribute %", + node->decl); + } + + if (node->has_gimple_body_p ()) + { + for (cgraph_edge *e = node->callees; e; e = e->next_callee) + { + tree cdecl = e->callee->decl; + if (!((fndecl_built_in_p (cdecl, BUILT_IN_VA_START) + && cdecl != builtin_decl_explicit (BUILT_IN_VA_START)) + || fndecl_built_in_p (cdecl, BUILT_IN_NEXT_ARG) + || fndecl_built_in_p (cdecl, BUILT_IN_RETURN_ADDRESS))) + continue; + + result = false; + + if (!report) + return result; + + sorry_at (gimple_location (e->call_stmt), + "%qD is not eligible for internal % " + "because it calls %qD", + node->decl, cdecl); + } + + struct function *fun = DECL_STRUCT_FUNCTION (node->decl); + if (fun->has_nonlocal_label) + { + result = false; + + if (!report) + return result; + + sorry_at (DECL_SOURCE_LOCATION (node->decl), + "%qD is not eligible for internal % " + "because it contains a non-local goto target", + node->decl); + } + + if (fun->has_forced_label_in_static) + { + result = false; + + if (!report) + return result; + + sorry_at (DECL_SOURCE_LOCATION (node->decl), + "%qD is not eligible for internal % " + "because the address of a local label escapes", + node->decl); + } + + /* Catch any other case that would prevent versioning/cloning + so as to also have it covered above. */ + gcc_checking_assert (!result /* || !node->has_gimple_body_p () */ + || tree_versionable_function_p (node->decl)); + + + /* Label values references are not preserved when copying. If referenced + in nested functions, as in 920415-1.c and 920721-4.c their decls get + remapped independently. The exclusion below might be too broad, in + that we might be able to support correctly cases in which the labels + are only used internally in a function, but disconnecting forced labels + from their original declarations is undesirable in general. */ + basic_block bb; + FOR_EACH_BB_FN (bb, DECL_STRUCT_FUNCTION (node->decl)) + for (gimple_stmt_iterator gsi = gsi_start_bb (bb); + !gsi_end_p (gsi); gsi_next (&gsi)) + { + glabel *label_stmt = dyn_cast (gsi_stmt (gsi)); + tree target; + + if (!label_stmt) + break; + + target = gimple_label_label (label_stmt); + + if (!FORCED_LABEL (target)) + continue; + + result = false; + + if (!report) + return result; + + sorry_at (gimple_location (label_stmt), + "internal % does not support forced labels"); + } + } + + if (list_length (TYPE_ARG_TYPES (TREE_TYPE (node->decl))) + >= (((HOST_WIDE_INT) 1 << IPA_PARAM_MAX_INDEX_BITS) + - STRUB_INTERNAL_MAX_EXTRA_ARGS)) + { + result = false; + + if (!report) + return result; + + sorry_at (DECL_SOURCE_LOCATION (node->decl), + "%qD has too many arguments for internal %", + node->decl); + } + + return result; +} + +/* Return TRUE iff NODE has any strub-requiring local variable, or accesses (as + in reading) any variable through a strub-requiring type. */ + +static bool +strub_from_body_p (cgraph_node *node) +{ + if (!node->has_gimple_body_p ()) + return false; + + /* If any local variable is marked for strub... */ + unsigned i; + tree var; + FOR_EACH_LOCAL_DECL (DECL_STRUCT_FUNCTION (node->decl), + i, var) + if (get_strub_mode_from_type (TREE_TYPE (var)) + != STRUB_DISABLED) + return true; + + /* Now scan the body for loads with strub-requiring types. + ??? Compound types don't propagate the strub requirement to + component types. */ + basic_block bb; + FOR_EACH_BB_FN (bb, DECL_STRUCT_FUNCTION (node->decl)) + for (gimple_stmt_iterator gsi = gsi_start_bb (bb); + !gsi_end_p (gsi); gsi_next (&gsi)) + { + gimple *stmt = gsi_stmt (gsi); + + if (!gimple_assign_load_p (stmt)) + continue; + + tree rhs = gimple_assign_rhs1 (stmt); + if (get_strub_mode_from_type (TREE_TYPE (rhs)) + != STRUB_DISABLED) + return true; + } + + return false; +} + +/* Return true iff node is associated with a builtin that should be callable + from strub contexts. */ + +static inline bool +strub_callable_builtin_p (cgraph_node *node) +{ + if (DECL_BUILT_IN_CLASS (node->decl) != BUILT_IN_NORMAL) + return false; + + enum built_in_function fcode = DECL_FUNCTION_CODE (node->decl); + + switch (fcode) + { + case BUILT_IN_NONE: + gcc_unreachable (); + + /* This temporarily allocates stack for the call, and we can't reasonably + update the watermark for that. Besides, we don't check the actual call + target, nor its signature, and it seems to be overkill to as much as + try to do so. */ + case BUILT_IN_APPLY: + return false; + + /* Conversely, this shouldn't be called from within strub contexts, since + the caller may have had its signature modified. STRUB_INTERNAL is ok, + the call will remain in the STRUB_WRAPPER, and removed from the + STRUB_WRAPPED clone. */ + case BUILT_IN_APPLY_ARGS: + return false; + + /* ??? Make all other builtins callable. We wish to make any builtin call + the compiler might introduce on its own callable. Anything that is + predictable enough as to be known not to allow stack data that should + be strubbed to unintentionally escape to non-strub contexts can be + allowed, and pretty much every builtin appears to fit this description. + The exceptions to this rule seem to be rare, and only available as + explicit __builtin calls, so let's keep it simple and allow all of + them... */ + default: + return true; + } +} + +/* Compute the strub mode to be used for NODE. STRUB_ATTR should be the strub + attribute,found for NODE, if any. */ + +static enum strub_mode +compute_strub_mode (cgraph_node *node, tree strub_attr) +{ + enum strub_mode req_mode = get_strub_mode_from_attr (strub_attr); + + gcc_checking_assert (flag_strub >= -2 && flag_strub <= 3); + + /* Symbolic encodings of the -fstrub-* flags. */ + /* Enable strub when explicitly requested through attributes to functions or + variables, reporting errors if the requests cannot be satisfied. */ + const bool strub_flag_auto = flag_strub < 0; + /* strub_flag_auto with strub call verification; without this, functions are + implicitly callable. */ + const bool strub_flag_strict = flag_strub < -1; + /* Disable strub altogether, ignore attributes entirely. */ + const bool strub_flag_disabled = flag_strub == 0; + /* On top of _auto, also enable strub implicitly for functions that can + safely undergo at-calls strubbing. Internal mode will still be used in + functions that request it explicitly with attribute strub(2), or when the + function body requires strubbing and at-calls strubbing is not viable. */ + const bool strub_flag_at_calls = flag_strub == 1; + /* On top of default, also enable strub implicitly for functions that can + safely undergo internal strubbing. At-calls mode will still be used in + functions that requiest it explicitly with attribute strub() or strub(1), + or when the function body requires strubbing and internal strubbing is not + viable. */ + const bool strub_flag_internal = flag_strub == 2; + /* On top of default, also enable strub implicitly for functions that can + safely undergo strubbing in either mode. When both modes are viable, + at-calls is preferred. */ + const bool strub_flag_either = flag_strub == 3; + /* Besides the default behavior, enable strub implicitly for all viable + functions. */ + const bool strub_flag_viable = flag_strub > 0; + + /* The consider_* variables should be true if selecting the corresponding + strub modes would be consistent with requests from attributes and command + line flags. Attributes associated with functions pretty much mandate a + selection, and should report an error if not satisfied; strub_flag_auto + implicitly enables some viable strub mode if that's required by references + to variables marked for strub; strub_flag_viable enables strub if viable + (even when favoring one mode, body-requested strub can still be satisfied + by either mode), and falls back to callable, silently unless variables + require strubbing. */ + + const bool consider_at_calls + = (!strub_flag_disabled + && (strub_attr + ? req_mode == STRUB_AT_CALLS + : true)); + const bool consider_internal + = (!strub_flag_disabled + && (strub_attr + ? req_mode == STRUB_INTERNAL + : true)); + + const bool consider_callable + = (!strub_flag_disabled + && (strub_attr + ? req_mode == STRUB_CALLABLE + : (!strub_flag_strict + || strub_callable_builtin_p (node)))); + + /* This is a shorthand for either strub-enabled mode. */ + const bool consider_strub + = (consider_at_calls || consider_internal); + + /* We can cope with always_inline functions even with noipa and noclone, + because we just leave them alone. */ + const bool is_always_inline + = strub_always_inline_p (node); + + /* Strubbing in general, and each specific strub mode, may have its own set of + requirements. We require noipa for strubbing, either because of cloning + required for internal strub, or because of caller enumeration required for + at-calls strub. We don't consider the at-calls mode eligible if it's not + even considered, it has no further requirements. Internal mode requires + cloning and the absence of certain features in the body and, like at-calls, + it's not eligible if it's not even under consideration. + + ??? Do we need target hooks for further constraints? E.g., x86's + "interrupt" attribute breaks internal strubbing because the wrapped clone + carries the attribute and thus isn't callable; in this case, we could use a + target hook to adjust the clone instead. */ + const bool strub_eligible + = (consider_strub + && (is_always_inline || can_strub_p (node))); + const bool at_calls_eligible + = (consider_at_calls && strub_eligible + && can_strub_at_calls_p (node)); + const bool internal_eligible + = (consider_internal && strub_eligible + && (is_always_inline + || can_strub_internally_p (node))); + + /* In addition to the strict eligibility requirements, some additional + constraints are placed on implicit selection of certain modes. These do + not prevent the selection of a mode if explicitly specified as part of a + function interface (the strub attribute), but they may prevent modes from + being selected by the command line or by function bodies. The only actual + constraint is on at-calls mode: since we change the function's exposed + signature, we won't do it implicitly if the function can possibly be used + in ways that do not expect the signature change, e.g., if the function is + available to or interposable by other units, if its address is taken, + etc. */ + const bool at_calls_viable + = (at_calls_eligible + && (strub_attr + || (node->has_gimple_body_p () + && (!node->externally_visible + || (node->binds_to_current_def_p () + && node->can_be_local_p ())) + && node->only_called_directly_p ()))); + const bool internal_viable + = (internal_eligible); + + /* Shorthand. */ + const bool strub_viable + = (at_calls_viable || internal_viable); + + /* We wish to analyze the body, to look for implicit requests for strub, both + to implicitly enable it when the body calls for it, and to report errors if + the body calls for it but neither mode is viable (even if that follows from + non-eligibility because of the explicit specification of some non-strubbing + mode). We can refrain from scanning the body only in rare circumstances: + when strub is enabled by a function attribute (scanning might be redundant + in telling us to also enable it), and when we are enabling strub implicitly + but there are non-viable modes: we want to know whether strubbing is + required, to fallback to another mode, even if we're only enabling a + certain mode, or, when either mode would do, to report an error if neither + happens to be viable. */ + const bool analyze_body + = (strub_attr + ? !consider_strub + : (strub_flag_auto + || (strub_flag_viable && (!at_calls_viable && !internal_viable)) + || (strub_flag_either && !strub_viable))); + + /* Cases in which strubbing is enabled or disabled by strub_flag_auto. + Unsatisfiable requests ought to be reported. */ + const bool strub_required + = ((strub_attr && consider_strub) + || (analyze_body && strub_from_body_p (node))); + + /* Besides the required cases, we want to abide by the requests to enabling on + an if-viable basis. */ + const bool strub_enable + = (strub_required + || (strub_flag_at_calls && at_calls_viable) + || (strub_flag_internal && internal_viable) + || (strub_flag_either && strub_viable)); + + /* And now we're finally ready to select a mode that abides by the viability + and eligibility constraints, and that satisfies the strubbing requirements + and requests, subject to the constraints. If both modes are viable and + strub is to be enabled, pick STRUB_AT_CALLS unless STRUB_INTERNAL was named + as preferred. */ + const enum strub_mode mode + = ((strub_enable && is_always_inline) + ? (strub_required ? STRUB_INLINABLE : STRUB_CALLABLE) + : (strub_enable && internal_viable + && (strub_flag_internal || !at_calls_viable)) + ? STRUB_INTERNAL + : (strub_enable && at_calls_viable) + ? (strub_required && !strub_attr + ? STRUB_AT_CALLS_OPT + : STRUB_AT_CALLS) + : consider_callable + ? STRUB_CALLABLE + : STRUB_DISABLED); + + switch (mode) + { + case STRUB_CALLABLE: + if (is_always_inline) + break; + /* Fall through. */ + + case STRUB_DISABLED: + if (strub_enable && !strub_attr) + { + gcc_checking_assert (analyze_body); + error_at (DECL_SOURCE_LOCATION (node->decl), + "%qD requires %," + " but no viable % mode was found", + node->decl); + break; + } + /* Fall through. */ + + case STRUB_AT_CALLS: + case STRUB_INTERNAL: + case STRUB_INLINABLE: + /* Differences from an mode requested through a function attribute are + reported in set_strub_mode_to. */ + break; + + case STRUB_AT_CALLS_OPT: + /* Functions that select this mode do so because of references to strub + variables. Even if we choose at-calls as an optimization, the + requirements for internal strub must still be satisfied. Optimization + options may render implicit at-calls strub not viable (-O0 sets + force_output for static non-inline functions), and it would not be good + if changing optimization options turned a well-formed into an + ill-formed one. */ + if (!internal_viable) + can_strub_internally_p (node, true); + break; + + case STRUB_WRAPPED: + case STRUB_WRAPPER: + default: + gcc_unreachable (); + } + + return mode; +} + +/* Set FNDT's strub mode to MODE; FNDT may be a function decl or + function type. If OVERRIDE, do not check whether a mode is already + set. */ + +static void +strub_set_fndt_mode_to (tree fndt, enum strub_mode mode, bool override) +{ + gcc_checking_assert (override + || !(DECL_P (fndt) + ? get_strub_attr_from_decl (fndt) + : get_strub_attr_from_type (fndt))); + + tree attr = tree_cons (get_identifier ("strub"), + get_strub_mode_attr_value (mode), + NULL_TREE); + tree *attrp = NULL; + if (DECL_P (fndt)) + { + gcc_checking_assert (FUNC_OR_METHOD_TYPE_P (TREE_TYPE (fndt))); + attrp = &DECL_ATTRIBUTES (fndt); + } + else if (FUNC_OR_METHOD_TYPE_P (fndt)) + attrp = &TYPE_ATTRIBUTES (fndt); + else + gcc_unreachable (); + + TREE_CHAIN (attr) = *attrp; + *attrp = attr; +} + +/* Set FNDT's strub mode to callable. + FNDT may be a function decl or a function type. */ + +void +strub_make_callable (tree fndt) +{ + strub_set_fndt_mode_to (fndt, STRUB_CALLABLE, false); +} + +/* Set NODE to strub MODE. Report incompatibilities between MODE and the mode + requested through explicit attributes, and cases of non-eligibility. */ + +static void +set_strub_mode_to (cgraph_node *node, enum strub_mode mode) +{ + tree attr = get_strub_attr_from_decl (node->decl); + enum strub_mode req_mode = get_strub_mode_from_attr (attr); + + if (attr) + { + /* Check for and report incompatible mode changes. */ + if (mode != req_mode + && !(req_mode == STRUB_INTERNAL + && (mode == STRUB_WRAPPED + || mode == STRUB_WRAPPER)) + && !((req_mode == STRUB_INTERNAL + || req_mode == STRUB_AT_CALLS + || req_mode == STRUB_CALLABLE) + && mode == STRUB_INLINABLE)) + { + error_at (DECL_SOURCE_LOCATION (node->decl), + "% mode %qE selected for %qD, when %qE was requested", + get_strub_mode_attr_parm (mode), + node->decl, + get_strub_mode_attr_parm (req_mode)); + if (node->alias) + { + cgraph_node *target = node->ultimate_alias_target (); + if (target != node) + error_at (DECL_SOURCE_LOCATION (target->decl), + "the incompatible selection was determined" + " by ultimate alias target %qD", + target->decl); + } + + /* Report any incompatibilities with explicitly-requested strub. */ + switch (req_mode) + { + case STRUB_AT_CALLS: + can_strub_at_calls_p (node, true); + break; + + case STRUB_INTERNAL: + can_strub_internally_p (node, true); + break; + + default: + break; + } + } + + /* Drop any incompatible strub attributes leading the decl attribute + chain. Return if we find one with the mode we need. */ + for (;;) + { + if (mode == req_mode) + return; + + if (DECL_ATTRIBUTES (node->decl) != attr) + break; + + DECL_ATTRIBUTES (node->decl) = TREE_CHAIN (attr); + attr = get_strub_attr_from_decl (node->decl); + if (!attr) + break; + + req_mode = get_strub_mode_from_attr (attr); + } + } + else if (mode == req_mode) + return; + + strub_set_fndt_mode_to (node->decl, mode, attr); +} + +/* Compute and set NODE's strub mode. */ + +static void +set_strub_mode (cgraph_node *node) +{ + tree attr = get_strub_attr_from_decl (node->decl); + + if (attr) + switch (get_strub_mode_from_attr (attr)) + { + /* These can't have been requested through user attributes, so we must + have already gone through them. */ + case STRUB_WRAPPER: + case STRUB_WRAPPED: + case STRUB_INLINABLE: + case STRUB_AT_CALLS_OPT: + return; + + case STRUB_DISABLED: + case STRUB_AT_CALLS: + case STRUB_INTERNAL: + case STRUB_CALLABLE: + break; + + default: + gcc_unreachable (); + } + + cgraph_node *xnode = node; + if (node->alias) + xnode = node->ultimate_alias_target (); + /* Weakrefs may remain unresolved (the above will return node) if + their targets are not defined, so make sure we compute a strub + mode for them, instead of defaulting to STRUB_DISABLED and + rendering them uncallable. */ + enum strub_mode mode = (xnode != node && !xnode->alias + ? get_strub_mode (xnode) + : compute_strub_mode (node, attr)); + + set_strub_mode_to (node, mode); +} + + +/* Non-strub functions shouldn't be called from within strub contexts, + except through callable ones. Always inline strub functions can + only be called from strub functions. */ + +static bool +strub_callable_from_p (cgraph_node *callee, cgraph_node *caller) +{ + strub_mode caller_mode = get_strub_mode (caller); + strub_mode callee_mode = get_strub_mode (callee); + + switch (caller_mode) + { + case STRUB_WRAPPED: + case STRUB_AT_CALLS_OPT: + case STRUB_AT_CALLS: + case STRUB_INTERNAL: + case STRUB_INLINABLE: + break; + + case STRUB_WRAPPER: + case STRUB_DISABLED: + case STRUB_CALLABLE: + return callee_mode != STRUB_INLINABLE; + + default: + gcc_unreachable (); + } + + switch (callee_mode) + { + case STRUB_WRAPPED: + case STRUB_AT_CALLS: + case STRUB_INLINABLE: + break; + + case STRUB_AT_CALLS_OPT: + case STRUB_INTERNAL: + case STRUB_WRAPPER: + return (flag_strub >= -1); + + case STRUB_DISABLED: + return false; + + case STRUB_CALLABLE: + break; + + default: + gcc_unreachable (); + } + + return true; +} + +/* Return true if CALLEE can be inlined into CALLER. We wish to avoid inlining + WRAPPED functions back into their WRAPPERs. More generally, we wish to avoid + inlining strubbed functions into non-strubbed ones. CALLER doesn't have to + be an immediate caller of CALLEE: the immediate caller may have already been + cloned for inlining, and then CALLER may be further up the original call + chain. ??? It would be nice if our own caller would retry inlining callee + if caller gets inlined. */ + +bool +strub_inlinable_to_p (cgraph_node *callee, cgraph_node *caller) +{ + strub_mode callee_mode = get_strub_mode (callee); + + switch (callee_mode) + { + case STRUB_WRAPPED: + case STRUB_AT_CALLS: + case STRUB_INTERNAL: + case STRUB_INLINABLE: + case STRUB_AT_CALLS_OPT: + break; + + case STRUB_WRAPPER: + case STRUB_DISABLED: + case STRUB_CALLABLE: + /* When we consider inlining, we've already verified callability, so we + can even inline callable and then disabled into a strub context. That + will get strubbed along with the context, so it's hopefully not a + problem. */ + return true; + + default: + gcc_unreachable (); + } + + strub_mode caller_mode = get_strub_mode (caller); + + switch (caller_mode) + { + case STRUB_WRAPPED: + case STRUB_AT_CALLS: + case STRUB_INTERNAL: + case STRUB_INLINABLE: + case STRUB_AT_CALLS_OPT: + return true; + + case STRUB_WRAPPER: + case STRUB_DISABLED: + case STRUB_CALLABLE: + break; + + default: + gcc_unreachable (); + } + + return false; +} + +/* Check that types T1 and T2 are strub-compatible. Return 1 if the strub modes + are the same, 2 if they are interchangeable, and 0 otherwise. */ + +int +strub_comptypes (tree t1, tree t2) +{ + if (TREE_CODE (t1) != TREE_CODE (t2)) + return 0; + + enum strub_mode m1 = get_strub_mode_from_type (t1); + enum strub_mode m2 = get_strub_mode_from_type (t2); + + if (m1 == m2) + return 1; + + /* We're dealing with types, so only strub modes that can be selected by + attributes in the front end matter. If either mode is at-calls (for + functions) or internal (for variables), the conversion is not + compatible. */ + bool var_p = !FUNC_OR_METHOD_TYPE_P (t1); + enum strub_mode mr = var_p ? STRUB_INTERNAL : STRUB_AT_CALLS; + if (m1 == mr || m2 == mr) + return 0; + + return 2; +} + +/* Check that strub functions don't call non-strub functions, and that + always_inline strub functions are only called by strub + functions. */ + +static void +verify_strub () +{ + cgraph_node *node; + + /* It's expected that check strub-wise pointer type compatibility of variables + and of functions is already taken care of by front-ends, on account of the + attribute's being marked as affecting type identity and of the creation of + distinct types. */ + + /* Check that call targets in strub contexts have strub-callable types. */ + + FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node) + { + enum strub_mode caller_mode = get_strub_mode (node); + bool strub_context + = (caller_mode == STRUB_AT_CALLS + || caller_mode == STRUB_AT_CALLS_OPT + || caller_mode == STRUB_INTERNAL + || caller_mode == STRUB_WRAPPED + || caller_mode == STRUB_INLINABLE); + + for (cgraph_edge *e = node->indirect_calls; e; e = e->next_callee) + { + gcc_checking_assert (e->indirect_unknown_callee); + if (!strub_context) + continue; + + tree callee_fntype = gimple_call_fntype (e->call_stmt); + enum strub_mode callee_mode + = get_strub_mode_from_type (callee_fntype); + + if (callee_mode == STRUB_DISABLED + || callee_mode == STRUB_INTERNAL) + error_at (gimple_location (e->call_stmt), + "indirect non-% call in % context %qD", + node->decl); + } + + for (cgraph_edge *e = node->callees; e; e = e->next_callee) + { + gcc_checking_assert (!e->indirect_unknown_callee); + if (!strub_callable_from_p (e->callee, node)) + { + if (get_strub_mode (e->callee) == STRUB_INLINABLE) + error_at (gimple_location (e->call_stmt), + "calling % % %qD" + " in non-% context %qD", + e->callee->decl, node->decl); + else if (fndecl_built_in_p (e->callee->decl, BUILT_IN_APPLY_ARGS) + && get_strub_mode (node) == STRUB_INTERNAL) + /* This is ok, it will be kept in the STRUB_WRAPPER, and removed + from the STRUB_WRAPPED's strub context. */ + continue; + else + error_at (gimple_location (e->call_stmt), + "calling non-% %qD in % context %qD", + e->callee->decl, node->decl); + } + } + } +} + +namespace { + +/* Define a pass to compute strub modes. */ +const pass_data pass_data_ipa_strub_mode = { + SIMPLE_IPA_PASS, + "strubm", + OPTGROUP_NONE, + TV_NONE, + PROP_cfg, // properties_required + 0, // properties_provided + 0, // properties_destroyed + 0, // properties_start + 0, // properties_finish +}; + +class pass_ipa_strub_mode : public simple_ipa_opt_pass +{ +public: + pass_ipa_strub_mode (gcc::context *ctxt) + : simple_ipa_opt_pass (pass_data_ipa_strub_mode, ctxt) + {} + opt_pass *clone () { return new pass_ipa_strub_mode (m_ctxt); } + virtual bool gate (function *) { + /* In relaxed (-3) and strict (-4) settings, that only enable strub at a + function or variable attribute's request, the attribute handler changes + flag_strub to -1 or -2, respectively, if any strub-enabling occurence of + the attribute is found. Therefore, if it remains at -3 or -4, nothing + that would enable strub was found, so we can disable it and avoid the + overhead. */ + if (flag_strub < -2) + flag_strub = 0; + return flag_strub; + } + virtual unsigned int execute (function *); +}; + +/* Define a pass to introduce strub transformations. */ +const pass_data pass_data_ipa_strub = { + SIMPLE_IPA_PASS, + "strub", + OPTGROUP_NONE, + TV_NONE, + PROP_cfg | PROP_ssa, // properties_required + 0, // properties_provided + 0, // properties_destroyed + 0, // properties_start + TODO_update_ssa + | TODO_cleanup_cfg + | TODO_rebuild_cgraph_edges + | TODO_verify_il, // properties_finish +}; + +class pass_ipa_strub : public simple_ipa_opt_pass +{ +public: + pass_ipa_strub (gcc::context *ctxt) + : simple_ipa_opt_pass (pass_data_ipa_strub, ctxt) + {} + opt_pass *clone () { return new pass_ipa_strub (m_ctxt); } + virtual bool gate (function *) { return flag_strub && !seen_error (); } + virtual unsigned int execute (function *); + + /* Define on demand and cache some types we use often. */ +#define DEF_TYPE(NAME, INIT) \ + static inline tree get_ ## NAME () { \ + static tree type = NULL_TREE; \ + if (!type) \ + type = (INIT); \ + return type; \ + } + + /* Use a distinct ptr_type_node to denote the watermark, so that we can + recognize it in arg lists and avoid modifying types twice. */ + DEF_TYPE (wmt, build_variant_type_copy (ptr_type_node)) + + DEF_TYPE (pwmt, build_reference_type (get_wmt ())) + + DEF_TYPE (qpwmt, + build_qualified_type (get_pwmt (), + TYPE_QUAL_RESTRICT + /* | TYPE_QUAL_CONST */)) + + DEF_TYPE (qptr, + build_qualified_type (ptr_type_node, + TYPE_QUAL_RESTRICT + | TYPE_QUAL_CONST)) + + DEF_TYPE (qpvalst, + build_qualified_type (build_reference_type + (va_list_type_node), + TYPE_QUAL_RESTRICT + /* | TYPE_QUAL_CONST */)) + +#undef DEF_TYPE + + /* Define non-strub builtins on demand. */ +#define DEF_NM_BUILTIN(NAME, CODE, FNTYPELIST) \ + static tree get_ ## NAME () { \ + tree decl = builtin_decl_explicit (CODE); \ + if (!decl) \ + { \ + tree type = build_function_type_list FNTYPELIST; \ + decl = add_builtin_function \ + ("__builtin_" #NAME, \ + type, CODE, BUILT_IN_NORMAL, \ + NULL, NULL); \ + TREE_NOTHROW (decl) = true; \ + set_builtin_decl ((CODE), decl, true); \ + } \ + return decl; \ + } + + DEF_NM_BUILTIN (stack_address, + BUILT_IN_STACK_ADDRESS, + (ptr_type_node, NULL)) + +#undef DEF_NM_BUILTIN + + /* Define strub builtins on demand. */ +#define DEF_SS_BUILTIN(NAME, FNSPEC, CODE, FNTYPELIST) \ + static tree get_ ## NAME () { \ + tree decl = builtin_decl_explicit (CODE); \ + if (!decl) \ + { \ + tree type = build_function_type_list FNTYPELIST; \ + tree attrs = NULL; \ + if (FNSPEC && HAVE_ATTR_FNSPEC) \ + attrs = tree_cons (get_identifier ("fn spec"), \ + build_tree_list \ + (NULL_TREE, \ + build_string (strlen (FNSPEC), \ + (FNSPEC))), \ + attrs); \ + decl = add_builtin_function_ext_scope \ + ("__builtin___strub_" #NAME, \ + type, CODE, BUILT_IN_NORMAL, \ + "__strub_" #NAME, attrs); \ + TREE_NOTHROW (decl) = true; \ + set_builtin_decl ((CODE), decl, true); \ + } \ + return decl; \ + } + + DEF_SS_BUILTIN (enter, ". Ot", + BUILT_IN___STRUB_ENTER, + (void_type_node, get_qpwmt (), NULL)) + DEF_SS_BUILTIN (update, ". Wt", + BUILT_IN___STRUB_UPDATE, + (void_type_node, get_qpwmt (), NULL)) + DEF_SS_BUILTIN (leave, ". w ", + BUILT_IN___STRUB_LEAVE, + (void_type_node, get_qpwmt (), NULL)) + +#undef DEF_SS_BUILTIN + + /* Define strub identifiers on demand. */ +#define DEF_IDENT(NAME) \ + static inline tree get_ ## NAME () { \ + static tree identifier = NULL_TREE; \ + if (!identifier) \ + identifier = get_identifier (".strub." #NAME); \ + return identifier; \ + } + + DEF_IDENT (watermark_ptr) + DEF_IDENT (va_list_ptr) + DEF_IDENT (apply_args) + +#undef DEF_IDENT + + static inline int adjust_at_calls_type (tree); + static inline void adjust_at_calls_call (cgraph_edge *, int); + static inline void adjust_at_calls_calls (cgraph_node *); + + /* Add to SEQ a call to the strub watermark update builtin, taking NODE's + location if given. Optionally add the corresponding edge from NODE, with + execution frequency COUNT. Return the modified SEQ. */ + + static inline gimple_seq + call_update_watermark (tree wmptr, cgraph_node *node, profile_count count, + gimple_seq seq = NULL) + { + tree uwm = get_update (); + gcall *update = gimple_build_call (uwm, 1, wmptr); + if (node) + gimple_set_location (update, DECL_SOURCE_LOCATION (node->decl)); + gimple_seq_add_stmt (&seq, update); + if (node) +#if !IMPLICIT_CGRAPH_EDGES + node->create_edge (cgraph_node::get_create (uwm), update, count, false); +#else + (void)count; +#endif + return seq; + } + +}; + +} // anon namespace + +/* Gather with this type a collection of parameters that we're turning into + explicit references. */ + +typedef hash_set indirect_parms_t; + +/* Dereference OP's incoming turned-into-reference parm if it's an + INDIRECT_PARMS or an ADDR_EXPR thereof. Set *REC and return according to + gimple-walking expectations. */ + +static tree +maybe_make_indirect (indirect_parms_t &indirect_parms, tree op, int *rec) +{ + if (DECL_P (op)) + { + *rec = 0; + if (indirect_parms.contains (op)) + { + tree ret = gimple_fold_indirect_ref (op); + if (!ret) + ret = build2 (MEM_REF, + TREE_TYPE (TREE_TYPE (op)), + op, + build_int_cst (TREE_TYPE (op), 0)); + return ret; + } + } + else if (TREE_CODE (op) == ADDR_EXPR + && DECL_P (TREE_OPERAND (op, 0))) + { + *rec = 0; + if (indirect_parms.contains (TREE_OPERAND (op, 0))) + { + op = TREE_OPERAND (op, 0); + return op; + } + } + + return NULL_TREE; +} + +/* A gimple-walking function that adds dereferencing to indirect parms. */ + +static tree +walk_make_indirect (tree *op, int *rec, void *arg) +{ + walk_stmt_info *wi = (walk_stmt_info *)arg; + indirect_parms_t &indirect_parms = *(indirect_parms_t *)wi->info; + + if (!*op || TYPE_P (*op)) + { + *rec = 0; + return NULL_TREE; + } + + if (tree repl = maybe_make_indirect (indirect_parms, *op, rec)) + { + *op = repl; + wi->changed = true; + } + + return NULL_TREE; +} + +/* A gimple-walking function that turns any non-gimple-val ADDR_EXPRs into a + separate SSA. Though addresses of e.g. parameters, and of members thereof, + are gimple vals, turning parameters into references, with an extra layer of + indirection and thus explicit dereferencing, need to be regimplified. */ + +static tree +walk_regimplify_addr_expr (tree *op, int *rec, void *arg) +{ + walk_stmt_info *wi = (walk_stmt_info *)arg; + gimple_stmt_iterator &gsi = *(gimple_stmt_iterator *)wi->info; + + *rec = 0; + + if (!*op || TREE_CODE (*op) != ADDR_EXPR) + return NULL_TREE; + + if (!is_gimple_val (*op)) + { + tree ret = force_gimple_operand_gsi (&gsi, *op, true, + NULL_TREE, true, GSI_SAME_STMT); + gcc_assert (ret != *op); + *op = ret; + wi->changed = true; + } + + return NULL_TREE; +} + +/* Turn STMT's PHI arg defs into separate SSA defs if they've become + non-gimple_val. Return TRUE if any edge insertions need to be committed. */ + +static bool +walk_regimplify_phi (gphi *stmt) +{ + bool needs_commit = false; + + for (unsigned i = 0, n = gimple_phi_num_args (stmt); i < n; i++) + { + tree op = gimple_phi_arg_def (stmt, i); + if ((TREE_CODE (op) == ADDR_EXPR + && !is_gimple_val (op)) + /* ??? A PARM_DECL that was addressable in the original function and + had its address in PHI nodes, but that became a reference in the + wrapped clone would NOT be updated by update_ssa in PHI nodes. + Alas, if we were to create a default def for it now, update_ssa + would complain that the symbol that needed rewriting already has + SSA names associated with it. OTOH, leaving the PARM_DECL alone, + it eventually causes errors because it remains unchanged in PHI + nodes, but it gets rewritten as expected if it appears in other + stmts. So we cheat a little here, and force the PARM_DECL out of + the PHI node and into an assignment. It's a little expensive, + because we insert it at the edge, which introduces a basic block + that's entirely unnecessary, but it works, and the block will be + removed as the default def gets propagated back into the PHI node, + so the final optimized code looks just as expected. */ + || (TREE_CODE (op) == PARM_DECL + && !TREE_ADDRESSABLE (op))) + { + tree temp = make_ssa_name (TREE_TYPE (op), stmt); + if (TREE_CODE (op) == PARM_DECL) + SET_SSA_NAME_VAR_OR_IDENTIFIER (temp, DECL_NAME (op)); + SET_PHI_ARG_DEF (stmt, i, temp); + + gimple *assign = gimple_build_assign (temp, op); + if (gimple_phi_arg_has_location (stmt, i)) + gimple_set_location (assign, gimple_phi_arg_location (stmt, i)); + gsi_insert_on_edge (gimple_phi_arg_edge (stmt, i), assign); + needs_commit = true; + } + } + + return needs_commit; +} + +/* Create a reference type to use for PARM when turning it into a reference. + NONALIASED causes the reference type to gain its own separate alias set, so + that accessing the indirectly-passed parm won'will not add aliasing + noise. */ + +static tree +build_ref_type_for (tree parm, bool nonaliased = true) +{ + gcc_checking_assert (TREE_CODE (parm) == PARM_DECL); + + tree ref_type = build_reference_type (TREE_TYPE (parm)); + + if (!nonaliased) + return ref_type; + + /* Each PARM turned indirect still points to the distinct memory area at the + wrapper, and the reference in unchanging, so we might qualify it, but... + const is not really important, since we're only using default defs for the + reference parm anyway, and not introducing any defs, and restrict seems to + cause trouble. E.g., libgnat/s-concat3.adb:str_concat_3 has memmoves that, + if it's wrapped, the memmoves are deleted in dse1. Using a distinct alias + set seems to not run afoul of this problem, and it hopefully enables the + compiler to tell the pointers do point to objects that are not otherwise + aliased. */ +#if 1 + tree qref_type = build_variant_type_copy (ref_type); + + TYPE_ALIAS_SET (qref_type) = new_alias_set (); + record_alias_subset (TYPE_ALIAS_SET (qref_type), get_alias_set (ref_type)); + + return qref_type; +#else + tree qref_type = build_qualified_type (ref_type, + TYPE_QUAL_RESTRICT + | TYPE_QUAL_CONST); + + return qref_type; +#endif +} + +/* Add cgraph edges from current_function_decl to callees in SEQ with frequency + COUNT, assuming all calls in SEQ are direct. */ + +static void +add_call_edges_for_seq (gimple_seq seq, profile_count count) +{ +#if IMPLICIT_CGRAPH_EDGES + return; +#endif + + cgraph_node *node = cgraph_node::get_create (current_function_decl); + + for (gimple_stmt_iterator gsi = gsi_start (seq); + !gsi_end_p (gsi); gsi_next (&gsi)) + { + gimple *stmt = gsi_stmt (gsi); + + gcall *call = dyn_cast (stmt); + if (!call) + continue; + + tree callee = gimple_call_fndecl (call); + gcc_checking_assert (callee); + node->create_edge (cgraph_node::get_create (callee), call, count, false); + } +} + +/* Insert SEQ after the call at GSI, as if the call was in a try block with SEQ + as finally, i.e., SEQ will run after the call whether it returns or + propagates an exception. This handles block splitting, EH edge and block + creation, noreturn and nothrow optimizations, and even throwing calls without + preexisting local handlers. */ + +static void +gsi_insert_finally_seq_after_call (gimple_stmt_iterator gsi, gimple_seq seq) +{ + if (!seq) + return; + + gimple *stmt = gsi_stmt (gsi); + + if (gimple_has_location (stmt)) + annotate_all_with_location (seq, gimple_location (stmt)); + + gcall *call = dyn_cast (stmt); + bool noreturn_p = call && gimple_call_noreturn_p (call); + int eh_lp = lookup_stmt_eh_lp (stmt); + bool must_not_throw_p = eh_lp < 0; + bool nothrow_p = (must_not_throw_p + || (call && gimple_call_nothrow_p (call)) + || (eh_lp <= 0 + && (TREE_NOTHROW (cfun->decl) + || !flag_exceptions))); + + if (noreturn_p && nothrow_p) + return; + + /* Don't expect an EH edge if we're not to throw, or if we're not in an EH + region yet. */ + bool no_eh_edge_p = (nothrow_p || !eh_lp); + bool must_end_bb = stmt_ends_bb_p (stmt); + + edge eft = NULL, eeh = NULL; + if (must_end_bb && !(noreturn_p && no_eh_edge_p)) + { + gcc_checking_assert (gsi_one_before_end_p (gsi)); + + edge e; + edge_iterator ei; + FOR_EACH_EDGE (e, ei, gsi_bb (gsi)->succs) + { + if ((e->flags & EDGE_EH)) + { + gcc_checking_assert (!eeh); + eeh = e; +#if !CHECKING_P + if (eft || noreturn_p) + break; +#endif + } + if ((e->flags & EDGE_FALLTHRU)) + { + gcc_checking_assert (!eft); + eft = e; +#if !CHECKING_P + if (eeh || no_eh_edge_p) + break; +#endif + } + } + + gcc_checking_assert (!(eft && (eft->flags & EDGE_FALLTHRU)) + == noreturn_p); + gcc_checking_assert (!(eeh && (eeh->flags & EDGE_EH)) + == no_eh_edge_p); + gcc_checking_assert (eft != eeh); + } + + if (!noreturn_p) + { + gimple_seq nseq = nothrow_p ? seq : gimple_seq_copy (seq); + + if (must_end_bb) + { + gcc_checking_assert (gsi_one_before_end_p (gsi)); + add_call_edges_for_seq (nseq, eft->count ()); + gsi_insert_seq_on_edge_immediate (eft, nseq); + } + else + { + add_call_edges_for_seq (nseq, gsi_bb (gsi)->count); + gsi_insert_seq_after (&gsi, nseq, GSI_SAME_STMT); + } + } + + if (nothrow_p) + return; + + if (eh_lp) + { + add_call_edges_for_seq (seq, eeh->count ()); + gsi_insert_seq_on_edge_immediate (eeh, seq); + return; + } + + /* A throwing call may appear within a basic block in a function that doesn't + have any EH regions. We're going to add a cleanup if so, therefore the + block will have to be split. */ + basic_block bb = gsi_bb (gsi); + if (!gsi_one_before_end_p (gsi)) + split_block (bb, stmt); + + /* Create a new block for the EH cleanup. */ + basic_block bb_eh_cleanup = create_empty_bb (bb); + if (dom_info_available_p (CDI_DOMINATORS)) + set_immediate_dominator (CDI_DOMINATORS, bb_eh_cleanup, bb); + if (current_loops) + add_bb_to_loop (bb_eh_cleanup, current_loops->tree_root); + + /* Make the new block an EH cleanup for the call. */ + eh_region new_r = gen_eh_region_cleanup (NULL); + eh_landing_pad lp = gen_eh_landing_pad (new_r); + tree label = gimple_block_label (bb_eh_cleanup); + lp->post_landing_pad = label; + EH_LANDING_PAD_NR (label) = lp->index; + add_stmt_to_eh_lp (stmt, lp->index); + + /* Add the cleanup code to the EH cleanup block. */ + gsi = gsi_after_labels (bb_eh_cleanup); + gsi_insert_seq_before (&gsi, seq, GSI_SAME_STMT); + + /* And then propagate the exception further. */ + gresx *resx = gimple_build_resx (new_r->index); + if (gimple_has_location (stmt)) + gimple_set_location (resx, gimple_location (stmt)); + gsi_insert_before (&gsi, resx, GSI_SAME_STMT); + + /* Finally, wire the EH cleanup block into the CFG. */ + make_eh_edges (stmt); + add_call_edges_for_seq (seq, single_pred_edge (bb_eh_cleanup)->count ()); +} + +/* Copy the attribute list at *ATTRS, minus any NAME attributes, leaving + shareable trailing nodes alone. */ + +static inline void +remove_named_attribute_unsharing (const char *name, tree *attrs) +{ + while (tree found = lookup_attribute (name, *attrs)) + { + /* Copy nodes up to the next NAME attribute. */ + while (*attrs != found) + { + *attrs = tree_cons (TREE_PURPOSE (*attrs), + TREE_VALUE (*attrs), + TREE_CHAIN (*attrs)); + attrs = &TREE_CHAIN (*attrs); + } + /* Then drop it. */ + gcc_checking_assert (*attrs == found); + *attrs = TREE_CHAIN (*attrs); + } +} + +/* Record the order of the last cgraph entry whose mode we've already set, so + that we can perform mode setting incrementally without duplication. */ +static int last_cgraph_order; + +/* Set strub modes for functions introduced since the last call. */ + +static void +ipa_strub_set_mode_for_new_functions () +{ + if (symtab->order == last_cgraph_order) + return; + + cgraph_node *node; + + /* Go through the functions twice, once over non-aliases, and then over + aliases, so that aliases can reuse the mode computation of their ultimate + targets. */ + for (int aliases = 0; aliases <= 1; aliases++) + FOR_EACH_FUNCTION (node) + { + if (!node->alias != !aliases) + continue; + + /* Already done. */ + if (node->order < last_cgraph_order) + continue; + + set_strub_mode (node); + } + + last_cgraph_order = symtab->order; +} + +/* Return FALSE if NODE is a strub context, and TRUE otherwise. */ + +bool +strub_splittable_p (cgraph_node *node) +{ + switch (get_strub_mode (node)) + { + case STRUB_WRAPPED: + case STRUB_AT_CALLS: + case STRUB_AT_CALLS_OPT: + case STRUB_INLINABLE: + case STRUB_INTERNAL: + case STRUB_WRAPPER: + return false; + + case STRUB_CALLABLE: + case STRUB_DISABLED: + break; + + default: + gcc_unreachable (); + } + + return true; +} + +/* Return the PARM_DECL of the incoming watermark pointer, if there is one. */ + +tree +strub_watermark_parm (tree fndecl) +{ + switch (get_strub_mode_from_fndecl (fndecl)) + { + case STRUB_WRAPPED: + case STRUB_AT_CALLS: + case STRUB_AT_CALLS_OPT: + break; + + case STRUB_INTERNAL: + case STRUB_WRAPPER: + case STRUB_CALLABLE: + case STRUB_DISABLED: + case STRUB_INLINABLE: + return NULL_TREE; + + default: + gcc_unreachable (); + } + + for (tree parm = DECL_ARGUMENTS (fndecl); parm; parm = DECL_CHAIN (parm)) + /* The type (variant) compare finds the parameter even in a just-created + clone, before we set its name, but the type-based compare doesn't work + during builtin expansion within the lto compiler, because we'll have + created a separate variant in that run. */ + if (TREE_TYPE (parm) == pass_ipa_strub::get_qpwmt () + || DECL_NAME (parm) == pass_ipa_strub::get_watermark_ptr ()) + return parm; + + gcc_unreachable (); +} + +/* Adjust a STRUB_AT_CALLS function TYPE, adding a watermark pointer if it + hasn't been added yet. Return the named argument count. */ + +int +pass_ipa_strub::adjust_at_calls_type (tree type) +{ + int named_args = 0; + + if (!TYPE_ARG_TYPES (type)) + return named_args; + + tree *tlist = &TYPE_ARG_TYPES (type); + tree qpwmptrt = get_qpwmt (); + while (*tlist && TREE_VALUE (*tlist) != void_type_node) + { + /* The type has already been adjusted. */ + if (TREE_VALUE (*tlist) == qpwmptrt) + return named_args; + named_args++; + *tlist = tree_cons (TREE_PURPOSE (*tlist), + TREE_VALUE (*tlist), + TREE_CHAIN (*tlist)); + tlist = &TREE_CHAIN (*tlist); + } + + /* Add the new argument after all named arguments, so as to not mess with + attributes that reference parameters. */ + *tlist = tree_cons (NULL_TREE, get_qpwmt (), *tlist); + +#if ATTR_FNSPEC_DECONST_WATERMARK + if (!type_already_adjusted) + { + int flags = flags_from_decl_or_type (type); + tree fnspec = lookup_attribute ("fn spec", type); + + if ((flags & (ECF_CONST | ECF_PURE | ECF_NOVOPS)) || fnspec) + { + size_t xargs = 1; + size_t curlen = 0, tgtlen = 2 + 2 * (named_args + xargs); + auto_vec nspecv (tgtlen); + char *nspec = &nspecv[0]; /* It will *not* be NUL-terminated! */ + if (fnspec) + { + tree fnspecstr = TREE_VALUE (TREE_VALUE (fnspec)); + curlen = TREE_STRING_LENGTH (fnspecstr); + memcpy (nspec, TREE_STRING_POINTER (fnspecstr), curlen); + } + if (!curlen) + { + nspec[curlen++] = '.'; + nspec[curlen++] = ((flags & ECF_CONST) + ? 'c' + : (flags & ECF_PURE) + ? 'p' + : ' '); + } + while (curlen < tgtlen - 2 * xargs) + { + nspec[curlen++] = '.'; + nspec[curlen++] = ' '; + } + nspec[curlen++] = 'W'; + nspec[curlen++] = 't'; + + /* The type has already been copied, if needed, before adding + parameters. */ + TYPE_ATTRIBUTES (type) + = tree_cons (get_identifier ("fn spec"), + build_tree_list (NULL_TREE, + build_string (tgtlen, nspec)), + TYPE_ATTRIBUTES (type)); + } + } +#endif + + return named_args; +} + +/* Adjust a call to an at-calls call target. Create a watermark local variable + if needed, initialize it before, pass it to the callee according to the + modified at-calls interface, and release the callee's stack space after the + call, if not deferred. If the call is const or pure, arrange for the + watermark to not be assumed unused or unchanged. */ + +void +pass_ipa_strub::adjust_at_calls_call (cgraph_edge *e, int named_args) +{ + gcall *ocall = e->call_stmt; + gimple_stmt_iterator gsi = gsi_for_stmt (ocall); + + /* Make sure we haven't modified this call yet. */ + gcc_checking_assert (!(int (gimple_call_num_args (ocall)) > named_args + && (TREE_TYPE (gimple_call_arg (ocall, named_args)) + == get_pwmt ()))); + + /* If we're already within a strub context, pass on the incoming watermark + pointer, and omit the enter and leave calls around the modified call, as an + optimization, or as a means to satisfy a tail-call requirement. */ + tree swmp = ((optimize_size || optimize > 2 + || gimple_call_must_tail_p (ocall) + || (optimize == 2 && gimple_call_tail_p (ocall))) + ? strub_watermark_parm (e->caller->decl) + : NULL_TREE); + bool omit_own_watermark = swmp; + tree swm = NULL_TREE; + if (!omit_own_watermark) + { + swm = create_tmp_var (get_wmt (), ".strub.watermark"); + TREE_ADDRESSABLE (swm) = true; + swmp = build1 (ADDR_EXPR, get_pwmt (), swm); + + /* Initialize the watermark before the call. */ + tree enter = get_enter (); + gcall *stptr = gimple_build_call (enter, 1, + unshare_expr (swmp)); + if (gimple_has_location (ocall)) + gimple_set_location (stptr, gimple_location (ocall)); + gsi_insert_before (&gsi, stptr, GSI_SAME_STMT); +#if !IMPLICIT_CGRAPH_EDGES + e->caller->create_edge (cgraph_node::get_create (enter), + stptr, gsi_bb (gsi)->count, false); +#endif + } + + + /* Replace the call with one that passes the swmp argument first. */ + gcall *wrcall; + { gcall *stmt = ocall; + // Mostly copied from gimple_call_copy_skip_args. + int i = 0; + int nargs = gimple_call_num_args (stmt); + auto_vec vargs (MAX (nargs, named_args) + 1); + gcall *new_stmt; + + /* pr71109.c calls a prototypeless function, then defines it with + additional arguments. It's ill-formed, but after it's inlined, + it somehow works out. */ + for (; i < named_args && i < nargs; i++) + vargs.quick_push (gimple_call_arg (stmt, i)); + for (; i < named_args; i++) + vargs.quick_push (null_pointer_node); + + vargs.quick_push (unshare_expr (swmp)); + + for (; i < nargs; i++) +#if 0 + if (!bitmap_bit_p (args_to_skip, i)) +#endif + vargs.quick_push (gimple_call_arg (stmt, i)); + + if (gimple_call_internal_p (stmt)) +#if 0 + new_stmt = gimple_build_call_internal_vec (gimple_call_internal_fn (stmt), + vargs); +#endif + gcc_unreachable (); + else + new_stmt = gimple_build_call_vec (gimple_call_fn (stmt), vargs); + + if (gimple_call_lhs (stmt)) + gimple_call_set_lhs (new_stmt, gimple_call_lhs (stmt)); + +#if 0 + gimple_set_vuse (new_stmt, gimple_vuse (stmt)); + gimple_set_vdef (new_stmt, gimple_vdef (stmt)); +#else + gimple_move_vops (new_stmt, stmt); +#endif + + if (gimple_has_location (stmt)) + gimple_set_location (new_stmt, gimple_location (stmt)); + gimple_call_copy_flags (new_stmt, stmt); + gimple_call_set_chain (new_stmt, gimple_call_chain (stmt)); + + gimple_set_modified (new_stmt, true); + + wrcall = new_stmt; + } + + update_stmt (wrcall); + gsi_replace (&gsi, wrcall, true); + cgraph_edge::set_call_stmt (e, wrcall, false); + + /* Insert the strub code after the call. */ + gimple_seq seq = NULL; + +#if !ATTR_FNSPEC_DECONST_WATERMARK + /* If the call will be assumed to not modify or even read the + watermark, make it read and modified ourselves. */ + if ((gimple_call_flags (wrcall) + & (ECF_CONST | ECF_PURE | ECF_NOVOPS))) + { + if (!swm) + swm = build2 (MEM_REF, + TREE_TYPE (TREE_TYPE (swmp)), + swmp, + build_int_cst (TREE_TYPE (swmp), 0)); + + vec *inputs = NULL; + vec *outputs = NULL; + vec_safe_push (outputs, + build_tree_list + (build_tree_list + (NULL_TREE, build_string (2, "=m")), + unshare_expr (swm))); + vec_safe_push (inputs, + build_tree_list + (build_tree_list + (NULL_TREE, build_string (1, "m")), + unshare_expr (swm))); + gasm *forcemod = gimple_build_asm_vec ("", inputs, outputs, + NULL, NULL); + gimple_seq_add_stmt (&seq, forcemod); + + /* If the call will be assumed to not even read the watermark, + make sure it is already in memory before the call. */ + if ((gimple_call_flags (wrcall) & ECF_CONST)) + { + vec *inputs = NULL; + vec_safe_push (inputs, + build_tree_list + (build_tree_list + (NULL_TREE, build_string (1, "m")), + unshare_expr (swm))); + gasm *force_store = gimple_build_asm_vec ("", inputs, NULL, + NULL, NULL); + if (gimple_has_location (wrcall)) + gimple_set_location (force_store, gimple_location (wrcall)); + gsi_insert_before (&gsi, force_store, GSI_SAME_STMT); + } + } +#endif + + if (!omit_own_watermark) + { + gcall *sleave = gimple_build_call (get_leave (), 1, + unshare_expr (swmp)); + gimple_seq_add_stmt (&seq, sleave); + + gassign *clobber = gimple_build_assign (swm, + build_clobber + (TREE_TYPE (swm))); + gimple_seq_add_stmt (&seq, clobber); + } + + gsi_insert_finally_seq_after_call (gsi, seq); +} + +/* Adjust all at-calls calls in NODE. */ + +void +pass_ipa_strub::adjust_at_calls_calls (cgraph_node *node) +{ + /* Adjust unknown-callee indirect calls with STRUB_AT_CALLS types within + onode. */ + if (node->indirect_calls) + { + push_cfun (DECL_STRUCT_FUNCTION (node->decl)); + for (cgraph_edge *e = node->indirect_calls; e; e = e->next_callee) + { + gcc_checking_assert (e->indirect_unknown_callee); + + tree callee_fntype = gimple_call_fntype (e->call_stmt); + enum strub_mode callee_mode + = get_strub_mode_from_type (callee_fntype); + + if (callee_mode != STRUB_AT_CALLS + && callee_mode != STRUB_AT_CALLS_OPT) + continue; + + int named_args = adjust_at_calls_type (callee_fntype); + + adjust_at_calls_call (e, named_args); + } + pop_cfun (); + } + + if (node->callees) + { + push_cfun (DECL_STRUCT_FUNCTION (node->decl)); + for (cgraph_edge *e = node->callees; e; e = e->next_callee) + { + gcc_checking_assert (!e->indirect_unknown_callee); + + enum strub_mode callee_mode = get_strub_mode (e->callee); + + if (callee_mode != STRUB_AT_CALLS + && callee_mode != STRUB_AT_CALLS_OPT) + continue; + + int named_args = adjust_at_calls_type (TREE_TYPE (e->callee->decl)); + + adjust_at_calls_call (e, named_args); + } + pop_cfun (); + } +} + +/* The strubm (strub mode) pass computes a strub mode for each function in the + call graph, and checks, before any inlining, that strub callability + requirements in effect are satisfied. */ + +unsigned int +pass_ipa_strub_mode::execute (function *) +{ + last_cgraph_order = 0; + ipa_strub_set_mode_for_new_functions (); + + /* Verify before any inlining or other transformations. */ + verify_strub (); + + return 0; +} + +/* Create a strub mode pass. */ + +simple_ipa_opt_pass * +make_pass_ipa_strub_mode (gcc::context *ctxt) +{ + return new pass_ipa_strub_mode (ctxt); +} + +/* The strub pass proper adjusts types, signatures, and at-calls calls, and + splits internal-strub functions. */ + +unsigned int +pass_ipa_strub::execute (function *) +{ + cgraph_node *onode; + + ipa_strub_set_mode_for_new_functions (); + + /* First, adjust the signature of at-calls functions. We adjust types of + at-calls functions first, so that we don't modify types in place unless + strub is explicitly requested. */ + FOR_EACH_FUNCTION (onode) + { + enum strub_mode mode = get_strub_mode (onode); + + if (mode == STRUB_AT_CALLS + || mode == STRUB_AT_CALLS_OPT) + { + /* Create a type variant if strubbing was not explicitly requested in + the function type. */ + if (get_strub_mode_from_type (TREE_TYPE (onode->decl)) != mode) + TREE_TYPE (onode->decl) = build_distinct_type_copy (TREE_TYPE + (onode->decl)); + + int named_args = adjust_at_calls_type (TREE_TYPE (onode->decl)); + + /* An external function explicitly declared with strub won't have a + body. Even with implicit at-calls strub, a function may have had its + body removed after we selected the mode, and then we have nothing + further to do. */ + if (!onode->has_gimple_body_p ()) + continue; + + tree *pargs = &DECL_ARGUMENTS (onode->decl); + + /* A noninterposable_alias reuses the same parm decl chain, don't add + the parm twice. */ + bool aliased_parms = (onode->alias && *pargs + && DECL_CONTEXT (*pargs) != onode->decl); + + if (aliased_parms) + continue; + + for (int i = 0; i < named_args; i++) + pargs = &DECL_CHAIN (*pargs); + + tree wmptr = build_decl (DECL_SOURCE_LOCATION (onode->decl), + PARM_DECL, + get_watermark_ptr (), + get_qpwmt ()); + DECL_ARTIFICIAL (wmptr) = 1; + DECL_ARG_TYPE (wmptr) = get_qpwmt (); + DECL_CONTEXT (wmptr) = onode->decl; + TREE_USED (wmptr) = 1; + DECL_CHAIN (wmptr) = *pargs; + *pargs = wmptr; + + if (onode->alias) + continue; + + cgraph_node *nnode = onode; + push_cfun (DECL_STRUCT_FUNCTION (nnode->decl)); + + { + edge e = single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun)); + gimple_seq seq = call_update_watermark (wmptr, nnode, e->src->count); + gsi_insert_seq_on_edge_immediate (e, seq); + } + + if (DECL_STRUCT_FUNCTION (nnode->decl)->calls_alloca) + { + basic_block bb; + FOR_EACH_BB_FN (bb, cfun) + for (gimple_stmt_iterator gsi = gsi_start_bb (bb); + !gsi_end_p (gsi); gsi_next (&gsi)) + { + gimple *stmt = gsi_stmt (gsi); + + gcall *call = dyn_cast (stmt); + + if (!call) + continue; + + if (gimple_alloca_call_p (call)) + { + /* Capture stack growth. */ + gimple_seq seq = call_update_watermark (wmptr, NULL, + gsi_bb (gsi) + ->count); + gsi_insert_finally_seq_after_call (gsi, seq); + } + } + } + + pop_cfun (); + } + } + + FOR_EACH_FUNCTION (onode) + { + if (!onode->has_gimple_body_p ()) + continue; + + enum strub_mode mode = get_strub_mode (onode); + + if (mode != STRUB_INTERNAL) + { + adjust_at_calls_calls (onode); + continue; + } + + bool is_stdarg = calls_builtin_va_start_p (onode);; + bool apply_args = calls_builtin_apply_args_p (onode); + + vec *nparms = NULL; + unsigned j = 0; + { + // The following loop copied from ipa-split.c:split_function. + for (tree parm = DECL_ARGUMENTS (onode->decl); + parm; parm = DECL_CHAIN (parm), j++) + { + ipa_adjusted_param adj = {}; + adj.op = IPA_PARAM_OP_COPY; + adj.base_index = j; + adj.prev_clone_index = j; + vec_safe_push (nparms, adj); + } + + if (apply_args) + { + ipa_adjusted_param aaadj = {}; + aaadj.op = IPA_PARAM_OP_NEW; + aaadj.type = get_qptr (); + vec_safe_push (nparms, aaadj); + } + + if (is_stdarg) + { + ipa_adjusted_param vladj = {}; + vladj.op = IPA_PARAM_OP_NEW; + vladj.type = get_qpvalst (); + vec_safe_push (nparms, vladj); + } + + ipa_adjusted_param wmadj = {}; + wmadj.op = IPA_PARAM_OP_NEW; + wmadj.type = get_qpwmt (); + vec_safe_push (nparms, wmadj); + } + ipa_param_adjustments adj (nparms, -1, false); + + cgraph_node *nnode = onode->create_version_clone_with_body + (auto_vec (0), + NULL, &adj, NULL, NULL, "strub", NULL); + + if (!nnode) + { + error_at (DECL_SOURCE_LOCATION (onode->decl), + "failed to split %qD for %", + onode->decl); + continue; + } + + onode->split_part = true; + if (onode->calls_comdat_local) + nnode->add_to_same_comdat_group (onode); + + gcc_checking_assert (!DECL_STRUCT_FUNCTION (nnode->decl)->stdarg); + + set_strub_mode_to (onode, STRUB_WRAPPER); + set_strub_mode_to (nnode, STRUB_WRAPPED); + + adjust_at_calls_calls (nnode); + + /* Decide which of the wrapped function's parms we want to turn into + references to the argument passed to the wrapper. In general, we want to + copy small arguments, and avoid copying large ones. Variable-sized array + lengths given by other arguments, as in 20020210-1.c, would lead to + problems if passed by value, after resetting the original function and + dropping the length computation; passing them by reference works. + DECL_BY_REFERENCE is *not* a substitute for this: it involves copying + anyway, but performed at the caller. */ + indirect_parms_t indirect_nparms (3, false); + unsigned adjust_ftype = 0; + unsigned named_args = 0; + for (tree parm = DECL_ARGUMENTS (onode->decl), + nparm = DECL_ARGUMENTS (nnode->decl), + nparmt = TYPE_ARG_TYPES (TREE_TYPE (nnode->decl)); + parm; + named_args++, + parm = DECL_CHAIN (parm), + nparm = DECL_CHAIN (nparm), + nparmt = nparmt ? TREE_CHAIN (nparmt) : NULL_TREE) + if (!(0 /* DECL_BY_REFERENCE (narg) */ + || is_gimple_reg_type (TREE_TYPE (nparm)) + || VECTOR_TYPE_P (TREE_TYPE (nparm)) + || TREE_CODE (TREE_TYPE (nparm)) == COMPLEX_TYPE + || (tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (nparm))) + && (tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (nparm))) + <= 4 * UNITS_PER_WORD)))) + { + indirect_nparms.add (nparm); + + /* ??? Is there any case in which it is not safe to suggest the parms + turned indirect don't alias anything else? They are distinct, + unaliased memory in the wrapper, and the wrapped can't possibly + take pointers into them because none of the pointers passed to the + wrapper can alias other incoming parameters passed by value, even + if with transparent reference, and the wrapper doesn't take any + extra parms that could point into wrapper's parms. So we can + probably drop the TREE_ADDRESSABLE and keep the true. */ + tree ref_type = build_ref_type_for (nparm, + true + || !TREE_ADDRESSABLE (parm)); + + DECL_ARG_TYPE (nparm) = TREE_TYPE (nparm) = ref_type; + relayout_decl (nparm); + TREE_ADDRESSABLE (nparm) = 0; + DECL_BY_REFERENCE (nparm) = 0; +#if FOR_GCC_11P + DECL_NOT_GIMPLE_REG_P (nparm) = 0; +#else + DECL_GIMPLE_REG_P (nparm) = 1; +#endif + /* ??? This avoids mismatches in debug info bind stmts in + e.g. a-chahan . */ + DECL_ABSTRACT_ORIGIN (nparm) = NULL; + + if (nparmt) + adjust_ftype++; + } + + /* Also adjust the wrapped function type, if needed. */ + if (adjust_ftype) + { + tree nftype = TREE_TYPE (nnode->decl); + + /* We always add at least one argument at the end of the signature, when + cloning the function, so we don't expect to need to duplicate the + type here. */ + gcc_checking_assert (TYPE_ARG_TYPES (nftype) + != TYPE_ARG_TYPES (TREE_TYPE (onode->decl))); + +#if HAVE_ATTR_FNSPEC + /* Check that fnspec still works for the modified function signature, + and drop it otherwise. */ + bool drop_fnspec = false; + tree fnspec = lookup_attribute ("fn spec", TYPE_ATTRIBUTES (nftype)); + attr_fnspec spec = fnspec ? attr_fnspec (fnspec) : attr_fnspec (""); + + unsigned retcopy; + if (!(fnspec && spec.returns_arg (&retcopy))) + retcopy = (unsigned) -1; + + unsigned i = 0; +#endif + for (tree nparm = DECL_ARGUMENTS (nnode->decl), + nparmt = TYPE_ARG_TYPES (nftype); + adjust_ftype > 0; +#if HAVE_ATTR_FNSPEC + i++, +#endif + nparm = DECL_CHAIN (nparm), nparmt = TREE_CHAIN (nparmt)) + if (indirect_nparms.contains (nparm)) + { + TREE_VALUE (nparmt) = TREE_TYPE (nparm); + adjust_ftype--; + +#if HAVE_ATTR_FNSPEC + if (fnspec && !drop_fnspec) + { + if (i == retcopy) + drop_fnspec = true; + else if (spec.arg_specified_p (i)) + { + /* Properties that apply to pointers only must not be + present, because we don't make pointers further + indirect. */ + gcc_checking_assert + (!spec.arg_max_access_size_given_by_arg_p (i, NULL)); + gcc_checking_assert (!spec.arg_copied_to_arg_p (i, NULL)); + + /* Any claim of direct access only is invalidated by + adding an indirection level. */ + if (spec.arg_direct_p (i)) + drop_fnspec = true; + + /* If there's a claim the argument is not read from, the + added indirection invalidates it: if the argument is + used at all, then the pointer will necessarily be + read. */ + if (!spec.arg_maybe_read_p (i) + && spec.arg_used_p (i)) + drop_fnspec = true; + } + } +#endif + } + +#if HAVE_ATTR_FNSPEC + /* ??? Maybe we could adjust it instead. */ + if (drop_fnspec) + remove_named_attribute_unsharing ("fn spec", + &TYPE_ATTRIBUTES (nftype)); +#endif + + TREE_TYPE (nnode->decl) = nftype; + } + +#if ATTR_FNSPEC_DECONST_WATERMARK + { + int flags = flags_from_decl_or_type (nnode->decl); + tree fnspec = lookup_attribute ("fn spec", TREE_TYPE (nnode->decl)); + + if ((flags & (ECF_CONST | ECF_PURE | ECF_NOVOPS)) || fnspec) + { + size_t xargs = 1 + int (is_stdarg) + int (apply_args); + size_t curlen = 0, tgtlen = 2 + 2 * (named_args + xargs); + auto_vec nspecv (tgtlen); + char *nspec = &nspecv[0]; /* It will *not* be NUL-terminated! */ + bool no_writes_p = true; + if (fnspec) + { + tree fnspecstr = TREE_VALUE (TREE_VALUE (fnspec)); + curlen = TREE_STRING_LENGTH (fnspecstr); + memcpy (nspec, TREE_STRING_POINTER (fnspecstr), curlen); + if (!(flags & (ECF_CONST | ECF_PURE | ECF_NOVOPS)) + && curlen >= 2 + && nspec[1] != 'c' && nspec[1] != 'C' + && nspec[1] != 'p' && nspec[1] != 'P') + no_writes_p = false; + } + if (!curlen) + { + nspec[curlen++] = '.'; + nspec[curlen++] = ((flags & ECF_CONST) + ? 'c' + : (flags & ECF_PURE) + ? 'p' + : ' '); + } + while (curlen < tgtlen - 2 * xargs) + { + nspec[curlen++] = '.'; + nspec[curlen++] = ' '; + } + + /* These extra args are unlikely to be present in const or pure + functions. It's conceivable that a function that takes variable + arguments, or that passes its arguments on to another function, + could be const or pure, but it would not modify the arguments, and, + being pure or const, it couldn't possibly modify or even access + memory referenced by them. But it can read from these internal + data structures created by the wrapper, and from any + argument-passing memory referenced by them, so we denote the + possibility of reading from multiple levels of indirection, but + only of reading because const/pure. */ + if (apply_args) + { + nspec[curlen++] = 'r'; + nspec[curlen++] = ' '; + } + if (is_stdarg) + { + nspec[curlen++] = (no_writes_p ? 'r' : '.'); + nspec[curlen++] = (no_writes_p ? 't' : ' '); + } + + nspec[curlen++] = 'W'; + nspec[curlen++] = 't'; + + /* The type has already been copied before adding parameters. */ + gcc_checking_assert (TYPE_ARG_TYPES (TREE_TYPE (nnode->decl)) + != TYPE_ARG_TYPES (TREE_TYPE (onode->decl))); + TYPE_ATTRIBUTES (TREE_TYPE (nnode->decl)) + = tree_cons (get_identifier ("fn spec"), + build_tree_list (NULL_TREE, + build_string (tgtlen, nspec)), + TYPE_ATTRIBUTES (TREE_TYPE (nnode->decl))); + } + } +#endif + + { + tree decl = onode->decl; + cgraph_node *target = nnode; + + { // copied from create_wrapper + + /* Preserve DECL_RESULT so we get right by reference flag. */ + tree decl_result = DECL_RESULT (decl); + + /* Remove the function's body but keep arguments to be reused + for thunk. */ + onode->release_body (true); + onode->reset (); + + DECL_UNINLINABLE (decl) = false; + DECL_RESULT (decl) = decl_result; + DECL_INITIAL (decl) = NULL; + allocate_struct_function (decl, false); + set_cfun (NULL); + + /* Turn alias into thunk and expand it into GIMPLE representation. */ + onode->definition = true; + +#if FOR_GCC_11P + thunk_info::get_create (onode); + onode->thunk = true; +#else + memset (&onode->thunk, 0, sizeof (cgraph_thunk_info)); + onode->thunk.thunk_p = true; + onode->thunk.alias = target->decl; +#endif +#if !IMPLICIT_CGRAPH_EDGES + onode->create_edge (target, NULL, onode->count); +#endif + onode->callees->can_throw_external = !TREE_NOTHROW (target->decl); + + tree arguments = DECL_ARGUMENTS (decl); + + while (arguments) + { + TREE_ADDRESSABLE (arguments) = false; + arguments = TREE_CHAIN (arguments); + } + + { + tree alias = onode->callees->callee->decl; + tree thunk_fndecl = decl; + tree a; + + int nxargs = 1 + is_stdarg + apply_args; + + { // Simplified from expand_thunk. + tree restype; + basic_block bb, then_bb, else_bb, return_bb; + gimple_stmt_iterator bsi; + int nargs = 0; + tree arg; + int i; + tree resdecl; + tree restmp = NULL; + + gcall *call; + greturn *ret; + bool alias_is_noreturn = TREE_THIS_VOLATILE (alias); + + a = DECL_ARGUMENTS (thunk_fndecl); + + current_function_decl = thunk_fndecl; + +#if FOR_GCC_11P + /* Ensure thunks are emitted in their correct sections. */ + resolve_unique_section (thunk_fndecl, 0, + flag_function_sections); +#endif + + bitmap_obstack_initialize (NULL); + + /* Build the return declaration for the function. */ + restype = TREE_TYPE (TREE_TYPE (thunk_fndecl)); + if (DECL_RESULT (thunk_fndecl) == NULL_TREE) + { + resdecl = build_decl (input_location, RESULT_DECL, 0, restype); + DECL_ARTIFICIAL (resdecl) = 1; + DECL_IGNORED_P (resdecl) = 1; + DECL_CONTEXT (resdecl) = thunk_fndecl; + DECL_RESULT (thunk_fndecl) = resdecl; + } + else + resdecl = DECL_RESULT (thunk_fndecl); + + profile_count cfg_count = onode->count; + if (!cfg_count.initialized_p ()) + cfg_count = profile_count::from_gcov_type (BB_FREQ_MAX).guessed_local (); + + bb = then_bb = else_bb = return_bb + = init_lowered_empty_function (thunk_fndecl, true, cfg_count); + + bsi = gsi_start_bb (bb); + + /* Build call to the function being thunked. */ + if (!VOID_TYPE_P (restype) + && (!alias_is_noreturn + || TREE_ADDRESSABLE (restype) + || TREE_CODE (TYPE_SIZE_UNIT (restype)) != INTEGER_CST)) + { + if (DECL_BY_REFERENCE (resdecl)) + { + restmp = gimple_fold_indirect_ref (resdecl); + if (!restmp) + restmp = build2 (MEM_REF, + TREE_TYPE (TREE_TYPE (resdecl)), + resdecl, + build_int_cst (TREE_TYPE (resdecl), 0)); + } + else if (!is_gimple_reg_type (restype)) + { + if (aggregate_value_p (resdecl, TREE_TYPE (thunk_fndecl))) + { + restmp = resdecl; + + if (VAR_P (restmp)) + { + add_local_decl (cfun, restmp); + BLOCK_VARS (DECL_INITIAL (current_function_decl)) + = restmp; + } + } + else + restmp = create_tmp_var (restype, "retval"); + } + else + restmp = create_tmp_reg (restype, "retval"); + } + + for (arg = a; arg; arg = DECL_CHAIN (arg)) + nargs++; + auto_vec vargs (nargs + nxargs); + i = 0; + arg = a; + + if (nargs) + for (tree nparm = DECL_ARGUMENTS (nnode->decl); + i < nargs; + i++, arg = DECL_CHAIN (arg), nparm = DECL_CHAIN (nparm)) + { + tree save_arg = arg; + tree tmp = arg; + + /* Arrange to pass indirectly the parms, if we decided to do + so, and revert its type in the wrapper. */ + if (indirect_nparms.contains (nparm)) + { + tree ref_type = TREE_TYPE (nparm); + TREE_ADDRESSABLE (arg) = true; + tree addr = build1 (ADDR_EXPR, ref_type, arg); + tmp = arg = addr; + } +#if ! FOR_GCC_11P + else if (VECTOR_TYPE_P (TREE_TYPE (arg)) + || TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE) + DECL_GIMPLE_REG_P (arg) = 1; +#else + else + DECL_NOT_GIMPLE_REG_P (arg) = 0; +#endif + + /* Convert the argument back to the type used by the calling + conventions, e.g. a non-prototyped float type is passed as + double, as in 930603-1.c, and needs to be converted back to + double to be passed on unchanged to the wrapped + function. */ + if (TREE_TYPE (nparm) != DECL_ARG_TYPE (nparm)) + arg = fold_convert (DECL_ARG_TYPE (nparm), arg); + + if (!is_gimple_val (arg)) + { + tmp = create_tmp_reg (TYPE_MAIN_VARIANT + (TREE_TYPE (arg)), "arg"); + gimple *stmt = gimple_build_assign (tmp, arg); + gsi_insert_after (&bsi, stmt, GSI_NEW_STMT); + } + vargs.quick_push (tmp); + arg = save_arg; + } + /* These strub arguments are adjusted later. */ + if (apply_args) + vargs.quick_push (null_pointer_node); + if (is_stdarg) + vargs.quick_push (null_pointer_node); + vargs.quick_push (null_pointer_node); + call = gimple_build_call_vec (build_fold_addr_expr_loc (0, alias), + vargs); + onode->callees->call_stmt = call; + // gimple_call_set_from_thunk (call, true); + if (DECL_STATIC_CHAIN (alias)) + { + tree p = DECL_STRUCT_FUNCTION (alias)->static_chain_decl; + tree type = TREE_TYPE (p); + tree decl = build_decl (DECL_SOURCE_LOCATION (thunk_fndecl), + PARM_DECL, create_tmp_var_name ("CHAIN"), + type); + DECL_ARTIFICIAL (decl) = 1; + DECL_IGNORED_P (decl) = 1; + TREE_USED (decl) = 1; + DECL_CONTEXT (decl) = thunk_fndecl; + DECL_ARG_TYPE (decl) = type; + TREE_READONLY (decl) = 1; + + struct function *sf = DECL_STRUCT_FUNCTION (thunk_fndecl); + sf->static_chain_decl = decl; + + gimple_call_set_chain (call, decl); + } + + /* Return slot optimization is always possible and in fact required to + return values with DECL_BY_REFERENCE. */ + if (aggregate_value_p (resdecl, TREE_TYPE (thunk_fndecl)) + && (!is_gimple_reg_type (TREE_TYPE (resdecl)) + || DECL_BY_REFERENCE (resdecl))) + gimple_call_set_return_slot_opt (call, true); + + if (restmp) + { + gimple_call_set_lhs (call, restmp); + gcc_assert (useless_type_conversion_p (TREE_TYPE (restmp), + TREE_TYPE (TREE_TYPE (alias)))); + } + gsi_insert_after (&bsi, call, GSI_NEW_STMT); + if (!alias_is_noreturn) + { + /* Build return value. */ + if (!DECL_BY_REFERENCE (resdecl)) + ret = gimple_build_return (restmp); + else + ret = gimple_build_return (resdecl); + + gsi_insert_after (&bsi, ret, GSI_NEW_STMT); + } + else + { + remove_edge (single_succ_edge (bb)); + } + + cfun->gimple_df->in_ssa_p = true; + update_max_bb_count (); + profile_status_for_fn (cfun) + = cfg_count.initialized_p () && cfg_count.ipa_p () + ? PROFILE_READ : PROFILE_GUESSED; +#if FOR_GCC_11P + /* FIXME: C++ FE should stop setting TREE_ASM_WRITTEN on thunks. */ + // TREE_ASM_WRITTEN (thunk_fndecl) = false; +#endif + delete_unreachable_blocks (); + update_ssa (TODO_update_ssa); + checking_verify_flow_info (); + free_dominance_info (CDI_DOMINATORS); + + /* Since we want to emit the thunk, we explicitly mark its name as + referenced. */ +#if FOR_GCC_11P + onode->thunk = false; +#else + onode->thunk.thunk_p = false; +#endif + onode->lowered = true; + bitmap_obstack_release (NULL); + } + current_function_decl = NULL; + set_cfun (NULL); + } + +#if FOR_GCC_11P + thunk_info::remove (onode); +#endif + + // some more of create_wrapper at the end of the next block. + } + } + + { + tree aaval = NULL_TREE; + tree vaptr = NULL_TREE; + tree wmptr = NULL_TREE; + for (tree arg = DECL_ARGUMENTS (nnode->decl); arg; arg = DECL_CHAIN (arg)) + { + aaval = vaptr; + vaptr = wmptr; + wmptr = arg; + } + + if (!apply_args) + aaval = NULL_TREE; + /* The trailing args are [apply_args], [va_list_ptr], and + watermark. If we don't have a va_list_ptr, the penultimate + argument is apply_args. + */ + else if (!is_stdarg) + aaval = vaptr; + + if (!is_stdarg) + vaptr = NULL_TREE; + + DECL_NAME (wmptr) = get_watermark_ptr (); + DECL_ARTIFICIAL (wmptr) = 1; + DECL_IGNORED_P (wmptr) = 1; + TREE_USED (wmptr) = 1; + + if (is_stdarg) + { + DECL_NAME (vaptr) = get_va_list_ptr (); + DECL_ARTIFICIAL (vaptr) = 1; + DECL_IGNORED_P (vaptr) = 1; + TREE_USED (vaptr) = 1; + } + + if (apply_args) + { + DECL_NAME (aaval) = get_apply_args (); + DECL_ARTIFICIAL (aaval) = 1; + DECL_IGNORED_P (aaval) = 1; + TREE_USED (aaval) = 1; + } + + push_cfun (DECL_STRUCT_FUNCTION (nnode->decl)); + + { + edge e = single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun)); + gimple_seq seq = call_update_watermark (wmptr, nnode, e->src->count); + gsi_insert_seq_on_edge_immediate (e, seq); + } + + bool any_indirect = !indirect_nparms.is_empty (); + + if (any_indirect) + { + basic_block bb; + bool needs_commit = false; + FOR_EACH_BB_FN (bb, cfun) + { + for (gphi_iterator gsi = gsi_start_nonvirtual_phis (bb); + !gsi_end_p (gsi); + gsi_next_nonvirtual_phi (&gsi)) + { + gphi *stmt = gsi.phi (); + + walk_stmt_info wi = {}; + wi.info = &indirect_nparms; + walk_gimple_op (stmt, walk_make_indirect, &wi); + if (wi.changed && !is_gimple_debug (gsi_stmt (gsi))) + if (walk_regimplify_phi (stmt)) + needs_commit = true; + } + + for (gimple_stmt_iterator gsi = gsi_start_bb (bb); + !gsi_end_p (gsi); gsi_next (&gsi)) + { + gimple *stmt = gsi_stmt (gsi); + + walk_stmt_info wi = {}; + wi.info = &indirect_nparms; + walk_gimple_op (stmt, walk_make_indirect, &wi); + if (wi.changed) + { + if (!is_gimple_debug (stmt)) + { + wi.info = &gsi; + walk_gimple_op (stmt, walk_regimplify_addr_expr, + &wi); + } + update_stmt (stmt); + } + } + } + if (needs_commit) + gsi_commit_edge_inserts (); + } + + if (DECL_STRUCT_FUNCTION (nnode->decl)->calls_alloca + || is_stdarg || apply_args) + for (cgraph_edge *e = nnode->callees, *enext; e; e = enext) + { + gcall *call = e->call_stmt; + gimple_stmt_iterator gsi = gsi_for_stmt (call); + tree fndecl = e->callee->decl; + + enext = e->next_callee; + + if (gimple_alloca_call_p (call)) + { + gimple_seq seq = call_update_watermark (wmptr, NULL, + gsi_bb (gsi)->count); + gsi_insert_finally_seq_after_call (gsi, seq); + } + else if (fndecl && is_stdarg + && fndecl_built_in_p (fndecl, BUILT_IN_VA_START)) + { + /* Using a non-default stdarg ABI makes the function ineligible + for internal strub. */ + gcc_checking_assert (builtin_decl_explicit (BUILT_IN_VA_START) + == fndecl); + tree bvacopy = builtin_decl_explicit (BUILT_IN_VA_COPY); + gimple_call_set_fndecl (call, bvacopy); + tree arg = vaptr; + /* The va_copy source must be dereferenced, unless it's an array + type, that would have decayed to a pointer. */ + if (TREE_CODE (TREE_TYPE (TREE_TYPE (vaptr))) != ARRAY_TYPE) + { + arg = gimple_fold_indirect_ref (vaptr); + if (!arg) + arg = build2 (MEM_REF, + TREE_TYPE (TREE_TYPE (vaptr)), + vaptr, + build_int_cst (TREE_TYPE (vaptr), 0)); + } + gimple_call_set_arg (call, 1, arg); + update_stmt (call); + e->redirect_callee (cgraph_node::get_create (bvacopy)); + } + else if (fndecl && apply_args + && fndecl_built_in_p (fndecl, BUILT_IN_APPLY_ARGS)) + { + tree lhs = gimple_call_lhs (call); + gimple *assign = (lhs + ? gimple_build_assign (lhs, aaval) + : gimple_build_nop ()); + gsi_replace (&gsi, assign, true); + cgraph_edge::remove (e); + } + } + + { // a little more copied from create_wrapper + + /* Inline summary set-up. */ + nnode->analyze (); + // inline_analyze_function (nnode); + } + + pop_cfun (); + } + + { + push_cfun (DECL_STRUCT_FUNCTION (onode->decl)); + gimple_stmt_iterator gsi + = gsi_after_labels (single_succ (ENTRY_BLOCK_PTR_FOR_FN (cfun))); + + gcall *wrcall; + while (!(wrcall = dyn_cast (gsi_stmt (gsi)))) + gsi_next (&gsi); + + tree swm = create_tmp_var (get_wmt (), ".strub.watermark"); + TREE_ADDRESSABLE (swm) = true; + tree swmp = build1 (ADDR_EXPR, get_pwmt (), swm); + + tree enter = get_enter (); + gcall *stptr = gimple_build_call (enter, 1, unshare_expr (swmp)); + gimple_set_location (stptr, gimple_location (wrcall)); + gsi_insert_before (&gsi, stptr, GSI_SAME_STMT); +#if !IMPLICIT_CGRAPH_EDGES + onode->create_edge (cgraph_node::get_create (enter), + stptr, gsi_bb (gsi)->count, false); +#endif + + int nargs = gimple_call_num_args (wrcall); + + gimple_seq seq = NULL; + + if (apply_args) + { + tree aalst = create_tmp_var (ptr_type_node, ".strub.apply_args"); + tree bappargs = builtin_decl_explicit (BUILT_IN_APPLY_ARGS); + gcall *appargs = gimple_build_call (bappargs, 0); + gimple_call_set_lhs (appargs, aalst); + gimple_set_location (appargs, gimple_location (wrcall)); + gsi_insert_before (&gsi, appargs, GSI_SAME_STMT); + gimple_call_set_arg (wrcall, nargs - 2 - is_stdarg, aalst); +#if !IMPLICIT_CGRAPH_EDGES + onode->create_edge (cgraph_node::get_create (bappargs), + appargs, gsi_bb (gsi)->count, false); +#endif + } + + if (is_stdarg) + { + tree valst = create_tmp_var (va_list_type_node, ".strub.va_list"); + TREE_ADDRESSABLE (valst) = true; + tree vaptr = build1 (ADDR_EXPR, + build_pointer_type (va_list_type_node), + valst); + gimple_call_set_arg (wrcall, nargs - 2, unshare_expr (vaptr)); + + tree bvastart = builtin_decl_explicit (BUILT_IN_VA_START); + gcall *vastart = gimple_build_call (bvastart, 2, + unshare_expr (vaptr), + integer_zero_node); + gimple_set_location (vastart, gimple_location (wrcall)); + gsi_insert_before (&gsi, vastart, GSI_SAME_STMT); +#if !IMPLICIT_CGRAPH_EDGES + onode->create_edge (cgraph_node::get_create (bvastart), + vastart, gsi_bb (gsi)->count, false); +#endif + + tree bvaend = builtin_decl_explicit (BUILT_IN_VA_END); + gcall *vaend = gimple_build_call (bvaend, 1, unshare_expr (vaptr)); + gimple_set_location (vaend, gimple_location (wrcall)); + gimple_seq_add_stmt (&seq, vaend); + } + + gimple_call_set_arg (wrcall, nargs - 1, unshare_expr (swmp)); + // gimple_call_set_tail (wrcall, false); + update_stmt (wrcall); + + { +#if !ATTR_FNSPEC_DECONST_WATERMARK + /* If the call will be assumed to not modify or even read the + watermark, make it read and modified ourselves. */ + if ((gimple_call_flags (wrcall) + & (ECF_CONST | ECF_PURE | ECF_NOVOPS))) + { + vec *inputs = NULL; + vec *outputs = NULL; + vec_safe_push (outputs, + build_tree_list + (build_tree_list + (NULL_TREE, build_string (2, "=m")), + swm)); + vec_safe_push (inputs, + build_tree_list + (build_tree_list + (NULL_TREE, build_string (1, "m")), + swm)); + gasm *forcemod = gimple_build_asm_vec ("", inputs, outputs, + NULL, NULL); + gimple_seq_add_stmt (&seq, forcemod); + + /* If the call will be assumed to not even read the watermark, + make sure it is already in memory before the call. */ + if ((gimple_call_flags (wrcall) & ECF_CONST)) + { + vec *inputs = NULL; + vec_safe_push (inputs, + build_tree_list + (build_tree_list + (NULL_TREE, build_string (1, "m")), + swm)); + gasm *force_store = gimple_build_asm_vec ("", inputs, NULL, + NULL, NULL); + gimple_set_location (force_store, gimple_location (wrcall)); + gsi_insert_before (&gsi, force_store, GSI_SAME_STMT); + } + } +#endif + + gcall *sleave = gimple_build_call (get_leave (), 1, + unshare_expr (swmp)); + gimple_seq_add_stmt (&seq, sleave); + + gassign *clobber = gimple_build_assign (swm, + build_clobber + (TREE_TYPE (swm))); + gimple_seq_add_stmt (&seq, clobber); + } + + gsi_insert_finally_seq_after_call (gsi, seq); + + /* For nnode, we don't rebuild edges because we wish to retain + any redirections copied to it from earlier passes, so we add + call graph edges explicitly there, but for onode, we create a + fresh function, so we may as well just issue the calls and + then rebuild all cgraph edges. */ + // cgraph_edge::rebuild_edges (); + onode->analyze (); + // inline_analyze_function (onode); + + pop_cfun (); + } + } + + return 0; +} + +simple_ipa_opt_pass * +make_pass_ipa_strub (gcc::context *ctxt) +{ + return new pass_ipa_strub (ctxt); +} diff --git a/gcc/ipa-strub.h b/gcc/ipa-strub.h new file mode 100644 index 0000000000000..5c0b266c3f81b --- /dev/null +++ b/gcc/ipa-strub.h @@ -0,0 +1,45 @@ +/* strub (stack scrubbing) infrastructure. + Copyright (C) 2021 Free Software Foundation, Inc. + Contributed by Alexandre Oliva . + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 3, or (at your option) any later +version. + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING3. If not see +. */ + +/* Return TRUE if CALLEE can be inlined into CALLER, as far as stack scrubbing + constraints are concerned. CALLEE doesn't have to be called directly by + CALLER, but the returned value says nothing about intervening functions. */ +extern bool strub_inlinable_to_p (cgraph_node *callee, cgraph_node *caller); + +/* Return FALSE if NODE is a strub context, and TRUE otherwise. */ +extern bool strub_splittable_p (cgraph_node *node); + +/* Locate and return the watermark_ptr parameter for FNDECL. If FNDECL is not a + strub context, return NULL. */ +extern tree strub_watermark_parm (tree fndecl); + +/* Make a function type or declaration callable. */ +extern void strub_make_callable (tree fndecl); + +/* Return zero iff ID is NOT an acceptable parameter for a user-supplied strub + attribute for a function. Otherwise, return >0 if it enables strub, <0 if it + does not. Return +/-1 if the attribute-modified type is compatible with the + type without the attribute, or +/-2 if it is not compatible. */ +extern int strub_validate_fn_attr_parm (tree id); + +/* Like comptypes, return 0 if t1 and t2 are not compatible, 1 if they are + compatible, and 2 if they are nearly compatible. Same strub mode is + compatible, interface-compatible strub modes are nearly compatible. */ +extern int strub_comptypes (tree t1, tree t2); diff --git a/gcc/multiple_target.c b/gcc/multiple_target.c index 28d5f95dca52b..07cdb66e337bd 100644 --- a/gcc/multiple_target.c +++ b/gcc/multiple_target.c @@ -557,7 +557,7 @@ public: bool pass_target_clone::gate (function *) { - return true; + return !seen_error (); } } // anon namespace diff --git a/gcc/passes.def b/gcc/passes.def index d7a1f8c97a676..8e4638d20edac 100644 --- a/gcc/passes.def +++ b/gcc/passes.def @@ -53,6 +53,7 @@ along with GCC; see the file COPYING3. If not see INSERT_PASSES_AFTER (all_small_ipa_passes) NEXT_PASS (pass_ipa_free_lang_data); NEXT_PASS (pass_ipa_function_and_variable_visibility); + NEXT_PASS (pass_ipa_strub_mode); NEXT_PASS (pass_build_ssa_passes); PUSH_INSERT_PASSES_WITHIN (pass_build_ssa_passes) NEXT_PASS (pass_fixup_cfg); @@ -111,6 +112,7 @@ along with GCC; see the file COPYING3. If not see POP_INSERT_PASSES () NEXT_PASS (pass_ipa_remove_symbols); + NEXT_PASS (pass_ipa_strub); NEXT_PASS (pass_ipa_oacc); PUSH_INSERT_PASSES_WITHIN (pass_ipa_oacc) NEXT_PASS (pass_ipa_pta); diff --git a/gcc/testsuite/c-c++-common/strub-O0.c b/gcc/testsuite/c-c++-common/strub-O0.c new file mode 100644 index 0000000000000..c7a79a6ea0d8a --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-O0.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-O0 -fstrub=strict -fdump-rtl-expand" } */ + +/* At -O0, none of the strub builtins are expanded inline. */ + +int __attribute__ ((__strub__)) var; + +int f() { + return var; +} + +/* { dg-final { scan-rtl-dump "strub_enter" "expand" } } */ +/* { dg-final { scan-rtl-dump "strub_update" "expand" } } */ +/* { dg-final { scan-rtl-dump "strub_leave" "expand" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-O1.c b/gcc/testsuite/c-c++-common/strub-O1.c new file mode 100644 index 0000000000000..96285c975d98e --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-O1.c @@ -0,0 +1,15 @@ +/* { dg-do compile } */ +/* { dg-options "-O1 -fstrub=strict -fdump-rtl-expand" } */ + +/* At -O1, without -fno-inline, we fully expand enter, but neither update nor + leave. */ + +int __attribute__ ((__strub__)) var; + +int f() { + return var; +} + +/* { dg-final { scan-rtl-dump-not "strub_enter" "expand" } } */ +/* { dg-final { scan-rtl-dump "strub_update" "expand" } } */ +/* { dg-final { scan-rtl-dump "strub_leave" "expand" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-O2.c b/gcc/testsuite/c-c++-common/strub-O2.c new file mode 100644 index 0000000000000..8edc0d8aa1321 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-O2.c @@ -0,0 +1,16 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fstrub=strict -fdump-rtl-expand" } */ + +/* At -O2, without -fno-inline, we fully expand enter and update, and add a test + around the leave call. */ + +int __attribute__ ((__strub__)) var; + +int f() { + return var; +} + +/* { dg-final { scan-rtl-dump-not "strub_enter" "expand" } } */ +/* { dg-final { scan-rtl-dump-not "strub_update" "expand" } } */ +/* { dg-final { scan-rtl-dump "strub_leave" "expand" } } */ +/* { dg-final { scan-rtl-dump "\[(\]call\[^\n\]*strub_leave.*\n\[(\]code_label" "expand" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-O2fni.c b/gcc/testsuite/c-c++-common/strub-O2fni.c new file mode 100644 index 0000000000000..c6d900cf3c45b --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-O2fni.c @@ -0,0 +1,15 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fstrub=strict -fdump-rtl-expand -fno-inline" } */ + +/* With -fno-inline, none of the strub builtins are inlined. */ + +int __attribute__ ((__strub__)) var; + +int f() { + return var; +} + +/* { dg-final { scan-rtl-dump "strub_enter" "expand" } } */ +/* { dg-final { scan-rtl-dump "strub_update" "expand" } } */ +/* { dg-final { scan-rtl-dump "strub_leave" "expand" } } */ +/* { dg-final { scan-rtl-dump-not "\[(\]call\[^\n\]*strub_leave.*\n\[(\]code_label" "expand" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-O3.c b/gcc/testsuite/c-c++-common/strub-O3.c new file mode 100644 index 0000000000000..33ee465e51cb6 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-O3.c @@ -0,0 +1,12 @@ +/* { dg-do compile } */ +/* { dg-options "-O3 -fstrub=strict -fdump-rtl-expand" } */ + +int __attribute__ ((__strub__)) var; + +int f() { + return var; +} + +/* { dg-final { scan-rtl-dump-not "strub_enter" "expand" } } */ +/* { dg-final { scan-rtl-dump-not "strub_update" "expand" } } */ +/* { dg-final { scan-rtl-dump-not "strub_leave" "expand" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-O3fni.c b/gcc/testsuite/c-c++-common/strub-O3fni.c new file mode 100644 index 0000000000000..2936f82079e18 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-O3fni.c @@ -0,0 +1,15 @@ +/* { dg-do compile } */ +/* { dg-options "-O3 -fstrub=strict -fdump-rtl-expand -fno-inline" } */ + +/* With -fno-inline, none of the strub builtins are inlined. */ + +int __attribute__ ((__strub__)) var; + +int f() { + return var; +} + +/* { dg-final { scan-rtl-dump "strub_enter" "expand" } } */ +/* { dg-final { scan-rtl-dump "strub_update" "expand" } } */ +/* { dg-final { scan-rtl-dump "strub_leave" "expand" } } */ +/* { dg-final { scan-rtl-dump-not "\[(\]call\[^\n\]*strub_leave.*\n\[(\]code_label" "expand" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-Og.c b/gcc/testsuite/c-c++-common/strub-Og.c new file mode 100644 index 0000000000000..479746e57d87e --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-Og.c @@ -0,0 +1,16 @@ +/* { dg-do compile } */ +/* { dg-options "-Og -fstrub=strict -fdump-rtl-expand" } */ + +/* At -Og, without -fno-inline, we fully expand enter, but neither update nor + leave. */ + +int __attribute__ ((__strub__)) var; + +int f() { + return var; +} + +/* { dg-final { scan-rtl-dump-not "strub_enter" "expand" } } */ +/* { dg-final { scan-rtl-dump "strub_update" "expand" } } */ +/* { dg-final { scan-rtl-dump "strub_leave" "expand" } } */ +/* { dg-final { scan-rtl-dump-not "\[(\]call\[^\n\]*strub_leave.*\n\[(\]code_label" "expand" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-Os.c b/gcc/testsuite/c-c++-common/strub-Os.c new file mode 100644 index 0000000000000..2241d4ea07f27 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-Os.c @@ -0,0 +1,18 @@ +/* { dg-do compile } */ +/* { dg-options "-Os -fstrub=strict -fdump-rtl-expand" } */ + +/* At -Os, without -fno-inline, we fully expand enter, and also update. The + expanded update might be larger than a call proper, but argument saving and + restoring required by the call will most often make it larger. The leave + call is left untouched. */ + +int __attribute__ ((__strub__)) var; + +int f() { + return var; +} + +/* { dg-final { scan-rtl-dump-not "strub_enter" "expand" } } */ +/* { dg-final { scan-rtl-dump-not "strub_update" "expand" } } */ +/* { dg-final { scan-rtl-dump "strub_leave" "expand" } } */ +/* { dg-final { scan-rtl-dump-not "\[(\]call\[^\n\]*strub_leave.*\n\[(\]code_label" "expand" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-all1.c b/gcc/testsuite/c-c++-common/strub-all1.c new file mode 100644 index 0000000000000..a322bcc5da606 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-all1.c @@ -0,0 +1,32 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=all -fdump-ipa-strubm -fdump-ipa-strub" } */ + +/* h becomes STRUB_CALLABLE, rather than STRUB_INLINABLE, because of the + strub-enabling -fstrub flag, and gets inlined before pass_ipa_strub. */ +static inline void +__attribute__ ((__always_inline__)) +h() { +} + +/* g becomes STRUB_AT_CALLS, because of the flag. */ +static inline void +g() { + h(); +} + +/* f becomes STRUB_INTERNAL because of the flag, and gets split into + STRUB_WRAPPER and STRUB_WRAPPED. */ +void +f() { + g(); +} + +/* { dg-final { scan-ipa-dump-times "strub \[(\]" 3 "strubm" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]callable\[)\]" 1 "strubm" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]at-calls\[)\]" 1 "strubm" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]internal\[)\]" 1 "strubm" } } */ + +/* { dg-final { scan-ipa-dump-times "strub \[(\]" 3 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]at-calls\[)\]" 1 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]wrapped\[)\]" 1 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]wrapper\[)\]" 1 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-all2.c b/gcc/testsuite/c-c++-common/strub-all2.c new file mode 100644 index 0000000000000..db60026d0e080 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-all2.c @@ -0,0 +1,24 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=all -fdump-ipa-strubm -fdump-ipa-strub" } */ + +/* g becomes STRUB_INTERNAL, because of the flag. Without inline, force_output + is set for static non-inline functions when not optimizing, and that keeps + only_called_directly_p from returning true, which makes STRUB_AT_CALLS + non-viable. */ +static void +g() { +} + +/* f becomes STRUB_INTERNAL because of the flag, and gets split into + STRUB_WRAPPER and STRUB_WRAPPED. */ +void +f() { + g(); +} + +/* { dg-final { scan-ipa-dump-times "strub \[(\]" 2 "strubm" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]internal\[)\]" 2 "strubm" } } */ + +/* { dg-final { scan-ipa-dump-times "strub \[(\]" 4 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]wrapped\[)\]" 2 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]wrapper\[)\]" 2 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-apply1.c b/gcc/testsuite/c-c++-common/strub-apply1.c new file mode 100644 index 0000000000000..2f462adc1efe0 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-apply1.c @@ -0,0 +1,15 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict" } */ + +void __attribute__ ((__strub__ ("callable"))) +apply_function (void *args) +{ + __builtin_apply (0, args, 0); +} + +void __attribute__ ((__strub__ ("internal"))) +apply_args (int i, int j, double d) +{ + void *args = __builtin_apply_args (); + apply_function (args); +} diff --git a/gcc/testsuite/c-c++-common/strub-apply2.c b/gcc/testsuite/c-c++-common/strub-apply2.c new file mode 100644 index 0000000000000..a5d7551f5da5c --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-apply2.c @@ -0,0 +1,12 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict" } */ + +extern void __attribute__ ((__strub__)) +apply_function (void *args); + +void __attribute__ ((__strub__)) +apply_args (int i, int j, double d) /* { dg-error "selected" } */ +{ + void *args = __builtin_apply_args (); /* { dg-message "does not support" } */ + apply_function (args); +} diff --git a/gcc/testsuite/c-c++-common/strub-apply3.c b/gcc/testsuite/c-c++-common/strub-apply3.c new file mode 100644 index 0000000000000..64422a0d1e880 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-apply3.c @@ -0,0 +1,8 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict" } */ + +void __attribute__ ((__strub__)) +apply_function (void *args) +{ + __builtin_apply (0, args, 0); /* { dg-error "in .strub. context" } */ +} diff --git a/gcc/testsuite/c-c++-common/strub-apply4.c b/gcc/testsuite/c-c++-common/strub-apply4.c new file mode 100644 index 0000000000000..15ffaa031b899 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-apply4.c @@ -0,0 +1,21 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fstrub=strict -fdump-ipa-strubm" } */ + +/* Check that implicit enabling of strub mode selects internal strub when the + function uses __builtin_apply_args, that prevents the optimization to + at-calls mode. */ + +int __attribute__ ((__strub__)) var; + +static inline void +apply_args (int i, int j, double d) +{ + var++; + __builtin_apply_args (); +} + +void f() { + apply_args (1, 2, 3); +} + +/* { dg-final { scan-ipa-dump-times "strub \[(\]internal\[)\]" 1 "strubm" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-at-calls1.c b/gcc/testsuite/c-c++-common/strub-at-calls1.c new file mode 100644 index 0000000000000..b70843b4215a4 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-at-calls1.c @@ -0,0 +1,30 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=at-calls -fdump-ipa-strubm -fdump-ipa-strub" } */ + +/* h becomes STRUB_CALLABLE, rather than STRUB_INLINABLE, because of the + strub-enabling -fstrub flag, and gets inlined before pass_ipa_strub. */ +static inline void +__attribute__ ((__always_inline__)) +h() { +} + +/* g becomes STRUB_AT_CALLS, because of the flag. */ +static inline void +g() { + h(); +} + +/* f does NOT become STRUB_AT_CALLS because it is visible; it becomes + STRUB_CALLABLE. */ +void +f() { + g(); +} + +/* { dg-final { scan-ipa-dump-times "strub \[(\]" 3 "strubm" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]at-calls\[)\]" 1 "strubm" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]callable\[)\]" 2 "strubm" } } */ + +/* { dg-final { scan-ipa-dump-times "strub \[(\]" 2 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]at-calls\[)\]" 1 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]callable\[)\]" 1 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-at-calls2.c b/gcc/testsuite/c-c++-common/strub-at-calls2.c new file mode 100644 index 0000000000000..97a3988a6b922 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-at-calls2.c @@ -0,0 +1,23 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=at-calls -fdump-ipa-strubm -fdump-ipa-strub" } */ + +/* g does NOT become STRUB_AT_CALLS because it's not viable. Without inline, + force_output is set for static non-inline functions when not optimizing, and + that keeps only_called_directly_p from returning true, which makes + STRUB_AT_CALLS non-viable. It becomes STRUB_CALLABLE instead. */ +static void +g() { +} + +/* f does NOT become STRUB_AT_CALLS because it is visible; it becomes + STRUB_CALLABLE. */ +void +f() { + g(); +} + +/* { dg-final { scan-ipa-dump-times "strub \[(\]" 2 "strubm" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]callable\[)\]" 2 "strubm" } } */ + +/* { dg-final { scan-ipa-dump-times "strub \[(\]" 2 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]callable\[)\]" 2 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-defer-O1.c b/gcc/testsuite/c-c++-common/strub-defer-O1.c new file mode 100644 index 0000000000000..3d73431b3dcd3 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-defer-O1.c @@ -0,0 +1,7 @@ +/* { dg-do run } */ +/* { dg-options "-fstrub=strict -O1" } */ + +/* Check that a strub function called by another strub function does NOT defer + the strubbing to its caller at -O1. */ + +#include "strub-defer-O2.c" diff --git a/gcc/testsuite/c-c++-common/strub-defer-O2.c b/gcc/testsuite/c-c++-common/strub-defer-O2.c new file mode 100644 index 0000000000000..fddf3c745e7e6 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-defer-O2.c @@ -0,0 +1,8 @@ +/* { dg-do run } */ +/* { dg-options "-fstrub=strict -O2" } */ + +/* Check that a strub function called by another strub function does NOT defer + the strubbing to its caller at -O2. */ + +#define EXPECT_DEFERRAL ! +#include "strub-defer-O3.c" diff --git a/gcc/testsuite/c-c++-common/strub-defer-O3.c b/gcc/testsuite/c-c++-common/strub-defer-O3.c new file mode 100644 index 0000000000000..2bc384ee8d1e6 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-defer-O3.c @@ -0,0 +1,93 @@ +/* { dg-do run } */ +/* { dg-options "-fstrub=strict -O3" } */ + +/* Check that a strub function called by another strub function defers the + strubbing to its caller at -O3. */ + +#ifndef EXPECT_DEFERRAL +# define EXPECT_DEFERRAL +#endif + +const char test_string[] = "\x55\xde\xad\xbe\xef\xc0\x1d\xca\xfe\x55\xaa"; + +static inline __attribute__ ((__always_inline__, __strub__ ("callable"))) +char * +leak_string (void) +{ + /* We use this variable to avoid any stack red zone. Stack scrubbing covers + it, but __builtin_stack_address, that we take as a reference, doesn't, so + if e.g. callable() were to store the string in the red zone, we wouldn't + find it because it would be outside the range we searched. */ + typedef void __attribute__ ((__strub__ ("callable"))) callable_t (char *); + callable_t *f = 0; + + char s[sizeof (test_string)]; + __builtin_strcpy (s, test_string); + asm ("" : "+m" (s), "+r" (f)); + + if (__builtin_expect (!f, 1)) + return (char*)__builtin_stack_address (); + + f (s); + return 0; +} + +static inline __attribute__ ((__always_inline__, __strub__ ("callable"))) +int +look_for_string (char *e) +{ + char *p = (char*)__builtin_stack_address (); + + if (p == e) + __builtin_abort (); + + if (p > e) + { + char *q = p; + p = e; + e = q; + } + + for (char *re = e - sizeof (test_string); p < re; p++) + for (int i = 0; p[i] == test_string[i]; i++) + if (i == sizeof (test_string) - 1) + return i; + + return 0; +} + +static __attribute__ ((__strub__ ("at-calls"), __noinline__, __noclone__)) +char * +at_calls () +{ + return leak_string (); +} + +static __attribute__ ((__strub__ ("at-calls"))) +char * +deferred_at_calls () +{ + char *ret = at_calls (); + if (EXPECT_DEFERRAL !look_for_string (ret)) + __builtin_abort (); + return ret; +} + +static __attribute__ ((__strub__ ("internal"))) +char * +deferred_internal () +{ + char *ret = at_calls (); + if (EXPECT_DEFERRAL !look_for_string (ret)) + __builtin_abort (); + return ret; +} + +int main () +{ + if (look_for_string (deferred_at_calls ())) + __builtin_abort (); + if (look_for_string (deferred_internal ())) + __builtin_abort (); + __builtin_exit (0); +} diff --git a/gcc/testsuite/c-c++-common/strub-defer-Os.c b/gcc/testsuite/c-c++-common/strub-defer-Os.c new file mode 100644 index 0000000000000..fbaf85fe0fafe --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-defer-Os.c @@ -0,0 +1,7 @@ +/* { dg-do run } */ +/* { dg-options "-fstrub=strict -Os" } */ + +/* Check that a strub function called by another strub function defers the + strubbing to its caller at -Os. */ + +#include "strub-defer-O3.c" diff --git a/gcc/testsuite/c-c++-common/strub-internal1.c b/gcc/testsuite/c-c++-common/strub-internal1.c new file mode 100644 index 0000000000000..e9d7b7b9ee0a8 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-internal1.c @@ -0,0 +1,31 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=internal -fdump-ipa-strubm -fdump-ipa-strub" } */ + +/* h becomes STRUB_CALLABLE, rather than STRUB_INLINABLE, because of the + strub-enabling -fstrub flag, and gets inlined before pass_ipa_strub. */ +static inline void +__attribute__ ((__always_inline__)) +h() { +} + +/* g becomes STRUB_INTERNAL because of the flag, and gets split into + STRUB_WRAPPER and STRUB_WRAPPED. */ +static inline void +g() { + h(); +} + +/* f becomes STRUB_INTERNAL because of the flag, and gets split into + STRUB_WRAPPER and STRUB_WRAPPED. */ +void +f() { + g(); +} + +/* { dg-final { scan-ipa-dump-times "strub \[(\]" 3 "strubm" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]callable\[)\]" 1 "strubm" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]internal\[)\]" 2 "strubm" } } */ + +/* { dg-final { scan-ipa-dump-times "strub \[(\]" 4 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]wrapped\[)\]" 2 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]wrapper\[)\]" 2 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-internal2.c b/gcc/testsuite/c-c++-common/strub-internal2.c new file mode 100644 index 0000000000000..8b8e15a51c71c --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-internal2.c @@ -0,0 +1,21 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=internal -fdump-ipa-strubm -fdump-ipa-strub" } */ + +/* g becomes STRUB_INTERNAL, because of the flag. */ +static void +g() { +} + +/* f becomes STRUB_INTERNAL because of the flag, and gets split into + STRUB_WRAPPER and STRUB_WRAPPED. */ +void +f() { + g(); +} + +/* { dg-final { scan-ipa-dump-times "strub \[(\]" 2 "strubm" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]internal\[)\]" 2 "strubm" } } */ + +/* { dg-final { scan-ipa-dump-times "strub \[(\]" 4 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]wrapped\[)\]" 2 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]wrapper\[)\]" 2 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-parms1.c b/gcc/testsuite/c-c++-common/strub-parms1.c new file mode 100644 index 0000000000000..0a4a7539d3489 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-parms1.c @@ -0,0 +1,48 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +#include + +void __attribute__ ((__strub__ ("internal"))) +small_args (int i, long long l, void *p, void **q, double d, char c) +{ +} + +/* { dg-final { scan-ipa-dump "\n(void )?\[^ \]*small_args\[^ \]*.strub.\[0-9\]* \[(\]int i, long long int l, void \\* p, void \\* \\* q, double d, char c, void \\* &\[^&,\]*.strub.watermark_ptr\[)\]" "strub" } } */ +/* { dg-final { scan-ipa-dump " \[^ \]*small_args\[^ \]*.strub.\[0-9\]* \[(\]\[^&\]*&.strub.watermark.\[0-9\]*\[)\]" "strub" } } */ + + +struct large_arg { + int x[128]; +}; + +void __attribute__ ((__strub__ ("internal"))) +large_byref_arg (struct large_arg la) +{ +} + +/* { dg-final { scan-ipa-dump "\n(void )?\[^ \]*large_byref_arg\[^ \]*.strub.\[0-9\]* \[(\]struct large_arg & la, void \\* &\[^&,\]*.strub.watermark_ptr\[)\]" "strub" } } */ +/* { dg-final { scan-ipa-dump " \[^ \]*large_byref_arg\[^ \]*.strub.\[0-9\]* \[(\]&\[^&\]*&.strub.watermark.\[0-9\]*\[)\]" "strub" } } */ + +void __attribute__ ((__strub__ ("internal"))) +std_arg (int i, ...) +{ + va_list vl; + va_start (vl, i); + va_end (vl); +} + +/* { dg-final { scan-ipa-dump "\n(void )?\[^ \]*std_arg\[^ \]*.strub.\[0-9\]* \[(\]int i, \[^&,\]* &\[^&,\]*.strub.va_list_ptr, void \\* &\[^&,\]*.strub.watermark_ptr\[)\]" "strub" } } */ +/* { dg-final { scan-ipa-dump " \[^ \]*std_arg\[^ \]*.strub.\[0-9\]* \[(\]\[^&\]*&.strub.va_list.\[0-9\]*, &.strub.watermark.\[0-9\]*\[)\]" "strub" } } */ +/* { dg-final { scan-ipa-dump-times "va_start \\(" 1 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "va_copy \\(" 1 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "va_end \\(" 2 "strub" } } */ + +void __attribute__ ((__strub__ ("internal"))) +apply_args (int i, int j, double d) +{ + __builtin_apply_args (); +} + +/* { dg-final { scan-ipa-dump "\n(void )?\[^ \]*apply_args\[^ \]*.strub.\[0-9\]* \[(\]int i, int j, double d, void \\*\[^&,\]*.strub.apply_args, void \\* &\[^&,\]*.strub.watermark_ptr\[)\]" "strub" } } */ +/* { dg-final { scan-ipa-dump " \[^ \]*apply_args\[^ \]*.strub.\[0-9\]* \[(\]\[^&\]*.strub.apply_args.\[0-9\]*_\[0-9\]*, &.strub.watermark.\[0-9\]*\[)\]" "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-parms2.c b/gcc/testsuite/c-c++-common/strub-parms2.c new file mode 100644 index 0000000000000..147171d96d5a1 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-parms2.c @@ -0,0 +1,36 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +#include + +void __attribute__ ((__strub__ ("at-calls"))) +small_args (int i, long long l, void *p, void **q, double d, char c) +{ +} + +/* { dg-final { scan-ipa-dump "\n(void )?\[^ \]*small_args\[^ \]* \[(\]int i, long long int l, void \\* p, void \\* \\* q, double d, char c, void \\* &\[^&,\]*.strub.watermark_ptr\[)\]" "strub" } } */ + + +struct large_arg { + int x[128]; +}; + +void __attribute__ ((__strub__ ("at-calls"))) +large_byref_arg (struct large_arg la) +{ +} + +/* { dg-final { scan-ipa-dump "\n(void )?\[^ \]*large_byref_arg\[^ \]* \[(\]struct large_arg la, void \\* &\[^&,\]*.strub.watermark_ptr\[)\]" "strub" } } */ + +void __attribute__ ((__strub__ ("at-calls"))) +std_arg (int i, ...) +{ + va_list vl; + va_start (vl, i); + va_end (vl); +} + +/* { dg-final { scan-ipa-dump "\n(void )?\[^ \]*std_arg\[^ \]* \[(\]int i, void \\* &\[^&,\]*.strub.watermark_ptr\[, .]*\[)\]" "strub" } } */ +/* { dg-final { scan-ipa-dump-times "va_start \\(" 1 "strub" } } */ +/* { dg-final { scan-ipa-dump-not "va_copy \\(" "strub" } } */ +/* { dg-final { scan-ipa-dump-times "va_end \\(" 1 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-parms3.c b/gcc/testsuite/c-c++-common/strub-parms3.c new file mode 100644 index 0000000000000..4e92682895a43 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-parms3.c @@ -0,0 +1,58 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +/* Check that uses of a strub variable implicitly enables internal strub for + publicly-visible functions, and causes the same transformations to their + signatures as those in strub-parms1.c. */ + +#include + +int __attribute__ ((__strub__)) var; + +void +small_args (int i, long long l, void *p, void **q, double d, char c) +{ + var++; +} + +/* { dg-final { scan-ipa-dump "\n(void )?\[^ \]*small_args\[^ \]*.strub.\[0-9\]* \[(\]int i, long long int l, void \\* p, void \\* \\* q, double d, char c, void \\* &\[^&,\]*.strub.watermark_ptr\[)\]" "strub" } } */ +/* { dg-final { scan-ipa-dump " \[^ \]*small_args\[^ \]*.strub.\[0-9\]* \[(\]\[^&\]*&.strub.watermark.\[0-9\]*\[)\]" "strub" } } */ + + +struct large_arg { + int x[128]; +}; + +void +large_byref_arg (struct large_arg la) +{ + var++; +} + +/* { dg-final { scan-ipa-dump "\n(void )?\[^ \]*large_byref_arg\[^ \]*.strub.\[0-9\]* \[(\]struct large_arg & la, void \\* &\[^&,\]*.strub.watermark_ptr\[)\]" "strub" } } */ +/* { dg-final { scan-ipa-dump " \[^ \]*large_byref_arg\[^ \]*.strub.\[0-9\]* \[(\]&\[^&\]*&.strub.watermark.\[0-9\]*\[)\]" "strub" } } */ + +void +std_arg (int i, ...) +{ + va_list vl; + va_start (vl, i); + var++; + va_end (vl); +} + +/* { dg-final { scan-ipa-dump "\n(void )?\[^ \]*std_arg\[^ \]*.strub.\[0-9\]* \[(\]int i, \[^&,\]* &\[^&,\]*.strub.va_list_ptr, void \\* &\[^&,\]*.strub.watermark_ptr\[)\]" "strub" } } */ +/* { dg-final { scan-ipa-dump " \[^ \]*std_arg\[^ \]*.strub.\[0-9\]* \[(\]\[^&\]*&.strub.va_list.\[0-9\]*, &.strub.watermark.\[0-9\]*\[)\]" "strub" } } */ +/* { dg-final { scan-ipa-dump-times "va_start \\(" 1 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "va_copy \\(" 1 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "va_end \\(" 2 "strub" } } */ + +void +apply_args (int i, int j, double d) +{ + var++; + __builtin_apply_args (); +} + +/* { dg-final { scan-ipa-dump "\n(void )?\[^ \]*apply_args\[^ \]*.strub.\[0-9\]* \[(\]int i, int j, double d, void \\*\[^&,\]*.strub.apply_args, void \\* &\[^&,\]*.strub.watermark_ptr\[)\]" "strub" } } */ +/* { dg-final { scan-ipa-dump " \[^ \]*apply_args\[^ \]*.strub.\[0-9\]* \[(\]\[^&\]*.strub.apply_args.\[0-9\]*_\[0-9\]*, &.strub.watermark.\[0-9\]*\[)\]" "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-relaxed1.c b/gcc/testsuite/c-c++-common/strub-relaxed1.c new file mode 100644 index 0000000000000..e2f9d8aebca58 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-relaxed1.c @@ -0,0 +1,18 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=relaxed -fdump-ipa-strubm -fdump-ipa-strub" } */ + +/* The difference between relaxed and strict in this case is that we accept the + call from one internal-strub function to another. Without the error, + inlining takes place. */ + +#include "strub-strict1.c" + +/* { dg-final { scan-ipa-dump-times "strub \[(\]" 3 "strubm" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]inlinable\[)\]" 1 "strubm" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]at-calls-opt\[)\]" 1 "strubm" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]internal\[)\]" 1 "strubm" } } */ + +/* { dg-final { scan-ipa-dump-times "strub \[(\]" 3 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]at-calls-opt\[)\]" 1 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]wrapped\[)\]" 1 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]wrapper\[)\]" 1 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-relaxed2.c b/gcc/testsuite/c-c++-common/strub-relaxed2.c new file mode 100644 index 0000000000000..98474435d2e59 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-relaxed2.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=relaxed -fdump-ipa-strubm -fdump-ipa-strub" } */ + +/* The difference between relaxed and strict in this case is that we accept the + call from one internal-strub function to another. */ + +#include "strub-strict2.c" + +/* { dg-final { scan-ipa-dump-times "strub \[(\]" 2 "strubm" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]internal\[)\]" 2 "strubm" } } */ + +/* { dg-final { scan-ipa-dump-times "strub \[(\]" 4 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]wrapped\[)\]" 2 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]wrapper\[)\]" 2 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-short-O0-exc.c b/gcc/testsuite/c-c++-common/strub-short-O0-exc.c new file mode 100644 index 0000000000000..1de15342595e4 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-short-O0-exc.c @@ -0,0 +1,10 @@ +/* { dg-do compile } */ +/* { dg-options "-O0 -fstrub=strict -fexceptions -fdump-ipa-strub" } */ + +/* Check that the expected strub calls are issued. */ + +#include "torture/strub-callable1.c" + +/* { dg-final { scan-ipa-dump-times "strub_enter" 45 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub_update" 4 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub_leave" 89 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-short-O0.c b/gcc/testsuite/c-c++-common/strub-short-O0.c new file mode 100644 index 0000000000000..f9209c819004b --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-short-O0.c @@ -0,0 +1,10 @@ +/* { dg-do compile } */ +/* { dg-options "-O0 -fstrub=strict -fno-exceptions -fdump-ipa-strub" } */ + +/* Check that the expected strub calls are issued. */ + +#include "torture/strub-callable1.c" + +/* { dg-final { scan-ipa-dump-times "strub_enter" 45 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub_update" 4 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub_leave" 45 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-short-O1.c b/gcc/testsuite/c-c++-common/strub-short-O1.c new file mode 100644 index 0000000000000..bed1dcfb54a45 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-short-O1.c @@ -0,0 +1,10 @@ +/* { dg-do compile } */ +/* { dg-options "-O1 -fstrub=strict -fno-exceptions -fdump-ipa-strub" } */ + +/* Check that the expected strub calls are issued. */ + +#include "torture/strub-callable1.c" + +/* { dg-final { scan-ipa-dump-times "strub_enter" 45 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub_update" 4 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub_leave" 45 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-short-O2.c b/gcc/testsuite/c-c++-common/strub-short-O2.c new file mode 100644 index 0000000000000..6bf0071f52b93 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-short-O2.c @@ -0,0 +1,10 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fstrub=strict -fno-exceptions -fdump-ipa-strub" } */ + +/* Check that the expected strub calls are issued. */ + +#include "torture/strub-callable1.c" + +/* { dg-final { scan-ipa-dump-times "strub_enter" 45 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub_update" 4 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub_leave" 45 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-short-O3.c b/gcc/testsuite/c-c++-common/strub-short-O3.c new file mode 100644 index 0000000000000..4732f515bf70c --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-short-O3.c @@ -0,0 +1,12 @@ +/* { dg-do compile } */ +/* { dg-options "-O3 -fstrub=strict -fno-exceptions -fdump-ipa-strub" } */ + +/* Check that the expected strub calls are issued. At -O3 and -Os, we omit + enter and leave calls within strub contexts, passing on the enclosing + watermark. */ + +#include "torture/strub-callable1.c" + +/* { dg-final { scan-ipa-dump-times "strub_enter" 15 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub_update" 4 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub_leave" 15 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-short-Os.c b/gcc/testsuite/c-c++-common/strub-short-Os.c new file mode 100644 index 0000000000000..8d6424c479a3a --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-short-Os.c @@ -0,0 +1,12 @@ +/* { dg-do compile } */ +/* { dg-options "-Os -fstrub=strict -fno-exceptions -fdump-ipa-strub" } */ + +/* Check that the expected strub calls are issued. At -O3 and -Os, we omit + enter and leave calls within strub contexts, passing on the enclosing + watermark. */ + +#include "torture/strub-callable1.c" + +/* { dg-final { scan-ipa-dump-times "strub_enter" 15 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub_update" 4 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub_leave" 15 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-strict1.c b/gcc/testsuite/c-c++-common/strub-strict1.c new file mode 100644 index 0000000000000..368522442066e --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-strict1.c @@ -0,0 +1,36 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strubm" } */ + +static int __attribute__ ((__strub__)) var; + +/* h becomes STRUB_INLINABLE, because of the use of the strub variable, + and the always_inline flag. It would get inlined before pass_ipa_strub, if + it weren't for the error. */ +static inline void +__attribute__ ((__always_inline__)) +h() { + var++; +} + +/* g becomes STRUB_AT_CALLS_OPT, because of the use of the strub variable, and + the viability of at-calls strubbing. Though internally a strub context, its + interface is not strub-enabled, so it's not callable from within strub + contexts. */ +static inline void +g() { + var--; + h(); +} + +/* f becomes STRUB_INTERNAL because of the use of the strub variable, and gets + split into STRUB_WRAPPER and STRUB_WRAPPED. */ +void +f() { + var++; + g(); /* { dg-error "calling non-.strub." } */ +} + +/* { dg-final { scan-ipa-dump-times "strub \[(\]" 3 "strubm" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]inlinable\[)\]" 1 "strubm" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]at-calls-opt\[)\]" 1 "strubm" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]internal\[)\]" 1 "strubm" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-strict2.c b/gcc/testsuite/c-c++-common/strub-strict2.c new file mode 100644 index 0000000000000..b4f2888321821 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-strict2.c @@ -0,0 +1,25 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strubm" } */ + +static int __attribute__ ((__strub__)) var; + +/* g becomes STRUB_INTERNAL because of the use of the strub variable, and gets + split into STRUB_WRAPPER and STRUB_WRAPPED. It's not STRUB_AT_CALLS_OPT + because force_output is set for static non-inline functions when not + optimizing, and that keeps only_called_directly_p from returning true, which + makes STRUB_AT_CALLS[_OPT] non-viable. */ +static void +g() { + var--; +} + +/* f becomes STRUB_INTERNAL because of the use of the strub variable, and gets + split into STRUB_WRAPPER and STRUB_WRAPPED. */ +void +f() { + var++; + g(); /* { dg-error "calling non-.strub." } */ +} + +/* { dg-final { scan-ipa-dump-times "strub \[(\]" 2 "strubm" } } */ +/* { dg-final { scan-ipa-dump-times "strub \[(\]internal\[)\]" 2 "strubm" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-tail-O1.c b/gcc/testsuite/c-c++-common/strub-tail-O1.c new file mode 100644 index 0000000000000..e48e0610e079b --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-tail-O1.c @@ -0,0 +1,8 @@ +/* { dg-do compile } */ +/* { dg-options "-O1 -fstrub=strict -fno-exceptions -fdump-ipa-strub" } */ + +#include "strub-tail-O2.c" + +/* { dg-final { scan-ipa-dump-times "strub_enter" 2 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub_update" 2 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub_leave" 2 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/strub-tail-O2.c b/gcc/testsuite/c-c++-common/strub-tail-O2.c new file mode 100644 index 0000000000000..87cda7ab21b16 --- /dev/null +++ b/gcc/testsuite/c-c++-common/strub-tail-O2.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fstrub=strict -fno-exceptions -fdump-ipa-strub" } */ + +/* Check that the expected strub calls are issued. + Tail calls are short-circuited at -O2+. */ + +int __attribute__ ((__strub__)) +g (int i, int j) { + return g (i, j); +} + +/* { dg-final { scan-ipa-dump-times "strub_enter" 0 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub_update" 2 "strub" } } */ +/* { dg-final { scan-ipa-dump-times "strub_leave" 0 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/torture/strub-callable1.c b/gcc/testsuite/c-c++-common/torture/strub-callable1.c new file mode 100644 index 0000000000000..b5e45ab0525ad --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-callable1.c @@ -0,0 +1,9 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict" } */ + +/* Check that strub and non-strub functions can be called from non-strub + contexts, and that strub and callable functions can be called from strub + contexts. */ + +#define OMIT_IMPERMISSIBLE_CALLS 1 +#include "strub-callable2.c" diff --git a/gcc/testsuite/c-c++-common/torture/strub-callable2.c b/gcc/testsuite/c-c++-common/torture/strub-callable2.c new file mode 100644 index 0000000000000..96aa7fe4b07f7 --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-callable2.c @@ -0,0 +1,264 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict" } */ + +/* Check that impermissible (cross-strub-context) calls are reported. */ + +extern int __attribute__ ((__strub__ ("callable"))) xcallable (void); +extern int __attribute__ ((__strub__ ("internal"))) xinternal (void); +extern int __attribute__ ((__strub__ ("at-calls"))) xat_calls (void); +extern int __attribute__ ((__strub__ ("disabled"))) xdisabled (void); + +int __attribute__ ((__strub__ ("callable"))) callable (void); +int __attribute__ ((__strub__ ("internal"))) internal (void); +int __attribute__ ((__strub__ ("at-calls"))) at_calls (void); +int __attribute__ ((__strub__ ("disabled"))) disabled (void); + +int __attribute__ ((__strub__)) var; +int var_user (void); + +static inline int __attribute__ ((__always_inline__, __strub__ ("callable"))) +icallable (void); +static inline int __attribute__ ((__always_inline__, __strub__ ("internal"))) +iinternal (void); +static inline int __attribute__ ((__always_inline__, __strub__ ("at-calls"))) +iat_calls (void); +static inline int __attribute__ ((__always_inline__, __strub__ ("disabled"))) +idisabled (void); +static inline int __attribute__ ((__always_inline__)) +ivar_user (void); + +static inline int __attribute__ ((__always_inline__, __strub__ ("callable"))) +i_callable (void) { return 0; } +static inline int __attribute__ ((__always_inline__, __strub__ ("internal"))) +i_internal (void) { return var; } +static inline int __attribute__ ((__always_inline__, __strub__ ("at-calls"))) +i_at_calls (void) { return var; } +static inline int __attribute__ ((__always_inline__, __strub__ ("disabled"))) +i_disabled (void) { return 0; } +static inline int __attribute__ ((__always_inline__)) +i_var_user (void) { return var; } + +#define CALLS_GOOD_FOR_STRUB_CONTEXT(ISEP) \ + do { \ + ret += i ## ISEP ## at_calls (); \ + ret += i ## ISEP ## internal (); \ + ret += i ## ISEP ## var_user (); \ + } while (0) + +#define CALLS_GOOD_FOR_NONSTRUB_CONTEXT(ISEP) \ + do { \ + ret += internal (); \ + ret += disabled (); \ + ret += var_user (); \ + \ + ret += i ## ISEP ## disabled (); \ + \ + ret += xinternal (); \ + ret += xdisabled (); \ + } while (0) + +#define CALLS_GOOD_FOR_EITHER_CONTEXT(ISEP) \ + do { \ + ret += i ## ISEP ## callable (); \ + \ + ret += callable (); \ + ret += at_calls (); \ + \ + ret += xat_calls (); \ + ret += xcallable (); \ + } while (0) + +/* Not a strub context, so it can call anything. + Explicitly declared as callable even from within strub contexts. */ +int __attribute__ ((__strub__ ("callable"))) +callable (void) { + int ret = 0; + + /* CALLS_GOOD_FOR_STRUB_CONTEXT(); */ +#if !OMIT_IMPERMISSIBLE_CALLS + ret += iat_calls (); /* { dg-error "in non-.strub. context" } */ + ret += iinternal (); /* { dg-error "in non-.strub. context" } */ + ret += ivar_user (); /* { dg-error "in non-.strub. context" } */ +#endif + CALLS_GOOD_FOR_EITHER_CONTEXT(); + CALLS_GOOD_FOR_NONSTRUB_CONTEXT(); + + return ret; +} + +/* Internal strubbing means the body is a strub context, so it can only call + strub functions, and it's not itself callable from strub functions. */ +int __attribute__ ((__strub__ ("internal"))) +internal (void) { + int ret = var; + + CALLS_GOOD_FOR_STRUB_CONTEXT(); + CALLS_GOOD_FOR_EITHER_CONTEXT(); + /* CALLS_GOOD_FOR_NONSTRUB_CONTEXT(); */ +#if !OMIT_IMPERMISSIBLE_CALLS + ret += internal (); /* { dg-error "in .strub. context" } */ + ret += disabled (); /* { dg-error "in .strub. context" } */ + ret += var_user (); /* { dg-error "in .strub. context" } */ + + ret += idisabled (); /* { dg-error "in .strub. context" } */ + + ret += xinternal (); /* { dg-error "in .strub. context" } */ + ret += xdisabled (); /* { dg-error "in .strub. context" } */ +#endif + + return ret; +} + +int __attribute__ ((__strub__ ("at-calls"))) +at_calls (void) { + int ret = var; + + CALLS_GOOD_FOR_STRUB_CONTEXT(); + CALLS_GOOD_FOR_EITHER_CONTEXT(); + /* CALLS_GOOD_FOR_NONSTRUB_CONTEXT(); */ +#if !OMIT_IMPERMISSIBLE_CALLS + ret += internal (); /* { dg-error "in .strub. context" } */ + ret += disabled (); /* { dg-error "in .strub. context" } */ + ret += var_user (); /* { dg-error "in .strub. context" } */ + + ret += idisabled (); /* { dg-error "in .strub. context" } */ + + ret += xinternal (); /* { dg-error "in .strub. context" } */ + ret += xdisabled (); /* { dg-error "in .strub. context" } */ +#endif + + return ret; +} + +int __attribute__ ((__strub__ ("disabled"))) +disabled () { + int ret = 0; + + /* CALLS_GOOD_FOR_STRUB_CONTEXT(); */ +#if !OMIT_IMPERMISSIBLE_CALLS + ret += iat_calls (); /* { dg-error "in non-.strub. context" } */ + ret += iinternal (); /* { dg-error "in non-.strub. context" } */ + ret += ivar_user (); /* { dg-error "in non-.strub. context" } */ +#endif + CALLS_GOOD_FOR_EITHER_CONTEXT(); + CALLS_GOOD_FOR_NONSTRUB_CONTEXT(); + + return ret; +} + +int +var_user (void) { + int ret = var; + + CALLS_GOOD_FOR_STRUB_CONTEXT(); + CALLS_GOOD_FOR_EITHER_CONTEXT(); + /* CALLS_GOOD_FOR_NONSTRUB_CONTEXT(); */ +#if !OMIT_IMPERMISSIBLE_CALLS + ret += internal (); /* { dg-error "in .strub. context" } */ + ret += disabled (); /* { dg-error "in .strub. context" } */ + ret += var_user (); /* { dg-error "in .strub. context" } */ + + ret += idisabled (); /* { dg-error "in .strub. context" } */ + + ret += xinternal (); /* { dg-error "in .strub. context" } */ + ret += xdisabled (); /* { dg-error "in .strub. context" } */ +#endif + + return ret; +} + +int +icallable (void) +{ + int ret = 0; + + /* CALLS_GOOD_FOR_STRUB_CONTEXT(_); */ +#if !OMIT_IMPERMISSIBLE_CALLS + ret += i_at_calls (); /* { dg-error "in non-.strub. context" } */ + ret += i_internal (); /* { dg-error "in non-.strub. context" } */ + ret += i_var_user (); /* { dg-error "in non-.strub. context" } */ +#endif + CALLS_GOOD_FOR_EITHER_CONTEXT(_); + CALLS_GOOD_FOR_NONSTRUB_CONTEXT(_); + + return ret; +} + +int +iinternal (void) { + int ret = var; + + CALLS_GOOD_FOR_STRUB_CONTEXT(_); + CALLS_GOOD_FOR_EITHER_CONTEXT(_); + /* CALLS_GOOD_FOR_NONSTRUB_CONTEXT(_); */ +#if !OMIT_IMPERMISSIBLE_CALLS + ret += internal (); /* { dg-error "in .strub. context" } */ + ret += disabled (); /* { dg-error "in .strub. context" } */ + ret += var_user (); /* { dg-error "in .strub. context" } */ + + ret += i_disabled (); /* { dg-error "in .strub. context" } */ + + ret += xinternal (); /* { dg-error "in .strub. context" } */ + ret += xdisabled (); /* { dg-error "in .strub. context" } */ +#endif + + return ret; +} + +int __attribute__ ((__always_inline__, __strub__ ("at-calls"))) +iat_calls (void) { + int ret = var; + + CALLS_GOOD_FOR_STRUB_CONTEXT(_); + CALLS_GOOD_FOR_EITHER_CONTEXT(_); + /* CALLS_GOOD_FOR_NONSTRUB_CONTEXT(_); */ +#if !OMIT_IMPERMISSIBLE_CALLS + ret += internal (); /* { dg-error "in .strub. context" } */ + ret += disabled (); /* { dg-error "in .strub. context" } */ + ret += var_user (); /* { dg-error "in .strub. context" } */ + + ret += i_disabled (); /* { dg-error "in .strub. context" } */ + + ret += xinternal (); /* { dg-error "in .strub. context" } */ + ret += xdisabled (); /* { dg-error "in .strub. context" } */ +#endif + + return ret; +} + +int +idisabled () { + int ret = 0; + + /* CALLS_GOOD_FOR_STRUB_CONTEXT(_); */ +#if !OMIT_IMPERMISSIBLE_CALLS + ret += i_at_calls (); /* { dg-error "in non-.strub. context" } */ + ret += i_internal (); /* { dg-error "in non-.strub. context" } */ + ret += i_var_user (); /* { dg-error "in non-.strub. context" } */ +#endif + CALLS_GOOD_FOR_EITHER_CONTEXT(_); + CALLS_GOOD_FOR_NONSTRUB_CONTEXT(_); + + return ret; +} + +int +ivar_user (void) { + int ret = var; + + CALLS_GOOD_FOR_STRUB_CONTEXT(_); + CALLS_GOOD_FOR_EITHER_CONTEXT(_); + /* CALLS_GOOD_FOR_NONSTRUB_CONTEXT(_); */ +#if !OMIT_IMPERMISSIBLE_CALLS + ret += internal (); /* { dg-error "in .strub. context" } */ + ret += disabled (); /* { dg-error "in .strub. context" } */ + ret += var_user (); /* { dg-error "in .strub. context" } */ + + ret += i_disabled (); /* { dg-error "in .strub. context" } */ + + ret += xinternal (); /* { dg-error "in .strub. context" } */ + ret += xdisabled (); /* { dg-error "in .strub. context" } */ +#endif + + return ret; +} diff --git a/gcc/testsuite/c-c++-common/torture/strub-const1.c b/gcc/testsuite/c-c++-common/torture/strub-const1.c new file mode 100644 index 0000000000000..2857195706ed6 --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-const1.c @@ -0,0 +1,18 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +/* Check that, along with a strub const function call, we issue an asm statement + to make sure the watermark passed to it is held in memory before the call, + and another to make sure it is not assumed to be unchanged. */ + +int __attribute__ ((__strub__, __const__)) +f() { + return 0; +} + +int +g() { + return f(); +} + +/* { dg-final { scan-ipa-dump-times "__asm__" 2 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/torture/strub-const2.c b/gcc/testsuite/c-c++-common/torture/strub-const2.c new file mode 100644 index 0000000000000..98a92bc9eac2b --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-const2.c @@ -0,0 +1,22 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +/* Check that, along with a strub implicitly-const function call, we issue an + asm statement to make sure the watermark passed to it is held in memory + before the call, and another to make sure it is not assumed to be + unchanged. */ + +int __attribute__ ((__strub__)) +#if ! __OPTIMIZE__ +__attribute__ ((__const__)) +#endif +f() { + return 0; +} + +int +g() { + return f(); +} + +/* { dg-final { scan-ipa-dump-times "__asm__" 2 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/torture/strub-const3.c b/gcc/testsuite/c-c++-common/torture/strub-const3.c new file mode 100644 index 0000000000000..5511a6e1e71d3 --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-const3.c @@ -0,0 +1,13 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +/* Check that, along with a strub const wrapping call, we issue an asm statement + to make sure the watermark passed to it is held in memory before the call, + and another to make sure it is not assumed to be unchanged. */ + +int __attribute__ ((__strub__ ("internal"), __const__)) +f() { + return 0; +} + +/* { dg-final { scan-ipa-dump-times "__asm__" 2 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/torture/strub-const4.c b/gcc/testsuite/c-c++-common/torture/strub-const4.c new file mode 100644 index 0000000000000..47ee927964dff --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-const4.c @@ -0,0 +1,17 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +/* Check that, along with a strub implicitly-const wrapping call, we issue an + asm statement to make sure the watermark passed to it is held in memory + before the call, and another to make sure it is not assumed to be + unchanged. */ + +int __attribute__ ((__strub__ ("internal"))) +#if ! __OPTIMIZE__ +__attribute__ ((__const__)) +#endif +f() { + return 0; +} + +/* { dg-final { scan-ipa-dump-times "__asm__" 2 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/torture/strub-data1.c b/gcc/testsuite/c-c++-common/torture/strub-data1.c new file mode 100644 index 0000000000000..7c27a2a1a6dca --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-data1.c @@ -0,0 +1,13 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +/* The pointed-to data enables strubbing if accessed. */ +int __attribute__ ((__strub__)) var; + +int f() { + return var; +} + +/* { dg-final { scan-ipa-dump "strub_enter" "strub" } } */ +/* { dg-final { scan-ipa-dump "strub_leave" "strub" } } */ +/* { dg-final { scan-ipa-dump "strub_update" "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/torture/strub-data2.c b/gcc/testsuite/c-c++-common/torture/strub-data2.c new file mode 100644 index 0000000000000..e66d903780afd --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-data2.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +/* The pointer itself is a strub variable, enabling internal strubbing when + its value is used. */ +int __attribute__ ((__strub__)) *ptr; + +int *f() { + return ptr; +} + +/* { dg-final { scan-ipa-dump "strub_enter" "strub" } } */ +/* { dg-final { scan-ipa-dump "strub_leave" "strub" } } */ +/* { dg-final { scan-ipa-dump "strub_update" "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/torture/strub-data3.c b/gcc/testsuite/c-c++-common/torture/strub-data3.c new file mode 100644 index 0000000000000..5e08e0e58c658 --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-data3.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +/* The pointer itself is a strub variable, that would enable internal strubbing + if its value was used. Here, it's only overwritten, so no strub. */ +int __attribute__ ((__strub__)) var; + +void f() { + var = 0; +} + +/* { dg-final { scan-ipa-dump-not "strub_enter" "strub" } } */ +/* { dg-final { scan-ipa-dump-not "strub_leave" "strub" } } */ +/* { dg-final { scan-ipa-dump-not "strub_update" "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/torture/strub-data4.c b/gcc/testsuite/c-c++-common/torture/strub-data4.c new file mode 100644 index 0000000000000..a818e7a38bb5f --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-data4.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +/* The pointer itself is a strub variable, that would enable internal strubbing + if its value was used. Here, it's only overwritten, so no strub. */ +int __attribute__ ((__strub__)) *ptr; + +void f() { + ptr = 0; +} + +/* { dg-final { scan-ipa-dump-not "strub_enter" "strub" } } */ +/* { dg-final { scan-ipa-dump-not "strub_leave" "strub" } } */ +/* { dg-final { scan-ipa-dump-not "strub_update" "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/torture/strub-data5.c b/gcc/testsuite/c-c++-common/torture/strub-data5.c new file mode 100644 index 0000000000000..ddb0b5c0543b0 --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-data5.c @@ -0,0 +1,15 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict" } */ + +/* It would be desirable to issue at least warnings for these. */ + +typedef int __attribute__ ((__strub__)) strub_int; +strub_int *ptr; + +int *f () { + return ptr; /* { dg-message "incompatible|invalid conversion" } */ +} + +strub_int *g () { + return f (); /* { dg-message "incompatible|invalid conversion" } */ +} diff --git a/gcc/testsuite/c-c++-common/torture/strub-indcall1.c b/gcc/testsuite/c-c++-common/torture/strub-indcall1.c new file mode 100644 index 0000000000000..c165f312f16de --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-indcall1.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +typedef void __attribute__ ((__strub__)) fntype (); +fntype (*ptr); + +void f() { + ptr (); +} + +/* { dg-final { scan-ipa-dump "strub_enter" "strub" } } */ +/* { dg-final { scan-ipa-dump "(&\.strub\.watermark\.\[0-9\]\+)" "strub" } } */ +/* { dg-final { scan-ipa-dump "strub_leave" "strub" } } */ +/* { dg-final { scan-ipa-dump-not "strub_update" "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/torture/strub-indcall2.c b/gcc/testsuite/c-c++-common/torture/strub-indcall2.c new file mode 100644 index 0000000000000..69fcff8d3763d --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-indcall2.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +typedef void __attribute__ ((__strub__)) fntype (int, int); +fntype (*ptr); + +void f() { + ptr (0, 0); +} + +/* { dg-final { scan-ipa-dump "strub_enter" "strub" } } */ +/* { dg-final { scan-ipa-dump "(0, 0, &\.strub\.watermark\.\[0-9\]\+)" "strub" } } */ +/* { dg-final { scan-ipa-dump "strub_leave" "strub" } } */ +/* { dg-final { scan-ipa-dump-not "strub_update" "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/torture/strub-indcall3.c b/gcc/testsuite/c-c++-common/torture/strub-indcall3.c new file mode 100644 index 0000000000000..ff006224909bd --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-indcall3.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +typedef void __attribute__ ((__strub__)) fntype (int, int, ...); +fntype (*ptr); + +void f() { + ptr (0, 0, 1, 1); +} + +/* { dg-final { scan-ipa-dump "strub_enter" "strub" } } */ +/* { dg-final { scan-ipa-dump "(0, 0, &\.strub\.watermark\.\[0-9\]\+, 1, 1)" "strub" } } */ +/* { dg-final { scan-ipa-dump "strub_leave" "strub" } } */ +/* { dg-final { scan-ipa-dump-not "strub_update" "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/torture/strub-inlinable1.c b/gcc/testsuite/c-c++-common/torture/strub-inlinable1.c new file mode 100644 index 0000000000000..614b02228ba29 --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-inlinable1.c @@ -0,0 +1,16 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=relaxed" } */ + +inline void __attribute__ ((strub ("internal"), always_inline)) +inl_int_ali (void) +{ + /* No internal wrapper, so this body ALWAYS gets inlined, + but it cannot be called from non-strub contexts. */ +} + +void +bat (void) +{ + /* Not allowed, not a strub context. */ + inl_int_ali (); /* { dg-error "context" } */ +} diff --git a/gcc/testsuite/c-c++-common/torture/strub-inlinable2.c b/gcc/testsuite/c-c++-common/torture/strub-inlinable2.c new file mode 100644 index 0000000000000..f9a6b4a16faf8 --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-inlinable2.c @@ -0,0 +1,7 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=all" } */ + +#include "strub-inlinable1.c" + +/* With -fstrub=all, the caller becomes a strub context, so the strub-inlinable + callee is not rejected. */ diff --git a/gcc/testsuite/c-c++-common/torture/strub-ptrfn1.c b/gcc/testsuite/c-c++-common/torture/strub-ptrfn1.c new file mode 100644 index 0000000000000..b4a7f3992bbaa --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-ptrfn1.c @@ -0,0 +1,10 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict" } */ + +typedef void ft (void); +typedef void ft2 (int, int); +extern ft __attribute__ ((__strub__)) fnac; + +ft * f (void) { + return fnac; /* { dg-message "incompatible|invalid conversion" } */ +} diff --git a/gcc/testsuite/c-c++-common/torture/strub-ptrfn2.c b/gcc/testsuite/c-c++-common/torture/strub-ptrfn2.c new file mode 100644 index 0000000000000..d9d2c0caec42d --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-ptrfn2.c @@ -0,0 +1,55 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=relaxed -Wpedantic" } */ + +/* C++ does not warn about the partial incompatibilities. + + The d_p () calls are actually rejected, even in C++, but they are XFAILed + here because we don't get far enough in the compilation as to observe them, + because the incompatibilities are errors without -fpermissive. + strub-ptrfn3.c uses -fpermissive to check those. + */ + +extern int __attribute__ ((strub ("callable"))) bac (void); +extern int __attribute__ ((strub ("disabled"))) bad (void); +extern int __attribute__ ((strub ("internal"))) bar (void); +extern int __attribute__ ((strub ("at-calls"))) bal (void); + +void __attribute__ ((strub)) +bap (void) +{ + int __attribute__ ((strub ("disabled"))) (*d_p) (void) = bad; + int __attribute__ ((strub ("callable"))) (*c_p) (void) = bac; + int __attribute__ ((strub ("at-calls"))) (*a_p) (void) = bal; + + d_p = bac; /* { dg-warning "not quite compatible" "" { xfail c++ } } */ + c_p = bad; /* { dg-warning "not quite compatible" "" { xfail c++ } } */ + c_p = bar; /* { dg-warning "not quite compatible" "" { xfail c++ } } */ + c_p = bal; /* { dg-message "incompatible|invalid conversion" } */ + a_p = bac; /* { dg-message "incompatible|invalid conversion" } */ + + d_p (); /* { dg-error "indirect non-.strub. call in .strub. context" "" { xfail c++ } } */ + c_p (); + a_p (); +} + +void __attribute__ ((strub)) +baP (void) +{ + typedef int __attribute__ ((strub ("disabled"))) d_fn_t (void); + typedef int __attribute__ ((strub ("callable"))) c_fn_t (void); + typedef int __attribute__ ((strub ("at-calls"))) a_fn_t (void); + + d_fn_t *d_p = bad; + c_fn_t *c_p = bac; + a_fn_t *a_p = bal; + + d_p = bac; /* { dg-warning "not quite compatible" "" { xfail c++ } } */ + c_p = bad; /* { dg-warning "not quite compatible" "" { xfail c++ } } */ + c_p = bar; /* { dg-warning "not quite compatible" "" { xfail c++ } } */ + c_p = bal; /* { dg-message "incompatible|invalid conversion" } */ + a_p = bac; /* { dg-message "incompatible|invalid conversion" } */ + + d_p (); /* { dg-error "indirect non-.strub. call in .strub. context" "" { xfail c++ } } */ + c_p (); + a_p (); +} diff --git a/gcc/testsuite/c-c++-common/torture/strub-ptrfn3.c b/gcc/testsuite/c-c++-common/torture/strub-ptrfn3.c new file mode 100644 index 0000000000000..e1f179e160e5c --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-ptrfn3.c @@ -0,0 +1,50 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=relaxed -Wpedantic -fpermissive" } */ +/* { dg-prune-output "command-line option .-fpermissive." } */ + +/* See strub-ptrfn2.c. */ + +extern int __attribute__ ((strub ("callable"))) bac (void); +extern int __attribute__ ((strub ("disabled"))) bad (void); +extern int __attribute__ ((strub ("internal"))) bar (void); +extern int __attribute__ ((strub ("at-calls"))) bal (void); + +void __attribute__ ((strub)) +bap (void) +{ + int __attribute__ ((strub ("disabled"))) (*d_p) (void) = bad; + int __attribute__ ((strub ("callable"))) (*c_p) (void) = bac; + int __attribute__ ((strub ("at-calls"))) (*a_p) (void) = bal; + + d_p = bac; /* { dg-warning "not quite compatible" "" { xfail c++ } } */ + c_p = bad; /* { dg-warning "not quite compatible" "" { xfail c++ } } */ + c_p = bar; /* { dg-warning "not quite compatible" "" { xfail c++ } } */ + c_p = bal; /* { dg-message "incompatible|invalid conversion" } */ + a_p = bac; /* { dg-message "incompatible|invalid conversion" } */ + + d_p (); /* { dg-error "indirect non-.strub. call in .strub. context" } */ + c_p (); + a_p (); +} + +void __attribute__ ((strub)) +baP (void) +{ + typedef int __attribute__ ((strub ("disabled"))) d_fn_t (void); + typedef int __attribute__ ((strub ("callable"))) c_fn_t (void); + typedef int __attribute__ ((strub ("at-calls"))) a_fn_t (void); + + d_fn_t *d_p = bad; + c_fn_t *c_p = bac; + a_fn_t *a_p = bal; + + d_p = bac; /* { dg-warning "not quite compatible" "" { xfail c++ } } */ + c_p = bad; /* { dg-warning "not quite compatible" "" { xfail c++ } } */ + c_p = bar; /* { dg-warning "not quite compatible" "" { xfail c++ } } */ + c_p = bal; /* { dg-message "incompatible|invalid conversion" } */ + a_p = bac; /* { dg-message "incompatible|invalid conversion" } */ + + d_p (); /* { dg-error "indirect non-.strub. call in .strub. context" } */ + c_p (); + a_p (); +} diff --git a/gcc/testsuite/c-c++-common/torture/strub-ptrfn4.c b/gcc/testsuite/c-c++-common/torture/strub-ptrfn4.c new file mode 100644 index 0000000000000..70b558afad040 --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-ptrfn4.c @@ -0,0 +1,43 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=relaxed" } */ + +/* This is strub-ptrfn2.c without -Wpedantic. + + Even C doesn't report the (not-quite-)compatible conversions without it. */ + +extern int __attribute__ ((strub ("callable"))) bac (void); +extern int __attribute__ ((strub ("disabled"))) bad (void); +extern int __attribute__ ((strub ("internal"))) bar (void); +extern int __attribute__ ((strub ("at-calls"))) bal (void); + +void __attribute__ ((strub)) +bap (void) +{ + int __attribute__ ((strub ("disabled"))) (*d_p) (void) = bad; + int __attribute__ ((strub ("callable"))) (*c_p) (void) = bac; + int __attribute__ ((strub ("at-calls"))) (*a_p) (void) = bal; + + d_p = bac; + c_p = bad; + c_p = bar; + c_p = bal; /* { dg-message "incompatible|invalid conversion" } */ + a_p = bac; /* { dg-message "incompatible|invalid conversion" } */ +} + +void __attribute__ ((strub)) +baP (void) +{ + typedef int __attribute__ ((strub ("disabled"))) d_fn_t (void); + typedef int __attribute__ ((strub ("callable"))) c_fn_t (void); + typedef int __attribute__ ((strub ("at-calls"))) a_fn_t (void); + + d_fn_t *d_p = bad; + c_fn_t *c_p = bac; + a_fn_t *a_p = bal; + + d_p = bac; + c_p = bad; + c_p = bar; + c_p = bal; /* { dg-message "incompatible|invalid conversion" } */ + a_p = bac; /* { dg-message "incompatible|invalid conversion" } */ +} diff --git a/gcc/testsuite/c-c++-common/torture/strub-pure1.c b/gcc/testsuite/c-c++-common/torture/strub-pure1.c new file mode 100644 index 0000000000000..a262a086837b2 --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-pure1.c @@ -0,0 +1,18 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +/* Check that, along with a strub pure function call, we issue an asm statement + to make sure the watermark passed to it is not assumed to be unchanged. */ + +int __attribute__ ((__strub__, __pure__)) +f() { + static int i; /* Stop it from being detected as const. */ + return i; +} + +int +g() { + return f(); +} + +/* { dg-final { scan-ipa-dump-times "__asm__" 1 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/torture/strub-pure2.c b/gcc/testsuite/c-c++-common/torture/strub-pure2.c new file mode 100644 index 0000000000000..4c4bd50c209a0 --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-pure2.c @@ -0,0 +1,22 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +/* Check that, along with a strub implicitly-pure function call, we issue an asm + statement to make sure the watermark passed to it is not assumed to be + unchanged. */ + +int __attribute__ ((__strub__)) +#if ! __OPTIMIZE__ /* At -O0, implicit pure detection doesn't run. */ +__attribute__ ((__pure__)) +#endif +f() { + static int i; /* Stop it from being detected as const. */ + return i; +} + +int +g() { + return f(); +} + +/* { dg-final { scan-ipa-dump-times "__asm__" 1 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/torture/strub-pure3.c b/gcc/testsuite/c-c++-common/torture/strub-pure3.c new file mode 100644 index 0000000000000..ce195c6b1f1b6 --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-pure3.c @@ -0,0 +1,13 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +/* Check that, along with a strub pure wrapping call, we issue an asm statement + to make sure the watermark passed to it is not assumed to be unchanged. */ + +int __attribute__ ((__strub__ ("internal"), __pure__)) +f() { + static int i; /* Stop it from being detected as const. */ + return i; +} + +/* { dg-final { scan-ipa-dump-times "__asm__" 1 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/torture/strub-pure4.c b/gcc/testsuite/c-c++-common/torture/strub-pure4.c new file mode 100644 index 0000000000000..75cd54ccb5b5d --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-pure4.c @@ -0,0 +1,17 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +/* Check that, along with a strub implicitly-pure wrapping call, we issue an asm + statement to make sure the watermark passed to it is not assumed to be + unchanged. */ + +int __attribute__ ((__strub__ ("internal"))) +#if ! __OPTIMIZE__ /* At -O0, implicit pure detection doesn't run. */ +__attribute__ ((__pure__)) +#endif +f() { + static int i; /* Stop it from being detected as const. */ + return i; +} + +/* { dg-final { scan-ipa-dump-times "__asm__" 1 "strub" } } */ diff --git a/gcc/testsuite/c-c++-common/torture/strub-run1.c b/gcc/testsuite/c-c++-common/torture/strub-run1.c new file mode 100644 index 0000000000000..c596066a045eb --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-run1.c @@ -0,0 +1,85 @@ +/* { dg-do run } */ +/* { dg-options "-fstrub=strict" } */ + +/* Check that a non-strub function leaves a string behind in the stack, and that + equivalent strub functions don't. */ + +const char test_string[] = "\x55\xde\xad\xbe\xef\xc0\x1d\xca\xfe\x55\xaa"; + +static inline __attribute__ ((__always_inline__, __strub__ ("callable"))) +char * +leak_string (void) +{ + /* We use this variable to avoid any stack red zone. Stack scrubbing covers + it, but __builtin_stack_address, that we take as a reference, doesn't, so + if e.g. callable() were to store the string in the red zone, we wouldn't + find it because it would be outside the range we searched. */ + typedef void __attribute__ ((__strub__ ("callable"))) callable_t (char *); + callable_t *f = 0; + + char s[sizeof (test_string)]; + __builtin_strcpy (s, test_string); + asm ("" : "+m" (s), "+r" (f)); + + if (__builtin_expect (!f, 1)) + return (char *) __builtin_stack_address (); + + f (s); + return 0; +} + +static inline __attribute__ ((__always_inline__)) +int +look_for_string (char *e) +{ + char *p = (char *) __builtin_stack_address (); + + if (p == e) + __builtin_abort (); + + if (p > e) + { + char *q = p; + p = e; + e = q; + } + + for (char *re = e - sizeof (test_string); p < re; p++) + for (int i = 0; p[i] == test_string[i]; i++) + if (i == sizeof (test_string) - 1) + return i; + + return 0; +} + +static __attribute__ ((__noinline__, __noclone__)) +char * +callable () +{ + return leak_string (); +} + +static __attribute__ ((__strub__ ("at-calls"))) +char * +at_calls () +{ + return leak_string (); +} + +static __attribute__ ((__strub__ ("internal"))) +char * +internal () +{ + return leak_string (); +} + +int main () +{ + if (!look_for_string (callable ())) + __builtin_abort (); + if (look_for_string (at_calls ())) + __builtin_abort (); + if (look_for_string (internal ())) + __builtin_abort (); + __builtin_exit (0); +} diff --git a/gcc/testsuite/c-c++-common/torture/strub-run2.c b/gcc/testsuite/c-c++-common/torture/strub-run2.c new file mode 100644 index 0000000000000..1fdba214a07f9 --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-run2.c @@ -0,0 +1,75 @@ +/* { dg-do run } */ +/* { dg-options "-fstrub=strict" } */ + +/* Check that a non-strub function leaves a string behind in the stack, and that + equivalent strub functions don't. */ + +const char test_string[] = "\x55\xde\xad\xbe\xef\xc0\x1d\xca\xfe\x55\xaa"; + +static inline __attribute__ ((__always_inline__, __strub__ ("callable"))) +char * +leak_string (void) +{ + int len = sizeof (test_string); + asm ("" : "+rm" (len)); + char s[len]; + __builtin_strcpy (s, test_string); + asm ("" : "+m" (s)); + return (char *) __builtin_stack_address (); +} + +static inline __attribute__ ((__always_inline__)) +int +look_for_string (char *e) +{ + char *p = (char *) __builtin_stack_address (); + + if (p == e) + __builtin_abort (); + + if (p > e) + { + char *q = p; + p = e; + e = q; + } + + for (char *re = e - sizeof (test_string); p < re; p++) + for (int i = 0; p[i] == test_string[i]; i++) + if (i == sizeof (test_string) - 1) + return i; + + return 0; +} + +static __attribute__ ((__noinline__, __noclone__)) +char * +callable () +{ + return leak_string (); +} + +static __attribute__ ((__strub__ ("at-calls"))) +char * +at_calls () +{ + return leak_string (); +} + +static __attribute__ ((__strub__ ("internal"))) +char * +internal () +{ + return leak_string (); +} + +int main () +{ + if (!look_for_string (callable ())) + __builtin_abort (); + if (look_for_string (at_calls ())) + __builtin_abort (); + if (look_for_string (internal ())) + __builtin_abort (); + __builtin_exit (0); +} diff --git a/gcc/testsuite/c-c++-common/torture/strub-run3.c b/gcc/testsuite/c-c++-common/torture/strub-run3.c new file mode 100644 index 0000000000000..afbc2cc9ab484 --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-run3.c @@ -0,0 +1,75 @@ +/* { dg-do run } */ +/* { dg-options "-fstrub=strict" } */ +/* { dg-require-effective-target alloca } */ + +/* Check that a non-strub function leaves a string behind in the stack, and that + equivalent strub functions don't. */ + +const char test_string[] = "\x55\xde\xad\xbe\xef\xc0\x1d\xca\xfe\x55\xaa"; + +static inline __attribute__ ((__always_inline__, __strub__ ("callable"))) +char * +leak_string (void) +{ + int len = sizeof (test_string); + char *s = (char *) __builtin_alloca (len); + __builtin_strcpy (s, test_string); + asm ("" : "+m" (s)); + return (char *) __builtin_stack_address (); +} + +static inline __attribute__ ((__always_inline__)) +int +look_for_string (char *e) +{ + char *p = (char *) __builtin_stack_address (); + + if (p == e) + __builtin_abort (); + + if (p > e) + { + char *q = p; + p = e; + e = q; + } + + for (char *re = e - sizeof (test_string); p < re; p++) + for (int i = 0; p[i] == test_string[i]; i++) + if (i == sizeof (test_string) - 1) + return i; + + return 0; +} + +static __attribute__ ((__noinline__, __noclone__)) +char * +callable () +{ + return leak_string (); +} + +static __attribute__ ((__strub__ ("at-calls"))) +char * +at_calls () +{ + return leak_string (); +} + +static __attribute__ ((__strub__ ("internal"))) +char * +internal () +{ + return leak_string (); +} + +int main () +{ + if (!look_for_string (callable ())) + __builtin_abort (); + if (look_for_string (at_calls ())) + __builtin_abort (); + if (look_for_string (internal ())) + __builtin_abort (); + __builtin_exit (0); +} diff --git a/gcc/testsuite/c-c++-common/torture/strub-run4.c b/gcc/testsuite/c-c++-common/torture/strub-run4.c new file mode 100644 index 0000000000000..5300f1d330b87 --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-run4.c @@ -0,0 +1,101 @@ +/* { dg-do run } */ +/* { dg-options "-fstrub=all" } */ +/* { dg-require-effective-target alloca } */ + +/* Check that multi-level, multi-inlined functions still get cleaned up as + expected, without overwriting temporary stack allocations while they should + still be available. */ + +#ifndef ATTR_STRUB_AT_CALLS +# define ATTR_STRUB_AT_CALLS /* Defined in strub-run4d.c. */ +#endif + +const char test_string[] = "\x55\xde\xad\xbe\xef\xc0\x1d\xca\xfe\x55\xaa"; + +static inline __attribute__ ((__always_inline__)) +char * +leak_string (void) +{ + int __attribute__ ((__strub__)) len = 512; + asm ("" : "+r" (len)); + char s[len]; + __builtin_strcpy (s, test_string); + __builtin_strcpy (s + len - sizeof (test_string), test_string); + asm ("" : "+m" (s)); + return (char *) __builtin_stack_address (); +} + +static inline __attribute__ ((__always_inline__)) +int +look_for_string (char *e) +{ + char *p = (char *) __builtin_stack_address (); + + if (p == e) + __builtin_abort (); + + if (p > e) + { + char *q = p; + p = e; + e = q; + } + + for (char *re = e - sizeof (test_string); p < re; p++) + for (int i = 0; p[i] == test_string[i]; i++) + if (i == sizeof (test_string) - 1) + return i; + + return 0; +} + +static inline ATTR_STRUB_AT_CALLS +char * +innermost () +{ + int __attribute__ ((__strub__)) len = 512; + asm ("" : "+r" (len)); + char s[len]; + __builtin_strcpy (s, test_string); + __builtin_strcpy (s + len - sizeof (test_string), test_string); + asm ("" : "+m" (s)); + char *ret = leak_string (); + if (__builtin_strcmp (s, test_string) != 0) + __builtin_abort (); + if (__builtin_strcmp (s + len - sizeof (test_string), test_string) != 0) + __builtin_abort (); + return ret; +} + +static inline ATTR_STRUB_AT_CALLS +char * +intermediate () +{ + int __attribute__ ((__strub__)) len = 512; + asm ("" : "+r" (len)); + char s[len]; + __builtin_strcpy (s, test_string); + __builtin_strcpy (s + len - sizeof (test_string), test_string); + asm ("" : "+m" (s)); + char *ret = innermost (); + if (__builtin_strcmp (s, test_string) != 0) + __builtin_abort (); + if (__builtin_strcmp (s + len - sizeof (test_string), test_string) != 0) + __builtin_abort (); + return ret; +} + +static inline __attribute__ ((__strub__ ("internal"))) +char * +internal () +{ + return intermediate (); +} + +int __attribute__ ((__strub__ ("disabled"))) +main () +{ + if (look_for_string (internal ())) + __builtin_abort (); + __builtin_exit (0); +} diff --git a/gcc/testsuite/c-c++-common/torture/strub-run4c.c b/gcc/testsuite/c-c++-common/torture/strub-run4c.c new file mode 100644 index 0000000000000..57f9baf758ded --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-run4c.c @@ -0,0 +1,5 @@ +/* { dg-do run } */ +/* { dg-options "-fstrub=at-calls" } */ +/* { dg-require-effective-target alloca } */ + +#include "strub-run4.c" diff --git a/gcc/testsuite/c-c++-common/torture/strub-run4d.c b/gcc/testsuite/c-c++-common/torture/strub-run4d.c new file mode 100644 index 0000000000000..08de3f1c3b17c --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-run4d.c @@ -0,0 +1,7 @@ +/* { dg-do run } */ +/* { dg-options "-fstrub=strict" } */ +/* { dg-require-effective-target alloca } */ + +#define ATTR_STRUB_AT_CALLS __attribute__ ((__strub__ ("at-calls"))) + +#include "strub-run4.c" diff --git a/gcc/testsuite/c-c++-common/torture/strub-run4i.c b/gcc/testsuite/c-c++-common/torture/strub-run4i.c new file mode 100644 index 0000000000000..459f6886c5499 --- /dev/null +++ b/gcc/testsuite/c-c++-common/torture/strub-run4i.c @@ -0,0 +1,5 @@ +/* { dg-do run } */ +/* { dg-options "-fstrub=internal" } */ +/* { dg-require-effective-target alloca } */ + +#include "strub-run4.c" diff --git a/gcc/testsuite/g++.dg/strub-run1.C b/gcc/testsuite/g++.dg/strub-run1.C new file mode 100644 index 0000000000000..0d367fb83d09d --- /dev/null +++ b/gcc/testsuite/g++.dg/strub-run1.C @@ -0,0 +1,19 @@ +// { dg-do run } +// { dg-options "-fstrub=internal" } + +// Check that we don't get extra copies. + +struct T { + T &self; + void check () const { if (&self != this) __builtin_abort (); } + T() : self (*this) { check (); } + T(const T& ck) : self (*this) { ck.check (); check (); } + ~T() { check (); } +}; + +T foo (T q) { q.check (); return T(); } +T bar (T p) { p.check (); return foo (p); } + +int main () { + bar (T()).check (); +} diff --git a/gcc/testsuite/g++.dg/torture/strub-init1.C b/gcc/testsuite/g++.dg/torture/strub-init1.C new file mode 100644 index 0000000000000..c226ab10ff651 --- /dev/null +++ b/gcc/testsuite/g++.dg/torture/strub-init1.C @@ -0,0 +1,13 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +extern int __attribute__((__strub__)) initializer (); + +int f() { + static int x = initializer (); + return x; +} + +/* { dg-final { scan-ipa-dump "strub_enter" "strub" } } */ +/* { dg-final { scan-ipa-dump "strub_leave" "strub" } } */ +/* { dg-final { scan-ipa-dump-not "strub_update" "strub" } } */ diff --git a/gcc/testsuite/g++.dg/torture/strub-init2.C b/gcc/testsuite/g++.dg/torture/strub-init2.C new file mode 100644 index 0000000000000..a7911f1fa7212 --- /dev/null +++ b/gcc/testsuite/g++.dg/torture/strub-init2.C @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +extern int __attribute__((__strub__)) initializer (); + +static int x = initializer (); + +int f() { + return x; +} + +/* { dg-final { scan-ipa-dump "strub_enter" "strub" } } */ +/* { dg-final { scan-ipa-dump "strub_leave" "strub" } } */ +/* { dg-final { scan-ipa-dump-not "strub_update" "strub" } } */ diff --git a/gcc/testsuite/g++.dg/torture/strub-init3.C b/gcc/testsuite/g++.dg/torture/strub-init3.C new file mode 100644 index 0000000000000..6ebebcd01e8ea --- /dev/null +++ b/gcc/testsuite/g++.dg/torture/strub-init3.C @@ -0,0 +1,13 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=strict -fdump-ipa-strub" } */ + +extern int __attribute__((__strub__)) initializer (); + +int f() { + int x = initializer (); + return x; +} + +/* { dg-final { scan-ipa-dump "strub_enter" "strub" } } */ +/* { dg-final { scan-ipa-dump "strub_leave" "strub" } } */ +/* { dg-final { scan-ipa-dump-not "strub_update" "strub" } } */ diff --git a/gcc/testsuite/gnat.dg/strub_attr.adb b/gcc/testsuite/gnat.dg/strub_attr.adb new file mode 100644 index 0000000000000..10445d7cf8451 --- /dev/null +++ b/gcc/testsuite/gnat.dg/strub_attr.adb @@ -0,0 +1,37 @@ +-- { dg-do compile } +-- { dg-options "-fstrub=strict -fdump-ipa-strubm -fdump-ipa-strub" } + +package body Strub_Attr is + E : exception; + + procedure P (X : Integer) is + begin + raise E; + end; + + function F (X : Integer) return Integer is + begin + return X * X; + end; + + function G return Integer is (F (X)); + -- function G return Integer is (FP (X)); + -- Calling G would likely raise an exception, because although FP + -- carries the strub at-calls attribute needed to call F, the + -- attribute is dropped from the type used for the call proper. +end Strub_Attr; + +-- { dg-final { scan-ipa-dump-times "\[(\]strub \[(\]internal\[)\]\[)\]" 2 "strubm" } } +-- { dg-final { scan-ipa-dump-times "\[(\]strub \[(\]at-calls\[)\]\[)\]" 0 "strubm" } } +-- { dg-final { scan-ipa-dump-times "\[(\]strub\[)\]" 1 "strubm" } } + +-- { dg-final { scan-ipa-dump-times "strub.watermark_ptr" 6 "strub" } } +-- We have 1 at-calls subprogram (F) and 2 wrapped (P and G). +-- For each of them, there's one match for the wrapped signature, +-- and one for the update call. + +-- { dg-final { scan-ipa-dump-times "strub.watermark" 27 "strub" } } +-- The 6 matches above, plus: +-- 5*2: wm var decl, enter, call, leave and clobber for each wrapper; +-- 2*1: an extra leave and clobber for the exception paths in the wrappers. +-- 7*1: for the F call in G, including EH path. diff --git a/gcc/testsuite/gnat.dg/strub_attr.ads b/gcc/testsuite/gnat.dg/strub_attr.ads new file mode 100644 index 0000000000000..a94c23bf41833 --- /dev/null +++ b/gcc/testsuite/gnat.dg/strub_attr.ads @@ -0,0 +1,12 @@ +package Strub_Attr is + procedure P (X : Integer); + pragma Machine_Attribute (P, "strub", "internal"); + + function F (X : Integer) return Integer; + pragma Machine_Attribute (F, "strub"); + + X : Integer := 0; + pragma Machine_Attribute (X, "strub"); + + function G return Integer; +end Strub_Attr; diff --git a/gcc/testsuite/gnat.dg/strub_ind.adb b/gcc/testsuite/gnat.dg/strub_ind.adb new file mode 100644 index 0000000000000..d08341a23b351 --- /dev/null +++ b/gcc/testsuite/gnat.dg/strub_ind.adb @@ -0,0 +1,44 @@ +-- { dg-do compile } +-- { dg-options "-fstrub=strict -fdump-ipa-strubm" } + +-- This is essentially the same test as strub_attr.adb, +-- but applying attributes to access types as well. +-- That doesn't quite work yet, so we get an error we shouldn't get. + +package body Strub_Ind is + E : exception; + + procedure P (X : Integer) is + begin + raise E; + end; + + function F (X : Integer) return Integer is + begin + return X * X; + end; + + function G return Integer is (FP (X)); -- { dg-bogus "non-.strub." "" { xfail *-*-* } } + -- Calling G would likely raise an exception, because although FP + -- carries the strub at-calls attribute needed to call F, the + -- attribute is dropped from the type used for the call proper. + + + type GT is access function return Integer; + pragma Machine_Attribute (GT, "strub", "at-calls"); + -- The pragma above seems to have no effect. + + GP : GT := G'Access; -- { dg-warning "incompatible" "" { xfail *-*-* } } + pragma Machine_Attribute (GP, "strub", "at-calls"); + -- The pragma above does modify GP's type, + -- but dereferencing it uses an unmodified copy of the type. + -- The initializer should be diagnosed: + -- GT should only reference functions with at-calls strub. + +end Strub_Ind; + +-- { dg-final { scan-ipa-dump-times "\[(\]strub \[(\]internal\[)\]\[)\]" 2 "strubm" } } +-- { dg-final { scan-ipa-dump-times "\[(\]strub \[(\]at-calls\[)\]\[)\]" 0 "strubm" } } +-- { dg-final { scan-ipa-dump-times "\[(\]strub\[)\]" 1 "strubm" } } + +-- No "strub" dump checking because of the bogus error above. diff --git a/gcc/testsuite/gnat.dg/strub_ind.ads b/gcc/testsuite/gnat.dg/strub_ind.ads new file mode 100644 index 0000000000000..53dede60eacdd --- /dev/null +++ b/gcc/testsuite/gnat.dg/strub_ind.ads @@ -0,0 +1,23 @@ +package Strub_Ind is + procedure P (X : Integer); + pragma Machine_Attribute (P, "strub", "internal"); + + function F (X : Integer) return Integer; + pragma Machine_Attribute (F, "strub"); + + X : Integer := 0; + pragma Machine_Attribute (X, "strub"); + + function G return Integer; + + type FT is access function (X : Integer) return Integer; + pragma Machine_Attribute (FT, "strub", "at-calls"); + -- The pragma above seems to get discarded in GNAT; Gigi doesn't see it. + + FP : FT := F'Access; + pragma Machine_Attribute (FP, "strub", "at-calls"); + -- The pragma above does modify FP's type, + -- but a call with it gets it converted to its Ada type, + -- that is cached by the translator as the unmodified type. + +end Strub_Ind; diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c index 61b53913e0b30..9b01f2bb01ba7 100644 --- a/gcc/tree-cfg.c +++ b/gcc/tree-cfg.c @@ -5620,6 +5620,7 @@ gimple_verify_flow_info (void) { gimple *stmt = gsi_stmt (gsi); + /* Do NOT disregard debug stmts after found_ctrl_stmt. */ if (found_ctrl_stmt) { error ("control flow in the middle of basic block %d", diff --git a/gcc/tree-pass.h b/gcc/tree-pass.h index 83941bc0ceef0..df4abdf144928 100644 --- a/gcc/tree-pass.h +++ b/gcc/tree-pass.h @@ -497,8 +497,9 @@ extern gimple_opt_pass *make_pass_adjust_alignment (gcc::context *ctxt); /* IPA Passes */ extern simple_ipa_opt_pass *make_pass_ipa_lower_emutls (gcc::context *ctxt); -extern simple_ipa_opt_pass - *make_pass_ipa_function_and_variable_visibility (gcc::context *ctxt); +extern simple_ipa_opt_pass *make_pass_ipa_function_and_variable_visibility (gcc::context *ctxt); +extern simple_ipa_opt_pass *make_pass_ipa_strub_mode (gcc::context *ctxt); +extern simple_ipa_opt_pass *make_pass_ipa_strub (gcc::context *ctxt); extern simple_ipa_opt_pass *make_pass_ipa_tree_profile (gcc::context *ctxt); extern simple_ipa_opt_pass *make_pass_ipa_auto_profile (gcc::context *ctxt); diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c index 70ce6a4d5b8d1..dca5233cc7bb6 100644 --- a/gcc/tree-ssa-ccp.c +++ b/gcc/tree-ssa-ccp.c @@ -3050,7 +3050,9 @@ optimize_stack_restore (gimple_stmt_iterator i) if (!callee || !fndecl_built_in_p (callee, BUILT_IN_NORMAL) /* All regular builtins are ok, just obviously not alloca. */ - || ALLOCA_FUNCTION_CODE_P (DECL_FUNCTION_CODE (callee))) + || ALLOCA_FUNCTION_CODE_P (DECL_FUNCTION_CODE (callee)) + /* Do not remove stack updates before strub leave. */ + || fndecl_built_in_p (callee, BUILT_IN___STRUB_LEAVE)) return NULL_TREE; if (fndecl_built_in_p (callee, BUILT_IN_STACK_RESTORE)) diff --git a/libgcc/Makefile.in b/libgcc/Makefile.in index 7ec9758455445..c4ee6701cb33b 100644 --- a/libgcc/Makefile.in +++ b/libgcc/Makefile.in @@ -428,7 +428,7 @@ ifneq ($(enable_shared),yes) iterator = $(patsubst %,$(srcdir)/static-object.mk,$(iter-items)) endif -LIB2ADD += enable-execute-stack.c +LIB2ADD += enable-execute-stack.c $(srcdir)/strub.c # While emutls.c has nothing to do with EH, it is in LIB2ADDEH* # instead of LIB2ADD because that's the way to be sure on some targets diff --git a/libgcc/libgcc2.h b/libgcc/libgcc2.h index 1819ff3ac3d03..857091e65c82b 100644 --- a/libgcc/libgcc2.h +++ b/libgcc/libgcc2.h @@ -532,6 +532,10 @@ extern int __parityDI2 (UDWtype); extern void __enable_execute_stack (void *); +extern void __strub_enter (void **); +extern void __strub_update (void**); +extern void __strub_leave (void **); + #ifndef HIDE_EXPORTS #pragma GCC visibility pop #endif diff --git a/libgcc/strub.c b/libgcc/strub.c new file mode 100644 index 0000000000000..7c58deee1e602 --- /dev/null +++ b/libgcc/strub.c @@ -0,0 +1,112 @@ +/* Stack scrubbing infrastructure + Copyright (C) 2021 Free Software Foundation, Inc. + Contributed by Alexandre Oliva + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 3, or (at your option) any later +version. + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +Under Section 7 of GPL version 3, you are granted additional +permissions described in the GCC Runtime Library Exception, version +3.1, as published by the Free Software Foundation. + +You should have received a copy of the GNU General Public License and +a copy of the GCC Runtime Library Exception along with this program; +see the files COPYING3 and COPYING.RUNTIME respectively. If not, see +. */ + +#include "tconfig.h" +#include "tsystem.h" +#include "coretypes.h" +#include "tm.h" +#include "libgcc_tm.h" +#include "libgcc2.h" + +#ifndef STACK_GROWS_DOWNWARD +# define TOPS > +#else +# define TOPS < +#endif + +#define ATTRIBUTE_STRUB_CALLABLE __attribute__ ((__strub__ ("callable"))) + +/* Enter a stack scrubbing context, initializing the watermark to the caller's + stack address. */ +void ATTRIBUTE_STRUB_CALLABLE +__strub_enter (void **watermark) +{ + *watermark = __builtin_frame_address (0); +} + +/* Update the watermark within a stack scrubbing context with the current stack + pointer. */ +void ATTRIBUTE_STRUB_CALLABLE +__strub_update (void **watermark) +{ + void *sp = __builtin_frame_address (0); + + if (sp TOPS *watermark) + *watermark = sp; +} + +#ifndef TARGET_STRUB_USE_DYNAMIC_ARRAY +# define TARGET_STRUB_DONT_USE_DYNAMIC_ARRAY 1 +#endif + +#ifndef TARGET_STRUB_DONT_USE_DYNAMIC_ARRAY +# ifdef TARGET_STRUB_MAY_USE_MEMSET +# define TARGET_STRUB_DONT_USE_DYNAMIC_ARRAY 1 +# else +# define TARGET_STRUB_MAY_USE_MEMSET 1 +# endif +#endif + +/* Leave a stack scrubbing context, restoring and updating SAVED, and + clearing the stack between top and watermark. */ +void ATTRIBUTE_STRUB_CALLABLE +#if ! TARGET_STRUB_MAY_USE_MEMSET +__attribute__ ((__optimize__ ("-fno-tree-loop-distribute-patterns"))) +#endif +__strub_leave (void **mark) +{ + void *sp = __builtin_stack_address (); + + void **base, **end; +#ifndef STACK_GROWS_DOWNWARD + base = sp; + end = *mark; +#else + base = *mark; + end = sp; +#endif + + ptrdiff_t len = end - base; + if (len <= 0) + return; + +#if ! TARGET_STRUB_DONT_USE_DYNAMIC_ARRAY + /* Allocate a dynamically-sized array covering the desired range, so that we + can safely call memset on it. */ + void *ptr[len]; + base = &ptr[0]; + end = &ptr[len]; +#else + void **ptr = end; +#endif /* TARGET_STRUB_DONT_USE_DYNAMIC_ARRAY */ + + /* ldist turns this into a memset. Without the dynamic array above, that call + is likely unsafe: possibly tail-called, and likely scribbling over its own + stack frame. */ + while (base < end) + *base++ = 0; + + asm ("" : : "m" (ptr)); +}