@@ -47,6 +47,7 @@ with_aix_soname = @with_aix_soname@
solaris_ld_v2_maps = @solaris_ld_v2_maps@
enable_execute_stack = @enable_execute_stack@
unwind_header = @unwind_header@
+md_unwind_def_header = @md_unwind_def_header@
md_unwind_header = @md_unwind_header@
sfp_machine_header = @sfp_machine_header@
thread_header = @thread_header@
@@ -358,13 +359,16 @@ SHLIBUNWIND_INSTALL =
# Create links to files specified in config.host.
-LIBGCC_LINKS = enable-execute-stack.c unwind.h md-unwind-support.h \
+LIBGCC_LINKS = enable-execute-stack.c \
+ unwind.h md-unwind-def.h md-unwind-support.h \
sfp-machine.h gthr-default.h
enable-execute-stack.c: $(srcdir)/$(enable_execute_stack)
-$(LN_S) $< $@
unwind.h: $(srcdir)/$(unwind_header)
-$(LN_S) $< $@
+md-unwind-def.h: $(srcdir)/config/$(md_unwind_def_header)
+ -$(LN_S) $< $@
md-unwind-support.h: $(srcdir)/config/$(md_unwind_header)
-$(LN_S) $< $@
sfp-machine.h: $(srcdir)/config/$(sfp_machine_header)
@@ -51,8 +51,10 @@
# If either is set, EXTRA_PARTS and
# EXTRA_MULTILIB_PARTS inherited from the GCC
# subdirectory will be ignored.
-# md_unwind_header The name of a header file defining
-# MD_FALLBACK_FRAME_STATE_FOR.
+# md_unwind_def_header The name of a header file defining architecture
+# -specific frame information types for unwinding.
+# md_unwind_header The name of a header file defining architecture
+# -specific handlers used in the unwinder.
# sfp_machine_header The name of a sfp-machine.h header file for soft-fp.
# Defaults to "$cpu_type/sfp-machine.h" if it exists,
# no-sfp-machine.h otherwise.
@@ -72,6 +74,7 @@ extra_parts=
tmake_file=
tm_file=
tm_define=
+md_unwind_def_header=no-unwind.h
md_unwind_header=no-unwind.h
unwind_header=unwind-generic.h
@@ -403,6 +406,7 @@ aarch64*-*-elf | aarch64*-*-rtems*)
tmake_file="${tmake_file} ${cpu_type}/t-lse t-slibgcc-libgcc"
tmake_file="${tmake_file} ${cpu_type}/t-softfp t-softfp t-crtfm"
tmake_file="${tmake_file} t-dfprules"
+ md_unwind_def_header=aarch64/aarch64-unwind-def.h
md_unwind_header=aarch64/aarch64-unwind.h
;;
aarch64*-*-freebsd*)
@@ -411,6 +415,7 @@ aarch64*-*-freebsd*)
tmake_file="${tmake_file} ${cpu_type}/t-lse t-slibgcc-libgcc"
tmake_file="${tmake_file} ${cpu_type}/t-softfp t-softfp t-crtfm"
tmake_file="${tmake_file} t-dfprules"
+ md_unwind_def_header=aarch64/aarch64-unwind-def.h
md_unwind_header=aarch64/freebsd-unwind.h
;;
aarch64*-*-netbsd*)
@@ -418,6 +423,7 @@ aarch64*-*-netbsd*)
tmake_file="${tmake_file} ${cpu_type}/t-aarch64"
tmake_file="${tmake_file} ${cpu_type}/t-softfp t-softfp t-crtfm"
tmake_file="${tmake_file} t-dfprules"
+ md_unwind_def_header=aarch64/aarch64-unwind-def.h
md_unwind_header=aarch64/aarch64-unwind.h
;;
aarch64*-*-fuchsia*)
@@ -428,6 +434,7 @@ aarch64*-*-fuchsia*)
;;
aarch64*-*-linux*)
extra_parts="$extra_parts crtfastmath.o"
+ md_unwind_def_header=aarch64/aarch64-unwind-def.h
md_unwind_header=aarch64/linux-unwind.h
tmake_file="${tmake_file} ${cpu_type}/t-aarch64"
tmake_file="${tmake_file} ${cpu_type}/t-lse t-slibgcc-libgcc"
@@ -437,6 +444,7 @@ aarch64*-*-linux*)
;;
aarch64*-*-gnu*)
extra_parts="$extra_parts crtfastmath.o"
+ md_unwind_def_header=aarch64/aarch64-unwind-def.h
md_unwind_header=aarch64/gnu-unwind.h
tmake_file="${tmake_file} ${cpu_type}/t-aarch64"
tmake_file="${tmake_file} ${cpu_type}/t-lse t-slibgcc-libgcc"
@@ -446,6 +454,7 @@ aarch64*-*-gnu*)
;;
aarch64*-*-vxworks7*)
extra_parts="$extra_parts crtfastmath.o"
+ md_unwind_def_header=aarch64/aarch64-unwind-def.h
md_unwind_header=aarch64/aarch64-unwind.h
tmake_file="${tmake_file} ${cpu_type}/t-aarch64"
tmake_file="${tmake_file} ${cpu_type}/t-lse"
new file mode 100644
@@ -0,0 +1,41 @@
+/* Copyright (C) 2024 Free Software Foundation, Inc.
+ Contributed by Arm Ltd.
+
+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
+<http://www.gnu.org/licenses/>. */
+
+#if !defined (AARCH64_UNWIND_DEF_H) && !defined (__ILP32__)
+#define AARCH64_UNWIND_DEF_H
+
+/* The key used to sign a function's return address. */
+typedef enum {
+ AARCH64_PAUTH_KEY_A,
+ AARCH64_PAUTH_KEY_B,
+} __attribute__((packed)) aarch64_pointer_auth_key;
+
+typedef struct
+{
+ aarch64_pointer_auth_key signing_key;
+} _AArch64Ext_Unwind_FrameState;
+
+#define MD_ARCH_FRAME_STATE_T _AArch64Ext_Unwind_FrameState
+
+#endif /* defined AARCH64_UNWIND_DEF_H && defined __ILP32__ */
@@ -25,6 +25,8 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
#if !defined (AARCH64_UNWIND_H) && !defined (__ILP32__)
#define AARCH64_UNWIND_H
+#include "aarch64-unwind-def.h"
+
#include "ansidecl.h"
#include <stdbool.h>
@@ -38,12 +40,6 @@ typedef enum
aarch64_ra_signing_sp = 0x1,
} __attribute__((packed)) aarch64_ra_signing_method_t;
-/* The key used to sign a function's return address. */
-typedef enum {
- AARCH64_PAUTH_KEY_A,
- AARCH64_PAUTH_KEY_B,
-} __attribute__((packed)) aarch64_pointer_auth_key;
-
#define MD_ARCH_EXTENSION_CIE_AUG_HANDLER(fs, aug) \
aarch64_cie_aug_handler (fs, aug)
@@ -100,7 +96,7 @@ aarch64_cie_aug_handler (_Unwind_FrameState *fs, unsigned char aug)
/* AArch64 B-key pointer authentication. */
if (aug == 'B')
{
- fs->regs.signing_key = AARCH64_PAUTH_KEY_B;
+ fs->regs.arch_fs.signing_key = AARCH64_PAUTH_KEY_B;
return true;
}
return false;
@@ -119,7 +115,7 @@ aarch64_arch_extension_frame_init (struct _Unwind_Context *context ATTRIBUTE_UNU
/* By default, DW_CFA_AARCH64_negate_ra_state assumes key A is being used
for signing. This can be overridden by adding 'B' to the augmentation
string. */
- fs->regs.signing_key = AARCH64_PAUTH_KEY_A;
+ fs->regs.arch_fs.signing_key = AARCH64_PAUTH_KEY_A;
/* All registers are initially in state REG_UNSAVED, which indicates that
they inherit register values from the previous frame. However, the
@@ -174,7 +170,7 @@ aarch64_demangle_return_addr (struct _Unwind_Context *context,
if (signing_method == aarch64_ra_signing_sp)
{
_Unwind_Word salt = (_Unwind_Word) context->cfa;
- if (fs->regs.signing_key == AARCH64_PAUTH_KEY_B)
+ if (fs->regs.arch_fs.signing_key == AARCH64_PAUTH_KEY_B)
return __builtin_aarch64_autib1716 (addr, salt);
return __builtin_aarch64_autia1716 (addr, salt);
}
@@ -1,2 +1,3 @@
/* Dummy header for targets without a definition of
- MD_FALLBACK_FRAME_STATE_FOR. */
+ architecture-specific frame information types, or
+ handlers used in the unwinder. */
@@ -727,6 +727,7 @@ AC_SUBST(extra_parts)
AC_SUBST(asm_hidden_op)
AC_SUBST(enable_execute_stack)
AC_SUBST(unwind_header)
+AC_SUBST(md_unwind_def_header)
AC_SUBST(md_unwind_header)
AC_SUBST(sfp_machine_header)
AC_SUBST(thread_header)
@@ -22,6 +22,8 @@
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
+#include "md-unwind-def.h"
+
enum register_rule
{
REG_UNSAVED,
@@ -71,8 +73,8 @@ typedef struct
Note: this information has to be saved in struct frame_state_reg_info
instead of _Unwind_FrameState as DW_CFA_restore_state has to be able to
restore them. */
-#if defined(__aarch64__) && !defined (__ILP32__)
- unsigned char signing_key;
+#if defined(MD_ARCH_FRAME_STATE_T)
+ MD_ARCH_FRAME_STATE_T arch_fs;
#endif
} regs;
This patch provides a new handler MD_ARCH_FRAME_STATE_T to hide an architecture-specific structure containing CIE and FDE data related to DWARF architecture extensions. Hiding the architecture-specific attributes behind a handler has the following benefits: 1. isolating those data from the generic ones in _Unwind_FrameState 2. avoiding casts to custom types. 3. preserving typing information when debugging with GDB, and so facilitating their printing. This approach required to add a new header md-unwind-def.h included at the top of libgcc/unwind-dw2.h, and redirecting to the corresponding architecture header via a symbolic link. An obvious drawback is the increase in complexity with macros, and headers. It also caused a split of architecture definitions between md-unwind-def.h (types definitions used in unwind-dw2.h) and md-unwind.h (local types definitions and handlers implementations). The naming of md-unwind.h with .h extension is a bit misleading as the file is only included in the middle of unwind-dw2.c. Changing this naming would require modification of others backends, which I prefered to abstain from. Overall the benefits are worth the added complexity from my perspective. libgcc/ChangeLog: * Makefile.in: New target for symbolic link to md-unwind-def.h * config.host: New parameter md_unwind_def_header. Set it to aarch64/aarch64-unwind-def.h for AArch64 targets, or no-unwind.h by default. * config/aarch64/aarch64-unwind.h (aarch64_pointer_auth_key): Move to aarch64-unwind-def.h (aarch64_cie_aug_handler): Update. (aarch64_arch_extension_frame_init): Update. (aarch64_demangle_return_addr): Update. * configure.ac: New substitute variable md_unwind_def_header. * unwind-dw2.h (defined): MD_ARCH_FRAME_STATE_T. * config/aarch64/aarch64-unwind-def.h: New file. --- libgcc/Makefile.in | 6 +++- libgcc/config.host | 13 +++++-- libgcc/config/aarch64/aarch64-unwind-def.h | 41 ++++++++++++++++++++++ libgcc/config/aarch64/aarch64-unwind.h | 14 +++----- libgcc/config/no-unwind.h | 3 +- libgcc/configure.ac | 1 + libgcc/unwind-dw2.h | 6 ++-- 7 files changed, 69 insertions(+), 15 deletions(-) create mode 100644 libgcc/config/aarch64/aarch64-unwind-def.h