[09/10] tree-object-size: Dynamic sizes for ADDR_EXPR

Message ID	20211109190137.1107736-10-siddhesh@gotplt.org
State	New
Headers	show Return-Path: <gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org> DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 4E1CD3858020 sender: dreamhost) by relay.mailchannels.net (Postfix) with ESMTPA id 11FFD4022F1; Tue, 9 Nov 2021 19:02:11 +0000 (UTC) sender: siddhesh@gotplt.org) by pdx1-sub0-mail-a306.dreamhost.com (Postfix) with ESMTPSA id 4HpcmK0rcnz1Wh; Tue, 9 Nov 2021 11:02:08 -0800 (PST) From: Siddhesh Poyarekar <siddhesh@gotplt.org> To: gcc-patches@gcc.gnu.org Subject: [PATCH 09/10] tree-object-size: Dynamic sizes for ADDR_EXPR Date: Wed, 10 Nov 2021 00:31:35 +0530 Message-Id: <20211109190137.1107736-10-siddhesh@gotplt.org> In-Reply-To: <20211109190137.1107736-1-siddhesh@gotplt.org> References: <20211109190137.1107736-1-siddhesh@gotplt.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=23.83.212.4; envelope-from=siddhesh@gotplt.org; helo=antelope.elm.relay.mailchannels.net X-Spam_score_int: -19 X-Spam_score: -2.0 X-Spam_bar: -- X-Spam_report: (-2.0 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, RCVD_IN_SBL=0.141, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action Precedence: list Cc: jakub@redhat.com Errors-To: gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org Sender: "Gcc-patches" <gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org>
Series	__builtin_dynamic_object_size \| expand [00/10] __builtin_dynamic_object_size [01/10] tree-object-size: Replace magic numbers with enums [02/10] tree-object-size: Abstract object_sizes array [03/10] tree-object-size: Use tree instead of HOST_WIDE_INT [04/10] tree-object-size: Single pass dependency loop resolution [05/10] __builtin_dynamic_object_size: Recognize builtin [06/10] tree-object-size: Support dynamic sizes in conditions [07/10] tree-object-size: Handle function parameters [08/10] tree-object-size: Handle GIMPLE_CALL [09/10] tree-object-size: Dynamic sizes for ADDR_EXPR [10/10] tree-object-size: Handle dynamic offsets

diff --git a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-0.c b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-0.c index 4ad49a51878..a1db63b2d45 100644 --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-0.c +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-0.c @@ -219,6 +219,60 @@ test_deploop (size_t sz, size_t cond) return __builtin_dynamic_object_size (bin, 0); } +/* Address expressions. */ + +struct dynarray_struct +{ + long a; + char c[16]; + int b; +}; + +size_t +__attribute__ ((noinline)) +test_dynarray_struct (size_t sz, size_t off) +{ + struct dynarray_struct bin[sz]; + + return __builtin_dynamic_object_size (&bin[off].c, 0); +} + +size_t +__attribute__ ((noinline)) +test_dynarray_struct_subobj (size_t sz, size_t off) +{ + struct dynarray_struct bin[sz]; + + return __builtin_dynamic_object_size (&bin[off].c[4], 1); +} + +size_t +__attribute__ ((noinline)) +test_dynarray_struct_subobj2 (size_t sz, size_t off, size_t *objsz) +{ + struct dynarray_struct2 + { + long a; + int b; + char c[sz]; + }; + + struct dynarray_struct2 bin; + + *objsz = sizeof (bin); + + return __builtin_dynamic_object_size (&bin.c[off], 1); +} + +size_t +__attribute__ ((noinline)) +test_substring (size_t sz, size_t off) +{ + char str[sz]; + + return __builtin_dynamic_object_size (&str[off], 0); +} + size_t __attribute__ ((access (__read_write__, 1, 2))) test_parmsz_simple (void *obj, size_t sz) @@ -286,6 +340,23 @@ main (int argc, char **argv) FAIL (); if (test_dynarray (__builtin_strlen (argv[0])) != __builtin_strlen (argv[0])) FAIL (); + if (test_dynarray_struct (42, 4) != + ((42 - 4) * sizeof (struct dynarray_struct) + - __builtin_offsetof (struct dynarray_struct, c))) + FAIL (); + if (test_dynarray_struct (42, 48) != 0) + FAIL (); + if (test_substring (128, 4) != 128 - 4) + FAIL (); + if (test_substring (128, 142) != 0) + FAIL (); + if (test_dynarray_struct_subobj (42, 4) != 16 - 4) + FAIL (); + if (test_dynarray_struct_subobj (42, 48) != 0) + FAIL (); + size_t objsz = 0; + if (test_dynarray_struct_subobj2 (42, 4, &objsz) != objsz - 4 - 12) + FAIL (); if (test_dynarray_cond (0) != 16) FAIL (); if (test_dynarray_cond (1) != 8) diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-1.c b/gcc/testsuite/gcc.dg/builtin-object-size-1.c index 606141f9405..ba5a34c1f8e 100644 --- a/gcc/testsuite/gcc.dg/builtin-object-size-1.c +++ b/gcc/testsuite/gcc.dg/builtin-object-size-1.c @@ -81,30 +81,56 @@ test1 (void *q, int x) r = malloc (30); else r = calloc (2, 16); +#ifdef DYNAMIC_OBJECT_SIZE + if (__builtin_object_size (r, 0) != (x < 20 ? 30 : 2 * 16)) + abort (); +#else /* We may duplicate this test onto the two exit paths. On one path the size will be 32, the other it will be 30. If we don't duplicate this test, then the size will be 32. */ if (__builtin_object_size (r, 0) != 2 * 16 && __builtin_object_size (r, 0) != 30) abort (); +#endif if (x < 20) r = malloc (30); else r = calloc (2, 14); +#ifdef DYNAMIC_OBJECT_SIZE + if (__builtin_object_size (r, 0) != (x < 20 ? 30 : 2 * 14)) + abort (); +#else if (__builtin_object_size (r, 0) != 30) abort (); +#endif if (x < 30) r = malloc (sizeof (a)); else r = &a.a[3]; +#ifdef DYNAMIC_OBJECT_SIZE + if (__builtin_object_size (r, 0) != (x < 30 ? sizeof (a) : sizeof (a) - 3)) + abort (); +#else if (__builtin_object_size (r, 0) != sizeof (a)) abort (); +#endif r = memcpy (r, "a", 2); +#ifdef DYNAMIC_OBJECT_SIZE + if (__builtin_object_size (r, 0) != (x < 30 ? sizeof (a) : sizeof (a) - 3)) + abort (); +#else if (__builtin_object_size (r, 0) != sizeof (a)) abort (); +#endif r = memcpy (r + 2, "b", 2) + 2; +#ifdef DYNAMIC_OBJECT_SIZE + if (__builtin_object_size (r, 0) + != (x < 30 ? sizeof (a) - 4 : sizeof (a) - 7)) + abort (); +#else if (__builtin_object_size (r, 0) != sizeof (a) - 4) abort (); +#endif r = &a.a[4]; r = memset (r, 'a', 2); if (__builtin_object_size (r, 0) @@ -140,14 +166,16 @@ test1 (void *q, int x) abort (); if (__builtin_object_size (var + 10, 0) != x) abort (); + if (__builtin_object_size (&var[5], 0) != x + 5) + abort (); #else if (__builtin_object_size (var, 0) != (size_t) -1) abort (); if (__builtin_object_size (var + 10, 0) != (size_t) -1) abort (); -#endif if (__builtin_object_size (&var[5], 0) != (size_t) -1) abort (); +#endif if (__builtin_object_size (zerol, 0) != 0) abort (); if (__builtin_object_size (&zerol, 0) != 0) diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-2.c b/gcc/testsuite/gcc.dg/builtin-object-size-2.c index 57fd17d5a45..4af30e8c580 100644 --- a/gcc/testsuite/gcc.dg/builtin-object-size-2.c +++ b/gcc/testsuite/gcc.dg/builtin-object-size-2.c @@ -75,30 +75,56 @@ test1 (void *q, int x) r = malloc (30); else r = calloc (2, 16); +#ifdef DYNAMIC_OBJECT_SIZE + if (__builtin_object_size (r, 1) != (x < 20 ? 30 : 2 * 16)) + abort (); +#else /* We may duplicate this test onto the two exit paths. On one path the size will be 32, the other it will be 30. If we don't duplicate this test, then the size will be 32. */ if (__builtin_object_size (r, 1) != 2 * 16 && __builtin_object_size (r, 1) != 30) abort (); +#endif if (x < 20) r = malloc (30); else r = calloc (2, 14); +#ifdef DYNAMIC_OBJECT_SIZE + if (__builtin_object_size (r, 1) != (x < 20 ? 30 : 2 * 14)) + abort (); +#else if (__builtin_object_size (r, 1) != 30) abort (); +#endif if (x < 30) r = malloc (sizeof (a)); else r = &a.a[3]; +#ifdef DYNAMIC_OBJECT_SIZE + if (__builtin_object_size (r, 1) != (x < 30 ? sizeof (a) : sizeof (a) - 3)) + abort (); +#else if (__builtin_object_size (r, 1) != sizeof (a)) abort (); +#endif r = memcpy (r, "a", 2); +#ifdef DYNAMIC_OBJECT_SIZE + if (__builtin_object_size (r, 1) != (x < 30 ? sizeof (a) : sizeof (a) - 3)) + abort (); +#else if (__builtin_object_size (r, 1) != sizeof (a)) abort (); +#endif r = memcpy (r + 2, "b", 2) + 2; +#ifdef DYNAMIC_OBJECT_SIZE + if (__builtin_object_size (r, 0) + != (x < 30 ? sizeof (a) - 4 : sizeof (a) - 7)) + abort (); +#else if (__builtin_object_size (r, 1) != sizeof (a) - 4) abort (); +#endif r = &a.a[4]; r = memset (r, 'a', 2); if (__builtin_object_size (r, 1) != sizeof (a.a) - 4) @@ -142,27 +168,28 @@ test1 (void *q, int x) abort (); if (__builtin_object_size (var + 10, 1) != x) abort (); + if (__builtin_object_size (&var[5], 1) != x + 5) + abort (); + if (__builtin_object_size (vara, 1) != (x + 10) * sizeof (struct A)) + abort (); + if (__builtin_object_size (vara + 10, 1) != x * sizeof (struct A)) + abort (); + if (__builtin_object_size (&vara[5], 1) != (x + 5) * sizeof (struct A)) + abort (); #else if (__builtin_object_size (var, 1) != (size_t) -1) abort (); if (__builtin_object_size (var + 10, 1) != (size_t) -1) abort (); -#endif if (__builtin_object_size (&var[5], 1) != (size_t) -1) abort (); -#ifdef DYNAMIC_OBJECT_SIZE - if (__builtin_object_size (vara, 1) != (x + 10) * sizeof (struct A)) - abort (); - if (__builtin_object_size (vara + 10, 1) != x * sizeof (struct A)) - abort (); -#else if (__builtin_object_size (vara, 1) != (size_t) -1) abort (); if (__builtin_object_size (vara + 10, 1) != (size_t) -1) abort (); -#endif if (__builtin_object_size (&vara[5], 1) != (size_t) -1) abort (); +#endif if (__builtin_object_size (&vara[0].a, 1) != sizeof (vara[0].a)) abort (); if (__builtin_object_size (&vara[10].a[0], 1) != sizeof (vara[0].a)) diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-3.c b/gcc/testsuite/gcc.dg/builtin-object-size-3.c index 5b323ca3527..ce4418e785b 100644 --- a/gcc/testsuite/gcc.dg/builtin-object-size-3.c +++ b/gcc/testsuite/gcc.dg/builtin-object-size-3.c @@ -42,9 +42,17 @@ test1 (void *q, int x) abort (); if (__builtin_object_size (q, 2) != 0) abort (); +#ifdef DYNAMIC_OBJECT_SIZE + if (__builtin_object_size (r, 2) + != (x < 0 + ? sizeof (a) - __builtin_offsetof (struct A, a) - 9 + : sizeof (a) - __builtin_offsetof (struct A, c) - 1)) + abort (); +#else if (__builtin_object_size (r, 2) != sizeof (a) - __builtin_offsetof (struct A, c) - 1) abort (); +#endif if (x < 6) r = &w[2].a[1]; else @@ -58,15 +66,28 @@ test1 (void *q, int x) if (__builtin_object_size (&y.b, 2) != sizeof (a) - __builtin_offsetof (struct A, b)) abort (); +#ifdef DYNAMIC_OBJECT_SIZE + if (__builtin_object_size (r, 2) + != (x < 6 + ? 2 * sizeof (w[0]) - __builtin_offsetof (struct A, a) - 1 + : sizeof (a) - __builtin_offsetof (struct A, a) - 6)) + abort (); +#else if (__builtin_object_size (r, 2) != sizeof (a) - __builtin_offsetof (struct A, a) - 6) abort (); +#endif if (x < 20) r = malloc (30); else r = calloc (2, 16); +#ifdef DYNAMIC_OBJECT_SIZE + if (__builtin_object_size (r, 2) != (x < 20 ? 30 : 2 * 16)) + abort (); +#else if (__builtin_object_size (r, 2) != 30) abort (); +#endif if (x < 20) r = malloc (30); else @@ -145,14 +166,16 @@ test1 (void *q, int x) abort (); if (__builtin_object_size (var + 10, 2) != x) abort (); + if (__builtin_object_size (&var[5], 2) != x + 5) + abort (); #else if (__builtin_object_size (var, 2) != 0) abort (); if (__builtin_object_size (var + 10, 2) != 0) abort (); -#endif if (__builtin_object_size (&var[5], 2) != 0) abort (); +#endif if (__builtin_object_size (zerol, 2) != 0) abort (); if (__builtin_object_size (&zerol, 2) != 0) diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-4.c b/gcc/testsuite/gcc.dg/builtin-object-size-4.c index 2d222301eff..81e0255dcc4 100644 --- a/gcc/testsuite/gcc.dg/builtin-object-size-4.c +++ b/gcc/testsuite/gcc.dg/builtin-object-size-4.c @@ -155,27 +155,28 @@ test1 (void *q, int x) abort (); if (__builtin_object_size (var + 10, 3) != x) abort (); + if (__builtin_object_size (&var[5], 3) != x + 5) + abort (); + if (__builtin_object_size (vara, 3) != (x + 10) * sizeof (struct A)) + abort (); + if (__builtin_object_size (vara + 10, 3) != x * sizeof (struct A)) + abort (); + if (__builtin_object_size (&vara[5], 3) != (x + 5) * sizeof (struct A)) + abort (); #else if (__builtin_object_size (var, 3) != 0) abort (); if (__builtin_object_size (var + 10, 3) != 0) abort (); -#endif if (__builtin_object_size (&var[5], 3) != 0) abort (); -#ifdef DYNAMIC_OBJECT_SIZE - if (__builtin_object_size (vara, 3) != (x + 10) * sizeof (struct A)) - abort (); - if (__builtin_object_size (vara + 10, 3) != x * sizeof (struct A)) - abort (); -#else if (__builtin_object_size (vara, 3) != 0) abort (); if (__builtin_object_size (vara + 10, 3) != 0) abort (); -#endif if (__builtin_object_size (&vara[5], 3) != 0) abort (); +#endif if (__builtin_object_size (&vara[0].a, 3) != sizeof (vara[0].a)) abort (); if (__builtin_object_size (&vara[10].a[0], 3) != sizeof (vara[0].a)) diff --git a/gcc/tree-object-size.c b/gcc/tree-object-size.c index d5b0c8226f0..865fc3feea5 100644 --- a/gcc/tree-object-size.c +++ b/gcc/tree-object-size.c @@ -123,6 +123,16 @@ size_unknown_p (tree val, int object_size_type) && tree_to_uhwi (val) == unknown (object_size_type)); } +/* Return true if VAL is represents a known size for OBJECT_SIZE_TYPE. */ + +static inline bool +size_known_p (tree val, int object_size_type) +{ + return (!size_unknown_p (val, object_size_type) + && ((object_size_type & OST_DYNAMIC) + || TREE_CODE (val) == INTEGER_CST)); +} + /* Return a tree with initial value for OBJECT_SIZE_TYPE. */ static inline tree @@ -391,16 +401,15 @@ addr_object_size (struct object_size_info *osi, const_tree ptr, if (!size_unknown_p (sz, object_size_type)) { tree offset = TREE_OPERAND (pt_var, 1); - if (TREE_CODE (offset) != INTEGER_CST - || TREE_CODE (sz) != INTEGER_CST) + if (TREE_CODE (offset) != INTEGER_CST) sz = size_unknown (object_size_type); else sz = size_for_offset (sz, offset); } if (!size_unknown_p (sz, object_size_type) - && TREE_CODE (sz) == INTEGER_CST - && compare_tree_int (sz, offset_limit) < 0) + && (TREE_CODE (sz) != INTEGER_CST + || compare_tree_int (sz, offset_limit) < 0)) pt_var_size = sz; } else if (DECL_P (pt_var)) @@ -416,8 +425,9 @@ addr_object_size (struct object_size_info *osi, const_tree ptr, if (pt_var_size) { - /* Validate the size determined above. */ - if (compare_tree_int (pt_var_size, offset_limit) >= 0) + /* Validate the size determined above if it is a constant. */ + if (TREE_CODE (pt_var_size) == INTEGER_CST + && compare_tree_int (pt_var_size, offset_limit) >= 0) return false; } @@ -441,7 +451,7 @@ addr_object_size (struct object_size_info *osi, const_tree ptr, var = TREE_OPERAND (var, 0); if (! TYPE_SIZE_UNIT (TREE_TYPE (var)) || ! tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (var))) - || (pt_var_size + || (pt_var_size && TREE_CODE (pt_var_size) == INTEGER_CST && tree_int_cst_lt (pt_var_size, TYPE_SIZE_UNIT (TREE_TYPE (var))))) var = pt_var; @@ -455,17 +465,11 @@ addr_object_size (struct object_size_info *osi, const_tree ptr, switch (TREE_CODE (v)) { case ARRAY_REF: - if (TYPE_SIZE_UNIT (TREE_TYPE (TREE_OPERAND (v, 0))) - && TREE_CODE (TREE_OPERAND (v, 1)) == INTEGER_CST) + if (TYPE_SIZE_UNIT (TREE_TYPE (TREE_OPERAND (v, 0)))) { tree domain = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (v, 0))); - if (domain - && TYPE_MAX_VALUE (domain) - && TREE_CODE (TYPE_MAX_VALUE (domain)) - == INTEGER_CST - && tree_int_cst_lt (TREE_OPERAND (v, 1), - TYPE_MAX_VALUE (domain))) + if (domain && TYPE_MAX_VALUE (domain)) { v = NULL_TREE; break; @@ -532,20 +536,20 @@ addr_object_size (struct object_size_info *osi, const_tree ptr, var = pt_var; if (var != pt_var) - var_size = TYPE_SIZE_UNIT (TREE_TYPE (var)); + { + var_size = TYPE_SIZE_UNIT (TREE_TYPE (var)); + if (!TREE_CONSTANT (var_size)) + var_size = get_or_create_ssa_default_def (cfun, var_size); + if (!var_size) + return false; + } else if (!pt_var_size) return false; else var_size = pt_var_size; bytes = compute_object_offset (TREE_OPERAND (ptr, 0), var); if (bytes != error_mark_node) - { - if (TREE_CODE (bytes) == INTEGER_CST - && tree_int_cst_lt (var_size, bytes)) - bytes = size_zero_node; - else - bytes = size_binop (MINUS_EXPR, var_size, bytes); - } + bytes = size_for_offset (var_size, bytes); if (var != pt_var && pt_var_size && TREE_CODE (pt_var) == MEM_REF @@ -554,11 +558,7 @@ addr_object_size (struct object_size_info *osi, const_tree ptr, tree bytes2 = compute_object_offset (TREE_OPERAND (ptr, 0), pt_var); if (bytes2 != error_mark_node) { - if (TREE_CODE (bytes2) == INTEGER_CST - && tree_int_cst_lt (pt_var_size, bytes2)) - bytes2 = size_zero_node; - else - bytes2 = size_binop (MINUS_EXPR, pt_var_size, bytes2); + bytes2 = size_for_offset (pt_var_size, bytes2); bytes = size_binop (MIN_EXPR, bytes, bytes2); } } @@ -568,8 +568,13 @@ addr_object_size (struct object_size_info *osi, const_tree ptr, else bytes = pt_var_size; - *psize = bytes; - return true; + if (size_known_p (bytes, object_size_type)) + { + *psize = bytes; + return true; + } + + return false; } @@ -739,19 +744,27 @@ estimate_size (object_size_info *osi, tree size, bitmap *visitlog = NULL) case PLUS_EXPR: { tree ret = estimate_size (osi, TREE_OPERAND (size, 0), visitlog); + tree off = TREE_OPERAND (size, 1); if (size_unknown_p (ret, object_size_type)) return size_unknown (object_size_type); - tree off = TREE_OPERAND (size, 1); - gcc_checking_assert (TREE_CODE (off) == INTEGER_CST); - - if (code == PLUS_EXPR) - off = fold_build1 (NEGATE_EXPR, sizetype, off); - - if (tree_fits_uhwi_p (ret) && tree_int_cst_le (ret, off)) - return size_int (0); - return size_binop (MINUS_EXPR, ret, off); + /* We don't need this for dynamic object sizes because we don't make + reducing estimates like in case of static sizes. Instead, we + return an expression that gives the precise size after a specific + number of iterations, reducing to zero at runtime if the pointer + being evaluated overflows. */ + if (!(object_size_type & OST_DYNAMIC)) + { + gcc_checking_assert (TREE_CODE (off) == INTEGER_CST); + if (code == PLUS_EXPR) + { + off = fold_build1 (NEGATE_EXPR, sizetype, off); + ret = size_binop (MAX_EXPR, ret, off); + code = MINUS_EXPR; + } + } + return size_binop (code, ret, off); } case INTEGER_CST: default: @@ -1163,7 +1176,7 @@ call_object_size (struct object_size_info *osi, gcall *call) tree bytes = alloc_object_size (call, object_size_type); - if ((object_size_type & OST_DYNAMIC) || TREE_CODE (bytes) == INTEGER_CST) + if (size_known_p (bytes, object_size_type)) return bytes; return size_unknown (object_size_type);

[09/10] tree-object-size: Dynamic sizes for ADDR_EXPR

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