From: Siddhesh Poyarekar <siddhesh@gotplt.org>
To: gcc-patches@gcc.gnu.org
Cc: jakub@redhat.com
Subject: Re: [PATCH] tree-object-size: Support strndup and strdup
Date: Thu, 15 Sep 2022 10:00:11 -0400 [thread overview]
Message-ID: <722b2d59-4482-a29f-b2e9-99d9242fda31@gotplt.org> (raw)
In-Reply-To: <3544076e-05f4-a69a-95bc-cc48190db699@gotplt.org>
Ping!
On 2022-09-07 15:21, Siddhesh Poyarekar wrote:
> Ping!
>
> On 2022-08-29 10:16, Siddhesh Poyarekar wrote:
>> Ping!
>>
>> On 2022-08-15 15:23, Siddhesh Poyarekar wrote:
>>> Use string length of input to strdup to determine the usable size of the
>>> resulting object. Avoid doing the same for strndup since there's a
>>> chance that the input may be too large, resulting in an unnecessary
>>> overhead or worse, the input may not be NULL terminated, resulting in a
>>> crash where there would otherwise have been none.
>>>
>>> gcc/ChangeLog:
>>>
>>> * tree-object-size.cc (get_whole_object): New function.
>>> (addr_object_size): Use it.
>>> (strdup_object_size): New function.
>>> (call_object_size): Use it.
>>> (pass_data_object_sizes, pass_data_early_object_sizes): Set
>>> todo_flags_finish to TODO_update_ssa_no_phi.
>>>
>>> gcc/testsuite/ChangeLog:
>>>
>>> * gcc.dg/builtin-dynamic-object-size-0.c (test_strdup,
>>> test_strndup, test_strdup_min, test_strndup_min): New tests.
>>> (main): Call them.
>>> * gcc.dg/builtin-dynamic-object-size-1.c: Silence overread
>>> warnings.
>>> * gcc.dg/builtin-dynamic-object-size-2.c: Likewise.
>>> * gcc.dg/builtin-dynamic-object-size-3.c: Likewise.
>>> * gcc.dg/builtin-dynamic-object-size-4.c: Likewise.
>>> * gcc.dg/builtin-object-size-1.c: Silence overread warnings.
>>> Declare free, strdup and strndup.
>>> (test11): New test.
>>> (main): Call it.
>>> * gcc.dg/builtin-object-size-2.c: Silence overread warnings.
>>> Declare free, strdup and strndup.
>>> (test9): New test.
>>> (main): Call it.
>>> * gcc.dg/builtin-object-size-3.c: Silence overread warnings.
>>> Declare free, strdup and strndup.
>>> (test11): New test.
>>> (main): Call it.
>>> * gcc.dg/builtin-object-size-4.c: Silence overread warnings.
>>> Declare free, strdup and strndup.
>>> (test9): New test.
>>> (main): Call it.
>>> ---
>>> .../gcc.dg/builtin-dynamic-object-size-0.c | 43 +++++++++++
>>> .../gcc.dg/builtin-dynamic-object-size-1.c | 2 +-
>>> .../gcc.dg/builtin-dynamic-object-size-2.c | 2 +-
>>> .../gcc.dg/builtin-dynamic-object-size-3.c | 2 +-
>>> .../gcc.dg/builtin-dynamic-object-size-4.c | 2 +-
>>> gcc/testsuite/gcc.dg/builtin-object-size-1.c | 64 +++++++++++++++-
>>> gcc/testsuite/gcc.dg/builtin-object-size-2.c | 63 ++++++++++++++-
>>> gcc/testsuite/gcc.dg/builtin-object-size-3.c | 63 ++++++++++++++-
>>> gcc/testsuite/gcc.dg/builtin-object-size-4.c | 63 ++++++++++++++-
>>> gcc/tree-object-size.cc | 76 +++++++++++++++++--
>>> 10 files changed, 366 insertions(+), 14 deletions(-)
>>>
>>> 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 01a280b2d7b..7f023708b15 100644
>>> --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-0.c
>>> +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-0.c
>>> @@ -479,6 +479,40 @@ test_loop (int *obj, size_t sz, size_t start,
>>> size_t end, int incr)
>>> return __builtin_dynamic_object_size (ptr, 0);
>>> }
>>> +/* strdup/strndup. */
>>> +
>>> +size_t
>>> +__attribute__ ((noinline))
>>> +test_strdup (const char *in)
>>> +{
>>> + char *res = __builtin_strdup (in);
>>> + return __builtin_dynamic_object_size (res, 0);
>>> +}
>>> +
>>> +size_t
>>> +__attribute__ ((noinline))
>>> +test_strndup (const char *in, size_t bound)
>>> +{
>>> + char *res = __builtin_strndup (in, bound);
>>> + return __builtin_dynamic_object_size (res, 0);
>>> +}
>>> +
>>> +size_t
>>> +__attribute__ ((noinline))
>>> +test_strdup_min (const char *in)
>>> +{
>>> + char *res = __builtin_strdup (in);
>>> + return __builtin_dynamic_object_size (res, 2);
>>> +}
>>> +
>>> +size_t
>>> +__attribute__ ((noinline))
>>> +test_strndup_min (const char *in, size_t bound)
>>> +{
>>> + char *res = __builtin_strndup (in, bound);
>>> + return __builtin_dynamic_object_size (res, 2);
>>> +}
>>> +
>>> /* Other tests. */
>>> struct TV4
>>> @@ -651,6 +685,15 @@ main (int argc, char **argv)
>>> int *t = test_pr105736 (&val3);
>>> if (__builtin_dynamic_object_size (t, 0) != -1)
>>> FAIL ();
>>> + const char *str = "hello world";
>>> + if (test_strdup (str) != __builtin_strlen (str) + 1)
>>> + FAIL ();
>>> + if (test_strndup (str, 4) != 5)
>>> + FAIL ();
>>> + if (test_strdup_min (str) != __builtin_strlen (str) + 1)
>>> + FAIL ();
>>> + if (test_strndup_min (str, 4) != 0)
>>> + FAIL ();
>>> if (nfails > 0)
>>> __builtin_abort ();
>>> diff --git a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-1.c
>>> b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-1.c
>>> index 7cc8b1c9488..8f17c8edcaf 100644
>>> --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-1.c
>>> +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-1.c
>>> @@ -1,5 +1,5 @@
>>> /* { dg-do run } */
>>> -/* { dg-options "-O2" } */
>>> +/* { dg-options "-O2 -Wno-stringop-overread" } */
>>> /* { dg-require-effective-target alloca } */
>>> #define __builtin_object_size __builtin_dynamic_object_size
>>> diff --git a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-2.c
>>> b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-2.c
>>> index 267dbf48ca7..3677782ff1c 100644
>>> --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-2.c
>>> +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-2.c
>>> @@ -1,5 +1,5 @@
>>> /* { dg-do run } */
>>> -/* { dg-options "-O2" } */
>>> +/* { dg-options "-O2 -Wno-stringop-overread" } */
>>> /* { dg-require-effective-target alloca } */
>>> #define __builtin_object_size __builtin_dynamic_object_size
>>> diff --git a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-3.c
>>> b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-3.c
>>> index fb9dc56da7e..5b6987b7773 100644
>>> --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-3.c
>>> +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-3.c
>>> @@ -1,5 +1,5 @@
>>> /* { dg-do run } */
>>> -/* { dg-options "-O2" } */
>>> +/* { dg-options "-O2 -Wno-stringop-overread" } */
>>> /* { dg-require-effective-target alloca } */
>>> #define __builtin_object_size __builtin_dynamic_object_size
>>> diff --git a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-4.c
>>> b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-4.c
>>> index 870548b4206..9d796224e96 100644
>>> --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-4.c
>>> +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-4.c
>>> @@ -1,5 +1,5 @@
>>> /* { dg-do run } */
>>> -/* { dg-options "-O2" } */
>>> +/* { dg-options "-O2 -Wno-stringop-overread" } */
>>> /* { dg-require-effective-target alloca } */
>>> #define __builtin_object_size __builtin_dynamic_object_size
>>> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-1.c
>>> b/gcc/testsuite/gcc.dg/builtin-object-size-1.c
>>> index b772e2da9b9..4fbd372d97a 100644
>>> --- a/gcc/testsuite/gcc.dg/builtin-object-size-1.c
>>> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-1.c
>>> @@ -1,5 +1,5 @@
>>> /* { dg-do run } */
>>> -/* { dg-options "-O2" } */
>>> +/* { dg-options "-O2 -Wno-stringop-overread" } */
>>> /* { dg-require-effective-target alloca } */
>>> typedef __SIZE_TYPE__ size_t;
>>> @@ -7,10 +7,13 @@ extern void abort (void);
>>> extern void exit (int);
>>> extern void *malloc (size_t);
>>> extern void *calloc (size_t, size_t);
>>> +extern void free (void *);
>>> extern void *alloca (size_t);
>>> extern void *memcpy (void *, const void *, size_t);
>>> extern void *memset (void *, int, size_t);
>>> extern char *strcpy (char *, const char *);
>>> +extern char *strdup (const char *);
>>> +extern char *strndup (const char *, size_t);
>>> struct A
>>> {
>>> @@ -629,6 +632,64 @@ test10 (void)
>>> }
>>> }
>>> +/* Tests for strdup/strndup. */
>>> +size_t
>>> +__attribute__ ((noinline))
>>> +test11 (void)
>>> +{
>>> + int i = 0;
>>> + const char *ptr = "abcdefghijklmnopqrstuvwxyz";
>>> + char *res = strndup (ptr, 21);
>>> + if (__builtin_object_size (res, 0) != 22)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + res = strndup (ptr, 32);
>>> + if (__builtin_object_size (res, 0) != 27)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + res = strdup (ptr);
>>> + if (__builtin_object_size (res, 0) != 27)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + char *ptr2 = malloc (64);
>>> + strcpy (ptr2, ptr);
>>> +
>>> + res = strndup (ptr2, 21);
>>> + if (__builtin_object_size (res, 0) != 22)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + res = strndup (ptr2, 32);
>>> + if (__builtin_object_size (res, 0) != 33)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + res = strndup (ptr2, 128);
>>> + if (__builtin_object_size (res, 0) != 64)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + res = strdup (ptr2);
>>> +#ifdef __builtin_object_size
>>> + if (__builtin_object_size (res, 0) != 27)
>>> +#else
>>> + if (__builtin_object_size (res, 0) != 64)
>>> +#endif
>>> + abort ();
>>> +
>>> + free (res);
>>> + free (ptr2);
>>> +}
>>> +
>>> int
>>> main (void)
>>> {
>>> @@ -644,5 +705,6 @@ main (void)
>>> test8 ();
>>> test9 (1);
>>> test10 ();
>>> + test11 ();
>>> exit (0);
>>> }
>>> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-2.c
>>> b/gcc/testsuite/gcc.dg/builtin-object-size-2.c
>>> index 2729538da17..beb271c5afc 100644
>>> --- a/gcc/testsuite/gcc.dg/builtin-object-size-2.c
>>> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-2.c
>>> @@ -1,5 +1,5 @@
>>> /* { dg-do run } */
>>> -/* { dg-options "-O2" } */
>>> +/* { dg-options "-O2 -Wno-stringop-overread" } */
>>> /* { dg-require-effective-target alloca } */
>>> typedef __SIZE_TYPE__ size_t;
>>> @@ -7,10 +7,13 @@ extern void abort (void);
>>> extern void exit (int);
>>> extern void *malloc (size_t);
>>> extern void *calloc (size_t, size_t);
>>> +extern void free (void *);
>>> extern void *alloca (size_t);
>>> extern void *memcpy (void *, const void *, size_t);
>>> extern void *memset (void *, int, size_t);
>>> extern char *strcpy (char *, const char *);
>>> +extern char *strdup (const char *);
>>> +extern char *strndup (const char *, size_t);
>>> struct A
>>> {
>>> @@ -544,6 +547,63 @@ test8 (unsigned cond)
>>> #endif
>>> }
>>> +/* Tests for strdup/strndup. */
>>> +size_t
>>> +__attribute__ ((noinline))
>>> +test9 (void)
>>> +{
>>> + const char *ptr = "abcdefghijklmnopqrstuvwxyz";
>>> + char *res = strndup (ptr, 21);
>>> + if (__builtin_object_size (res, 1) != 22)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + res = strndup (ptr, 32);
>>> + if (__builtin_object_size (res, 1) != 27)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + res = strdup (ptr);
>>> + if (__builtin_object_size (res, 1) != 27)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + char *ptr2 = malloc (64);
>>> + strcpy (ptr2, ptr);
>>> +
>>> + res = strndup (ptr2, 21);
>>> + if (__builtin_object_size (res, 1) != 22)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + res = strndup (ptr2, 32);
>>> + if (__builtin_object_size (res, 1) != 33)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + res = strndup (ptr2, 128);
>>> + if (__builtin_object_size (res, 1) != 64)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + res = strdup (ptr2);
>>> +#ifdef __builtin_object_size
>>> + if (__builtin_object_size (res, 1) != 27)
>>> +#else
>>> + if (__builtin_object_size (res, 1) != 64)
>>> +#endif
>>> + abort ();
>>> +
>>> + free (res);
>>> + free (ptr2);
>>> +}
>>> +
>>> int
>>> main (void)
>>> {
>>> @@ -557,5 +617,6 @@ main (void)
>>> test6 ();
>>> test7 ();
>>> test8 (1);
>>> + test9 ();
>>> exit (0);
>>> }
>>> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-3.c
>>> b/gcc/testsuite/gcc.dg/builtin-object-size-3.c
>>> index 44a99189776..5c878a14647 100644
>>> --- a/gcc/testsuite/gcc.dg/builtin-object-size-3.c
>>> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-3.c
>>> @@ -1,5 +1,5 @@
>>> /* { dg-do run } */
>>> -/* { dg-options "-O2" } */
>>> +/* { dg-options "-O2 -Wno-stringop-overread" } */
>>> /* { dg-require-effective-target alloca } */
>>> typedef __SIZE_TYPE__ size_t;
>>> @@ -7,10 +7,13 @@ extern void abort (void);
>>> extern void exit (int);
>>> extern void *malloc (size_t);
>>> extern void *calloc (size_t, size_t);
>>> +extern void free (void *);
>>> extern void *alloca (size_t);
>>> extern void *memcpy (void *, const void *, size_t);
>>> extern void *memset (void *, int, size_t);
>>> extern char *strcpy (char *, const char *);
>>> +extern char *strdup (const char *);
>>> +extern char *strndup (const char *, size_t);
>>> struct A
>>> {
>>> @@ -636,6 +639,63 @@ test10 (void)
>>> }
>>> }
>>> +/* Tests for strdup/strndup. */
>>> +size_t
>>> +__attribute__ ((noinline))
>>> +test11 (void)
>>> +{
>>> + const char *ptr = "abcdefghijklmnopqrstuvwxyz";
>>> + char *res = strndup (ptr, 21);
>>> + if (__builtin_object_size (res, 2) != 22)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + res = strndup (ptr, 32);
>>> + if (__builtin_object_size (res, 2) != 27)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + res = strdup (ptr);
>>> + if (__builtin_object_size (res, 2) != 27)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + char *ptr2 = malloc (64);
>>> + strcpy (ptr2, ptr);
>>> +
>>> + res = strndup (ptr2, 21);
>>> + if (__builtin_object_size (res, 2) != 0)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + res = strndup (ptr2, 32);
>>> + if (__builtin_object_size (res, 2) != 0)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + res = strndup (ptr2, 128);
>>> + if (__builtin_object_size (res, 2) != 0)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + res = strdup (ptr2);
>>> +#ifdef __builtin_object_size
>>> + if (__builtin_object_size (res, 2) != 27)
>>> +#else
>>> + if (__builtin_object_size (res, 2) != 0)
>>> +#endif
>>> + abort ();
>>> +
>>> + free (res);
>>> + free (ptr2);
>>> +}
>>> +
>>> int
>>> main (void)
>>> {
>>> @@ -651,5 +711,6 @@ main (void)
>>> test8 ();
>>> test9 (1);
>>> test10 ();
>>> + test11 ();
>>> exit (0);
>>> }
>>> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-4.c
>>> b/gcc/testsuite/gcc.dg/builtin-object-size-4.c
>>> index b9fddfed036..0b1cb1e528a 100644
>>> --- a/gcc/testsuite/gcc.dg/builtin-object-size-4.c
>>> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-4.c
>>> @@ -1,5 +1,5 @@
>>> /* { dg-do run } */
>>> -/* { dg-options "-O2" } */
>>> +/* { dg-options "-O2 -Wno-stringop-overread" } */
>>> /* { dg-require-effective-target alloca } */
>>> typedef __SIZE_TYPE__ size_t;
>>> @@ -7,10 +7,13 @@ extern void abort (void);
>>> extern void exit (int);
>>> extern void *malloc (size_t);
>>> extern void *calloc (size_t, size_t);
>>> +extern void free (void *);
>>> extern void *alloca (size_t);
>>> extern void *memcpy (void *, const void *, size_t);
>>> extern void *memset (void *, int, size_t);
>>> extern char *strcpy (char *, const char *);
>>> +extern char *strdup (const char *);
>>> +extern char *strndup (const char *, size_t);
>>> struct A
>>> {
>>> @@ -517,6 +520,63 @@ test8 (unsigned cond)
>>> #endif
>>> }
>>> +/* Tests for strdup/strndup. */
>>> +size_t
>>> +__attribute__ ((noinline))
>>> +test9 (void)
>>> +{
>>> + const char *ptr = "abcdefghijklmnopqrstuvwxyz";
>>> + char *res = strndup (ptr, 21);
>>> + if (__builtin_object_size (res, 3) != 22)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + res = strndup (ptr, 32);
>>> + if (__builtin_object_size (res, 3) != 27)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + res = strdup (ptr);
>>> + if (__builtin_object_size (res, 3) != 27)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + char *ptr2 = malloc (64);
>>> + strcpy (ptr2, ptr);
>>> +
>>> + res = strndup (ptr2, 21);
>>> + if (__builtin_object_size (res, 3) != 0)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + res = strndup (ptr2, 32);
>>> + if (__builtin_object_size (res, 3) != 0)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + res = strndup (ptr2, 128);
>>> + if (__builtin_object_size (res, 3) != 0)
>>> + abort ();
>>> +
>>> + free (res);
>>> +
>>> + res = strdup (ptr2);
>>> +#ifdef __builtin_object_size
>>> + if (__builtin_object_size (res, 3) != 27)
>>> +#else
>>> + if (__builtin_object_size (res, 3) != 0)
>>> +#endif
>>> + abort ();
>>> +
>>> + free (res);
>>> + free (ptr2);
>>> +}
>>> +
>>> int
>>> main (void)
>>> {
>>> @@ -530,5 +590,6 @@ main (void)
>>> test6 ();
>>> test7 ();
>>> test8 (1);
>>> + test9 ();
>>> exit (0);
>>> }
>>> diff --git a/gcc/tree-object-size.cc b/gcc/tree-object-size.cc
>>> index 4eb454a4a33..c075b71db56 100644
>>> --- a/gcc/tree-object-size.cc
>>> +++ b/gcc/tree-object-size.cc
>>> @@ -495,6 +495,18 @@ decl_init_size (tree decl, bool min)
>>> return size;
>>> }
>>> +/* Get the outermost object that PTR may point into. */
>>> +
>>> +static tree
>>> +get_whole_object (const_tree ptr)
>>> +{
>>> + tree pt_var = TREE_OPERAND (ptr, 0);
>>> + while (handled_component_p (pt_var))
>>> + pt_var = TREE_OPERAND (pt_var, 0);
>>> +
>>> + return pt_var;
>>> +}
>>> +
>>> /* Compute __builtin_object_size for PTR, which is a ADDR_EXPR.
>>> OBJECT_SIZE_TYPE is the second argument from __builtin_object_size.
>>> If unknown, return size_unknown (object_size_type). */
>>> @@ -514,9 +526,7 @@ addr_object_size (struct object_size_info *osi,
>>> const_tree ptr,
>>> if (pwholesize)
>>> *pwholesize = size_unknown (object_size_type);
>>> - pt_var = TREE_OPERAND (ptr, 0);
>>> - while (handled_component_p (pt_var))
>>> - pt_var = TREE_OPERAND (pt_var, 0);
>>> + pt_var = get_whole_object (ptr);
>>> if (!pt_var)
>>> return false;
>>> @@ -789,6 +799,53 @@ alloc_object_size (const gcall *call, int
>>> object_size_type)
>>> return bytes ? bytes : size_unknown (object_size_type);
>>> }
>>> +/* Compute __builtin_object_size for CALL, which is a call to either
>>> + BUILT_IN_STRDUP or BUILT_IN_STRNDUP; IS_STRNDUP indicates which
>>> it is.
>>> + OBJECT_SIZE_TYPE is the second argument from __builtin_object_size.
>>> + If unknown, return size_unknown (object_size_type). */
>>> +
>>> +static tree
>>> +strdup_object_size (const gcall *call, int object_size_type, bool
>>> is_strndup)
>>> +{
>>> + tree src = gimple_call_arg (call, 0);
>>> + tree sz = size_unknown (object_size_type);
>>> + tree n = is_strndup ? gimple_call_arg (call, 1) : NULL_TREE;
>>> +
>>> + /* For strdup, simply emit strlen (SRC) + 1 and let the optimizer
>>> fold it the
>>> + way it likes. */
>>> + if (!is_strndup)
>>> + {
>>> + tree strlen_fn = builtin_decl_implicit (BUILT_IN_STRLEN);
>>> + if (strlen_fn)
>>> + sz = fold_build2 (PLUS_EXPR, sizetype, size_one_node,
>>> + build_call_expr (strlen_fn, 1, src));
>>> + }
>>> +
>>> + /* In all other cases, return the size of SRC since the object
>>> size cannot
>>> + exceed that. We cannot do this for OST_MINIMUM unless SRC
>>> points into a
>>> + string constant since otherwise the object size could go all
>>> the way down
>>> + to zero. */
>>> + if (!size_valid_p (sz, object_size_type)
>>> + || size_unknown_p (sz, object_size_type))
>>> + {
>>> + tree wholesrc = NULL_TREE;
>>> + if (TREE_CODE (src) == ADDR_EXPR)
>>> + wholesrc = get_whole_object (src);
>>> +
>>> + if (!(object_size_type & OST_MINIMUM)
>>> + || (wholesrc && TREE_CODE (wholesrc) == STRING_CST))
>>> + compute_builtin_object_size (src, object_size_type, &sz);
>>> + }
>>> +
>>> + if (!n)
>>> + return sz;
>>> +
>>> + /* Factor in the N. Note that with OST_MINIMUM, even if N is
>>> known we return
>>> + 0 since the size could be less than N. */
>>> + return fold_build2 (MIN_EXPR, sizetype,
>>> + fold_build2 (PLUS_EXPR, sizetype, size_one_node, n),
>>> + sz);
>>> +}
>>> /* If object size is propagated from one of function's arguments
>>> directly
>>> to its return value, return that argument for GIMPLE_CALL
>>> statement CALL.
>>> @@ -1235,12 +1292,19 @@ call_object_size (struct object_size_info
>>> *osi, tree ptr, gcall *call)
>>> {
>>> int object_size_type = osi->object_size_type;
>>> unsigned int varno = SSA_NAME_VERSION (ptr);
>>> + tree bytes = NULL_TREE;
>>> gcc_assert (is_gimple_call (call));
>>> gcc_assert (!object_sizes_unknown_p (object_size_type, varno));
>>> gcc_assert (osi->pass == 0);
>>> - tree bytes = alloc_object_size (call, object_size_type);
>>> +
>>> + bool is_strdup = gimple_call_builtin_p (call, BUILT_IN_STRDUP);
>>> + bool is_strndup = gimple_call_builtin_p (call, BUILT_IN_STRNDUP);
>>> + if (is_strdup || is_strndup)
>>> + bytes = strdup_object_size (call, object_size_type, is_strndup);
>>> + else
>>> + bytes = alloc_object_size (call, object_size_type);
>>> if (!size_valid_p (bytes, object_size_type))
>>> bytes = size_unknown (object_size_type);
>>> @@ -2113,7 +2177,7 @@ const pass_data pass_data_object_sizes =
>>> PROP_objsz, /* properties_provided */
>>> 0, /* properties_destroyed */
>>> 0, /* todo_flags_start */
>>> - 0, /* todo_flags_finish */
>>> + TODO_update_ssa_no_phi, /* todo_flags_finish */
>>> };
>>> class pass_object_sizes : public gimple_opt_pass
>>> @@ -2153,7 +2217,7 @@ const pass_data pass_data_early_object_sizes =
>>> 0, /* properties_provided */
>>> 0, /* properties_destroyed */
>>> 0, /* todo_flags_start */
>>> - 0, /* todo_flags_finish */
>>> + TODO_update_ssa_no_phi, /* todo_flags_finish */
>>> };
>>> class pass_early_object_sizes : public gimple_opt_pass
>>
>
next prev parent reply other threads:[~2022-09-15 14:00 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-15 19:23 Siddhesh Poyarekar
2022-08-29 14:16 ` Siddhesh Poyarekar
2022-09-07 19:21 ` Siddhesh Poyarekar
2022-09-15 14:00 ` Siddhesh Poyarekar [this message]
2022-09-22 13:02 ` Jakub Jelinek
2022-09-22 15:26 ` Siddhesh Poyarekar
2022-09-23 13:02 ` Jakub Jelinek
2022-11-02 22:30 ` Siddhesh Poyarekar
2022-11-04 12:48 ` [PATCH v2] " Siddhesh Poyarekar
2022-11-04 13:43 ` Prathamesh Kulkarni
2022-11-04 13:47 ` Siddhesh Poyarekar
2022-11-17 19:47 ` Siddhesh Poyarekar
2022-11-20 15:42 ` Jeff Law
2022-11-21 14:27 ` Siddhesh Poyarekar
2022-11-22 20:43 ` Jeff Law
2022-11-22 23:13 ` Siddhesh Poyarekar
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