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| author | Siddhesh Poyarekar <siddhesh@gotplt.org> | 2021-07-28 10:33:46 +0530 |
|---|---|---|
| committer | Siddhesh Poyarekar <siddhesh@gotplt.org> | 2021-07-28 17:43:15 +0530 |
| commit | 84606efb0c6b1c1598d5ec6b05544e71596663b5 (patch) | |
| tree | cf703ac4b2312c424d3590d5cc935b5b74d0f797 | |
| parent | 54ec50bada94a8ff92edb04ee5216c27fa4bf942 (diff) | |
| download | gcc-84606efb0c6b1c1598d5ec6b05544e71596663b5.zip gcc-84606efb0c6b1c1598d5ec6b05544e71596663b5.tar.gz gcc-84606efb0c6b1c1598d5ec6b05544e71596663b5.tar.bz2 | |
analyzer: Recognize __builtin_free as a matching deallocator
Recognize __builtin_free as being equivalent to free when passed into
__attribute__((malloc ())), similar to how it is treated when it is
encountered as a call. This fixes spurious warnings in glibc where
xmalloc family of allocators as well as reallocarray, memalign,
etc. are declared to have __builtin_free as the free function.
gcc/analyzer/ChangeLog:
* sm-malloc.cc
(malloc_state_machine::get_or_create_deallocator): Recognize
__builtin_free.
gcc/testsuite/ChangeLog:
* gcc.dg/analyzer/attr-malloc-1.c (compatible_alloc,
compatible_alloc2): New extern allocator declarations.
(test_9, test_10): New tests.
| -rw-r--r-- | gcc/analyzer/sm-malloc.cc | 3 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/analyzer/attr-malloc-1.c | 19 |
2 files changed, 21 insertions, 1 deletions
diff --git a/gcc/analyzer/sm-malloc.cc b/gcc/analyzer/sm-malloc.cc index 9707a68..1d69d57 100644 --- a/gcc/analyzer/sm-malloc.cc +++ b/gcc/analyzer/sm-malloc.cc @@ -1511,7 +1511,8 @@ malloc_state_machine::get_or_create_deallocator (tree deallocator_fndecl) /* Reuse "free". */ deallocator *d; if (is_named_call_p (deallocator_fndecl, "free") - || is_std_named_call_p (deallocator_fndecl, "free")) + || is_std_named_call_p (deallocator_fndecl, "free") + || is_named_call_p (deallocator_fndecl, "__builtin_free")) d = &m_free.m_deallocator; else { diff --git a/gcc/testsuite/gcc.dg/analyzer/attr-malloc-1.c b/gcc/testsuite/gcc.dg/analyzer/attr-malloc-1.c index 3de32b1..a9a2a3d 100644 --- a/gcc/testsuite/gcc.dg/analyzer/attr-malloc-1.c +++ b/gcc/testsuite/gcc.dg/analyzer/attr-malloc-1.c @@ -11,6 +11,12 @@ extern struct foo *foo_acquire (void) extern void use_foo (const struct foo *) __attribute__((nonnull)); +extern struct foo *compatible_alloc (void) + __attribute__ ((malloc (__builtin_free))); + +extern struct foo *compatible_alloc2 (void) + __attribute__ ((malloc (free))); + void test_1 (void) { struct foo *p = foo_acquire (); @@ -73,3 +79,16 @@ int test_8 (struct foo *p) foo_release (p); return p->m_int; /* { dg-warning "use after 'foo_release' of 'p'" } */ } + +/* Recognize that __builtin_free and free are the same thing. */ +void test_9 (void) +{ + struct foo *p = compatible_alloc (); + free (p); +} + +void test_10 (void) +{ + struct foo *p = compatible_alloc2 (); + __builtin_free (p); +} |