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| author | Joseph Myers <joseph@codesourcery.com> | 2020-10-30 22:25:42 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2020-10-30 22:25:42 +0000 |
| commit | 548f467fa14ffe7d955beeb31b30e2aeae4467e0 (patch) | |
| tree | 110b58e4d121c3650cb103a883f02091d06c5e84 /misc | |
| parent | 882774658cb8daee4c16677a3fd674f6052cc157 (diff) | |
| download | glibc-548f467fa14ffe7d955beeb31b30e2aeae4467e0.zip glibc-548f467fa14ffe7d955beeb31b30e2aeae4467e0.tar.gz glibc-548f467fa14ffe7d955beeb31b30e2aeae4467e0.tar.bz2 | |
Avoid -Wstringop-overflow warning in pthread_cleanup_push macros
GCC 11 introduces a -Wstringop-overflow warning for calls to functions
with an array argument passed as a pointer to memory not large enough
for that array. This includes the __sigsetjmp calls from
pthread_cleanup_push macros, because those use a structure in
__pthread_unwind_buf_t, which has a common initial subsequence with
jmp_buf but does not include the saved signal mask; this is OK in this
case because the second argument to __sigsetjmp is 0 so the signal
mask is not accessed.
To avoid this warning, use a function alias __sigsetjmp_cancel with
first argument an array of exactly the type used in the calls to the
function, if using GCC 11 or later. With older compilers, continue to
use __sigsetjmp with a cast, to avoid any issues with compilers
predating the returns_twice attribute not applying the same special
handling to __sigsetjmp_cancel as to __sigsetjmp.
Tested with build-many-glibcs.py for arm-linux-gnueabi that this fixes
the testsuite build failures.
Diffstat (limited to 'misc')
| -rw-r--r-- | misc/sys/cdefs.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/misc/sys/cdefs.h b/misc/sys/cdefs.h index 6b9763a..86906c2 100644 --- a/misc/sys/cdefs.h +++ b/misc/sys/cdefs.h @@ -563,4 +563,12 @@ _Static_assert (0, "IEEE 128-bits long double requires redirection on this platf # define __attr_access(x) #endif +/* Specify that a function such as setjmp or vfork may return + twice. */ +#if __GNUC_PREREQ (4, 1) +# define __attribute_returns_twice__ __attribute__ ((__returns_twice__)) +#else +# define __attribute_returns_twice__ /* Ignore. */ +#endif + #endif /* sys/cdefs.h */ |