The fix for BZ #17266 (884ddc5081)
removed changes that had gone into cdefs.h to make
__extern_always_inline usable with clang++. This patch adds back
support for clang to detect if GNU inlining semantics are available,
this time without breaking the gcc use case. The check put here is
based on the earlier patch and assertion[1] that checking if
__GNUC_STDC_INLINE__ or __GNUC_GNU_INLINE__ is defined is sufficient
to determine that clang++ suports GNU inlining semantics.
Tested with a simple program that builds with __extern_always_inline
with the patch and fails compilation without it.
#include <stdio.h>
#include <sys/cdefs.h>
extern void foo_alias (void) __asm ("foo");
__extern_always_inline void
foo (void)
{
puts ("hi oh world!");
return foo_alias ();
}
void
foo_alias (void)
{
puts ("hell oh world");
}
int
main ()
{
foo ();
}
[1] https://sourceware.org/ml/libc-alpha/2012-12/msg00306.html
[BZ #17266]
* misc/sys/cdefs.h: Define __extern_always_inline for clang
4.2 and newer.
The check for only __GNUC_STDC_INLINE__ and __GNUC_GNU_INLINE__ may
not be sufficient since those flags were added during initial support
for C99 inlining semantics. There is also a problem with always
defining __extern_inline and __extern_always_inline, since it enables
inline wrapper functions even when GNU inlining semantics are not
guaranteed. This, along with the possibility of such wrappers using
redirection (btowc for example) could result in compiler generating an
infinitely recusrive call to the function.
In fact it was such a recursion that led to this code being written
the way it was; see:
https://bugzilla.redhat.com/show_bug.cgi?id=186410
The initial change was to fix bugs 14530 and 13741, but they can be
resolved by checking if __fortify_function and/or
__extern_always_inline are defined, as it has been done in this patch.
In addition, I have audited uses of __extern_always_inline to make
sure that none of the uses result in compilation errors.
There is however a regression in this patch for llvm, since it reverts
the llvm expectation that __GNUC_STDC_INLINE__ or __GNUC_GNU_INLINE__
definition imply proper extern inline semantics.
2014-09-16 Siddhesh Poyarekar <siddhesh@redhat.com>
Jakub Jelinek <jakub@redhat.com>
[BZ #17266]
* libio/stdio.h: Check definition of __fortify_function
instead of __extern_always_inline to include bits/stdio2.h.
* math/bits/math-finite.h [__USE_XOPEN || __USE_ISOC99]: Also
check if __extern_always_inline is defined.
[__USE_MISC || __USE_XOPEN]: Likewise.
[__USE_ISOC99] Likewise.
* misc/sys/cdefs.h (__fortify_function): Define only if
__extern_always_inline is defined.
[!__cplusplus || __GNUC_PREREQ (4,3)]: Revert to defining
__extern_always_inline and __extern_inline only for g++-4.3
and newer or a compatible gcc.
c4c4124473 added the _Noreturn macro for
pre-C11 compilers, but it now throws a new Wundef warning during `make
check` for __STDC_VERSION__ which gcc does not define by default. The
following patch fixes this in line with other uses of __STDC_VERSION__
in the file.
Shifting into the sign position is currently supported as a GCC
extension, but explicitly subjected to future changes. Computation
in the unsigned type followed by a cast to the signed type is a GCC
extension that will be available forever.
[BZ 15846] As discussed in the recent thread on my $EXEC_ORIGIN patch
and in BZ 15846, getauxval() presently has no unambiguous way of
reporting an error condition. It currently returns zero on error, but
this may also be a valid result for some auxv entries. As there is no
clear invalid result for all current and future auxv entries, this patch
sets errno (following a suggestion in the BZ entry).
This version of the patch also adds documentation and tests for the
value-not-found conditions in getauxval().
Use the __gnu_inline__ attribute in _FORTIFY_SOURCE's __extern_always_inline
macro whenever the compiler supports it. Previously this macro only included
the __gnu_inline__ attribute in C++ mode for gcc >= 4.3. However,
__gnu_inline__ semantics are always desired for the __extern_always_inline
functions, and are available in g++ 4.2 (and some releases of g++ 4.1, and
also in Clang, which claims to be g++ 4.2).
This change stops g++-4.2 from emitting weak definitions for the fortify
wrapper functions if they can't be inlined, and also improves Clang
compatibility.
Since we want to use this in installed headers, move it to the installed
sys/cdefs.h. This requires a slight tweaking of the name (add trailing
underscores).
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
As reported in http://bugzilla.redhat.com/533063 , preadv/pwritev prototypes
are wrong on 32-bit arches with -D_FILE_OFFSET_BITS=64 and as I've just
found, fallocate is wrong too.
The problem is that only off_t is remapped to the 64-bit type transparently,
__off_t is not.
* misc/Versions: Export preadv, preadv64, pwritev, pwritev64 for
GLIBC_2.10.
* misc/sys/uio.h: Declare preadv, preadv64, pwritev, pwritev64.
* sysdeps/unix/sysv/linux/kernel-features.h: Add entries for preadv
and pwritev.
* misc/preadv.c: New file.
* misc/preadv64.c: New file.
* misc/pwritev.c: New file.
* misc/pwritev64.c: New file.
* sysdeps/posx/preadv.c: New file.
* sysdeps/posx/preadv64.c: New file.
* sysdeps/posx/pwritev.c: New file.
* sysdeps/posx/pwritev64.c: New file.
* sysdeps/unix/sysv/linux/preadv.c: New file.
* sysdeps/unix/sysv/linux/preadv64.c: New file.
* sysdeps/unix/sysv/linux/pwritev.c: New file.
* sysdeps/unix/sysv/linux/pwritev64.c: New file.
* sysdeps/unix/sysv/linux/wordsize-64/preadv64.c: New file.
* sysdeps/unix/sysv/linux/wordsize-64/pwritev64.c: New file.
attribute also for non-C99 inline semantics variant.
2009-03-02 Richard Guenther <rguenther@suse.de>
* misc/sys/cdefs.h (__extern_always_inline): Add __artificial__
attribute also for non-C99 inline semantics variant.
with __warning__/__error__ attributes.
(__warnattr): Define.
* stdlib/bits/stdlib.h (__realpath_chk_warn, __ptsname_r_chk_warn,
__mbstowcs_chk_warn, __wcstombs_chk_warn): New aliases with
__warnattr.
(realpath, ptsname_r, mbstowcs, wcstombs): Call __*_chk_warn instead
of __*_chk if compile time detectable overflow is found.
* libio/bits/stdio2.h (__fgets_chk_warn, __fread_chk_warn,
__fgets_unlocked_chk_warn, __fread_unlocked_chk_warn): New aliases
with __warnattr.
(fgets, fread, fgets_unlocked, fread_unlocked): Call __*_chk_warn
instead of __*_chk if compile time detectable overflow is found.
(__gets_alias): Rename to...
(__gets_warn): ... this. Add __warnattr.
(gets): Call __gets_warn instead of __gets_alias.
* socket/bits/socket2.h (__recv_chk_warn, __recvfrom_chk_warn): New
aliases with __warnattr.
(recv, recvfrom): Call __*_chk_warn instead of __*_chk if compile
time detectable overflow is found.
* posix/bits/unistd.h (__read_chk_warn, __pread_chk_warn,
__pread64_chk_warn, __readlink_chk_warn, __readlinkat_chk_warn,
__getcwd_chk_warn, __confstr_chk_warn, __getgroups_chk_warn,
__ttyname_r_chk_warn, __getlogin_r_chk_warn, __gethostname_chk_warn,
__getdomainname_chk_warn): New aliases with __warnattr.
(read, pread, pread64, readlink, readlinkat, getcwd, confstr,
getgroups, ttyname_r, getlogin_r, gethostname, getdomainname): Call
__*_chk_warn instead of __*_chk if compile time detectable overflow
is found.
(__getgroups_chk): Rename argument to __listlen from listlen.
(__getwd_alias): Rename to...
(__getwd_warn): ... this. Add __warnattr.
(getwd): Call __getwd_warn instead of __getwd_alias.
* wcsmbs/bits/wchar2.h (__wmemcpy_chk_warn, __wmemmove_chk_warn,
__wmempcpy_chk_warn, __wmemset_chk_warn, __wcsncpy_chk_warn,
__wcpncpy_chk_warn, __fgetws_chk_warn, __fgetws_unlocked_chk_warn,
__mbsrtowcs_chk_warn, __wcsrtombs_chk_warn, __mbsnrtowcs_chk_warn,
__wcsnrtombs_chk_warn): New aliases with __warnattr.
(wmemcpy, wmemmove, wmempcpy, wmemset, mbsrtowcs, wcsrtombs,
mbsnrtowcs, wcsnrtombs): Call __*_chk_warn instead of __*_chk if
compile time detectable overflow is found.
(wcsncpy, wcpncpy): Likewise. For constant __n fix check whether
to use __*_chk or not.
(fgetws, fgetws_unlocked): Divide __bos by sizeof (wchar_t), both
in comparisons which function should be called and in __*_chk*
arguments. Call __*_chk_warn instead of __*_chk if compile time
detectable overflow is found.
(swprintf, vswprintf): Divide __bos by sizeof (wchar_t) in
__*_chk argument.
* debug/tst-chk1.c (do_test): Add a few more tests.
* rt/Makefile (headers): Add bits/mqueue2.h.
* rt/mqueue.h: Include bits/mqueue2.h if -D_FORTIFY_SOURCE=2,
optimizing with GCC and __va_arg_pack_len is defined.
* rt/bits/mqueue2.h: New file.
* rt/mq_open.c (__mq_open): Renamed from mq_open.
(mq_open): New strong_alias.
(__mq_open_2): New function.
* sysdeps/unix/sysv/linux/mq_open.c (__mq_open): Renamed from mq_open.
(mq_open): New strong_alias.
(__mq_open_2): New function.
* debug/Versions (libc): Export __fortify_fail@@GLIBC_PRIVATE.
* Versions.def (librt): Add GLIBC_2.7 version.
* debug/fortify_fail.c (__fortify_fail): Add libc_hidden_def.
* include/stdio.h (__fortify_fail): Add libc_hidden_proto.
* misc/sys/cdefs.h (__errordecl, __va_arg_pack_len): Define.
* io/fcntl.h: Include bits/fcntl2.h when __va_arg_pack_len
is defined rather than when not C++.
* io/bits/fcntl2.h (__open_alias, __open64_alias, __openat_alias,
__openat64_alias): New redirects.
(__open_too_many_args, __open_missing_mode, __open64_too_many_args,
__open64_missing_mode, __openat_too_many_args, __openat_missing_mode,
__openat64_too_many_args, __openat64_missing_mode): New __errordecls.
(open, open64, openat, openat64): Rewrite as __extern_always_inline
functions instead of function-like macros.
