From: Jakub Jelinek <jakub@redhat.com>
To: Ulrich Drepper <drepper@redhat.com>
Cc: Glibc hackers <libc-hacker@sources.redhat.com>
Subject: [PATCH] Fix btowc and wctob in C++
Date: Mon, 27 Mar 2006 16:44:00 -0000 [thread overview]
Message-ID: <20060327164414.GB30252@sunsite.mff.cuni.cz> (raw)
Hi!
Doing:
#include <wchar.h>
void *p = (void *) btowc;
at -O1+ in C++ (or similarly if for whatever reason the inline isn't always
inlined) results in endless recursion:
.section .text.btowc,"axG",@progbits,btowc,comdat
.align 2
.p2align 4,,15
.weak btowc
.type btowc, @function
btowc:
jmp btowc
.size btowc, .-btowc
The optimization really relies on the GNU C extern inline behavior.
We use the same __*_alias trick in plenty of the _FORTIFY_SOURCE headers,
but none of them is used for C++ nor for non-GCC compilers.
__USE_EXTERN_INLINES implies GCC 2.7+, so we just need to check for C++.
2006-03-27 Jakub Jelinek <jakub@redhat.com>
* wcsmbs/wchar.h (btowc, wctob): Don't optimize in C++.
--- libc/wcsmbs/wchar.h.jj 2006-03-17 08:37:07.000000000 +0100
+++ libc/wcsmbs/wchar.h 2006-03-27 18:38:07.000000000 +0200
@@ -321,6 +321,7 @@ __END_NAMESPACE_C99
#ifdef __USE_EXTERN_INLINES
/* Define inline function as optimization. */
+# ifndef __cplusplus
/* We can use the BTOWC and WCTOB optimizations since we know that all
locales must use ASCII encoding for the values in the ASCII range
and because the wchar_t encoding is always ISO 10646. */
@@ -335,6 +336,7 @@ extern __inline int
__NTH (wctob (wint_t __wc))
{ return (__builtin_constant_p (__wc) && __wc >= L'\0' && __wc <= L'\x7f'
? (int) __wc : __wctob_alias (__wc)); }
+# endif
extern __inline size_t
__NTH (mbrlen (__const char *__restrict __s, size_t __n,
Jakub
next reply other threads:[~2006-03-27 16:44 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-03-27 16:44 Jakub Jelinek [this message]
2006-03-27 20:13 ` Ulrich Drepper
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