glibc-2.2.5-allow-gcc-3.4-weakextern.patch

armlinux的交叉编译链,适合redhat9.0 嵌入式

------------
Bad patch.  Seems to cause breakages like this:
../include/libc-symbols.h:116: warning: `weak_alias' redefined
../include/libc-symbols.h:105: warning: this is the location of the previous definition
../include/libc-symbols.h:117: warning: `weak_extern' redefined
../include/libc-symbols.h:110: warning: this is the location of the previous definition
../include/libc-symbols.h:21: unterminated `#if' conditional
make[2]: *** [/home/dank/wk/crosstool-0.28-rc31/build/alpha-unknown-linux-gnu/gcc-2.95.3-glibc-2.2.5/build-glibc/csu/init-first.o] Error 1
------------

See http://sources.redhat.com/ml/libc-alpha/2003-01/msg00036.html
for the origin of the glibc-2.3.2 fix, and
http://sources.redhat.com/ml/crossgcc/2004-07/msg00169.html for the source
of this backport to glibc-2.2.5.

 Fixes gcc-3.4 optimizing out comparisons to weak external symbols in code
 like:
  if (__pthread_mutex_init != NULL)
    __pthread_mutex_init(...);

 that causes segfaults during libc init when not linked to libpthread

diff -uNr glibc-2.2.5-orig/include/libc-symbols.h glibc-2.2.5/include/libc-symbols.h
--- glibc-2.2.5-orig/include/libc-symbols.h	2001-08-03 16:02:52.000000000 -0700
+++ glibc-2.2.5/include/libc-symbols.h	2004-07-27 22:54:50.000000000 -0700
@@ -109,10 +109,7 @@
 /* Declare SYMBOL as weak undefined symbol (resolved to 0 if not defined).  */
 #  define weak_extern(symbol) _weak_extern (symbol)
 #  ifdef HAVE_ASM_WEAKEXT_DIRECTIVE
-#   define _weak_extern(symbol) asm (".weakext " __SYMBOL_PREFIX #symbol);
-#  else
-#   define _weak_extern(symbol)    asm (".weak " __SYMBOL_PREFIX #symbol);
-#  endif
+#  define _weak_extern(expr) _Pragma (#expr)
 
 # else
 
diff -uNr glibc-2.2.5-orig/resolv/res_libc.c glibc-2.2.5/resolv/res_libc.c
--- glibc-2.2.5-orig/resolv/res_libc.c	2001-02-12 12:23:34.000000000 -0800
+++ glibc-2.2.5/resolv/res_libc.c	2004-07-27 22:56:32.000000000 -0700
@@ -84,7 +84,8 @@
 
 #if SHLIB_COMPAT(libc, GLIBC_2_0, GLIBC_2_2)
 # undef res_init
-strong_alias (__res_init, __res_init_weak);
+extern int __res_init_weak (void);
 weak_extern (__res_init_weak);
+strong_alias (__res_init, __res_init_weak);
 compat_symbol (libc, __res_init_weak, res_init, GLIBC_2_0);
 #endif