system.h (USE_COMMON_FOR_ONE_ONLY): Poison.

	* system.h (USE_COMMON_FOR_ONE_ONLY): Poison.
	* defaults.h (USE_COMMON_FOR_ONE_ONLY): Do not provide default.
	* config/darwin.h (USE_COMMON_FOR_ONE_ONLY): Do not define.

From-SVN: r188999

gcc/ChangeLog

+2012-06-26  Steven Bosscher  <steven@gcc.gnu.org>
+
+	* system.h (USE_COMMON_FOR_ONE_ONLY): Poison.
+	* defaults.h (USE_COMMON_FOR_ONE_ONLY): Do not provide default.
+	* config/darwin.h (USE_COMMON_FOR_ONE_ONLY): Do not define.
+
 2012-06-26  Alexandre Oliva  <aoliva@redhat.com>
 
 	* var-tracking.c (vt_add_function_parameter): Use a preserved

gcc/config/darwin.h

@@ -464,13 +464,6 @@ extern GTY(()) int darwin_ms_struct;
    links to, so there's no need for weak-ness for that.  */
 #define GTHREAD_USE_WEAK 0
 
-/* The Darwin linker imposes two limitations on common symbols: they
-   can't have hidden visibility, and they can't appear in dylibs.  As
-   a consequence, we should never use common symbols to represent
-   vague linkage. */
-#undef USE_COMMON_FOR_ONE_ONLY
-#define USE_COMMON_FOR_ONE_ONLY 0
-
 /* The Darwin linker doesn't want coalesced symbols to appear in
    a static archive's table of contents. */
 #undef TARGET_WEAK_NOT_IN_ARCHIVE_TOC

gcc/defaults.h

@@ -332,12 +332,6 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 # endif
 #endif
 
-/* Determines whether we may use common symbols to represent one-only
-   semantics (a.k.a. "vague linkage").  */
-#ifndef USE_COMMON_FOR_ONE_ONLY
-# define USE_COMMON_FOR_ONE_ONLY 1
-#endif
-
 /* By default we can assume that all global symbols are in one namespace,
    across all shared libraries.  */
 #ifndef MULTIPLE_SYMBOL_SPACES

gcc/system.h

@@ -894,7 +894,8 @@ extern void fancy_abort (const char *, int, const char *) ATTRIBUTE_NORETURN;
 	REAL_VALUE_TRUNCATE REVERSE_CONDEXEC_PREDICATES_P		   \
 	TARGET_ALIGN_ANON_BITFIELDS TARGET_NARROW_VOLATILE_BITFIELDS	   \
 	IDENT_ASM_OP UNALIGNED_SHORT_ASM_OP UNALIGNED_INT_ASM_OP	   \
-	UNALIGNED_LONG_ASM_OP UNALIGNED_DOUBLE_INT_ASM_OP
+	UNALIGNED_LONG_ASM_OP UNALIGNED_DOUBLE_INT_ASM_OP		   \
+	USE_COMMON_FOR_ONE_ONLY
 
 /* Hooks that are no longer used.  */
  #pragma GCC poison LANG_HOOKS_FUNCTION_MARK LANG_HOOKS_FUNCTION_FREE	\