c-cppbuiltin.c (c_cpp_builtins): Do not define __GXX_WEAK__ to 1 if !flag_weak.

	* c-cppbuiltin.c (c_cpp_builtins): Do not define __GXX_WEAK__ to 1
	if !flag_weak.
	* doc/cpp.texi (__DEPRECATED): Document.
	(__EXCEPTIONS): Likewise.
	(__GXX_WEAK__): Likewise.

	* g++.dg/cpp/weak.C: New test.

From-SVN: r99080

gcc/ChangeLog

 2005-05-01  Mark Mitchell  <mark@codesourcery.com>
 
+	* c-cppbuiltin.c (c_cpp_builtins): Do not define __GXX_WEAK__ to 1
+	if !flag_weak.
+	* doc/cpp.texi (__DEPRECATED): Document.
+	(__EXCEPTIONS): Likewise.
+	(__GXX_WEAK__): Likewise.
+
 	* function.c (INVOKE__main): Do not define.
 	(expand_main_function): Check HAS_INIT_SECTION when determining
 	whether or not to call __main.

gcc/c-cppbuiltin.c

@@ -328,7 +328,7 @@ c_cpp_builtins (cpp_reader *pfile)
 
   if (c_dialect_cxx ())
     {
-      if (SUPPORTS_ONE_ONLY)
+      if (flag_weak && SUPPORTS_ONE_ONLY) 
 	cpp_define (pfile, "__GXX_WEAK__=1");
       else
 	cpp_define (pfile, "__GXX_WEAK__=0");

gcc/doc/cpp.texi

@@ -2081,11 +2081,31 @@ respectively.  They exist to make the standard header given numerical limits
 work correctly.  You should not use these macros directly; instead, include
 the appropriate headers.
 
+@item __DEPRECATED
+This macro is defined, with value 1, when compiling a C++ source file
+with warnings about deprecated constructs enabled.  These warnings are
+enabled by default, but can be disabled with @option{-Wno-deprecated}.
+
+@item __EXCEPTIONS
+This macro is defined, with value 1, when compiling a C++ source file
+with exceptions enabled.  If @option{-fno-exceptions} was used when
+compiling the file, then this macro will not be defined.
+
 @item __USING_SJLJ_EXCEPTIONS__
 This macro is defined, with value 1, if the compiler uses the old
 mechanism based on @code{setjmp} and @code{longjmp} for exception
 handling.
 
+@item __GXX_WEAK__
+This macro is defined when compiling a C++ source file.  It has the
+value 1 if the compiler will use weak symbols, COMDAT sections, or
+other similar techniques to collapse symbols with ``vague linkage''
+that are defined in multiple translation units.  If the compiler will
+not collapse such symbols, this macro is defined with value 0.  In
+general, user code should not need to make use of this macro; the
+purpose of this macro is to ease implementation of the C++ runtime
+library provided with G++.
+
 @item __NEXT_RUNTIME__
 This macro is defined, with value 1, if (and only if) the NeXT runtime
 (as in @option{-fnext-runtime}) is in use for Objective-C@.  If the GNU

gcc/testsuite/ChangeLog

+2005-05-01  Mark Mitchell  <mark@codesourcery.com>
+
+	* g++.dg/cpp/weak.C: New test.
+
 2005-05-01  Zdenek Dvorak  <dvorakz@suse.cz>
 
 	* gcc.dg/tree-ssa/loop-8.c: New test.

gcc/testsuite/g++.dg/cpp/weak.C

+// { dg-options "-fno-weak" }
+
+#if __GXX_WEAK__
+#error "__GXX_WEAK__ defined when -fno-weak in use"
+#endif