* cppinit.c (builtin_array): Update.

        (init_builtins): Flag builtins to warn if redefined or
        undefined.  Define __GXX_WEAK as a normal macro.
        * cpplib.c (do_undef): Warn if flagged NODE_WARN.
        * cpplib.h (NODE_WARN): New flag.
        * cppmacro.c (builtin_macro): Remove handling of __GXX_WEAK__.
        Handle __STDC__ as a builtin only on Solaris.
        (warn_of_redefinition): Renamed from check_macro_definition.
        Reverse sense of test.  Always warn if NODE_WARN.
        (_cpp_create_definition): Use warn_of_redefinition.  Flag
        any macro beginning with "__STDC_" to require a mandatory
        warning if redefined or undefined.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@40053 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 16 insertions, 6 deletions

diff --git a/gcc/cppinit.c b/gcc/cppinit.c
index 22ce18df1e3..d8efb4b559c 100644
--- a/gcc/cppinit.c
+++ b/gcc/cppinit.c
@@ -607,7 +607,9 @@ cpp_destroy (pfile)
 /* This structure defines one built-in identifier.  A node will be
    entered in the hash table under the name NAME, with value VALUE (if
    any).  If flags has OPERATOR, the node's operator field is used; if
-   flags has BUILTIN the node's builtin field is used.
+   flags has BUILTIN the node's builtin field is used.  Macros that are
+   known at build time should not be flagged BUILTIN, as then they do
+   not appear in macro dumps with e.g. -dM or -dD.
 
    Two values are not compile time constants, so we tag
    them in the FLAGS field instead:
@@ -632,7 +634,6 @@ struct builtin
 #define OPERATOR  	0x10
 
 #define B(n, t)       { U n, 0, t, 0, BUILTIN, sizeof n - 1 }
-#define BC(n, t)      { U n, 0, t, 0, BUILTIN | CPLUS, sizeof n - 1 }
 #define C(n, v)       { U n, v, 0, 0, 0, sizeof n - 1 }
 #define X(n, f)       { U n, 0, 0, 0, f, sizeof n - 1 }
 #define O(n, c, f)    { U n, 0, 0, c, OPERATOR | f, sizeof n - 1 }
@@ -644,8 +645,6 @@ static const struct builtin builtin_array[] =
   B("__BASE_FILE__",	 BT_BASE_FILE),
   B("__LINE__",		 BT_SPECLINE),
   B("__INCLUDE_LEVEL__", BT_INCLUDE_LEVEL),
-  B("__STDC__",		 BT_STDC),
-  BC("__GXX_WEAK__",     BT_WEAK),
 
   X("__VERSION__",		VERS),
   X("__USER_LABEL_PREFIX__",	ULP),
@@ -663,6 +662,11 @@ static const struct builtin builtin_array[] =
 #ifndef NO_BUILTIN_WINT_TYPE
   C("__WINT_TYPE__",		WINT_TYPE),
 #endif
+#ifdef STDC_0_IN_SYSTEM_HEADERS
+  B("__STDC__",		 BT_STDC),
+#else
+  C("__STDC__",		 "1"),
+#endif
 
   /* Named operators known to the preprocessor.  These cannot be #defined
      and always have their stated meaning.  They are treated like normal
@@ -714,7 +718,7 @@ init_builtins (pfile)
 	  else
 	    {
 	      hp->type = NT_MACRO;
-	      hp->flags |= NODE_BUILTIN;
+	      hp->flags |= NODE_BUILTIN | NODE_WARN;
 	      hp->value.builtin = b->builtin;
 	    }
 	}
@@ -746,7 +750,13 @@ init_builtins (pfile)
     }
 
   if (CPP_OPTION (pfile, cplusplus))
-    _cpp_define_builtin (pfile, "__cplusplus 1");
+    {
+      _cpp_define_builtin (pfile, "__cplusplus 1");
+      if (SUPPORTS_ONE_ONLY)
+	_cpp_define_builtin (pfile, "__GXX_WEAK__ 1");
+      else
+	_cpp_define_builtin (pfile, "__GXX_WEAK__ 0");
+    }
   if (CPP_OPTION (pfile, objc))
     _cpp_define_builtin (pfile, "__OBJC__ 1");