flags.h: Declare warning flag warn_system_headers.


2000-09-25  Branko Cibej  <branko.cibej@hermes.si>

        * flags.h:  Declare warning flag warn_system_headers.
        * toplev.c:  Define it.
        (W_options): Add option -Wsystem-headers.
        * diagnostic.c (count_error): Test warn_system_headers.
        * invoke.texi:  Add description for -Wsystem-headers.
	* cpplib.h (cpp_options): New member warn_system_headers.
	* cpphash.h (CPP_PEDANTIC, CPP_WTRADITIONAL): Don't test
	CPP_IN_SYSTEM_HEADER.
	* cpplib.c (do_import, do_pragma_once): Likewise.
	* cpperror.c (_cpp_begin_message): Test warn_system_headers
	and CPP_IN_SYSTEM_HEADER.
	* cppinit.c (handle_option): Recognize -Wsystem_headers.
	(print_help): Describe -Wsystem_headers.
	* cpplex.c (lex_line): Reorganize condition so that warnings
	about C++ comments in system headers can be enabled. Remove
	label do_line_comment.

From-SVN: r36636
diff --git a/gcc/cpplib.c b/gcc/cpplib.c
index d6fcf9bf..0616e8a 100644
--- a/gcc/cpplib.c
+++ b/gcc/cpplib.c
@@ -383,8 +383,7 @@
   const U_CHAR *str;
   int ab;
 
-  if (CPP_OPTION (pfile, warn_import)
-      && !CPP_IN_SYSTEM_HEADER (pfile) && !pfile->import_warning)
+  if (!pfile->import_warning && CPP_OPTION (pfile, warn_import))
     {
       pfile->import_warning = 1;
       cpp_warning (pfile,
@@ -801,9 +800,8 @@
 
   /* Allow #pragma once in system headers, since that's not the user's
      fault.  */
-  if (!CPP_IN_SYSTEM_HEADER (pfile))
-    cpp_warning (pfile, "#pragma once is obsolete");
-      
+  cpp_warning (pfile, "#pragma once is obsolete");
+ 
   if (CPP_PREV_BUFFER (ip) == NULL)
     cpp_warning (pfile, "#pragma once outside include file");
   else