libcpp: use better locations for _Pragma tokens (preprocessor/69126)

gcc/testsuite/ChangeLog:
	PR preprocessor/69126
	* c-c++-common/pr69126.c: New test case.

libcpp/ChangeLog:
	PR preprocessor/69126
	* directives.c (destringize_and_run): Add expansion_loc param; use
	it when handling unexpanded pragmas to fixup the locations of the
	synthesized tokens.
	(_cpp_do__Pragma): Add expansion_loc param and use it when calling
	destringize_and_run.
	* internal.h (_cpp_do__Pragma): Add expansion_loc param.
	* macro.c (builtin_macro): Pass expansion location of _Pragma to
	_cpp_do__Pragma.

From-SVN: r232893

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2016-01-27  David Malcolm  <dmalcolm@redhat.com>
+
+	PR preprocessor/69126
+	* c-c++-common/pr69126.c: New test case.
+
 2016-01-27  Ian Lance Taylor  <iant@google.com>
 
 	* gcc.dg/tree-ssa/ivopt_5.c: New test.

gcc/testsuite/c-c++-common/pr69126.c

@@ -0,0 +1,22 @@
+/* { dg-options "-Wunused-variable" } */
+
+#pragma GCC diagnostic push
+int f()
+{
+    _Pragma("GCC diagnostic ignored \"-Wunused-variable\"")
+    int x;
+    return 0;
+}
+#pragma GCC diagnostic pop
+
+#pragma GCC diagnostic push
+#define MACRO \
+    _Pragma("GCC diagnostic ignored \"-Wunused-variable\"") \
+    int x;
+
+int g()
+{
+    MACRO;
+    return 0;
+}
+#pragma GCC diagnostic pop

libcpp/ChangeLog

@@ -1,3 +1,15 @@
+2016-01-27  David Malcolm  <dmalcolm@redhat.com>
+
+	PR preprocessor/69126
+	* directives.c (destringize_and_run): Add expansion_loc param; use
+	it when handling unexpanded pragmas to fixup the locations of the
+	synthesized tokens.
+	(_cpp_do__Pragma): Add expansion_loc param and use it when calling
+	destringize_and_run.
+	* internal.h (_cpp_do__Pragma): Add expansion_loc param.
+	* macro.c (builtin_macro): Pass expansion location of _Pragma to
+	_cpp_do__Pragma.
+
 2016-01-14  David Malcolm  <dmalcolm@redhat.com>
 
 	PR preprocessor/69177

libcpp/directives.c

@@ -1753,7 +1753,8 @@ get__Pragma_string (cpp_reader *pfile)
 /* Destringize IN into a temporary buffer, by removing the first \ of
    \" and \\ sequences, and process the result as a #pragma directive.  */
 static void
-destringize_and_run (cpp_reader *pfile, const cpp_string *in)
+destringize_and_run (cpp_reader *pfile, const cpp_string *in,
+		     source_location expansion_loc)
 {
   const unsigned char *src, *limit;
   char *dest, *result;
@@ -1833,6 +1834,12 @@ destringize_and_run (cpp_reader *pfile, const cpp_string *in)
 	      toks = XRESIZEVEC (cpp_token, toks, maxcount);
 	    }
 	  toks[count] = *cpp_get_token (pfile);
+	  /* _Pragma is a builtin, so we're not within a macro-map, and so
+	     the token locations are set to bogus ordinary locations
+	     near to, but after that of the "_Pragma".
+	     Paper over this by setting them equal to the location of the
+	     _Pragma itself (PR preprocessor/69126).  */
+	  toks[count].src_loc = expansion_loc;
 	  /* Macros have been already expanded by cpp_get_token
 	     if the pragma allowed expansion.  */
 	  toks[count++].flags |= NO_EXPAND;
@@ -1867,14 +1874,14 @@ destringize_and_run (cpp_reader *pfile, const cpp_string *in)
 
 /* Handle the _Pragma operator.  Return 0 on error, 1 if ok.  */
 int
-_cpp_do__Pragma (cpp_reader *pfile)
+_cpp_do__Pragma (cpp_reader *pfile, source_location expansion_loc)
 {
   const cpp_token *string = get__Pragma_string (pfile);
   pfile->directive_result.type = CPP_PADDING;
 
   if (string)
     {
-      destringize_and_run (pfile, &string->val.str);
+      destringize_and_run (pfile, &string->val.str, expansion_loc);
       return 1;
     }
   cpp_error (pfile, CPP_DL_ERROR,

libcpp/internal.h

@@ -688,7 +688,7 @@ extern int _cpp_handle_directive (cpp_reader *, int);
 extern void _cpp_define_builtin (cpp_reader *, const char *);
 extern char ** _cpp_save_pragma_names (cpp_reader *);
 extern void _cpp_restore_pragma_names (cpp_reader *, char **);
-extern int _cpp_do__Pragma (cpp_reader *);
+extern int _cpp_do__Pragma (cpp_reader *, source_location);
 extern void _cpp_init_directives (cpp_reader *);
 extern void _cpp_init_internal_pragmas (cpp_reader *);
 extern void _cpp_do_file_change (cpp_reader *, enum lc_reason, const char *,

libcpp/macro.c

@@ -430,7 +430,7 @@ builtin_macro (cpp_reader *pfile, cpp_hashnode *node, source_location loc)
       if (pfile->state.in_directive)
 	return 0;
 
-      return _cpp_do__Pragma (pfile);
+      return _cpp_do__Pragma (pfile, loc);
     }
 
   buf = _cpp_builtin_macro_text (pfile, node);