re PR c/67730 (No warning when returning NULL in void function)

	PR c/67730
	* c-typeck.c (c_finish_return): Use the expansion point location for
	certain "return with value" warnings.

	* gcc.dg/pr67730.c: New test.

From-SVN: r228286

gcc/c/ChangeLog

+2015-09-30  Marek Polacek  <polacek@redhat.com>
+
+	PR c/67730
+	* c-typeck.c (c_finish_return): Use the expansion point location for
+	certain "return with value" warnings.
+
 2015-09-18  Manuel López-Ibáñez  <manu@gcc.gnu.org>
 
 	* c-parser.c (pragma_lex): Add loc argument.

gcc/c/c-typeck.c

@@ -9369,8 +9369,12 @@ c_finish_return (location_t loc, tree retval, tree origtype)
   bool npc = false;
   size_t rank = 0;
 
+  /* Use the expansion point to handle cases such as returning NULL
+     in a function returning void.  */
+  source_location xloc = expansion_point_location_if_in_system_header (loc);
+
   if (TREE_THIS_VOLATILE (current_function_decl))
-    warning_at (loc, 0,
+    warning_at (xloc, 0,
 		"function declared %<noreturn%> has a %<return%> statement");
 
   if (flag_cilkplus && contains_array_notation_expr (retval))
@@ -9425,10 +9429,10 @@ c_finish_return (location_t loc, tree retval, tree origtype)
     {
       current_function_returns_null = 1;
       if (TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE)
-	pedwarn (loc, 0,
+	pedwarn (xloc, 0,
 		 "%<return%> with a value, in function returning void");
       else
-	pedwarn (loc, OPT_Wpedantic, "ISO C forbids "
+	pedwarn (xloc, OPT_Wpedantic, "ISO C forbids "
 		 "%<return%> with expression, in function returning void");
     }
   else

gcc/testsuite/ChangeLog

 2015-09-30  Marek Polacek  <polacek@redhat.com>
 
+	PR c/67730
+	* gcc.dg/pr67730.c: New test.
+
+2015-09-30  Marek Polacek  <polacek@redhat.com>
+
 	PR tree-optimization/67690
 	* gcc.dg/torture/pr67690.c: New test.
 

gcc/testsuite/gcc.dg/pr67730.c

+/* PR c/67730 */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+#include <stddef.h>
+
+void
+fn1 (void)
+{
+  return NULL; /* { dg-warning "10:.return. with a value" } */
+}