re PR c/35210 (gcc incorrectly allows calling function returning "const void")

	PR c/35210
	* c-typeck.c (build_function_call): Check for calling a function
	with qualified void return types.  Call require_complete_type when
	generating a trap.

testsuite:
	* gcc.dg/call-diag-2.c: New test.

From-SVN: r146324

gcc/ChangeLog

+2009-04-18  Joseph Myers  <joseph@codesourcery.com>
+
+	PR c/35210
+	* c-typeck.c (build_function_call): Check for calling a function
+	with qualified void return types.  Call require_complete_type when
+	generating a trap.
+
 2009-04-18  Jan Hubicka  <jh@suse.cz>
 
 	* cgraph.c (cgraph_make_edge, dump_cgraph_node, cgraph_set_call_stmt):

gcc/c-typeck.c

@@ -2498,7 +2498,12 @@ build_function_call (tree function, tree params)
 	trap = build2 (COMPOUND_EXPR, void_type_node, argarray[i], trap);
 
       if (VOID_TYPE_P (return_type))
-	return trap;
+	{
+	  if (TYPE_QUALS (return_type) != TYPE_UNQUALIFIED)
+	    pedwarn (input_location, 0,
+		     "function with qualified void return type called");
+	  return trap;
+	}
       else
 	{
 	  tree rhs;
@@ -2510,7 +2515,8 @@ build_function_call (tree function, tree params)
 	  else
 	    rhs = fold_convert (return_type, integer_zero_node);
 
-	  return build2 (COMPOUND_EXPR, return_type, trap, rhs);
+	  return require_complete_type (build2 (COMPOUND_EXPR, return_type,
+						trap, rhs));
 	}
     }
 
@@ -2543,7 +2549,12 @@ build_function_call (tree function, tree params)
 			       function, nargs, argarray);
 
   if (VOID_TYPE_P (TREE_TYPE (result)))
-    return result;
+    {
+      if (TYPE_QUALS (TREE_TYPE (result)) != TYPE_UNQUALIFIED)
+	pedwarn (input_location, 0,
+		 "function with qualified void return type called");
+      return result;
+    }
   return require_complete_type (result);
 }
 

gcc/testsuite/ChangeLog

 2009-04-18  Joseph Myers  <joseph@codesourcery.com>
 
+	PR c/35210
+	* gcc.dg/call-diag-2.c: New test.
+
+2009-04-18  Joseph Myers  <joseph@codesourcery.com>
+
 	PR preprocessor/39646
 	* gcc.dg/cpp/line8.c: New test.
 

gcc/testsuite/gcc.dg/call-diag-2.c

+/* Test diagnostics for calling function returning qualified void or
+   other incomplete type other than void.  PR 35210.  */
+/* { dg-do compile } */
+/* { dg-options "-pedantic-errors" } */
+
+const void f_cv (void);
+struct s f_s (void);
+void f_v (void);
+
+void g1 (void) { f_cv (); } /* { dg-error "qualified void" } */
+void g2 (void) { f_s (); } /* { dg-error "invalid use of undefined type" } */
+void g3 (void) { ((const void (*) (void)) f_v) (); } /* { dg-error "qualified void" } */
+/* { dg-warning "function called through a non-compatible type" "cast" { target *-*-* } 12 } */
+/* { dg-message "will abort" "abort" { target *-*-* } 12 } */
+void g4 (void) { ((struct s (*) (void)) f_v) (), (void) 0; } /* { dg-error "invalid use of undefined type" } */
+/* { dg-warning "function called through a non-compatible type" "cast" { target *-*-* } 15 } */
+/* { dg-message "will abort" "abort" { target *-*-* } 15 } */