re PR c/27721 (ICE using += with a function)

	PR c/27721
	* c-typeck.c (build_modify_expr): Test earlier for non-lvalues.

	* gcc.dg/lvalue-4.c: New test.

From-SVN: r115955

gcc/ChangeLog

 2006-08-05  Volker Reichelt  <reichelt@igpm.rwth-aachen.de>
 
+	PR c/27721
+	* c-typeck.c (build_modify_expr): Test earlier for non-lvalues.
+
 	PR c/28136
 	* c-parser.c (c_parser_postfix_expression_after_paren_type): Robustify.
 

gcc/c-typeck.c

@@ -3668,6 +3668,9 @@ build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
   if (TREE_CODE (lhs) == ERROR_MARK || TREE_CODE (rhs) == ERROR_MARK)
     return error_mark_node;
 
+  if (!lvalue_or_else (lhs, lv_assign))
+    return error_mark_node;
+
   STRIP_TYPE_NOPS (rhs);
 
   newrhs = rhs;
@@ -3681,9 +3684,6 @@ build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
       newrhs = build_binary_op (modifycode, lhs, rhs, 1);
     }
 
-  if (!lvalue_or_else (lhs, lv_assign))
-    return error_mark_node;
-
   /* Give an error for storing in something that is 'const'.  */
 
   if (TREE_READONLY (lhs) || TYPE_READONLY (lhstype)

gcc/testsuite/ChangeLog

 2006-08-05  Volker Reichelt  <reichelt@igpm.rwth-aachen.de>
 
+	PR c/27721
+	* gcc.dg/lvalue-4.c: New test.
+
 	PR c/28136
 	* gcc.dg/init-bad-5.c: New test.
 

gcc/testsuite/gcc.dg/lvalue-4.c

+/* PR c/27721 */
+/* { dg-do compile } */
+
+void foo()
+{
+  int i();
+  i += 0;  /* { dg-error "lvalue required" } */
+}