re PR c/16566 (ICE with flexible arrays)

	PR c/16566
	* c-typeck.c (build_component_ref): Don't special-case
	COMPOUND_EXPR.

testsuite:
	* gcc.c-torture/compile/pr16566-1.c,
	gcc.c-torture/compile/pr16566-2.c,
	gcc.c-torture/compile/pr16566-3.c: New tests.

From-SVN: r87892

gcc/ChangeLog

+2004-09-22  Joseph S. Myers  <jsm@polyomino.org.uk>
+
+	PR c/16566
+	* c-typeck.c (build_component_ref): Don't special-case
+	COMPOUND_EXPR.
+
 2004-09-22  Frank Ch. Eigler  <fche@redhat.com>
 
 	* dominance.c (verify_dominators): Don't SEGV if recount_dominator

gcc/c-typeck.c

@@ -1452,26 +1452,6 @@ build_component_ref (tree datum, tree component)
   if (!objc_is_public (datum, component))
     return error_mark_node;
 
-  /* If DATUM is a COMPOUND_EXPR, move our reference inside it.
-     Ensure that the arguments are not lvalues; otherwise,
-     if the component is an array, it would wrongly decay to a pointer in
-     C89 mode.
-     We cannot do this with a COND_EXPR, because in a conditional expression
-     the default promotions are applied to both sides, and this would yield
-     the wrong type of the result; for example, if the components have
-     type "char".  */
-  switch (TREE_CODE (datum))
-    {
-    case COMPOUND_EXPR:
-      {
-	tree value = build_component_ref (TREE_OPERAND (datum, 1), component);
-	return build2 (COMPOUND_EXPR, TREE_TYPE (value),
-		       TREE_OPERAND (datum, 0), non_lvalue (value));
-      }
-    default:
-      break;
-    }
-
   /* See if there is a field or component with name COMPONENT.  */
 
   if (code == RECORD_TYPE || code == UNION_TYPE)

gcc/testsuite/ChangeLog

+2004-09-22  Joseph S. Myers  <jsm@polyomino.org.uk>
+
+	PR c/16566
+	* gcc.c-torture/compile/pr16566-1.c,
+	gcc.c-torture/compile/pr16566-2.c,
+	gcc.c-torture/compile/pr16566-3.c: New tests.
+
 2004-09-22  Kazu Hirata  <kazu@cs.umass.edu>
 
 	PR tree-optimization/17512

gcc/testsuite/gcc.c-torture/compile/pr16566-1.c

+/* ICE with flexible arrays in non-lvalue structures.  Bug 16566
+   (comment #3).  */
+
+struct S;
+
+struct C {
+    int i;
+    struct S *tab[];
+};
+
+struct S { struct C c; };
+
+void foo (struct S *x) {
+  foo(((void)1, x->c).tab[0]);
+}

gcc/testsuite/gcc.c-torture/compile/pr16566-2.c

+/* ICE with flexible arrays in non-lvalue structures.  Bug 16566
+   (comment #5).  */
+
+struct A
+{
+    int i;
+    int x[];
+};
+
+int foo(struct A a)
+{ 
+    return (a,a).x[0];
+}

gcc/testsuite/gcc.c-torture/compile/pr16566-3.c

+/* ICE with flexible arrays in non-lvalue structures.  Bug 16566
+   (testcase from duplicate bug 16575).  */
+
+struct S;
+struct C {
+    int i;
+    struct S *tab[];
+};
+struct S { struct C c; };
+void foo (struct S *x) {
+  ((void)1, x->c).tab[0] = 0;
+}