re PR middle-end/58344 (ICE with segfault at -O1 and above on x86_64-linux-gnu)

PR middle-end/58344
	* expr.c (expand_expr_real_1): Handle init == NULL_TREE.

	* gcc.c-torture/compile/pr58344.c: New test.

From-SVN: r206685

gcc/ChangeLog

@@ -1,5 +1,8 @@
 2014-01-16  Jakub Jelinek  <jakub@redhat.com>
 
+	PR middle-end/58344
+	* expr.c (expand_expr_real_1): Handle init == NULL_TREE.
+
 	PR target/59839
 	* config/i386/i386.c (ix86_expand_builtin): If target doesn't
 	satisfy operand 0 predicate for gathers, use a new pseudo as

gcc/expr.c

@@ -9832,7 +9832,25 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode,
 		     || TREE_CODE (array) == CONST_DECL)
 		 && (init = ctor_for_folding (array)) != error_mark_node)
 	  {
-	    if (TREE_CODE (init) == CONSTRUCTOR)
+	    if (init == NULL_TREE)
+	      {
+		tree value = build_zero_cst (type);
+		if (TREE_CODE (value) == CONSTRUCTOR)
+		  {
+		    /* If VALUE is a CONSTRUCTOR, this optimization is only
+		       useful if this doesn't store the CONSTRUCTOR into
+		       memory.  If it does, it is more efficient to just
+		       load the data from the array directly.  */
+		    rtx ret = expand_constructor (value, target,
+						  modifier, true);
+		    if (ret == NULL_RTX)
+		      value = NULL_TREE;
+		  }
+
+		if (value)
+		  return expand_expr (value, target, tmode, modifier);
+	      }
+	    else if (TREE_CODE (init) == CONSTRUCTOR)
 	      {
 		unsigned HOST_WIDE_INT ix;
 		tree field, value;

gcc/testsuite/ChangeLog

@@ -1,5 +1,8 @@
 2014-01-16  Jakub Jelinek  <jakub@redhat.com>
 
+	PR middle-end/58344
+	* gcc.c-torture/compile/pr58344.c: New test.
+
 	PR target/59839
 	* gcc.target/i386/pr59839.c: New test.
 

gcc/testsuite/gcc.c-torture/compile/pr58344.c

@@ -0,0 +1,12 @@
+/* PR middle-end/58344 */
+/* { dg-do compile } */
+
+struct U {};
+static struct U a[1];
+extern void bar (struct U);
+
+void
+foo (void)
+{
+  bar (a[0]);
+}