2012-02-09  Jakub Jelinek  <jakub@redhat.com>

	Backported from mainline
	2012-01-05  Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/51768
	* stmt.c (check_unique_operand_names): Don't ICE during error
	reporting if i is from labels chain.

	* c-c++-common/pr51768.c: New test.

--- gcc/stmt.c	(revision 182920)
+++ gcc/stmt.c	(revision 182921)
@@ -1253,11 +1253,11 @@ check_operand_nalternatives (tree output
 static bool
 check_unique_operand_names (tree outputs, tree inputs, tree labels)
 {
-  tree i, j;
+  tree i, j, i_name = NULL_TREE;
 
   for (i = outputs; i ; i = TREE_CHAIN (i))
     {
-      tree i_name = TREE_PURPOSE (TREE_PURPOSE (i));
+      i_name = TREE_PURPOSE (TREE_PURPOSE (i));
       if (! i_name)
 	continue;
 
@@ -1268,7 +1268,7 @@ check_unique_operand_names (tree outputs
 
   for (i = inputs; i ; i = TREE_CHAIN (i))
     {
-      tree i_name = TREE_PURPOSE (TREE_PURPOSE (i));
+      i_name = TREE_PURPOSE (TREE_PURPOSE (i));
       if (! i_name)
 	continue;
 
@@ -1282,7 +1282,7 @@ check_unique_operand_names (tree outputs
 
   for (i = labels; i ; i = TREE_CHAIN (i))
     {
-      tree i_name = TREE_PURPOSE (i);
+      i_name = TREE_PURPOSE (i);
       if (! i_name)
 	continue;
 
@@ -1297,8 +1297,7 @@ check_unique_operand_names (tree outputs
   return true;
 
  failure:
-  error ("duplicate asm operand name %qs",
-	 TREE_STRING_POINTER (TREE_PURPOSE (TREE_PURPOSE (i))));
+  error ("duplicate asm operand name %qs", TREE_STRING_POINTER (i_name));
   return false;
 }
 
--- gcc/testsuite/c-c++-common/pr51768.c	(revision 0)
+++ gcc/testsuite/c-c++-common/pr51768.c	(revision 182921)
@@ -0,0 +1,25 @@
+/* PR middle-end/51768 */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+void
+foo (void)
+{
+  asm goto ("" : : : : lab, lab, lab2, lab);	/* { dg-error "duplicate asm operand name" } */
+lab:;
+lab2:;
+}
+
+void
+bar (void)
+{
+  asm goto ("" : : [lab] "i" (0) : : lab);	/* { dg-error "duplicate asm operand name" } */
+lab:;
+}
+
+void
+baz (void)
+{
+  int x;
+  asm ("" : [lab] "=r" (x) : [lab] "r" (x));	/* { dg-error "duplicate asm operand name" } */
+}