PR c++/78572 - ICE with self-modifying array initializer

	* constexpr.c (cxx_eval_store_expression): The object we're
	initializing is outside the constant-expression.

From-SVN: r245511

gcc/cp/ChangeLog

 2017-02-16  Jason Merrill  <jason@redhat.com>
 
+	PR c++/78572 - ICE with self-modifying array initializer
+	* constexpr.c (cxx_eval_store_expression): The object we're
+	initializing is outside the constant-expression.
+	(cxx_eval_call_expression): Set ctx->call.
+
 	PR c++/79050 - ICE with undeduced auto and LTO
 	* decl.c (poplevel): Remove undeduced auto decls.
 

gcc/cp/constexpr.c

@@ -1635,6 +1635,7 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t,
 	  constexpr_ctx ctx_with_save_exprs = *ctx;
 	  hash_set<tree> save_exprs;
 	  ctx_with_save_exprs.save_exprs = &save_exprs;
+	  ctx_with_save_exprs.call = &new_call;
 
 	  tree jump_target = NULL_TREE;
 	  cxx_eval_constant_expression (&ctx_with_save_exprs, body,
@@ -3386,7 +3387,13 @@ cxx_eval_store_expression (const constexpr_ctx *ctx, tree t,
   /* And then find/build up our initializer for the path to the subobject
      we're initializing.  */
   tree *valp;
-  if (DECL_P (object))
+  if (object == ctx->object && VAR_P (object)
+      && DECL_NAME (object) && ctx->call == NULL)
+    /* The variable we're building up an aggregate initializer for is outside
+       the constant-expression, so don't evaluate the store.  We check
+       DECL_NAME to handle TARGET_EXPR temporaries, which are fair game.  */
+    valp = NULL;
+  else if (DECL_P (object))
     valp = ctx->values->get (object);
   else
     valp = NULL;

gcc/testsuite/g++.dg/init/array47.C

+// PR c++/78572
+
+static int array[10] = { array[3]=5, array[7]=3, };