PR c++/89217 - ICE with list-initialization in range-based for loop.

* constexpr.c (unshare_constructor): No longer static.
	* cp-tree.h (unshare_constructor): Declare.
	* semantics.c (finish_compound_literal): When dealing with a
	non-dependent expression in a template, return the original
	expression.  Pass LOOKUP_NO_NARROWING to digest_init_flags.

	* g++.dg/cpp0x/range-for37.C: New test.

From-SVN: r268969

gcc/cp/ChangeLog

@@ -1,3 +1,12 @@
+2019-02-17  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/89217 - ICE with list-initialization in range-based for loop.
+	* constexpr.c (unshare_constructor): No longer static.
+	* cp-tree.h (unshare_constructor): Declare.
+	* semantics.c (finish_compound_literal): When dealing with a
+	non-dependent expression in a template, return the original
+	expression.  Pass LOOKUP_NO_NARROWING to digest_init_flags.
+
 2019-02-13  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/89297 - ICE with OVERLOAD in template.

gcc/cp/constexpr.c

@@ -1318,7 +1318,7 @@ find_constructor (tree *tp, int *walk_subtrees, void *)
 /* If T is a CONSTRUCTOR or an expression that has a CONSTRUCTOR node as a
    subexpression, return an unshared copy of T.  Otherwise return T.  */
 
-static tree
+tree
 unshare_constructor (tree t)
 {
   tree ctor = walk_tree (&t, find_constructor, NULL, NULL);

gcc/cp/cp-tree.h

@@ -7710,6 +7710,7 @@ extern void explain_invalid_constexpr_fn        (tree);
 extern vec<tree> cx_error_context               (void);
 extern tree fold_sizeof_expr			(tree);
 extern void clear_cv_and_fold_caches		(void);
+extern tree unshare_constructor			(tree);
 
 /* In cp-ubsan.c */
 extern void cp_ubsan_maybe_instrument_member_call (tree);

gcc/cp/semantics.c

@@ -2796,17 +2796,31 @@ finish_compound_literal (tree type, tree compound_literal,
 	  return error_mark_node;
       }
 
-  if (instantiation_dependent_expression_p (compound_literal)
-      || dependent_type_p (type))
+  /* Used to hold a copy of the compound literal in a template.  */
+  tree orig_cl = NULL_TREE;
+
+  if (processing_template_decl)
     {
-      TREE_TYPE (compound_literal) = type;
+      const bool dependent_p
+	= (instantiation_dependent_expression_p (compound_literal)
+	   || dependent_type_p (type));
+      if (dependent_p)
+	/* We're about to return, no need to copy.  */
+	orig_cl = compound_literal;
+      else
+	/* We're going to need a copy.  */
+	orig_cl = unshare_constructor (compound_literal);
+      TREE_TYPE (orig_cl) = type;
       /* Mark the expression as a compound literal.  */
-      TREE_HAS_CONSTRUCTOR (compound_literal) = 1;
+      TREE_HAS_CONSTRUCTOR (orig_cl) = 1;
       /* And as instantiation-dependent.  */
-      CONSTRUCTOR_IS_DEPENDENT (compound_literal) = true;
+      CONSTRUCTOR_IS_DEPENDENT (orig_cl) = dependent_p;
       if (fcl_context == fcl_c99)
-	CONSTRUCTOR_C99_COMPOUND_LITERAL (compound_literal) = 1;
-      return compound_literal;
+	CONSTRUCTOR_C99_COMPOUND_LITERAL (orig_cl) = 1;
+      /* If the compound literal is dependent, we're done for now.  */
+      if (dependent_p)
+	return orig_cl;
+      /* Otherwise, do go on to e.g. check narrowing.  */
     }
 
   type = complete_type (type);
@@ -2842,8 +2856,18 @@ finish_compound_literal (tree type, tree compound_literal,
       if (type == error_mark_node)
 	return error_mark_node;
     }
-  compound_literal = digest_init_flags (type, compound_literal, LOOKUP_NORMAL,
+  compound_literal = digest_init_flags (type, compound_literal,
+					LOOKUP_NORMAL | LOOKUP_NO_NARROWING,
 					complain);
+  /* If we're in a template, return the original compound literal.  */
+  if (orig_cl)
+    {
+      if (!VECTOR_TYPE_P (type))
+	return get_target_expr_sfinae (orig_cl, complain);
+      else
+	return orig_cl;
+    }
+
   if (TREE_CODE (compound_literal) == CONSTRUCTOR)
     {
       TREE_HAS_CONSTRUCTOR (compound_literal) = true;

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2019-02-17  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/89217 - ICE with list-initialization in range-based for loop.
+	* g++.dg/cpp0x/range-for37.C: New test.
+
 2019-02-16  David Malcolm  <dmalcolm@redhat.com>
 
 	PR c++/88680

gcc/testsuite/g++.dg/cpp0x/range-for37.C

@@ -0,0 +1,24 @@
+// PR c++/89217
+// { dg-do compile { target c++11 } }
+
+struct R {};
+
+struct C
+{
+    R* begin() const { return &r; }
+    R* end() const { return &r; }
+
+    R& r;
+};
+
+struct S
+{
+    void f1() { f2<true>(); }
+    R& r;
+
+    template<bool>
+    void f2()
+    {
+        for (auto i : C{r}) {}
+    }
+};