re PR c++/64382 (ICE due to use of `this` inside a lambda that captures everything by ref inside a member function of a class template)

Fix PR c++/64382

	PR c++/64382
	* cp/parser.c (parsing_default_capturing_generic_lambda_in_template):
	New function.
	* cp/cp-tree.h: Declare it.
	* cp/semantics.c (finish_id_expression): Resolve names within a default
	capturing generic lambda defined within a template prior to
	instantiation to allow for captures to be added to the closure type.

	PR c++/64382
	* g++.dg/cpp1y/pr64382.C: New test.

From-SVN: r244962

gcc/cp/ChangeLog

@@ -1,3 +1,13 @@
+2017-01-27  Adam Butcher  <adam@jessamine.co.uk>
+
+	PR c++/64382
+	* cp/parser.c (parsing_default_capturing_generic_lambda_in_template):
+	New function.
+	* cp/cp-tree.h: Declare it.
+	* cp/semantics.c (finish_id_expression): Resolve names within a default
+	capturing generic lambda defined within a template prior to
+	instantiation to allow for captures to be added to the closure type.
+
 2017-01-26  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/68727

gcc/cp/cp-tree.h

@@ -6118,6 +6118,7 @@ extern bool maybe_clone_body			(tree);
 /* In parser.c */
 extern tree cp_convert_range_for (tree, tree, tree, tree, unsigned int, bool);
 extern bool parsing_nsdmi (void);
+extern bool parsing_default_capturing_generic_lambda_in_template (void);
 extern void inject_this_parameter (tree, cp_cv_quals);
 
 /* in pt.c */

gcc/cp/parser.c

@@ -20454,6 +20454,33 @@ parsing_nsdmi (void)
   return false;
 }
 
+/* Return true iff our current scope is a default capturing generic lambda
+   defined within a template.  FIXME: This is part of a workaround (see
+   semantics.c) to handle building lambda closure types correctly in templates
+   which we ultimately want to defer to instantiation time. */
+
+bool
+parsing_default_capturing_generic_lambda_in_template (void)
+{
+  if (!processing_template_decl || !current_class_type)
+    return false;
+
+  tree lam = CLASSTYPE_LAMBDA_EXPR (current_class_type);
+  if (!lam || LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (lam) == CPLD_NONE)
+    return false;
+
+  tree callop = lambda_function (lam);
+  if (!callop)
+    return false;
+
+  return (DECL_TEMPLATE_INFO (callop)
+	  && (DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (callop)) == callop)
+	  && ((current_nonlambda_class_type ()
+	       && CLASSTYPE_TEMPLATE_INFO (current_nonlambda_class_type ()))
+	      || ((current_nonlambda_function ()
+		   && DECL_TEMPLATE_INFO (current_nonlambda_function ())))));
+}
+
 /* Parse a late-specified return type, if any.  This is not a separate
    non-terminal, but part of a function declarator, which looks like
 

gcc/cp/semantics.c

@@ -3563,9 +3563,13 @@ finish_id_expression (tree id_expression,
 		    ? CP_ID_KIND_UNQUALIFIED_DEPENDENT
 		    : CP_ID_KIND_UNQUALIFIED)));
 
-      /* If the name was dependent on a template parameter, we will
-	 resolve the name at instantiation time.  */
-      if (dependent_p)
+      /* If the name was dependent on a template parameter and we're not in a
+	 default capturing generic lambda within a template, we will resolve the
+	 name at instantiation time.  FIXME: For lambdas, we should defer
+	 building the closure type until instantiation time then we won't need
+	 the extra test here.  */
+      if (dependent_p
+	  && !parsing_default_capturing_generic_lambda_in_template ())
 	{
 	  if (DECL_P (decl)
 	      && any_dependent_type_attributes_p (DECL_ATTRIBUTES (decl)))

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2017-01-27  Adam Butcher  <adam@jessamine.co.uk>
+
+	PR c++/64382
+	* g++.dg/cpp1y/pr64382.C: New test.
+
 2017-01-26  Martin Sebor  <msebor@redhat.com>
 
 	PR middle-end/78703

gcc/testsuite/g++.dg/cpp1y/pr64382.C

@@ -0,0 +1,23 @@
+// PR c++/64382
+// { dg-do compile { target c++14 } }
+
+template<typename T>
+struct my_queue
+{
+  void push(T)
+  {
+  }
+  void ice()
+  {
+    auto L = [=](auto &&v) {
+      push(v);
+    };
+    trav(L);
+  }
+  template<typename F>
+  void trav(F &&f)
+  {
+    f(T());
+  }
+};
+template struct my_queue<int>;