Allow Objective-c++ to recognise lambdas.

gcc/cp:

	* parser.c (cp_parser_primary_expression): If parsing an
	objective-c++ message expression fails, see if a lambda is present.
	(cp_parser_objc_message_receiver): Don't assume that, if a message
	receiver expression fails, it is a hard error.

gcc/testsuite:

	* obj-c++.dg/lambda-0.mm New.
	* obj-c++.dg/lambda-1.mm New.
	* obj-c++.dg/syntax-error-6.mm Adjust for revised error messages.

From-SVN: r219125

gcc/cp/ChangeLog

+2014-12-31  Iain Sandoe  <iain@codesourcery.com>
+
+	* parser.c (cp_parser_primary_expression): If parsing an
+	objective-c++ message expression fails, see if a lambda is present.
+	(cp_parser_objc_message_receiver): Don't assume that, if a message
+	receiver expression fails, it is a hard error.
+
 2014-12-25  Jason Merrill  <jason@redhat.com>
 
 	* pt.c (check_default_tmpl_args): Uses the parameter source

gcc/cp/parser.c

@@ -4442,10 +4442,17 @@ cp_parser_primary_expression (cp_parser *parser,
       }
 
     case CPP_OPEN_SQUARE:
-      if (c_dialect_objc ())
-        /* We have an Objective-C++ message. */
-        return cp_parser_objc_expression (parser);
       {
+	if (c_dialect_objc ())
+	  {
+	    /* We might have an Objective-C++ message. */
+	    cp_parser_parse_tentatively (parser);
+	    tree msg = cp_parser_objc_message_expression (parser);
+	    /* If that works out, we're done ... */
+	    if (cp_parser_parse_definitely (parser))
+	      return msg;
+	    /* ... else, fall though to see if it's a lambda.  */
+	  }
 	tree lam = cp_parser_lambda_expression (parser);
 	/* Don't warn about a failed tentative parse.  */
 	if (cp_parser_error_occurred (parser))
@@ -25657,14 +25664,20 @@ cp_parser_objc_message_receiver (cp_parser* parser)
   cp_parser_parse_tentatively (parser);
   rcv = cp_parser_expression (parser);
 
+  /* If that worked out, fine.  */
   if (cp_parser_parse_definitely (parser))
     return rcv;
 
+  cp_parser_parse_tentatively (parser);
   rcv = cp_parser_simple_type_specifier (parser,
 					 /*decl_specs=*/NULL,
 					 CP_PARSER_FLAGS_NONE);
 
-  return objc_get_class_reference (rcv);
+  if (cp_parser_parse_definitely (parser))
+    return objc_get_class_reference (rcv);
+  
+  cp_parser_error (parser, "objective-c++ message receiver expected");
+  return error_mark_node;
 }
 
 /* Parse the arguments and selectors comprising an Objective-C message.

gcc/testsuite/ChangeLog

 2014-12-31  Iain Sandoe  <iain@codesourcery.com>
 
+	* obj-c++.dg/lambda-0.mm New.
+	* obj-c++.dg/lambda-1.mm New.
+	* obj-c++.dg/syntax-error-6.mm Adjust for revised error messages.
+
+2014-12-31  Iain Sandoe  <iain@codesourcery.com>
+
 	* obj-c++.dg/standard-headers.mm New.
 
 2014-12-30  Jan Hubicka  <hubicka@ucw.cz>

gcc/testsuite/obj-c++.dg/lambda-0.mm

+// Contributed by Iain Sandoe <iain@codesourcery.com>, December 2014.  */
+// { dg-do compile }
+// { dg-options "-std=c++11" }
+
+
+template<class Function>
+Function thing(Function fn, int a)
+{
+  fn(a);
+  return fn;
+}
+
+int
+test (int *arr, unsigned n)
+{
+  int total = 0;
+  for (unsigned i=0; i<n; i++) {
+    int a = arr[i];
+    thing ([&total] (int a) { total += a; }, a);
+  }
+  return total;
+}

gcc/testsuite/obj-c++.dg/lambda-1.mm

+// Contributed by Iain Sandoe <iain@codesourcery.com>, December 2014.  */
+// { dg-do compile }
+// { dg-options "-std=c++11" }
+
+extern "C" {
+  int printf (const char *,...);
+}
+
+int main () 
+{
+  auto f = [] (const char *msg) -> int { printf("%s", msg); return 0; };
+  return f("Some test\n");
+}

gcc/testsuite/obj-c++.dg/syntax-error-6.mm

@@ -8,5 +8,8 @@ void FOO()
 {
   NSButton * mCopyAcrobatCB; 
 	
-  [ [ mCopyAcrobatCB state ] == 0 ] != 1;  /* { dg-error "objective\\-c\\+\\+" } */
+  [ [ mCopyAcrobatCB state ] == 0 ] != 1;  /* { dg-error "expected identifier before ... token" } */
+/* { dg-error "expected \\\'\\\{\\\' before \\\'!=\\\' token" "" { target *-*-* } 11 } */
+/* { dg-error "lambda expressions only available with" "" { target *-*-* } 11 } */
+/* { dg-error "no match for \\\'operator!=\\\' in" "" { target *-*-* } 11 } */
 }