From 1be7bf7dab86d2fb33561b7eac1d2f527aa98b2c Mon Sep 17 00:00:00 2001
From: Nathan Sidwell <nathan@acm.org>
Date: Fri, 11 Sep 2020 08:23:32 -0700
Subject: [PATCH] objc++: Always pop scope with method definitions [PR97015]

Syntax errors in method definition lists could leave us in a function
scope.  My recent change for block scope externs didn't like that.
This reimplements the parsing loop to finish the method definition we
started.  AFAICT the original code was attempting to provide some
error recovery.  Also while there, simply do the token peeking at the
top of the loop, rather than at the two(!) ends.

	gcc/cp/
	* parser.c (cp_parser_objc_method_definition_list): Reimplement
	loop, make sure we pop scope.
	gcc/testsuite/
	* obj-c++.dg/syntax-error-9.mm: Adjust expected errors.
---
 gcc/cp/parser.c                            | 61 +++++++++-------------
 gcc/testsuite/obj-c++.dg/syntax-error-9.mm |  2 +-
 2 files changed, 27 insertions(+), 36 deletions(-)

diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index fed16895b42..fba3fcc0c4c 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -32980,44 +32980,42 @@ cp_parser_objc_method_prototype_list (cp_parser* parser)
 static void
 cp_parser_objc_method_definition_list (cp_parser* parser)
 {
-  cp_token *token = cp_lexer_peek_token (parser->lexer);
-
-  while (token->keyword != RID_AT_END && token->type != CPP_EOF)
+  for (;;)
     {
-      tree meth;
+      cp_token *token = cp_lexer_peek_token (parser->lexer);
 
-      if (token->type == CPP_PLUS || token->type == CPP_MINUS)
+      if (token->keyword == RID_AT_END)
 	{
-	  cp_token *ptk;
-	  tree sig, attribute;
-	  bool is_class_method;
-	  if (token->type == CPP_PLUS)
-	    is_class_method = true;
-	  else
-	    is_class_method = false;
+	  cp_lexer_consume_token (parser->lexer);  /* Eat '@end'.  */
+	  break;
+	}
+      else if (token->type == CPP_EOF)
+	{
+	  cp_parser_error (parser, "expected %<@end%>");
+	  break;
+	}
+      else if (token->type == CPP_PLUS || token->type == CPP_MINUS)
+	{
+	  bool is_class_method = token->type == CPP_PLUS;
+
 	  push_deferring_access_checks (dk_deferred);
-	  sig = cp_parser_objc_method_signature (parser, &attribute);
+	  tree attribute;
+	  tree sig = cp_parser_objc_method_signature (parser, &attribute);
 	  if (sig == error_mark_node)
+	    cp_parser_skip_to_end_of_block_or_statement (parser);
+	  else
 	    {
-	      cp_parser_skip_to_end_of_block_or_statement (parser);
-	      token = cp_lexer_peek_token (parser->lexer);
-	      continue;
-	    }
-	  objc_start_method_definition (is_class_method, sig, attribute,
-					NULL_TREE);
+	      objc_start_method_definition (is_class_method, sig,
+					    attribute, NULL_TREE);
 
-	  /* For historical reasons, we accept an optional semicolon.  */
-	  if (cp_lexer_next_token_is (parser->lexer, CPP_SEMICOLON))
-	    cp_lexer_consume_token (parser->lexer);
+	      /* For historical reasons, we accept an optional semicolon.  */
+	      if (cp_lexer_next_token_is (parser->lexer, CPP_SEMICOLON))
+		cp_lexer_consume_token (parser->lexer);
 
-	  ptk = cp_lexer_peek_token (parser->lexer);
-	  if (!(ptk->type == CPP_PLUS || ptk->type == CPP_MINUS
-		|| ptk->type == CPP_EOF || ptk->keyword == RID_AT_END))
-	    {
 	      perform_deferred_access_checks (tf_warning_or_error);
 	      stop_deferring_access_checks ();
-	      meth = cp_parser_function_definition_after_declarator (parser,
-								     false);
+	      tree meth
+		= cp_parser_function_definition_after_declarator (parser, false);
 	      pop_deferring_access_checks ();
 	      objc_finish_method_definition (meth);
 	    }
@@ -33037,15 +33035,8 @@ cp_parser_objc_method_definition_list (cp_parser* parser)
       else
 	/* Allow for interspersed non-ObjC++ code.  */
 	cp_parser_objc_interstitial_code (parser);
-
-      token = cp_lexer_peek_token (parser->lexer);
     }
 
-  if (token->type != CPP_EOF)
-    cp_lexer_consume_token (parser->lexer);  /* Eat '@end'.  */
-  else
-    cp_parser_error (parser, "expected %<@end%>");
-
   objc_finish_implementation ();
 }
 
diff --git a/gcc/testsuite/obj-c++.dg/syntax-error-9.mm b/gcc/testsuite/obj-c++.dg/syntax-error-9.mm
index ae104e5c140..1876c32dd20 100644
--- a/gcc/testsuite/obj-c++.dg/syntax-error-9.mm
+++ b/gcc/testsuite/obj-c++.dg/syntax-error-9.mm
@@ -1,3 +1,3 @@
 @implementation SaturnDoc /* { dg-warning "cannot find interface declaration" } */
 - read: (void*)aStream ggg /* { dg-error "expected .:. at end of input" } */
-/* { dg-error "-:expected ..end. at end of input" "" { target *-*-* } .+1 } */
+/* { dg-error "-:expected ..*. at end of input" "" { target *-*-* } .+1 } */
-- 
2.30.2