From: Jakub Jelinek <jakub@redhat.com>
Date: Fri, 20 Dec 2019 17:01:08 +0000 (+0100)
Subject: backport: re PR c++/92648 (Handling of unknown attributes)
X-Git-Tag: releases/gcc-9.3.0~296
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=04b2ff5f756ff2da65afbf1101ac4bb1a698e9a6;p=thirdparty%2Fgcc.git

backport: re PR c++/92648 (Handling of unknown attributes)

	Backported from mainline
	2019-11-26  Jakub Jelinek  <jakub@redhat.com>

	PR c++/92648
	* parser.c (cp_parser_std_attribute): For unknown attributes,
	skip balanced token seq instead of trying to parse
	attribute-argument-clause as expression list.

	* g++.dg/cpp0x/gen-attrs-71.C: New test.

From-SVN: r279655
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 98aada542593..01dad30b3ef6 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -3,6 +3,11 @@
 	Backported from mainline
 	2019-11-26  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/92648
+	* parser.c (cp_parser_std_attribute): For unknown attributes,
+	skip balanced token seq instead of trying to parse
+	attribute-argument-clause as expression list.
+
 	PR c++/61414
 	* class.c (enum_to_min_precision): New hash_map.
 	(enum_min_precision): New function.
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 91702a50324f..8b5fa4cbd5ff 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -2650,6 +2650,7 @@ static bool cp_parser_init_statement_p
   (cp_parser *);
 static bool cp_parser_skip_to_closing_square_bracket
   (cp_parser *);
+static size_t cp_parser_skip_balanced_tokens (cp_parser *, size_t);
 
 /* Concept-related syntactic transformations */
 
@@ -26189,6 +26190,17 @@ cp_parser_std_attribute (cp_parser *parser, tree attr_ns)
       /* A GNU attribute that takes an identifier in parameter.  */
       attr_flag = id_attr;
 
+    const attribute_spec *as
+      = lookup_attribute_spec (TREE_PURPOSE (attribute));
+    if (as == NULL)
+      {
+	/* For unknown attributes, just skip balanced tokens instead of
+	   trying to parse the arguments.  */
+	for (size_t n = cp_parser_skip_balanced_tokens (parser, 1) - 1; n; --n)
+	  cp_lexer_consume_token (parser->lexer);
+	return attribute;
+      }
+
     vec = cp_parser_parenthesized_expression_list
       (parser, attr_flag, /*cast_p=*/false,
        /*allow_expansion_p=*/true,
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 54cf7e5feb81..57d96f0439ca 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -3,6 +3,9 @@
 	Backported from mainline
 	2019-11-26  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/92648
+	* g++.dg/cpp0x/gen-attrs-71.C: New test.
+
 	PR c++/61414
 	* g++.dg/cpp0x/enum23.C: Remove xfail.
 	* g++.dg/cpp0x/enum28.C: New test.
diff --git a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-71.C b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-71.C
new file mode 100644
index 000000000000..7876a2fba30c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-71.C
@@ -0,0 +1,7 @@
+// PR c++/92648
+// { dg-do compile { target c++11 } }
+
+int a [[gnu::no_such_attribute(![!(!)!]!,;;)]];	// { dg-warning "ignored" }
+int b [[no_such_namespace::nonexisting_attribute(linear(c, d : 2), reduction(*:e), linear(uval (f)))]];	// { dg-warning "ignored" }
+int c [[gnu::nonexisting_attribute()]];	// { dg-warning "ignored" }
+int d [[gnu::another_nonexistent_attr(1,"abcd",g+6)]];	// { dg-warning "ignored" }