Re: [C++ PATCH] Fix parser ICE with [[...]] and [[unused,...]] (PR c++/77637)

[Jason Merrill]

OK.

On Mon, Sep 19, 2016 at 5:50 PM, Jakub Jelinek  wrote:
> Hi!
>
> As the testcase shows, while the grammar has
> attribute-list:
>   attribute[opt]
>   attribute-list , attribute[opt]
>   attribute ...
>   attribute-list , attribute ...
> we are actually parsing it as if the last 2 lines were
>   attribute[opt] ...
>   attribute-list , attribute[opt] ...
> and ICEing when there is no attribute.
> Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
> trunk/6.3?
>
> 2016-09-19  Jakub Jelinek  
>
> PR c++/77637
> * parser.c (cp_parser_std_attribute_list): Reject ... without
> preceding attribute.
>
> * g++.dg/cpp0x/gen-attrs-62.C: New test.
>
> --- gcc/cp/parser.c.jj  2016-09-16 22:19:39.0 +0200
> +++ gcc/cp/parser.c 2016-09-19 10:33:51.481904739 +0200
> @@ -24220,8 +24220,12 @@ cp_parser_std_attribute_list (cp_parser
>if (token->type == CPP_ELLIPSIS)
> {
>   cp_lexer_consume_token (parser->lexer);
> - TREE_VALUE (attribute)
> -   = make_pack_expansion (TREE_VALUE (attribute));
> + if (attribute == NULL_TREE)
> +   error_at (token->location,
> + "expected attribute before %<...%>");
> + else
> +   TREE_VALUE (attribute)
> + = make_pack_expansion (TREE_VALUE (attribute));
>   token = cp_lexer_peek_token (parser->lexer);
> }
>if (token->type != CPP_COMMA)
> --- gcc/testsuite/g++.dg/cpp0x/gen-attrs-62.C.jj2016-09-19 
> 10:37:59.414772726 +0200
> +++ gcc/testsuite/g++.dg/cpp0x/gen-attrs-62.C   2016-09-19 10:37:28.0 
> +0200
> @@ -0,0 +1,5 @@
> +// PR c++/77637
> +// { dg-do compile { target c++11 } }
> +
> +int [[...]] a; // { dg-error "expected attribute before '...'" }
> +int [[,,...]] b;   // { dg-error "expected attribute before '...'" }
>
> Jakub

[C++ PATCH] Fix parser ICE with [[...]] and [[unused,...]] (PR c++/77637)

[Jakub Jelinek]

Hi!

As the testcase shows, while the grammar has
attribute-list:
  attribute[opt]
  attribute-list , attribute[opt]
  attribute ...
  attribute-list , attribute ...
we are actually parsing it as if the last 2 lines were
  attribute[opt] ...
  attribute-list , attribute[opt] ...
and ICEing when there is no attribute.
Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
trunk/6.3?

2016-09-19  Jakub Jelinek  

PR c++/77637
* parser.c (cp_parser_std_attribute_list): Reject ... without
preceding attribute.

* g++.dg/cpp0x/gen-attrs-62.C: New test.

--- gcc/cp/parser.c.jj  2016-09-16 22:19:39.0 +0200
+++ gcc/cp/parser.c 2016-09-19 10:33:51.481904739 +0200
@@ -24220,8 +24220,12 @@ cp_parser_std_attribute_list (cp_parser
   if (token->type == CPP_ELLIPSIS)
{
  cp_lexer_consume_token (parser->lexer);
- TREE_VALUE (attribute)
-   = make_pack_expansion (TREE_VALUE (attribute));
+ if (attribute == NULL_TREE)
+   error_at (token->location,
+ "expected attribute before %<...%>");
+ else
+   TREE_VALUE (attribute)
+ = make_pack_expansion (TREE_VALUE (attribute));
  token = cp_lexer_peek_token (parser->lexer);
}
   if (token->type != CPP_COMMA)
--- gcc/testsuite/g++.dg/cpp0x/gen-attrs-62.C.jj2016-09-19 
10:37:59.414772726 +0200
+++ gcc/testsuite/g++.dg/cpp0x/gen-attrs-62.C   2016-09-19 10:37:28.0 
+0200
@@ -0,0 +1,5 @@
+// PR c++/77637
+// { dg-do compile { target c++11 } }
+
+int [[...]] a; // { dg-error "expected attribute before '...'" }
+int [[,,...]] b;   // { dg-error "expected attribute before '...'" }

Jakub