From mboxrd@z Thu Jan  1 00:00:00 1970
From: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Subject: Re: [PATCH v4] sparse: add support for _Static_assert
Date: Thu, 4 May 2017 04:29:27 +0200
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References: <20170503165518.7625-1-lrichard@redhat.com> <20170503235403.6i5za2wa526fmp6w@desk.local>
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To: Lance Richardson <lrichard@redhat.com>
Cc: Linux-Sparse <linux-sparse@vger.kernel.org>

On Thu, May 4, 2017 at 1:54 AM, Luc Van Oostenryck
<luc.vanoostenryck@gmail.com> wrote:
> On Wed, May 03, 2017 at 12:55:18PM -0400, Lance Richardson wrote:
>> This patch introduces support for the C11 _Static_assert() construct.
>
> Great!
>
>> diff --git a/parse.c b/parse.c
> ...
>> index b52c6ab..f1b96cc 100644
>> --- a/parse.c
>> +++ b/parse.c
>> @@ -1864,13 +1872,21 @@ static struct token *declaration_list(struct token *token, struct symbol_list **
>>  static struct token *struct_declaration_list(struct token *token, struct symbol_list **list)
>>  {
>>       while (!match_op(token, '}')) {
>> -             if (!match_op(token, ';'))
>> -                     token = declaration_list(token, list);
>> -             if (!match_op(token, ';')) {
>> -                     sparse_error(token->pos, "expected ; at end of declaration");
>> -                     break;
>> +             struct symbol *keyword = NULL;
>> +
>> +             if (token_type(token) == TOKEN_IDENT)
>> +                     keyword = lookup_keyword(token->ident, NS_KEYWORD);
>> +             if (keyword && keyword->op == &static_assert_op)
>
> Is it possible to move this test in a helper? Something like
>         static int match_static_assert(struct token *token)
>         {
>                 struct symbol *keyword;
>                 if (token_type(token) != TOKEN_IDENT)
>                         return 0;
>                 keyword = lookup_keyword(token->ident, NS_KEYWORD);
>                 return keyword && keyword->op == &static_assert_op;
>         }
>
>> @@ -2389,6 +2436,10 @@ static struct token * statement_list(struct token *token, struct statement_list
>>                       }
>>                       stmt = alloc_statement(token->pos, STMT_DECLARATION);
>>                       token = external_declaration(token, &stmt->declaration);
>> +             } else if (token_type(token) == TOKEN_IDENT &&
>> +                        (keyword = lookup_keyword(token->ident, NS_KEYWORD)) &&
>> +                        keyword->op == &static_assert_op) {
>> +                     token = parse_static_assert(token, NULL);

There is another problem here. With a few more line of context, we have:
>> @@ -2389,6 +2436,10 @@ static struct token * statement_list(struct token *token, struct statement_list
>>                       }
>>                       stmt = alloc_statement(token->pos, STMT_DECLARATION);
>>                       token = external_declaration(token, &stmt->declaration);
>> +             } else if (token_type(token) == TOKEN_IDENT &&
>> +                        (keyword = lookup_keyword(token->ident, NS_KEYWORD)) &&
>> +                        keyword->op == &static_assert_op) {
>> +                     token = parse_static_assert(token, NULL);
>>                }
>>                add_statement(list, stmt);

but when the static assert matches 'stmt' is not initialized and still added
to the statement list (with sporadic crashes).

-- Luc