Fix building tools/widl (for bison 1.75, among others)

[Robert Shearman]

Gerald Pfeifer wrote:
> After the following change about a week ago
>
>   Rob Shearman <rob at codeweavers.com>
>   widl: Make the rules for parsing fields in structures, encapsulated unions 
>   and non-encapsulated unions more strict.
>
>   Move the rules in fields that handle empty union cases into separate
>   union rules so that they can't erroneously be accepted for structures or
>   other types of unions.
>
> I started seeing the following build failure on one older installation:
>
>   bison  -p parser_ -o parser.tab.c -d parser.y
>   parser.y:749.2-751.15: type clash (`var' `attr_list') on default action
>   parser.y:751.16: parse error, unexpected ":", expecting ";" or "|"
>   parser.y:752.35-59: $2 of `ne_union_field' has no declared type
>   parser.y:757.2-759.7: type clash (`var' `') on default action
>   parser.y:759.8: parse error, unexpected ":", expecting ";" or "|"
>   parser.y:759.45-760.50: $1 of `union_field' has no declared type
>   parser.y:759.45-761.23: $2 of `union_field' has no declared type
>   gmake: *** [parser.tab.h] Error 1
>
> It turns out that current versions of bison do not enforce the documented 
> grammer as strictly as older ones such as bison 1.75.  Fixed thusly.
>   

Oops, thanks for spotting it. Actually, I was developing on version 1.28 
and didn't get those errors so it doesn't appear to be a deliberate 
change by the bison developers.

> ChangeLog:
> Fix syntax to also work with older versions of bison.
>
> Index: tools/widl/parser.y
> ===================================================================
> RCS file: /home/wine/wine/tools/widl/parser.y,v
> retrieving revision 1.199
> diff -u -3 -p -r1.199 parser.y
> --- tools/widl/parser.y	1 May 2008 18:38:07 -0000	1.199
> +++ tools/widl/parser.y	2 May 2008 12:07:24 -0000
> @@ -747,6 +747,7 @@ field:	  m_attributes decl_spec declarat
>  ne_union_field:
>  	  s_field ';'				{ $$ = $1; }
>  	| attributes ';'			{ $$ = make_var(NULL); $$->attrs = $1; }
> +        ;
>  
>  ne_union_fields:				{ $$ = NULL; }
>  	| ne_union_fields ne_union_field	{ $$ = append_var( $1, $2 ); }
> @@ -755,6 +756,7 @@ ne_union_fields:				{ $$ = NULL; }
>  union_field:
>  	  s_field ';'				{ $$ = $1; }
>  	| ';'					{ $$ = NULL; }
> +        ;
>  
>  s_field:  m_attributes decl_spec declarator	{ $$ = $3->var;
>  						  $$->attrs = check_field_attrs($$->name, $1);
>
>   

Looks good. Please send to wine-patches.

-- 
Rob Shearman