Re: [PATCH] Centralize yacc interface names remapping (yyparse, yylex, yyerror, etc)

[Simon Marchi <simon dot marchi at ericsson dot com>]

On 16-04-15 08:28 PM, Pedro Alves wrote:
> This factors out all the yy-variables remapping to a single file,
> instead of each parser having to do the same, with different prefixes.
> 
> With this, a parser just needs to define the prefix they want and
> include yy-remap.h, which does the dirty job.
> 
> Note this renames the c_error, ada_error, etc. functions.  Writting

"Writing"

> the remapping pattern as:
> 
>  #define yyerror GDB_YY_REMAP(error)
> 
> instead of:
> 
>  #define yyerror GDB_YY_REMAP(yyerror)
> 
> would have avoided the renaming.  However, that would be problematic
> if we have a macro 'foo' in scope, when we write:
> 
>  #define yyfoo GDB_YY_REMAP(foo)
> 
> as that would expand 'foo'.
> 
> The c_yyerror etc. naming end ups indicating that this is a yacc
> related function more clearly, so feels like a good change, anyway.

Wow, it makes look really clean!  I now almost looks like it's not a hack :).

> +/* Define GDB_YY_REMAP_PREFIX to the desired remapping prefix before
> +   including this file.  */

What about adding an #ifndef/#error for GDB_YY_REMAP_PREFIX?  The error would be
clearer than what we get otherwise if a file omits defining GDB_YY_REMAP_PREFIX:

c-lang.o:(.rodata+0x578): undefined reference to `c_yyerror'
c-lang.o:(.rodata+0x6b8): undefined reference to `c_yyerror'
c-lang.o:(.rodata+0x7f8): undefined reference to `c_yyerror'
c-lang.o:(.rodata+0x938): undefined reference to `c_yyerror'
objc-lang.o:(.rodata+0x558): undefined reference to `c_yyerror'
opencl-lang.o:(.rodata+0x5f8): more undefined references to `c_yyerror' follow
...

> +#define GDB_YY_REMAP_2(PREFIX, YYSYM) PREFIX ## YYSYM
> +#define GDB_YY_REMAP_1(PREFIX, YYSYM) GDB_YY_REMAP_2(PREFIX, YYSYM)
> +#define GDB_YY_REMAP(YYSYM) GDB_YY_REMAP_1(GDB_YY_REMAP_PREFIX, YYSYM)
> +
> +#define yymaxdepth	GDB_YY_REMAP(yymaxdepth)
> +#define yyparse	GDB_YY_REMAP(yyparse)
> +#define yylex		GDB_YY_REMAP(yylex)
> +#define yyerror	GDB_YY_REMAP(yyerror)
> +#define yylval		GDB_YY_REMAP(yylval)
> +#define yychar		GDB_YY_REMAP(yychar)
> +#define yydebug	GDB_YY_REMAP(yydebug)
> +#define yypact		GDB_YY_REMAP(yypact)
> +#define yyr1		GDB_YY_REMAP(yyr1)
> +#define yyr2		GDB_YY_REMAP(yyr2)
> +#define yydef		GDB_YY_REMAP(yydef)
> +#define yychk		GDB_YY_REMAP(yychk)
> +#define yypgo		GDB_YY_REMAP(yypgo)
> +#define yyact		GDB_YY_REMAP(yyact)
> +#define yyexca		GDB_YY_REMAP(yyexca)
> +#define yyerrflag	GDB_YY_REMAP(yyerrflag)
> +#define yynerrs	GDB_YY_REMAP(yynerrs)
> +#define yyps		GDB_YY_REMAP(yyps)
> +#define yypv		GDB_YY_REMAP(yypv)
> +#define yys		GDB_YY_REMAP(yys)
> +#define yy_yys		GDB_YY_REMAP(yy_yys)
> +#define yystate	GDB_YY_REMAP(yystate)
> +#define yytmp		GDB_YY_REMAP(yytmp)
> +#define yyv		GDB_YY_REMAP(yyv)
> +#define yy_yyv		GDB_YY_REMAP(yy_yyv)
> +#define yyval		GDB_YY_REMAP(yyval)
> +#define yylloc		GDB_YY_REMAP(yylloc)
> +#define yyreds		GDB_YY_REMAP(yyreds)  /* With YYDEBUG defined */
> +#define yytoks		GDB_YY_REMAP(yytoks)  /* With YYDEBUG defined */
> +#define yyname		GDB_YY_REMAP(yyname)  /* With YYDEBUG defined */
> +#define yyrule		GDB_YY_REMAP(yyrule)  /* With YYDEBUG defined */
> +#define yylhs		GDB_YY_REMAP(yylhs)
> +#define yylen		GDB_YY_REMAP(yylen)
> +#define yydefred	GDB_YY_REMAP(yydefred)
> +#define yydgoto	GDB_YY_REMAP(yydgoto)
> +#define yysindex	GDB_YY_REMAP(yysindex)
> +#define yyrindex	GDB_YY_REMAP(yyrindex)
> +#define yygindex	GDB_YY_REMAP(yygindex)
> +#define yytable	GDB_YY_REMAP(yytable)
> +#define yycheck	GDB_YY_REMAP(yycheck)
> +#define yyss		GDB_YY_REMAP(yyss)
> +#define yysslim	GDB_YY_REMAP(yysslim)
> +#define yyssp		GDB_YY_REMAP(yyssp)
> +#define yystacksize	GDB_YY_REMAP(yystacksize)
> +#define yyvs		GDB_YY_REMAP(yyvs)
> +#define yyvsp		GDB_YY_REMAP(yyvsp)

Mininit:  I think these could be vertically aligned a bit better.

Otherwise, looks very good!