On Wed, Nov 21, 2018 at 01:26:13AM +0000, Ramsay Jones wrote:
>
>
> On 21/11/2018 00:12, Luc Van Oostenryck wrote:
> > On Tue, Nov 20, 2018 at 01:06:23AM +0100, Luc Van Oostenryck wrote:
> >> On Mon, Nov 19, 2018 at 08:51:33PM +0000, Ramsay Jones wrote:
> >>>
> >>> The dump_macros() function fails to correctly output the definition of
> >>> macros that have a variable argument list. For example, the following
> >>> macros:
> >>>
> >>> #define unlocks(...) annotate(unlock_func(__VA_ARGS__))
> >>> #define apply(x,...) x(__VA_ARGS__)
> >>>
> >>> are output like so:
> >>>
> >>> #define unlocks(__VA_ARGS__) annotate(unlock_func(__VA_ARGS__))
> >>> #define apply(x,__VA_ARGS__) x(__VA_ARGS__)
> >>>
> >>> Add the code necessary to print the ellipsis in the argument list to the
> >>> dump_macros() function and add the above macros to the 'dump-macros.c'
> >>> test file.
> >>>
> >>> Signed-off-by: Ramsay Jones <ramsay@xxxxxxxxxxxxxxxxxxxx>
> >>> ---
> >>> pre-process.c | 11 ++++++++++-
> >>> validation/preprocessor/dump-macros.c | 5 +++++
> >>> 2 files changed, 15 insertions(+), 1 deletion(-)
> >>>
> >>> diff --git a/pre-process.c b/pre-process.c
> >>> index 7b76c65..418b8ee 100644
> >>> --- a/pre-process.c
> >>> +++ b/pre-process.c
> >>> @@ -2167,6 +2167,12 @@ struct token * preprocess(struct token *token)
> >>> return token;
> >>> }
> >>>
> >>> +static int is_VA_ARGS_token(struct token *token)
> >>> +{
> >>> + return (token_type(token) == TOKEN_IDENT) &&
> >>> + (token->ident == &__VA_ARGS___ident);
> >>> +}
> >>> +
> >>> static void dump_macro(struct symbol *sym)
> >>> {
> >>> int nargs = sym->arglist ? sym->arglist->count.normal : 0;
> >>> @@ -2182,7 +2188,10 @@ static void dump_macro(struct symbol *sym)
> >>> for (; !eof_token(token); token = token->next) {
> >>> if (token_type(token) == TOKEN_ARG_COUNT)
> >>> continue;
> >>> - printf("%s%s", sep, show_token(token));
> >>> + if (is_VA_ARGS_token(token))
> >>> + printf("%s...", sep);
> >>> + else
> >>> + printf("%s%s", sep, show_token(token));
> >>
> >> I'm wondering what is displayed by:
> >> show_ident(&__VA_ARGS___ident);
> >>
> >> I would much prefer to adjust show_ident()/show_token() and keep
> >> the code here generic.
> >
> > Mmmm, I looked at this one and what you've done here is the best.
> > I don't understand exactly why but for arguments the token
> > SPECIAL_ELLIPSIS is, at some stage, changed into a VA_ARGS ident.
>
> Heh, I'm having a weird flashback! I don't quite remember the details,
> but I was convinced the parse_arguments() (pre-process.c #1087) function
> was wrong, but I got lost several times in the debugger, so gave up!
>
> I thought a normal return would come from the condition at line 1123,
> which would leave the SPECIAL_ELLIPSIS token alone, rather than from
> the conditional at line 1143, which replaces it with VA_ARGS. ;-)
>
> It is possible that SPECIAL_ELLIPSIS is not _always_ replaced with
> VA_ARGS, and the above should still work. However, I may have given up
> too easily. :)
Yes, but this condition is only reached if you have something like:
#define m(x ...)
and then either it's an error (no ending ')' ) or the ellipsis is
replaced by TOKEN_ARG_COUNT. OTOH, the condition at line 1143 is
reached when you have something like:
#define m(x,...)
or
#define m(...)
So, I think the function is correct and the ellipses are always
replaced in non-erroneous cases (and the replacement is needed
for current processing).
-- Luc
