[Tinycc-devel] RE :Re: Last two warnings

[Christian JULLIEN]

Ok I'll push my fix.

 

Working on mob using:

 

$ git clone -b mob git://repo.or.cz/tinycc.git
$ cd tinycc

I just have to do a "git pull" ?

 

Otherwise, here is the diff
diff --git a/tccpp.c b/tccpp.c
index ac01d83..f513a31 100644
--- a/tccpp.c
+++ b/tccpp.c
@@ -2807,7 +2807,8 @@ static inline int *macro_twosharps(const int *macro_str)

     /* we search the first '##' */
     for(ptr = macro_str;;) {
-        TOK_GET(&t, &ptr, &cval);
+        CValue ignored; // required by TOK_GET but not used
+        TOK_GET(&t, &ptr, &ignored);
         if (t == TOK_TWOSHARPS)
             break;
         /* nothing more to do if end of string */

> ----- Message d'origine -----
> De : "grischka" <address@hidden>
> Date mer. 13/02/2013 14:39 (GMT +01:00)
> À : "address@hidden" <address@hidden>
> Objet : Re: [Tinycc-devel] Last two warnings
>
> Christian Jullien wrote:
> > tccpp.c: In function ‘macro_subst’:
> > tccpp.c:2803:12: warning: ‘*((void *)&cval+4)’ is used uninitialized 
> > in this function [-Wuninitialized]
> > 
> > Because gcc is unable to know if we entered the first loop (which
> > possibly can initialize some cval fields), it complains on line 2840
> > that cval might be used uninitialized (by 2810 if we do not enter the
> > first loop).
> >
> > To me, the first use is only to find ## and we don't do anything
> > with cval, so it is safe to use a local declaration:
> > 
> >     /* we search the first '##' */
> >     for(ptr = macro_str;;) {
> >        CValue ignored;
> >         TOK_GET(&t, &ptr, &ignored);
> >         if (t == TOK_TWOSHARPS)
> >             break;
> >         /* nothing more to do if end of string */
> >         if (t == 0)
> >             return NULL;
> >     }
>
> Anyway, this looks like a bug in gcc.  If you still want to
> fix it in TCC, go for it.  Please move both declaration into
> their local block, then.
>
> --- grischka
>
> (who wrote:)
> > Which doesn't make neither "cval" any more initialized !?!
> > 
> > Maybe just a case of acute GCC warning hysteria.  
>
>
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