Re: __attribute__((__unused__)) problem

[John Horigan]

Why not replace '/*CONSTCOND*/ 0' with a non-constant expression that is
guaranteed to be false, like 'rand() < 0'? Or if you don't want to modify
the global random seed then define yyFalse() and yyTrue().

-- john


On Wed, Apr 10, 2013 at 7:31 AM, Akim Demaille <address@hidden> wrote:

>
> Le 8 avr. 2013 à 21:14, victor khomenko <address@hidden>
> a écrit :
>
> > Dear Akim,
>
> Hi Victor,
>
> Thanks for the report.
>
> > c:\punf\picallib\parse_pi.cpp(1202) : warning C4365: 'return' :
> conversion from 'int' to 'size_t', signed/unsigned mismatch
>
> This is the second return.
>
> > static YYSIZE_T
> > yytnamerr (char *yyres, const char *yystr)
> > {
> >   […]
> >   if (! yyres)
> >     return yystrlen (yystr);
> >
> >   return yystpcpy (yyres, yystr) - yyres;
> > }
>
>
> > c:\punf\picallib\parse_pi.cpp(1657) : warning C4242: '=' : conversion
> from 'int' to 'yytype_int16', possible loss of data
>
> This is the assignment:
>
>  yysetstate:
>   *yyssp = yystate;
>
> because
>
>     yytype_int16 *yyssp;
>     int yystate;
>
> it would make sense to be more consistent here.
>
> > c:\punf\picallib\parse_pi.cpp(1662) : warning C4365: 'initializing' :
> conversion from 'int' to 'size_t', signed/unsigned mismatch
>
>       YYSIZE_T yysize = yyssp - yyss + 1;
>
> > c:\punf\picallib\parse_pi.cpp(1704) : warning C4127: conditional
> expression is constant
>
> This is because of the do {…} while (false) trick in the
> macros:
>
> # define YYSTACK_RELOCATE(Stack_alloc, Stack)                           \
>     do                                                                  \
>       {                                                                 \
>         YYSIZE_T yynewbytes;                                            \
>         YYCOPY (&yyptr->Stack_alloc, Stack, yysize);                    \
>         Stack = &yyptr->Stack_alloc;                                    \
>         yynewbytes = yystacksize * sizeof (*Stack) + YYSTACK_GAP_MAXIMUM; \
>         yyptr += yynewbytes / sizeof (*yyptr);                          \
>       }                                                                 \
>     while (YYID (0))
>
>
> > c:\punf\picallib\parse_pi.cpp(1705) : warning C4127: conditional
> expression is constant
> >
> > c:\punf\picallib\parse_pi.cpp(1706) : warning C4127: conditional
> expression is constant
> >
> > c:\punf\picallib\parse_pi.cpp(1773) : warning C4127: conditional
> expression is constant
> >
> > c:\punf\picallib\parse_pi.cpp(1826) : warning C4127: conditional
> expression is constant
> >
> > c:\punf\picallib\parse_pi.cpp(2292) : warning C4127: conditional
> expression is constant
> >
> > c:\punf\picallib\parse_pi.cpp(2344) : warning C4127: conditional
> expression is constant
>
> They are all alike.
>
> >
> > c:\punf\picallib\parse_pi.cpp(854) : warning C4505: 'yy_location_print_'
> : unreferenced local function has been removed
> >
> > c:\punf\picallib\parse_pi.cpp(2295) : warning C4702: unreachable code
> > <parse_pi.y><parse_pi.cpp>
>
> yyerrorlab:
>
>   /* Pacify compilers like GCC when the user code never invokes
>      YYERROR and the label yyerrorlab therefore never appears in user
>      code.  */
>   if (/*CONSTCOND*/ 0)
>      goto yyerrorlab;
>
>   yyerror_range[1] = yylsp[1-yylen];  <======== this line
>
> Well, it's going to be painful to address these warning.
> I don't think I will do that in 2.7.1, which I'd like to
> release soon.  They can be covered in 3.x.  I'd like to
> avoid #pragma if I can, so if you have ideas, please contribute!
>
>
>