Re: Bug in _VFPRINTF_R

[Artur Lipowski <LAL at pro dot onet dot pl>]

Eric Blake-1 wrote:
> Slightly optimized patch checked in:
>
> Index: libc/stdio/vfprintf.c
> ===================================================================
> RCS file: /cvs/src/src/newlib/libc/stdio/vfprintf.c,v
...
> +#ifndef __OPTIMIZE_SIZE__
> +                       /* Behavior is undefined if the user passed a
> +                          NULL string when precision is not 0.
> +                          However, if we are not optimizing for size,
> +                          we might as well mirror glibc behavior.  */
> +                       if (cp == NULL) {
>                                 cp = "(null)";
> -                               size = 6;
> +                               size = ((unsigned) prec > 6U) ? 6 : prec;
>                         }
> +#endif /* __OPTIMIZE_SIZE__ */
>  #ifdef _MB_CAPABLE
>                         else if (ch == 'S' || (flags & LONGINT)) {
...

Probaly this patch is a cause of the error when using with specific build params.
In case when the size optimization is turned on (like for me) then it leads to 
bad C syntax (an else clause without preceeding if) and thus compilation error:

arm-elf-gcc -B/home/artur/build/arm-elf/thumb/newlib/ -isystem 
/home/artur/build/arm-elf/thumb/newlib/targ-include -isystem 
/home/artur/newlib/newlib/libc/include  -mthumb -DPACKAGE_NAME=\"newlib\" 
-DPACKAGE_TARNAME=\"newlib\" -DPACKAGE_VERSION=\"1.15.0\" 
-DPACKAGE_STRING=\"newlib\ 1.15.0\" -DPACKAGE_BUGREPORT=\"\"  -I. 
-I../../../../../../newlib/newlib/libc/stdio -Os -D__NO_SYSCALLS__ 
-DNO_FLOATING_POINT -fno-builtin  -DREENTRANT_SYSCALLS_PROVIDED -D__BUFSIZ__=64 
-D__FILENAME_MAX__=32 -DNO_EXEC -DMALLOC_PROVIDED    -g -Os  -mthumb 
-fshort-enums -DINTEGER_ONLY -c 
../../../../../../newlib/newlib/libc/stdio/vfprintf.c -o lib_a-vfiprintf.o
../../../../../../newlib/newlib/libc/stdio/vfprintf.c: In function ‘_vfiprintf_r’:
../../../../../../newlib/newlib/libc/stdio/vfprintf.c:1105: error: expected 
expression before ‘else’
make[8]: *** [lib_a-vfiprintf.o] Error 1


Currently I use the following patch/hack for clean build (it is against an hour 
old CVS snapshot):

--- newlib/libc/stdio/vfprintf.c.org    2007-10-13 17:01:21.000000000 +0200
+++ newlib/libc/stdio/vfprintf.c        2007-10-13 17:03:06.000000000 +0200
@@ -1039,6 +1039,10 @@
                                cp = "(null)";
                                size = ((unsigned) prec > 6U) ? 6 : prec;
                        }
+#else /* __OPTIMIZE_SIZE__ */
+            if (0) {
+                ;
+            }
 #endif /* __OPTIMIZE_SIZE__ */
 #ifdef _MB_CAPABLE
                        else if (ch == 'S' || (flags & LONGINT)) {



Regards,
--
Artur Lipowski