'_ctype_' aliased to undefined symbol '_ctype_b+127'

Jeff Johnston jjohnstn@redhat.com
Thu Aug 18 22:48:00 GMT 2005

This should have been handled by the configuration check for array 
aliasing in configure.in which sets a flag in newlib.h.  If gcc fails to 
compile such code (which modern gcc versions do), then the 
_HAVE_ARRAY_ALIASING flag should be undefined when you compile ctype_.c 
and therefore you shouldn't get to that code.

FWIW: I have seen a bug in gcc4 with save-temps where the original file 
and saved-temps differed.  In my case, gcc didn't output a function it 
should have that was protected by a flag check.  The save-temps and -E 
outputs showed that the flag was indeed set as expected and so when 
compiled it output the function.  The scary thing is that I believe the 
saved-temps output was correct and the original compile was wrong.

-- Jeff J.

Shaun Jackman wrote:
> gcc complains about this line:
> extern _CONST char _ctype_[1 + 256] __attribute__ ((alias ("_ctype_b+127")));
> error: '_ctype_' aliased to undefined symbol '_ctype_b+127'
> However, if I use gcc -save-temps, I can compile the resulting
> assembler file using as. Any suggestions?
> Cheers,
> Shaun
> $ make
> ...
> gcc -m64 -I/home/sjackman/work/debian/newlib/newlib-1.13.0/_build/i686-pc-linux-gnu/64/newlib/targ-include
> -I/home/sjackman/work/debian/newlib/newlib-1.13.0/newlib/libc/include
> -DPACKAGE=\"newlib\" -DVERSION=\"1.13.0\" -I.
> -I../../../../../../newlib/libc/ctype -O2 -Wall
> -O2 -g -O2 -O2 -g -O2 -m64 -c
> ../../../../../../newlib/libc/ctype/ctype_.c  -fPIC -DPIC -o
> .libs/ctype_.o
> ../../../../../../newlib/libc/ctype/ctype_.c:91: error: '_ctype_'
> aliased to undefined symbol '_ctype_b+127'
> make[7]: *** [ctype_.lo] Error 1
> make[7]: Leaving directory
> `/home/sjackman/work/debian/newlib/newlib-1.13.0/_build/i686-pc-linux-gnu/64/newlib/libc/ctype'
> ...

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