Bug#629441: /usr/bin/clang: compilation fails on MIPS due to missing _MIPS_SZPTR macro

[Aurelien Jarno]

On Thu, Dec 26, 2013 at 12:48:44AM +0000, Aníbal Monsalve Salazar wrote:
> On Thu, Dec 26, 2013 at 11:35:16AM +1100, Aníbal Monsalve Salazar wrote:
> > On Mon, Jun 06, 2011 at 08:36:26PM +0200, Aurelien Jarno wrote:
> >> clone 601645 -1
> >> reopen -1
> >> reassign -1 clang 2.9-1
> >> thanks
> >> 
> >> Hi,
> >> 
> >> On Wed, Oct 27, 2010 at 10:32:01PM -0400, Mark Heily wrote:
> >>> Package: clang
> >>> Version: 2.7-3
> >>> Severity: normal
> >>> File: /usr/bin/clang
> >>> 
> >>> clang is unable to compile a trivial program on MIPS due to a glibc
> >>> dependency on GCC-specific macros. Here is a command that
> >>> demonstrates the failure:
> >>> 
> >>> $ echo '#include <stdlib.h>' | clang -x c -
> >>> clang: warning: unknown platform, assuming -mfloat-abi=soft
> >>> In file included from <stdin>:1:
> >>> In file included from /usr/include/stdlib.h:320:
> >>> In file included from /usr/include/sys/types.h:31:
> >>> /usr/include/bits/types.h:128:3: error: #error
> >>> 
> >>> The problem is that glibc expects the macro _MIPS_SZPTR to be
> >>> defined by the compiler. Clang does not appear to define this macro.
> >>> Glibc uses _MIPS_SZPTR to set the value of __WORDSIZE, so you can
> >>> workaround the compilation issue like this:
> >>> 
> >>>     printf "#define _MIPS_SZPTR 32\n#include <stdlib.h>\n" | clang -x c -
> >>> 
> >>> The Linux kernel sources mention several other MIPS-related macros
> >>> that are specific to GCC and may not be implemented by other
> >>> compilers [1].
> >> 
> >> This bug has been workaround in eglibc 2.13-5 by using another way to
> >> define __WORDSIZE on clang.
> >> 
> >> That said after discussing with upstream, it clearly appears to be a
> >> clang issue. _MIPS_SZPTR has been defined by SGI and must be present
> >> in all compilers targeting MIPS. Some more details are given in 
> >> "MIPSpro(TM) Compiling and Performance Tuning Guide" (SGI's document 
> >> #007-2360-008).
> >> 
> >> I am therefore cloning and reassigning this bug to clang. I'll keep the
> >> workaround in eglibc until the problem is solved on the clang side.
> > 
> > Hello Aurelien,
> > 
> > I just closed #599984.
> > 
> > http://bugs.debian.org/599984
> > 
> > And #629441 was blocking the fix for #599984.
> > 
> > http://bugs.debian.org/629441
> > 
> > I tried your one-line clang command on mips and mipsel.
> > 
> > The mips result is below.
> > 
> >   $ uname -a
> >   Linux choco 3.10-3-r5k-ip32 #1 Debian 3.10.11-1 (2013-09-10) mips64 GNU/Linux
> > 
> >   $ echo '#include <stdlib.h>' | clang -x c -
> >   /usr/bin/ld: /tmp/--6Ek165.o: warning: linking abicalls files with non-abicalls files
> >   /usr/bin/../lib/gcc/mips-linux-gnu/4.8/../../../mips-linux-gnu/crt1.o: In function `__start':
> >   (.text+0x18): undefined reference to `main'
> >   clang: error: linker command failed with exit code 1 (use -v to see invocation)
> > 
> > And the mipsel result is below.
> > 
> >   $ uname -a
> >   Linux eladi 2.6.36-trunk-loongson-2f #1 Thu Oct 28 17:32:42 UTC 2010 mips64 GNU/Linux
> > 
> >   $ echo '#include <stdlib.h>' | clang -x c -
> >   /usr/bin/ld: /tmp/--klojkk.o: warning: linking abicalls files with non-abicalls files
> >   /usr/bin/../lib/gcc/mipsel-linux-gnu/4.8/../../../mipsel-linux-gnu/crt1.o: In function `__start':
> >   (.text+0x18): undefined reference to `main'
> >   clang: error: linker command failed with exit code 1 (use -v to see invocation)
> > 
> > Should I close #629441?

glibc has workarounded the clang bug, which didn't define correctly
_MIPS_SZPTR, so it's normal that your test works.

The test to do is the following:

$echo '_MIPS_SZPTR' | clang -E -  
# 1 "<stdin>"
# 1 "<stdin>" 1
# 1 "<built-in>" 1
# 1 "<built-in>" 3
# 154 "<built-in>" 3
# 1 "<command line>" 1
# 1 "<built-in>" 2
# 1 "<stdin>" 2
32

And you can see that _MIPS_SZPTR is correctly defined. So yes this bug
can be closed now.

-- 
Aurelien Jarno	                        GPG: 1024D/F1BCDB73
aurelien at aurel32.net                 http://www.aurel32.net