vasprintf on DEC [was: m4-1.4.7 build feedback]

[Eric Blake]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

According to Nelson H. F. Beebe on 9/26/2006 8:51 AM:
> Machinetype:            DEC Alpha 4100-5/466 (4 21164 EV5 CPUs, 466 MHz, 2GB 
> RAM);          OSF/1 4.0F
> Remote cc version:      DEC C V5.9-005 on Digital UNIX V4.0 (Rev. 1229)
> Configure environment:  CC=cc CFLAGS="-ieee -I/usr/local/include" CXX=cxx 
> CXXFLAGS="-ieee -I/usr/local/include" LDFLAGS="-Wl,-rpath,/usr/local/lib 
> -Wl,-oldstyle_liblookup -L/usr/local/lib" LIBS="-lsnprintf" FC=f77 F77=f77
> 
> Checking ./108.format
> @ ../doc/m4.texinfo:3779: Origin of test
> ./108.format: stdout mismatch
> 3c3
> < 56790
> ---
>> f
> 
> The problem statement in the test file is this one:
> 
>       format(`%.0f', `56789.9876')

You reported the same bug against m4 1.4.5 as well.  I'm not sure why your
compiler is failing to handle %.0f correctly; m4 uses the gnulib xasprintf
module for its formatting, which, IIUC, somewhere under the hood should
result in a printf call to your libc.

> 
> I'm not sure why this outputs f instead of 56790.  m4 does not appear
> to be using the printf() library function, because this test program
> produces correct output:
> 
>       % cat fmtbug.c
>       #include <stdio.h>
>       #include <stdlib.h>
> 
>       int
>       main(void)
>       {
>           printf("%.f\n", 56789.9876);
>           printf("%.0f\n", 56789.9876);
> 
>           return (EXIT_SUCCESS);
>       }
> 
>       %  cc fmtbug.c && ./a.out
>       56790
>       56790

Even weirder.  Could you try building a test app that uses xasprintf and
links against libm4 built in m4/lib, to further debug the issue?  Is
[v]sprintf different than plain printf?

- --
Life is short - so eat dessert first!

Eric Blake             address@hidden
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.2.1 (Cygwin)
Comment: Public key at home.comcast.net/~ericblake/eblake.gpg
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFFGeFj84KuGfSFAYARAo+DAJ9XuKGRl56XtZZ3NiQaTZwY6exUUgCgljAP
jifeEFMbQHOAw2cme1vj9v8=
=wm0X
-----END PGP SIGNATURE-----