[gettext-0.16.1] undefined ceil() reference when building msgl-fsearch.c

[gnu4u]

Hello!

Some month ago there was a message on this mailing list with the title  
'Re: Upgrade to gettext-0.16.1 gives ceil undefined reference' (10.  
Feb. 2007) .  There were no replies to this.  Today I got the same  
error message and had a closer look.

Description

When compiling gettext-0.16.1 make stops with:
msgl-fsearch.c:589: undefined reference to `ceil'
collect2: ld returned 1 exit status

As stated in the other mail, the symbol MSGMERGE_LIBM is not set.  The  
reason for this is, that the test is somewhat 'special': the program  
that is used to look if -lm must be used or not is:

#include <math.h>
int
main ()
{
static double x; x = ceil(x); x = sqrt(x);
  ;
  return 0;
}

When compiling this with
 gcc -o conftest -g -O2 conftest.c
it results in no error on my system (Linux i686, gcc 4.1.2, binutils  
2.17) because there are inline functions for ceil() and sqrt() and  
they are used.  So there is really no need for '-lm' in this case.
[When using: -fno-inline the complilation fails.]


What I do not understand is, that also the msgl-fsearch.c is build  
with -O2 but it seems that in this case the compiler does *NOT* inline  
the ceil().

Also I have no real patch for this.  For GCC it might be ok when using  
-fno-inline - but for other compilers? (And also I'm not sure if other  
compilers are supported.).  Maybe a better test is to use 'nm' on the  
libm.* and have a look if the 'ceil' symbol is defined there? (Which  
also heavily depends on (the output) of the used nm.)

Kind regards

Andreas Florath