Re: build failure, GMP not available

[Matt Fago <fago at earthlink dot net>]

>From: "Kaveh R. GHAZI" <ghazi@caip.rutgers.edu>
>> Matt Fago wrote:
>> One issue here is that '--with-mpfr=path' assumes that 'libmpfr.a' is
>> in 'path/lib' (not true for how I installed it), while '--with-mpfr-
>> dir=path' assumes that 'libmpfr.a' is in 'path', rather than
>> 'path/.libs' (can this work for anyone?). Note that '--with-gmp-
>> dir=path' does look in 'path/.libs'.
>
>This problem appears in the 4.0 series all the way through current
>mainline.  I do believe it should be fixed and it is simple to do so. I'll
>take care of it.
>
>> My comments:
>>
>> 1) It would have been very useful to have explicit configure options
>> such as --with-gmp-lib=path and --with-gmp-include=path (etc) that
>> explicitly locate the *.a and *.h directories, rather than (or in
>> addition to) the existing "install directory" and "build directory"
>> options.
>
>Yes, the configure included in mpfr itself has this for searching for GMP
>which it relies on.  I'll add something for this in GCC also.

Thank you.

>> 2) Ideally IMHO the top-level configure (or at least the libgfortran
>> configure) would test the execution of some or all of the required
>> functions in GMP/MPFR. I vaguely recall that this is possible with
>> autoconf, and should be more robust. Would it add too much complexity
>> to the top-level configure?
>
>I tend to be reluctant about run tests because they don't work with a
>cross-compiler.  Would you please tell me specifically what problem
>checking at runtime would prevent that the existing compile test doesn't
>detect?

Yes, a cross-compiler could not do runtime tests.  I was trying to think of a 
more robust configuration-time test. This is difficult as I do not quite 
understand why configure was successful in finding the libraries with the
correct versions, but yet the compilation itself failed.  Would a link test 
against all of the required GMP/MPFR functions  (via AC_CHECK_LIB etc)
offer anything?

 Thanks,
 - Matt