mpfr.h cannot be located while compiling GCC

[Kai Ruottu]

Ankit Mahanot wrote:

> I added GMP & MPFR folders into GCC source code folder .......
> 
> configured GCC ... into different directory named objdir which is
> outside gcc source code folder.
> 
> Now I am doing make .... but it gives the following error:
> 
> .
> .
> .
> "_mpfr_tan", referenced from:
>       _mpfr_tan$non_lazy_ptr in libbackend.a(builtins.o)
>   "_mpfr_sin", referenced from:
>       _mpfr_sin$non_lazy_ptr in libbackend.a(builtins.o)
> ld: symbol(s) not found
> collect2: ld returned 1 exit status
> make[3]: *** [cc1-dummy] Error 1
> make[2]: *** [all-stage1-gcc] Error 2
> make[1]: *** [stage1-bubble] Error 2
> make: *** [all] Error 2
> 
> I am on MAC OS X 10.5.7. GCC I am trynig to compile is 4.4.1 & GMP i
> am using is gmp-4.2.4 & mpfr-2.4.1

I still suspect you to have some earlier mpfr installed in your
system and its (shared) library being searched instead of the
just built one :(  The mpfr INSTALL says :

------------------------ clip -------------------------------
Under Mac OS X, if the shared library was not installed and you use
Apple's linker (this is the default), you will also need to provide
the -search_paths_first linker flag ("-Wl,-search_paths_first" when
you link via gcc) to make sure that the right library is selected,
as by default, Apple's linker selects a shared library preferably,
even when it is farther in the library paths. We recall that if a
wrong library is selected due to this behavior, unexpected results
may occur.
------------------------ clip -------------------------------

The CFLAGS_FOR_HOST or something could be the right place to
add this "-Wl,-search_paths_first" option. Please search with
Google etc. with this, it seems to be a quite Apple-specific
issue.

The obvious workaround would be to find the existing 'libmpfr*'
library and disable it being found via temporalily renaming it
to '.backup' or something.