Re: gcc trunk and -lmpc

[Ian Lance Taylor <iant@google.com>]

Alexey Salmin <alexey.salmin@gmail.com> writes:

> Hello! Today I tried to build latest gcc trunk (rev #158628) and got
> the following errors:
>
> libbackend.a(builtins.o): In function `fold_builtin_ccos':
> /home/salmin/gcc-trunk/host-x86_64-unknown-linux-gnu/gcc/../.././gcc/builtins.c:7341:
> undefined reference to `mpc_cosh'
> /home/salmin/gcc-trunk/host-x86_64-unknown-linux-gnu/gcc/../.././gcc/builtins.c:7341:
> undefined reference to `mpc_cos'
> libbackend.a(builtins.o): In function `fold_builtin_cexp':
> /home/salmin/gcc-trunk/host-x86_64-unknown-linux-gnu/gcc/../.././gcc/builtins.c:7434:
> undefined reference to `mpc_exp'
> ....
>
> which is surprising because I have libmpc installed (debian sid):
> salmin@salmin:~/gcc-trunk$ dpkg -l libmpc* | grep ^ii | grep -v libmpcdec
> ii  libmpc-dev                           0.8.1-1
>          multiple precision complex floating-point library development
> package
> ii  libmpc2                              0.8.1-1
>          multiple precision complex floating-point library
>
> configuring with LDFLAGS=-lmpc solved the problem. Is it a bug in
> Makefile or something or I'm doing it wrong?

This certainly sounds like a bug in the configure script or the
Makefile.  It may be that since mpc is so new few people have tested
building gcc against an installed libmpc.

Ian