Using automake to change gcc build

[Jonathan Wakely]

On 11 January 2011 07:17, Amittai Aviram wrote:
> I want to add a few files to the gcc source tree and build and test the resulting gcc, but I am having trouble finding my way around the Automake system.
>
> For example, one of the files I want to add is a local (altered) version of malloc.c.  So I added "malloc.c" here:
>
> libgomp_la_SOURCES = alloc.c barrier.c critical.c env.c error.c iter.c \
>        iter_ull.c loop.c loop_ull.c malloc.c ordered.c parallel.c sections.c \
>        single.c task.c team.c work.c lock.c mutex.c proc.c sem.c bar.c \
>        ptrlock.c time.c fortran.c affinity.c
>
> Then I ran automake in order to produce (I thought) the corresponding Makefile.in, and got this error:
>
> $ automake
> aclocal.m4:16: warning: this file was generated for autoconf 2.64.
> You have another version of autoconf.  It may work, but is not guaranteed to.
> If you have problems, you may need to regenerate the build system entirely.
> To do so, use the procedure documented by the package, typically `autoreconf'.
> configure.ac:5: error: Please use exactly Autoconf 2.64 instead of 2.65.
> ../config/override.m4:34: _GCC_AUTOCONF_VERSION_CHECK is expanded from...
> configure.ac:5: the top level
> autom4te: /usr/bin/m4 failed with exit status: 1
> automake: autoconf failed with exit status: 1
>
> Now, if query the version of autoconf on my system, here is what I get:
>
> $ autoconf --version
> autoconf (GNU Autoconf) 2.65
>
> It seems to me that a version 2.65 autoconf should be sufficiently backward compatible to deal with input for the previous minor version.  So why am I running into this problem and what can I do about it?  Thank you!

As the message says:
configure.ac:5: error: Please use exactly Autoconf 2.64 instead of 2.65.

You need to install autoconf 2.64 somewhere (e.g. under your home dir)
and make sure it is first in your $PATH.