Using automake to change gcc build

Using automake to change gcc build

[Amittai Aviram]

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!

Amittai

Amittai Aviram
PhD Student in Computer Science
Yale University
646 483 2639
amittai.aviram@yale.edu
http://www.amittai.com

Re: 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.

Re: Using automake to change gcc build

[Ian Lance Taylor]

Amittai Aviram <amittai.aviram@yale.edu> writes:

> It seems to me that a version 2.65 autoconf should be sufficiently
> backward compatible to deal with input for the previous minor version.

Yes, that would indeed be nice.

Ian

Re: Using automake to change gcc build

[Ralf Wildenhues]

Hello Amittai,

* Amittai Aviram wrote on Tue, Jan 11, 2011 at 08:17:39AM CET:
> 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.  
[...]

> Then I ran automake in order to produce (I thought) the corresponding
> Makefile.in, and got this error:
> 
> $ automake
[...]
> 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
[...]

> 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?

The GCC tree requires an exact version, rather than a minimal version of
Autoconf, because the generated files are committed into version control
and there would be spurious differences due to version skew all the time
otherwise; this used to be the case before the check was put into place.

However, the config/override.m4 macro file also documents how this check
can be overridden (at the location given in the error message): by
m4_define'ing _GCC_AUTOCONF_VERSION to the version you use early.  Thus,
you could either patch override.m4 right away and enter your version
there, or do that in the configure.ac file (before AC_INIT) which
belongs to the part of the GCC tree you are working on.

Hope that helps.

Cheers,
Ralf