This directory contains extensions and other support for GNU autoconf.


They are organized by category, so that you can include subsets in your own
aclocal.m4 files if you prefer (the aclocal.m4 file here includes them
all).

File Manifest
-------------
Makefile.in       - Makefile to build documentation on these macros;
                    requires doctext
README            - This file
acconfig.h.in     - Needed to make autoheader read the other acconfig files
acconfig_cc.h     - Define names needed by autoheader for aclocal_cc.m4
acconfig_f77.h    - Define names needed by autoheader for aclocal_f77.m4
acconfig_mpi.h    - Define names needed by autoheader for aclocal_mpi.m4
aclangf90.m4      - Fortran 90 support for autoconf 2.52
aclocal.m4        - Master aclocal file that includes the others
aclocal_am.m4     - Macros for Automake compatibility
aclocal_atomic.m4 - Macros for processor-atomic operations
aclocal_bugfix.m4 - Bug fixes for autoconf macros, including a few extensions
aclocal_cache.m4  - Bug fixes for result caching in autoconf (from 2.13)
aclocal_cc.m4     - Macros for C
aclocal_cross.m4  - Macros for cross-compilation
aclocal_csharp.m4 - Macros for C#
aclocal_cxx.m4    - Macros for C++
aclocal_enable.m4 - Experimental support for AC_ARG_ENABLE.
aclocal_f77.m4    - Macros for Fortran 77
aclocal_f90.m4    - Fortran 90 support for autoconf 2.x for x < 52
aclocal_java.m4   - Macros for Java
aclocal_make.m4   - Macros for Make
aclocal_mpi.m4    - Macros for MPI
aclocal_perl.m4   - Macros for PERL
aclocal_shl.m4    - Macros for shared libraries
aclocal_subcfg.m4 - Special support for subdirectory configures in MPICH2
aclocal_util.m4   - Miscellaneous macros
aclocal_web.m4    - Macros for web-based documentation
config.guess      - Autoconf support file (needed to run autoconf)
config.sub        - Autoconf support file (needed to run autoconf)
f90base.m4        - Fortran 90 support for previous autoconf (now obsolete)
fortran90.m4      - Fortran 90 support for autoconf 2.x for x > 52
install-sh        - Autoconf support file (needed to run autoconf)
libtool-2.13.m4   - deleted?
libtool.m4        - deleted?
ltmain-2.13.sh    - deleted?
ltmain.sh         - deleted?
pac.tex           - Master file to create PDF documentation of
                    autoconf macros

History
-------
These were originally developed to add features needed for MPICH
(before MPICH2) to Autoconf 2.12, including better support for Fortran 77
and Fortran 90, better cross-compilation support, and fixes for bugs
(including bugs in result caching that would cause incorrect behavior
when building on multiple systems from the same directory).  As
autoconf evolved (often in ways that were incompatible with previous
versions), the code in these files attempted to remain compatible
across a range of autoconf versions (in particular, there are three
different files for Fortran support, since incompatibilities between
autoconf versions made this the most efficient and reliable way to
provide the Fortran services).  With the autoconf 2.6x series, we
decided to stop providing backward compatibility (note that 2.61 isn't
even compatible with 2.62, so this was a major change in approach).
However, these files have not been edited to remove macros and
commands that are no longer relevant.


