The autotools structure of a package

Writing packages which compile on all platforms and can easily be maintained is a complex task. The Mathemagix philosophy is to be as standard and simple as possible, by using the following guidelines:

  1. Systematically use Automake/Autoconf, even though these tools are very bureaucratic.

  2. Keep configure.ac and the Makefile.am as straightforward as possible.

  3. Use a uniform organization for the directory structure.

More precisely, the directory structure of a new package foox should be as follows:

foox
| configure.ac
| Makefile.am
| macros
| | ac_prefix_config_h.m4
| | mmx_module.m4
| | dependency.m4
| | ...
| build
| | Makefile.am
| include
| | foox
| | | header_file1.hpp
| | | ...
| src
| | src_file1.cpp
| | ...
| glue
| | glue_file1.cpp
| | ...
| script
| | foox-config.in
| bin 
| | ...
| test
| | ...
| subdir ...

Of course, there may be multiple dependency: any external dependency of your package should come with a separate .m4 file. Similarly, you also have one subdir for each type of functionality of your package. A configuration file foox/include/foox-config.hpp should be created automatically using autoheader and AC_PREFIX_CONFIG_H. The file foox/Makefile.am is very short and mainly refers to the main makefile foox/build/Makefile.am.

1.The file configure.ac

The file configure.ac should be modeled on the corresponding file of basix. In particular, you have to start with something like

AC_INIT([foox], [0.2.2], [bugs@mathemagix.org])
AC_CONFIG_AUX_DIR(.)
AC_CONFIG_MACRO_DIR([macros])
AM_INIT_AUTOMAKE([nostdinc -Wall -Werror foreign])
AC_CONFIG_HEADER(foox/include/config.hpp)

AC_PROG_CC
AC_PROG_CXX
AC_LANG_CPLUSPLUS
AC_PROG_INSTALL
...

and end with something like

AC_OUTPUT([
  Makefile
  build/Makefile
  script/foox-config
],[chmod +x script/foox-config])

AC_PREFIX_CONFIG_H(FOOX,
  [include/foox/config.hpp],
  [include/foox-config.hpp])

The file mmx_module.m4 defines a convenient macro AC_MMX_MODULE. When calling this macro inside your configure.ac, the following common options for Mathemagix packages will be supported.

–enable-debug

Enable debugging (disabled by default).

–enable-optimize

Enable optimization (enabled by default).

–enable-exceptions

Support exceptions for high level routines (enabled by default).

–enable-verify

Enable security checks for low level routines (disabled by default).

–enable-glue

Build the glue libraries for use with the interpreter (enabled by default).

–enable-test

Build suite of test programs (disabled by default).

–enable-bench

Build suite of benchmark programs (disabled by default).

–enable-doc

Activate the building of the documentation (disabled by default).

Additional dependencies should all come with a corresponding m4 file. For instance, numerix tests for gmp in the following way:

AC_WITH_GMP
AC_LIB_GMP

The macro AC_WITH_GMP provides an option to specify the install path for gmp. The macro AC_LIB_GMP tests whether it is possible to execute some functionality of the library. Notice that the m4 files of some of the Mathemagix packages provide similar macros AC_WITH_BASIX, AC_LIB_BASIX, etc.

2.The file Makefile.am

Each package should come with a global Makefile.am which should be kept as straightforward as possible and the build/Makefile.am, which control how to build the package. Let us describe its content.

First of all, all include files in foox/include/ should be put into the mathemagix subdirectory of includedir:

mmxincludedir = $(includedir)/mathemagix

mmxinclude_HEADERS = \
  ../include/foox/file1.hpp \
  ../include/foox/file2.hpp \
  ../include/foox/file3.hpp \
  ...

One next has to specify the Libtool library libfoox.la

lib_LTLIBRARIES = libfoox.la

and the corresponding sources to be built:

libfoox_la_CPPFLAGS = \
  -I../include \
  ... \
  @CPPFLAGS@

libfoox_la_SOURCES = \
  ../src/foo1.cpp \
  ../src/foo2.cpp \
  ...

We also have to provide a configuration script foox/script/foox-config.in and distribute it with our package:

EXTRA_DIST =  \
  ../macros/ac_prefix_config_h.m4 \ 
  ../macros/mmx_module.m4 \
  ...  \
  ../specif/foox-autotools.mmx

In order to produce a clean distribution of the package, you also have to add:

DISTCLEANFILES = ../include/foox-config.hpp

In addition to the above required sources and targets, additional libraries and binaries may have to be built as a function of the configuration options –enable-glue, –enable-test and –enable-bench. For instance, in order to build the library which has to be glued to the interpreter, one typically adds the following lines:

if GLUE_OPT
  mmxinclude_HEADERS += \
  ../include/foox/file1.hpp \
  ../include/foox/file2.hpp \
  ...    

  lib_LTLIBRARIES += libmmxfoox.la

  libmmxbasix_la_CPPFLAGS = \
    -I../glue \
    ... \
    $(libfoox_la_CPPFLAGS)

  libmmxfoox_la_SOURCES = \
    ../glue/glue1.cpp \
    ../glue/glue2.cpp \
    ...
endif

For the other options, and as a more general rule, we recommend to mimick the code in the existing files */build/Makefile.am.

3.Inclusion in the global Mathemagix project

When your package is finished, according to the above guidelines, then we can include it in the main Mathemagix tree. Prior to this inclusion some modifications are necessary so that the above configuration and installation files could be maintained automatically by the script automagix.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU General Public License. If you don't have this file, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.