office-gobmx/config/README
Luboš Luňák 1aad4689ba use config_xxx.h files instead of -DHAVE_XXX on the command line
As the latter does not quite scale, and also source files depending
on the setting/feature did not rebuild in case of a change.

There are intentionally more config_xxx.h files (so autoheader
from autotools is not used), so that a setting change does not force
automatically a rebuild of everything. Running configure does not
touch those config_xxx.h files that have not changed.

There's config/README with a howto.

Change-Id: I6d6e82050ff8faf5364ed246848b8401aca3e0e5
2012-12-07 19:48:16 +01:00

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These are configuration files for various features as detected by configure.
Include only those files you need (in order to reduce rebuilds when a setting changes).
Settings here are only C/C++ #define directives, so they apply only to C/C++ source,
not to Makefiles.
Adding a new setting:
=====================
- do AC_DEFINE(HAVE_FOO) in configure.ac when a setting should be set
- choose the proper config/config_xxx.h file to use
- if it is a global setting (such as availability of a compiler feature),
use config/config_global.h
- otherwise check if there is a matching config/config_hxx.h file
- if none matches, add a new one:
- add config/config_xxx.h.in here, with just #ifndef include guard
- add AC_CONFIG_HEADERS([config/config_xxx.h]) next to the others
in configure.ac
- add config_hxx.h to config/.gitignore
- add #undef HAVE_FOO to the config/config_hxx.h , possibly with a comment
- add #include <config_xxx.h> before any #ifdef HAVE_XXX in a source file