Bundled Extensions

Bundled extensions are maintained in ext/ as part of php-src.

Extension Developers

The files which are to be compiled are specified in config.m4 using the following macro:

PHP_REQUIRE_CXX()
PHP_NEW_EXTENSION([foo], [foo.c bar.c baz.cpp], [$ext_shared],,, [cxx])

E.g. this enables the extension foo which consists of three source-code modules, two in C and one in C++. And, depending on the user’s wishes, the extension will even be built as a dynamic module. PHP_REQUIRE_CXX initialises the C++ toolchain, and the cxx argument makes a shared extension use the C++ linker.

The full syntax:

PHP_NEW_EXTENSION(extname, sources [, shared [, sapi_class [, extra-cflags [, cxx [, zend_ext]]]]])

Please have a look at build/php.m4 for the gory details and meanings of the other parameters.

And that’s basically it for the extension side.

If you would otherwise build sub-libraries for this module, add the source-code files here as well. If you need to specify separate include directories, do it this way:

PHP_NEW_EXTENSION([foo], [foo.c mylib/bar.c mylib/gregor.c],,, [-I@ext_srcdir@/lib])

E.g. this builds the three files which are located relative to the extension source directory and compiles all three files with the special include directive (@ext_srcdir@ is automatically replaced).

Now, you need to tell the build system that you want to build files in a directory called $ext_builddir/lib:

PHP_ADD_BUILD_DIR([$ext_builddir/lib])

Make sure to call this after PHP_NEW_EXTENSION, because $ext_builddir is only set by the latter.

If you have a complex extension, you might need to add special Make rules. You can do this by calling PHP_ADD_MAKEFILE_FRAGMENT in your config.m4 after PHP_NEW_EXTENSION.

This will read a file in the source-dir of your extension called Makefile.frag. In this file, $(builddir) and $(srcdir) will be replaced by the values which are correct for your extension and which are again determined by the PHP_NEW_EXTENSION macro.

Make sure to prefix all relative paths correctly with either $(builddir) or $(srcdir). Because the build system does not change the working directory anymore, we must use either absolute paths or relative ones to the top build-directory. Correct prefixing ensures that.

General Info

The foundation for the build system is the flexible handling of sources and their contexts. With the help of macros you can define special flags for each source-file, where it is located, in which target context it can work, etc.

Have a look at the well documented PHP_ADD_SOURCES macro in build/php.m4.