#config.m4

[agl-tech-ramblings]

Adding make directives for php extensions via config.m4

There are a set of autoconf directives that phpize provides aren’t documented (or don’t appear to be here).

One of these nice directives is PHP_ADD_MAKEFILE_FRAGMENT. When invoked with no parameters, PHP_ADD_MAKEFILE_FRAGMENT will look for Makefile.frag in the current working directory and include the contents into the generated Makefile. When invoked with a filepath, PHP_ADD_MAKEFILE_FRAGMENT will attempt to include the contents of the specified file at the filepath instead of just looking for Makefile.frag.

Specifying Makefile directives opens the door to adding compiler flags for specific build types, additional cleanup directives for testing artifacts, really whatever you want. I use it to specify debug builds.

debug: COMMON_FLAGS += -DDEBUG debug: all

In my code, I can now look for DEBUG in the preprocessor to enable or disable logging, for example. Neato.

[agl-tech-ramblings]

Modifying your PHP Extension’s config.m4 file to enable C++ compilation

I thought this would be harder than it turned out to be.

If you want to enable compilation of c++ files (denoted with a .cpp extension), you need the following stanza:

PHP_REQUIRE_CXX()

You can set c++ compiler flags with the following stanza in your config.m4:

CXXFLAGS='-Wall -std=c++11'

Then you can add your .cpp files to the filelist in PHP_NEW_EXTENSION (2nd parameter). Running phpize && ./configure should generate a new Makefile with your .cpp files compiling via your C++ compiler!

Keep in mind that these will be joined with any C flags set via the PHP_NEW_EXTENSION function call (in the 5th parameter I believe), so you may want to set C compiler flags explicitly with:

CFLAGS=`-Wall -std=c99`