1# PHP build system V5 overview 2 3* supports Makefile.ins during transition phase 4* not-really-portable Makefile includes have been eliminated 5* supports separate build directories without VPATH by using explicit rules only 6* does not waste disk-space/CPU-time for building temporary libraries => 7 especially noticeable on slower systems 8* slow recursive make replaced with one global Makefile 9* eases integration of proper dependencies 10* abandoning the "one library per directory" concept 11* improved integration of the CLI 12* several new targets: 13 * `build-modules`: builds and copies dynamic modules into `modules/` 14 * `install-cli`: installs the CLI only, so that the install-sapi target does 15 only what its name says 16* finally abandoned automake 17* changed some configure-time constructs to run at buildconf-time 18* upgraded shtool to 1.5.4 19* removed `$(moduledir)` (use `EXTENSION_DIR`) 20 21## The reason for a new system 22 23It became more and more apparent that there is a severe need for addressing the 24portability concerns and improving the chance that your build is correct (how 25often have you been told to `make clean`? When this is done, you won't need to 26anymore). 27 28## If you build PHP on a Unix system 29 30You, as a user of PHP, will notice no changes. Of course, the build system will 31be faster, look better and work smarter. 32 33## If you are developing PHP 34 35### Extension developers 36 37Makefile.ins are abandoned. The files which are to be compiled are specified in 38the `config.m4` now using the following macro: 39 40```m4 41PHP_NEW_EXTENSION([foo], [foo.c bar.c baz.cpp], [$ext_shared]) 42``` 43 44E.g. this enables the extension foo which consists of three source-code modules, 45two in C and one in C++. And, depending on the user's wishes, the extension will 46even be built as a dynamic module. 47 48The full syntax: 49 50```m4 51PHP_NEW_EXTENSION(extname, sources [, shared [,sapi_class[, extra-cflags]]]) 52``` 53 54Please have a look at `build/php.m4` for the gory details and meanings of the 55other parameters. 56 57And that's basically it for the extension side. 58 59If you previously built sub-libraries for this module, add the source-code files 60here as well. If you need to specify separate include directories, do it this 61way: 62 63```m4 64PHP_NEW_EXTENSION([foo], [foo.c mylib/bar.c mylib/gregor.c],,, [-I@ext_srcdir@/lib]) 65``` 66 67E.g. this builds the three files which are located relative to the extension 68source directory and compiles all three files with the special include directive 69(`@ext_srcdir@` is automatically replaced). 70 71Now, you need to tell the build system that you want to build files in a 72directory called `$ext_builddir/lib`: 73 74```m4 75PHP_ADD_BUILD_DIR([$ext_builddir/lib]) 76``` 77 78Make sure to call this after `PHP_NEW_EXTENSION`, because `$ext_builddir` is 79only set by the latter. 80 81If you have a complex extension, you might to need add special Make rules. You 82can do this by calling `PHP_ADD_MAKEFILE_FRAGMENT` in your `config.m4` after 83`PHP_NEW_EXTENSION`. 84 85This will read a file in the source-dir of your extension called 86`Makefile.frag`. In this file, `$(builddir)` and `$(srcdir)` will be replaced by 87the values which are correct for your extension and which are again determined 88by the `PHP_NEW_EXTENSION` macro. 89 90Make sure to prefix *all* relative paths correctly with either `$(builddir)` or 91`$(srcdir)`. Because the build system does not change the working directory 92anymore, we must use either absolute paths or relative ones to the top 93build-directory. Correct prefixing ensures that. 94 95## General info 96 97The foundation for the new system is the flexible handling of sources and their 98contexts. With the help of macros you can define special flags for each 99source-file, where it is located, in which target context it can work, etc. 100 101Have a look at the well documented macros `PHP_ADD_SOURCES(_X)` in 102`build/php.m4`. 103
