warp: Facebook's C and C++ Preprocessor

warp is an open-source preprocessor for the C and C++ programming languages. We use it at Facebook as a faster replacement of cpp, GNU's preprocessor.

The companion program warpdrive drives warp in conjunction with the predefined macros of a few of today's crop of compilers (gcc 4.7.1, gcc 4.8.1, clang 3.2, and clang 3.4).

Currently warp's build has only been tested with gcc 4.7.1 and gcc 4.8.1 on CentOS 6. More officially supported platforms to follow.

Dependencies

You need a D compiler installation, which can be downloaded from here. For maximum speed we recommend using the gdc compiler.

Building and using warp

warp by itself is agnostic of the C or C++ dialect implemented by a particular compiler. It is common for compilers to implicitly define a number of macros that affect the precompilation process. To help with that, warp is accompanied by warpdrive, a simple driver program that invokes warp with the appropriate #defines for a few popular compilers.

To build warp, use the simple Makefile that's part of the distribution:

make -j

This will produce warp (the core program) and also the drivers warpdrive_gcc4_7_1, warpdrive_gcc4_8_1, warpdrive_clang3_2, warpdrive_clang3_4, and warpdrive_clangdev, each packaged for the respective compiler and version.

To invoke warp, simply use

warpdrive <flags> filename

In all likelihood you'll need to use -I for adding paths to included library files (warpdrive doesn't bake those in.)