1. dirkbaechle
  2. SCons_fastcpp


fastcpp Tool for SCons

This Tool is specialized on speeding up large C/CPP builds, measured in terms of source files.

!!Disclaimer!!: For achieving significant speedups, this Tool uses several shortcuts that might lead to insecure builds. It may work and your builds get faster, but it might also give you more trouble than you've asked for. If in doubt, disable the Tool immediately and get back to relying on SCons' default behaviour for analyzing signatures and implicit dependencies.

You have been warned!

In particular, what this Tool does is:

  1. It installs a very simplified C/CPP scanner, which might not find all dependencies based on file includes.
  2. Switches off implicit dependencies for commands like g++ and ar, such that your build will not automatically detect when you install a new C++ compiler for example. The same holds for executables that you create during your build, and then generate further source files with it.
  3. Pre-expands several prefixes and suffixes for things like object file and libraries. This might be a problem if your build description relies on construction variables like $OBJPREFIX.


With the provided SConstruct, you can install the Tool to your local SCons configuration folder by calling:

scons install


You activate the Tool by adding it to the tools= list as follows:

env = Environment(tools=['default','fastcpp'])

. The default set of tracked C/CPP suffixes is:

'.c', '.cpp', '.h'

and they can be changed by setting the variable FAST_CPPSUFFIXES:

env = Environment(FAST_CPPSUFFIXES=['.hpp', '.C'],