Generate a cairo-perf-diff graph for a series of commits in order to be
able to identify significant commits. Still very crude, but minimally
functional.
Quick summary of changes:
- Move list of cairo source files out of src/Makefile.am and into
src/Sources.mk,
- Generate files src/Config.mk and src/Config.mk.win32 that choose
the right set of source files and headers based on configured
backends and features. This drastically simplifies building
using other build systems. The src/Makefile.win32 file needs
to be updated to reflect these changes.
- Add README files to various directories,
- Add toplevel HACKING file.
The old cairo-perf-diff is now named cairo-perf-diff-files, but
the new one calls out to it and can still be used in an identical
way.
The new cairo-perf-diff can also be used to see what the performance
impact of a single commit is like so:
cairo-perf-diff HEAD
or between two commits:
cairo-perf-diff 1.2.4 HEAD
The script is careful to always run the latest cairo-perf program
even when testing old versions of the library. Also, the output
from any given performance run is cached so it gets less painful
to run as the cache gets primed (the cache is in .perf next to
.git).
The script is still a bit fragile in spots. In particular it depends
on cairo-perf being built in advance but doesn't do anythin to ensure
that happens.
