Profiler runs with gperftools showed we were spending
a lot of time in strlen() even with compiled match patterns.
If you compare a std::string with a plain C-string,
the comparison operator needs to calculate the length
of the C-string via strlen().
We can avoid this by turning all C-strings into C++ strings,
which cache the string length internally.
The match compiler has been adapted to collect all
C-strings during compilation and aggregate them.
Benchmark on the 'rpm' code base on a Core i7 920 box:
cppcheck without matchcompiler:
real 0m30.977s
cppcheck with previous matchcompiler:
real 0m28.157s
cppcheck with cached C-strings:
real 0m17.823s
Thomas Jarosch
Daniel Marjamäki