[cmake-developers] slow regex implementation in RegularExpression

[Bill Hoffman]

A little off topic, but I am wondering if the ctest performance issue 
for xcode could be fixed without changing the regex.  The problem with 
xcode is that it spits out very verbose output.  I am wondering if some 
short circuit stuff could be put in place.  Maybe do a string compare of 
the first bit of every line that look for stuff that could not have an 
error in it, and only if it might have an error, do we pass it to the 
regex call.  Basically, if we could reduce the amount of data going into 
the regex stuff, it should work as well as it does for other compilers. 
  The place that this code could go is into cmakexbuild.cxx which 
already strips out all lines that start with setenv.  Maybe even some 
hard coded stuff that looks for errors and only puts those out.  i.e. 
only output lines from cmakexbuild.cxx if there are errors.

-Bill