[cmake-developers] [CMake] CMake 2.8.12.201401116 is much slower than 2.8.12.1

[Ben Boeckel]

On Thu, Jan 16, 2014 at 08:41:58 -0700, Clinton Stimpson wrote:
> I'm surprised how this small change added a 20% slowdown.
> -set_property(DIRECTORY APPEND PROPERTY COMPILE_DEFINITIONS_DEBUG QT_DEBUG)
> +set_property(DIRECTORY APPEND PROPERTY COMPILE_DEFINITIONS $<$<NOT:
> $<CONFIG:Debug>>:QT_NO_DEBUG>)

There's a lot of places where std::string gets passed as a const char*
only to be turned back into a std::string in the function. Would it be
worth me trying to resurrect that branch again? It wasn't worth much
last I tried, but that was before a lot of the generator expression
stuff was added.

I guess another question is whether the genex is evaluated once or
per-target (I'd guess the latter which might be the reason especially if
Qt4 is found at the top-level of a larger project).

--Ben