[CMake] makefile to CMakeLists.txt, possible?

[Alexander Neundorf]

On Thursday 02 September 2010, Raymond Wan wrote:
> Hi Chiheng,
>
> On Thu, Sep 2, 2010 at 16:15, Chiheng Xu <chiheng.xu at gmail.com> wrote:
> > CMake is a very great tool.    But its drawback is also obvious.    It
> > will consume large amount of time to generate Makefiles every time you
> > want to build,  especially for ultra large projects.   Building can be
> > parallelized, but the CMaking, like runing configure scripts, can't be
> > parallelized.   So, the "caching" of Makefiles seems benefitial  for
> > current and future mutil-cores systems.
> >
> > Normal developers seldomly touch CMakeLists.txt.  So,  in very rare
> > condition, you need to regenerate the Makefiles.
>
> As someone who just started using CMake (quite literally a few weeks
> ago), I'm somewhat interested in your arguments.  Personally, I don't
> see many drawbacks and I must be missing something if they are
> "obvious".

Generated makefiles can't be portable e.g. because they contain include paths 
and paths to libraries which will be linked which can differ on each system.
Also, the generated makefiles contain calls to cmake e.g. for the progress 
report.
Also, it is quite common to use cmake -E for cross platform commands e.g. in 
add_custom_command() or add_custom_target(), which results in rules in the 
makefiles which call cmake to do something,  e.-g. copy a file or something.

> It is true that while developing software, using CMake requires an
> extra step.  For example, when you add a C++ source file, you'll need
> to run cmake and then make. 

If cmake has already generated makefiles for you, you don't need to invoke it 
manually again after editing CMakeLists.txt, the generated makefiles include 
this dependency and rerun cmake automatically for you.


Nevertheless, some way to make something in cmake parallel would be nice :-)
But at least for me it's not obvious how to do that.

Alex