[CMake] MSBuild and automatic project file regenation

[Bill Hoffman]

I took a look at this, and it is behaving as expected with VS.  VS does 
NOT have a depend on compile flags.  You can change a .vcproj file and 
the flags it uses all you want, and VS will NOT rebuild any files 
because of that.

So, as far as VS is concerned your source file has not changed and does 
not need to rebuild.  I modified your example and --build works 
perfectly (I change the NUMBER in the CMakeLists.txt and main is rebuilt 
with one invocation of cmake --build .)



CMAKE_MINIMUM_REQUIRED(VERSION 2.8 FATAL_ERROR)
PROJECT(BUILD C)
FILE(WRITE ${CMAKE_BINARY_DIR}/main.c "#include <stdio.h>
#include <main.h>
int main(void)
{
   printf(\"%d\\n\",NUMBER);
   return 0;
}
")
include_directories(${CMAKE_BINARY_DIR})
ADD_EXECUTABLE(main main.c)
set(NUMBER 2)
configure_file(main.h.in main.h)


$ cat ../main.h.in
#define NUMBER @NUMBER@