CMake execute_process on Windows with paths having spaces

execute_process_win32.cmake

# Toy example--execute_process() on Windows is challenging to handle paths with spaces
# Non-Winows sh -c just works.

set(setvars "set CC=gcc")
set(cmd "cc main.c")

set(cmd $ENV{COMSPEC} /c "${setvars} && ${cmd}")

string(REPLACE "C:/Program Files/" "C:/Progra~1/" cmd "$cmd}")
string(REPLACE "C:/Program Files (x86)/" "C:/Progra~2/" cmd "${cmd}")

execute_process(COMMAND ${cmd})