[CMake] Python test scripts

[Michael Hertling]

On 10/24/2010 01:26 AM, Bill Spotz wrote:
> Hi,
> 
> Is there a standard way to make tests for python extension modules?
> 
> Currently, I copy test scripts from the source directory to the binary directory.  I would like to augment this by making the first line of my script
> 
>   #! ${PYTHON_EXECUTABLE}
> 
> but the only copy facility I see that supports this substitution is
> 
>   CONFIGURE_FILE(...)
> 
> The problem with this is that the file gets copied over during configuration, and it would be much preferable to have it copied during the build phase.  Is there a copy facility that performs substitutions that executes during the build phase?

You might use a CMake script which is executed at build time:

CMAKE_MINIMUM_REQUIRED(VERSION 2.8 FATAL_ERROR)
PROJECT(PYTHONTEST C)
SET(PYTHON_EXECUTABLE "path/to/python")
FILE(WRITE ${CMAKE_BINARY_DIR}/pythontest.py.in "#! @INTERPRETER@\n")
FILE(WRITE ${CMAKE_BINARY_DIR}/pythontest.cmake "
CONFIGURE_FILE(${CMAKE_BINARY_DIR}/pythontest.py.in
               ${CMAKE_BINARY_DIR}/pythontest.py)\n")
ADD_CUSTOM_COMMAND(OUTPUT ${CMAKE_BINARY_DIR}/pythontest.py
    COMMAND ${CMAKE_COMMAND} -D INTERPRETER=${PYTHON_EXECUTABLE}
                             -P pythontest.cmake
    DEPENDS ${CMAKE_BINARY_DIR}/pythontest.py.in)
FILE(WRITE ${CMAKE_BINARY_DIR}/main.c "int main(void){return 0;}\n")
ADD_EXECUTABLE(main main.c pythontest.py)

So, CONFIGURE_FILE() is delayed until the custom command's invocation.
Anyway, the variables' values that are subject to substitution, i.e.
INTERPRETER in the example, must be provided at configuration time.

Regards,

Michael