[CMake] Problem with override file ...

[Michael Burns]

Using the following override file results in the try_compile failing for
both the C compiler and the C++ compiler. The output shows that the
override file is being processed multiple times. The first time it is
processed, the variable PARAM is 'set' as specified on the CMake command
line. However, subsequent processing of the file shows that PARAM is not
'set' and results in the 'bogus-option' being added to the compiler
command line. This, of course, results in the try_compile's failing.

message(STATUS "Processing override_compiler_flags.cmake ...")

if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_GNUCXX)
    if(PARAM STREQUAL "set")
        message(AUTHOR_WARNING "PARAM is 'set' ...")
        add_definitions("-DPARAM=1")
    else()
        message(AUTHOR_WARNING "PARAM is not 'set' ...")
        add_definitions("--bogus-option")
    endif()
endif()

The CMake process is initiated with the following command line.

$ cmake -DPARAM=set ..

And, usage of the override file is set with the following before the
project is defined.

set(CMAKE_USER_MAKE_RULES_OVERRIDE
${CMAKE_CURRENT_SOURCE_DIR}/override_compiler_flags.cmake)

I have attached the output of the CMake run as well.

Is this a bug in that subsequent processing of the override file is not
using the cached value of PARAM?
Or, is there something wrong with the override file itself?

Thanks!

Mike

-------------- next part --------------
$ cmake -DPARAM=set ..
-- The C compiler identification is GNU 4.7.3
-- The CXX compiler identification is GNU 4.7.3
-- Processing override_compiler_flags.cmake ...
CMake Warning (dev) at override_compiler_flags.cmake:5 (message):
  PARAM is 'set' ...
Call Stack (most recent call first):
  /usr/local/share/cmake-3.6/Modules/CMakeCInformation.cmake:94 (include)
  CMakeLists.txt:7 (project)
This warning is for project developers.  Use -Wno-dev to suppress it.

-- Check for working C compiler: /usr/bin/cc
CMake Warning (dev) at /cmake-test/override_compiler_flags.cmake:8 (message):
  PARAM is not 'set' ...
Call Stack (most recent call first):
  /usr/local/share/cmake-3.6/Modules/CMakeCInformation.cmake:94 (include)
  /cmake-test/test/CMakeFiles/CMakeTmp/CMakeLists.txt:3 (project)
This warning is for project developers.  Use -Wno-dev to suppress it.

-- Check for working C compiler: /usr/bin/cc -- broken
CMake Error at /usr/local/share/cmake-3.6/Modules/CMakeTestCCompiler.cmake:61 (message):
  The C compiler "/usr/bin/cc" is not able to compile a simple test program.

  It fails with the following output:

   Change Dir: /cmake-test/test/CMakeFiles/CMakeTmp

  

  Run Build Command:"/usr/bin/make" "cmTC_68ea8/fast"

  /usr/bin/make -f CMakeFiles/cmTC_68ea8.dir/build.make
  CMakeFiles/cmTC_68ea8.dir/build

  make[1]: Entering directory `/cmake-test/test/CMakeFiles/CMakeTmp'

  Building C object CMakeFiles/cmTC_68ea8.dir/testCCompiler.c.o

  /usr/bin/cc --bogus-option -o CMakeFiles/cmTC_68ea8.dir/testCCompiler.c.o
  -c /cmake-test/test/CMakeFiles/CMakeTmp/testCCompiler.c

  cc: error: unrecognized command line option ‘--bogus-option’

  make[1]: *** [CMakeFiles/cmTC_68ea8.dir/testCCompiler.c.o] Error 1

  make[1]: Leaving directory `/cmake-test/test/CMakeFiles/CMakeTmp'

  make: *** [cmTC_68ea8/fast] Error 2

  

  

  CMake will not be able to correctly generate this project.
Call Stack (most recent call first):
  CMakeLists.txt:7 (project)


-- Configuring incomplete, errors occurred!
See also "/cmake-test/test/CMakeFiles/CMakeOutput.log".
See also "/cmake-test/test/CMakeFiles/CMakeError.log".