[CMake] ADD_CUSTOM_COMMAND issues

[Yegor Yefremov]

Brandon Van Every wrote:
> On 7/13/07, Yegor Yefremov <yegor_sub1 at visionsystems.de> wrote:
>> Hello,
>>
>> I want to use ADD_CUSTOM_COMMAND to create tags when building the
>> project. The first problem, ADD_CUSTOM_COMMAND must be placed after the
>> target definition. Should it be so?
>
> Yes.  And it's reasonable, given that you're doing a POST_BUILD command.
>
>> One can parse the CMakeLists.txt and
>> build dependencies so that it doesn't matter where to place
>> ADD_CUSTOM_COMMAND.
>
> Kitware could comment on how difficult it would be to change their
> implementation, but I anticipate the answer would be "very difficult."
>
>> The second issue is that COMMENT won't be printed at all. A didn't use
>> APPEND.
>> [Citation from http://www.cmake.org/HTML/Documentation.html]:
>>
>> The COMMENT, WORKING_DIRECTORY, and MAIN_DEPENDENCY options are
>> currently ignored when APPEND is given, but may be used in the future.
>>
>> But for me it is not the case.
>>
>> Best regards,
>> Yegor Yefremov
>>
>> project (TEST)
>>
>> # some parameters
>> set (CMAKE_VERBOSE_MAKEFILE OFF)
>>
>> # sources
>> set (SRCS test.c)
>>
>> add_custom_command (TARGET test POST_BUILD COMMAND ctags -R 
>> WORKING_DIRECTORY ${HWTEST_SOURCE_DIR} COMMENT "Creating tags" VERBATIM)
>> # executables
>> add_executable (test ${SRCS})
>>
>> #include <stdio.h>
>>
>> int main(int argc, char *argv)
>> {
>>   printf("Hello world\n");
>>
>>   return 1;
>> }
>
> Note to anyone cutting and pasting this code to try it out: first you
> have to put the ADD_EXECUTABLE before the ADD_CUSTOM_COMMAND.  That
> took me a minute to sift through.
>
> I've noted the following weird behavior on the MinGW generator,
> executing under a Windows 2000 command prompt.  I do not have ctags
> installed on my system.  Running from a pristine out-of-source build
> directory, the 1st time I execute "mingw32-make", I get errors as I
> would expect.  The 2nd time, I don't.  Then if I do "mingw32-make
> clean", followed by "mingw32-make", I get errors as I would expect.
> Errors only get reported once per build.
>
> So could this explain why your commands seem to be "not working?"
> What happens when you first execute in a pristine out-of-source build
> directory?
>
> C:\devel\mingw>cd append
>
> C:\devel\mingw\append>mingw32-make
> Scanning dependencies of target test
> [100%] Building C object CMakeFiles/test.dir/test.obj
> Linking C executable test.exe
> process_begin: CreateProcess(NULL, ctags -R, ...) failed.
> make (e=2): The system cannot find the file specified.
> mingw32-make[2]: *** [test.exe] Error 2
> mingw32-make[1]: *** [CMakeFiles/test.dir/all] Error 2
> mingw32-make: *** [all] Error 2
>
> C:\devel\mingw\append>mingw32-make
> [100%] Built target test
>
> C:\devel\mingw\append>mingw32-make clean
>
> C:\devel\mingw\append>mingw32-make
> [100%] Building C object CMakeFiles/test.dir/test.obj
> Linking C executable test.exe
> process_begin: CreateProcess(NULL, ctags -R, ...) failed.
> make (e=2): The system cannot find the file specified.
> mingw32-make[2]: *** [test.exe] Error 2
> mingw32-make[1]: *** [CMakeFiles/test.dir/all] Error 2
> mingw32-make: *** [all] Error 2
>
> C:\devel\mingw\append>
>
>
>
> Cheers,
> Brandon Van Every
> _______________________________________________
> CMake mailing list
> CMake at cmake.org
> http://www.cmake.org/mailman/listinfo/cmake
I'm using Linux and this is my output for the pristine out-of-source build
directory:

user at debianvm:~/projects/temp/cmake_test_build$ cmake ../cmake_test
-- Check for working C compiler: /usr/bin/gcc
-- Check for working C compiler: /usr/bin/gcc -- works
-- Check size of void*
-- Check size of void* - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Configuring done
-- Generating done
-- Build files have been written to:
/home/user/projects/temp/cmake_test_build
user at debianvm:~/projects/temp/cmake_test_build$ make
Scanning dependencies of target test
[100%] Building C object CMakeFiles/test.dir/test.o
Linking C executable test
[100%] Built target test

I have created two directories:
cmake_test
cmake_test_build

The tags file was successfully created in the ${TEST_SOURCE_DIRECTORY}:

user at debianvm:~/projects/temp/cmake_test_build$ ls -l ../cmake_test
total 12
-rw-r--r-- 1 user user 272 2007-07-13 16:23 CMakeLists.txt
-rw-r--r-- 1 user user 383 2007-07-13 16:25 tags
-rw-r--r-- 1 user user  95 2007-07-13 09:09 test.c

Below my corrected CMakeLists.txt:

project (TEST)

# some parameters
set (CMAKE_VERBOSE_MAKEFILE OFF)

# sources
set (SRCS test.c)

# executables
add_executable (test ${SRCS})
add_custom_command (TARGET test POST_BUILD COMMAND ctags -R
WORKING_DIRECTORY ${TEST_SOURCE_DIR} COMMENT "Creating tags" VERBATIM)