[CMake] Building a Version Header

[John Drescher]

On Wed, Jul 7, 2010 at 11:04 PM, John Drescher <drescherjm at gmail.com> wrote:
> On Wed, Jul 7, 2010 at 10:59 PM, Clark Gaebel <cg.wowus.cg at gmail.com> wrote:
>> Is there any way I can use the output from a command-line program (in
>> this case, "git describe --dirty") instead of using FindGit?
>>
>
> I believe
> add_custom_command
>
> but I can not help with an example of that.
>
When looking at the source for FindSubversion.cmake this looks pretty
easy to modify. I guess you can put the Macro code inside your
CMakeLists.txt if you do not want to mess with Findgit.cmake.

MACRO(Subversion_WC_INFO dir prefix)
    # the subversion commands should be executed with the C locale, otherwise
    # the message (which are parsed) may be translated, Alex
    SET(_Subversion_SAVED_LC_ALL "$ENV{LC_ALL}")
    SET(ENV{LC_ALL} C)

    EXECUTE_PROCESS(COMMAND ${Subversion_SVN_EXECUTABLE} --version
      WORKING_DIRECTORY ${dir}
      OUTPUT_VARIABLE Subversion_VERSION_SVN
      OUTPUT_STRIP_TRAILING_WHITESPACE)

    EXECUTE_PROCESS(COMMAND ${Subversion_SVN_EXECUTABLE} info ${dir}
      OUTPUT_VARIABLE ${prefix}_WC_INFO
      ERROR_VARIABLE Subversion_svn_info_error
      RESULT_VARIABLE Subversion_svn_info_result
      OUTPUT_STRIP_TRAILING_WHITESPACE)

    IF(NOT ${Subversion_svn_info_result} EQUAL 0)
      MESSAGE(SEND_ERROR "Command \"${Subversion_SVN_EXECUTABLE} info
${dir}\" failed with output:\n${Subversion_svn_info_error}")
    ELSE(NOT ${Subversion_svn_info_result} EQUAL 0)

      STRING(REGEX REPLACE "^(.*\n)?svn, version ([.0-9]+).*"
        "\\2" Subversion_VERSION_SVN "${Subversion_VERSION_SVN}")
      STRING(REGEX REPLACE "^(.*\n)?URL: ([^\n]+).*"
        "\\2" ${prefix}_WC_URL "${${prefix}_WC_INFO}")
      STRING(REGEX REPLACE "^(.*\n)?Revision: ([^\n]+).*"
        "\\2" ${prefix}_WC_REVISION "${${prefix}_WC_INFO}")
      STRING(REGEX REPLACE "^(.*\n)?Last Changed Author: ([^\n]+).*"
        "\\2" ${prefix}_WC_LAST_CHANGED_AUTHOR "${${prefix}_WC_INFO}")
      STRING(REGEX REPLACE "^(.*\n)?Last Changed Rev: ([^\n]+).*"
        "\\2" ${prefix}_WC_LAST_CHANGED_REV "${${prefix}_WC_INFO}")
      STRING(REGEX REPLACE "^(.*\n)?Last Changed Date: ([^\n]+).*"
        "\\2" ${prefix}_WC_LAST_CHANGED_DATE "${${prefix}_WC_INFO}")

    ENDIF(NOT ${Subversion_svn_info_result} EQUAL 0)

    # restore the previous LC_ALL
    SET(ENV{LC_ALL} ${_Subversion_SAVED_LC_ALL})

  ENDMACRO(Subversion_WC_INFO)


All the work you need is in the EXECUTE_PROCESS. Replace the
subversion commands with git commands and fixup the output.

John