[cmake] Fix add_version_info_from_vcs git svn version bug.

[gberry]

Summary

add_version_info_from_vcs was setting SVN_REVISION to the last fetched
svn revision when using git svn instead of the svn revision
corresponding to HEAD. This leads to conflicts with the definition of
SVN_REVISION in SVNVersion.inc generated by GetSVN.cmake when HEAD is
not the most recently fetched svn revision.

Use 'git svn info' to determine SVN_REVISION when git svn is being used
instead (as is done in GetSVN.cmake).

[jroelofs]

cmake/modules/VersionFromVCS.cmake

76

dead if

[gberry]

Remove empty if.

[beanz]

LGTM.

cmake/modules/VersionFromVCS.cmake

if( EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/.svn" )
     endif()
   elseif( EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/.git )
     set(result "${result}git")
     # Try to get a ref-id
     if( EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/.git/svn )
       find_program(git_executable NAMES git git.exe git.cmd)
       if( git_executable )
         set(is_git_svn_rev_exact false)
-        execute_process(COMMAND ${git_executable} svn log --limit=1 --oneline
+        execute_process(COMMAND
+          ${git_executable} svn info
           WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
           TIMEOUT 5
           RESULT_VARIABLE git_result
           OUTPUT_VARIABLE git_output)
         if( git_result EQUAL 0 )
-          string(REGEX MATCH r[0-9]+ git_svn_rev ${git_output})
-          string(LENGTH "${git_svn_rev}" rev_length)
-          math(EXPR rev_length "${rev_length}-1")
-          string(SUBSTRING "${git_svn_rev}" 1 ${rev_length} git_svn_rev_number)
+          string(REGEX MATCH "URL: ([^ \n]*)" svn_url ${git_output})
+          if(svn_url)
+            set(LLVM_REPOSITORY ${CMAKE_MATCH_1} PARENT_SCOPE)
+          endif()
+
+          string(REGEX REPLACE "^(.*\n)?Revision: ([^\n]+).*"
+            "\\2" git_svn_rev_number "${git_output}")
           set(SVN_REVISION ${git_svn_rev_number} PARENT_SCOPE)
           set(git_svn_rev "-svn-${git_svn_rev}")
 
           # Determine if the HEAD points directly at a subversion revision.
           execute_process(COMMAND ${git_executable} svn find-rev HEAD
             WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
             TIMEOUT 5
             RESULT_VARIABLE git_result
if( EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/.git/svn )
         if( git_result EQUAL 0 AND NOT is_git_svn_rev_exact )
           string(STRIP "${git_output}" git_ref_id)
           set(GIT_COMMIT ${git_ref_id} PARENT_SCOPE)
           set(result "${result}${git_svn_rev}-${git_ref_id}")
         else()
           set(result "${result}${git_svn_rev}")
         endif()
 
-        execute_process(COMMAND
-          ${git_executable} svn info
-          WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
-          TIMEOUT 5
-          RESULT_VARIABLE git_result
-          OUTPUT_VARIABLE git_output)
         if( git_result EQUAL 0)
-          string(REGEX MATCH "URL: ([^ \n]*)" svn_url ${git_output})
-          if(svn_url)
-            set(LLVM_REPOSITORY ${CMAKE_MATCH_1} PARENT_SCOPE)
-          endif()
         endif()
       endif()
     endif()
   endif()
   set(${VERS} ${result} PARENT_SCOPE)
 endfunction(add_version_info_from_vcs)