Buildsystem/Genrev: Fixed revision generator not reading existing cmake cache variables

cmake/genrev.cmake

@@ -12,21 +12,19 @@
 # This is done EACH compile so they can be alerted about the consequences.
 
 if(NOT BUILDDIR)
-  # Workaround for funny MSVC behaviour - this segment only run during compile
-  set(NO_GIT ${WITHOUT_GIT})
-  set(GIT_EXEC ${GIT_EXECUTABLE})
+  # Workaround for funny MSVC behaviour - this segment is only used when using cmake gui
   set(BUILDDIR ${CMAKE_BINARY_DIR})
 endif()
 
-if(NO_GIT)
+if(WITHOUT_GIT)
   set(rev_date "1970-01-01 00:00:00 +0000")
   set(rev_hash "unknown")
   set(rev_branch "Archived")
 else()
-  if(GIT_EXEC)
+  if(GIT_EXECUTABLE)
     # Create a revision-string that we can use
     execute_process(
-      COMMAND "${GIT_EXEC}" describe --match init --dirty=+ --abbrev=12
+      COMMAND "${GIT_EXECUTABLE}" describe --match init --dirty=+ --abbrev=12
       WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}"
       OUTPUT_VARIABLE rev_info
       OUTPUT_STRIP_TRAILING_WHITESPACE
@@ -35,7 +33,7 @@ else()
 
     # And grab the commits timestamp
     execute_process(
-      COMMAND "${GIT_EXEC}" show -s --format=%ci
+      COMMAND "${GIT_EXECUTABLE}" show -s --format=%ci
       WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}"
       OUTPUT_VARIABLE rev_date
       OUTPUT_STRIP_TRAILING_WHITESPACE
@@ -44,7 +42,7 @@ else()
 
     # Also retrieve branch name
     execute_process(
-      COMMAND "${GIT_EXEC}" rev-parse --abbrev-ref HEAD
+      COMMAND "${GIT_EXECUTABLE}" rev-parse --abbrev-ref HEAD
       WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}"
       OUTPUT_VARIABLE rev_branch
       OUTPUT_STRIP_TRAILING_WHITESPACE
@@ -69,7 +67,7 @@ else()
 endif()
 
 # Create the actual revision.h file from the above params
-if(NOT "${rev_hash_cached}" MATCHES "${rev_hash}" OR NOT "${rev_branch_cached}" MATCHES "${rev_branch}")
+if(NOT "${rev_hash_cached}" MATCHES "${rev_hash}" OR NOT "${rev_branch_cached}" MATCHES "${rev_branch}" OR NOT EXISTS "${BUILDDIR}/revision.h")
   configure_file(
     "${CMAKE_SOURCE_DIR}/revision.h.in.cmake"
     "${BUILDDIR}/revision.h"