From 3024c67995db4d7f2cbe5ac51ce3db5d9e40b872 Mon Sep 17 00:00:00 2001
From: Marco Schulze <marco@ereski.org>
Date: Tue, 30 Dec 2014 18:37:33 -0300
Subject: [PATCH] Regenerate components/version/version.hpp as HEAD moves on a
 git checkout

Pull request #416 introduced a common bug where version.hpp wouldn't be
regenerated every build, poteantially leading to stale version data. This
commit adds a custom build target, git-version, which updates version.hpp
before the components library is built.
---
 CMakeLists.txt            | 25 ++-----------------------
 cmake/GitVersion.cmake    | 24 ++++++++++++++++++++++++
 components/CMakeLists.txt | 23 ++++++++++++++++++++++-
 3 files changed, 48 insertions(+), 24 deletions(-)
 create mode 100644 cmake/GitVersion.cmake

diff --git a/CMakeLists.txt b/CMakeLists.txt
index d7c85818e..323b743bc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -20,33 +20,13 @@ set(OPENMW_VERSION_TAGHASH "")
 
 set(OPENMW_VERSION "${OPENMW_VERSION_MAJOR}.${OPENMW_VERSION_MINOR}.${OPENMW_VERSION_RELEASE}")
 
+set(GIT_CHECKOUT FALSE)
 if(EXISTS ${PROJECT_SOURCE_DIR}/.git)
     if(NOT EXISTS ${PROJECT_SOURCE_DIR}/.git/shallow)
         find_package(Git)
 
         if(GIT_FOUND)
-            execute_process (
-                COMMAND "${GIT_EXECUTABLE}" rev-list --tags --max-count=1
-                WORKING_DIRECTORY "${PROJECT_SOURCE_DIR}"
-                RESULT_VARIABLE EXITCODE1
-                OUTPUT_VARIABLE TAGHASH
-                OUTPUT_STRIP_TRAILING_WHITESPACE)
-
-            execute_process (
-                COMMAND "${GIT_EXECUTABLE}" rev-parse HEAD
-                WORKING_DIRECTORY "${PROJECT_SOURCE_DIR}"
-                RESULT_VARIABLE EXITCODE2
-                OUTPUT_VARIABLE COMMITHASH
-                OUTPUT_STRIP_TRAILING_WHITESPACE)
-
-            string (COMPARE EQUAL "${EXITCODE1}:${EXITCODE2}" "0:0" SUCCESS)
-            if (SUCCESS)
-                set(OPENMW_VERSION_COMMITHASH "${COMMITHASH}")
-                set(OPENMW_VERSION_TAGHASH "${TAGHASH}")
-                message(STATUS "OpenMW version ${OPENMW_VERSION}")
-            else (SUCCESS)
-                message(WARNING "Failed to get valid version information from Git")
-            endif (SUCCESS)
+            set(GIT_CHECKOUT TRUE)
         else(GIT_FOUND)
             message(WARNING "Git executable not found")
         endif(GIT_FOUND)
@@ -874,4 +854,3 @@ if (DOXYGEN_FOUND)
         WORKING_DIRECTORY ${OpenMW_BINARY_DIR}
         COMMENT "Generating documentation for the github-pages at ${DOXYGEN_PAGES_OUTPUT_DIR}" VERBATIM)
 endif ()
-
diff --git a/cmake/GitVersion.cmake b/cmake/GitVersion.cmake
new file mode 100644
index 000000000..0087461a1
--- /dev/null
+++ b/cmake/GitVersion.cmake
@@ -0,0 +1,24 @@
+execute_process (
+    COMMAND ${GIT_EXECUTABLE} rev-list --tags --max-count=1
+    WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
+    RESULT_VARIABLE EXITCODE1
+    OUTPUT_VARIABLE TAGHASH
+    OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+execute_process (
+    COMMAND ${GIT_EXECUTABLE} rev-parse HEAD
+    WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
+    RESULT_VARIABLE EXITCODE2
+    OUTPUT_VARIABLE COMMITHASH
+    OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+string (COMPARE EQUAL "${EXITCODE1}:${EXITCODE2}" "0:0" SUCCESS)
+if (SUCCESS)
+    set(OPENMW_VERSION_COMMITHASH "${COMMITHASH}")
+    set(OPENMW_VERSION_TAGHASH "${TAGHASH}")
+    message(STATUS "OpenMW version ${OPENMW_VERSION}")
+else (SUCCESS)
+    message(WARNING "Failed to get valid version information from Git")
+endif (SUCCESS)
+
+configure_file(${VERSION_HPP_IN} ${VERSION_HPP})
diff --git a/components/CMakeLists.txt b/components/CMakeLists.txt
index 6918b87a7..1e400f779 100644
--- a/components/CMakeLists.txt
+++ b/components/CMakeLists.txt
@@ -2,7 +2,24 @@ project (Components)
 set (CMAKE_BUILD_TYPE DEBUG)
 
 # Version file
-configure_file("${CMAKE_CURRENT_SOURCE_DIR}/version/version.hpp.cmake" "${CMAKE_CURRENT_SOURCE_DIR}/version/version.hpp")
+set (VERSION_HPP_IN ${CMAKE_CURRENT_SOURCE_DIR}/version/version.hpp.cmake)
+set (VERSION_HPP ${CMAKE_CURRENT_SOURCE_DIR}/version/version.hpp)
+if (GIT_CHECKOUT)
+    add_custom_target (git-version
+        COMMAND ${CMAKE_COMMAND}
+	    -DGIT_EXECUTABLE=${GIT_EXECUTABLE}
+            -DPROJECT_SOURCE_DIR=${PROJECT_SOURCE_DIR}
+	    -DVERSION_HPP_IN=${VERSION_HPP_IN}
+	    -DVERSION_HPP=${VERSION_HPP}
+	    -DOPENMW_VERSION_MAJOR=${OPENMW_VERSION_MAJOR}
+	    -DOPENMW_VERSION_MINOR=${OPENMW_VERSION_MINOR}
+	    -DOPENMW_VERSION_RELEASE=${OPENMW_VERSION_RELEASE}
+	    -DOPENMW_VERSION=${OPENMW_VERSION}
+            -P ${CMAKE_CURRENT_SOURCE_DIR}/../cmake/GitVersion.cmake
+	    VERBATIM)
+else (GIT_CHECKOUT)
+    configure_file(${VERSION_HPP_IN} ${VERSION_HPP})
+endif (GIT_CHECKOUT)
 
 # source files
 
@@ -145,6 +162,10 @@ add_library(components STATIC ${COMPONENT_FILES} ${MOC_SRCS} ${ESM_UI_HDR})
 
 target_link_libraries(components ${Boost_LIBRARIES} ${OGRE_LIBRARIES})
 
+if (GIT_CHECKOUT)
+    add_dependencies (components git-version)
+endif (GIT_CHECKOUT)
+
 # Fix for not visible pthreads functions for linker with glibc 2.15
 if (UNIX AND NOT APPLE)
 target_link_libraries(components ${CMAKE_THREAD_LIBS_INIT})