[BUILD] add support to locate build directory out of Git directory

This patch adds support to locate the build directory for generated
artifacts out of the original checked out Git source code repository.

3 files changed, 11 insertions, 7 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 76f5190..542f2ec 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -65,7 +65,7 @@ set(INCLUDE_VERSION_HEADER ${PROJECT_INCLUDE_DIR}/dnbd3/version.h)
 set(INCLUDE_VERSION_HEADER_TEMPLATE ${PROJECT_INCLUDE_DIR}/dnbd3/version.h.in)
 set(INCLUDE_VERSION_HEADER_GENERATE ${PROJECT_INCLUDE_GEN_DIR}/dnbd3/version.h)
 set(INCLUDE_VERSION_HEADER_GENERATE_PREFIX ${PROJECT_INCLUDE_DIR_PREFIX}/dnbd3)
-gen_project_version(${INCLUDE_VERSION_HEADER} ${INCLUDE_VERSION_HEADER_TEMPLATE} ${INCLUDE_VERSION_HEADER_GENERATE})
+gen_project_version(${INCLUDE_VERSION_HEADER} ${INCLUDE_VERSION_HEADER_TEMPLATE} ${INCLUDE_VERSION_HEADER_GENERATE} ${GIT_EXECUTABLE} ${CMAKE_SOURCE_DIR})
 
 # generate project build type C header file from template
 # exposes dnbd3-generate-build and dnbd3-build target
@@ -102,7 +102,7 @@ endif(DNBD3_RELEASE_HARDEN AND CMAKE_BUILD_TYPE MATCHES "Release")
 # define packaging if Release build is enabled
 if(CMAKE_BUILD_TYPE MATCHES Release)
     # get version source package or Git repository
-    get_repository_version(REPOSITORY_VERSION ${INCLUDE_VERSION_HEADER} ${CMAKE_BUILD_TYPE})
+    get_repository_version(REPOSITORY_VERSION ${INCLUDE_VERSION_HEADER} ${CMAKE_BUILD_TYPE} ${GIT_EXECUTABLE} ${CMAKE_SOURCE_DIR})
 
     # define project version
     if(KernelHeaders_VERSION)
diff --git a/cmake/GenerateVersion.cmake b/cmake/GenerateVersion.cmake
index 8574ba7..e7c551b 100644
--- a/cmake/GenerateVersion.cmake
+++ b/cmake/GenerateVersion.cmake
@@ -11,7 +11,7 @@ set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH}
 include(Version)
 
 # get Git version of Git repository
-get_repository_version(DNBD3_VERSION ${VERSION_INPUT_FILE} ${VERSION_BUILD_TYPE})
+get_repository_version(DNBD3_VERSION ${VERSION_INPUT_FILE} ${VERSION_BUILD_TYPE} ${GIT_EXECUTABLE} ${REPOSITORY_DIR})
 
 # generate version header if header does not exists
 if(NOT EXISTS ${VERSION_INPUT_FILE})
diff --git a/cmake/Version.cmake b/cmake/Version.cmake
index 097afd5..5f63a31 100644
--- a/cmake/Version.cmake
+++ b/cmake/Version.cmake
@@ -3,7 +3,7 @@
 # Copyright (C) 2020 Manuel Bentele <development@manuel-bentele.de>
 #
 
-macro(gen_project_version VERSION_INPUT_FILE VERSION_INPUT_FILE_TEMPLATE VERSION_OUTPUT_FILE)
+macro(gen_project_version VERSION_INPUT_FILE VERSION_INPUT_FILE_TEMPLATE VERSION_OUTPUT_FILE GIT_EXECUTABLE REPOSITORY_DIR)
     get_filename_component(VERSION_OUTPUT_FILENAME ${VERSION_OUTPUT_FILE} NAME)
     # command that will trigger a rebuild of version.h every time
     add_custom_command(OUTPUT regenerate-version-file
@@ -17,6 +17,8 @@ macro(gen_project_version VERSION_INPUT_FILE VERSION_INPUT_FILE_TEMPLATE VERSION
                                                 -D VERSION_INPUT_FILE_TEMPLATE=${VERSION_INPUT_FILE_TEMPLATE}
                                                 -D VERSION_OUTPUT_FILE=${VERSION_OUTPUT_FILE}
                                                 -D VERSION_BUILD_TYPE=${CMAKE_BUILD_TYPE}
+                                                -D GIT_EXECUTABLE=${GIT_EXECUTABLE}
+                                                -D REPOSITORY_DIR=${REPOSITORY_DIR}
                                                 -P ${PROJECT_MODULES_DIR}/GenerateVersion.cmake
                        COMMENT "Generating ${VERSION_OUTPUT_FILENAME}"
                        DEPENDS regenerate-version-file)
@@ -29,7 +31,7 @@ macro(gen_project_version VERSION_INPUT_FILE VERSION_INPUT_FILE_TEMPLATE VERSION
 endmacro(gen_project_version VERSION_INPUT_FILE VERSION_INPUT_FILE_TEMPLATE VERSION_OUTPUT_FILE)
 
 # macro to get Git version information
-macro(get_repository_version REPOSITORY_VERSION VERSION_HEADER_FILE VERSION_BUILD_TYPE)
+macro(get_repository_version REPOSITORY_VERSION VERSION_HEADER_FILE VERSION_BUILD_TYPE GIT_EXECUTABLE REPOSITORY_DIR)
     # check if generated version header from source package is available
     if(EXISTS ${VERSION_HEADER_FILE})
         # get version information from the generated version header of the source package
@@ -38,7 +40,8 @@ macro(get_repository_version REPOSITORY_VERSION VERSION_HEADER_FILE VERSION_BUIL
         set(GIT_VERSION "${CMAKE_MATCH_1}")
     else(EXISTS ${VERSION_HEADER_FILE})
         # get detailed Git version information from Git repository
-        execute_process(COMMAND git describe HEAD
+        execute_process(COMMAND ${GIT_EXECUTABLE} describe HEAD
+                        WORKING_DIRECTORY ${REPOSITORY_DIR}
                         OUTPUT_VARIABLE GIT_VERSION
                         OUTPUT_STRIP_TRAILING_WHITESPACE)
 
@@ -51,7 +54,8 @@ macro(get_repository_version REPOSITORY_VERSION VERSION_HEADER_FILE VERSION_BUIL
         endif(GIT_VERSION STREQUAL "")
 
         # get status of Git repository
-        execute_process(COMMAND git status --porcelain
+        execute_process(COMMAND ${GIT_EXECUTABLE} status --porcelain
+                        WORKING_DIRECTORY ${REPOSITORY_DIR}
                         OUTPUT_VARIABLE GIT_STATUS
                         OUTPUT_STRIP_TRAILING_WHITESPACE)