Add automatic generation of version and build type headers for compilation

This change replaces the static version and build type header file generation
by CMake with dynamic CMake targets to generate the version file whenever a Make
target is executed. Thus, there is no need anymore to reconfigure and rerun
CMake after the repository version or build configuration has changed.

1 files changed, 27 insertions, 0 deletions

diff --git a/cmake/Build.cmake b/cmake/Build.cmake
new file mode 100644
index 0000000..bad9755
--- /dev/null
+++ b/cmake/Build.cmake
@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) 2020 Manuel Bentele <development@manuel-bentele.de>
+#
+
+macro(gen_build_type BUILD_INPUT_FILE_TEMPLATE BUILD_OUTPUT_FILE)
+    get_filename_component(BUILD_OUTPUT_FILENAME ${BUILD_OUTPUT_FILE} NAME)
+    # command that will trigger a rebuild of build.h every time
+    add_custom_command(OUTPUT regenerate-build-file
+                       COMMAND ${CMAKE_COMMAND} -E sleep 0
+                       COMMENT "Trigger generating ${BUILD_OUTPUT_FILENAME}")
+
+    # call the GenerateBuild.cmake file to generate the build.h file
+    add_custom_command(OUTPUT ${BUILD_OUTPUT_FILE}
+                       COMMAND ${CMAKE_COMMAND} -D BUILD_INPUT_FILE_TEMPLATE=${BUILD_INPUT_FILE_TEMPLATE}
+                                                -D BUILD_OUTPUT_FILE=${BUILD_OUTPUT_FILE}
+                                                -D BUILD_TYPE=${CMAKE_BUILD_TYPE}
+                                                -P ${PROJECT_MODULES_DIR}/GenerateBuild.cmake
+                       COMMENT "Generating ${BUILD_OUTPUT_FILENAME}"
+                       DEPENDS regenerate-build-file)
+    add_custom_target(xloop-generate-build DEPENDS ${BUILD_OUTPUT_FILE})
+
+    # create target to expose project build type
+    add_library(xloop-build INTERFACE)
+    target_include_directories(xloop-build INTERFACE ${PROJECT_INCLUDE_GEN_DIR})
+    add_dependencies(xloop-build xloop-generate-build)
+endmacro(gen_build_type BUILD_INPUT_FILE_TEMPLATE BUILD_OUTPUT_FILE)