ota deployment script, lots of other fun goodies too

main/version.cmake

@@ -1,7 +1,25 @@
 # version.cmake
+#
+# Dual-mode. When included from CMakeLists.txt it runs once at configure
+# time (seeding ${CMAKE_BINARY_DIR}/version.h so the first build has the
+# file). When invoked as a standalone script via `cmake -P` with SRC_DIR
+# and BIN_DIR set, it re-runs at build time so the SHA / dirty flag stay
+# current as commits happen between builds.
+
+if(NOT DEFINED SRC_DIR)
+    set(SRC_DIR ${CMAKE_CURRENT_LIST_DIR})
+endif()
+if(NOT DEFINED BIN_DIR)
+    set(BIN_DIR ${CMAKE_BINARY_DIR})
+endif()
+
+# Parent dir of the main/ component is the firmware project root, which
+# is inside the outer git repo.
+get_filename_component(_GIT_WORK_DIR ${SRC_DIR} DIRECTORY)
+
 execute_process(
     COMMAND git describe --tags --always --dirty
-    WORKING_DIRECTORY ${CMAKE_CURRENT_LIST_DIR}/..
+    WORKING_DIRECTORY ${_GIT_WORK_DIR}
     OUTPUT_VARIABLE GIT_VERSION
     OUTPUT_STRIP_TRAILING_WHITESPACE
     ERROR_QUIET
@@ -9,29 +27,44 @@ execute_process(
 
 execute_process(
     COMMAND git rev-parse --abbrev-ref HEAD
-    WORKING_DIRECTORY ${CMAKE_CURRENT_LIST_DIR}/..
+    WORKING_DIRECTORY ${_GIT_WORK_DIR}
     OUTPUT_VARIABLE GIT_BRANCH
     OUTPUT_STRIP_TRAILING_WHITESPACE
     ERROR_QUIET
 )
 
+execute_process(
+    COMMAND git rev-parse --short HEAD
+    WORKING_DIRECTORY ${_GIT_WORK_DIR}
+    OUTPUT_VARIABLE GIT_SHA
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+    ERROR_QUIET
+)
+
 string(TIMESTAMP BUILD_DATE "%Y-%m-%d %H:%M:%S" UTC)
 
-# Fallback if not in a git repo
 if(NOT GIT_VERSION)
     set(GIT_VERSION "unknown")
 endif()
-
 if(NOT GIT_BRANCH)
     set(GIT_BRANCH "unknown")
 endif()
+if(NOT GIT_SHA)
+    set(GIT_SHA "0000000")
+endif()
 
-message(STATUS "Firmware Version: ${GIT_VERSION}")
-message(STATUS "Git Branch: ${GIT_BRANCH}")
-message(STATUS "Build Date: ${BUILD_DATE}")
-
+# configure_file only touches the output file when content actually changes
+# — ninja / make won't needlessly re-compile translation units that include
+# version.h if nothing is different.
 configure_file(
-    ${CMAKE_CURRENT_LIST_DIR}/version.h.in
-    ${CMAKE_BINARY_DIR}/version.h
+    ${SRC_DIR}/version.h.in
+    ${BIN_DIR}/version.h
     @ONLY
-)
+)
+
+if(CMAKE_SCRIPT_MODE_FILE)
+    # Standalone -P invocation: quiet success.
+else()
+    message(STATUS "Firmware Version: ${GIT_VERSION}  Branch: ${GIT_BRANCH}  SHA: ${GIT_SHA}")
+    message(STATUS "Build Date: ${BUILD_DATE}")
+endif()