Author: Andy Green <andy@warmcat.com>
Date: Sat Apr 25 14:08:37 2026 +0100

build: Generate dynamic git hash for sai-builder


diff --git a/cmake/GetGitHash.cmake b/cmake/GetGitHash.cmake
new file mode 100644
index 0000000..a3a0da7
--- /dev/null
+++ b/cmake/GetGitHash.cmake
@@ -0,0 +1,22 @@
+find_package(Git)
+if(GIT_EXECUTABLE)
+    execute_process(
+        COMMAND "${GIT_EXECUTABLE}" describe --tags --always
+        WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}"
+        OUTPUT_VARIABLE GIT_HASH
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+    )
+else()
+    set(GIT_HASH "unknown")
+endif()
+
+set(NEW_HASH_FILE_CONTENT "#define SAI_BUILD_INFO \"${CPACK_PACKAGE_VERSION}-${GIT_HASH}\"\n")
+
+if(EXISTS "${OUTPUT_FILE}")
+    file(READ "${OUTPUT_FILE}" OLD_HASH_FILE_CONTENT)
+    if(NOT "${OLD_HASH_FILE_CONTENT}" STREQUAL "${NEW_HASH_FILE_CONTENT}")
+        file(WRITE "${OUTPUT_FILE}" "${NEW_HASH_FILE_CONTENT}")
+    endif()
+else()
+    file(WRITE "${OUTPUT_FILE}" "${NEW_HASH_FILE_CONTENT}")
+endif()