cmake: fix .ldc chksum fallback when no SOURCE_DIRECTORY/.git

marc-hb · lgirdwood · commit 5d66f1dac433 · 2021-12-24T22:15:13.000Z
Fixes old (Aug 2020) and untested commit b2a325a ("cmake: Handle empty SOF_SRC_HASH_LONG") which tried to use GIT_LOG_HASH as a fallback for the SOF_SRC_HASH .ldc checksum but always fell back on "0" instead because of a misunderstanding of cmake's surprisingly complex "if" operator. Before Zephyr this was not an issue in practice because GIT_LOG_HASH was empty anyway when SOURCE_DIRECTORY/.git was missing, so there was nothing to lose. For the Zephyr builds this will now use the SOF SHA1 as the .ldc checksum for now. Probably not ideal yet but far better than the current constant "0" which means no check at all. Also log the SOF_SRC_HASH fallback value now and change the second fallback (when GIT_LOG_HASH is also missing) from "0" to the searchable hexspeak "baadf00d". Signed-off-by: Marc Herbert <marc.herbert@intel.com>
diff --git a/scripts/cmake/version.cmake b/scripts/cmake/version.cmake
@@ -110,13 +110,14 @@ if(EXISTS ${SOF_ROOT_SOURCE_DIRECTORY}/.git/)
 	message(STATUS "Source content hash: ${SOF_SRC_HASH}. \
 Note: by design, source hash is broken by config changes. See #3890.")
 else() # Zephyr, tarball,...
-	if("${GIT_LOG_HASH}")
+	if(NOT "${GIT_LOG_HASH}" STREQUAL "")
 		string(SUBSTRING "${GIT_LOG_HASH}" 0 8 SOF_SRC_HASH)
 	else()
-		set(SOF_SRC_HASH "0")
+		set(SOF_SRC_HASH "baadf00d")
 	endif()
 	message(WARNING "${SOF_ROOT_SOURCE_DIRECTORY}/.git not found, \
-source content hash cannot computed. Using GIT_LOG_HASH for .ldc instead.")
+source content hash cannot computed for the .ldc. Using SOF_SRC_HASH=${SOF_SRC_HASH} \
+from GIT_LOG_HASH instead")
 endif()
 
 # for SOF_BUILD
