CMake: Avoid call of find_package(Git) for every compile with buildinfo enabled

This is a bit tricky, find_package(Git) was only used to check if git is installed
and actual git command was assumed to be in the PATH (while ideally it should have
been GIT_COMMAND variable).

This commit makes re-compile output cleaner, especially when using Ninja.

Adding proper GIT_COMMAND to buildinfo.cmake is also possible via argument.

Reviewers: campbellbarton

Reviewed By: campbellbarton

Differential Revision: https://developer.blender.org/D1847

1 files changed, 83 insertions, 87 deletions

diff --git a/build_files/cmake/buildinfo.cmake b/build_files/cmake/buildinfo.cmake
index 1f996b30ba6..4caa4a954ea 100644
--- a/build_files/cmake/buildinfo.cmake
+++ b/build_files/cmake/buildinfo.cmake
@@ -9,124 +9,120 @@ set(MY_WC_COMMIT_TIMESTAMP 0)
 
 # Guess if this is a git working copy and then look up the revision
 if(EXISTS ${SOURCE_DIR}/.git)
-	# The FindGit.cmake module is part of the standard distribution
-	find_package(Git)
-	if(GIT_FOUND)
-		execute_process(COMMAND git rev-parse --abbrev-ref HEAD
+	execute_process(COMMAND git rev-parse --abbrev-ref HEAD
+	                WORKING_DIRECTORY ${SOURCE_DIR}
+	                OUTPUT_VARIABLE MY_WC_BRANCH
+	                OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+	if(MY_WC_BRANCH STREQUAL "HEAD")
+		# Detached HEAD, check whether commit hash is reachable
+		# in the master branch
+		execute_process(COMMAND git rev-parse --short HEAD
 		                WORKING_DIRECTORY ${SOURCE_DIR}
-		                OUTPUT_VARIABLE MY_WC_BRANCH
+		                OUTPUT_VARIABLE MY_WC_HASH
 		                OUTPUT_STRIP_TRAILING_WHITESPACE)
 
-		if(MY_WC_BRANCH STREQUAL "HEAD")
-			# Detached HEAD, check whether commit hash is reachable
-			# in the master branch
-			execute_process(COMMAND git rev-parse --short HEAD
+		execute_process(COMMAND git branch --list master --contains ${MY_WC_HASH}
+		                WORKING_DIRECTORY ${SOURCE_DIR}
+		                OUTPUT_VARIABLE _git_contains_check
+		                OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+		STRING(REGEX REPLACE "^[ \t]+" "" _git_contains_check "${_git_contains_check}")
+		if(_git_contains_check STREQUAL "master")
+			set(MY_WC_BRANCH "master")
+		else()
+			execute_process(COMMAND git show-ref --tags -d
 			                WORKING_DIRECTORY ${SOURCE_DIR}
-			                OUTPUT_VARIABLE MY_WC_HASH
+			                OUTPUT_VARIABLE _git_tag_hashes
 			                OUTPUT_STRIP_TRAILING_WHITESPACE)
 
-			execute_process(COMMAND git branch --list master --contains ${MY_WC_HASH}
+			execute_process(COMMAND git rev-parse HEAD
 			                WORKING_DIRECTORY ${SOURCE_DIR}
-			                OUTPUT_VARIABLE _git_contains_check
+			                OUTPUT_VARIABLE _git_head_hash
 			                OUTPUT_STRIP_TRAILING_WHITESPACE)
 
-			STRING(REGEX REPLACE "^[ \t]+" "" _git_contains_check "${_git_contains_check}")
-			if(_git_contains_check STREQUAL "master")
+			if(_git_tag_hashes MATCHES "${_git_head_hash}")
 				set(MY_WC_BRANCH "master")
-			else()
-				execute_process(COMMAND git show-ref --tags -d
-				                WORKING_DIRECTORY ${SOURCE_DIR}
-				                OUTPUT_VARIABLE _git_tag_hashes
-				                OUTPUT_STRIP_TRAILING_WHITESPACE)
-
-				execute_process(COMMAND git rev-parse HEAD
-				                WORKING_DIRECTORY ${SOURCE_DIR}
-				                OUTPUT_VARIABLE _git_head_hash
-				                OUTPUT_STRIP_TRAILING_WHITESPACE)
-
-				if(_git_tag_hashes MATCHES "${_git_head_hash}")
-					set(MY_WC_BRANCH "master")
-				endif()
-
-				unset(_git_tag_hashes)
-				unset(_git_head_hashs)
 			endif()
 
+			unset(_git_tag_hashes)
+			unset(_git_head_hashs)
+		endif()
+
 
-			unset(_git_contains_check)
+		unset(_git_contains_check)
+	else()
+		execute_process(COMMAND git log HEAD..@{u}
+		                WORKING_DIRECTORY ${SOURCE_DIR}
+		                OUTPUT_VARIABLE _git_below_check
+		                OUTPUT_STRIP_TRAILING_WHITESPACE
+		                ERROR_QUIET)
+		if(NOT _git_below_check STREQUAL "")
+			# If there're commits between HEAD and upstream this means
+			# that we're reset-ed to older revision. Use it's hash then.
+			execute_process(COMMAND git rev-parse --short HEAD
+			                WORKING_DIRECTORY ${SOURCE_DIR}
+			                OUTPUT_VARIABLE MY_WC_HASH
+			                OUTPUT_STRIP_TRAILING_WHITESPACE)
 		else()
-			execute_process(COMMAND git log HEAD..@{u}
+			execute_process(COMMAND git rev-parse --short @{u}
 			                WORKING_DIRECTORY ${SOURCE_DIR}
-			                OUTPUT_VARIABLE _git_below_check
+			                OUTPUT_VARIABLE MY_WC_HASH
 			                OUTPUT_STRIP_TRAILING_WHITESPACE
 			                ERROR_QUIET)
-			if(NOT _git_below_check STREQUAL "")
-				# If there're commits between HEAD and upstream this means
-				# that we're reset-ed to older revision. Use it's hash then.
+
+			if(MY_WC_HASH STREQUAL "")
+				# Local branch, not set to upstream.
+				# Well, let's use HEAD for now
 				execute_process(COMMAND git rev-parse --short HEAD
 				                WORKING_DIRECTORY ${SOURCE_DIR}
 				                OUTPUT_VARIABLE MY_WC_HASH
 				                OUTPUT_STRIP_TRAILING_WHITESPACE)
-			else()
-				execute_process(COMMAND git rev-parse --short @{u}
-				                WORKING_DIRECTORY ${SOURCE_DIR}
-				                OUTPUT_VARIABLE MY_WC_HASH
-				                OUTPUT_STRIP_TRAILING_WHITESPACE
-				                ERROR_QUIET)
-
-				if(MY_WC_HASH STREQUAL "")
-					# Local branch, not set to upstream.
-					# Well, let's use HEAD for now
-					execute_process(COMMAND git rev-parse --short HEAD
-					                WORKING_DIRECTORY ${SOURCE_DIR}
-					                OUTPUT_VARIABLE MY_WC_HASH
-					                OUTPUT_STRIP_TRAILING_WHITESPACE)
-				endif()
-			endif()
-
-			if(MY_WC_BRANCH MATCHES "^blender-v")
-				set(MY_WC_BRANCH "master")
 			endif()
-
-			unset(_git_below_check)
 		endif()
 
-		execute_process(COMMAND git log -1 --format=%ct
-		                WORKING_DIRECTORY ${SOURCE_DIR}
-		                OUTPUT_VARIABLE MY_WC_COMMIT_TIMESTAMP
-		                OUTPUT_STRIP_TRAILING_WHITESPACE)
-		# May fail in rare cases
-		if(MY_WC_COMMIT_TIMESTAMP STREQUAL "")
-			set(MY_WC_COMMIT_TIMESTAMP 0)
+		if(MY_WC_BRANCH MATCHES "^blender-v")
+			set(MY_WC_BRANCH "master")
 		endif()
 
-		# Update GIT index before getting dirty files
-		execute_process(COMMAND git update-index -q --refresh
-		                WORKING_DIRECTORY ${SOURCE_DIR}
-		                OUTPUT_STRIP_TRAILING_WHITESPACE)
+		unset(_git_below_check)
+	endif()
 
-		execute_process(COMMAND git diff-index --name-only HEAD --
-		                WORKING_DIRECTORY ${SOURCE_DIR}
-		                OUTPUT_VARIABLE _git_changed_files
-		                OUTPUT_STRIP_TRAILING_WHITESPACE)
+	execute_process(COMMAND git log -1 --format=%ct
+	                WORKING_DIRECTORY ${SOURCE_DIR}
+	                OUTPUT_VARIABLE MY_WC_COMMIT_TIMESTAMP
+	                OUTPUT_STRIP_TRAILING_WHITESPACE)
+	# May fail in rare cases
+	if(MY_WC_COMMIT_TIMESTAMP STREQUAL "")
+		set(MY_WC_COMMIT_TIMESTAMP 0)
+	endif()
 
-		if(NOT _git_changed_files STREQUAL "")
+	# Update GIT index before getting dirty files
+	execute_process(COMMAND git update-index -q --refresh
+	                WORKING_DIRECTORY ${SOURCE_DIR}
+	                OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+	execute_process(COMMAND git diff-index --name-only HEAD --
+	                WORKING_DIRECTORY ${SOURCE_DIR}
+	                OUTPUT_VARIABLE _git_changed_files
+	                OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+	if(NOT _git_changed_files STREQUAL "")
+		set(MY_WC_BRANCH "${MY_WC_BRANCH} (modified)")
+	else()
+		# Unpushed commits are also considered local modifications
+		execute_process(COMMAND git log @{u}..
+		                WORKING_DIRECTORY ${SOURCE_DIR}
+		                OUTPUT_VARIABLE _git_unpushed_log
+		                OUTPUT_STRIP_TRAILING_WHITESPACE
+		                ERROR_QUIET)
+		if(NOT _git_unpushed_log STREQUAL "")
 			set(MY_WC_BRANCH "${MY_WC_BRANCH} (modified)")
-		else()
-			# Unpushed commits are also considered local modifications
-			execute_process(COMMAND git log @{u}..
-			                WORKING_DIRECTORY ${SOURCE_DIR}
-			                OUTPUT_VARIABLE _git_unpushed_log
-			                OUTPUT_STRIP_TRAILING_WHITESPACE
-			                ERROR_QUIET)
-			if(NOT _git_unpushed_log STREQUAL "")
-				set(MY_WC_BRANCH "${MY_WC_BRANCH} (modified)")
-			endif()
-			unset(_git_unpushed_log)
 		endif()
-
-		unset(_git_changed_files)
+		unset(_git_unpushed_log)
 	endif()
+
+	unset(_git_changed_files)
 endif()
 
 # BUILD_PLATFORM and BUILD_PLATFORM are taken from CMake