From a01f34ec7928e8526d7f42f324e529c2de43fbf4 Mon Sep 17 00:00:00 2001
From: Jan Holthuis <jan.holthuis@ruhr-uni-bochum.de>
Date: Fri, 7 May 2021 13:15:26 +0200
Subject: CMake: Fetch latest Git information on build without reconfig

---
 cmake/modules/GitInfo.cmake | 65 +++++++++++++++++++++++++++++++++++++++++++++
 cmake/scripts/gitinfo.cmake |  3 +++
 2 files changed, 68 insertions(+)
 create mode 100644 cmake/modules/GitInfo.cmake
 create mode 100644 cmake/scripts/gitinfo.cmake

(limited to 'cmake')

diff --git a/cmake/modules/GitInfo.cmake b/cmake/modules/GitInfo.cmake
new file mode 100644
index 0000000000..ae74f9eb1d
--- /dev/null
+++ b/cmake/modules/GitInfo.cmake
@@ -0,0 +1,65 @@
+# Get the current commit ref
+execute_process(
+  COMMAND git describe --tags --always --dirty=-modified
+  WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
+  OUTPUT_VARIABLE GIT_DESCRIBE
+  OUTPUT_STRIP_TRAILING_WHITESPACE
+  ERROR_QUIET
+)
+if(NOT GIT_DESCRIBE)
+  message(NOTICE "Git describe: unknown")
+else()
+  message(NOTICE "Git describe: ${GIT_DESCRIBE}")
+  string(REGEX MATCH "-modified$" GIT_DIRTY "${GIT_DESCRIBE}")
+  if (GIT_DIRTY)
+    message("Git worktree modified: yes")
+    set(GIT_DIRTY 1)
+  else()
+    message(NOTICE "Git worktree modified: no")
+    set(GIT_DIRTY 0)
+  endif()
+endif()
+
+# Get the current working branch
+execute_process(
+  COMMAND git rev-parse --abbrev-ref HEAD
+  WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
+  OUTPUT_VARIABLE GIT_BRANCH
+  OUTPUT_STRIP_TRAILING_WHITESPACE
+  ERROR_QUIET
+)
+if(NOT GIT_BRANCH)
+  message(NOTICE "Git branch: unknown")
+else()
+  message(NOTICE "Git branch: ${GIT_BRANCH}")
+endif()
+
+# Get the current commit date
+execute_process(
+  COMMAND git show --quiet --format=%cI --date=short
+  WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
+  OUTPUT_VARIABLE GIT_COMMIT_DATE
+  OUTPUT_STRIP_TRAILING_WHITESPACE
+  ERROR_QUIET
+)
+if(NOT GIT_COMMIT_DATE)
+  message(NOTICE "Git commit date: unknown")
+else()
+  message(NOTICE "Git commit date: ${GIT_COMMIT_DATE}")
+  string(REGEX MATCH "^[0-9][0-9][0-9][0-9]" GIT_COMMIT_YEAR "${GIT_COMMIT_DATE}")
+  message(NOTICE "Git commit year: ${GIT_COMMIT_YEAR}")
+endif()
+
+# Get the number of commits on the working branch
+execute_process(
+  COMMAND git rev-list --count --first-parent HEAD
+  WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
+  OUTPUT_VARIABLE GIT_COMMIT_COUNT
+  OUTPUT_STRIP_TRAILING_WHITESPACE
+  ERROR_QUIET
+)
+if(NOT GIT_COMMIT_COUNT)
+  message(NOTICE "Git commit count: unknown")
+else()
+  message(NOTICE "Git commit count: ${GIT_COMMIT_COUNT}")
+endif()
diff --git a/cmake/scripts/gitinfo.cmake b/cmake/scripts/gitinfo.cmake
new file mode 100644
index 0000000000..7ff8a599e0
--- /dev/null
+++ b/cmake/scripts/gitinfo.cmake
@@ -0,0 +1,3 @@
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules")
+include(GitInfo)
+configure_file("${INPUT_FILE}" "${OUTPUT_FILE}" @ONLY)
-- 
cgit v1.2.3