1 files changed, 67 insertions, 0 deletions
diff --git a/cmake/Format.cmake b/cmake/Format.cmake
new file mode 100644
index 0000000000..4115e66705
--- /dev/null
+++ b/cmake/Format.cmake
@@ -0,0 +1,67 @@
+# Returns a list of all files that has been changed in current branch compared
+# to master branch. This includes unstaged, staged and committed files.
+function(get_changed_files outvar)
+  set(default_branch master)
+
+  execute_process(
+    COMMAND git branch --show-current
+    OUTPUT_VARIABLE current_branch
+    OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+  execute_process(
+    COMMAND git merge-base ${default_branch} ${current_branch}
+    OUTPUT_VARIABLE ancestor_commit
+    OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+  # Changed files that have been committed
+  execute_process(
+    COMMAND git diff --name-only ${ancestor_commit}...${current_branch}
+    OUTPUT_VARIABLE committed_files
+    OUTPUT_STRIP_TRAILING_WHITESPACE)
+  separate_arguments(committed_files NATIVE_COMMAND ${committed_files})
+
+  # Unstaged files
+  execute_process(
+    COMMAND git diff --name-only
+    OUTPUT_VARIABLE unstaged_files
+    OUTPUT_STRIP_TRAILING_WHITESPACE)
+  separate_arguments(unstaged_files NATIVE_COMMAND ${unstaged_files})
+
+  # Staged files
+  execute_process(
+    COMMAND git diff --cached --name-only
+    OUTPUT_VARIABLE staged_files
+    OUTPUT_STRIP_TRAILING_WHITESPACE)
+  separate_arguments(staged_files NATIVE_COMMAND ${staged_files})
+
+  set(files ${committed_files} ${unstaged_files} ${staged_files})
+  list(REMOVE_DUPLICATES files)
+
+  set(${outvar} "${files}" PARENT_SCOPE)
+endfunction()
+
+get_changed_files(changed_files)
+
+if(LANG STREQUAL c)
+  list(FILTER changed_files INCLUDE REGEX "\\.[ch]$")
+  list(FILTER changed_files INCLUDE REGEX "^src/nvim/")
+
+  if(changed_files)
+    if(FORMAT_PRG)
+      execute_process(COMMAND ${FORMAT_PRG} -c "src/uncrustify.cfg" --replace --no-backup ${changed_files})
+    else()
+      message(STATUS "Uncrustify not found. Skip formatting C files.")
+    endif()
+  endif()
+elseif(LANG STREQUAL lua)
+  list(FILTER changed_files INCLUDE REGEX "\\.lua$")
+  list(FILTER changed_files INCLUDE REGEX "^runtime/")
+
+  if(changed_files)
+    if(FORMAT_PRG)
+      execute_process(COMMAND ${FORMAT_PRG} ${changed_files})
+    else()
+      message(STATUS "Stylua not found. Skip formatting lua files.")
+    endif()
+  endif()
+endif()