libcxx/utils/clang-format-merge-driver.sh

   1 #!/usr/bin/env bash
   2
   3 # This script can be installed in .git/config to allow rebasing old patches across
   4 # libc++'s clang-format of the whole tree. Most contributors should not require that
   5 # since they don't have many pre-clang-format patches lying around. This script is to
   6 # make it easier for contributors that do have such patches.
   7 #
   8 # The script is installed by running the following from the root of your repository:
   9 #
  10 #   $ git config merge.libcxx-reformat.name "Run clang-format when rebasing libc++ patches"
  11 #   $ git config merge.libcxx-reformat.driver "libcxx/utils/clang-format-merge-driver.sh %O %A %B %P"
  12 #
  13 # This is based on https://github.com/nico/hack/blob/main/notes/auto_git_rebase_across_mechanical_changes.md.
  14 # Many thanks to Nico Weber for paving the way here.
  15
  16 # Path to the file's contents at the ancestor's version.
  17 base="$1"
  18
  19 # Path to the file's contents at the current version.
  20 current="$2"
  21
  22 # Path to the file's contents at the other branch's version (for nonlinear histories, there might be multiple other branches).
  23 other="$3"
  24
  25 # The path of the file in the repository.
  26 path="$4"
  27
  28 clang-format --style=file --assume-filename="$path" < "$base" > "$base.tmp"
  29 mv "$base.tmp" "$base"
  30
  31 clang-format --style=file --assume-filename="$path" < "$current" > "$current.tmp"
  32 mv "$current.tmp" "$current"
  33
  34 clang-format --style=file --assume-filename="$path" < "$other" > "$other.tmp"
  35 mv "$other.tmp" "$other"
  36
  37 git merge-file -Lcurrent -Lbase -Lother "$current" "$base" "$other"