# Copyright 2024 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

# This file exports variables containing the currently checked-out git revisions
# of the following third-party repositories:
#
#  - gwp_asan_git_revision
#  - llvm_libc_git_revision
#  - scudo_git_revision
#
# They can be used during soft-migrations in conditional statements to stay
# compatible with both the old and the new revision at the same time, e.g.:
#
#   libc_source_set("scudo-allocator") {
#     ...
#     if (scudo_git_revision != "<git hash of the old revision>") {
#       sources += [ "file_that_only_exists_in_the_new_revision.cpp" ]
#     }
#   }

import("//build/checkout.gni")
import("libc.gni")

_gwp_asan_git_path = "${gwp_asan}/.git"
_llvm_libc_git_path = "${llvm_libc}/.git"
_scudo_git_path = "${scudo}/.git"

# If submodules are in use, their .git is actually a text file pointing to the
# real git directory, which is stored inside the root project's .git directory.
# For instance, third_party/scudo/src/.git will contain:
#   gitdir: ../../../.git/modules/third_party%2fscudo%2fsrc
if (submodules) {
  _gwp_asan_git_link = read_file(_gwp_asan_git_path, "string")
  _gwp_asan_git_link_split = string_split(_gwp_asan_git_link)
  assert(_gwp_asan_git_link_split[0] == "gitdir:")
  _gwp_asan_git_path = "${gwp_asan}/${_gwp_asan_git_link_split[1]}"

  _llvm_libc_git_link = read_file(_llvm_libc_git_path, "string")
  _llvm_libc_git_link_split = string_split(_llvm_libc_git_link)
  assert(_llvm_libc_git_link_split[0] == "gitdir:")
  _llvm_libc_git_path = "${llvm_libc}/${_llvm_libc_git_link_split[1]}"

  _scudo_git_link = read_file(_scudo_git_path, "string")
  _scudo_git_link_split = string_split(_scudo_git_link)
  assert(_scudo_git_link_split[0] == "gitdir:")
  _scudo_git_path = "${scudo}/${_scudo_git_link_split[1]}"
}

libc_git_revisions = {
  gwp_asan = read_file("${_gwp_asan_git_path}/HEAD", "trim string")
  llvm_libc = read_file("${_llvm_libc_git_path}/HEAD", "trim string")
  scudo = read_file("${_scudo_git_path}/HEAD", "trim string")
}