cc_wrapper.sh.tpl

#!/bin/bash
#
# Copyright 2021 The Bazel Authors. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# OS X relpath is not really working. This is a wrapper script around gcc
# to simulate relpath behavior.
#
# This wrapper uses install_name_tool to replace all paths in the binary
# (bazel-out/.../path/to/original/library.so) by the paths relative to
# the binary. It parses the command line to behave as rpath is supposed
# to work.
#
# See https://blogs.oracle.com/dipol/entry/dynamic_libraries_rpath_and_mac
# on how to set those paths for Mach-O binaries.

# shellcheck disable=SC1083

set -euo pipefail

# See note in toolchain/internal/configure.bzl where we define
# `wrapper_bin_prefix` for why this wrapper is needed.

if [[ -f %{toolchain_path_prefix}bin/clang ]]; then
  execroot_path=""
elif [[ ${BASH_SOURCE[0]} == "/"* ]]; then
  # Some consumers of `CcToolchainConfigInfo` (e.g. `cmake` from rules_foreign_cc)
  # change CWD and call $CC (this script) with its absolute path.
  # For cases like this, we'll try to find `clang` through an absolute path.
  # This script is at _execroot_/external/_repo_name_/bin/cc_wrapper.sh
  execroot_path="${BASH_SOURCE[0]%/*/*/*/*}/"
else
  echo >&2 "ERROR: could not find clang; PWD=\"${PWD}\"; PATH=\"${PATH}\"."
  exit 5
fi

function sanitize_option() {
  local -r opt=$1
  if [[ ${opt} == */cc_wrapper.sh ]]; then
    printf "%s" "${execroot_path}%{toolchain_path_prefix}bin/clang"
  elif [[ ${opt} =~ ^-fsanitize-(ignore|black)list=[^/] ]]; then
    # shellcheck disable=SC2206
    parts=(${opt/=/ }) # Split flag name and value into array.
    printf "%s" "${parts[0]}=${execroot_path}${parts[1]}"
  else
    printf "%s" "${opt}"
  fi
}

cmd=()
for ((i = 0; i <= $#; i++)); do
  if [[ ${!i} == @* ]]; then
    while IFS= read -r opt; do
      opt="$(
        set -e
        sanitize_option "${opt}"
      )"
      cmd+=("${opt}")
    done <"${!i:1}"
  else
    opt="$(
      set -e
      sanitize_option "${!i}"
    )"
    cmd+=("${opt}")
  fi
done

# Call the C++ compiler.
exec "${cmd[@]}"