#!/bin/bash
# Copyright (c) 2012 The Chromium 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 program wraps around pkg-config to generate the correct include and
# library paths when cross-compiling using a sysroot.
# The assumption is that the sysroot contains the .pc files in usr/lib/pkgconfig
# and usr/share/pkgconfig (relative to the sysroot) and that they output paths
# relative to some parent path of the sysroot.
# This assumption is valid for a range of sysroots, in particular: a
# LSB-compliant root filesystem mounted at the sysroot, and a board build
# directory of a Chromium OS chroot.
# Additional directories containing .pc files may be specified by setting
# the PKG_CONFIG_PATH environment variable- these will be prepended to the
# generated paths.

root="$1"
shift
target_arch="$1"
shift
libpath="$1"
shift

if [ -z "$root" -o -z "$target_arch" ]
then
  echo "usage: $0 /path/to/sysroot target_arch libdir [pkg-config-arguments] package" >&2
  exit 1
fi

if [ "$target_arch" = "x64" ]
then
  : ${libpath:="lib64"}
else
  : ${libpath:="lib"}
fi

rewrite=`dirname $0`/rewrite_dirs.py
package=${!#}

config_path=$root/usr/$libpath/pkgconfig:$root/usr/share/pkgconfig

# prepend any paths specified by the environment
if [ -n "$PKG_CONFIG_PATH" ]
then
  config_path="$PKG_CONFIG_PATH:$config_path"
fi

set -e
# Some sysroots, like the Chromium OS ones, may generate paths that are not
# relative to the sysroot. For example,
# /path/to/chroot/build/x86-generic/usr/lib/pkgconfig/pkg.pc may have all paths
# relative to /path/to/chroot (i.e. prefix=/build/x86-generic/usr) instead of
# relative to /path/to/chroot/build/x86-generic (i.e prefix=/usr).
# To support this correctly, it's necessary to extract the prefix to strip from
# pkg-config's |prefix| variable.
prefix=`PKG_CONFIG_PATH=$config_path pkg-config --variable=prefix "$package" | sed -e 's|/usr$||'`
result=`PKG_CONFIG_PATH=$config_path pkg-config "$@"`
echo "$result"| $rewrite --sysroot "$root" --strip-prefix "$prefix"