set path for pkg-config when using sysroot

tools/linux/pkg-config-wrapper

@@ -0,0 +1,49 @@
+#!/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.
+
+set -o nounset
+set -o errexit
+
+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
+
+rewrite=`dirname $0`/rewrite_dirs.py
+package=${!#}
+
+libdir=$root/usr/$libpath/pkgconfig:$root/usr/share/pkgconfig
+
+set -e
+# Some sysroots, like the Chromium OS ones, may generate paths that are not
+# relative to the sysroot. For example,
+# /path/to/chroot/build/x86-generic/usr/lib/pkgconfig/pkg.pc may have all paths
+# relative to /path/to/chroot (i.e. prefix=/build/x86-generic/usr) instead of
+# relative to /path/to/chroot/build/x86-generic (i.e prefix=/usr).
+# To support this correctly, it's necessary to extract the prefix to strip from
+# pkg-config's |prefix| variable.
+prefix=`PKG_CONFIG_LIBDIR=$libdir pkg-config --variable=prefix "$package" | sed -e 's|/usr$||'`
+result=`PKG_CONFIG_LIBDIR=$libdir pkg-config "$@"`
+echo "$result"| $rewrite --sysroot "$root" --strip-prefix "$prefix"

tools/linux/rewrite_dirs.py

@@ -0,0 +1,71 @@
+#!/usr/bin/env python
+# Copyright (c) 2011 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.
+
+"""Rewrites paths in -I, -L and other option to be relative to a sysroot."""
+
+import sys
+import os
+import optparse
+
+REWRITE_PREFIX = ['-I',
+                  '-idirafter',
+                  '-imacros',
+                  '-imultilib',
+                  '-include',
+                  '-iprefix',
+                  '-iquote',
+                  '-isystem',
+                  '-L']
+
+def RewritePath(path, opts):
+  """Rewrites a path by stripping the prefix and prepending the sysroot."""
+  sysroot = opts.sysroot
+  prefix = opts.strip_prefix
+  if os.path.isabs(path) and not path.startswith(sysroot):
+    if path.startswith(prefix):
+      path = path[len(prefix):]
+    path = path.lstrip('/')
+    return os.path.join(sysroot, path)
+  else:
+    return path
+
+
+def RewriteLine(line, opts):
+  """Rewrites all the paths in recognized options."""
+  args = line.split()
+  count = len(args)
+  i = 0
+  while i < count:
+    for prefix in REWRITE_PREFIX:
+      # The option can be either in the form "-I /path/to/dir" or
+      # "-I/path/to/dir" so handle both.
+      if args[i] == prefix:
+        i += 1
+        try:
+          args[i] = RewritePath(args[i], opts)
+        except IndexError:
+          sys.stderr.write('Missing argument following %s\n' % prefix)
+          break
+      elif args[i].startswith(prefix):
+        args[i] = prefix + RewritePath(args[i][len(prefix):], opts)
+    i += 1
+
+  return ' '.join(args)
+
+
+def main(argv):
+  parser = optparse.OptionParser()
+  parser.add_option('-s', '--sysroot', default='/', help='sysroot to prepend')
+  parser.add_option('-p', '--strip-prefix', default='', help='prefix to strip')
+  opts, args = parser.parse_args(argv[1:])
+
+  for line in sys.stdin.readlines():
+    line = RewriteLine(line.strip(), opts)
+    print line
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))