1#!/usr/bin/env python
2# Copyright (c) 2013 The Chromium Authors. All rights reserved.
3# Use of this source code is governed by a BSD-style license that can be
4# found in the LICENSE file.
5
6import json
7import os
8import subprocess
9import sys
10import re
11from optparse import OptionParser
12
13# This script runs pkg-config, optionally filtering out some results, and
14# returns the result.
15#
16# The result will be [ <includes>, <cflags>, <libs>, <lib_dirs>, <ldflags> ]
17# where each member is itself a list of strings.
18#
19# You can filter out matches using "-v <regexp>" where all results from
20# pkgconfig matching the given regular expression will be ignored. You can
21# specify more than one regular expression my specifying "-v" more than once.
22#
23# You can specify a sysroot using "-s <sysroot>" where sysroot is the absolute
24# system path to the sysroot used for compiling. This script will attempt to
25# generate correct paths for the sysroot.
26#
27# When using a sysroot, you must also specify the architecture via
28# "-a <arch>" where arch is either "x86" or "x64".
29#
30# CrOS systemroots place pkgconfig files at <systemroot>/usr/share/pkgconfig
31# and one of <systemroot>/usr/lib/pkgconfig or <systemroot>/usr/lib64/pkgconfig
32# depending on whether the systemroot is for a 32 or 64 bit architecture. They
33# specify the 'lib' or 'lib64' of the pkgconfig path by defining the
34# 'system_libdir' variable in the args.gn file. pkg_config.gni communicates this
35# variable to this script with the "--system_libdir <system_libdir>" flag. If no
36# flag is provided, then pkgconfig files are assumed to come from
37# <systemroot>/usr/lib/pkgconfig.
38#
39# Additionally, you can specify the option --atleast-version. This will skip
40# the normal outputting of a dictionary and instead print true or false,
41# depending on the return value of pkg-config for the given package.
42
43
44def SetConfigPath(options):
45  """Set the PKG_CONFIG_LIBDIR environment variable.
46
47  This takes into account any sysroot and architecture specification from the
48  options on the given command line.
49  """
50
51  sysroot = options.sysroot
52  assert sysroot
53
54  # Compute the library path name based on the architecture.
55  arch = options.arch
56  if sysroot and not arch:
57    print "You must specify an architecture via -a if using a sysroot."
58    sys.exit(1)
59
60  libdir = sysroot + '/usr/' + options.system_libdir + '/pkgconfig'
61  libdir += ':' + sysroot + '/usr/share/pkgconfig'
62  os.environ['PKG_CONFIG_LIBDIR'] = libdir
63  return libdir
64
65
66def GetPkgConfigPrefixToStrip(args):
67  """Returns the prefix from pkg-config where packages are installed.
68
69  This returned prefix is the one that should be stripped from the beginning of
70  directory names to take into account sysroots.
71  """
72  # Some sysroots, like the Chromium OS ones, may generate paths that are not
73  # relative to the sysroot. For example,
74  # /path/to/chroot/build/x86-generic/usr/lib/pkgconfig/pkg.pc may have all
75  # paths relative to /path/to/chroot (i.e. prefix=/build/x86-generic/usr)
76  # instead of relative to /path/to/chroot/build/x86-generic (i.e prefix=/usr).
77  # To support this correctly, it's necessary to extract the prefix to strip
78  # from pkg-config's |prefix| variable.
79  prefix = subprocess.check_output(["pkg-config", "--variable=prefix"] + args,
80      env=os.environ)
81  if prefix[-4] == '/usr':
82    return prefix[4:]
83  return prefix
84
85
86def MatchesAnyRegexp(flag, list_of_regexps):
87  """Returns true if the first argument matches any regular expression in the
88  given list."""
89  for regexp in list_of_regexps:
90    if regexp.search(flag) != None:
91      return True
92  return False
93
94
95def RewritePath(path, strip_prefix, sysroot):
96  """Rewrites a path by stripping the prefix and prepending the sysroot."""
97  if os.path.isabs(path) and not path.startswith(sysroot):
98    if path.startswith(strip_prefix):
99      path = path[len(strip_prefix):]
100    path = path.lstrip('/')
101    return os.path.join(sysroot, path)
102  else:
103    return path
104
105
106def main():
107  # If this is run on non-Linux platforms, just return nothing and indicate
108  # success. This allows us to "kind of emulate" a Linux build from other
109  # platforms.
110  if "linux" not in sys.platform:
111    print "[[],[],[],[],[]]"
112    return 0
113
114  parser = OptionParser()
115  parser.add_option('-d', '--debug', action='store_true')
116  parser.add_option('-p', action='store', dest='pkg_config', type='string',
117                    default='pkg-config')
118  parser.add_option('-v', action='append', dest='strip_out', type='string')
119  parser.add_option('-s', action='store', dest='sysroot', type='string')
120  parser.add_option('-a', action='store', dest='arch', type='string')
121  parser.add_option('--system_libdir', action='store', dest='system_libdir',
122                    type='string', default='lib')
123  parser.add_option('--atleast-version', action='store',
124                    dest='atleast_version', type='string')
125  parser.add_option('--libdir', action='store_true', dest='libdir')
126  (options, args) = parser.parse_args()
127
128  # Make a list of regular expressions to strip out.
129  strip_out = []
130  if options.strip_out != None:
131    for regexp in options.strip_out:
132      strip_out.append(re.compile(regexp))
133
134  if options.sysroot:
135    libdir = SetConfigPath(options)
136    if options.debug:
137      sys.stderr.write('PKG_CONFIG_LIBDIR=%s\n' % libdir)
138    prefix = GetPkgConfigPrefixToStrip(args)
139  else:
140    prefix = ''
141
142  if options.atleast_version:
143    # When asking for the return value, just run pkg-config and print the return
144    # value, no need to do other work.
145    if not subprocess.call([options.pkg_config,
146                            "--atleast-version=" + options.atleast_version] +
147                            args):
148      print "true"
149    else:
150      print "false"
151    return 0
152
153  if options.libdir:
154    cmd = [options.pkg_config, "--variable=libdir"] + args
155    if options.debug:
156      sys.stderr.write('Running: %s\n' % cmd)
157    try:
158      libdir = subprocess.check_output(cmd)
159    except:
160      print "Error from pkg-config."
161      return 1
162    sys.stdout.write(libdir.strip())
163    return 0
164
165  cmd = [options.pkg_config, "--cflags", "--libs"] + args
166  if options.debug:
167    sys.stderr.write('Running: %s\n' % ' '.join(cmd))
168
169  try:
170    flag_string = subprocess.check_output(cmd)
171  except:
172    sys.stderr.write('Could not run pkg-config.\n')
173    return 1
174
175  # For now just split on spaces to get the args out. This will break if
176  # pkgconfig returns quoted things with spaces in them, but that doesn't seem
177  # to happen in practice.
178  all_flags = flag_string.strip().split(' ')
179
180
181  sysroot = options.sysroot
182  if not sysroot:
183    sysroot = ''
184
185  includes = []
186  cflags = []
187  libs = []
188  lib_dirs = []
189  ldflags = []
190
191  for flag in all_flags[:]:
192    if len(flag) == 0 or MatchesAnyRegexp(flag, strip_out):
193      continue;
194
195    if flag[:2] == '-l':
196      libs.append(RewritePath(flag[2:], prefix, sysroot))
197    elif flag[:2] == '-L':
198      lib_dirs.append(RewritePath(flag[2:], prefix, sysroot))
199    elif flag[:2] == '-I':
200      includes.append(RewritePath(flag[2:], prefix, sysroot))
201    elif flag[:3] == '-Wl':
202      ldflags.append(flag)
203    elif flag == '-pthread':
204      # Many libs specify "-pthread" which we don't need since we always include
205      # this anyway. Removing it here prevents a bunch of duplicate inclusions
206      # on the command line.
207      pass
208    else:
209      cflags.append(flag)
210
211  # Output a GN array, the first one is the cflags, the second are the libs. The
212  # JSON formatter prints GN compatible lists when everything is a list of
213  # strings.
214  print json.dumps([includes, cflags, libs, lib_dirs, ldflags])
215  return 0
216
217
218if __name__ == '__main__':
219  sys.exit(main())
220