build/config/linux/pkg-config.py

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