1#!/usr/bin/env python 2# Copyright (c) 2012 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 6""" 7Generates shim headers that mirror the directory structure of bundled headers, 8but just forward to the system ones. 9 10This allows seamless compilation against system headers with no changes 11to our source code. 12""" 13 14 15import optparse 16import os.path 17import sys 18 19 20SHIM_TEMPLATE = """ 21#if defined(OFFICIAL_BUILD) 22#error shim headers must not be used in official builds! 23#endif 24""" 25 26 27def GeneratorMain(argv): 28 parser = optparse.OptionParser() 29 parser.add_option('--headers-root', action='append') 30 parser.add_option('--define', action='append') 31 parser.add_option('--output-directory') 32 parser.add_option('--prefix', default='') 33 parser.add_option('--use-include-next', action='store_true') 34 parser.add_option('--outputs', action='store_true') 35 parser.add_option('--generate', action='store_true') 36 37 options, args = parser.parse_args(argv) 38 39 if not options.headers_root: 40 parser.error('Missing --headers-root parameter.') 41 if not options.output_directory: 42 parser.error('Missing --output-directory parameter.') 43 if not args: 44 parser.error('Missing arguments - header file names.') 45 46 source_tree_root = os.path.abspath( 47 os.path.join(os.path.dirname(__file__), '..', '..')) 48 49 for root in options.headers_root: 50 target_directory = os.path.join( 51 options.output_directory, 52 os.path.relpath(root, source_tree_root)) 53 if options.generate and not os.path.exists(target_directory): 54 os.makedirs(target_directory) 55 56 for header_spec in args: 57 if ';' in header_spec: 58 (header_filename, 59 include_before, 60 include_after) = header_spec.split(';', 2) 61 else: 62 header_filename = header_spec 63 include_before = '' 64 include_after = '' 65 if options.outputs: 66 yield os.path.join(target_directory, header_filename) 67 if options.generate: 68 with open(os.path.join(target_directory, header_filename), 'w') as f: 69 f.write(SHIM_TEMPLATE) 70 71 if options.define: 72 for define in options.define: 73 key, value = define.split('=', 1) 74 # This non-standard push_macro extension is supported 75 # by compilers we support (GCC, clang). 76 f.write('#pragma push_macro("%s")\n' % key) 77 f.write('#undef %s\n' % key) 78 f.write('#define %s %s\n' % (key, value)) 79 80 if include_before: 81 for header in include_before.split(':'): 82 f.write('#include %s\n' % header) 83 84 include_target = options.prefix + header_filename 85 if options.use_include_next: 86 f.write('#include_next <%s>\n' % include_target) 87 else: 88 f.write('#include <%s>\n' % include_target) 89 90 if include_after: 91 for header in include_after.split(':'): 92 f.write('#include %s\n' % header) 93 94 if options.define: 95 for define in options.define: 96 key, value = define.split('=', 1) 97 # This non-standard pop_macro extension is supported 98 # by compilers we support (GCC, clang). 99 f.write('#pragma pop_macro("%s")\n' % key) 100 101 102def DoMain(argv): 103 return '\n'.join(GeneratorMain(argv)) 104 105 106if __name__ == '__main__': 107 DoMain(sys.argv[1:]) 108