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 """Creates an import library from an import description file.""" 7 import ast 8 import logging 9 import optparse 10 import os 11 import os.path 12 import shutil 13 import subprocess 14 import sys 15 import tempfile 16 17 18 _USAGE = """\ 19 Usage: %prog [options] [imports-file] 20 21 Creates an import library from imports-file. 22 23 Note: this script uses the microsoft assembler (ml.exe) and the library tool 24 (lib.exe), both of which must be in path. 25 """ 26 27 28 _ASM_STUB_HEADER = """\ 29 ; This file is autogenerated by create_importlib_win.py, do not edit. 30 .386 31 .MODEL FLAT, C 32 .CODE 33 34 ; Stubs to provide mangled names to lib.exe for the 35 ; correct generation of import libs. 36 """ 37 38 39 _DEF_STUB_HEADER = """\ 40 ; This file is autogenerated by create_importlib_win.py, do not edit. 41 42 ; Export declarations for generating import libs. 43 """ 44 45 46 _LOGGER = logging.getLogger() 47 48 49 50 class _Error(Exception): 51 pass 52 53 54 class _ImportLibraryGenerator(object): 55 def __init__(self, temp_dir): 56 self._temp_dir = temp_dir 57 58 def _Shell(self, cmd, **kw): 59 ret = subprocess.call(cmd, **kw) 60 _LOGGER.info('Running "%s" returned %d.', cmd, ret) 61 if ret != 0: 62 raise _Error('Command "%s" returned %d.' % (cmd, ret)) 63 64 def _ReadImportsFile(self, imports_file): 65 # Slurp the imports file. 66 return ast.literal_eval(open(imports_file).read()) 67 68 def _WriteStubsFile(self, import_names, output_file): 69 output_file.write(_ASM_STUB_HEADER) 70 71 for name in import_names: 72 output_file.write('%s PROC\n' % name) 73 output_file.write('%s ENDP\n' % name) 74 75 output_file.write('END\n') 76 77 def _WriteDefFile(self, dll_name, import_names, output_file): 78 output_file.write(_DEF_STUB_HEADER) 79 output_file.write('NAME %s\n' % dll_name) 80 output_file.write('EXPORTS\n') 81 for name in import_names: 82 name = name.split('@')[0] 83 output_file.write(' %s\n' % name) 84 85 def _CreateObj(self, dll_name, imports): 86 """Writes an assembly file containing empty declarations. 87 88 For each imported function of the form: 89 90 AddClipboardFormatListener@4 PROC 91 AddClipboardFormatListener@4 ENDP 92 93 The resulting object file is then supplied to lib.exe with a .def file 94 declaring the corresponding non-adorned exports as they appear on the 95 exporting DLL, e.g. 96 97 EXPORTS 98 AddClipboardFormatListener 99 100 In combination, the .def file and the .obj file cause lib.exe to generate 101 an x86 import lib with public symbols named like 102 "__imp__AddClipboardFormatListener@4", binding to exports named like 103 "AddClipboardFormatListener". 104 105 All of this is perpetrated in a temporary directory, as the intermediate 106 artifacts are quick and easy to produce, and of no interest to anyone 107 after the fact.""" 108 109 # Create an .asm file to provide stdcall-like stub names to lib.exe. 110 asm_name = dll_name + '.asm' 111 _LOGGER.info('Writing asm file "%s".', asm_name) 112 with open(os.path.join(self._temp_dir, asm_name), 'wb') as stubs_file: 113 self._WriteStubsFile(imports, stubs_file) 114 115 # Invoke on the assembler to compile it to .obj. 116 obj_name = dll_name + '.obj' 117 cmdline = ['ml.exe', '/nologo', '/c', asm_name, '/Fo', obj_name] 118 self._Shell(cmdline, cwd=self._temp_dir, stdout=open(os.devnull)) 119 120 return obj_name 121 122 def _CreateImportLib(self, dll_name, imports, architecture, output_file): 123 """Creates an import lib binding imports to dll_name for architecture. 124 125 On success, writes the import library to output file. 126 """ 127 obj_file = None 128 129 # For x86 architecture we have to provide an object file for correct 130 # name mangling between the import stubs and the exported functions. 131 if architecture == 'x86': 132 obj_file = self._CreateObj(dll_name, imports) 133 134 # Create the corresponding .def file. This file has the non stdcall-adorned 135 # names, as exported by the destination DLL. 136 def_name = dll_name + '.def' 137 _LOGGER.info('Writing def file "%s".', def_name) 138 with open(os.path.join(self._temp_dir, def_name), 'wb') as def_file: 139 self._WriteDefFile(dll_name, imports, def_file) 140 141 # Invoke on lib.exe to create the import library. 142 # We generate everything into the temporary directory, as the .exp export 143 # files will be generated at the same path as the import library, and we 144 # don't want those files potentially gunking the works. 145 dll_base_name, ext = os.path.splitext(dll_name) 146 lib_name = dll_base_name + '.lib' 147 cmdline = ['lib.exe', 148 '/machine:%s' % architecture, 149 '/def:%s' % def_name, 150 '/out:%s' % lib_name] 151 if obj_file: 152 cmdline.append(obj_file) 153 154 self._Shell(cmdline, cwd=self._temp_dir, stdout=open(os.devnull)) 155 156 # Copy the .lib file to the output directory. 157 shutil.copyfile(os.path.join(self._temp_dir, lib_name), output_file) 158 _LOGGER.info('Created "%s".', output_file) 159 160 def CreateImportLib(self, imports_file, output_file): 161 # Read the imports file. 162 imports = self._ReadImportsFile(imports_file) 163 164 # Creates the requested import library in the output directory. 165 self._CreateImportLib(imports['dll_name'], 166 imports['imports'], 167 imports.get('architecture', 'x86'), 168 output_file) 169 170 171 def main(): 172 parser = optparse.OptionParser(usage=_USAGE) 173 parser.add_option('-o', '--output-file', 174 help='Specifies the output file path.') 175 parser.add_option('-k', '--keep-temp-dir', 176 action='store_true', 177 help='Keep the temporary directory.') 178 parser.add_option('-v', '--verbose', 179 action='store_true', 180 help='Verbose logging.') 181 182 options, args = parser.parse_args() 183 184 if len(args) != 1: 185 parser.error('You must provide an imports file.') 186 187 if not options.output_file: 188 parser.error('You must provide an output file.') 189 190 options.output_file = os.path.abspath(options.output_file) 191 192 if options.verbose: 193 logging.basicConfig(level=logging.INFO) 194 else: 195 logging.basicConfig(level=logging.WARN) 196 197 198 temp_dir = tempfile.mkdtemp() 199 _LOGGER.info('Created temporary directory "%s."', temp_dir) 200 try: 201 # Create a generator and create the import lib. 202 generator = _ImportLibraryGenerator(temp_dir) 203 204 ret = generator.CreateImportLib(args[0], options.output_file) 205 except Exception, e: 206 _LOGGER.exception('Failed to create import lib.') 207 ret = 1 208 finally: 209 if not options.keep_temp_dir: 210 shutil.rmtree(temp_dir) 211 _LOGGER.info('Deleted temporary directory "%s."', temp_dir) 212 213 return ret 214 215 216 if __name__ == '__main__': 217 sys.exit(main()) 218
