#!/usr/bin/python # Copyright (c) 2006-2008 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. """Script to verify a Portable Executable's dependencies. Analyzes the input portable executable (a DLL or an EXE for example), extracts its imports and confirms that its dependencies haven't changed. This is for regression testing. Returns 0 if the list matches. 1 if one or more dependencies has been removed. 2 if one or more dependencies has been added. This preempts removal result code. """ import optparse import os import subprocess import sys # The default distribution name and the environment variable that overrides it. DIST_DEFAULT = '_chromium' DIST_ENV_VAR = 'CHROMIUM_BUILD' DUMPBIN = "dumpbin.exe" class Error(Exception): def __init__(self, message): self.message = message def __str__(self): return self.message def RunSystemCommand(cmd): try: return subprocess.Popen(cmd, stdout=subprocess.PIPE).communicate()[0] except: raise Error("Failed to execute: " + cmd) def RunDumpbin(binary_file): """Runs dumpbin and parses its output. Args: binary_file: the binary to analyze Returns: a tuple of the dependencies and the delay-load dependencies The output of dumpbin that we will be parsing looks like this: -- Image has the following dependencies: foo.dll bar.dll Image has the following delay load dependencies: foobar.dll other.dll Summary -- The following parser extracts the dll names from the above format. """ cmd = DUMPBIN + " /dependents " + binary_file output = RunSystemCommand(cmd) dependents = [] delay_loaded = [] (START, DEPENDENCIES_HEADER, DEPENDENCIES, DELAY_LOAD_HEADER, DELAY_LOAD, SUMMARY_HEADER, SUMMARY) = (0, 1, 2, 3, 4, 5, 6) current_section = START # Very basic scanning. for line in output.splitlines(): line = line.strip() if len(line) > 1: if line == "Image has the following dependencies:": if current_section != START: raise Error("Internal parsing error.") current_section = DEPENDENCIES_HEADER elif line == "Image has the following delay load dependencies:": if current_section != DEPENDENCIES: raise Error("Internal parsing error.") current_section = DELAY_LOAD_HEADER elif line == "Summary": current_section = SUMMARY_HEADER elif current_section == DEPENDENCIES: # Got a dependent dependents.append(line) elif current_section == DELAY_LOAD: # Got a delay-loaded delay_loaded.append(line) else: if current_section == DEPENDENCIES_HEADER: current_section = DEPENDENCIES elif current_section == DELAY_LOAD_HEADER: current_section = DELAY_LOAD elif current_section == SUMMARY_HEADER: current_section = SUMMARY return dependents, delay_loaded def Diff(name, type, current, expected, deps_file): """ Args: name: Portable executable name being analysed. type: Type of dependency. current: List of current dependencies. expected: List of dependencies that are expected. deps_file: File name of the .deps file. Returns 0 if the lists are equal 1 if one entry in list1 is missing 2 if one entry in list2 is missing. """ # Create sets of lower-case names. set_expected = set([x.lower() for x in expected]) set_current = set([x.lower() for x in current]) only_in_expected = set_expected - set_current only_in_current = set_current - set_expected # Find difference between the sets. found_extra = 0 name = os.path.basename(name).lower() if len(only_in_expected) or len(only_in_current): print name.upper() + " DEPENDENCIES MISMATCH\n" if len(only_in_expected): # Setting found_extra to 1 causes the build to fail. In some case, some # dependencies are stripped out on optimized build; don't break anything # just for that. found_extra = 0 print "%s is no longer dependent on these %s: %s." % (name, type, ' '.join(only_in_expected)) print "Please update \"%s\"." % deps_file if len(only_in_current): found_extra = 2 string = "%s is now dependent on these %s, but shouldn't: %s." % (name, type, ' '.join(only_in_current)) stars = '*' * len(string) print "**" + stars + "**" print "* " + string + " *" print "**" + stars + "**\n" print "Please update \"%s\"." % deps_file return found_extra def VerifyDependents(pe_name, dependents, delay_loaded, list_file, verbose): """Compare the actual dependents to the expected ones.""" scope = {} try: execfile(list_file, scope) except: raise Error("Failed to load " + list_file) # The dependency files have dependencies in two section - dependents and # delay_loaded. Also various distributions of Chromium can have different # dependencies. So first we read generic dependencies ("dependents" and # "delay_loaded"). If distribution specific dependencies exist # (i.e. "dependents_google_chrome" and "delay_loaded_google_chrome") we use # those instead. distribution = DIST_DEFAULT if DIST_ENV_VAR in os.environ.keys(): distribution = os.environ[DIST_ENV_VAR].lower() expected_dependents = scope["dependents"] dist_dependents = "dependents" + distribution if dist_dependents in scope.keys(): expected_dependents = scope[dist_dependents] expected_delay_loaded = scope["delay_loaded"] dist_delay_loaded = "delay_loaded" + distribution if dist_delay_loaded in scope.keys(): expected_delay_loaded = scope[dist_delay_loaded] if verbose: print "Expected dependents:" print "\n".join(expected_dependents) print "Expected delayloaded:" print "\n".join(expected_delay_loaded) deps_result = Diff(pe_name, "dll", dependents, expected_dependents, list_file) delayed_result = Diff(pe_name, "delay loaded dll", delay_loaded, expected_delay_loaded, list_file) return max(deps_result, delayed_result) def main(options, args): # PE means portable executable. It's any .DLL, .EXE, .SYS, .AX, etc. pe_name = args[0] deps_file = args[1] dependents, delay_loaded = RunDumpbin(pe_name) if options.debug: print "Dependents:" print "\n".join(dependents) print "Delayloaded:" print "\n".join(delay_loaded) return VerifyDependents(pe_name, dependents, delay_loaded, deps_file, options.debug) if '__main__' == __name__: usage = "usage: %prog [options] input output" option_parser = optparse.OptionParser(usage = usage) option_parser.add_option("-d", "--debug", dest="debug", action="store_true", default=False, help="Display debugging information") options, args = option_parser.parse_args() if len(args) != 2: option_parser.error("Incorrect number of arguments") sys.exit(main(options, args))