"""Creates Windows and POSIX stub files for a given set of signatures.
For libraries that need to be loaded outside of the standard executable startup
path mechanism, stub files need to be generated for the wanted functions. In
Windows, this is done via "def" files and the delay load mechanism. On a POSIX
system, a set of stub functions need to be generated that dispatch to functions
found via dlsym.
This script takes a set of files, where each file is a list of C-style
signatures (one signature per line). The output is either a Windows def file,
or a header + implementation file of stubs suitable for use in a POSIX system.
This script also handles variadic functions, e.g.
void printf(const char* s, ...);
TODO(hclam): Fix the situation for variadic functions.
Stub for the above function will be generated and inside the stub function it
is translated to:
void printf(const char* s, ...) {
printf_ptr(s, (void*)arg1);
}
Only one argument from the variadic arguments is used and it will be used as
type void*.
"""
__author__ = 'ajwong@chromium.org (Albert J. Wong)'
import optparse
import os
import re
import string
import subprocess
import sys
class Error(Exception):
pass
class BadSignatureError(Error):
pass
class SubprocessError(Error):
def __init__(self, message, error_code):
Error.__init__(self)
self.message = message
self.error_code = error_code
def __str__(self):
return 'Failed with code %s: %s' % (self.message, repr(self.error_code))
SIGNATURE_REGEX = re.compile(r'(?P<return_type>.+?)'
r'(?P<name>[_a-zA-Z][_a-zA-Z0-9]+)\s*'
r'\((?P<params>.*?)\)')
INVALID_C_IDENT_CHARS = re.compile(r'[^_a-zA-Z0-9]')
FILE_TYPE_WIN_X86 = 'windows_lib'
FILE_TYPE_WIN_X64 = 'windows_lib_x64'
FILE_TYPE_POSIX_STUB = 'posix_stubs'
FILE_TYPE_WIN_DEF = 'windows_def'
STUB_FUNCTION_DEFINITION = (
"""extern %(return_type)s %(name)s(%(params)s) __attribute__((weak));
DISABLE_CFI_ICALL
%(return_type)s %(export)s %(name)s(%(params)s) {
%(return_prefix)s%(name)s_ptr(%(arg_list)s);
}""")
VARIADIC_STUB_FUNCTION_DEFINITION = (
"""extern %(return_type)s %(name)s(%(params)s) __attribute__((weak));
DISABLE_CFI_ICALL
%(return_type)s %(export)s %(name)s(%(params)s) {
va_list args___;
va_start(args___, %(last_named_arg)s);
%(return_type)s ret___ = %(name)s_ptr(%(arg_list)s, va_arg(args___, void*));
va_end(args___);
return ret___;
}""")
VOID_VARIADIC_STUB_FUNCTION_DEFINITION = (
"""extern void %(name)s(%(params)s) __attribute__((weak));
DISABLE_CFI_ICALL
void %(export)s %(name)s(%(params)s) {
va_list args___;
va_start(args___, %(last_named_arg)s);
%(name)s_ptr(%(arg_list)s, va_arg(args___, void*));
va_end(args___);
}""")
STUB_HEADER_PREAMBLE = """// This is generated file. Do not modify directly.
#ifndef %(guard_name)s
#define %(guard_name)s
#include <map>
#include <string>
#include <vector>
namespace %(namespace)s {
"""
STUB_HEADER_CLOSER = """} // namespace %(namespace)s
#endif // %(guard_name)s
"""
IMPLEMENTATION_PREAMBLE = """// This is generated file. Do not modify directly.
#include "%(header_path)s"
#include <dlfcn.h> // For dlsym, dlopen, RTLD_LAZY.
#include <cstdarg>
#include "%(macro_include)s"
#include "%(logging_include)s"
"""
UMBRELLA_ENUM_START = """// Enum and typedef for umbrella initializer.
enum StubModules {
"""
UMBRELLA_ENUM_END = """ kNumStubModules
};
"""
IMPLEMENTATION_CONTENTS_C_START = """extern "C" {
"""
IMPLEMENTATION_CONTENTS_C_END = """
} // extern "C"
"""
NAMESPACE_START = """namespace %s {
"""
NAMESPACE_END = """} // namespace %s
"""
FUNCTION_POINTER_SECTION_COMMENT = (
"""// Static pointers that will hold the location of the real function
// implementations after the module has been loaded.
""")
MODULE_INITIALIZATION_CHECK_FUNCTION = (
"""// Returns true if all stubs have been properly initialized.
bool %s() {
return %s;
}
""")
STUB_POINTER_INITIALIZER = """ const char %(name)s_name[] = "%(name)s";
%(name)s_ptr =
reinterpret_cast<%(return_type)s (*)(%(parameters)s)>(
dlsym(module, %(name)s_name));
if (!%(name)s_ptr)
LogDlerror(%(name)s_name);
"""
LOG_DLERROR = """void LogDlerror(const char* symbol) {
%s << "Couldn't load " << symbol << ", dlerror() says:\\n" << dlerror();
}
"""
MODULE_INITIALIZE_START = """// Initializes the module stubs.
void %s(void* module) {
"""
MODULE_INITIALIZE_END = """}
"""
MODULE_UNINITIALIZE_START = (
"""// Uninitialize the module stubs. Reset pointers to nullptr.
void %s() {
""")
MODULE_UNINITIALIZE_END = """}
"""
UMBRELLA_INITIALIZER_START = """namespace %s {
typedef std::map<StubModules, void*> StubHandleMap;
"""
UMBRELLA_INITIALIZER_CLEANUP_FUNCTION = (
"""static void CloseLibraries(StubHandleMap* stub_handles) {
for (StubHandleMap::const_iterator it = stub_handles->begin();
it != stub_handles->end();
++it) {
dlclose(it->second);
}
stub_handles->clear();
}
""")
UMBRELLA_INITIALIZER_INITIALIZE_FUNCTION_START = (
"""bool InitializeStubs(const StubPathMap& path_map) {
StubHandleMap opened_libraries;
for (int i = 0; i < kNumStubModules; ++i) {
StubModules cur_module = static_cast<StubModules>(i);
// If a module is missing, we fail.
StubPathMap::const_iterator it = path_map.find(cur_module);
if (it == path_map.end()) {
CloseLibraries(&opened_libraries);
return false;
}
// Otherwise, attempt to dlopen the library.
const std::vector<std::string>& paths = it->second;
bool module_opened = false;
for (std::vector<std::string>::const_iterator dso_path = paths.begin();
!module_opened && dso_path != paths.end();
++dso_path) {
void* handle = dlopen(dso_path->c_str(), RTLD_LAZY);
if (handle) {
module_opened = true;
opened_libraries[cur_module] = handle;
} else {
%(logging_function)s << "dlopen(" << dso_path->c_str() << ") failed.";
if (char *errstr = dlerror()) {
%(logging_function)s << "dlerror() says:\\n" << errstr;
} else {
%(logging_function)s << "dlerror() is nullptr";
}
}
}
if (!module_opened) {
CloseLibraries(&opened_libraries);
return false;
}
}
""")
UMBRELLA_INITIALIZER_CHECK_AND_CLEANUP = (
""" // Check that each module is initialized correctly.
// Close all previously opened libraries on failure.
if (%(conditional)s) {
%(uninitializers)s;
CloseLibraries(&opened_libraries);
return false;
}
return true;
}
""")
MODULE_FUNCTION_PROTOTYPES = """bool %(is_initialized)s();
void %(initialize)s(void* module);
void %(uninitialize)s();
"""
UMBRELLA_INITIALIZER_PROTOTYPE = (
"""typedef std::map<StubModules, std::vector<std::string>> StubPathMap;
// Umbrella initializer for all the modules in this stub file.
bool InitializeStubs(const StubPathMap& path_map);
""")
def ExtractModuleName(infile_path):
"""Infers the module name from the input file path.
The input filename is supposed to be in the form "ModuleName.sigs".
This function splits the filename from the extension on that basename of
the path and returns that as the module name.
Args:
infile_path: String holding the path to the input file.
Returns:
The module name as a string.
"""
basename = os.path.basename(infile_path)
while 1:
new_basename = os.path.splitext(basename)[0]
if basename == new_basename:
break
else:
basename = new_basename
return basename
def ParseSignatures(infile):
"""Parses function signatures in the input file.
This function parses a file of signatures into a list of dictionaries that
represent the function signatures in the input file. Each dictionary has
the following keys:
return_type: A string with the return type.
name: A string with the name of the function.
params: A list of each function parameter declaration (type + name)
The format of the input file is one C-style function signature per line, no
trailing semicolon. Empty lines are allowed. An empty line is a line that
consists purely of whitespace. Lines that begin with a # or // are considered
comment lines and are ignored.
We assume that "int foo(void)" is the same as "int foo()", which is not
true in C where "int foo()" is equivalent to "int foo(...)". Our generated
code is C++, and we do not handle varargs, so this is a case that can be
ignored for now.
Args:
infile: File object holding a text file of function signatures.
Returns:
A list of dictionaries, where each dictionary represents one function
signature.
Raises:
BadSignatureError: A line could not be parsed as a signature.
"""
signatures = []
for line in infile:
line = line.strip()
if line and line[0] != '#' and line[0:2] != '//':
m = SIGNATURE_REGEX.match(line)
if m is None:
raise BadSignatureError('Unparsable line: %s' % line)
signatures.append({
'return_type':
m.group('return_type').strip(),
'name':
m.group('name').strip(),
'params': [arg.strip() for arg in m.group('params').split(',')]
})
return signatures
def WriteWindowsDefFile(module_name, signatures, outfile):
"""Writes a Windows def file to the given output file object.
The def file format is basically a list of function names. Generation is
simple. After outputting the LIBRARY and EXPORTS lines, print out each
function name, one to a line, preceded by 2 spaces.
Args:
module_name: The name of the module we are writing a stub for.
signatures: The list of signature hashes, as produced by ParseSignatures,
to create stubs for.
outfile: File handle to populate with definitions.
"""
outfile.write('LIBRARY %s\n' % module_name)
outfile.write('EXPORTS\n')
for sig in signatures:
outfile.write(' %s\n' % sig['name'])
def QuietRun(args, filter=None, write_to=sys.stdout):
"""Invoke |args| as command via subprocess.Popen, filtering lines starting
with |filter|."""
popen = subprocess.Popen(args, stdout=subprocess.PIPE)
out, _ = popen.communicate()
for line in out.decode('utf-8').splitlines():
if not filter or not line.startswith(filter):
write_to.write(line + '\n')
return popen.returncode
def CreateWindowsLib(module_name, signatures, intermediate_dir, outdir_path,
machine):
"""Creates a Windows library file.
Calling this function will create a lib file in the outdir_path that exports
the signatures passed into the object. A temporary def file will be created
in the intermediate_dir.
Args:
module_name: The name of the module we are writing a stub for.
signatures: The list of signature hashes, as produced by ParseSignatures,
to create stubs for.
intermediate_dir: The directory where the generated .def files should go.
outdir_path: The directory where generated .lib files should go.
machine: String holding the machine type, 'X86' or 'X64'.
Raises:
SubprocessError: If invoking the Windows "lib" tool fails, this is raised
with the error code.
"""
def_file_path = os.path.join(intermediate_dir, module_name + '.def')
lib_file_path = os.path.join(outdir_path, module_name + '.lib')
outfile = open(def_file_path, 'w')
try:
WriteWindowsDefFile(module_name, signatures, outfile)
finally:
outfile.close()
ret = QuietRun([
'lib', '/nologo', '/machine:' + machine, '/def:' + def_file_path,
'/out:' + lib_file_path
],
filter=' Creating library')
if ret != 0:
raise SubprocessError(
'Failed creating %s for %s' % (lib_file_path, def_file_path), ret)
class PosixStubWriter(object):
"""Creates a file of stub functions for a library that is opened via dlopen.
Windows provides a function in their compiler known as delay loading, which
effectively generates a set of stub functions for a dynamic library that
delays loading of the dynamic library/resolution of the symbols until one of
the needed functions are accessed.
In POSIX, RTLD_LAZY does something similar with DSOs. This is the default
link mode for DSOs. However, even though the symbol is not resolved until
first usage, the DSO must be present at load time of the main binary.
To simulate the Windows delay load procedure, we need to create a set of
stub functions that allow for correct linkage of the main binary, but
dispatch to the dynamically resolved symbol when the module is initialized.
This class takes a list of function signatures, and generates a set of stub
functions plus initialization code for them.
"""
def __init__(self, module_name, export_macro, signatures, logging_function):
"""Initializes PosixStubWriter for this set of signatures and module_name.
Args:
module_name: The name of the module we are writing a stub for.
export_macro: A preprocessor macro used to annotate stub symbols with
an EXPORT marking, to control visibility.
signatures: The list of signature hashes, as produced by ParseSignatures,
to create stubs for.
logging_function: Function call that will be used for error logging.
"""
self.signatures = signatures
self.module_name = module_name
self.export_macro = export_macro
self.logging_function = logging_function
@classmethod
def CStyleIdentifier(cls, identifier):
"""Generates a C style identifier.
The module_name has all invalid identifier characters removed (anything
that's not [_a-zA-Z0-9]) and is run through string.capwords to try
and approximate camel case.
Args:
identifier: The string with the module name to turn to C-style.
Returns:
A string that can be used as part of a C identifier.
"""
return string.capwords(re.sub(INVALID_C_IDENT_CHARS, '', identifier))
@classmethod
def EnumName(cls, module_name):
"""Gets the enum name for the module.
Takes the module name and creates a suitable enum name. The module_name
is munged to be a valid C identifier then prefixed with the string
"kModule" to generate a Google style enum name.
Args:
module_name: The name of the module to generate an enum name for.
Returns:
A string with the name of the enum value representing this module.
"""
return 'kModule%s' % PosixStubWriter.CStyleIdentifier(module_name)
@classmethod
def IsInitializedName(cls, module_name):
"""Gets the name of function that checks initialization of this module.
The name is in the format IsModuleInitialized. Where "Module" is replaced
with the module name, munged to be a valid C identifier.
Args:
module_name: The name of the module to generate the function name for.
Returns:
A string with the name of the initialization check function.
"""
return 'Is%sInitialized' % PosixStubWriter.CStyleIdentifier(module_name)
@classmethod
def InitializeModuleName(cls, module_name):
"""Gets the name of the function that initializes this module.
The name is in the format InitializeModule. Where "Module" is replaced
with the module name, munged to be a valid C identifier.
Args:
module_name: The name of the module to generate the function name for.
Returns:
A string with the name of the initialization function.
"""
return 'Initialize%s' % PosixStubWriter.CStyleIdentifier(module_name)
@classmethod
def UninitializeModuleName(cls, module_name):
"""Gets the name of the function that uninitializes this module.
The name is in the format UninitializeModule. Where "Module" is replaced
with the module name, munged to be a valid C identifier.
Args:
module_name: The name of the module to generate the function name for.
Returns:
A string with the name of the uninitialization function.
"""
return 'Uninitialize%s' % PosixStubWriter.CStyleIdentifier(module_name)
@classmethod
def StubFunctionPointer(cls, signature):
"""Generates a function pointer declaration for the given signature.
Args:
signature: A signature hash, as produced by ParseSignatures,
representing the function signature.
Returns:
A string with the declaration of the function pointer for the signature.
"""
return 'static %s (*%s_ptr)(%s) = nullptr;' % (signature['return_type'],
signature['name'], ', '.join(
signature['params']))
@classmethod
def StubFunction(cls, signature):
"""Generates a stub function definition for the given signature.
The function definitions are created with __attribute__((weak)) so that
they may be overridden by a real static link or mock versions to be used
when testing.
Args:
signature: A signature hash, as produced by ParseSignatures,
representing the function signature.
Returns:
A string with the stub function definition.
"""
return_prefix = ''
if signature['return_type'] != 'void':
return_prefix = 'return '
arguments = [
re.split(r'[\*& ]', arg)[-1].strip() for arg in signature['params']
]
for i in range(0, len(arguments)):
if arguments[i].endswith('[]'):
arguments[i] = arguments[i][0:-2]
arg_list = ', '.join(arguments)
if arg_list == 'void':
arg_list = ''
if arg_list != '' and len(arguments) > 1 and arguments[-1] == '...':
if return_prefix != '':
return VARIADIC_STUB_FUNCTION_DEFINITION % {
'return_type': signature['return_type'],
'name': signature['name'],
'params': ', '.join(signature['params']),
'arg_list': ', '.join(arguments[0:-1]),
'last_named_arg': arguments[-2],
'export': signature.get('export', '')
}
else:
return VOID_VARIADIC_STUB_FUNCTION_DEFINITION % {
'name': signature['name'],
'params': ', '.join(signature['params']),
'arg_list': ', '.join(arguments[0:-1]),
'last_named_arg': arguments[-2],
'export': signature.get('export', '')
}
else:
return STUB_FUNCTION_DEFINITION % {
'return_type': signature['return_type'],
'name': signature['name'],
'params': ', '.join(signature['params']),
'return_prefix': return_prefix,
'arg_list': arg_list,
'export': signature.get('export', '')
}
@classmethod
def WriteImplementationPreamble(cls, header_path, outfile, logging_include,
macro_include):
"""Write the necessary includes for the implementation file.
Args:
header_path: The path to the header file.
outfile: The file handle to populate.
"""
outfile.write(
IMPLEMENTATION_PREAMBLE % {
'header_path': header_path,
'logging_include': logging_include,
'macro_include': macro_include,
})
@classmethod
def WriteUmbrellaInitializer(cls, module_names, namespace, outfile,
logging_function):
"""Writes a single function that will open + initialize each module.
This intializer will take in an stl map of that lists the correct
dlopen target for each module. The map type is
std::map<enum StubModules, vector<std::string>> which matches one module
to a list of paths to try in dlopen.
This function is an all-or-nothing function. If any module fails to load,
all other modules are dlclosed, and the function returns. Though it is
not enforced, this function should only be called once.
Args:
module_names: A list with the names of the modules in this stub file.
namespace: The namespace these functions should be in.
outfile: The file handle to populate with pointer definitions.
"""
outfile.write(UMBRELLA_INITIALIZER_START % namespace)
outfile.write(UMBRELLA_INITIALIZER_CLEANUP_FUNCTION)
outfile.write(UMBRELLA_INITIALIZER_INITIALIZE_FUNCTION_START %
{'logging_function': logging_function})
outfile.write(
'\n // Initialize each module if we have not already failed.\n')
for module in module_names:
outfile.write(' %s(opened_libraries[%s]);\n' %
(PosixStubWriter.InitializeModuleName(module),
PosixStubWriter.EnumName(module)))
outfile.write('\n')
initializer_checks = [
'!%s()' % PosixStubWriter.IsInitializedName(name)
for name in module_names
]
uninitializers = [
'%s()' % PosixStubWriter.UninitializeModuleName(name)
for name in module_names
]
outfile.write(
UMBRELLA_INITIALIZER_CHECK_AND_CLEANUP % {
'conditional': ' ||\n '.join(initializer_checks),
'uninitializers': ';\n '.join(uninitializers)
})
outfile.write('\n} // namespace %s\n' % namespace)
@classmethod
def WriteHeaderContents(cls, module_names, namespace, header_guard, outfile):
"""Writes a header file for the stub file generated for module_names.
The header file exposes the following:
1) An enum, StubModules, listing with an entry for each enum.
2) A typedef for a StubPathMap allowing for specification of paths to
search for each module.
3) The IsInitialized/Initialize/Uninitialize functions for each module.
4) An umbrella initialize function for all modules.
Args:
module_names: A list with the names of each module in this stub file.
namespace: The namespace these functions should be in.
header_guard: The macro to use as our header guard.
outfile: The output handle to populate.
"""
outfile.write(STUB_HEADER_PREAMBLE % {
'guard_name': header_guard,
'namespace': namespace
})
outfile.write('// Individual module initializer functions.\n')
for name in module_names:
outfile.write(
MODULE_FUNCTION_PROTOTYPES % {
'is_initialized': PosixStubWriter.IsInitializedName(name),
'initialize': PosixStubWriter.InitializeModuleName(name),
'uninitialize': PosixStubWriter.UninitializeModuleName(name)
})
outfile.write(UMBRELLA_ENUM_START)
outfile.write(' %s = 0,\n' % PosixStubWriter.EnumName(module_names[0]))
for name in module_names[1:]:
outfile.write(' %s,\n' % PosixStubWriter.EnumName(name))
outfile.write(UMBRELLA_ENUM_END)
outfile.write(UMBRELLA_INITIALIZER_PROTOTYPE)
outfile.write(STUB_HEADER_CLOSER % {
'namespace': namespace,
'guard_name': header_guard
})
def WriteImplementationContents(self, namespace, outfile):
"""Given a file handle, write out the stub definitions for this module.
Args:
namespace: The namespace these functions should be in.
outfile: The file handle to populate.
"""
outfile.write(IMPLEMENTATION_CONTENTS_C_START)
self.WriteFunctionPointers(outfile)
self.WriteStubFunctions(outfile)
outfile.write(IMPLEMENTATION_CONTENTS_C_END)
outfile.write(NAMESPACE_START % namespace)
self.WriteModuleInitializeFunctions(outfile)
outfile.write(NAMESPACE_END % namespace)
def WriteFunctionPointers(self, outfile):
"""Write the function pointer declarations needed by the stubs.
We need function pointers to hold the actual location of the function
implementation returned by dlsym. This function outputs a pointer
definition for each signature in the module.
Pointers will be named with the following pattern "FuntionName_ptr".
Args:
outfile: The file handle to populate with pointer definitions.
"""
outfile.write(FUNCTION_POINTER_SECTION_COMMENT)
for sig in self.signatures:
outfile.write('%s\n' % PosixStubWriter.StubFunctionPointer(sig))
outfile.write('\n')
def WriteStubFunctions(self, outfile):
"""Write the function stubs to handle dispatching to real implementations.
Functions that have a return type other than void will look as follows:
ReturnType FunctionName(A a) {
return FunctionName_ptr(a);
}
Functions with a return type of void will look as follows:
void FunctionName(A a) {
FunctionName_ptr(a);
}
Args:
outfile: The file handle to populate.
"""
outfile.write('// Stubs that dispatch to the real implementations.\n')
for sig in self.signatures:
sig['export'] = self.export_macro
outfile.write('%s\n' % PosixStubWriter.StubFunction(sig))
def WriteModuleInitializeFunctions(self, outfile):
"""Write functions to initialize/query initlialization of the module.
This creates 2 functions IsModuleInitialized and InitializeModule where
"Module" is replaced with the module name, first letter capitalized.
The InitializeModule function takes a handle that is retrieved from dlopen
and attempts to assign each function pointer above via dlsym.
The IsModuleInitialized returns true if none of the required functions
pointers are nullptr.
Args:
outfile: The file handle to populate.
"""
ptr_names = ['%s_ptr' % sig['name'] for sig in self.signatures]
initialization_conditional = ' &&\n '.join(ptr_names)
outfile.write(MODULE_INITIALIZATION_CHECK_FUNCTION %
(PosixStubWriter.IsInitializedName(
self.module_name), initialization_conditional))
outfile.write(MODULE_INITIALIZE_START %
PosixStubWriter.InitializeModuleName(self.module_name))
for sig in self.signatures:
outfile.write(
STUB_POINTER_INITIALIZER % {
'name': sig['name'],
'return_type': sig['return_type'],
'parameters': ', '.join(sig['params']),
'logging_function': self.logging_function
})
outfile.write(MODULE_INITIALIZE_END)
outfile.write(MODULE_UNINITIALIZE_START %
PosixStubWriter.UninitializeModuleName(self.module_name))
for sig in self.signatures:
outfile.write(' %s_ptr = nullptr;\n' % sig['name'])
outfile.write(MODULE_UNINITIALIZE_END)
def CreateOptionParser():
"""Creates an OptionParser for the configuration options of script.
Returns:
A OptionParser object.
"""
parser = optparse.OptionParser(usage='usage: %prog [options] input')
parser.add_option('-o',
'--output',
dest='out_dir',
default=None,
help='Output location.')
parser.add_option(
'-i',
'--intermediate_dir',
dest='intermediate_dir',
default=None,
help=('Location of intermediate files. Ignored for %s type' %
FILE_TYPE_WIN_DEF))
parser.add_option('-t',
'--type',
dest='type',
default=None,
help=('Type of file. Valid types are "%s" or "%s" or "%s" '
'or "%s"' % (FILE_TYPE_POSIX_STUB, FILE_TYPE_WIN_X86,
FILE_TYPE_WIN_X64, FILE_TYPE_WIN_DEF)))
parser.add_option('-s',
'--stubfile_name',
dest='stubfile_name',
default=None,
help=('Name of posix_stubs output file. Only valid with '
'%s type.' % FILE_TYPE_POSIX_STUB))
parser.add_option('-p',
'--path_from_source',
dest='path_from_source',
default=None,
help=('The relative path from the project root that the '
'generated file should consider itself part of (eg. '
'third_party/ffmpeg). This is used to generate the '
'header guard and namespace for our initializer '
'functions and does NOT affect the physical output '
'location of the file like -o does. Ignored for '
'%s and %s types.' %
(FILE_TYPE_WIN_X86, FILE_TYPE_WIN_X64)))
parser.add_option('-e',
'--extra_stub_header',
dest='extra_stub_header',
default=None,
help=('File to insert after the system includes in the '
'generated stub implementation file. Ignored for '
'%s and %s types.' %
(FILE_TYPE_WIN_X86, FILE_TYPE_WIN_X64)))
parser.add_option('-m',
'--module_name',
dest='module_name',
default=None,
help=('Name of output DLL or LIB for DEF creation using '
'%s type.' % FILE_TYPE_WIN_DEF))
parser.add_option('-x',
'--export_macro',
dest='export_macro',
default='',
help=('A macro to place between the return type and '
'function name, e.g. MODULE_EXPORT, to control the '
'visibility of the stub functions.'))
parser.add_option('-l',
'--logging-function',
dest='logging_function',
default='VLOG(1)',
help=('Function call that will be used for error logging.'))
parser.add_option('-n',
'--logging-include',
dest='logging_include',
default='base/logging.h',
help=('Header file where the logging function is defined.'))
parser.add_option('--macro-include',
dest='macro_include',
default='base/compiler_specific.h',
help=('Header file where DISABLE_CFI_ICALL is defined.'))
return parser
def ParseOptions():
"""Parses the options and terminates program if they are not sane.
Returns:
The pair (optparse.OptionValues, [string]), that is the output of
a successful call to parser.parse_args().
"""
parser = CreateOptionParser()
options, args = parser.parse_args()
if not args:
parser.error('No inputs specified')
if options.out_dir is None:
parser.error('Output location not specified')
if (options.type not in [
FILE_TYPE_WIN_X86, FILE_TYPE_WIN_X64, FILE_TYPE_POSIX_STUB,
FILE_TYPE_WIN_DEF
]):
parser.error('Invalid output file type: %s' % options.type)
if options.type == FILE_TYPE_POSIX_STUB:
if options.stubfile_name is None:
parser.error('Output file name needed for %s' % FILE_TYPE_POSIX_STUB)
if options.path_from_source is None:
parser.error('Path from source needed for %s' % FILE_TYPE_POSIX_STUB)
if options.type == FILE_TYPE_WIN_DEF:
if options.module_name is None:
parser.error('Module name needed for %s' % FILE_TYPE_WIN_DEF)
return options, args
def EnsureDirExists(dir):
"""Creates a directory. Does not use the more obvious 'if not exists: create'
to avoid race with other invocations of the same code, which will error out
on makedirs if another invocation has succeeded in creating the directory
since the existence check."""
try:
os.makedirs(dir)
except:
if not os.path.isdir(dir):
raise
def CreateOutputDirectories(options):
"""Creates the intermediate and final output directories.
Given the parsed options, create the intermediate and final output
directories if they do not exist. Returns the paths to both directories
as a pair.
Args:
options: An OptionParser.OptionValues object with the parsed options.
Returns:
The pair (out_dir, intermediate_dir), both of which are strings.
"""
out_dir = os.path.normpath(options.out_dir)
intermediate_dir = os.path.normpath(options.intermediate_dir)
if intermediate_dir is None:
intermediate_dir = out_dir
EnsureDirExists(out_dir)
EnsureDirExists(intermediate_dir)
return out_dir, intermediate_dir
def CreateWindowsLibForSigFiles(sig_files, out_dir, intermediate_dir, machine,
export_macro):
"""For each signature file, create a Windows lib.
Args:
sig_files: Array of strings with the paths to each signature file.
out_dir: String holding path to directory where the generated libs go.
intermediate_dir: String holding path to directory generated intermediate
artifacts.
machine: String holding the machine type, 'X86' or 'X64'.
export_macro: A preprocessor macro used to annotate stub symbols with
an EXPORT marking, to control visibility.
"""
for input_path in sig_files:
infile = open(input_path, 'r')
try:
signatures = ParseSignatures(infile)
module_name = ExtractModuleName(os.path.basename(input_path))
for sig in signatures:
sig['export'] = export_macro
CreateWindowsLib(module_name, signatures, intermediate_dir, out_dir,
machine)
finally:
infile.close()
def CreateWindowsDefForSigFiles(sig_files, out_dir, module_name):
"""For all signature files, create a single Windows def file.
Args:
sig_files: Array of strings with the paths to each signature file.
out_dir: String holding path to directory where the generated def goes.
module_name: Name of the output DLL or LIB which will link in the def file.
"""
signatures = []
for input_path in sig_files:
infile = open(input_path, 'r')
try:
signatures += ParseSignatures(infile)
finally:
infile.close()
def_file_path = os.path.join(
out_dir,
os.path.splitext(os.path.basename(module_name))[0] + '.def')
outfile = open(def_file_path, 'w')
try:
WriteWindowsDefFile(module_name, signatures, outfile)
finally:
outfile.close()
def CreatePosixStubsForSigFiles(sig_files, stub_name, out_dir, intermediate_dir,
path_from_source, extra_stub_header,
export_macro, logging_function, logging_include,
macro_include):
"""Create a POSIX stub library with a module for each signature file.
Args:
sig_files: Array of strings with the paths to each signature file.
stub_name: String with the basename of the generated stub file.
out_dir: String holding path to directory for the .h files.
intermediate_dir: String holding path to directory for the .cc files.
path_from_source: String with relative path of generated files from the
project root.
extra_stub_header: String with path to file of extra lines to insert
into the generated header for the stub library.
export_macro: A preprocessor macro used to annotate stub symbols with
an EXPORT marking, to control visibility.
logging_function: Function call that will be used for error logging.
logging_include: Header file where the logging function is defined.
header_include: Header file where the logging function is defined.
"""
header_base_name = stub_name + '.h'
header_path = os.path.join(out_dir, header_base_name)
impl_path = os.path.join(intermediate_dir, stub_name + '.cc')
module_names = [ExtractModuleName(path) for path in sig_files]
namespace = path_from_source.replace('/', '_').lower()
header_guard = 'GEN_%s_%s_H_' % (namespace.upper(), stub_name.upper())
header_include_path = os.path.join(path_from_source, header_base_name)
impl_file = open(impl_path, 'w')
try:
PosixStubWriter.WriteImplementationPreamble(header_include_path, impl_file,
logging_include, macro_include)
if extra_stub_header is not None:
extra_header_file = open(extra_stub_header, 'r')
try:
impl_file.write('\n')
for line in extra_header_file:
impl_file.write(line)
impl_file.write('\n')
finally:
extra_header_file.close()
impl_file.write(NAMESPACE_START % '')
impl_file.write(LOG_DLERROR % logging_function)
impl_file.write(NAMESPACE_END % '')
for input_path in sig_files:
name = ExtractModuleName(input_path)
infile = open(input_path, 'r')
try:
signatures = ParseSignatures(infile)
finally:
infile.close()
writer = PosixStubWriter(name, export_macro, signatures, logging_function)
writer.WriteImplementationContents(namespace, impl_file)
PosixStubWriter.WriteUmbrellaInitializer(module_names, namespace, impl_file,
logging_function)
finally:
impl_file.close()
header_file = open(header_path, 'w')
try:
PosixStubWriter.WriteHeaderContents(module_names, namespace, header_guard,
header_file)
finally:
header_file.close()
def main():
options, args = ParseOptions()
out_dir, intermediate_dir = CreateOutputDirectories(options)
if options.type == FILE_TYPE_WIN_X86:
CreateWindowsLibForSigFiles(args, out_dir, intermediate_dir, 'X86',
options.export_macro)
elif options.type == FILE_TYPE_WIN_X64:
CreateWindowsLibForSigFiles(args, out_dir, intermediate_dir, 'X64',
options.export_macro)
elif options.type == FILE_TYPE_POSIX_STUB:
CreatePosixStubsForSigFiles(args, options.stubfile_name, out_dir,
intermediate_dir, options.path_from_source,
options.extra_stub_header, options.export_macro,
options.logging_function,
options.logging_include, options.macro_include)
elif options.type == FILE_TYPE_WIN_DEF:
CreateWindowsDefForSigFiles(args, out_dir, options.module_name)
if __name__ == '__main__':
main()
