"""Routine to "compile" a .py file to a .pyc (or .pyo) file.
This module has intimate knowledge of the format of .pyc files.
"""
import builtins
import imp
import marshal
import os
import re
import sys
import traceback
MAGIC = imp.get_magic()
__all__ = ["compile", "main", "PyCompileError"]
class PyCompileError(Exception):
"""Exception raised when an error occurs while attempting to
compile the file.
To raise this exception, use
raise PyCompileError(exc_type,exc_value,file[,msg])
where
exc_type: exception type to be used in error message
type name can be accesses as class variable
'exc_type_name'
exc_value: exception value to be used in error message
can be accesses as class variable 'exc_value'
file: name of file being compiled to be used in error message
can be accesses as class variable 'file'
msg: string message to be written as error message
If no value is given, a default exception message will be given,
consistent with 'standard' py_compile output.
message (or default) can be accesses as class variable 'msg'
"""
def __init__(self, exc_type, exc_value, file, msg=''):
exc_type_name = exc_type.__name__
if exc_type is SyntaxError:
tbtext = ''.join(traceback.format_exception_only(exc_type, exc_value))
errmsg = tbtext.replace('File "<string>"', 'File "%s"' % file)
else:
errmsg = "Sorry: %s: %s" % (exc_type_name,exc_value)
Exception.__init__(self,msg or errmsg,exc_type_name,exc_value,file)
self.exc_type_name = exc_type_name
self.exc_value = exc_value
self.file = file
self.msg = msg or errmsg
def __str__(self):
return self.msg
# Define an internal helper according to the platform
if os.name == "mac":
import MacOS
def set_creator_type(file):
MacOS.SetCreatorAndType(file, 'Pyth', 'PYC ')
else:
def set_creator_type(file):
pass
def wr_long(f, x):
"""Internal; write a 32-bit int to a file in little-endian order."""
f.write(bytes([x & 0xff,
(x >> 8) & 0xff,
(x >> 16) & 0xff,
(x >> 24) & 0xff]))
def read_encoding(file, default):
"""Read the first two lines of the file looking for coding: xyzzy."""
f = open(file, "rb")
try:
for i in range(2):
line = f.readline()
if not line:
break
m = re.match(br".*\bcoding:\s*(\S+)\b", line)
if m:
return m.group(1).decode("ascii")
return default
finally:
f.close()
def compile(file, cfile=None, dfile=None, doraise=False):
"""Byte-compile one Python source file to Python bytecode.
Arguments:
file: source filename
cfile: target filename; defaults to source with 'c' or 'o' appended
('c' normally, 'o' in optimizing mode, giving .pyc or .pyo)
dfile: purported filename; defaults to source (this is the filename
that will show up in error messages)
doraise: flag indicating whether or not an exception should be
raised when a compile error is found. If an exception
occurs and this flag is set to False, a string
indicating the nature of the exception will be printed,
and the function will return to the caller. If an
exception occurs and this flag is set to True, a
PyCompileError exception will be raised.
Note that it isn't necessary to byte-compile Python modules for
execution efficiency -- Python itself byte-compiles a module when
it is loaded, and if it can, writes out the bytecode to the
corresponding .pyc (or .pyo) file.
However, if a Python installation is shared between users, it is a
good idea to byte-compile all modules upon installation, since
other users may not be able to write in the source directories,
and thus they won't be able to write the .pyc/.pyo file, and then
they would be byte-compiling every module each time it is loaded.
This can slow down program start-up considerably.
See compileall.py for a script/module that uses this module to
byte-compile all installed files (or all files in selected
directories).
"""
encoding = read_encoding(file, "utf-8")
f = open(file, 'U', encoding=encoding)
try:
timestamp = int(os.fstat(f.fileno()).st_mtime)
except AttributeError:
timestamp = int(os.stat(file).st_mtime)
codestring = f.read()
f.close()
if codestring and codestring[-1] != '\n':
codestring = codestring + '\n'
try:
codeobject = builtins.compile(codestring, dfile or file,'exec')
except Exception as err:
py_exc = PyCompileError(err.__class__, err, dfile or file)
if doraise:
raise py_exc
else:
sys.stderr.write(py_exc.msg + '\n')
return
if cfile is None:
cfile = file + (__debug__ and 'c' or 'o')
fc = open(cfile, 'wb')
fc.write(b'\0\0\0\0')
wr_long(fc, timestamp)
marshal.dump(codeobject, fc)
fc.flush()
fc.seek(0, 0)
fc.write(MAGIC)
fc.close()
set_creator_type(cfile)
def main(args=None):
"""Compile several source files.
The files named in 'args' (or on the command line, if 'args' is
not specified) are compiled and the resulting bytecode is cached
in the normal manner. This function does not search a directory
structure to locate source files; it only compiles files named
explicitly.
"""
if args is None:
args = sys.argv[1:]
rv = 0
for filename in args:
try:
compile(filename, doraise=True)
except PyCompileError as err:
# return value to indicate at least one failure
rv = 1
sys.stderr.write(err.msg)
return rv
if __name__ == "__main__":
sys.exit(main())
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