blob: 1cdc47659fc0f1c6a2d02584abcce0ee5fb5dd70 [file] [log] [blame]
""" Wicked hack to get .pyc files to do bytecode tracing instead of
line tracing.
"""
import marshal, new, opcode, sys, types
from lnotab import lnotab_numbers, lnotab_string
class PycFile:
def read(self, f):
if isinstance(f, basestring):
f = open(f, "rb")
self.magic = f.read(4)
self.modtime = f.read(4)
self.code = marshal.load(f)
def write(self, f):
if isinstance(f, basestring):
f = open(f, "wb")
f.write(self.magic)
f.write(self.modtime)
marshal.dump(self.code, f)
def hack_line_numbers(self):
self.code = hack_line_numbers(self.code)
def hack_line_numbers(code):
""" Replace a code object's line number information to claim that every
byte of the bytecode is a new source line. Returns a new code
object. Also recurses to hack the line numbers in nested code objects.
"""
# Create a new lnotab table. Each opcode is claimed to be at
# 1000*lineno + (opcode number within line), so for example, the opcodes on
# source line 12 will be given new line numbers 12000, 12001, 12002, etc.
old_num = list(lnotab_numbers(code.co_lnotab, code.co_firstlineno))
n_bytes = len(code.co_code)
new_num = []
line = 0
opnum_in_line = 0
i_byte = 0
while i_byte < n_bytes:
if old_num and i_byte == old_num[0][0]:
line = old_num.pop(0)[1]
opnum_in_line = 0
new_num.append((i_byte, 100000000 + 1000*line + opnum_in_line))
if ord(code.co_code[i_byte]) >= opcode.HAVE_ARGUMENT:
i_byte += 3
else:
i_byte += 1
opnum_in_line += 1
# new_num is a list of pairs, (byteoff, lineoff). Turn it into an lnotab.
new_firstlineno = new_num[0][1]-1
new_lnotab = lnotab_string(new_num, new_firstlineno)
# Recurse into code constants in this code object.
new_consts = []
for const in code.co_consts:
if type(const) == types.CodeType:
new_consts.append(hack_line_numbers(const))
else:
new_consts.append(const)
# Create a new code object, just like the old one, except with new
# line numbers.
new_code = new.code(
code.co_argcount, code.co_nlocals, code.co_stacksize, code.co_flags,
code.co_code, tuple(new_consts), code.co_names, code.co_varnames,
code.co_filename, code.co_name, new_firstlineno, new_lnotab
)
return new_code
def hack_file(f):
pyc = PycFile()
pyc.read(f)
pyc.hack_line_numbers()
pyc.write(f)
if __name__ == '__main__':
hack_file(sys.argv[1])