diff options
Diffstat (limited to 'Lib/dis.py')
| -rw-r--r-- | Lib/dis.py | 56 |
1 files changed, 49 insertions, 7 deletions
@@ -203,6 +203,9 @@ _Instruction.offset.__doc__ = "Start index of operation within bytecode sequence _Instruction.starts_line.__doc__ = "Line started by this opcode (if any), otherwise None" _Instruction.is_jump_target.__doc__ = "True if other code jumps to here, otherwise False" +_ExceptionTableEntry = collections.namedtuple("_ExceptionTableEntry", + "start end target depth lasti") + _OPNAME_WIDTH = 20 _OPARG_WIDTH = 5 @@ -308,8 +311,33 @@ def _get_name_info(name_index, name_list): return argval, argrepr +def parse_varint(iterator): + b = next(iterator) + val = b & 63 + while b&64: + val <<= 6 + b = next(iterator) + val |= b&63 + return val + +def parse_exception_table(code): + iterator = iter(code.co_exceptiontable) + entries = [] + try: + while True: + start = parse_varint(iterator)*2 + length = parse_varint(iterator)*2 + end = start + length + target = parse_varint(iterator)*2 + dl = parse_varint(iterator) + depth = dl >> 1 + lasti = bool(dl&1) + entries.append(_ExceptionTableEntry(start, end, target, depth, lasti)) + except StopIteration: + return entries + def _get_instructions_bytes(code, varnames=None, names=None, constants=None, - cells=None, linestarts=None, line_offset=0): + cells=None, linestarts=None, line_offset=0, exception_entries=()): """Iterate over the instructions in a bytecode string. Generates a sequence of Instruction namedtuples giving the details of each @@ -318,7 +346,10 @@ def _get_instructions_bytes(code, varnames=None, names=None, constants=None, arguments. """ - labels = findlabels(code) + labels = set(findlabels(code)) + for start, end, target, _, _ in exception_entries: + for i in range(start, end): + labels.add(target) starts_line = None for offset, op, arg in _unpack_opargs(code): if linestarts is not None: @@ -369,8 +400,10 @@ def disassemble(co, lasti=-1, *, file=None): """Disassemble a code object.""" cell_names = co.co_cellvars + co.co_freevars linestarts = dict(findlinestarts(co)) + exception_entries = parse_exception_table(co) _disassemble_bytes(co.co_code, lasti, co.co_varnames, co.co_names, - co.co_consts, cell_names, linestarts, file=file) + co.co_consts, cell_names, linestarts, file=file, + exception_entries=exception_entries) def _disassemble_recursive(co, *, file=None, depth=None): disassemble(co, file=file) @@ -385,7 +418,7 @@ def _disassemble_recursive(co, *, file=None, depth=None): def _disassemble_bytes(code, lasti=-1, varnames=None, names=None, constants=None, cells=None, linestarts=None, - *, file=None, line_offset=0): + *, file=None, line_offset=0, exception_entries=()): # Omit the line number column entirely if we have no line number info show_lineno = bool(linestarts) if show_lineno: @@ -403,7 +436,7 @@ def _disassemble_bytes(code, lasti=-1, varnames=None, names=None, offset_width = 4 for instr in _get_instructions_bytes(code, varnames, names, constants, cells, linestarts, - line_offset=line_offset): + line_offset=line_offset, exception_entries=exception_entries): new_source_line = (show_lineno and instr.starts_line is not None and instr.offset > 0) @@ -412,6 +445,12 @@ def _disassemble_bytes(code, lasti=-1, varnames=None, names=None, is_current_instr = instr.offset == lasti print(instr._disassemble(lineno_width, is_current_instr, offset_width), file=file) + if exception_entries: + print("ExceptionTable:", file=file) + for entry in exception_entries: + lasti = " lasti" if entry.lasti else "" + end = entry.end-2 + print(f" {entry.start} to {end} -> {entry.target} [{entry.depth}]{lasti}", file=file) def _disassemble_str(source, **kwargs): """Compile the source string, then disassemble the code object.""" @@ -482,13 +521,15 @@ class Bytecode: self._linestarts = dict(findlinestarts(co)) self._original_object = x self.current_offset = current_offset + self.exception_entries = parse_exception_table(co) def __iter__(self): co = self.codeobj return _get_instructions_bytes(co.co_code, co.co_varnames, co.co_names, co.co_consts, self._cell_names, self._linestarts, - line_offset=self._line_offset) + line_offset=self._line_offset, + exception_entries=self.exception_entries) def __repr__(self): return "{}({!r})".format(self.__class__.__name__, @@ -519,7 +560,8 @@ class Bytecode: linestarts=self._linestarts, line_offset=self._line_offset, file=output, - lasti=offset) + lasti=offset, + exception_entries=self.exception_entries) return output.getvalue() |