Turn the bytecode printer into a Visitor-ish class.

This is so we can analyze bytecode in other ways.

Also fork dis.disassemble() into inspect_pyc.py.  Added indentation
support in less hacky way.  It's also needed to actually get the
bytecode values, e.g. to make a histogram of bytecodes.

opy/misc/inspect_pyc.py

@@ -19,9 +19,8 @@
tools/dumppyc.py, which came with the 'compiler2' package.
"""

import dis, marshal, struct, sys, time, types
import cStringIO, dis, marshal, struct, sys, time, types
from ..compiler2 import consts
from cStringIO import StringIO


INDENT = '  '
@@ -46,32 +45,6 @@ def to_hexstr(bytes_value, level=0, wrap=False):
        return template % tuple(ord(char) for char in bytes_value)


def show_consts(consts, level=0):
    indent = INDENT * level
    i = 0
    for obj in consts:
        if isinstance(obj, types.CodeType):
            print(indent+"%s (code object)" % i)
            # RECURSIVE CALL.
            show_code(obj, level=level+1)
        else:
            print(indent+"%s %r" % (i, obj))
        i += 1


def show_bytecode(code, level=0):
    """Call dis.disassemble() to show bytecode."""
    indent = INDENT * level
    print(to_hexstr(code.co_code, level, wrap=True))
    print(indent+"disassembled:")
    buf = StringIO()
    sys.stdout = buf
    # NOTE: This format has addresses in it, disable for now
    dis.disassemble(code)
    sys.stdout = sys.__stdout__
    print(indent + buf.getvalue().replace("\n", "\n"+indent))


# TODO: Do this in a cleaner way.  Right now I'm avoiding modifying the
# consts module.
def build_flags_def(consts, co_flags_def):
@@ -97,35 +70,11 @@ def show_flags(value):
      return h


def show_code(code, level=0):
    """Print a code object, e.g. metadata, bytecode, and consts."""
    indent = INDENT * level

    for name in dir(code):
        if not name.startswith("co_"):
            continue
        if name in ("co_code", "co_consts"):
            continue
        value = getattr(code, name)
        if isinstance(value, str):
            value = repr(value)
        elif name == "co_flags":
            value = show_flags(value)
        elif name == "co_lnotab":
            value = "0x(%s)" % to_hexstr(value)
        print("%s%s%s" % (indent, (name+":").ljust(NAME_OFFSET), value))
    print("%sco_consts" % indent)
    show_consts(code.co_consts, level=level+1)
    print("%sco_code" % indent)
    show_bytecode(code, level=level+1)


def unpack_pyc(f):
    magic = f.read(4)
    unixtime = struct.unpack("I", f.read(4))[0]
    timestamp = time.asctime(time.localtime(unixtime))
    code = marshal.load(f)
    f.close()
    return magic, unixtime, timestamp, code


@@ -134,16 +83,136 @@ def unpack_pyc(f):
# objects.  Each code object contains constants, and a constant can be another
# code object.

# Enhancements:
# - Actually print the line of code!  That will be very helpful.
# - Print a histogram of byte codes.  Print toal number of bytecodes.
#   - Copy of the

def disassemble(co, indent, f):
  """Copied from dis module.

  It doesn't do the indent we want.
  """
  def ind(*args, **kwargs):
    print(indent, end='')
    print(*args, file=f, **kwargs)

  def out(*args, **kwargs):
    print(*args, file=f, **kwargs)

  code = co.co_code
  labels = dis.findlabels(code)
  linestarts = dict(dis.findlinestarts(co))
  n = len(code)
  i = 0
  extended_arg = 0
  free = None

  while i < n:
      c = code[i]
      op = ord(c)
      if i in linestarts:
          if i > 0:
              out()
          ind("%3d" % linestarts[i], end=' ')
      else:
          ind('   ', end=' ')

      out('   ', end=' ')
      if i in labels:  # Jump targets get a special symbol
        out('>>', end=' ')
      else:
        out('  ', end=' ')

      out(repr(i).rjust(4), end=' ')
      out(dis.opname[op].ljust(20), end=' ')
      i += 1
      if op >= dis.HAVE_ARGUMENT:
          oparg = ord(code[i]) + ord(code[i+1])*256 + extended_arg
          extended_arg = 0
          i += 2
          if op == dis.EXTENDED_ARG:
              extended_arg = oparg*65536L

          out(repr(oparg).rjust(5), end=' ')
          if op in dis.hasconst:
              out('(' + repr(co.co_consts[oparg]) + ')', end=' ')
          elif op in dis.hasname:
              out('(' + co.co_names[oparg] + ')', end=' ')
          elif op in dis.hasjrel:
              out('(to ' + repr(i + oparg) + ')', end=' ')
          elif op in dis.haslocal:
              out('(' + co.co_varnames[oparg] + ')', end=' ')
          elif op in dis.hascompare:
              out('(' + dis.cmp_op[oparg] + ')', end=' ')
          elif op in dis.hasfree:
              if free is None:
                  free = co.co_cellvars + co.co_freevars
              out('(' + free[oparg] + ')', end=' ')
      out()


class Visitor(object):

  def __init__(self, dis_bytecode=True):
    self.dis_bytecode = dis_bytecode  # Whether to show disassembly.

  def show_consts(self, consts, level=0):
    indent = INDENT * level
    i = 0
    for obj in consts:
      if isinstance(obj, types.CodeType):
        print(indent+"%s (code object)" % i)
        # RECURSIVE CALL.
        self.show_code(obj, level=level+1)
      else:
        print(indent+"%s %r" % (i, obj))
      i += 1

  def show_bytecode(self, code, level=0):
    """Call dis.disassemble() to show bytecode."""

    indent = INDENT * level
    print(to_hexstr(code.co_code, level, wrap=True))

    if self.dis_bytecode:
      print(indent + "disassembled:")
      disassemble(code, indent, sys.stdout)

def show_file(f):
  def show_code(self, code, level=0):
    """Print a code object, e.g. metadata, bytecode, and consts."""

    indent = INDENT * level

    for name in dir(code):
      if not name.startswith("co_"):
        continue
      if name in ("co_code", "co_consts"):
        continue
      value = getattr(code, name)
      if isinstance(value, str):
        value = repr(value)
      elif name == "co_flags":
        value = show_flags(value)
      elif name == "co_lnotab":
        value = "0x(%s)" % to_hexstr(value)
      print("%s%s%s" % (indent, (name+":").ljust(NAME_OFFSET), value))

    print("%sco_consts" % indent)
    self.show_consts(code.co_consts, level=level+1)

    print("%sco_code" % indent)
    self.show_bytecode(code, level=level+1)

  def Visit(self, f):
    """Write a readable listing of a .pyc file to stdout."""

    magic, unixtime, timestamp, code = unpack_pyc(f)

    magic = "0x(%s)" % to_hexstr(magic)

    print("  ## inspecting pyc file ##")
    print("magic number: %s" % magic)
    print("timestamp:    %s (%s)" % (unixtime, timestamp))
    print("code")
    show_code(code, level=1)
    self.show_code(code, level=1)
    print("  ## done inspecting pyc file ##")

opy/opy_main.py

@@ -265,7 +265,10 @@ def py2st(gr, raw_node):
  elif action == 'dis':
    pyc_path = argv[1]
    with open(pyc_path, 'rb') as f:
      inspect_pyc.show_file(f)
      # TODO: Make this a flag.
      #v = inspect_pyc.Visitor(dis_bytecode=False)
      v = inspect_pyc.Visitor()
      v.Visit(f)

  # NOTE: Unused
  elif action == 'old-compile':