607 lines
16 KiB
Python
Executable File
607 lines
16 KiB
Python
Executable File
# pdb.py -- finally, a Python debugger! See below for instructions.
|
|
|
|
|
|
# To do:
|
|
# - Keep a list of exceptions trapped (default only KeyboardInterrupt?)
|
|
# - It should be possible to intercept KeyboardInterrupt completely
|
|
# - Handle return events differently (how?)
|
|
# - When stopping on an exception, show traceback stack
|
|
# - Merge with tb (for post-mortem usage)
|
|
# - Show stack traces upside-down (like dbx/gdb) ???
|
|
# (actually, the current way is more natural given the directions
|
|
# taken by the up/down commands)
|
|
|
|
|
|
# To use the debugger in its simplest form:
|
|
# >>> import pdb
|
|
# >>> pdb.run('<a statement>')
|
|
# The debugger's prompt is '(Pdb) '.
|
|
# This will stop in the first function call in <a statement>.
|
|
|
|
# The commands recognized by the debugger are listed below.
|
|
# Most can be abbreviated as indicated; e.g., h(elp) means that
|
|
# 'help' can be typed as 'h' or 'help'
|
|
# (but not as 'he' or 'hel', nor as 'H' or 'Help' or 'HELP').
|
|
# Optional arguments are enclosed in square brackets.
|
|
|
|
# A blank line repeats the previous command literally.
|
|
# (Except for 'list', where it lists the next 11 lines.)
|
|
|
|
# Commands that the debugger does not recognized are assumed to
|
|
# be Python statements and are executed in the context of the
|
|
# program being debugged.
|
|
# Python statements can also be prefixed with an exclamation point ('!').
|
|
# This is a powerful way to inspect the program being debugged;
|
|
# it is even possible to change variables.
|
|
# When an exception occurs in such a statement, the exception name
|
|
# is printed but the debugger's state is not changed.
|
|
|
|
# The debugger is not directly programmable; but it is implemented
|
|
# as a class from which you can derive your own debugger class,
|
|
# so you can make as fancy as you like.
|
|
|
|
# The debugger's commands are:
|
|
|
|
# h(elp)
|
|
# Without argument, print the list of available commands.
|
|
# With a command name as argument, print help about that command
|
|
# (this is currently not implemented).
|
|
|
|
# w(here)
|
|
# Print a stack trace, with the most recent frame at the bottom.
|
|
# An arrow indicates the "current frame", which determines the
|
|
# context of most commands.
|
|
|
|
# d(own)
|
|
# Move the current frame one level down in the stack trace
|
|
# (to an older frame).
|
|
|
|
# u(p)
|
|
# Move the current frame one level up in the stack trace
|
|
# (to a newer frame).
|
|
|
|
# b(reak) [lineno]
|
|
# With a line number argument, set a break there in the current file.
|
|
# Without argument, list all breaks.
|
|
|
|
# cl(ear) [lineno]
|
|
# With a line number argument, clear that break in the current file.
|
|
# Without argument, clear all breaks (but first ask confirmation).
|
|
|
|
# s(tep)
|
|
# Execute the current line, stop at the first possible occasion
|
|
# (either in a function that is called or in the current function).
|
|
|
|
# n(ext)
|
|
# Continue execution until the next line in the current function
|
|
# is reached or it returns.
|
|
|
|
# r(eturn)
|
|
# Continue execution until the current function returns.
|
|
|
|
# c(ont(inue))
|
|
# Continue execution, only stop when a breakpoint is encountered.
|
|
|
|
# l(ist) [first [,last]]
|
|
# List source code for the current file.
|
|
# Without arguments, list 11 lines around the current line
|
|
# or continue the previous listing.
|
|
# With one argument, list 11 lines starting at that line.
|
|
# With two arguments, list the given range;
|
|
# if the second argument is less than the first, it is a count.
|
|
|
|
# a(rgs)
|
|
# Print the argument list of the current function.
|
|
|
|
# p expression
|
|
# Print the value of the expression.
|
|
|
|
# (!) statement
|
|
# Execute the (one-line) statement in the context of
|
|
# the current stack frame.
|
|
# The exclamation point can be omitted unless the first word
|
|
# of the statement resembles a debugger command.
|
|
# To assign to a global variable you must always prefix the
|
|
# command with a 'global' command, e.g.:
|
|
# (Pdb) global list_options; list_options = ['-l']
|
|
# (Pdb)
|
|
|
|
# q(uit)
|
|
# Quit from the debugger.
|
|
# The program being executed is aborted.
|
|
|
|
|
|
# Here's how it works.
|
|
|
|
# Some changes were made to the interpreter:
|
|
# - if sys.trace is defined (by the user), it should be a function
|
|
# - sys.trace is called the global trace function
|
|
# - there can also a local trace function (see later)
|
|
|
|
# Trace functions have three arguments: (frame, event, arg)
|
|
# - frame is the current stack frame
|
|
# - event is a string: 'call', 'line', 'return' or 'exception'
|
|
# - arg is dependent on the event type
|
|
# A trace function should return a new trace function or None.
|
|
# Class methods are accepted (and most useful!) as trace methods.
|
|
|
|
# The events have the following meaning:
|
|
#
|
|
# 'call': A function is called (or some other code block entered).
|
|
# The global trace function is called;
|
|
# arg is the argument list to the function;
|
|
# the return value specifies the local trace function.
|
|
#
|
|
# 'line': The interpreter is about to execute a new line of code
|
|
# (sometimes multiple line events on one line exist).
|
|
# The local trace function is called; arg in None;
|
|
# the return value specifies the new local trace function.
|
|
#
|
|
# 'return': A function (or other code block) is about to return.
|
|
# The local trace function is called;
|
|
# arg is the value that will be returned.
|
|
# The trace function's return value is ignored.
|
|
#
|
|
# 'exception': An exception has occurred.
|
|
# The local trace function is called if there is one,
|
|
# else the global trace function is called;
|
|
# arg is a triple (exception, value, traceback);
|
|
# the return value specifies the new local trace function
|
|
#
|
|
# Note that as an exception is propagated down the chain of callers,
|
|
# an 'exception' event is generated at each level.
|
|
|
|
# A stack frame object has the following read-only attributes:
|
|
# f_code: the code object being executed
|
|
# f_lineno: the current line number (-1 for 'call' events)
|
|
# f_back: the stack frame of the caller, or None
|
|
# f_locals: dictionary containing local name bindings
|
|
# f_globals: dictionary containing global name bindings
|
|
|
|
# A code object has the following read-only attributes:
|
|
# co_code: the code string
|
|
# co_names: the list of names used by the code
|
|
# co_consts: the list of (literal) constants used by the code
|
|
# co_filename: the filename from which the code was compiled
|
|
|
|
|
|
import string
|
|
import sys
|
|
import linecache
|
|
|
|
|
|
# A generic class to build command interpreters
|
|
|
|
PROMPT = '(Cmd) '
|
|
IDENTCHARS = string.letters + string.digits + '_'
|
|
|
|
class Cmd:
|
|
def init(self):
|
|
self.prompt = PROMPT
|
|
self.identchars = IDENTCHARS
|
|
self.lastcmd = ''
|
|
return self
|
|
def cmdloop(self):
|
|
stop = None
|
|
while not stop:
|
|
try:
|
|
line = raw_input(self.prompt)
|
|
except EOFError:
|
|
line = 'EOF'
|
|
stop = self.onecmd(line)
|
|
return stop
|
|
def onecmd(self, line):
|
|
line = string.strip(line)
|
|
if not line:
|
|
line = self.lastcmd
|
|
print line
|
|
else:
|
|
self.lastcmd = line
|
|
i, n = 0, len(line)
|
|
while i < n and line[i] in self.identchars: i = i+1
|
|
cmd, arg = line[:i], string.strip(line[i:])
|
|
if cmd == '':
|
|
return self.default(line)
|
|
else:
|
|
try:
|
|
func = eval('self.do_' + cmd)
|
|
except AttributeError:
|
|
return self.default(line)
|
|
return func(arg)
|
|
def default(self, line):
|
|
print '*** Unknown syntax:', line
|
|
def do_help(self, arg):
|
|
if arg:
|
|
# XXX check arg syntax
|
|
try:
|
|
func = eval('self.help_' + arg)
|
|
except:
|
|
print '*** No help on', `arg`
|
|
return
|
|
func()
|
|
else:
|
|
import getattr
|
|
names = getattr.dir(self)
|
|
cmds = []
|
|
for name in names:
|
|
if name[:3] == 'do_':
|
|
cmds.append(name[3:])
|
|
print cmds
|
|
|
|
|
|
# A specialization of Cmd for use by the debugger
|
|
|
|
PdbQuit = 'pdb.PdbQuit' # Exception to give up
|
|
|
|
class Pdb(Cmd):
|
|
|
|
def init(self):
|
|
self = Cmd.init(self)
|
|
self.prompt = '(Pdb) '
|
|
self.reset()
|
|
return self
|
|
|
|
def reset(self):
|
|
self.breaks = {}
|
|
self.botframe = None
|
|
self.stopframe = None
|
|
self.forget()
|
|
|
|
def forget(self):
|
|
self.setup(None)
|
|
|
|
def setup(self, frame):
|
|
self.curframe = self.topframe = frame
|
|
self.stack = []
|
|
self.lineno = None
|
|
|
|
def run(self, cmd):
|
|
import __main__
|
|
dict = __main__.__dict__
|
|
self.runctx(cmd, dict, dict)
|
|
|
|
def runctx(self, cmd, globals, locals):
|
|
self.reset()
|
|
sys.trace = self.dispatch
|
|
try:
|
|
exec(cmd + '\n', globals, locals)
|
|
except PdbQuit:
|
|
pass
|
|
finally:
|
|
sys.trace = None
|
|
del sys.trace
|
|
self.reset()
|
|
|
|
def dispatch(self, frame, event, arg):
|
|
if event == 'line':
|
|
return self.dispatch_line(frame)
|
|
if event == 'call':
|
|
return self.dispatch_call(frame, arg)
|
|
if event == 'return':
|
|
return self.dispatch_return(frame, arg)
|
|
if event == 'exception':
|
|
return self.dispatch_exception(frame, arg)
|
|
print '*** dispatch: unknown event type', `event`
|
|
return self.dispatch
|
|
|
|
def dispatch_line(self, frame):
|
|
if self.stop_here(frame) or self.break_here(frame):
|
|
self.ask_user(frame)
|
|
return self.dispatch
|
|
|
|
def dispatch_call(self, frame, arg):
|
|
if self.botframe is None:
|
|
self.botframe = frame
|
|
return
|
|
if not (self.stop_here(frame) or self.break_anywhere(frame)):
|
|
return
|
|
frame.f_locals['__args__'] = arg
|
|
return self.dispatch
|
|
|
|
def dispatch_return(self, frame, arg):
|
|
if self.stop_here(frame):
|
|
print '!!! return', `arg`
|
|
return
|
|
|
|
def dispatch_exception(self, frame, arg):
|
|
if arg[0] is PdbQuit: return None
|
|
if self.stop_here(frame):
|
|
print '!!! exception', arg[0] + ':', `arg[1]`
|
|
self.ask_user(frame)
|
|
return self.dispatch
|
|
|
|
def stop_here(self, frame):
|
|
if self.stopframe is None:
|
|
return 1
|
|
if frame is self.stopframe:
|
|
return 1
|
|
while frame is not self.stopframe:
|
|
if frame is None:
|
|
return 1
|
|
frame = frame.f_back
|
|
return 0
|
|
|
|
def break_here(self, frame):
|
|
if not self.breaks.has_key(frame.f_code.co_filename):
|
|
return 0
|
|
if not frame.f_lineno in \
|
|
self.breaks[frame.f_code.co_filename]:
|
|
return 0
|
|
return 1
|
|
|
|
def break_anywhere(self, frame):
|
|
return self.breaks.has_key(frame.f_code.co_filename)
|
|
|
|
def ask_user(self, frame):
|
|
self.setup(frame)
|
|
self.printwhere(self.curframe)
|
|
dummy = self.cmdloop()
|
|
self.forget()
|
|
|
|
def default(self, line):
|
|
if not line:
|
|
return self.do_next('')
|
|
else:
|
|
if line[0] == '!': line = line[1:]
|
|
try:
|
|
exec(line + '\n', \
|
|
self.curframe.f_globals, \
|
|
self.curframe.f_locals)
|
|
except:
|
|
print '***', sys.exc_type + ':',
|
|
print `sys.exc_value`
|
|
|
|
do_h = Cmd.do_help
|
|
|
|
def do_break(self, arg):
|
|
if not arg:
|
|
print self.breaks # XXX
|
|
return
|
|
try:
|
|
lineno = int(eval(arg))
|
|
except:
|
|
print '*** Error in argument:', `arg`
|
|
return
|
|
filename = self.curframe.f_code.co_filename
|
|
line = linecache.getline(filename, lineno)
|
|
if not line:
|
|
print '*** That line does not exist!'
|
|
return
|
|
if not self.breaks.has_key(filename):
|
|
self.breaks[filename] = []
|
|
list = self.breaks[filename]
|
|
if lineno in list:
|
|
print '*** There is already a break there!'
|
|
return
|
|
list.append(lineno)
|
|
do_b = do_break
|
|
|
|
def do_clear(self, arg):
|
|
if not arg:
|
|
try:
|
|
reply = raw_input('Clear all breaks? ')
|
|
except EOFError:
|
|
reply = 'no'
|
|
reply = string.lower(string.strip(reply))
|
|
if reply in ('y', 'yes'):
|
|
self.breaks = {}
|
|
return
|
|
try:
|
|
lineno = int(eval(arg))
|
|
except:
|
|
print '*** Error in argument:', `arg`
|
|
return
|
|
filename = self.curframe.f_code.co_filename
|
|
try:
|
|
self.breaks[filename].remove(lineno)
|
|
except (ValueError, KeyError):
|
|
print '*** There is no break there!'
|
|
return
|
|
if not self.breaks[filename]:
|
|
del self.breaks[filename]
|
|
do_cl = do_clear # 'c' is already an abbreviation for 'continue'
|
|
|
|
def do_where(self, arg):
|
|
self.printtb()
|
|
do_w = do_where
|
|
|
|
def do_up(self, arg):
|
|
if self.curframe == self.botframe or \
|
|
not self.curframe.f_back: print '*** Top'
|
|
else:
|
|
self.stack.append(self.curframe)
|
|
self.curframe = self.curframe.f_back
|
|
self.lineno = None
|
|
self.printwhere(self.curframe)
|
|
do_u = do_up
|
|
|
|
def do_down(self, arg):
|
|
if not self.stack: print '*** Bottom'
|
|
else:
|
|
self.curframe = self.stack[-1]
|
|
self.lineno = None
|
|
del self.stack[-1]
|
|
self.printwhere(self.curframe)
|
|
do_d = do_down
|
|
|
|
def do_step(self, arg):
|
|
self.stopframe = None
|
|
return 1
|
|
do_s = do_step
|
|
|
|
def do_next(self, arg):
|
|
self.stopframe = self.curframe
|
|
return 1
|
|
do_n = do_next
|
|
|
|
def do_return(self, arg):
|
|
self.stopframe = self.curframe.f_back
|
|
return 1
|
|
do_r = do_return
|
|
|
|
def do_continue(self, arg):
|
|
self.stopframe = self.botframe
|
|
return 1
|
|
do_c = do_cont = do_continue
|
|
|
|
def do_quit(self, arg):
|
|
self.stopframe = self.botframe
|
|
raise PdbQuit
|
|
do_q = do_quit
|
|
|
|
def do_list(self, arg):
|
|
self.lastcmd = 'list'
|
|
last = None
|
|
if arg:
|
|
try:
|
|
x = eval(arg, {}, {})
|
|
if type(x) == type(()):
|
|
first, last = x
|
|
first = int(first)
|
|
last = int(last)
|
|
if last < first:
|
|
# Assume it's a count
|
|
last = first + last
|
|
else:
|
|
first = int(x)
|
|
except:
|
|
print '*** Error in argument:', `arg`
|
|
return
|
|
elif self.lineno is None:
|
|
first = max(1, self.curframe.f_lineno - 5)
|
|
else:
|
|
first = self.lineno + 1
|
|
if last is None:
|
|
last = first + 10
|
|
filename = self.curframe.f_code.co_filename
|
|
if self.breaks.has_key(filename):
|
|
breaklist = self.breaks[filename]
|
|
else:
|
|
breaklist = []
|
|
try:
|
|
for lineno in range(first, last+1):
|
|
line = linecache.getline(filename, lineno)
|
|
if not line:
|
|
print '[EOF]'
|
|
break
|
|
else:
|
|
s = string.rjust(`lineno`, 3)
|
|
if len(s) < 4: s = s + ' '
|
|
if lineno in breaklist: s = s + 'B'
|
|
else: s = s + ' '
|
|
if lineno == self.curframe.f_lineno:
|
|
s = s + '->'
|
|
print s + '\t' + line,
|
|
self.lineno = lineno
|
|
except KeyboardInterrupt:
|
|
pass
|
|
do_l = do_list
|
|
|
|
def do_args(self, arg):
|
|
try:
|
|
value = eval('__args__', self.curframe.f_globals, \
|
|
self.curframe.f_locals)
|
|
except:
|
|
print '***', sys.exc_type + ':', `sys.exc_value`
|
|
return
|
|
print `value`
|
|
do_a = do_args
|
|
|
|
def do_p(self, arg):
|
|
try:
|
|
value = eval(arg, self.curframe.f_globals, \
|
|
self.curframe.f_locals)
|
|
except:
|
|
print '***', sys.exc_type + ':', `sys.exc_value`
|
|
return
|
|
print `value`
|
|
|
|
# Print a traceback starting at a given stack frame
|
|
# Note that it is printed upside-down with respect
|
|
# to the orientation suggested by the up/down commands.
|
|
# This is consistent with gdb.
|
|
def printtb(self):
|
|
list = []
|
|
frame = self.topframe
|
|
while frame:
|
|
list.append(frame)
|
|
if frame is self.botframe: break
|
|
frame = frame.f_back
|
|
list.reverse()
|
|
for frame in list:
|
|
self.printwhere(frame)
|
|
|
|
def printwhere(self, frame):
|
|
if frame is self.curframe: print '->',
|
|
code = frame.f_code
|
|
filename = code.co_filename
|
|
lineno = frame.f_lineno
|
|
print filename + '(' + `lineno` + ')',
|
|
line = linecache.getline(filename, lineno)
|
|
if line: print string.strip(line),
|
|
print
|
|
|
|
|
|
# --------------------- testing ---------------------
|
|
|
|
# The Ackermann function -- a highly recursive beast
|
|
cheat = 0
|
|
cache = {}
|
|
def ack(x, y):
|
|
key = `(long(x), long(y))`
|
|
if cache.has_key(key):
|
|
res = cache[key]
|
|
else:
|
|
if x == 0:
|
|
res = 1L
|
|
elif y == 0:
|
|
if x == 1:
|
|
res = 2L
|
|
else:
|
|
res = 2L + x
|
|
elif y == 1 and cheat >= 1:
|
|
res = 2L * x
|
|
elif y == 2 and cheat >= 2:
|
|
res = pow(2L, x)
|
|
else:
|
|
res = ack(ack(x-1, y), y-1)
|
|
cache[key] = res
|
|
return res
|
|
|
|
def foo(n):
|
|
print 'foo', n
|
|
x = bar(n*2)
|
|
print 'bar returned', x
|
|
return
|
|
|
|
def bar(a):
|
|
print 'bar', a
|
|
return a*10
|
|
|
|
def test():
|
|
linecache.checkcache()
|
|
Pdb().init().run('foo(12)\n')
|
|
|
|
|
|
# --------------------- main ---------------------
|
|
|
|
import os
|
|
|
|
def main():
|
|
if sys.argv[1:]:
|
|
file = sys.argv[1]
|
|
head, tail = os.path.split(file)
|
|
if tail[-3:] != '.py':
|
|
print 'Sorry, file arg must be a python module'
|
|
print '(i.e., must end in \'.py\')'
|
|
# XXX Or we could copy it to a temp file
|
|
sys.exit(2)
|
|
del sys.argv[0]
|
|
sys.path.insert(0, head)
|
|
run('import ' + tail[:-3])
|
|
else:
|
|
run('')
|
|
|
|
def run(statement):
|
|
Pdb().init().run(statement)
|