#! /usr/bin/env python
"""A Python debugger."""
# (See pdb.doc for documentation.)
import string
import sys
import linecache
import cmd
import bdb
import repr
import os
import re
def find_function(funcname, filename):
cre = re.compile(r'def\s+%s\s*[(]' % funcname)
try:
fp = open(filename)
except IOError:
return None
# consumer of this info expects the first line to be 1
lineno = 1
answer = None
while 1:
line = fp.readline()
if line == '':
break
if cre.match(line):
answer = funcname, filename, lineno
break
lineno = lineno + 1
fp.close()
return answer
# Interaction prompt line will separate file and call info from code
# text using value of line_prefix string. A newline and arrow may
# be to your liking. You can set it once pdb is imported using the
# command "pdb.line_prefix = '\n% '".
# line_prefix = ': ' # Use this to get the old situation back
line_prefix = '\n-> ' # Probably a better default
class Pdb(bdb.Bdb, cmd.Cmd):
def __init__(self):
bdb.Bdb.__init__(self)
cmd.Cmd.__init__(self)
self.prompt = '(Pdb) '
self.aliases = {}
# Try to load readline if it exists
try:
import readline
except ImportError:
pass
# Read $HOME/.pdbrc and ./.pdbrc
self.rcLines = []
if os.environ.has_key('HOME'):
envHome = os.environ['HOME']
try:
rcFile = open (envHome + "/.pdbrc")
except IOError:
pass
else:
for line in rcFile.readlines():
self.rcLines.append (line)
rcFile.close()
try:
rcFile = open ("./.pdbrc")
except IOError:
pass
else:
for line in rcFile.readlines():
self.rcLines.append (line)
rcFile.close()
def reset(self):
bdb.Bdb.reset(self)
self.forget()
def forget(self):
self.lineno = None
self.stack = []
self.curindex = 0
self.curframe = None
def setup(self, f, t):
self.forget()
self.stack, self.curindex = self.get_stack(f, t)
self.curframe = self.stack[self.curindex][0]
self.execRcLines()
# Can be executed earlier than 'setup' if desired
def execRcLines(self):
if self.rcLines:
# Make local copy because of recursion
rcLines = self.rcLines
# executed only once
self.rcLines = []
for line in rcLines:
line = line[:-1]
if len (line) > 0 and line[0] != '#':
self.onecmd (line)
# Override Bdb methods (except user_call, for now)
def user_line(self, frame):
"""This function is called when we stop or break at this line."""
self.interaction(frame, None)
def user_return(self, frame, return_value):
"""This function is called when a return trap is set here."""
frame.f_locals['__return__'] = return_value
print '--Return--'
self.interaction(frame, None)
def user_exception(self, frame, (exc_type, exc_value, exc_traceback)):
"""This function is called if an exception occurs,
but only if we are to stop at or just below this level."""
frame.f_locals['__exception__'] = exc_type, exc_value
if type(exc_type) == type(''):
exc_type_name = exc_type
else: exc_type_name = exc_type.__name__
print exc_type_name + ':', repr.repr(exc_value)
self.interaction(frame, exc_traceback)
# General interaction function
def interaction(self, frame, traceback):
self.setup(frame, traceback)
self.print_stack_entry(self.stack[self.curindex])
self.cmdloop()
self.forget()
def default(self, line):
if line[:1] == '!': line = line[1:]
locals = self.curframe.f_locals
globals = self.curframe.f_globals
try:
code = compile(line + '\n', '<stdin>', 'single')
exec code in globals, locals
except:
t, v = sys.exc_info()[:2]
if type(t) == type(''):
exc_type_name = t
else: exc_type_name = t.__name__
print '***', exc_type_name + ':', v
def precmd(self, line):
"""Handle alias expansion and ';;' separator."""
if not line:
return line
args = string.split(line)
while self.aliases.has_key(args[0]):
line = self.aliases[args[0]]
ii = 1
for tmpArg in args[1:]:
line = string.replace(line, "%" + str(ii),
tmpArg)
ii = ii + 1
line = string.replace(line, "%*",
string.join(args[1:], ' '))
args = string.split(line)
# split into ';;' separated commands
# unless it's an alias command
if args[0] != 'alias':
marker = string.find(line, ';;')
if marker >= 0:
# queue up everything after marker
next = string.lstrip(line[marker+2:])
self.cmdqueue.append(next)
line = string.rstrip(line[:marker])
return line
# Command definitions, called by cmdloop()
# The argument is the remaining string on the command line
# Return true to exit from the command loop
do_h = cmd.Cmd.do_help
def do_EOF(self, arg):
return 0 # Don't die on EOF
def do_break(self, arg, temporary = 0):
# break [ ([filename:]lineno | function) [, "condition"] ]
if not arg:
if self.breaks: # There's at least one
print "Num Type Disp Enb Where"
for bp in bdb.Breakpoint.bpbynumber:
if bp:
bp.bpprint()
return
# parse arguments; comma has lowest precendence
# and cannot occur in filename
filename = None
lineno = None
cond = None
comma = string.find(arg, ',')
if comma > 0:
# parse stuff after comma: "condition"
cond = string.lstrip(arg[comma+1:])
arg = string.rstrip(arg[:comma])
# parse stuff before comma: [filename:]lineno | function
colon = string.rfind(arg, ':')
if colon >= 0:
filename = string.rstrip(arg[:colon])
f = self.lookupmodule(filename)
if not f:
print '*** ', `filename`,
print 'not found from sys.path'
return
else:
filename = f
arg = string.lstrip(arg[colon+1:])
try:
lineno = int(arg)
except ValueError, msg:
print '*** Bad lineno:', arg
return
else:
# no colon; can be lineno or function
try:
lineno = int(arg)
except ValueError:
try:
func = eval(arg,
self.curframe.f_globals,
self.curframe.f_locals)
except:
func = arg
try:
if hasattr(func, 'im_func'):
func = func.im_func
code = func.func_code
lineno = code.co_firstlineno
filename = code.co_filename
except:
# last thing to try
(ok, filename, ln) = self.lineinfo(arg)
if not ok:
print '*** The specified object',
print `arg`,
print 'is not a function'
print ('or was not found '
'along sys.path.')
return
lineno = int(ln)
if not filename:
filename = self.defaultFile()
# Check for reasonable breakpoint
line = self.checkline(filename, lineno)
if line:
# now set the break point
err = self.set_break(filename, line, temporary, cond)
if err: print '***', err
else:
bp = self.get_breaks(filename, line)[-1]
print "Breakpoint %d at %s:%d" % (bp.number,
bp.file,
bp.line)
# To be overridden in derived debuggers
def defaultFile(self):
"""Produce a reasonable default."""
filename = self.curframe.f_code.co_filename
if filename == '<string>' and mainpyfile:
filename = mainpyfile
return filename
do_b = do_break
def do_tbreak(self, arg):
self.do_break(arg, 1)
def lineinfo(self, identifier):
failed = (None, None, None)
# Input is identifier, may be in single quotes
idstring = string.split(identifier, "'")
if len(idstring) == 1:
# not in single quotes
id = string.strip(idstring[0])
elif len(idstring) == 3:
# quoted
id = string.strip(idstring[1])
else:
return failed
if id == '': return failed
parts = string.split(id, '.')
# Protection for derived debuggers
if parts[0] == 'self':
del parts[0]
if len(parts) == 0:
return failed
# Best first guess at file to look at
fname = self.defaultFile()
if len(parts) == 1:
item = parts[0]
else:
# More than one part.
# First is module, second is method/class
f = self.lookupmodule(parts[0])
if f:
fname = f
item = parts[1]
answer = find_function(item, fname)
return answer or failed
def checkline(self, filename, lineno):
"""Return line number of first line at or after input
argument such that if the input points to a 'def', the
returned line number is the first
non-blank/non-comment line to follow. If the input
points to a blank or comment line, return 0. At end
of file, also return 0."""
line = linecache.getline(filename, lineno)
if not line:
print 'End of file'
return 0
line = string.strip(line)
# Don't allow setting breakpoint at a blank line
if ( not line or (line[0] == '#') or
(line[:3] == '"""') or line[:3] == "'''" ):
print '*** Blank or comment'
return 0
# When a file is read in and a breakpoint is at
# the 'def' statement, the system stops there at
# code parse time. We don't want that, so all breakpoints
# set at 'def' statements are moved one line onward
if line[:3] == 'def':
instr = ''
brackets = 0
while 1:
skipone = 0
for c in line:
if instr:
if skipone:
skipone = 0
elif c == '\\':
skipone = 1
elif c == instr:
instr = ''
elif c == '#':
break
elif c in ('"',"'"):
instr = c
elif c in ('(','{','['):
brackets = brackets + 1
elif c in (')','}',']'):
brackets = brackets - 1
lineno = lineno+1
line = linecache.getline(filename, lineno)
if not line:
print 'end of file'
return 0
line = string.strip(line)
if not line: continue # Blank line
if brackets <= 0 and line[0] not in ('#','"',"'"):
break
return lineno
def do_enable(self, arg):
args = string.split(arg)
for i in args:
bp = bdb.Breakpoint.bpbynumber[int(i)]
if bp:
bp.enable()
def do_disable(self, arg):
args = string.split(arg)
for i in args:
bp = bdb.Breakpoint.bpbynumber[int(i)]
if bp:
bp.disable()
def do_condition(self, arg):
# arg is breakpoint number and condition
args = string.split(arg, ' ', 1)
bpnum = int(string.strip(args[0]))
try:
cond = args[1]
except:
cond = None
bp = bdb.Breakpoint.bpbynumber[bpnum]
if bp:
bp.cond = cond
if not cond:
print 'Breakpoint', bpnum,
print 'is now unconditional.'
def do_ignore(self,arg):
"""arg is bp number followed by ignore count."""
args = string.split(arg)
bpnum = int(string.strip(args[0]))
try:
count = int(string.strip(args[1]))
except:
count = 0
bp = bdb.Breakpoint.bpbynumber[bpnum]
if bp:
bp.ignore = count
if (count > 0):
reply = 'Will ignore next '
if (count > 1):
reply = reply + '%d crossings' % count
else:
reply = reply + '1 crossing'
print reply + ' of breakpoint %d.' % bpnum
else:
print 'Will stop next time breakpoint',
print bpnum, 'is reached.'
def do_clear(self, arg):
"""Three possibilities, tried in this order:
clear -> clear all breaks, ask for confirmation
clear file:lineno -> clear all breaks at file:lineno
clear bpno bpno ... -> clear breakpoints by number"""
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.clear_all_breaks()
return
if ':' in arg:
# Make sure it works for "clear C:\foo\bar.py:12"
i = string.rfind(arg, ':')
filename = arg[:i]
arg = arg[i+1:]
try:
lineno = int(arg)
except:
err = "Invalid line number (%s)" % arg
else:
err = self.clear_break(filename, lineno)
if err: print '***', err
return
numberlist = string.split(arg)
for i in numberlist:
err = self.clear_bpbynumber(i)
if err:
print '***', err
else:
print 'Deleted breakpoint %s ' % (i,)
do_cl = do_clear # 'c' is already an abbreviation for 'continue'
def do_where(self, arg):
self.print_stack_trace()
do_w = do_where
def do_up(self, arg):
if self.curindex == 0:
print '*** Oldest frame'
else:
self.curindex = self.curindex - 1
self.curframe = self.stack[self.curindex][0]
self.print_stack_entry(self.stack[self.curindex])
self.lineno = None
do_u = do_up
def do_down(self, arg):
if self.curindex + 1 == len(self.stack):
print '*** Newest frame'
else:
self.curindex = self.curindex + 1
self.curframe = self.stack[self.curindex][0]
self.print_stack_entry(self.stack[self.curindex])
self.lineno = None
do_d = do_down
def do_step(self, arg):
self.set_step()
return 1
do_s = do_step
def do_next(self, arg):
self.set_next(self.curframe)
return 1
do_n = do_next
def do_return(self, arg):
self.set_return(self.curframe)
return 1
do_r = do_return
def do_continue(self, arg):
self.set_continue()
return 1
do_c = do_cont = do_continue
def do_quit(self, arg):
self.set_quit()
return 1
do_q = do_quit
def do_args(self, arg):
f = self.curframe
co = f.f_code
dict = f.f_locals
n = co.co_argcount
if co.co_flags & 4: n = n+1
if co.co_flags & 8: n = n+1
for i in range(n):
name = co.co_varnames[i]
print name, '=',
if dict.has_key(name): print dict[name]
else: print "*** undefined ***"
do_a = do_args
def do_retval(self, arg):
if self.curframe.f_locals.has_key('__return__'):
print self.curframe.f_locals['__return__']
else:
print '*** Not yet returned!'
do_rv = do_retval
def do_p(self, arg):
try:
value = eval(arg, self.curframe.f_globals,
self.curframe.f_locals)
except:
t, v = sys.exc_info()[:2]
if type(t) == type(''):
exc_type_name = t
else: exc_type_name = t.__name__
print '***', exc_type_name + ':', `v`
return
print `value`
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 = max(1, int(x) - 5)
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 == None:
last = first + 10
filename = self.curframe.f_code.co_filename
breaklist = self.get_file_breaks(filename)
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_whatis(self, arg):
try:
value = eval(arg, self.curframe.f_globals,
self.curframe.f_locals)
except:
t, v = sys.exc_info()[:2]
if type(t) == type(''):
exc_type_name = t
else: exc_type_name = t.__name__
print '***', exc_type_name + ':', `v`
return
code = None
# Is it a function?
try: code = value.func_code
except: pass
if code:
print 'Function', code.co_name
return
# Is it an instance method?
try: code = value.im_func.func_code
except: pass
if code:
print 'Method', code.co_name
return
# None of the above...
print type(value)
def do_alias(self, arg):
args = string.split (arg)
if len(args) == 0:
keys = self.aliases.keys()
keys.sort()
for alias in keys:
print "%s = %s" % (alias, self.aliases[alias])
return
if self.aliases.has_key(args[0]) and len (args) == 1:
print "%s = %s" % (args[0], self.aliases[args[0]])
else:
self.aliases[args[0]] = string.join(args[1:], ' ')
def do_unalias(self, arg):
args = string.split (arg)
if len(args) == 0: return
if self.aliases.has_key(args[0]):
del self.aliases[args[0]]
# Print a traceback starting at the top stack frame.
# The most recently entered frame is printed last;
# this is different from dbx and gdb, but consistent with
# the Python interpreter's stack trace.
# It is also consistent with the up/down commands (which are
# compatible with dbx and gdb: up moves towards 'main()'
# and down moves towards the most recent stack frame).
def print_stack_trace(self):
try:
for frame_lineno in self.stack:
self.print_stack_entry(frame_lineno)
except KeyboardInterrupt:
pass
def print_stack_entry(self, frame_lineno, prompt_prefix=line_prefix):
frame, lineno = frame_lineno
if frame is self.curframe:
print '>',
else:
print ' ',
print self.format_stack_entry(frame_lineno, prompt_prefix)
# Help methods (derived from pdb.doc)
def help_help(self):
self.help_h()
def help_h(self):
print """h(elp)
Without argument, print the list of available commands.
With a command name as argument, print help about that command
"help pdb" pipes the full documentation file to the $PAGER
"help exec" gives help on the ! command"""
def help_where(self):
self.help_w()
def help_w(self):
print """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."""
def help_down(self):
self.help_d()
def help_d(self):
print """d(own)
Move the current frame one level down in the stack trace
(to an older frame)."""
def help_up(self):
self.help_u()
def help_u(self):
print """u(p)
Move the current frame one level up in the stack trace
(to a newer frame)."""
def help_break(self):
self.help_b()
def help_b(self):
print """b(reak) ([file:]lineno | function) [, condition]
With a line number argument, set a break there in the current
file. With a function name, set a break at first executable line
of that function. Without argument, list all breaks. If a second
argument is present, it is a string specifying an expression
which must evaluate to true before the breakpoint is honored.
The line number may be prefixed with a filename and a colon,
to specify a breakpoint in another file (probably one that
hasn't been loaded yet). The file is searched for on sys.path;
the .py suffix may be omitted."""
def help_clear(self):
self.help_cl()
def help_cl(self):
print "cl(ear) filename:lineno"
print """cl(ear) [bpnumber [bpnumber...]]
With a space separated list of breakpoint numbers, clear
those breakpoints. Without argument, clear all breaks (but
first ask confirmation). With a filename:lineno argument,
clear all breaks at that line in that file.
Note that the argument is different from previous versions of
the debugger (in python distributions 1.5.1 and before) where
a linenumber was used instead of either filename:lineno or
breakpoint numbers."""
def help_tbreak(self):
print """tbreak same arguments as break, but breakpoint is
removed when first hit."""
def help_enable(self):
print """enable bpnumber [bpnumber ...]
Enables the breakpoints given as a space separated list of
bp numbers."""
def help_disable(self):
print """disable bpnumber [bpnumber ...]
Disables the breakpoints given as a space separated list of
bp numbers."""
def help_ignore(self):
print """ignore bpnumber count
Sets the ignore count for the given breakpoint number. A breakpoint
becomes active when the ignore count is zero. When non-zero, the
count is decremented each time the breakpoint is reached and the
breakpoint is not disabled and any associated condition evaluates
to true."""
def help_condition(self):
print """condition bpnumber str_condition
str_condition is a string specifying an expression which
must evaluate to true before the breakpoint is honored.
If str_condition is absent, any existing condition is removed;
i.e., the breakpoint is made unconditional."""
def help_step(self):
self.help_s()
def help_s(self):
print """s(tep)
Execute the current line, stop at the first possible occasion
(either in a function that is called or in the current function)."""
def help_next(self):
self.help_n()
def help_n(self):
print """n(ext)
Continue execution until the next line in the current function
is reached or it returns."""
def help_return(self):
self.help_r()
def help_r(self):
print """r(eturn)
Continue execution until the current function returns."""
def help_continue(self):
self.help_c()
def help_cont(self):
self.help_c()
def help_c(self):
print """c(ont(inue))
Continue execution, only stop when a breakpoint is encountered."""
def help_list(self):
self.help_l()
def help_l(self):
print """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."""
def help_args(self):
self.help_a()
def help_a(self):
print """a(rgs)
Print the arguments of the current function."""
def help_p(self):
print """p expression
Print the value of the expression."""
def help_exec(self):
print """(!) 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)"""
def help_quit(self):
self.help_q()
def help_q(self):
print """q(uit) Quit from the debugger.
The program being executed is aborted."""
def help_whatis(self):
print """whatis arg
Prints the type of the argument."""
def help_EOF(self):
print """EOF
Handles the receipt of EOF as a command."""
def help_alias(self):
print """alias [name [command [parameter parameter ...] ]]
Creates an alias called 'name' the executes 'command'. The command
must *not* be enclosed in quotes. Replaceable parameters are
indicated by %1, %2, and so on, while %* is replaced by all the
parameters. If no command is given, the current alias for name
is shown. If no name is given, all aliases are listed.
Aliases may be nested and can contain anything that can be
legally typed at the pdb prompt. Note! You *can* override
internal pdb commands with aliases! Those internal commands
are then hidden until the alias is removed. Aliasing is recursively
applied to the first word of the command line; all other words
in the line are left alone.
Some useful aliases (especially when placed in the .pdbrc file) are:
#Print instance variables (usage "pi classInst")
alias pi for k in %1.__dict__.keys(): print "%1.",k,"=",%1.__dict__[k]
#Print instance variables in self
alias ps pi self
"""
def help_unalias(self):
print """unalias name
Deletes the specified alias."""
def help_pdb(self):
help()
def lookupmodule(self, filename):
"""Helper function for break/clear parsing -- may be overridden."""
root, ext = os.path.splitext(filename)
if ext == '':
filename = filename + '.py'
if os.path.isabs(filename):
return filename
for dirname in sys.path:
while os.path.islink(dirname):
dirname = os.readlink(dirname)
fullname = os.path.join(dirname, filename)
if os.path.exists(fullname):
return fullname
return None
# Simplified interface
def run(statement, globals=None, locals=None):
Pdb().run(statement, globals, locals)
def runeval(expression, globals=None, locals=None):
return Pdb().runeval(expression, globals, locals)
def runctx(statement, globals, locals):
# B/W compatibility
run(statement, globals, locals)
def runcall(*args):
return apply(Pdb().runcall, args)
def set_trace():
Pdb().set_trace()
# Post-Mortem interface
def post_mortem(t):
p = Pdb()
p.reset()
while t.tb_next <> None: t = t.tb_next
p.interaction(t.tb_frame, t)
def pm():
post_mortem(sys.last_traceback)
# Main program for testing
TESTCMD = 'import x; x.main()'
def test():
run(TESTCMD)
# print help
def help():
for dirname in sys.path:
fullname = os.path.join(dirname, 'pdb.doc')
if os.path.exists(fullname):
sts = os.system('${PAGER-more} '+fullname)
if sts: print '*** Pager exit status:', sts
break
else:
print 'Sorry, can\'t find the help file "pdb.doc"',
print 'along the Python search path'
mainmodule = ''
mainpyfile = ''
# When invoked as main program, invoke the debugger on a script
if __name__=='__main__':
if not sys.argv[1:]:
print "usage: pdb.py scriptfile [arg] ..."
sys.exit(2)
mainpyfile = filename = sys.argv[1] # Get script filename
if not os.path.exists(filename):
print 'Error:', `filename`, 'does not exist'
sys.exit(1)
mainmodule = os.path.basename(filename)
del sys.argv[0] # Hide "pdb.py" from argument list
# Insert script directory in front of module search path
sys.path.insert(0, os.path.dirname(filename))
run('execfile(' + `filename` + ')')
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