#! /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 __all__ = ["run", "pm", "Pdb", "runeval", "runctx", "runcall", "set_trace", "post_mortem", "help"] 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(os.path.join(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', '', '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 precedence # 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 == '' 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 do_bt = 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 is 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. 'bt' is an alias for this command.""" help_bt = help_w 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 is not 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` + ')')