Commit aa4485af authored by hjk's avatar hjk

Debugger: Rework Python Debugger

The (re-)enables basic stepping, data display, frame selection etc
for Python 2 and 3. Arguments passing, jump to line etc.
don't work yet.

Change-Id: I8af03e5905092360eb268ba3081a1236b1f8577f
Reviewed-by: default avatarChristian Stenger <christian.stenger@theqtcompany.com>
parent 9c27b9fd
import os
import re
import sys
import dis
import code
import glob
import base64
import signal
import string
import inspect
import traceback
import linecache
import fnmatch
def qdebug(cmd, args):
class QuitException(Exception):
pass
class Breakpoint:
"""Breakpoint class.
Breakpoints are indexed by number through bpbynumber and by
the file,line tuple using bplist. The former points to a
single instance of class Breakpoint. The latter points to a
list of such instances since there may be more than one
breakpoint per line.
"""
next = 1 # Next bp to be assigned
bplist = {} # indexed by (file, lineno) tuple
bpbynumber = [None] # Each entry is None or an instance of Bpt
# index 0 is unused, except for marking an
# effective break .... see effective()
def __init__(self, file, line, temporary=False, cond=None, funcname=None):
self.funcname = funcname
# Needed if funcname is not None.
self.func_first_executable_line = None
self.file = file # This better be in canonical form!
self.line = line
self.temporary = temporary
self.cond = cond
self.enabled = True
self.ignore = 0
self.hits = 0
self.number = Breakpoint.next
Breakpoint.next += 1
# Build the two lists
self.bpbynumber.append(self)
if (file, line) in self.bplist:
self.bplist[file, line].append(self)
else:
self.bplist[file, line] = [self]
def deleteMe(self):
index = (self.file, self.line)
self.bpbynumber[self.number] = None # No longer in list
self.bplist[index].remove(self)
if not self.bplist[index]:
# No more bp for this f:l combo
del self.bplist[index]
def enable(self):
self.enabled = True
def disable(self):
self.enabled = False
def __str__(self):
return 'breakpoint %s at %s:%s' % (self.number, self.file, self.line)
def checkfuncname(b, frame):
"""Check whether we should break here because of `b.funcname`."""
if not b.funcname:
# Breakpoint was set via line number.
if b.line != frame.f_lineno:
# Breakpoint was set at a line with a def statement and the function
# defined is called: don't break.
return False
return True
# Breakpoint set via function name.
if frame.f_code.co_name != b.funcname:
# It's not a function call, but rather execution of def statement.
return False
# We are in the right frame.
if not b.func_first_executable_line:
# The function is entered for the 1st time.
b.func_first_executable_line = frame.f_lineno
if b.func_first_executable_line != frame.f_lineno:
# But we are not at the first line number: don't break.
return False
return True
# Determines if there is an effective (active) breakpoint at this
# line of code. Returns breakpoint number or 0 if none
def effective(file, line, frame):
"""Determine which breakpoint for this file:line is to be acted upon.
Called only if we know there is a bpt at this
location. Returns breakpoint that was triggered and a flag
that indicates if it is ok to delete a temporary bp.
"""
possibles = Breakpoint.bplist[file, line]
for b in possibles:
if not b.enabled:
continue
if not checkfuncname(b, frame):
continue
# Count every hit when bp is enabled
b.hits += 1
if not b.cond:
# If unconditional, and ignoring go on to next, else break
if b.ignore > 0:
b.ignore -= 1
continue
else:
# breakpoint and marker that it's ok to delete if temporary
return (b, True)
else:
# Conditional bp.
# Ignore count applies only to those bpt hits where the
# condition evaluates to true.
try:
val = eval(b.cond, frame.f_globals, frame.f_locals)
if val:
if b.ignore > 0:
b.ignore -= 1
# continue
else:
return (b, True)
# else:
# continue
except:
# if eval fails, most conservative thing is to stop on
# breakpoint regardless of ignore count. Don't delete
# temporary, as another hint to user.
return (b, False)
return (None, None)
#__all__ = ["Dumper"]
def find_function(funcname, filename):
cre = re.compile(r'def\s+%s\s*[(]' % re.escape(funcname))
try:
fp = open(filename)
except OSError:
return None
# consumer of this info expects the first line to be 1
with fp:
for lineno, line in enumerate(fp, start=1):
if cre.match(line):
return funcname, filename, lineno
return None
def getsourcelines(obj):
lines, lineno = inspect.findsource(obj)
if inspect.isframe(obj) and obj.f_globals is obj.f_locals:
# must be a module frame: do not try to cut a block out of it
return lines, 1
elif inspect.ismodule(obj):
return lines, 1
return inspect.getblock(lines[lineno:]), lineno+1
def lasti2lineno(code, lasti):
linestarts = list(dis.findlinestarts(code))
linestarts.reverse()
for i, lineno in linestarts:
if lasti >= i:
return lineno
return 0
class _rstr(str):
"""String that doesn't quote its repr."""
def __repr__(self):
return self
class Dumper:
prompt = '(Cmd) '
identchars = string.ascii_letters + string.digits + '_'
lastcmd = ''
doc_leader = ""
doc_header = "Documented commands (type help <topic>):"
misc_header = "Miscellaneous help topics:"
undoc_header = "Undocumented commands:"
nohelp = "*** No help on %s"
use_rawinput = 1
def __init__(self, stdin=None, stdout=None):
self.skip = None
self.breaks = {}
self.fncache = {}
self.frame_returning = None
nosigint = False
if stdin is not None:
self.stdin = stdin
else:
self.stdin = sys.stdin
if stdout is not None:
self.stdout = stdout
else:
self.stdout = sys.stdout
self.cmdqueue = []
if stdout:
self.use_rawinput = 0
self.prompt = '(Pdb) '
self.aliases = {}
self.displaying = {}
self.mainpyfile = ''
self._wait_for_mainpyfile = False
self.tb_lineno = {}
# Try to load readline if it exists
try:
import readline
# remove some common file name delimiters
readline.set_completer_delims(' \t\n`@#$%^&*()=+[{]}\\|;:\'",<>?')
except ImportError:
pass
self.allow_kbdint = False
self.nosigint = nosigint
self.commands = {} # associates a command list to breakpoint numbers
self.commands_doprompt = {} # for each bp num, tells if the prompt
# must be disp. after execing the cmd list
self.commands_silent = {} # for each bp num, tells if the stack trace
# must be disp. after execing the cmd list
self.commands_bnum = None # The breakpoint number for which we are
# defining a list
def canonic(self, filename):
if filename == "<" + filename[1:-1] + ">":
return filename
canonic = self.fncache.get(filename)
if not canonic:
canonic = os.path.abspath(filename)
canonic = os.path.normcase(canonic)
self.fncache[filename] = canonic
return canonic
def reset(self):
import linecache
linecache.checkcache()
self.botframe = None
self._set_stopinfo(None, None)
self.forget()
def trace_dispatch(self, frame, event, arg):
if self.quitting:
return # None
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)
if event == 'c_call':
return self.trace_dispatch
if event == 'c_exception':
return self.trace_dispatch
if event == 'c_return':
return self.trace_dispatch
print('Bdb.dispatch: unknown debugging event:', repr(event))
return self.trace_dispatch
def dispatch_line(self, frame):
if self.stop_here(frame) or self.break_here(frame):
self.user_line(frame)
if self.quitting: raise QuitException
return self.trace_dispatch
def dispatch_call(self, frame, arg):
# XXX 'arg' is no longer used
if self.botframe is None:
# First call of dispatch since reset()
self.botframe = frame.f_back # (CT) Note that this may also be None!
return self.trace_dispatch
if not (self.stop_here(frame) or self.break_anywhere(frame)):
# No need to trace this function
return # None
# Ignore call events in generator except when stepping.
if self.stopframe and frame.f_code.co_flags & inspect.CO_GENERATOR:
return self.trace_dispatch
self.user_call(frame, arg)
if self.quitting: raise QuitException
return self.trace_dispatch
def dispatch_return(self, frame, arg):
if self.stop_here(frame) or frame == self.returnframe:
# Ignore return events in generator except when stepping.
if self.stopframe and frame.f_code.co_flags & inspect.CO_GENERATOR:
return self.trace_dispatch
try:
self.frame_returning = frame
self.user_return(frame, arg)
finally:
self.frame_returning = None
if self.quitting: raise QuitException
# The user issued a 'next' or 'until' command.
if self.stopframe is frame and self.stoplineno != -1:
self._set_stopinfo(None, None)
return self.trace_dispatch
def dispatch_exception(self, frame, arg):
if self.stop_here(frame):
# When stepping with next/until/return in a generator frame, skip
# the internal StopIteration exception (with no traceback)
# triggered by a subiterator run with the 'yield from' statement.
if not (frame.f_code.co_flags & inspect.CO_GENERATOR
and arg[0] is StopIteration and arg[2] is None):
self.user_exception(frame, arg)
if self.quitting: raise QuitException
# Stop at the StopIteration or GeneratorExit exception when the user
# has set stopframe in a generator by issuing a return command, or a
# next/until command at the last statement in the generator before the
# exception.
elif (self.stopframe and frame is not self.stopframe
and self.stopframe.f_code.co_flags & inspect.CO_GENERATOR
and arg[0] in (StopIteration, GeneratorExit)):
self.user_exception(frame, arg)
if self.quitting: raise QuitException
return self.trace_dispatch
# Normally derived classes don't override the following
# methods, but they may if they want to redefine the
# definition of stopping and breakpoints.
def is_skipped_module(self, module_name):
for pattern in self.skip:
if fnmatch.fnmatch(module_name, pattern):
return True
return False
def stop_here(self, frame):
# (CT) stopframe may now also be None, see dispatch_call.
# (CT) the former test for None is therefore removed from here.
if self.skip and \
self.is_skipped_module(frame.f_globals.get('__name__')):
return False
if frame is self.stopframe:
if self.stoplineno == -1:
return False
return frame.f_lineno >= self.stoplineno
if not self.stopframe:
return True
return False
def break_here(self, frame):
filename = self.canonic(frame.f_code.co_filename)
if filename not in self.breaks:
return False
lineno = frame.f_lineno
if lineno not in self.breaks[filename]:
# The line itself has no breakpoint, but maybe the line is the
# first line of a function with breakpoint set by function name.
lineno = frame.f_code.co_firstlineno
if lineno not in self.breaks[filename]:
return False
# flag says ok to delete temp. bp
(bp, flag) = effective(filename, lineno, frame)
if bp:
self.currentbp = bp.number
if (flag and bp.temporary):
self.do_clear(str(bp.number))
return True
else:
return False
def break_anywhere(self, frame):
return self.canonic(frame.f_code.co_filename) in self.breaks
def _set_stopinfo(self, stopframe, returnframe, stoplineno=0):
self.stopframe = stopframe
self.returnframe = returnframe
self.quitting = False
# stoplineno >= 0 means: stop at line >= the stoplineno
# stoplineno -1 means: don't stop at all
self.stoplineno = stoplineno
# Derived classes and clients can call the following methods
# to affect the stepping state.
def set_until(self, frame, lineno=None):
"""Stop when the line with the line no greater than the current one is
reached or when returning from current frame"""
# the name "until" is borrowed from gdb
if lineno is None:
lineno = frame.f_lineno + 1
self._set_stopinfo(frame, frame, lineno)
def set_step(self):
"""Stop after one line of code."""
# Issue #13183: pdb skips frames after hitting a breakpoint and running
# step commands.
# Restore the trace function in the caller (that may not have been set
# for performance reasons) when returning from the current frame.
if self.frame_returning:
caller_frame = self.frame_returning.f_back
if caller_frame and not caller_frame.f_trace:
caller_frame.f_trace = self.trace_dispatch
self._set_stopinfo(None, None)
def set_next(self, frame):
"""Stop on the next line in or below the given frame."""
self._set_stopinfo(frame, None)
def set_return(self, frame):
"""Stop when returning from the given frame."""
if frame.f_code.co_flags & inspect.CO_GENERATOR:
self._set_stopinfo(frame, None, -1)
else:
self._set_stopinfo(frame.f_back, frame)
def set_trace(self, frame=None):
"""Start debugging from `frame`.
If frame is not specified, debugging starts from caller's frame.
"""
if frame is None:
frame = sys._getframe().f_back
self.reset()
while frame:
frame.f_trace = self.trace_dispatch
self.botframe = frame
frame = frame.f_back
self.set_step()
sys.settrace(self.trace_dispatch)
def set_continue(self):
# Don't stop except at breakpoints or when finished
self._set_stopinfo(self.botframe, None, -1)
if not self.breaks:
# no breakpoints; run without debugger overhead
sys.settrace(None)
frame = sys._getframe().f_back
while frame and frame is not self.botframe:
del frame.f_trace
frame = frame.f_back
def set_quit(self):
self.stopframe = self.botframe
self.returnframe = None
self.quitting = True
sys.settrace(None)
# Derived classes and clients can call the following methods
# to manipulate breakpoints. These methods return an
# error message if something went wrong, None if all is well.
# Set_break prints out the breakpoint line and file:lineno.
# Call self.get_*break*() to see the breakpoints or better
# for bp in Breakpoint.bpbynumber: if bp: bp.bpprint().
def set_break(self, filename, lineno, temporary=False, cond=None,
funcname=None):
filename = self.canonic(filename)
import linecache # Import as late as possible
line = linecache.getline(filename, lineno)
if not line:
return 'Line %s:%d does not exist' % (filename, lineno)
list = self.breaks.setdefault(filename, [])
if lineno not in list:
list.append(lineno)
bp = Breakpoint(filename, lineno, temporary, cond, funcname)
def _prune_breaks(self, filename, lineno):
if (filename, lineno) not in Breakpoint.bplist:
self.breaks[filename].remove(lineno)
if not self.breaks[filename]:
del self.breaks[filename]
def clear_break(self, filename, lineno):
filename = self.canonic(filename)
if filename not in self.breaks:
return 'There are no breakpoints in %s' % filename
if lineno not in self.breaks[filename]:
return 'There is no breakpoint at %s:%d' % (filename, lineno)
# If there's only one bp in the list for that file,line
# pair, then remove the breaks entry
for bp in Breakpoint.bplist[filename, lineno][:]:
bp.deleteMe()
self._prune_breaks(filename, lineno)
def clear_bpbynumber(self, arg):
try:
bp = self.get_bpbynumber(arg)
except ValueError as err:
return str(err)
bp.deleteMe()
self._prune_breaks(bp.file, bp.line)
def clear_all_file_breaks(self, filename):
filename = self.canonic(filename)
if filename not in self.breaks:
return 'There are no breakpoints in %s' % filename
for line in self.breaks[filename]:
blist = Breakpoint.bplist[filename, line]
for bp in blist:
bp.deleteMe()
del self.breaks[filename]
def clear_all_breaks(self):
if not self.breaks:
return 'There are no breakpoints'
for bp in Breakpoint.bpbynumber:
if bp:
bp.deleteMe()
self.breaks = {}
def get_bpbynumber(self, arg):
if not arg:
raise ValueError('Breakpoint number expected')
try:
number = int(arg)
except ValueError:
raise ValueError('Non-numeric breakpoint number %s' % arg)
try:
bp = Breakpoint.bpbynumber[number]
except IndexError:
raise ValueError('Breakpoint number %d out of range' % number)
if bp is None:
raise ValueError('Breakpoint %d already deleted' % number)
return bp
def get_break(self, filename, lineno):
filename = self.canonic(filename)
return filename in self.breaks and \
lineno in self.breaks[filename]
def get_breaks(self, filename, lineno):
filename = self.canonic(filename)
return filename in self.breaks and \
lineno in self.breaks[filename] and \
Breakpoint.bplist[filename, lineno] or []
def get_file_breaks(self, filename):
filename = self.canonic(filename)
if filename in self.breaks:
return self.breaks[filename]
else:
return []
def get_all_breaks(self):
return self.breaks
# Derived classes and clients can call the following method
# to get a data structure representing a stack trace.
def get_stack(self, f, t):
stack = []
if t and t.tb_frame is f:
t = t.tb_next
while f is not None:
stack.append((f, f.f_lineno))
if f is self.botframe:
break
f = f.f_back
stack.reverse()
i = max(0, len(stack) - 1)
while t is not None:
stack.append((t.tb_frame, t.tb_lineno))
t = t.tb_next
if f is None:
i = max(0, len(stack) - 1)
return stack, i
def format_stack_entry(self, frame_lineno, lprefix=': '):
import linecache
#import reprlib
frame, lineno = frame_lineno
filename = self.canonic(frame.f_code.co_filename)
s = '%s(%r)' % (filename, lineno)
if frame.f_code.co_name:
s += frame.f_code.co_name
else:
s += "<lambda>"
if '__args__' in frame.f_locals:
args = frame.f_locals['__args__']
else:
args = None
#if args:
# s += reprlib.repr(args)
#else:
s += '(...)'
#if '__return__' in frame.f_locals:
# rv = frame.f_locals['__return__']
# s += '->'
# s += reprlib.repr(rv)
line = linecache.getline(filename, lineno, frame.f_globals)
if line:
s += lprefix + line.strip()
return s
# The following methods can be called by clients to use
# a debugger to debug a statement or an expression.
# Both can be given as a string, or a code object.
def run(self, cmd, globals=None, locals=None):
if globals is None:
import __main__
globals = __main__.__dict__
if locals is None:
locals = globals
self.reset()
if isinstance(cmd, str):
cmd = compile(cmd, "<string>", "exec")
sys.settrace(self.trace_dispatch)
try:
exec(cmd, globals, locals)
except QuitException: