debugger.py

"""Debug user code with a GUI interface to a subclass of bdb.Bdb.

The Idb idb and Debugger gui instances each need a reference to each
other or to an rpc proxy for each other.

If IDLE is started with '-n', so that user code and idb both run in the
IDLE process, Debugger is called without an idb. Debugger.__init__
calls Idb with its incomplete self. Idb.__init__ stores gui and gui
then stores idb.

If IDLE is started normally, so that user code executes in a separate
process, debugger_r.start_remote_debugger is called, executing in the
IDLE process. It calls 'start the debugger' in the remote process,
which calls Idb with a gui proxy. Then Debugger is called in the IDLE
for more.
"""

importbdb
importos

fromtkinterimport*
fromtkinter.ttkimportFrame, Scrollbar

fromidlelibimportmacosx
fromidlelib.scrolledlistimportScrolledList
fromidlelib.windowimportListedToplevel


classIdb(bdb.Bdb):
"Supply user_line and user_exception functions for Bdb."

def__init__(self, gui):
self.gui=gui# An instance of Debugger or proxy thereof.
super().__init__()

defuser_line(self, frame):
"""Handle a user stopping or breaking at a line.

 Convert frame to a string and send it to gui.
 """
if_in_rpc_code(frame):
self.set_step()
return
message=_frame2message(frame)
try:
self.gui.interaction(message, frame)
exceptTclError: # When closing debugger window with [x] in 3.x
pass

defuser_exception(self, frame, exc_info):
"""Handle an the occurrence of an exception."""
if_in_rpc_code(frame):
self.set_step()
return
message=_frame2message(frame)
self.gui.interaction(message, frame, exc_info)

def_in_rpc_code(frame):
"Determine if debugger is within RPC code."
ifframe.f_code.co_filename.count('rpc.py'):
returnTrue# Skip this frame.
else:
prev_frame=frame.f_back
ifprev_frameisNone:
returnFalse
prev_name=prev_frame.f_code.co_filename
if'idlelib'inprev_nameand'debugger'inprev_name:
# catch both idlelib/debugger.py and idlelib/debugger_r.py
# on both Posix and Windows
returnFalse
return_in_rpc_code(prev_frame)

def_frame2message(frame):
"""Return a message string for frame."""
code=frame.f_code
filename=code.co_filename
lineno=frame.f_lineno
basename=os.path.basename(filename)
message=f"{basename}:{lineno}"
ifcode.co_name!="?":
message=f"{message}: {code.co_name}()"
returnmessage


classDebugger:
"""The debugger interface.

 This class handles the drawing of the debugger window and
 the interactions with the underlying debugger session.
 """
vstack=None
vsource=None
vlocals=None
vglobals=None
stackviewer=None
localsviewer=None
globalsviewer=None

def__init__(self, pyshell, idb=None):
"""Instantiate and draw a debugger window.

 :param pyshell: An instance of the PyShell Window
 :type pyshell: :class:`idlelib.pyshell.PyShell`

 :param idb: An instance of the IDLE debugger (optional)
 :type idb: :class:`idlelib.debugger.Idb`
 """
ifidbisNone:
idb=Idb(self)
self.pyshell=pyshell
self.idb=idb# If passed, a proxy of remote instance.
self.frame=None
self.make_gui()
self.interacting=False
self.nesting_level=0

defrun(self, *args):
"""Run the debugger."""
# Deal with the scenario where we've already got a program running
# in the debugger and we want to start another. If that is the case,
# our second 'run' was invoked from an event dispatched not from
# the main event loop, but from the nested event loop in 'interaction'
# below. So our stack looks something like this:
# outer main event loop
# run()
# <running program with traces>
# callback to debugger's interaction()
# nested event loop
# run() for second command
#
# This kind of nesting of event loops causes all kinds of problems
# (see e.g. issue #24455) especially when dealing with running as a
# subprocess, where there's all kinds of extra stuff happening in
# there - insert a traceback.print_stack() to check it out.
#
# By this point, we've already called restart_subprocess() in
# ScriptBinding. However, we also need to unwind the stack back to
# that outer event loop. To accomplish this, we:
# - return immediately from the nested run()
# - abort_loop ensures the nested event loop will terminate
# - the debugger's interaction routine completes normally
# - the restart_subprocess() will have taken care of stopping
# the running program, which will also let the outer run complete
#
# That leaves us back at the outer main event loop, at which point our
# after event can fire, and we'll come back to this routine with a
# clean stack.
ifself.nesting_level>0:
self.abort_loop()
self.root.after(100, lambda: self.run(*args))
return
try:
self.interacting=True
returnself.idb.run(*args)
finally:
self.interacting=False

defclose(self, event=None):
"""Close the debugger and window."""
try:
self.quit()
exceptException:
pass
ifself.interacting:
self.top.bell()
return
ifself.stackviewer:
self.stackviewer.close(); self.stackviewer=None
# Clean up pyshell if user clicked debugger control close widget.
# (Causes a harmless extra cycle through close_debugger() if user
# toggled debugger from pyshell Debug menu)
self.pyshell.close_debugger()
# Now close the debugger control window....
self.top.destroy()

defmake_gui(self):
"""Draw the debugger gui on the screen."""
pyshell=self.pyshell
self.flist=pyshell.flist
self.root=root=pyshell.root
self.top=top=ListedToplevel(root)
self.top.wm_title("Debug Control")
self.top.wm_iconname("Debug")
top.wm_protocol("WM_DELETE_WINDOW", self.close)
self.top.bind("<Escape>", self.close)

self.bframe=bframe=Frame(top)
self.bframe.pack(anchor="w")
self.buttons=bl= []

self.bcont=b=Button(bframe, text="Go", command=self.cont)
bl.append(b)
self.bstep=b=Button(bframe, text="Step", command=self.step)
bl.append(b)
self.bnext=b=Button(bframe, text="Over", command=self.next)
bl.append(b)
self.bret=b=Button(bframe, text="Out", command=self.ret)
bl.append(b)
self.bret=b=Button(bframe, text="Quit", command=self.quit)
bl.append(b)

forbinbl:
b.configure(state="disabled")
b.pack(side="left")

self.cframe=cframe=Frame(bframe)
self.cframe.pack(side="left")

ifnotself.vstack:
self.__class__.vstack=BooleanVar(top)
self.vstack.set(1)
self.bstack=Checkbutton(cframe,
text="Stack", command=self.show_stack, variable=self.vstack)
self.bstack.grid(row=0, column=0)
ifnotself.vsource:
self.__class__.vsource=BooleanVar(top)
self.bsource=Checkbutton(cframe,
text="Source", command=self.show_source, variable=self.vsource)
self.bsource.grid(row=0, column=1)
ifnotself.vlocals:
self.__class__.vlocals=BooleanVar(top)
self.vlocals.set(1)
self.blocals=Checkbutton(cframe,
text="Locals", command=self.show_locals, variable=self.vlocals)
self.blocals.grid(row=1, column=0)
ifnotself.vglobals:
self.__class__.vglobals=BooleanVar(top)
self.bglobals=Checkbutton(cframe,
text="Globals", command=self.show_globals, variable=self.vglobals)
self.bglobals.grid(row=1, column=1)

self.status=Label(top, anchor="w")
self.status.pack(anchor="w")
self.error=Label(top, anchor="w")
self.error.pack(anchor="w", fill="x")
self.errorbg=self.error.cget("background")

self.fstack=Frame(top, height=1)
self.fstack.pack(expand=1, fill="both")
self.flocals=Frame(top)
self.flocals.pack(expand=1, fill="both")
self.fglobals=Frame(top, height=1)
self.fglobals.pack(expand=1, fill="both")

ifself.vstack.get():
self.show_stack()
ifself.vlocals.get():
self.show_locals()
ifself.vglobals.get():
self.show_globals()

definteraction(self, message, frame, info=None):
self.frame=frame
self.status.configure(text=message)

ifinfo:
type, value, tb=info
try:
m1=type.__name__
exceptAttributeError:
m1="%s"%str(type)
ifvalueisnotNone:
try:
# TODO redo entire section, tries not needed.
m1=f"{m1}: {value}"
except:
pass
bg="yellow"
else:
m1=""
tb=None
bg=self.errorbg
self.error.configure(text=m1, background=bg)

sv=self.stackviewer
ifsv:
stack, i=self.idb.get_stack(self.frame, tb)
sv.load_stack(stack, i)

self.show_variables(1)

ifself.vsource.get():
self.sync_source_line()

forbinself.buttons:
b.configure(state="normal")

self.top.wakeup()
# Nested main loop: Tkinter's main loop is not reentrant, so use
# Tcl's vwait facility, which reenters the event loop until an
# event handler sets the variable we're waiting on.
self.nesting_level+=1
self.root.tk.call('vwait', '::idledebugwait')
self.nesting_level-=1

forbinself.buttons:
b.configure(state="disabled")
self.status.configure(text="")
self.error.configure(text="", background=self.errorbg)
self.frame=None

defsync_source_line(self):
frame=self.frame
ifnotframe:
return
filename, lineno=self.__frame2fileline(frame)
iffilename[:1] +filename[-1:] !="<>"andos.path.exists(filename):
self.flist.gotofileline(filename, lineno)

def__frame2fileline(self, frame):
code=frame.f_code
filename=code.co_filename
lineno=frame.f_lineno
returnfilename, lineno

defcont(self):
self.idb.set_continue()
self.abort_loop()

defstep(self):
self.idb.set_step()
self.abort_loop()

defnext(self):
self.idb.set_next(self.frame)
self.abort_loop()

defret(self):
self.idb.set_return(self.frame)
self.abort_loop()

defquit(self):
self.idb.set_quit()
self.abort_loop()

defabort_loop(self):
self.root.tk.call('set', '::idledebugwait', '1')

defshow_stack(self):
ifnotself.stackviewerandself.vstack.get():
self.stackviewer=sv=StackViewer(self.fstack, self.flist, self)
ifself.frame:
stack, i=self.idb.get_stack(self.frame, None)
sv.load_stack(stack, i)
else:
sv=self.stackviewer
ifsvandnotself.vstack.get():
self.stackviewer=None
sv.close()
self.fstack['height'] =1

defshow_source(self):
ifself.vsource.get():
self.sync_source_line()

defshow_frame(self, stackitem):
self.frame=stackitem[0] # lineno is stackitem[1]
self.show_variables()

defshow_locals(self):
lv=self.localsviewer
ifself.vlocals.get():
ifnotlv:
self.localsviewer=NamespaceViewer(self.flocals, "Locals")
else:
iflv:
self.localsviewer=None
lv.close()
self.flocals['height'] =1
self.show_variables()

defshow_globals(self):
gv=self.globalsviewer
ifself.vglobals.get():
ifnotgv:
self.globalsviewer=NamespaceViewer(self.fglobals, "Globals")
else:
ifgv:
self.globalsviewer=None
gv.close()
self.fglobals['height'] =1
self.show_variables()

defshow_variables(self, force=0):
lv=self.localsviewer
gv=self.globalsviewer
frame=self.frame
ifnotframe:
ldict=gdict=None
else:
ldict=frame.f_locals
gdict=frame.f_globals
iflvandgvandldictisgdict:
ldict=None
iflv:
lv.load_dict(ldict, force, self.pyshell.interp.rpcclt)
ifgv:
gv.load_dict(gdict, force, self.pyshell.interp.rpcclt)

defset_breakpoint(self, filename, lineno):
"""Set a filename-lineno breakpoint in the debugger.

 Called from self.load_breakpoints and EW.setbreakpoint
 """
self.idb.set_break(filename, lineno)

defclear_breakpoint(self, filename, lineno):
self.idb.clear_break(filename, lineno)

defclear_file_breaks(self, filename):
self.idb.clear_all_file_breaks(filename)

defload_breakpoints(self):
"""Load PyShellEditorWindow breakpoints into subprocess debugger."""
foreditwininself.pyshell.flist.inversedict:
filename=editwin.io.filename
try:
forlinenoineditwin.breakpoints:
self.set_breakpoint(filename, lineno)
exceptAttributeError:
continue


classStackViewer(ScrolledList):
"Code stack viewer for debugger GUI."

def__init__(self, master, flist, gui):
ifmacosx.isAquaTk():
# At least on with the stock AquaTk version on OSX 10.4 you'll
# get a shaking GUI that eventually kills IDLE if the width
# argument is specified.
ScrolledList.__init__(self, master)
else:
ScrolledList.__init__(self, master, width=80)
self.flist=flist
self.gui=gui
self.stack= []

defload_stack(self, stack, index=None):
self.stack=stack
self.clear()
foriinrange(len(stack)):
frame, lineno=stack[i]
try:
modname=frame.f_globals["__name__"]
except:
modname="?"
code=frame.f_code
filename=code.co_filename
funcname=code.co_name
importlinecache
sourceline=linecache.getline(filename, lineno)
sourceline=sourceline.strip()
iffuncnamein ("?", "", None):
item="%s, line %d: %s"% (modname, lineno, sourceline)
else:
item="%s.%s(), line %d: %s"% (modname, funcname,
lineno, sourceline)
ifi==index:
item="> "+item
self.append(item)
ifindexisnotNone:
self.select(index)

defpopup_event(self, event):
"Override base method."
ifself.stack:
returnScrolledList.popup_event(self, event)

deffill_menu(self):
"Override base method."
menu=self.menu
menu.add_command(label="Go to source line",
command=self.goto_source_line)
menu.add_command(label="Show stack frame",
command=self.show_stack_frame)

defon_select(self, index):
"Override base method."
if0<=index<len(self.stack):
self.gui.show_frame(self.stack[index])

defon_double(self, index):
"Override base method."
self.show_source(index)

defgoto_source_line(self):
index=self.listbox.index("active")
self.show_source(index)

defshow_stack_frame(self):
index=self.listbox.index("active")
if0<=index<len(self.stack):
self.gui.show_frame(self.stack[index])

defshow_source(self, index):
ifnot (0<=index<len(self.stack)):
return
frame, lineno=self.stack[index]
code=frame.f_code
filename=code.co_filename
ifos.path.isfile(filename):
edit=self.flist.open(filename)
ifedit:
edit.gotoline(lineno)


classNamespaceViewer:
"Global/local namespace viewer for debugger GUI."

def__init__(self, master, title, odict=None): # XXX odict never passed.
width=0
height=40
ifodict:
height=20*len(odict) # XXX 20 == observed height of Entry widget
self.master=master
self.title=title
importreprlib
self.repr=reprlib.Repr()
self.repr.maxstring=60
self.repr.maxother=60
self.frame=frame=Frame(master)
self.frame.pack(expand=1, fill="both")
self.label=Label(frame, text=title, borderwidth=2, relief="groove")
self.label.pack(fill="x")
self.vbar=vbar=Scrollbar(frame, name="vbar")
vbar.pack(side="right", fill="y")
self.canvas=canvas=Canvas(frame,
height=min(300, max(40, height)),
scrollregion=(0, 0, width, height))
canvas.pack(side="left", fill="both", expand=1)
vbar["command"] =canvas.yview
canvas["yscrollcommand"] =vbar.set
self.subframe=subframe=Frame(canvas)
self.sfid=canvas.create_window(0, 0, window=subframe, anchor="nw")
self.load_dict(odict)

prev_odict=-1# Needed for initial comparison below.

defload_dict(self, odict, force=0, rpc_client=None):
ifodictisself.prev_odictandnotforce:
return
subframe=self.subframe
frame=self.frame
forcinlist(subframe.children.values()):
c.destroy()
self.prev_odict=None
ifnotodict:
l=Label(subframe, text="None")
l.grid(row=0, column=0)
else:
#names = sorted(dict)
#
# Because of (temporary) limitations on the dict_keys type (not yet
# public or pickleable), have the subprocess to send a list of
# keys, not a dict_keys object. sorted() will take a dict_keys
# (no subprocess) or a list.
#
# There is also an obscure bug in sorted(dict) where the
# interpreter gets into a loop requesting non-existing dict[0],
# dict[1], dict[2], etc from the debugger_r.DictProxy.
# TODO recheck above; see debugger_r 159ff, debugobj 60.
keys_list=odict.keys()
names=sorted(keys_list)

row=0
fornameinnames:
value=odict[name]
svalue=self.repr.repr(value) # repr(value)
# Strip extra quotes caused by calling repr on the (already)
# repr'd value sent across the RPC interface:
ifrpc_client:
svalue=svalue[1:-1]
l=Label(subframe, text=name)
l.grid(row=row, column=0, sticky="nw")
l=Entry(subframe, width=0, borderwidth=0)
l.insert(0, svalue)
l.grid(row=row, column=1, sticky="nw")
row=row+1
self.prev_odict=odict
# XXX Could we use a <Configure> callback for the following?
subframe.update_idletasks() # Alas!
width=subframe.winfo_reqwidth()
height=subframe.winfo_reqheight()
canvas=self.canvas
self.canvas["scrollregion"] = (0, 0, width, height)
ifheight>300:
canvas["height"] =300
frame.pack(expand=1)
else:
canvas["height"] =height
frame.pack(expand=0)

defclose(self):
self.frame.destroy()


if__name__=="__main__":
fromunittestimportmain
main('idlelib.idle_test.test_debugger', verbosity=2, exit=False)

# TODO: htest?