# -*- coding: utf-8 -*- # # Copyright (c) 2009- Spyder Kernels Contributors # # Licensed under the terms of the MIT License # (see spyder_kernels/__init__.py for details) """Spyder debugger.""" import ast import bdb import builtins from contextlib import contextmanager import logging import os import sys import traceback import threading from collections import namedtuple from functools import lru_cache from IPython.core.autocall import ZMQExitAutocall from IPython.core.debugger import Pdb as ipyPdb from IPython.core.inputtransformer2 import TransformerManager import spyder_kernels from spyder_kernels.comms.commbase import stacksummary_to_json from spyder_kernels.comms.frontendcomm import CommError, frontend_request from spyder_kernels.customize.utils import ( path_is_library, capture_last_Expr, exec_encapsulate_locals ) logger = logging.getLogger(__name__) class DebugWrapper: """ Notifies the frontend when debugging starts/stops """ def __init__(self, pdb_obj): self.pdb_obj = pdb_obj self._cleanup = True def __enter__(self): """ Debugging starts. """ shell = self.pdb_obj.shell if shell.pdb_session == self.pdb_obj: self._cleanup = False else: shell.add_pdb_session(self.pdb_obj) self._cleanup = True def __exit__(self, exc_type, exc_val, exc_tb): """ Debugging ends. """ if self._cleanup: self.pdb_obj.shell.remove_pdb_session(self.pdb_obj) class SpyderPdb(ipyPdb): """ Extends Pdb to add features: - Process IPython magics. - Accepts multiline input. - Better interrupt signal handling. - Option to skip libraries while stepping. - Add completion to non-command code. """ def __init__(self, completekey='tab', stdin=None, stdout=None, skip=None, nosigint=False): """Init Pdb.""" self.curframe_locals = None # Only set to true when calling debugfile self.continue_if_has_breakpoints = False self.pdb_ignore_lib = False self.pdb_execute_events = False self.pdb_use_exclamation_mark = False self.pdb_publish_stack = False self._exclamation_warning_printed = False self.pdb_stop_first_line = True self._disable_next_stack_entry = False super(SpyderPdb, self).__init__() # content of tuple: (filename, line number) self._previous_step = None # Don't report hidden frames for IPython 7.24+. This attribute # has no effect in previous versions. self.report_skipped = False # Keep track of remote filename self.remote_filename = None # Needed to know which namespace to show (user or current frame) # Line received from the frontend self._cmd_input_line = None # Disable sigint so we can do it ourselves self.nosigint = True # Keep track of interrupting state to avoid several interruptions self.interrupting = False # Should the frontend force go to the current line? self._request_where = False # Turn off IPython's debugger skip funcionality by default because # it makes our debugger quite slow. It's also important to remark # that this functionality doesn't do anything on its own. Users # need to mark what frames they want to skip for it to be useful. # So, we hope that knowledgeable users will find that they need to # enable it in Spyder. # Fixes spyder-ide/spyder#20639. self._predicates["debuggerskip"] = False # Save seen files inodes self._canonic_inode_to_filename = {} self._canonic_filename_to_inode = {} # --- Methods overriden for code execution def print_exclamation_warning(self): """Print pdb warning for exclamation mark.""" if not self._exclamation_warning_printed: print("Warning: The exclamation mark option is enabled. " "Please use '!' as a prefix for Pdb commands.") self._exclamation_warning_printed = True def default(self, line): """ Default way of running pdb statment. """ execute_events = self.pdb_execute_events if line[:1] == '!': line = line[1:] elif self.pdb_use_exclamation_mark: self.print_exclamation_warning() self.error("Unknown command '" + line.split()[0] + "'") return # Replace %debug magic in the debugger if line.startswith("%debug") or line.startswith("%%debug"): cmd, arg, _ = self.parseline(line.lstrip("%")) if cmd == "debug": return self.do_debug(arg) local_ns = self.curframe_locals global_ns = self.curframe.f_globals if self.pdb_use_exclamation_mark: # Find pdb commands executed without ! cmd, arg, line = self.parseline(line) if cmd: cmd_in_namespace = ( cmd in global_ns or cmd in local_ns or cmd in builtins.__dict__ ) # Special case for quit and exit if cmd in ("quit", "exit"): if cmd in global_ns and isinstance( global_ns[cmd], ZMQExitAutocall): # Use the pdb call cmd_in_namespace = False cmd_func = getattr(self, 'do_' + cmd, None) is_pdb_cmd = cmd_func is not None # Look for assignment is_assignment = False try: for node in ast.walk(ast.parse(line)): if isinstance(node, ast.Assign): is_assignment = True break except SyntaxError: pass if is_pdb_cmd: if not cmd_in_namespace and not is_assignment: # This is a pdb command without the '!' prefix. self.lastcmd = line return cmd_func(arg) else: # The pdb command is masked by something self.print_exclamation_warning() try: is_magic = line.startswith("%") line = TransformerManager().transform_cell(line) save_stdout = sys.stdout save_stdin = sys.stdin save_displayhook = sys.displayhook try: sys.stdin = self.stdin sys.stdout = self.stdout sys.displayhook = self.displayhook if execute_events: self.shell.events.trigger('pre_execute') code_ast = ast.parse(line) if line.rstrip()[-1:] == ";": # Supress output with ; capture_last_expression = False else: code_ast, capture_last_expression = capture_last_Expr( code_ast, "_spyderpdb_out", global_ns) if is_magic: # Magics like runcell use and modify local_ns. # But the locals() dict can not be directly modified when # encapsulated. Therefore they must encapsulate the locals # themselves (see code_runner.py). exec(compile(code_ast, "", "exec"), global_ns, local_ns) else: exec_encapsulate_locals(code_ast, global_ns, local_ns) if capture_last_expression: out = global_ns.pop("_spyderpdb_out", None) if out is not None: sys.stdout.flush() sys.stderr.flush() try: frontend_request(blocking=False).show_pdb_output( repr(out)) except (CommError, TimeoutError): # Fallback print("pdb out> ", repr(out)) finally: if execute_events: self.shell.events.trigger('post_execute') sys.stdout = save_stdout sys.stdin = save_stdin sys.displayhook = save_displayhook except BaseException: exc_info = sys.exc_info()[:2] self.error( traceback.format_exception_only(*exc_info)[-1].strip()) # --- Methods overriden for signal handling def interrupt(self): """Stop debugger on next instruction.""" self.interrupting = True self.message("\nProgram interrupted. (Use 'cont' to resume).") self.set_step() def set_trace(self, frame=None): """Register that debugger is tracing.""" self.shell.add_pdb_session(self) super(SpyderPdb, self).set_trace(frame) def set_quit(self): """Register that debugger is not tracing.""" self.shell.remove_pdb_session(self) super(SpyderPdb, self).set_quit() def interaction(self, frame, traceback): """ Called when a user interaction is required. """ with DebugWrapper(self): # Wrapp in case the frontend was not notified, e.g. postmortem return super(SpyderPdb, self).interaction( frame, traceback) def print_stack_entry(self, *args, **kwargs): """Disable printing stack entry if requested.""" if self._disable_next_stack_entry: self._disable_next_stack_entry = False return return super().print_stack_entry(*args, **kwargs) # --- Methods overriden for skipping libraries def stop_here(self, frame): """Check if pdb should stop here.""" # Never stop if we are continuing unless there is a breakpoint if self.stopframe == self.botframe and self.stoplineno == -1: return False if self.continue_if_has_breakpoints and self.should_continue(frame): self.set_continue() return False if ( frame is not None and "__tracebackhide__" in frame.f_locals and frame.f_locals["__tracebackhide__"] == "__pdb_exit__" ): self.onecmd('exit') return False if not super().stop_here(frame): return False if frame is self.stopframe: return True filename = frame.f_code.co_filename if filename.startswith('<'): # This is not a file return True if self.pdb_ignore_lib and path_is_library(filename): return False if self.skip_hidden and os.path.dirname(spyder_kernels.__file__) in filename: # This is spyder-kernels internals return False return True def should_continue(self, frame): """ Jump to first breakpoint if needed. Fixes spyder-ide/spyder#2034 """ if not self.continue_if_has_breakpoints: # This was disabled return False self.continue_if_has_breakpoints = False # Get all breakpoints for the file we're going to debug if not frame: # We are not debugging, return. Solves spyder-ide/spyder#10290 return False lineno = frame.f_lineno breaks = self.get_file_breaks(frame.f_code.co_filename) # Do 'continue' if the first breakpoint is *not* placed # where the debugger is going to land. # Fixes spyder-ide/spyder#4681 if self.pdb_stop_first_line: return breaks and lineno < breaks[0] # The breakpoint could be in another file. return not (breaks and lineno >= breaks[0]) def do_where(self, arg): """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. Take a number as argument as an (optional) number of context line to print""" self._request_where = True return super(SpyderPdb, self).do_where(arg) do_w = do_where do_bt = do_where # --- Method defined by us to respond to ipython complete protocol def do_complete(self, code, cursor_pos): """ Respond to a complete request. """ if self.pdb_use_exclamation_mark: return self._complete_exclamation(code, cursor_pos) else: return self._complete_default(code, cursor_pos) def _complete_default(self, code, cursor_pos): """ Respond to a complete request if not pdb_use_exclamation_mark. """ if cursor_pos is None: cursor_pos = len(code) # Get text to complete text = code[:cursor_pos].split(' ')[-1] # Choose Pdb function to complete, based on cmd.py origline = code line = origline.lstrip() if not line: # Nothing to complete return stripped = len(origline) - len(line) begidx = cursor_pos - len(text) - stripped endidx = cursor_pos - stripped compfunc = None ipython_do_complete = True if begidx > 0: # This could be after a Pdb command cmd, args, _ = self.parseline(line) if cmd != '': try: # Function to complete Pdb command arguments compfunc = getattr(self, 'complete_' + cmd) # Don't call ipython do_complete for commands ipython_do_complete = False except AttributeError: pass elif line[0] != '!': # This could be a Pdb command compfunc = self.completenames def is_name_or_composed(text): if not text or text[0] == '.': return False # We want to keep value.subvalue return text.replace('.', '').isidentifier() while text and not is_name_or_composed(text): text = text[1:] begidx += 1 matches = [] if compfunc: matches = compfunc(text, line, begidx, endidx) cursor_start = cursor_pos - len(text) if ipython_do_complete: # Make complete call with current frame if self.curframe: if self.curframe_locals: Frame = namedtuple("Frame", ["f_locals", "f_globals"]) frame = Frame(self.curframe_locals, self.curframe.f_globals) else: frame = self.curframe self.shell.set_completer_frame(frame) result = self.shell.kernel._do_complete(code, cursor_pos) # Reset frame self.shell.set_completer_frame() # If there is no Pdb results to merge, return the result if not compfunc: return result ipy_matches = result['matches'] # Make sure both match lists start at the same place if cursor_start < result['cursor_start']: # Fill IPython matches missing_txt = code[cursor_start:result['cursor_start']] ipy_matches = [missing_txt + m for m in ipy_matches] elif result['cursor_start'] < cursor_start: # Fill Pdb matches missing_txt = code[result['cursor_start']:cursor_start] matches = [missing_txt + m for m in matches] cursor_start = result['cursor_start'] # Add Pdb-specific matches matches += [match for match in ipy_matches if match not in matches] return {'matches': matches, 'cursor_end': cursor_pos, 'cursor_start': cursor_start, 'metadata': {}, 'status': 'ok'} def _complete_exclamation(self, code, cursor_pos): """ Respond to a complete request if pdb_use_exclamation_mark. """ if cursor_pos is None: cursor_pos = len(code) # Get text to complete text = code[:cursor_pos].split(' ')[-1] # Choose Pdb function to complete, based on cmd.py origline = code line = origline.lstrip() if not line: # Nothing to complete return is_pdb_command = line[0] == '!' is_pdb_command_name = False stripped = len(origline) - len(line) begidx = cursor_pos - len(text) - stripped endidx = cursor_pos - stripped compfunc = None if is_pdb_command: line = line[1:] begidx -= 1 endidx -= 1 if begidx == -1: is_pdb_command_name = True text = text[1:] begidx += 1 compfunc = self.completenames else: cmd, args, _ = self.parseline(line) if cmd != '': try: # Function to complete Pdb command arguments compfunc = getattr(self, 'complete_' + cmd) except AttributeError: # This command doesn't exist, nothing to complete return else: # We don't know this command return if not is_pdb_command_name: # Remove eg. leading opening parenthesis def is_name_or_composed(text): if not text or text[0] == '.': return False # We want to keep value.subvalue return text.replace('.', '').isidentifier() while text and not is_name_or_composed(text): text = text[1:] begidx += 1 cursor_start = cursor_pos - len(text) matches = [] if is_pdb_command: matches = compfunc(text, line, begidx, endidx) return { 'matches': matches, 'cursor_end': cursor_pos, 'cursor_start': cursor_start, 'metadata': {}, 'status': 'ok' } # Make complete call with current frame if self.curframe: if self.curframe_locals: Frame = namedtuple("Frame", ["f_locals", "f_globals"]) frame = Frame(self.curframe_locals, self.curframe.f_globals) else: frame = self.curframe self.shell.set_completer_frame(frame) result = self.shell.kernel._do_complete(code, cursor_pos) # Reset frame self.shell.set_completer_frame() return result # --- Methods overriden by us for Spyder integration def postloop(self): # postloop() is called when the debugger’s input prompt exists. Reset # _previous_step so that get_pdb_state() actually notifies Spyder # about a changed frame the next the input prompt is entered again. self._previous_step = None def set_continue(self): """ Stop only at breakpoints or when finished. Reimplemented to avoid stepping out of debugging if there are no breakpoints. We could add more later. """ # Don't stop except at breakpoints or when finished self._set_stopinfo(self.botframe, None, -1) def do_debug(self, arg): """ Debug code Enter a recursive debugger that steps through the code argument (which is an arbitrary expression or statement to be executed in the current environment). """ with self.recursive_debugger() as debugger: self.message("Entering recursive debugger") try: global_ns = self.curframe.f_globals local_ns = self.curframe_locals return sys.call_tracing(debugger.run, (arg, global_ns, local_ns)) except Exception: exc_info = sys.exc_info()[:2] self.error( traceback.format_exception_only(*exc_info)[-1].strip()) finally: self.message("Leaving recursive debugger") @contextmanager def recursive_debugger(self): """Get a recursive debugger.""" # Save and restore tracing function trace_function = sys.gettrace() sys.settrace(None) # Create child debugger debugger = self.__class__( completekey=self.completekey, stdin=self.stdin, stdout=self.stdout) debugger.prompt = "(%s) " % self.prompt.strip() try: yield debugger finally: # Reset parent debugger sys.settrace(trace_function) self.lastcmd = debugger.lastcmd # Reset _previous_step so that get_pdb_state() notifies Spyder about # a changed debugger position. The reset is required because the # recursive debugger might change the position, but the parent # debugger (self) is not aware of this. self._previous_step = None def user_return(self, frame, return_value): """This function is called when a return trap is set here.""" # This is useful when debugging in an active interpreter (otherwise, # the debugger will stop before reaching the target file) if self._wait_for_mainpyfile: if (self.mainpyfile != self.canonic(frame.f_code.co_filename) or frame.f_lineno <= 0): return self._wait_for_mainpyfile = False super(SpyderPdb, self).user_return(frame, return_value) def _cmdloop(self): """Modifies the error text.""" self.interrupting = False while True: try: # keyboard interrupts allow for an easy way to cancel # the current command, so allow them during interactive input self.allow_kbdint = True self.cmdloop() self.allow_kbdint = False break except KeyboardInterrupt: print("--KeyboardInterrupt--\n" "For copying text while debugging, use Ctrl+Shift+C", file=self.stdout) @lru_cache def canonic(self, filename): """ Return canonical form of filename. In some case two path can point to the same file. For this reason os.path.samefile uses os.stat. Here we normalise the path with os.stat so a single path is returned for the same file. see: https://docs.python.org/3/library/os.path.html#os.path.samefile note: os.stat can be slow on windows so call it once per file. """ if filename == "<" + filename[1:-1] + ">": return filename filename = super().canonic(filename) if filename in self._canonic_filename_to_inode: inode = self._canonic_filename_to_inode[filename] else: try: stat = os.stat(filename) except OSError: self._canonic_filename_to_inode[filename] = None return filename inode = (stat.st_dev, stat.st_ino) if stat.st_ino == 0: inode = None self._canonic_filename_to_inode[filename] = inode if inode is not None and inode not in self._canonic_inode_to_filename: # First time this inode is seen self._canonic_inode_to_filename[inode] = filename if inode is None: return filename return self._canonic_inode_to_filename[inode] def do_exitdb(self, arg): """Exit the debugger""" self._set_stopinfo(self.botframe, None, -1) sys.settrace(None) frame = sys._getframe().f_back while frame and frame is not self.botframe: del frame.f_trace frame = frame.f_back return 1 def cmdloop(self, intro=None): """ Repeatedly issue a prompt, accept input, parse an initial prefix off the received input, and dispatch to action methods, passing them the remainder of the line as argument. """ self.preloop() if intro is not None: self.intro = intro if self.intro: self.stdout.write(str(self.intro)+"\n") stop = None while not stop: if self.cmdqueue: line = self.cmdqueue.pop(0) else: try: line = self.cmd_input(self.prompt) except EOFError: line = 'EOF' line = self.precmd(line) stop = self.onecmd(line) stop = self.postcmd(stop, line) self.postloop() def cmd_input(self, prompt=''): """ Get input from frontend. Blocks until return """ kernel = self.shell.kernel # Only works if the comm is open if not kernel.frontend_comm.is_open(): return input(prompt) # Flush output before making the request. sys.stderr.flush() sys.stdout.flush() sys.__stderr__.flush() sys.__stdout__.flush() # Send the input request. self._cmd_input_line = None kernel.frontend_call(display_error=True).pdb_input( prompt, state=self.get_pdb_state()) # Allow GUI event loop to update is_main_thread = ( threading.current_thread() is threading.main_thread()) # Get input by running eventloop if is_main_thread and kernel.eventloop: while self._cmd_input_line is None: eventloop = kernel.eventloop # Check if the current backend is Tk on Windows # to let GUI update. # See spyder-ide/spyder#17523 if (eventloop and hasattr(kernel, "app_wrapper") and os.name == "nt"): kernel.app_wrapper.app.update() elif eventloop: eventloop(kernel) else: break # Get input by blocking if self._cmd_input_line is None: kernel.frontend_comm.wait_until( lambda: self._cmd_input_line is not None) return self._cmd_input_line def precmd(self, line): """ Hook method executed just before the command line is interpreted, but after the input prompt is generated and issued. Here we switch ! and non ! """ if not self.pdb_use_exclamation_mark: return line if not line: return line if line[0] == '!': line = line[1:] else: line = '!' + line return line def postcmd(self, stop, line): """Hook method executed just after a command dispatch is finished.""" # Flush in case the command produced output on underlying outputs sys.__stderr__.flush() sys.__stdout__.flush() return stop # --- Methods defined by us for Spyder integration def set_spyder_breakpoints(self, breakpoints): """Set Spyder breakpoints.""" self.clear_all_breaks() # -----Really deleting all breakpoints: for bp in bdb.Breakpoint.bpbynumber: if bp: bp.deleteMe() bdb.Breakpoint.next = 1 bdb.Breakpoint.bplist = {} bdb.Breakpoint.bpbynumber = [None] # ----- for fname, data in list(breakpoints.items()): for linenumber, condition in data: try: self.set_break(self.canonic(fname), linenumber, cond=condition) except ValueError: # Fixes spyder/issues/15546 # The file is not readable pass breakpoints = property(fset=set_spyder_breakpoints) def get_pdb_state(self): """ Send debugger state (frame position) to the frontend. The state is only sent if it has changed since the last update. """ state = self.shell.kernel.get_state() frame = self.curframe if frame is None: self._previous_step = None return state if self._request_where: self._request_where = False state["do_where"] = True # Get filename and line number of the current frame fname = self.canonic(frame.f_code.co_filename) if fname == self.mainpyfile and self.remote_filename is not None: fname = self.remote_filename lineno = frame.f_lineno if self._previous_step == (fname, lineno): # Do not update state if not needed return state # Set step of the current frame (if any) step = {} self._previous_step = None if isinstance(fname, str) and isinstance(lineno, int): step = dict(fname=fname, lineno=lineno) self._previous_step = (fname, lineno) state['step'] = step if self.pdb_publish_stack: # Publish Pdb stack so we can update the Debugger plugin on Spyder pdb_stack = stacksummary_to_json( traceback.StackSummary.extract(self.stack) ) pdb_index = self.curindex skip_hidden = getattr(self, 'skip_hidden', False) if skip_hidden: # Filter out the hidden frames hidden = self.hidden_frames(self.stack) pdb_stack = [f for f, h in zip(pdb_stack, hidden) if not h] # Adjust the index pdb_index -= sum([bool(i) for i in hidden[:pdb_index]]) state['stack'] = (pdb_stack, pdb_index) return state def run(self, cmd, globals=None, locals=None): """Debug a statement executed via the exec() function. globals defaults to __main__.dict; locals defaults to globals. """ with DebugWrapper(self): super(SpyderPdb, self).run(cmd, globals, locals) def runeval(self, expr, globals=None, locals=None): """Debug an expression executed via the eval() function. globals defaults to __main__.dict; locals defaults to globals. """ with DebugWrapper(self): super(SpyderPdb, self).runeval(expr, globals, locals) def runcall(self, *args, **kwds): """Debug a single function call. Return the result of the function call. """ with DebugWrapper(self): super(SpyderPdb, self).runcall(*args, **kwds) def set_remote_filename(self, filename): """Set remote filename to signal Spyder on mainpyfile.""" self.remote_filename = filename self.mainpyfile = self.canonic(filename) self._wait_for_mainpyfile = True