May 6, 2024 · Oct 20, 2023 · Oct 20, 2023 · Oct 20, 2023 · May 4, 2024 · May 5, 2024
diff --git a/Lib/pdb.py b/Lib/pdb.py
 import code
 import glob
 import token
 import types
 import codeop
 import pprint
 import signal
 import inspect
 import textwrap
 import tokenize
 import traceback
 import linecache
            self.completenames = completenames
        return

    def _exec_in_closure(self, source, globals, locals):
        """ Run source code in closure so code object created within source
            can find variables in locals correctly

            returns True if the source is executed, False otherwise
        """

        # Determine if the source should be executed in closure. Only when the
        # source compiled to multiple code objects, we should use this feature.
        # Otherwise, we can just raise an exception and normal exec will be used.

        code = compile(source, "<string>", "exec")
        if not any(isinstance(const, CodeType) for const in code.co_consts):
            return False

        # locals could be a proxy which does not support pop
        # copy it first to avoid modifying the original locals
        locals_copy = dict(locals)

        locals_copy["__pdb_eval__"] = {
            "result": None,
            "write_back": {}
        }

        # If the source is an expression, we need to print its value
        try:
            compile(source, "<string>", "eval")
        except SyntaxError:
            pass
        else:
            source = "__pdb_eval__['result'] = " + source

        # Add write-back to update the locals
        source = ("try:\n" +
                  textwrap.indent(source, "  ") + "\n" +
                  "finally:\n" +
                  "  __pdb_eval__['write_back'] = locals()")

        # Build a closure source code with freevars from locals like:
        # def __pdb_outer():
        #   var = None
        #   def __pdb_scope():  # This is the code object we want to execute
        #     nonlocal var
        #     <source>
        #   return __pdb_scope.__code__
        source_with_closure = ("def __pdb_outer():\n" +
                               "\n".join(f"  {var} = None" for var in locals_copy) + "\n" +
                               "  def __pdb_scope():\n" +
                               "\n".join(f"    nonlocal {var}" for var in locals_copy) + "\n" +
                               textwrap.indent(source, "    ") + "\n" +
                               "  return __pdb_scope.__code__"
                               )

        # Get the code object of __pdb_scope()
        # The exec fills locals_copy with the __pdb_outer() function and we can call
        # that to get the code object of __pdb_scope()
        ns = {}
        try:
            exec(source_with_closure, {}, ns)
        except Exception:
            return False
        code = ns["__pdb_outer"]()

        cells = tuple(types.CellType(locals_copy.get(var)) for var in code.co_freevars)

        try:
            exec(code, globals, locals_copy, closure=cells)
        except Exception:
            return False

        # get the data we need from the statement
        pdb_eval = locals_copy["__pdb_eval__"]

        # __pdb_eval__ should not be updated back to locals
        pdb_eval["write_back"].pop("__pdb_eval__")

        # Write all local variables back to locals
        locals.update(pdb_eval["write_back"])
        eval_result = pdb_eval["result"]
        if eval_result is not None:
            print(repr(eval_result))

        return True

    def default(self, line):
        if line[:1] == '!': line = line[1:].strip()
        locals = self.curframe_locals
        globals = self.curframe.f_globals
        try:
            buffer = line
            if (code := codeop.compile_command(line + '\n', '<stdin>', 'single')) is None:
                # Multi-line mode
                with self._disable_command_completion():
                sys.stdin = self.stdin
                sys.stdout = self.stdout
                sys.displayhook = self.displayhook
                exec(code, globals, locals)
                if not self._exec_in_closure(buffer, globals, locals):
                    exec(code, globals, locals)
            finally:
                sys.stdout = save_stdout
                sys.stdin = save_stdin
diff --git a/Lib/test/test_pdb.py b/Lib/test/test_pdb.py
    (Pdb) c
    """

 def test_pdb_closure():
    """Test for all expressions/statements that involve closure

    >>> k = 0
    >>> g = 1
    >>> def test_function():
    ...     x = 2
    ...     g = 3
    ...     import pdb; pdb.Pdb(nosigint=True, readrc=False).set_trace()

    >>> with PdbTestInput([  # doctest: +NORMALIZE_WHITESPACE
    ...     'k',
    ...     'g',
    ...     'y = y',
    ...     'global g; g',
    ...     'global g; (lambda: g)()',
    ...     '(lambda: x)()',
    ...     '(lambda: g)()',
    ...     'lst = [n for n in range(10) if (n % x) == 0]',
    ...     'lst',
    ...     'sum(n for n in lst if n > x)',
    ...     'x = 1; raise Exception()',
    ...     'x',
    ...     'def f():',
    ...     '  return x',
    ...     '',
    ...     'f()',
    ...     'c'
    ... ]):
    ...     test_function()
    > <doctest test.test_pdb.test_pdb_closure[2]>(4)test_function()
    -> import pdb; pdb.Pdb(nosigint=True, readrc=False).set_trace()
    (Pdb) k
    0
    (Pdb) g
    3
    (Pdb) y = y
    *** NameError: name 'y' is not defined
    (Pdb) global g; g
    1
    (Pdb) global g; (lambda: g)()
    1
    (Pdb) (lambda: x)()
    2
    (Pdb) (lambda: g)()
    3
    (Pdb) lst = [n for n in range(10) if (n % x) == 0]
    (Pdb) lst
    [0, 2, 4, 6, 8]
    (Pdb) sum(n for n in lst if n > x)
    18
    (Pdb) x = 1; raise Exception()
    *** Exception
    (Pdb) x
    1
    (Pdb) def f():
    ...     return x
    ...
    (Pdb) f()
    1
    (Pdb) c
    """

 def test_pdb_show_attribute_and_item():
    """Test formultiline statement
    """Test forexpressions with command prefix

    >>> def test_function():
    ...     n = lambda x: x
diff --git a/Misc/NEWS.d/next/Library/2023-10-20-03-50-17.gh-issue-83151.bcsD40.rst b/Misc/NEWS.d/next/Library/2023-10-20-03-50-17.gh-issue-83151.bcsD40.rst
 Enabled arbitrary statements and evaluations in :mod:`pdb` shell to access the
 local variables of the current frame, which made it possible for multi-scope
 code like generators or nested function to work.
Original file line number	Diff line number	Diff line change
Expand Up		@@ -77,10 +77,12 @@
		import code
		import glob
		import token
		import types
		import codeop
		import pprint
		import signal
		import inspect
		import textwrap
		import tokenize
		import traceback
		import linecache
Expand DownExpand Up		@@ -624,11 +626,96 @@ def _disable_command_completion(self):
		self.completenames = completenames
		return

		def _exec_in_closure(self, source, globals, locals):
		""" Run source code in closure so code object created within source
		can find variables in locals correctly

		returns True if the source is executed, False otherwise
		"""

		# Determine if the source should be executed in closure. Only when the
		# source compiled to multiple code objects, we should use this feature.
		# Otherwise, we can just raise an exception and normal exec will be used.

		code = compile(source, "<string>", "exec")
		if not any(isinstance(const, CodeType) for const in code.co_consts):
		return False

		# locals could be a proxy which does not support pop
		# copy it first to avoid modifying the original locals
		locals_copy = dict(locals)

		locals_copy["__pdb_eval__"] = {
		"result": None,
		"write_back": {}
		}
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		# If the source is an expression, we need to print its value
		try:
		compile(source, "<string>", "eval")
		except SyntaxError:
		pass
		else:
		source = "__pdb_eval__['result'] = " + source

		# Add write-back to update the locals
		source = ("try:\n" +
		textwrap.indent(source, " ") + "\n" +
		"finally:\n" +
		" __pdb_eval__['write_back'] = locals()")

		# Build a closure source code with freevars from locals like:
		# def __pdb_outer():
		# var = None
		# def __pdb_scope(): # This is the code object we want to execute
		# nonlocal var
		# <source>
		# return __pdb_scope.__code__
		source_with_closure = ("def __pdb_outer():\n" +
		"\n".join(f" {var} = None" for var in locals_copy) + "\n" +
		" def __pdb_scope():\n" +
		"\n".join(f" nonlocal {var}" for var in locals_copy) + "\n" +
		textwrap.indent(source, " ") + "\n" +
		" return __pdb_scope.__code__"
		)

		# Get the code object of __pdb_scope()
		# The exec fills locals_copy with the __pdb_outer() function and we can call
		# that to get the code object of __pdb_scope()
		ns = {}
		try:
		exec(source_with_closure, {}, ns)
		except Exception:
		return False
		code = ns["__pdb_outer"]()

		cells = tuple(types.CellType(locals_copy.get(var)) for var in code.co_freevars)

		try:
		exec(code, globals, locals_copy, closure=cells)
		except Exception:
		return False
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		# get the data we need from the statement
		pdb_eval = locals_copy["__pdb_eval__"]

		# __pdb_eval__ should not be updated back to locals
		pdb_eval["write_back"].pop("__pdb_eval__")
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		# Write all local variables back to locals
		locals.update(pdb_eval["write_back"])
		eval_result = pdb_eval["result"]
		if eval_result is not None:
		print(repr(eval_result))

		return True

		def default(self, line):
		if line[:1] == '!': line = line[1:].strip()
		locals = self.curframe_locals
		globals = self.curframe.f_globals
		try:
		buffer = line
		if (code := codeop.compile_command(line + '\n', '<stdin>', 'single')) is None:
		# Multi-line mode
		with self._disable_command_completion():
Expand DownExpand Up		@@ -661,7 +748,8 @@ def default(self, line):
		sys.stdin = self.stdin
		sys.stdout = self.stdout
		sys.displayhook = self.displayhook
		exec(code, globals, locals)
		if not self._exec_in_closure(buffer, globals, locals):
		exec(code, globals, locals)
		finally:
		sys.stdout = save_stdout
		sys.stdin = save_stdin
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -2224,8 +2224,71 @@ def test_pdb_multiline_statement():
		(Pdb) c
		"""

		def test_pdb_closure():
		"""Test for all expressions/statements that involve closure

		>>> k = 0
		>>> g = 1
		>>> def test_function():
		... x = 2
		... g = 3
		... import pdb; pdb.Pdb(nosigint=True, readrc=False).set_trace()

		>>> with PdbTestInput([ # doctest: +NORMALIZE_WHITESPACE
		... 'k',
		... 'g',
		... 'y = y',
		... 'global g; g',
		... 'global g; (lambda: g)()',
		... '(lambda: x)()',
		... '(lambda: g)()',
		... 'lst = [n for n in range(10) if (n % x) == 0]',
		... 'lst',
		... 'sum(n for n in lst if n > x)',
		... 'x = 1; raise Exception()',
		... 'x',
		... 'def f():',
		... ' return x',
		... '',
		... 'f()',
		... 'c'
		... ]):
		... test_function()
		> <doctest test.test_pdb.test_pdb_closure[2]>(4)test_function()
		-> import pdb; pdb.Pdb(nosigint=True, readrc=False).set_trace()
		(Pdb) k
		0
		(Pdb) g
		3
		(Pdb) y = y
		*** NameError: name 'y' is not defined
		(Pdb) global g; g
		1
		(Pdb) global g; (lambda: g)()
		1
		(Pdb) (lambda: x)()
		2
		(Pdb) (lambda: g)()
		3
		(Pdb) lst = [n for n in range(10) if (n % x) == 0]
		(Pdb) lst
		[0, 2, 4, 6, 8]
		(Pdb) sum(n for n in lst if n > x)
		18
		(Pdb) x = 1; raise Exception()
		*** Exception
		(Pdb) x
		1
		(Pdb) def f():
		... return x
		...
		(Pdb) f()
		1
		(Pdb) c
		"""

		def test_pdb_show_attribute_and_item():
		"""Test formultiline statement
		"""Test forexpressions with command prefix

		>>> def test_function():
		... n = lambda x: x
Expand Down
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,3 @@
		Enabled arbitrary statements and evaluations in :mod:`pdb` shell to access the
		local variables of the current frame, which made it possible for multi-scope
		code like generators or nested function to work.