This is Richie Hindle's patch
[ 643835 ] Set Next Statement for Python debuggers with a few tweaks by me: adding an unsigned or two, mentioning that not all jumps are allowed in the doc for pdb, adding a NEWS item and a note to whatsnew, and AuCTeX doing something cosmetic to libpdb.tex.
This commit is contained in:
Michael W. Hudson
parent
f680cc460c
commit
cfd3884882
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@ -255,6 +255,16 @@ Continue execution until the current function returns.
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Continue execution, only stop when a breakpoint is encountered.
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\item[j(ump) \var{lineno}]
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Set the next line that will be executed. Only available in the
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bottom-most frame. This lets you jump back and execute code
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again, or jump forward to skip code that you don't want to run.
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It should be noted that not all jumps are allowed -- for instance it
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it not possible to jump into the middle of a for loop or out of a
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finally clause.
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\item[l(ist) \optional{\var{first\optional{, last}}}]
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List source code for the current file. Without arguments, list 11
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@ -303,7 +313,7 @@ alias pi for k in %1.__dict__.keys(): print "%1.",k,"=",%1.__dict__[k]
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#Print instance variables in self
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alias ps pi self
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\end{verbatim}
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\item[unalias \var{name}]
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Deletes the specified alias.
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@ -812,8 +812,7 @@ frame; \member{f_locals} is the dictionary used to look up local
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variables; \member{f_globals} is used for global variables;
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\member{f_builtins} is used for built-in (intrinsic) names;
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\member{f_restricted} is a flag indicating whether the function is
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executing in restricted execution mode;
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\member{f_lineno} gives the line number and \member{f_lasti} gives the
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executing in restricted execution mode; \member{f_lasti} gives the
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precise instruction (this is an index into the bytecode string of
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the code object).
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\withsubitem{(frame attribute)}{
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@ -821,7 +820,6 @@ the code object).
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\ttindex{f_code}
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\ttindex{f_globals}
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\ttindex{f_locals}
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\ttindex{f_lineno}
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\ttindex{f_lasti}
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\ttindex{f_builtins}
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\ttindex{f_restricted}}
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@ -830,12 +828,16 @@ Special writable attributes: \member{f_trace}, if not \code{None}, is a
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function called at the start of each source code line (this is used by
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the debugger); \member{f_exc_type}, \member{f_exc_value},
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\member{f_exc_traceback} represent the most recent exception caught in
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this frame.
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this frame; \member{f_lineno} is the current line number of the frame
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--- writing to this from within a trace function jumps to the given line
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(only for the bottom-most frame). A debugger can implement a Jump
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command (aka Set Next Statement) by writing to f_lineno.
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\withsubitem{(frame attribute)}{
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\ttindex{f_trace}
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\ttindex{f_exc_type}
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\ttindex{f_exc_value}
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\ttindex{f_exc_traceback}}
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\ttindex{f_exc_traceback}
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\ttindex{f_lineno}}
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\item[Traceback objects] \label{traceback}
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Traceback objects represent a stack trace of an exception. A
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@ -12,6 +12,8 @@
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% MacOS framework-related changes (section of its own, probably)
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% the new set-next-statement functionality of pdb (SF #643835)
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%\section{Introduction \label{intro}}
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{\large This article is a draft, and is currently up to date for some
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@ -1201,13 +1203,13 @@ For example:
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\begin{verbatim}
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>>> days = ['Mo', 'Tu', 'We', 'Th', 'Fr', 'St', 'Sn']
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>>> random.sample(days, 3) # Choose 3 elements
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>>> random.sample(days, 3) # Choose 3 elements
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['St', 'Sn', 'Th']
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>>> random.sample(days, 7) # Choose 7 elements
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>>> random.sample(days, 7) # Choose 7 elements
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['Tu', 'Th', 'Mo', 'We', 'St', 'Fr', 'Sn']
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>>> random.sample(days, 7) # Choose 7 again
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>>> random.sample(days, 7) # Choose 7 again
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['We', 'Mo', 'Sn', 'Fr', 'Tu', 'St', 'Th']
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>>> random.sample(days, 8) # Can't choose eight
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>>> random.sample(days, 8) # Can't choose eight
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Traceback (most recent call last):
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File "<stdin>", line 1, in ?
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File "random.py", line 414, in sample
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26
Lib/pdb.py
26
Lib/pdb.py
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@ -506,6 +506,25 @@ class Pdb(bdb.Bdb, cmd.Cmd):
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return 1
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do_c = do_cont = do_continue
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def do_jump(self, arg):
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if self.curindex + 1 != len(self.stack):
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print "*** You can only jump within the bottom frame"
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return
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try:
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arg = int(arg)
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except ValueError:
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print "*** The 'jump' command requires a line number."
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else:
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try:
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# Do the jump, fix up our copy of the stack, and display the
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# new position
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self.curframe.f_lineno = arg
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self.stack[self.curindex] = self.stack[self.curindex][0], arg
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self.print_stack_entry(self.stack[self.curindex])
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except ValueError, e:
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print '*** Jump failed:', e
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do_j = do_jump
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def do_quit(self, arg):
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self.set_quit()
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return 1
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@ -805,6 +824,13 @@ Continue execution until the current function returns."""
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print """c(ont(inue))
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Continue execution, only stop when a breakpoint is encountered."""
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def help_jump(self):
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self.help_j()
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def help_j(self):
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print """j(ump) lineno
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Set the next line that will be executed."""
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def help_list(self):
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self.help_l()
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@ -221,9 +221,298 @@ class RaisingTraceFuncTestCase(unittest.TestCase):
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def test_exception(self):
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self.run_test_for_event('exception')
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# 'Jump' tests: assigning to frame.f_lineno within a trace function
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# moves the execution position - it's how debuggers implement a Jump
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# command (aka. "Set next statement").
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class JumpTracer:
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"""Defines a trace function that jumps from one place to another,
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with the source and destination lines of the jump being defined by
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the 'jump' property of the function under test."""
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def __init__(self, function):
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self.function = function
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self.jumpFrom = function.jump[0]
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self.jumpTo = function.jump[1]
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self.done = False
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def trace(self, frame, event, arg):
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if not self.done and frame.f_code == self.function.func_code:
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firstLine = frame.f_code.co_firstlineno
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if frame.f_lineno == firstLine + self.jumpFrom:
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# Cope with non-integer self.jumpTo (because of
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# no_jump_to_non_integers below).
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try:
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frame.f_lineno = firstLine + self.jumpTo
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except TypeError:
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frame.f_lineno = self.jumpTo
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self.done = True
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return self.trace
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# The first set of 'jump' tests are for things that are allowed:
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def jump_simple_forwards(output):
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output.append(1)
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output.append(2)
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output.append(3)
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jump_simple_forwards.jump = (1, 3)
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jump_simple_forwards.output = [3]
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def jump_simple_backwards(output):
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output.append(1)
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output.append(2)
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jump_simple_backwards.jump = (2, 1)
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jump_simple_backwards.output = [1, 1, 2]
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def jump_out_of_block_forwards(output):
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for i in 1, 2:
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output.append(2)
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for j in [3]: # Also tests jumping over a block
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output.append(4)
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output.append(5)
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jump_out_of_block_forwards.jump = (3, 5)
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jump_out_of_block_forwards.output = [2, 5]
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def jump_out_of_block_backwards(output):
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output.append(1)
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for i in [1]:
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output.append(3)
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for j in [2]: # Also tests jumping over a block
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output.append(5)
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output.append(6)
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output.append(7)
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jump_out_of_block_backwards.jump = (6, 1)
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jump_out_of_block_backwards.output = [1, 3, 5, 1, 3, 5, 6, 7]
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def jump_to_codeless_line(output):
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output.append(1)
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# Jumping to this line should skip to the next one.
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output.append(3)
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jump_to_codeless_line.jump = (1, 2)
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jump_to_codeless_line.output = [3]
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def jump_to_same_line(output):
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output.append(1)
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output.append(2)
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output.append(3)
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jump_to_same_line.jump = (2, 2)
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jump_to_same_line.output = [1, 2, 3]
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# Tests jumping within a finally block, and over one.
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def jump_in_nested_finally(output):
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try:
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output.append(2)
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finally:
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output.append(4)
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try:
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output.append(6)
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finally:
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output.append(8)
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output.append(9)
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jump_in_nested_finally.jump = (4, 9)
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jump_in_nested_finally.output = [2, 9]
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# The second set of 'jump' tests are for things that are not allowed:
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def no_jump_too_far_forwards(output):
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try:
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output.append(2)
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output.append(3)
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except ValueError, e:
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output.append('after' in str(e))
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no_jump_too_far_forwards.jump = (3, 6)
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no_jump_too_far_forwards.output = [2, True]
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def no_jump_too_far_backwards(output):
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try:
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output.append(2)
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output.append(3)
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except ValueError, e:
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output.append('before' in str(e))
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no_jump_too_far_backwards.jump = (3, -1)
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no_jump_too_far_backwards.output = [2, True]
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# Test each kind of 'except' line.
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def no_jump_to_except_1(output):
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try:
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output.append(2)
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except:
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e = sys.exc_info()[1]
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output.append('except' in str(e))
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no_jump_to_except_1.jump = (2, 3)
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no_jump_to_except_1.output = [True]
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def no_jump_to_except_2(output):
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try:
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output.append(2)
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except ValueError:
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e = sys.exc_info()[1]
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output.append('except' in str(e))
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no_jump_to_except_2.jump = (2, 3)
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no_jump_to_except_2.output = [True]
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def no_jump_to_except_3(output):
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try:
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output.append(2)
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except ValueError, e:
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output.append('except' in str(e))
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no_jump_to_except_3.jump = (2, 3)
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no_jump_to_except_3.output = [True]
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def no_jump_to_except_4(output):
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try:
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output.append(2)
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except (ValueError, RuntimeError), e:
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output.append('except' in str(e))
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no_jump_to_except_4.jump = (2, 3)
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no_jump_to_except_4.output = [True]
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def no_jump_forwards_into_block(output):
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try:
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output.append(2)
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for i in 1, 2:
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output.append(4)
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except ValueError, e:
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output.append('into' in str(e))
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no_jump_forwards_into_block.jump = (2, 4)
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no_jump_forwards_into_block.output = [True]
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def no_jump_backwards_into_block(output):
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try:
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for i in 1, 2:
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output.append(3)
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output.append(4)
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except ValueError, e:
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output.append('into' in str(e))
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no_jump_backwards_into_block.jump = (4, 3)
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no_jump_backwards_into_block.output = [3, 3, True]
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def no_jump_into_finally_block(output):
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try:
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try:
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output.append(3)
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x = 1
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finally:
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output.append(6)
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except ValueError, e:
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output.append('finally' in str(e))
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no_jump_into_finally_block.jump = (4, 6)
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no_jump_into_finally_block.output = [3, 6, True] # The 'finally' still runs
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def no_jump_out_of_finally_block(output):
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try:
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try:
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output.append(3)
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finally:
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output.append(5)
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output.append(6)
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except ValueError, e:
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output.append('finally' in str(e))
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no_jump_out_of_finally_block.jump = (5, 1)
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no_jump_out_of_finally_block.output = [3, True]
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# This verifies the line-numbers-must-be-integers rule.
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def no_jump_to_non_integers(output):
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try:
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output.append(2)
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except ValueError, e:
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output.append('integer' in str(e))
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no_jump_to_non_integers.jump = (2, "Spam")
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no_jump_to_non_integers.output = [True]
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# This verifies that you can't set f_lineno via _getframe or similar
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# trickery.
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def no_jump_without_trace_function():
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try:
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previous_frame = sys._getframe().f_back
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previous_frame.f_lineno = previous_frame.f_lineno
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except ValueError, e:
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# This is the exception we wanted; make sure the error message
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# talks about trace functions.
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if 'trace' not in str(e):
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raise
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else:
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# Something's wrong - the expected exception wasn't raised.
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raise RuntimeError, "Trace-function-less jump failed to fail"
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class JumpTestCase(unittest.TestCase):
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def compare_jump_output(self, expected, received):
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if received != expected:
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self.fail( "Outputs don't match:\n" +
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"Expected: " + repr(expected) + "\n" +
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"Received: " + repr(received))
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def run_test(self, func):
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tracer = JumpTracer(func)
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sys.settrace(tracer.trace)
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output = []
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func(output)
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sys.settrace(None)
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self.compare_jump_output(func.output, output)
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def test_01_jump_simple_forwards(self):
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self.run_test(jump_simple_forwards)
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def test_02_jump_simple_backwards(self):
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self.run_test(jump_simple_backwards)
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def test_03_jump_out_of_block_forwards(self):
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self.run_test(jump_out_of_block_forwards)
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def test_04_jump_out_of_block_backwards(self):
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self.run_test(jump_out_of_block_backwards)
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def test_05_jump_to_codeless_line(self):
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self.run_test(jump_to_codeless_line)
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def test_06_jump_to_same_line(self):
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self.run_test(jump_to_same_line)
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def test_07_jump_in_nested_finally(self):
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self.run_test(jump_in_nested_finally)
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def test_08_no_jump_too_far_forwards(self):
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self.run_test(no_jump_too_far_forwards)
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def test_09_no_jump_too_far_backwards(self):
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self.run_test(no_jump_too_far_backwards)
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def test_10_no_jump_to_except_1(self):
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self.run_test(no_jump_to_except_1)
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def test_11_no_jump_to_except_2(self):
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self.run_test(no_jump_to_except_2)
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def test_12_no_jump_to_except_3(self):
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self.run_test(no_jump_to_except_3)
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def test_13_no_jump_to_except_4(self):
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self.run_test(no_jump_to_except_4)
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def test_14_no_jump_forwards_into_block(self):
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self.run_test(no_jump_forwards_into_block)
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def test_15_no_jump_backwards_into_block(self):
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self.run_test(no_jump_backwards_into_block)
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def test_16_no_jump_into_finally_block(self):
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self.run_test(no_jump_into_finally_block)
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def test_17_no_jump_out_of_finally_block(self):
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self.run_test(no_jump_out_of_finally_block)
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def test_18_no_jump_to_non_integers(self):
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self.run_test(no_jump_to_non_integers)
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def test_19_no_jump_without_trace_function(self):
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no_jump_without_trace_function()
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def test_main():
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test_support.run_unittest(TraceTestCase)
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test_support.run_unittest(RaisingTraceFuncTestCase)
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test_support.run_unittest(JumpTestCase)
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if __name__ == "__main__":
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test_main()
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11
Misc/NEWS
11
Misc/NEWS
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@ -84,6 +84,10 @@ Type/class unification and new-style classes
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Core and builtins
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-----------------
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- A frame object's f_lineno attribute can now be written to from a
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trace function to change which line will execute next. A command to
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exploit this from pdb has been added. [SF patch #643835]
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- The _codecs support module for codecs.py was turned into a builtin
|
||||
module to assure that at least the builtin codecs are available
|
||||
to the Python parser for source code decoding according to PEP 263.
|
||||
|
|
@ -118,8 +122,8 @@ Core and builtins
|
|||
|
||||
- SET_LINENO is gone. co_lnotab is now consulted to determine when to
|
||||
call the trace function. C code that accessed f_lineno should call
|
||||
PyCode_Addr2Line instead (f_lineno is still there, but not kept up
|
||||
to date).
|
||||
PyCode_Addr2Line instead (f_lineno is still there, but only kept up
|
||||
to date when there is a trace function set).
|
||||
|
||||
- There's a new warning category, FutureWarning. This is used to warn
|
||||
about a number of situations where the value or sign of an integer
|
||||
|
|
@ -439,6 +443,9 @@ Extension modules
|
|||
Library
|
||||
-------
|
||||
|
||||
- pdb has a new 'j(ump)' command to select the next line to be
|
||||
executed.
|
||||
|
||||
- The distutils created windows installers now can run a
|
||||
postinstallation script.
|
||||
|
||||
|
|
|
|||
|
|
@ -8,6 +8,9 @@
|
|||
#include "opcode.h"
|
||||
#include "structmember.h"
|
||||
|
||||
#define MIN(a, b) ((a) < (b) ? (a) : (b))
|
||||
#define MAX(a, b) ((a) > (b) ? (a) : (b))
|
||||
|
||||
#define OFF(x) offsetof(PyFrameObject, x)
|
||||
|
||||
static PyMemberDef frame_memberlist[] = {
|
||||
|
|
@ -44,6 +47,260 @@ frame_getlineno(PyFrameObject *f, void *closure)
|
|||
return PyInt_FromLong(lineno);
|
||||
}
|
||||
|
||||
/* Setter for f_lineno - you can set f_lineno from within a trace function in
|
||||
* order to jump to a given line of code, subject to some restrictions. Most
|
||||
* lines are OK to jump to because they don't make any assumptions about the
|
||||
* state of the stack (obvious because you could remove the line and the code
|
||||
* would still work without any stack errors), but there are some constructs
|
||||
* that limit jumping:
|
||||
*
|
||||
* o Lines with an 'except' statement on them can't be jumped to, because
|
||||
* they expect an exception to be on the top of the stack.
|
||||
* o Lines that live in a 'finally' block can't be jumped from or to, since
|
||||
* the END_FINALLY expects to clean up the stack after the 'try' block.
|
||||
* o 'try'/'for'/'while' blocks can't be jumped into because the blockstack
|
||||
* needs to be set up before their code runs, and for 'for' loops the
|
||||
* iterator needs to be on the stack.
|
||||
*/
|
||||
static int
|
||||
frame_setlineno(PyFrameObject *f, PyObject* p_new_lineno)
|
||||
{
|
||||
int new_lineno = 0; /* The new value of f_lineno */
|
||||
int new_lasti = 0; /* The new value of f_lasti */
|
||||
int new_iblock = 0; /* The new value of f_iblock */
|
||||
char *code = NULL; /* The bytecode for the frame... */
|
||||
int code_len = 0; /* ...and its length */
|
||||
char *lnotab = NULL; /* Iterating over co_lnotab */
|
||||
int lnotab_len = 0; /* (ditto) */
|
||||
int offset = 0; /* (ditto) */
|
||||
int line = 0; /* (ditto) */
|
||||
int addr = 0; /* (ditto) */
|
||||
int min_addr = 0; /* Scanning the SETUPs and POPs */
|
||||
int max_addr = 0; /* (ditto) */
|
||||
int delta_iblock = 0; /* (ditto) */
|
||||
int min_delta_iblock = 0; /* (ditto) */
|
||||
int min_iblock = 0; /* (ditto) */
|
||||
int f_lasti_setup_addr = 0; /* Policing no-jump-into-finally */
|
||||
int new_lasti_setup_addr = 0; /* (ditto) */
|
||||
int blockstack[CO_MAXBLOCKS]; /* Walking the 'finally' blocks */
|
||||
int in_finally[CO_MAXBLOCKS]; /* (ditto) */
|
||||
int blockstack_top = 0; /* (ditto) */
|
||||
int setup_op = 0; /* (ditto) */
|
||||
|
||||
/* f_lineno must be an integer. */
|
||||
if (!PyInt_Check(p_new_lineno)) {
|
||||
PyErr_SetString(PyExc_ValueError,
|
||||
"lineno must be an integer");
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* You can only do this from within a trace function, not via
|
||||
* _getframe or similar hackery. */
|
||||
if (!f->f_trace)
|
||||
{
|
||||
PyErr_Format(PyExc_ValueError,
|
||||
"f_lineno can only be set by a trace function");
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* Fail if the line comes before the start of the code block. */
|
||||
new_lineno = (int) PyInt_AsLong(p_new_lineno);
|
||||
if (new_lineno < f->f_code->co_firstlineno) {
|
||||
PyErr_Format(PyExc_ValueError,
|
||||
"line %d comes before the current code block",
|
||||
new_lineno);
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* Find the bytecode offset for the start of the given line, or the
|
||||
* first code-owning line after it. */
|
||||
PyString_AsStringAndSize(f->f_code->co_lnotab, &lnotab, &lnotab_len);
|
||||
addr = 0;
|
||||
line = f->f_code->co_firstlineno;
|
||||
new_lasti = -1;
|
||||
for (offset = 0; offset < lnotab_len; offset += 2) {
|
||||
addr += lnotab[offset];
|
||||
line += lnotab[offset+1];
|
||||
if (line >= new_lineno) {
|
||||
new_lasti = addr;
|
||||
new_lineno = line;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
/* If we didn't reach the requested line, return an error. */
|
||||
if (new_lasti == -1) {
|
||||
PyErr_Format(PyExc_ValueError,
|
||||
"line %d comes after the current code block",
|
||||
new_lineno);
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* We're now ready to look at the bytecode. */
|
||||
PyString_AsStringAndSize(f->f_code->co_code, &code, &code_len);
|
||||
min_addr = MIN(new_lasti, f->f_lasti);
|
||||
max_addr = MAX(new_lasti, f->f_lasti);
|
||||
|
||||
/* You can't jump onto a line with an 'except' statement on it -
|
||||
* they expect to have an exception on the top of the stack, which
|
||||
* won't be true if you jump to them. They always start with code
|
||||
* that either pops the exception using POP_TOP (plain 'except:'
|
||||
* lines do this) or duplicates the exception on the stack using
|
||||
* DUP_TOP (if there's an exception type specified). See compile.c,
|
||||
* 'com_try_except' for the full details. There aren't any other
|
||||
* cases (AFAIK) where a line's code can start with DUP_TOP or
|
||||
* POP_TOP, but if any ever appear, they'll be subject to the same
|
||||
* restriction (but with a different error message). */
|
||||
if (code[new_lasti] == DUP_TOP || code[new_lasti] == POP_TOP) {
|
||||
PyErr_SetString(PyExc_ValueError,
|
||||
"can't jump to 'except' line as there's no exception");
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* You can't jump into or out of a 'finally' block because the 'try'
|
||||
* block leaves something on the stack for the END_FINALLY to clean
|
||||
* up. So we walk the bytecode, maintaining a simulated blockstack.
|
||||
* When we reach the old or new address and it's in a 'finally' block
|
||||
* we note the address of the corresponding SETUP_FINALLY. The jump
|
||||
* is only legal if neither address is in a 'finally' block or
|
||||
* they're both in the same one. 'blockstack' is a stack of the
|
||||
* bytecode addresses of the SETUP_X opcodes, and 'in_finally' tracks
|
||||
* whether we're in a 'finally' block at each blockstack level. */
|
||||
f_lasti_setup_addr = -1;
|
||||
new_lasti_setup_addr = -1;
|
||||
memset(blockstack, '\0', sizeof(blockstack));
|
||||
memset(in_finally, '\0', sizeof(in_finally));
|
||||
blockstack_top = 0;
|
||||
for (addr = 0; addr < code_len; addr++) {
|
||||
unsigned char op = code[addr];
|
||||
switch (op) {
|
||||
case SETUP_LOOP:
|
||||
case SETUP_EXCEPT:
|
||||
case SETUP_FINALLY:
|
||||
blockstack[blockstack_top++] = addr;
|
||||
in_finally[blockstack_top-1] = 0;
|
||||
break;
|
||||
|
||||
case POP_BLOCK:
|
||||
setup_op = code[blockstack[blockstack_top-1]];
|
||||
if (setup_op == SETUP_FINALLY) {
|
||||
in_finally[blockstack_top-1] = 1;
|
||||
}
|
||||
else {
|
||||
blockstack_top--;
|
||||
}
|
||||
break;
|
||||
|
||||
case END_FINALLY:
|
||||
/* Ignore END_FINALLYs for SETUP_EXCEPTs - they exist
|
||||
* in the bytecode but don't correspond to an actual
|
||||
* 'finally' block. */
|
||||
setup_op = code[blockstack[blockstack_top-1]];
|
||||
if (setup_op == SETUP_FINALLY) {
|
||||
blockstack_top--;
|
||||
}
|
||||
break;
|
||||
}
|
||||
|
||||
/* For the addresses we're interested in, see whether they're
|
||||
* within a 'finally' block and if so, remember the address
|
||||
* of the SETUP_FINALLY. */
|
||||
if (addr == new_lasti || addr == f->f_lasti) {
|
||||
int i = 0;
|
||||
int setup_addr = -1;
|
||||
for (i = blockstack_top-1; i >= 0; i--) {
|
||||
if (in_finally[i]) {
|
||||
setup_addr = blockstack[i];
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
if (setup_addr != -1) {
|
||||
if (addr == new_lasti) {
|
||||
new_lasti_setup_addr = setup_addr;
|
||||
}
|
||||
|
||||
if (addr == f->f_lasti) {
|
||||
f_lasti_setup_addr = setup_addr;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if (op >= HAVE_ARGUMENT) {
|
||||
addr += 2;
|
||||
}
|
||||
}
|
||||
|
||||
if (new_lasti_setup_addr != f_lasti_setup_addr) {
|
||||
PyErr_SetString(PyExc_ValueError,
|
||||
"can't jump into or out of a 'finally' block");
|
||||
return -1;
|
||||
}
|
||||
|
||||
|
||||
/* Police block-jumping (you can't jump into the middle of a block)
|
||||
* and ensure that the blockstack finishes up in a sensible state (by
|
||||
* popping any blocks we're jumping out of). We look at all the
|
||||
* blockstack operations between the current position and the new
|
||||
* one, and keep track of how many blocks we drop out of on the way.
|
||||
* By also keeping track of the lowest blockstack position we see, we
|
||||
* can tell whether the jump goes into any blocks without coming out
|
||||
* again - in that case we raise an exception below. */
|
||||
delta_iblock = 0;
|
||||
for (addr = min_addr; addr < max_addr; addr++) {
|
||||
unsigned char op = code[addr];
|
||||
switch (op) {
|
||||
case SETUP_LOOP:
|
||||
case SETUP_EXCEPT:
|
||||
case SETUP_FINALLY:
|
||||
delta_iblock++;
|
||||
break;
|
||||
|
||||
case POP_BLOCK:
|
||||
delta_iblock--;
|
||||
break;
|
||||
}
|
||||
|
||||
min_delta_iblock = MIN(min_delta_iblock, delta_iblock);
|
||||
|
||||
if (op >= HAVE_ARGUMENT) {
|
||||
addr += 2;
|
||||
}
|
||||
}
|
||||
|
||||
/* Derive the absolute iblock values from the deltas. */
|
||||
min_iblock = f->f_iblock + min_delta_iblock;
|
||||
if (new_lasti > f->f_lasti) {
|
||||
/* Forwards jump. */
|
||||
new_iblock = f->f_iblock + delta_iblock;
|
||||
}
|
||||
else {
|
||||
/* Backwards jump. */
|
||||
new_iblock = f->f_iblock - delta_iblock;
|
||||
}
|
||||
|
||||
/* Are we jumping into a block? */
|
||||
if (new_iblock > min_iblock) {
|
||||
PyErr_SetString(PyExc_ValueError,
|
||||
"can't jump into the middle of a block");
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* Pop any blocks that we're jumping out of. */
|
||||
while (f->f_iblock > new_iblock) {
|
||||
PyTryBlock *b = &f->f_blockstack[--f->f_iblock];
|
||||
while ((f->f_stacktop - f->f_valuestack) > b->b_level) {
|
||||
PyObject *v = (*--f->f_stacktop);
|
||||
Py_DECREF(v);
|
||||
}
|
||||
}
|
||||
|
||||
/* Finally set the new f_lineno and f_lasti and return OK. */
|
||||
f->f_lineno = new_lineno;
|
||||
f->f_lasti = new_lasti;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static PyObject *
|
||||
frame_gettrace(PyFrameObject *f, void *closure)
|
||||
{
|
||||
|
|
@ -77,7 +334,8 @@ frame_settrace(PyFrameObject *f, PyObject* v, void *closure)
|
|||
|
||||
static PyGetSetDef frame_getsetlist[] = {
|
||||
{"f_locals", (getter)frame_getlocals, NULL, NULL},
|
||||
{"f_lineno", (getter)frame_getlineno, NULL, NULL},
|
||||
{"f_lineno", (getter)frame_getlineno,
|
||||
(setter)frame_setlineno, NULL},
|
||||
{"f_trace", (getter)frame_gettrace, (setter)frame_settrace, NULL},
|
||||
{0}
|
||||
};
|
||||
|
|
|
|||
Loading…
Reference in New Issue