missing frame.f_lineno on JUMP_ABSOLUTE #91241

Activity

1. graingert commented on Mar 21, 2022

   

   graingertmannequin

   on Mar 21, 2022

   MannequinAuthor

   More actions

   the following code prints:

   import sys
   import dis
   
   import pprint
   
   def demo():
       for i in range(1):
           if i >= 0:
               pass
   
   
   class Tracer:
       def __init__(self):
           self.events = []
   
       def trace(self, frame, event, arg):
           self.events.append((frame.f_lineno, frame.f_lasti, event))
           frame.f_trace_lines = True
           frame.f_trace_opcodes = True
           return self.trace
   
   def main():
       t = Tracer()
       old_trace = sys.gettrace()
       try:
           sys.settrace(t.trace)
           demo()
       finally:
           sys.settrace(old_trace)
       dis.dis(demo)
       pprint.pp(t.events)
   
   
   if __name__ == "__main__":
       sys.exit(main())

   7 0 LOAD_GLOBAL 0 (range)
   2 LOAD_CONST 1 (1)
   4 CALL_FUNCTION 1
   6 GET_ITER
   >> 8 FOR_ITER 7 (to 24)
   10 STORE_FAST 0 (i)

   8 12 LOAD_FAST 0 (i)
   14 LOAD_CONST 2 (0)
   16 COMPARE_OP 5 (>=)
   18 POP_JUMP_IF_FALSE 11 (to 22)

   9 20 NOP
   >> 22 JUMP_ABSOLUTE 4 (to 8)

   7 >> 24 LOAD_CONST 0 (None)
   26 RETURN_VALUE
   [(6, -1, 'call'),
   (7, 0, 'line'),
   (7, 0, 'opcode'),
   (7, 2, 'opcode'),
   (7, 4, 'opcode'),
   (7, 6, 'opcode'),
   (7, 8, 'opcode'),
   (7, 10, 'opcode'),
   (8, 12, 'line'),
   (8, 12, 'opcode'),
   (8, 14, 'opcode'),
   (8, 16, 'opcode'),
   (8, 18, 'opcode'),
   (9, 20, 'line'),
   (9, 20, 'opcode'),
   (None, 22, 'opcode'),
   (7, 8, 'line'),
   (7, 8, 'opcode'),
   (7, 24, 'opcode'),
   (7, 26, 'opcode'),
   (7, 26, 'return')]

   but I'd expect (9, 22, 'opcode') instead of (None, 22, 'opcode'),
2. graingert

   added

   3.10 (EOL)end of lifeend of life

   3.11only security fixesonly security fixes

   on Mar 21, 2022
3. markshannon commented on Mar 22, 2022

   

   markshannon

   on Mar 22, 2022

   Member

   More actions

   The JUMP_ABSOLUTE doesn't have a line number, as it doesn't correspond to any source.

   The jump back to the top could follow either the `if i >= 0:` or the `pass`, so cannot have a line number.

   Don't expect every bytecode to map directly back to the source, especially if it cannot raise an exception.

   Per-line tracing is well defined by PEP-626. Per-opcode tracing is not.
4. markshannon

   closed this as completedon Mar 22, 2022
5. markshannon

   added

   invalid

   on Mar 22, 2022
6. ezio-melotti

   transferred this issue fromon Apr 10, 2022
7. graingert commented on Jul 19, 2022

   

   graingert

   on Jul 19, 2022

   Last edited by graingert

   ContributorAuthor

   More actions

   looks like this was fixed by ddc4a78 #93229