Produce cleaner bytecode for 'with' and 'async with' by generating separate code for normal and exceptional paths. (#6641)
Remove BEGIN_FINALLY, END_FINALLY, CALL_FINALLY and POP_FINALLY bytecodes. Implement finally blocks by code duplication.
Reimplement frame.lineno setter using line numbers rather than bytecode offsets.
diff --git a/Doc/library/dis.rst b/Doc/library/dis.rst
index b5243d0..2b55486 100644
--- a/Doc/library/dis.rst
+++ b/Doc/library/dis.rst
@@ -706,50 +706,21 @@
popped values are used to restore the exception state.
-.. opcode:: POP_FINALLY (preserve_tos)
+.. opcode:: RERAISE
- Cleans up the value stack and the block stack. If *preserve_tos* is not
- ``0`` TOS first is popped from the stack and pushed on the stack after
- performing other stack operations:
+ Re-raises the exception currently on top of the stack.
- * If TOS is ``NULL`` or an integer (pushed by :opcode:`BEGIN_FINALLY`
- or :opcode:`CALL_FINALLY`) it is popped from the stack.
- * If TOS is an exception type (pushed when an exception has been raised)
- 6 values are popped from the stack, the last three popped values are
- used to restore the exception state. An exception handler block is
- removed from the block stack.
-
- It is similar to :opcode:`END_FINALLY`, but doesn't change the bytecode
- counter nor raise an exception. Used for implementing :keyword:`break`,
- :keyword:`continue` and :keyword:`return` in the :keyword:`finally` block.
-
- .. versionadded:: 3.8
+ .. versionadded:: 3.8
-.. opcode:: BEGIN_FINALLY
+.. opcode:: WITH_EXCEPT_START
- Pushes ``NULL`` onto the stack for using it in :opcode:`END_FINALLY`,
- :opcode:`POP_FINALLY`, :opcode:`WITH_CLEANUP_START` and
- :opcode:`WITH_CLEANUP_FINISH`. Starts the :keyword:`finally` block.
+ Calls the function in position 7 on the stack with the top three
+ items on the stack as arguments.
+ Used to implement the call ``context_manager.__exit__(*exc_info())`` when an exception
+ has occurred in a :keyword:`with` statement.
- .. versionadded:: 3.8
-
-
-.. opcode:: END_FINALLY
-
- Terminates a :keyword:`finally` clause. The interpreter recalls whether the
- exception has to be re-raised or execution has to be continued depending on
- the value of TOS.
-
- * If TOS is ``NULL`` (pushed by :opcode:`BEGIN_FINALLY`) continue from
- the next instruction. TOS is popped.
- * If TOS is an integer (pushed by :opcode:`CALL_FINALLY`), sets the
- bytecode counter to TOS. TOS is popped.
- * If TOS is an exception type (pushed when an exception has been raised)
- 6 values are popped from the stack, the first three popped values are
- used to re-raise the exception and the last three popped values are used
- to restore the exception state. An exception handler block is removed
- from the block stack.
+ .. versionadded:: 3.8
.. opcode:: LOAD_ASSERTION_ERROR
@@ -780,35 +751,6 @@
.. versionadded:: 3.2
-.. opcode:: WITH_CLEANUP_START
-
- Starts cleaning up the stack when a :keyword:`with` statement block exits.
-
- At the top of the stack are either ``NULL`` (pushed by
- :opcode:`BEGIN_FINALLY`) or 6 values pushed if an exception has been
- raised in the with block. Below is the context manager's
- :meth:`~object.__exit__` or :meth:`~object.__aexit__` bound method.
-
- If TOS is ``NULL``, calls ``SECOND(None, None, None)``,
- removes the function from the stack, leaving TOS, and pushes ``None``
- to the stack. Otherwise calls ``SEVENTH(TOP, SECOND, THIRD)``,
- shifts the bottom 3 values of the stack down, replaces the empty spot
- with ``NULL`` and pushes TOS. Finally pushes the result of the call.
-
-
-.. opcode:: WITH_CLEANUP_FINISH
-
- Finishes cleaning up the stack when a :keyword:`with` statement block exits.
-
- TOS is result of ``__exit__()`` or ``__aexit__()`` function call pushed
- by :opcode:`WITH_CLEANUP_START`. SECOND is ``None`` or an exception type
- (pushed when an exception has been raised).
-
- Pops two values from the stack. If SECOND is not None and TOS is true
- unwinds the EXCEPT_HANDLER block which was created when the exception
- was caught and pushes ``NULL`` to the stack.
-
-
All of the following opcodes use their arguments.
.. opcode:: STORE_NAME (namei)
@@ -1060,15 +1002,6 @@
stack. *delta* points to the finally block or the first except block.
-.. opcode:: CALL_FINALLY (delta)
-
- Pushes the address of the next instruction onto the stack and increments
- bytecode counter by *delta*. Used for calling the finally block as a
- "subroutine".
-
- .. versionadded:: 3.8
-
-
.. opcode:: LOAD_FAST (var_num)
Pushes a reference to the local ``co_varnames[var_num]`` onto the stack.