update comments

This commit is contained in:
Benjamin Peterson 2009-06-28 15:55:46 +00:00
parent 176101d660
commit fec42da1ab
1 changed files with 12 additions and 5 deletions

View File

@ -2491,20 +2491,23 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
- (TOP, SECOND) = (WHY_{RETURN,CONTINUE}), retval - (TOP, SECOND) = (WHY_{RETURN,CONTINUE}), retval
- TOP = WHY_*; no retval below it - TOP = WHY_*; no retval below it
- (TOP, SECOND, THIRD) = exc_info() - (TOP, SECOND, THIRD) = exc_info()
(FOURTH, FITH, SIXTH) = previous exception for EXCEPT_HANDLER
Below them is EXIT, the context.__exit__ bound method. Below them is EXIT, the context.__exit__ bound method.
In the last case, we must call In the last case, we must call
EXIT(TOP, SECOND, THIRD) EXIT(TOP, SECOND, THIRD)
otherwise we must call otherwise we must call
EXIT(None, None, None) EXIT(None, None, None)
In all cases, we remove EXIT from the stack, leaving In the first two cases, we remove EXIT from the
the rest in the same order. stack, leaving the rest in the same order. In the
third case, we shift the bottom 3 values of the
stack down, and replace the empty spot with NULL.
In addition, if the stack represents an exception, In addition, if the stack represents an exception,
*and* the function call returns a 'true' value, we *and* the function call returns a 'true' value, we
"zap" this information, to prevent END_FINALLY from push WHY_SILENCED onto the stack. END_FINALLY will
re-raising the exception. (But non-local gotos then not re-raise the exception. (But non-local
should still be resumed.) gotos should still be resumed.)
*/ */
PyObject *exit_func; PyObject *exit_func;
@ -2544,7 +2547,11 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
stack_pointer[-7] = tb; stack_pointer[-7] = tb;
stack_pointer[-6] = exc; stack_pointer[-6] = exc;
stack_pointer[-5] = tp; stack_pointer[-5] = tp;
/* UNWIND_EXCEPT_BLOCK will pop this off. */
FOURTH() = NULL; FOURTH() = NULL;
/* We just shifted the stack down, so we have
to tell the except handler block that the
values are lower than it expects. */
block = &f->f_blockstack[f->f_iblock - 1]; block = &f->f_blockstack[f->f_iblock - 1];
assert(block->b_type == EXCEPT_HANDLER); assert(block->b_type == EXCEPT_HANDLER);
block->b_level--; block->b_level--;