When the return value of yield wasn't used it was leaked.
This is fixed by using a TMP_VAR return value instead of VAR. TMP_VARs are
automatically freed when they aren't used.
The code did not check whether the zend_hash_index_find calls succeded,
so PHP crashed when an array callback was called that contains two elements
which don't have the indices 0 and 1.
Generators follow a different cleanup path, so the extra check for freeing
the execute_data is unnecessary there. It actually caused problems because
op_array->fn_flags could be in freed memory at that time (in case op_array
came from a closure in an ArrayAccess container).
This fixes the valgrind warning in Zend/tests/bug54367.phpt.
* Trying to resume a generator while it is already running now throws a
fatal error.
* Trying to use yield in finally while the generator is being force-closed
(by GC) throws a fatal error.
* Rewinding after the first yield now throws an Exception
The finally clause is now properly run when an exception is thrown in the
try-block. It is not yet run on `return` and also not run when the generator
is claused within a try block.
I'll add those two things as soon as laruence refactored the finally code.
This is just an intial merge. It does not yet make generators and finally
work together.
Conflicts:
Zend/zend_language_scanner.c
Zend/zend_language_scanner_defs.h
Zend/zend_vm_def.h
Zend/zend_vm_execute.h
Zend/zend_vm_execute.skl
Zend/zend_vm_opcodes.h
the reason why jpauli and I can not reproduce is (it's silly):
I typo "USE_ZEND_ALLOC *&&* valgrind" at the first time, then I always ctrl+r
and jpauli copied my command from the pastbin :)
thanks
If a generator threw an exception and was iterated using foreach (i.e. not
manually) an infinite loop was triggered. The reason was that the exception
was not properly rethrown using zend_throw_exception_internal.
Generators are now automatically detected by the presence of a `yield`
expression in their body.
This removes the ZEND_SUSPEND_AND_RETURN_GENERATOR opcode. Instead
additional checks for ZEND_ACC_GENERATOR are added to the fcall_common
helper and zend_call_function.
This also adds a new function zend_generator_create_zval, which handles
the actual creation of the generator zval from an op array.
I feel like I should deglobalize the zend_create_execute_data_from_op_array
code a bit. It currently changes EG(current_execute_data) and
EG(opline_ptr) which is somewhat confusing (given the name).
Previously the zval* of the generator was passed into the VM by misusing
EG(return_value_ptr_ptr). Now the zend_generator* itself is directly passed
in. This saves us from always having to pass the zval* around everywhere.
To make the generator function show up in backtraces one has to insert an
additional execute_data into the chain, as prev_execute_data->function_state
is used to determine the called function.
Adding the additional stack frame is also required for func_get_args(), as
the arguments are fetched from there too. The arguments have to be copied
in order to keep them around. Due to the way they are saved doing so is
quite ugly, so I added another function zend_copy_arguments to zend_execute.c
which handles this.
During function calls arguments are pushed onto the stack. Now these are
backed up on yield and restored on resume. This requires memcpy'ing them,
but there doesn't seem to be any better way to do it.
Also this fixes the issue with exceptions thrown during function calls.
The missing piece is how one can find the next stack frame, which is
required for dtor'ing arguments pushed to the stack. As the generator
execute_data does not live on the stack one can't use it to figure out the
start of the next stack frame. So there must be some other method.