circuitpython/py/objgenerator.c
Damien George cc2bd63c57 py/emitnative: Implement yield and yield-from in native emitter.
This commit adds first class support for yield and yield-from in the native
emitter, including send and throw support, and yields enclosed in exception
handlers (which requires pulling down the NLR stack before yielding, then
rebuilding it when resuming).

This has been fully tested and is working on unix x86 and x86-64, and
stm32.  Also basic tests have been done with the esp8266 port.  Performance
of existing native code is unchanged.
2018-10-01 13:31:11 +10:00

320 lines
12 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 Damien P. George
* Copyright (c) 2014-2017 Paul Sokolovsky
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <stdlib.h>
#include <assert.h>
#include "py/runtime.h"
#include "py/bc.h"
#include "py/objgenerator.h"
#include "py/objfun.h"
#include "py/stackctrl.h"
/******************************************************************************/
/* generator wrapper */
typedef struct _mp_obj_gen_instance_t {
mp_obj_base_t base;
mp_obj_dict_t *globals;
mp_code_state_t code_state;
} mp_obj_gen_instance_t;
STATIC mp_obj_t gen_wrap_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
// A generating function is just a bytecode function with type mp_type_gen_wrap
mp_obj_fun_bc_t *self_fun = MP_OBJ_TO_PTR(self_in);
// bytecode prelude: get state size and exception stack size
size_t n_state = mp_decode_uint_value(self_fun->bytecode);
size_t n_exc_stack = mp_decode_uint_value(mp_decode_uint_skip(self_fun->bytecode));
// allocate the generator object, with room for local stack and exception stack
mp_obj_gen_instance_t *o = m_new_obj_var(mp_obj_gen_instance_t, byte,
n_state * sizeof(mp_obj_t) + n_exc_stack * sizeof(mp_exc_stack_t));
o->base.type = &mp_type_gen_instance;
o->globals = self_fun->globals;
o->code_state.fun_bc = self_fun;
o->code_state.ip = 0;
mp_setup_code_state(&o->code_state, n_args, n_kw, args);
return MP_OBJ_FROM_PTR(o);
}
const mp_obj_type_t mp_type_gen_wrap = {
{ &mp_type_type },
.name = MP_QSTR_generator,
.call = gen_wrap_call,
.unary_op = mp_generic_unary_op,
#if MICROPY_PY_FUNCTION_ATTRS
.attr = mp_obj_fun_bc_attr,
#endif
};
/******************************************************************************/
// native generator wrapper
#if MICROPY_EMIT_NATIVE
STATIC mp_obj_t native_gen_wrap_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
// The state for a native generating function is held in the same struct as a bytecode function
mp_obj_fun_bc_t *self_fun = MP_OBJ_TO_PTR(self_in);
// Determine start of prelude, and extract n_state from it
uintptr_t prelude_offset = ((uintptr_t*)self_fun->bytecode)[0];
size_t n_state = mp_decode_uint_value(self_fun->bytecode + prelude_offset);
size_t n_exc_stack = 0;
// Allocate the generator object, with room for local stack and exception stack
mp_obj_gen_instance_t *o = m_new_obj_var(mp_obj_gen_instance_t, byte,
n_state * sizeof(mp_obj_t) + n_exc_stack * sizeof(mp_exc_stack_t));
o->base.type = &mp_type_gen_instance;
// Parse the input arguments and set up the code state
o->globals = self_fun->globals;
o->code_state.fun_bc = self_fun;
o->code_state.ip = (const byte*)prelude_offset;
mp_setup_code_state(&o->code_state, n_args, n_kw, args);
// Indicate we are a native function, which doesn't use this variable
o->code_state.exc_sp = NULL;
// Prepare the generator instance for execution
uintptr_t start_offset = ((uintptr_t*)self_fun->bytecode)[1];
o->code_state.ip = MICROPY_MAKE_POINTER_CALLABLE((void*)(self_fun->bytecode + start_offset));
return MP_OBJ_FROM_PTR(o);
}
const mp_obj_type_t mp_type_native_gen_wrap = {
{ &mp_type_type },
.name = MP_QSTR_generator,
.call = native_gen_wrap_call,
.unary_op = mp_generic_unary_op,
#if MICROPY_PY_FUNCTION_ATTRS
.attr = mp_obj_fun_bc_attr,
#endif
};
#endif // MICROPY_EMIT_NATIVE
/******************************************************************************/
/* generator instance */
STATIC void gen_instance_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
(void)kind;
mp_obj_gen_instance_t *self = MP_OBJ_TO_PTR(self_in);
mp_printf(print, "<generator object '%q' at %p>", mp_obj_fun_get_name(MP_OBJ_FROM_PTR(self->code_state.fun_bc)), self);
}
mp_vm_return_kind_t mp_obj_gen_resume(mp_obj_t self_in, mp_obj_t send_value, mp_obj_t throw_value, mp_obj_t *ret_val) {
MP_STACK_CHECK();
mp_check_self(MP_OBJ_IS_TYPE(self_in, &mp_type_gen_instance));
mp_obj_gen_instance_t *self = MP_OBJ_TO_PTR(self_in);
if (self->code_state.ip == 0) {
// Trying to resume already stopped generator
*ret_val = MP_OBJ_STOP_ITERATION;
return MP_VM_RETURN_NORMAL;
}
if (self->code_state.sp == self->code_state.state - 1) {
if (send_value != mp_const_none) {
mp_raise_TypeError("can't send non-None value to a just-started generator");
}
} else {
#if MICROPY_PY_GENERATOR_PEND_THROW
// If exception is pending (set using .pend_throw()), process it now.
if (*self->code_state.sp != mp_const_none) {
throw_value = *self->code_state.sp;
*self->code_state.sp = MP_OBJ_NULL;
} else
#endif
{
*self->code_state.sp = send_value;
}
}
// We set self->globals=NULL while executing, for a sentinel to ensure the generator
// cannot be reentered during execution
if (self->globals == NULL) {
mp_raise_ValueError("generator already executing");
}
// Set up the correct globals context for the generator and execute it
self->code_state.old_globals = mp_globals_get();
mp_globals_set(self->globals);
self->globals = NULL;
mp_vm_return_kind_t ret_kind;
#if MICROPY_EMIT_NATIVE
if (self->code_state.exc_sp == NULL) {
// A native generator, with entry point 2 words into the "bytecode" pointer
typedef uintptr_t (*mp_fun_native_gen_t)(void*, mp_obj_t);
mp_fun_native_gen_t fun = MICROPY_MAKE_POINTER_CALLABLE((const void*)(self->code_state.fun_bc->bytecode + 2 * sizeof(uintptr_t)));
ret_kind = fun((void*)&self->code_state, throw_value);
} else
#endif
{
// A bytecode generator
ret_kind = mp_execute_bytecode(&self->code_state, throw_value);
}
self->globals = mp_globals_get();
mp_globals_set(self->code_state.old_globals);
switch (ret_kind) {
case MP_VM_RETURN_NORMAL:
default:
// Explicitly mark generator as completed. If we don't do this,
// subsequent next() may re-execute statements after last yield
// again and again, leading to side effects.
self->code_state.ip = 0;
*ret_val = *self->code_state.sp;
break;
case MP_VM_RETURN_YIELD:
*ret_val = *self->code_state.sp;
#if MICROPY_PY_GENERATOR_PEND_THROW
*self->code_state.sp = mp_const_none;
#endif
break;
case MP_VM_RETURN_EXCEPTION: {
self->code_state.ip = 0;
*ret_val = self->code_state.state[0];
// PEP479: if StopIteration is raised inside a generator it is replaced with RuntimeError
if (mp_obj_is_subclass_fast(MP_OBJ_FROM_PTR(mp_obj_get_type(*ret_val)), MP_OBJ_FROM_PTR(&mp_type_StopIteration))) {
*ret_val = mp_obj_new_exception_msg(&mp_type_RuntimeError, "generator raised StopIteration");
}
break;
}
}
return ret_kind;
}
STATIC mp_obj_t gen_resume_and_raise(mp_obj_t self_in, mp_obj_t send_value, mp_obj_t throw_value) {
mp_obj_t ret;
switch (mp_obj_gen_resume(self_in, send_value, throw_value, &ret)) {
case MP_VM_RETURN_NORMAL:
default:
// Optimize return w/o value in case generator is used in for loop
if (ret == mp_const_none || ret == MP_OBJ_STOP_ITERATION) {
return MP_OBJ_STOP_ITERATION;
} else {
nlr_raise(mp_obj_new_exception_args(&mp_type_StopIteration, 1, &ret));
}
case MP_VM_RETURN_YIELD:
return ret;
case MP_VM_RETURN_EXCEPTION:
nlr_raise(ret);
}
}
STATIC mp_obj_t gen_instance_iternext(mp_obj_t self_in) {
return gen_resume_and_raise(self_in, mp_const_none, MP_OBJ_NULL);
}
STATIC mp_obj_t gen_instance_send(mp_obj_t self_in, mp_obj_t send_value) {
mp_obj_t ret = gen_resume_and_raise(self_in, send_value, MP_OBJ_NULL);
if (ret == MP_OBJ_STOP_ITERATION) {
nlr_raise(mp_obj_new_exception(&mp_type_StopIteration));
} else {
return ret;
}
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(gen_instance_send_obj, gen_instance_send);
STATIC mp_obj_t gen_instance_close(mp_obj_t self_in);
STATIC mp_obj_t gen_instance_throw(size_t n_args, const mp_obj_t *args) {
mp_obj_t exc = (n_args == 2) ? args[1] : args[2];
mp_obj_t ret = gen_resume_and_raise(args[0], mp_const_none, exc);
if (ret == MP_OBJ_STOP_ITERATION) {
nlr_raise(mp_obj_new_exception(&mp_type_StopIteration));
} else {
return ret;
}
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(gen_instance_throw_obj, 2, 4, gen_instance_throw);
STATIC mp_obj_t gen_instance_close(mp_obj_t self_in) {
mp_obj_t ret;
switch (mp_obj_gen_resume(self_in, mp_const_none, MP_OBJ_FROM_PTR(&mp_const_GeneratorExit_obj), &ret)) {
case MP_VM_RETURN_YIELD:
mp_raise_msg(&mp_type_RuntimeError, "generator ignored GeneratorExit");
// Swallow GeneratorExit (== successful close), and re-raise any other
case MP_VM_RETURN_EXCEPTION:
// ret should always be an instance of an exception class
if (mp_obj_is_subclass_fast(MP_OBJ_FROM_PTR(mp_obj_get_type(ret)), MP_OBJ_FROM_PTR(&mp_type_GeneratorExit))) {
return mp_const_none;
}
nlr_raise(ret);
default:
// The only choice left is MP_VM_RETURN_NORMAL which is successful close
return mp_const_none;
}
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(gen_instance_close_obj, gen_instance_close);
STATIC mp_obj_t gen_instance_pend_throw(mp_obj_t self_in, mp_obj_t exc_in) {
mp_obj_gen_instance_t *self = MP_OBJ_TO_PTR(self_in);
if (self->code_state.sp == self->code_state.state - 1) {
mp_raise_TypeError("can't pend throw to just-started generator");
}
mp_obj_t prev = *self->code_state.sp;
*self->code_state.sp = exc_in;
return prev;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(gen_instance_pend_throw_obj, gen_instance_pend_throw);
STATIC const mp_rom_map_elem_t gen_instance_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR_close), MP_ROM_PTR(&gen_instance_close_obj) },
{ MP_ROM_QSTR(MP_QSTR_send), MP_ROM_PTR(&gen_instance_send_obj) },
{ MP_ROM_QSTR(MP_QSTR_throw), MP_ROM_PTR(&gen_instance_throw_obj) },
#if MICROPY_PY_GENERATOR_PEND_THROW
{ MP_ROM_QSTR(MP_QSTR_pend_throw), MP_ROM_PTR(&gen_instance_pend_throw_obj) },
#endif
};
STATIC MP_DEFINE_CONST_DICT(gen_instance_locals_dict, gen_instance_locals_dict_table);
const mp_obj_type_t mp_type_gen_instance = {
{ &mp_type_type },
.name = MP_QSTR_generator,
.print = gen_instance_print,
.unary_op = mp_generic_unary_op,
.getiter = mp_identity_getiter,
.iternext = gen_instance_iternext,
.locals_dict = (mp_obj_dict_t*)&gen_instance_locals_dict,
};