circuitpython/py/objgenerator.c

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#include <stdlib.h>
#include <assert.h>
#include "mpconfig.h"
#include "nlr.h"
#include "misc.h"
#include "qstr.h"
#include "obj.h"
#include "runtime.h"
#include "bc.h"
#include "objgenerator.h"
#include "objfun.h"
/******************************************************************************/
/* generator wrapper */
typedef struct _mp_obj_gen_wrap_t {
mp_obj_base_t base;
mp_obj_t *fun;
} mp_obj_gen_wrap_t;
mp_obj_t mp_obj_new_gen_instance(mp_obj_dict_t *globals, const byte *bytecode, uint n_args, const mp_obj_t *args,
uint n_args2, const mp_obj_t *args2);
STATIC mp_obj_t gen_wrap_call(mp_obj_t self_in, uint n_args, uint n_kw, const mp_obj_t *args) {
mp_obj_gen_wrap_t *self = self_in;
mp_obj_fun_bc_t *self_fun = (mp_obj_fun_bc_t*)self->fun;
assert(MP_OBJ_IS_TYPE(self_fun, &mp_type_fun_bc));
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const mp_obj_t *args1, *args2;
uint len1, len2;
if (!mp_obj_fun_prepare_simple_args(self_fun, n_args, n_kw, args, &len1, &args1, &len2, &args2)) {
assert(0);
}
return mp_obj_new_gen_instance(self_fun->globals, self_fun->bytecode, len1, args1, len2, args2);
}
const mp_obj_type_t mp_type_gen_wrap = {
{ &mp_type_type },
.name = MP_QSTR_generator,
.call = gen_wrap_call,
};
mp_obj_t mp_obj_new_gen_wrap(mp_obj_t fun) {
mp_obj_gen_wrap_t *o = m_new_obj(mp_obj_gen_wrap_t);
o->base.type = &mp_type_gen_wrap;
o->fun = fun;
return o;
}
/******************************************************************************/
/* generator instance */
typedef struct _mp_obj_gen_instance_t {
mp_obj_base_t base;
mp_obj_dict_t *globals;
const byte *code_info;
const byte *ip;
mp_obj_t *sp;
// bit 0 is saved currently_in_except_block value
mp_exc_stack_t *exc_sp;
uint n_state;
// Variable-length
mp_obj_t state[0];
// Variable-length, never accessed by name, only as (void*)(state + n_state)
mp_exc_stack_t exc_state[0];
} mp_obj_gen_instance_t;
void gen_instance_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
mp_obj_gen_instance_t *self = self_in;
print(env, "<generator object '%s' at %p>", mp_obj_code_get_name(self->code_info), self_in);
}
mp_obj_t gen_instance_getiter(mp_obj_t self_in) {
return self_in;
}
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) {
assert(MP_OBJ_IS_TYPE(self_in, &mp_type_gen_instance));
mp_obj_gen_instance_t *self = self_in;
if (self->ip == 0) {
*ret_val = MP_OBJ_STOP_ITERATION;
return MP_VM_RETURN_NORMAL;
}
if (self->sp == self->state - 1) {
if (send_value != mp_const_none) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "can't send non-None value to a just-started generator"));
}
} else {
*self->sp = send_value;
}
mp_obj_dict_t *old_globals = mp_globals_get();
mp_globals_set(self->globals);
mp_vm_return_kind_t ret_kind = mp_execute_byte_code_2(self->code_info, &self->ip,
&self->state[self->n_state - 1], &self->sp, (mp_exc_stack_t*)(self->state + self->n_state),
&self->exc_sp, throw_value);
mp_globals_set(old_globals);
switch (ret_kind) {
case MP_VM_RETURN_NORMAL:
// 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.
// TODO: check how return with value behaves under such conditions
// in CPython.
self->ip = 0;
*ret_val = *self->sp;
break;
case MP_VM_RETURN_YIELD:
*ret_val = *self->sp;
break;
case MP_VM_RETURN_EXCEPTION:
self->ip = 0;
*ret_val = self->state[self->n_state - 1];
break;
default:
assert(0);
*ret_val = mp_const_none;
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:
// 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:
if (throw_value != MP_OBJ_NULL && mp_obj_is_subclass_fast(mp_obj_get_type(throw_value), &mp_type_GeneratorExit)) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_RuntimeError, "generator ignored GeneratorExit"));
}
return ret;
case MP_VM_RETURN_EXCEPTION:
// TODO: Optimization of returning MP_OBJ_STOP_ITERATION is really part
// of mp_iternext() protocol, but this function is called by other methods
// too, which may not handled MP_OBJ_STOP_ITERATION.
if (mp_obj_is_subclass_fast(mp_obj_get_type(ret), &mp_type_StopIteration)) {
return MP_OBJ_STOP_ITERATION;
} else {
nlr_raise(ret);
}
default:
assert(0);
return mp_const_none;
}
}
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(uint n_args, const mp_obj_t *args) {
mp_obj_t exc = (n_args == 2) ? args[1] : args[2];
exc = mp_make_raise_obj(exc);
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_t)&mp_const_GeneratorExit_obj, &ret)) {
case MP_VM_RETURN_YIELD:
nlr_raise(mp_obj_new_exception_msg(&mp_type_RuntimeError, "generator ignored GeneratorExit"));
// Swallow StopIteration & 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_get_type(ret), &mp_type_GeneratorExit) ||
mp_obj_is_subclass_fast(mp_obj_get_type(ret), &mp_type_StopIteration)) {
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 const mp_map_elem_t gen_instance_locals_dict_table[] = {
{ MP_OBJ_NEW_QSTR(MP_QSTR_close), (mp_obj_t)&gen_instance_close_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_send), (mp_obj_t)&gen_instance_send_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_throw), (mp_obj_t)&gen_instance_throw_obj },
};
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,
.getiter = gen_instance_getiter,
.iternext = gen_instance_iternext,
.locals_dict = (mp_obj_t)&gen_instance_locals_dict,
};
mp_obj_t mp_obj_new_gen_instance(mp_obj_dict_t *globals, const byte *bytecode, uint n_args, const mp_obj_t *args,
uint n_args2, const mp_obj_t *args2) {
const byte *code_info = bytecode;
// get code info size, and skip the line number table
machine_uint_t code_info_size = bytecode[0] | (bytecode[1] << 8) | (bytecode[2] << 16) | (bytecode[3] << 24);
bytecode += code_info_size;
// bytecode prelude: get state size and exception stack size
machine_uint_t n_state = bytecode[0] | (bytecode[1] << 8);
machine_uint_t n_exc_stack = bytecode[2] | (bytecode[3] << 8);
bytecode += 4;
// 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 = globals;
o->code_info = code_info;
o->sp = &o->state[0] - 1; // sp points to top of stack, which starts off 1 below the state
o->exc_sp = (mp_exc_stack_t*)(o->state + n_state) - 1;
o->n_state = n_state;
// copy args to end of state array, in reverse (that's how mp_execute_byte_code_2 needs it)
for (uint i = 0; i < n_args; i++) {
o->state[n_state - 1 - i] = args[i];
}
for (uint i = 0; i < n_args2; i++) {
o->state[n_state - 1 - n_args - i] = args2[i];
}
// set rest of state to MP_OBJ_NULL
for (uint i = 0; i < n_state - n_args - n_args2; i++) {
o->state[i] = MP_OBJ_NULL;
}
// bytecode prelude: initialise closed over variables
for (uint n_local = *bytecode++; n_local > 0; n_local--) {
uint local_num = *bytecode++;
o->state[n_state - 1 - local_num] = mp_obj_new_cell(o->state[n_state - 1 - local_num]);
}
// set ip to start of actual byte code
o->ip = bytecode;
return o;
}