Commit 48caa09a authored by Paul Sokolovsky's avatar Paul Sokolovsky
Browse files

objgenerator: Implement .throw() method to throw exceptions into generator.

parent 61fd20f1
......@@ -15,5 +15,5 @@ typedef struct _mp_exc_stack {
} mp_exc_stack;
mp_vm_return_kind_t mp_execute_byte_code(const byte *code, const mp_obj_t *args, uint n_args, const mp_obj_t *args2, uint n_args2, uint n_state, mp_obj_t *ret);
mp_vm_return_kind_t mp_execute_byte_code_2(const byte *code_info, const byte **ip_in_out, mp_obj_t *fastn, mp_obj_t **sp_in_out, mp_exc_stack *exc_stack, mp_exc_stack **exc_sp_in_out);
mp_vm_return_kind_t mp_execute_byte_code_2(const byte *code_info, const byte **ip_in_out, mp_obj_t *fastn, mp_obj_t **sp_in_out, mp_exc_stack *exc_stack, mp_exc_stack **exc_sp_in_out, volatile mp_obj_t inject_exc);
void mp_byte_code_print(const byte *code, int len);
......@@ -70,7 +70,7 @@ mp_obj_t gen_instance_getiter(mp_obj_t self_in) {
return self_in;
}
STATIC mp_obj_t gen_next_send(mp_obj_t self_in, mp_obj_t send_value) {
STATIC mp_obj_t gen_resume(mp_obj_t self_in, mp_obj_t send_value, mp_obj_t throw_value) {
mp_obj_gen_instance_t *self = self_in;
if (self->ip == 0) {
return mp_const_stop_iteration;
......@@ -83,7 +83,8 @@ STATIC mp_obj_t gen_next_send(mp_obj_t self_in, mp_obj_t send_value) {
*self->sp = send_value;
}
mp_vm_return_kind_t vm_return_kind = mp_execute_byte_code_2(self->code_info, &self->ip,
&self->state[self->n_state - 1], &self->sp, (mp_exc_stack*)(self->state + self->n_state), &self->exc_sp);
&self->state[self->n_state - 1], &self->sp, (mp_exc_stack*)(self->state + self->n_state),
&self->exc_sp, throw_value);
switch (vm_return_kind) {
case MP_VM_RETURN_NORMAL:
// Explicitly mark generator as completed. If we don't do this,
......@@ -113,11 +114,11 @@ STATIC mp_obj_t gen_next_send(mp_obj_t self_in, mp_obj_t send_value) {
}
mp_obj_t gen_instance_iternext(mp_obj_t self_in) {
return gen_next_send(self_in, mp_const_none);
return gen_resume(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_next_send(self_in, send_value);
mp_obj_t ret = gen_resume(self_in, send_value, MP_OBJ_NULL);
if (ret == mp_const_stop_iteration) {
nlr_jump(mp_obj_new_exception(&mp_type_StopIteration));
} else {
......@@ -127,8 +128,21 @@ STATIC mp_obj_t gen_instance_send(mp_obj_t self_in, mp_obj_t send_value) {
STATIC MP_DEFINE_CONST_FUN_OBJ_2(gen_instance_send_obj, gen_instance_send);
STATIC mp_obj_t gen_instance_throw(uint n_args, const mp_obj_t *args) {
mp_obj_t ret = gen_resume(args[0], mp_const_none, n_args == 2 ? args[1] : args[2]);
if (ret == mp_const_stop_iteration) {
nlr_jump(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 const mp_method_t gen_type_methods[] = {
{ "send", &gen_instance_send_obj },
{ "throw", &gen_instance_throw_obj },
{ NULL, NULL }, // end-of-list sentinel
};
......
......@@ -82,7 +82,7 @@ mp_vm_return_kind_t mp_execute_byte_code(const byte *code, const mp_obj_t *args,
mp_exc_stack exc_stack[4];
mp_exc_stack *exc_sp = &exc_stack[0] - 1;
// execute the byte code
mp_vm_return_kind_t vm_return_kind = mp_execute_byte_code_2(code, &ip, &state[n_state - 1], &sp, exc_stack, &exc_sp);
mp_vm_return_kind_t vm_return_kind = mp_execute_byte_code_2(code, &ip, &state[n_state - 1], &sp, exc_stack, &exc_sp, MP_OBJ_NULL);
switch (vm_return_kind) {
case MP_VM_RETURN_NORMAL:
......@@ -107,8 +107,8 @@ mp_vm_return_kind_t mp_execute_byte_code(const byte *code, const mp_obj_t *args,
// MP_VM_RETURN_EXCEPTION, exception in fastn[0]
mp_vm_return_kind_t mp_execute_byte_code_2(const byte *code_info, const byte **ip_in_out,
mp_obj_t *fastn, mp_obj_t **sp_in_out,
mp_exc_stack *exc_stack,
mp_exc_stack **exc_sp_in_out) {
mp_exc_stack *exc_stack, mp_exc_stack **exc_sp_in_out,
volatile mp_obj_t inject_exc) {
// careful: be sure to declare volatile any variables read in the exception handler (written is ok, I think)
const byte *ip = *ip_in_out;
......@@ -118,13 +118,21 @@ mp_vm_return_kind_t mp_execute_byte_code_2(const byte *code_info, const byte **i
mp_obj_t obj1, obj2;
nlr_buf_t nlr;
volatile machine_uint_t currently_in_except_block = 0; // 0 or 1, to detect nested exceptions
mp_exc_stack *volatile exc_sp = *exc_sp_in_out; // stack grows up, exc_sp points to top of stack
volatile machine_uint_t currently_in_except_block = (int)*exc_sp_in_out & 1; // 0 or 1, to detect nested exceptions
mp_exc_stack *volatile exc_sp = (void*)((int)*exc_sp_in_out & ~1); // stack grows up, exc_sp points to top of stack
const byte *volatile save_ip = ip; // this is so we can access ip in the exception handler without making ip volatile (which means the compiler can't keep it in a register in the main loop)
// outer exception handling loop
for (;;) {
if (nlr_push(&nlr) == 0) {
// If we have exception to inject, now that we finish setting up
// execution context, raise it. This works as if RAISE_VARARGS
// bytecode was executed.
if (inject_exc != MP_OBJ_NULL) {
mp_obj_t t = inject_exc;
inject_exc = MP_OBJ_NULL;
nlr_jump(rt_make_raise_obj(t));
}
// loop to execute byte code
for (;;) {
dispatch_loop:
......@@ -599,7 +607,7 @@ unwind_return:
nlr_pop();
*ip_in_out = ip;
*sp_in_out = sp;
*exc_sp_in_out = exc_sp;
*exc_sp_in_out = (void*)((int)exc_sp | currently_in_except_block);
return MP_VM_RETURN_YIELD;
case MP_BC_IMPORT_NAME:
......
......@@ -29,3 +29,25 @@ try:
print(next(g))
except StopIteration:
print("StopIteration")
# Test throwing exception into generator
def gen3():
yield 1
try:
yield 2
except ValueError:
print("ValueError received")
yield 3
yield 4
yield 5
g = gen3()
print(next(g))
print(next(g))
print("out of throw:", g.throw(ValueError))
print(next(g))
try:
print("out of throw2:", g.throw(ValueError))
except ValueError:
print("Boomerang ValueError caught")
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