Commit 049a7a81 authored by Damien George's avatar Damien George
Browse files

py: Simplify function call of a bytecode object.

parent c06427c0
......@@ -248,12 +248,6 @@ arg_error:
STATIC mp_obj_t fun_bc_call(mp_obj_t self_in, uint n_args, uint n_kw, const mp_obj_t *args) {
// This function is pretty complicated. It's main aim is to be efficient in speed and RAM
// usage for the common case of positional only args.
//
// TODO Now that we allocate the state for the bytecode execution, we probably don't
// need extra_args anymore, and definitely don't need flat_args.
//
// TODO The following comment is obsolete and probably wrong:
// extra_args layout: def_args, var_arg tuple, kwonly args, var_kw dict
DEBUG_printf("Input n_args: %d, n_kw: %d\n", n_args, n_kw);
DEBUG_printf("Input pos args: ");
......@@ -263,9 +257,42 @@ STATIC mp_obj_t fun_bc_call(mp_obj_t self_in, uint n_args, uint n_kw, const mp_o
mp_obj_fun_bc_t *self = self_in;
DEBUG_printf("Func n_def_args: %d\n", self->n_def_args);
const byte *ip = self->bytecode;
// get code info size, and skip line number table
machine_uint_t code_info_size = ip[0] | (ip[1] << 8) | (ip[2] << 16) | (ip[3] << 24);
ip += code_info_size;
// bytecode prelude: state size and exception stack size; 16 bit uints
machine_uint_t n_state = ip[0] | (ip[1] << 8);
machine_uint_t n_exc_stack = ip[2] | (ip[3] << 8);
ip += 4;
#if VM_DETECT_STACK_OVERFLOW
n_state += 1;
#endif
// allocate state for locals and stack
uint state_size = n_state * sizeof(mp_obj_t) + n_exc_stack * sizeof(mp_exc_stack_t);
mp_code_state *code_state;
if (state_size > VM_MAX_STATE_ON_STACK) {
code_state = m_new_obj_var(mp_code_state, byte, state_size);
} else {
code_state = alloca(sizeof(mp_code_state) + state_size);
}
code_state->code_info = self->bytecode;
code_state->sp = &code_state->state[0] - 1;
code_state->exc_sp = (mp_exc_stack_t*)(code_state->state + n_state) - 1;
code_state->n_state = n_state;
// zero out the local stack to begin with
memset(code_state->state, 0, n_state * sizeof(*code_state->state));
const mp_obj_t *kwargs = args + n_args;
mp_obj_t *extra_args = self->extra_args + self->n_def_args + self->has_def_kw_args;
uint n_extra_args = 0;
// var_pos_kw_args points to the stack where the var-args tuple, and var-kw dict, should go (if they are needed)
mp_obj_t *var_pos_kw_args = &code_state->state[n_state - 1 - self->n_pos_args - self->n_kwonly_args];
// check positional arguments
......@@ -275,57 +302,53 @@ STATIC mp_obj_t fun_bc_call(mp_obj_t self_in, uint n_args, uint n_kw, const mp_o
fun_pos_args_mismatch(self, self->n_pos_args, n_args);
}
// put extra arguments in varargs tuple
*extra_args = mp_obj_new_tuple(n_args - self->n_pos_args, args + self->n_pos_args);
n_extra_args = 1;
*var_pos_kw_args-- = mp_obj_new_tuple(n_args - self->n_pos_args, args + self->n_pos_args);
n_args = self->n_pos_args;
} else {
if (self->takes_var_args) {
DEBUG_printf("passing empty tuple as *args\n");
*extra_args = mp_const_empty_tuple;
n_extra_args = 1;
*var_pos_kw_args-- = mp_const_empty_tuple;
}
// Apply processing and check below only if we don't have kwargs,
// otherwise, kw handling code below has own extensive checks.
if (n_kw == 0) {
if (n_kw == 0 && !self->has_def_kw_args) {
if (n_args >= self->n_pos_args - self->n_def_args) {
// given enough arguments, but may need to use some default arguments
extra_args -= self->n_pos_args - n_args;
n_extra_args += self->n_pos_args - n_args;
for (uint i = n_args; i < self->n_pos_args; i++) {
code_state->state[n_state - 1 - i] = self->extra_args[i - (self->n_pos_args - self->n_def_args)];
}
} else {
fun_pos_args_mismatch(self, self->n_pos_args - self->n_def_args, n_args);
}
}
}
// copy positional args into state
for (uint i = 0; i < n_args; i++) {
code_state->state[n_state - 1 - i] = args[i];
}
// check keyword arguments
if (n_kw != 0 || self->has_def_kw_args) {
// We cannot use dynamically-sized array here, because GCC indeed
// deallocates it on leaving defining scope (unlike most static stack allocs).
// So, we have 2 choices: allocate it unconditionally at the top of function
// (wastes stack), or use alloca which is guaranteed to dealloc on func exit.
//mp_obj_t flat_args[self->n_args];
mp_obj_t *flat_args = alloca((self->n_pos_args + self->n_kwonly_args) * sizeof(mp_obj_t));
for (int i = self->n_pos_args + self->n_kwonly_args - 1; i >= 0; i--) {
flat_args[i] = MP_OBJ_NULL;
}
memcpy(flat_args, args, sizeof(*args) * n_args);
DEBUG_printf("Initial args: ");
dump_args(flat_args, self->n_pos_args + self->n_kwonly_args);
dump_args(code_state->state + n_state - self->n_pos_args - self->n_kwonly_args, self->n_pos_args + self->n_kwonly_args);
mp_obj_t dict = MP_OBJ_NULL;
if (self->takes_kw_args) {
dict = mp_obj_new_dict(n_kw); // TODO: better go conservative with 0?
*var_pos_kw_args = dict;
}
for (uint i = 0; i < n_kw; i++) {
qstr arg_name = MP_OBJ_QSTR_VALUE(kwargs[2 * i]);
for (uint j = 0; j < self->n_pos_args + self->n_kwonly_args; j++) {
if (arg_name == self->args[j]) {
if (flat_args[j] != MP_OBJ_NULL) {
if (code_state->state[n_state - 1 - j] != MP_OBJ_NULL) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
"function got multiple values for argument '%s'", qstr_str(arg_name)));
}
flat_args[j] = kwargs[2 * i + 1];
code_state->state[n_state - 1 - j] = kwargs[2 * i + 1];
goto continue2;
}
}
......@@ -336,38 +359,40 @@ STATIC mp_obj_t fun_bc_call(mp_obj_t self_in, uint n_args, uint n_kw, const mp_o
mp_obj_dict_store(dict, kwargs[2 * i], kwargs[2 * i + 1]);
continue2:;
}
DEBUG_printf("Args with kws flattened: ");
dump_args(flat_args, self->n_pos_args + self->n_kwonly_args);
dump_args(code_state->state + n_state - self->n_pos_args - self->n_kwonly_args, self->n_pos_args + self->n_kwonly_args);
// Now fill in defaults for positional args
mp_obj_t *d = &flat_args[self->n_pos_args - 1];
// fill in defaults for positional args
mp_obj_t *d = &code_state->state[n_state - self->n_pos_args];
mp_obj_t *s = &self->extra_args[self->n_def_args - 1];
for (int i = self->n_def_args; i > 0; i--, d--, s--) {
for (int i = self->n_def_args; i > 0; i--, d++, s--) {
if (*d == MP_OBJ_NULL) {
*d = *s;
}
}
DEBUG_printf("Args after filling defaults: ");
dump_args(flat_args, self->n_pos_args + self->n_kwonly_args);
DEBUG_printf("Args after filling default positional: ");
dump_args(code_state->state + n_state - self->n_pos_args - self->n_kwonly_args, self->n_pos_args + self->n_kwonly_args);
// Check that all mandatory positional args are specified
while (d >= flat_args) {
if (*d-- == MP_OBJ_NULL) {
while (d < &code_state->state[n_state]) {
if (*d++ == MP_OBJ_NULL) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
"function missing required positional argument #%d", d - flat_args));
"function missing required positional argument #%d", &code_state->state[n_state] - d));
}
}
// Check that all mandatory keyword args are specified
// Fill in default kw args if we have them
for (int i = 0; i < self->n_kwonly_args; i++) {
if (flat_args[self->n_pos_args + i] == MP_OBJ_NULL) {
for (uint i = 0; i < self->n_kwonly_args; i++) {
if (code_state->state[n_state - 1 - self->n_pos_args - i] == MP_OBJ_NULL) {
mp_map_elem_t *elem = NULL;
if (self->has_def_kw_args) {
elem = mp_map_lookup(&((mp_obj_dict_t*)self->extra_args[self->n_def_args])->map, MP_OBJ_NEW_QSTR(self->args[self->n_pos_args + i]), MP_MAP_LOOKUP);
}
if (elem != NULL) {
flat_args[self->n_pos_args + i] = elem->value;
code_state->state[n_state - 1 - self->n_pos_args - i] = elem->value;
} else {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
"function missing required keyword argument '%s'", qstr_str(self->args[self->n_pos_args + i])));
......@@ -375,13 +400,6 @@ continue2:;
}
}
args = flat_args;
n_args = self->n_pos_args + self->n_kwonly_args;
if (self->takes_kw_args) {
extra_args[n_extra_args] = dict;
n_extra_args += 1;
}
} else {
// no keyword arguments given
if (self->n_kwonly_args != 0) {
......@@ -389,73 +407,28 @@ continue2:;
"function missing keyword-only argument"));
}
if (self->takes_kw_args) {
extra_args[n_extra_args] = mp_obj_new_dict(0);
n_extra_args += 1;
*var_pos_kw_args = mp_obj_new_dict(0);
}
}
mp_obj_dict_t *old_globals = mp_globals_get();
mp_globals_set(self->globals);
mp_obj_t result;
DEBUG_printf("Calling: args=%p, n_args=%d, extra_args=%p, n_extra_args=%d\n", args, n_args, extra_args, n_extra_args);
dump_args(args, n_args);
dump_args(extra_args, n_extra_args);
// At this point the args have all been processed and we are ready to
// execute the bytecode. But we must first build the execution context.
const byte *ip = self->bytecode;
// get code info size, and skip line number table
machine_uint_t code_info_size = ip[0] | (ip[1] << 8) | (ip[2] << 16) | (ip[3] << 24);
ip += code_info_size;
// bytecode prelude: state size and exception stack size; 16 bit uints
machine_uint_t n_state = ip[0] | (ip[1] << 8);
machine_uint_t n_exc_stack = ip[2] | (ip[3] << 8);
ip += 4;
// allocate state for locals and stack
#if VM_DETECT_STACK_OVERFLOW
n_state += 1;
#endif
int state_size = n_state * sizeof(mp_obj_t) + n_exc_stack * sizeof(mp_exc_stack_t);
mp_code_state *code_state;
if (state_size > VM_MAX_STATE_ON_STACK) {
code_state = m_new_obj_var(mp_code_state, byte, state_size);
} else {
code_state = alloca(sizeof(mp_code_state) + state_size);
}
code_state->code_info = self->bytecode;
code_state->sp = &code_state->state[0] - 1;
code_state->exc_sp = (mp_exc_stack_t*)(code_state->state + n_state) - 1;
code_state->n_state = n_state;
// init args
for (uint i = 0; i < n_args; i++) {
code_state->state[n_state - 1 - i] = args[i];
}
for (uint i = 0; i < n_extra_args; i++) {
code_state->state[n_state - 1 - n_args - i] = extra_args[i];
}
// set rest of state to MP_OBJ_NULL
for (uint i = 0; i < n_state - n_args - n_extra_args; i++) {
code_state->state[i] = MP_OBJ_NULL;
}
// bytecode prelude: initialise closed over variables
for (uint n_local = *ip++; n_local > 0; n_local--) {
uint local_num = *ip++;
code_state->state[n_state - 1 - local_num] = mp_obj_new_cell(code_state->state[n_state - 1 - local_num]);
}
// now that we skipped over the prelude, set the ip for the VM
code_state->ip = ip;
// execute the byte code
DEBUG_printf("Calling: n_pos_args=%d, n_kwonly_args=%d\n", self->n_pos_args, self->n_kwonly_args);
dump_args(code_state->state + n_state - self->n_pos_args - self->n_kwonly_args, self->n_pos_args + self->n_kwonly_args);
dump_args(code_state->state, n_state);
// execute the byte code with the correct globals context
mp_obj_dict_t *old_globals = mp_globals_get();
mp_globals_set(self->globals);
mp_vm_return_kind_t vm_return_kind = mp_execute_bytecode(code_state, MP_OBJ_NULL);
mp_globals_set(old_globals);
#if VM_DETECT_STACK_OVERFLOW
if (vm_return_kind == MP_VM_RETURN_NORMAL) {
......@@ -467,10 +440,10 @@ continue2:;
// We can't check the case when an exception is returned in state[n_state - 1]
// and there are no arguments, because in this case our detection slot may have
// been overwritten by the returned exception (which is allowed).
if (!(vm_return_kind == MP_VM_RETURN_EXCEPTION && n_args == 0 && n_extra_args == 0)) {
if (!(vm_return_kind == MP_VM_RETURN_EXCEPTION && self->n_pos_args + self->n_kwonly_args == 0)) {
// Just check to see that we have at least 1 null object left in the state.
bool overflow = true;
for (uint i = 0; i < n_state - n_args - n_extra_args; i++) {
for (uint i = 0; i < n_state - self->n_pos_args - self->n_kwonly_args; i++) {
if (code_state->state[i] == MP_OBJ_NULL) {
overflow = false;
break;
......@@ -483,6 +456,7 @@ continue2:;
}
#endif
mp_obj_t result;
switch (vm_return_kind) {
case MP_VM_RETURN_NORMAL:
// return value is in *sp
......@@ -507,8 +481,6 @@ continue2:;
m_del_var(mp_code_state, byte, state_size, code_state);
}
mp_globals_set(old_globals);
if (vm_return_kind == MP_VM_RETURN_NORMAL) {
return result;
} else { // MP_VM_RETURN_EXCEPTION
......@@ -538,12 +510,6 @@ mp_obj_t mp_obj_new_fun_bc(uint scope_flags, qstr *args, uint n_pos_args, uint n
if (def_kw_args != MP_OBJ_NULL) {
n_extra_args += 1;
}
if ((scope_flags & MP_SCOPE_FLAG_VARARGS) != 0) {
n_extra_args += 1;
}
if ((scope_flags & MP_SCOPE_FLAG_VARKEYWORDS) != 0) {
n_extra_args += 1;
}
mp_obj_fun_bc_t *o = m_new_obj_var(mp_obj_fun_bc_t, mp_obj_t, n_extra_args);
o->base.type = &mp_type_fun_bc;
o->globals = mp_globals_get();
......@@ -555,20 +521,11 @@ mp_obj_t mp_obj_new_fun_bc(uint scope_flags, qstr *args, uint n_pos_args, uint n
o->takes_var_args = (scope_flags & MP_SCOPE_FLAG_VARARGS) != 0;
o->takes_kw_args = (scope_flags & MP_SCOPE_FLAG_VARKEYWORDS) != 0;
o->bytecode = code;
mp_obj_t *extra_args = o->extra_args;
memset(extra_args, 0, n_extra_args * sizeof(mp_obj_t));
if (def_args != MP_OBJ_NULL) {
memcpy(extra_args, def_args->items, n_def_args * sizeof(mp_obj_t));
extra_args += n_def_args;
memcpy(o->extra_args, def_args->items, n_def_args * sizeof(mp_obj_t));
}
if (def_kw_args != MP_OBJ_NULL) {
*extra_args++ = def_kw_args;
}
if ((scope_flags & MP_SCOPE_FLAG_VARARGS) != 0) {
*extra_args++ = MP_OBJ_NULL;
}
if ((scope_flags & MP_SCOPE_FLAG_VARARGS) != 0) {
*extra_args = MP_OBJ_NULL;
o->extra_args[n_def_args] = def_kw_args;
}
return o;
}
......
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