micropython/py/bc.c

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2014 Damien P. George
* Copyright (c) 2014 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 <stdbool.h>
#include <string.h>
#include <assert.h>
#include "py/runtime.h"
#include "py/bc0.h"
#include "py/bc.h"
#if MICROPY_DEBUG_VERBOSE // print debugging info
#define DEBUG_PRINT (1)
#else // don't print debugging info
#define DEBUG_PRINT (0)
#define DEBUG_printf(...) (void)0
#endif
#if !MICROPY_PERSISTENT_CODE
mp_uint_t mp_decode_uint(const byte **ptr) {
mp_uint_t unum = 0;
byte val;
const byte *p = *ptr;
do {
val = *p++;
unum = (unum << 7) | (val & 0x7f);
} while ((val & 0x80) != 0);
*ptr = p;
return unum;
}
// This function is used to help reduce stack usage at the caller, for the case when
// the caller doesn't need to increase the ptr argument. If ptr is a local variable
// and the caller uses mp_decode_uint(&ptr) instead of this function, then the compiler
// must allocate a slot on the stack for ptr, and this slot cannot be reused for
// anything else in the function because the pointer may have been stored in a global
// and reused later in the function.
mp_uint_t mp_decode_uint_value(const byte *ptr) {
return mp_decode_uint(&ptr);
}
// This function is used to help reduce stack usage at the caller, for the case when
// the caller doesn't need the actual value and just wants to skip over it.
const byte *mp_decode_uint_skip(const byte *ptr) {
while ((*ptr++) & 0x80) {
}
return ptr;
}
#endif
STATIC NORETURN void fun_pos_args_mismatch(mp_obj_fun_bc_t *f, size_t expected, size_t given) {
#if MICROPY_ERROR_REPORTING <= MICROPY_ERROR_REPORTING_TERSE
// generic message, used also for other argument issues
(void)f;
(void)expected;
(void)given;
mp_arg_error_terse_mismatch();
#elif MICROPY_ERROR_REPORTING == MICROPY_ERROR_REPORTING_NORMAL
(void)f;
mp_raise_msg_varg(&mp_type_TypeError,
MP_ERROR_TEXT("function takes %d positional arguments but %d were given"), expected, given);
#elif MICROPY_ERROR_REPORTING == MICROPY_ERROR_REPORTING_DETAILED
mp_raise_msg_varg(&mp_type_TypeError,
MP_ERROR_TEXT("%q() takes %d positional arguments but %d were given"),
mp_obj_fun_get_name(MP_OBJ_FROM_PTR(f)), expected, given);
#endif
}
#if DEBUG_PRINT
STATIC void dump_args(const mp_obj_t *a, size_t sz) {
DEBUG_printf("%p: ", a);
for (size_t i = 0; i < sz; i++) {
DEBUG_printf("%p ", a[i]);
}
DEBUG_printf("\n");
}
#else
#define dump_args(...) (void)0
#endif
// On entry code_state should be allocated somewhere (stack/heap) and
// contain the following valid entries:
// - code_state->fun_bc should contain a pointer to the function object
// - code_state->ip should contain the offset in bytes from the pointer
// code_state->fun_bc->bytecode to the entry n_state (0 for bytecode, non-zero for native)
void mp_setup_code_state(mp_code_state_t *code_state, size_t n_args, size_t 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.
// get the function object that we want to set up (could be bytecode or native code)
mp_obj_fun_bc_t *self = code_state->fun_bc;
// ip comes in as an offset into bytecode, so turn it into a true pointer
code_state->ip = self->bytecode + (size_t)code_state->ip;
#if MICROPY_STACKLESS
code_state->prev = NULL;
#endif
#if MICROPY_PY_SYS_SETTRACE
code_state->prev_state = NULL;
code_state->frame = NULL;
#endif
// Get cached n_state (rather than decode it again)
size_t n_state = code_state->n_state;
// Decode prelude
size_t n_state_unused, n_exc_stack_unused, scope_flags, n_pos_args, n_kwonly_args, n_def_pos_args;
MP_BC_PRELUDE_SIG_DECODE_INTO(code_state->ip, n_state_unused, n_exc_stack_unused, scope_flags, n_pos_args, n_kwonly_args, n_def_pos_args);
(void)n_state_unused;
(void)n_exc_stack_unused;
code_state->sp = &code_state->state[0] - 1;
code_state->exc_sp_idx = 0;
// 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;
// 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 - n_pos_args - n_kwonly_args];
// check positional arguments
if (n_args > n_pos_args) {
// given more than enough arguments
if ((scope_flags & MP_SCOPE_FLAG_VARARGS) == 0) {
fun_pos_args_mismatch(self, n_pos_args, n_args);
}
// put extra arguments in varargs tuple
*var_pos_kw_args-- = mp_obj_new_tuple(n_args - n_pos_args, args + n_pos_args);
n_args = n_pos_args;
} else {
if ((scope_flags & MP_SCOPE_FLAG_VARARGS) != 0) {
DEBUG_printf("passing empty tuple as *args\n");
*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 && (scope_flags & MP_SCOPE_FLAG_DEFKWARGS) == 0) {
if (n_args >= (size_t)(n_pos_args - n_def_pos_args)) {
// given enough arguments, but may need to use some default arguments
for (size_t i = n_args; i < n_pos_args; i++) {
code_state->state[n_state - 1 - i] = self->extra_args[i - (n_pos_args - n_def_pos_args)];
}
} else {
fun_pos_args_mismatch(self, n_pos_args - n_def_pos_args, n_args);
}
}
}
// copy positional args into state
for (size_t i = 0; i < n_args; i++) {
code_state->state[n_state - 1 - i] = args[i];
}
// check keyword arguments
if (n_kw != 0 || (scope_flags & MP_SCOPE_FLAG_DEFKWARGS) != 0) {
DEBUG_printf("Initial args: ");
dump_args(code_state->state + n_state - n_pos_args - n_kwonly_args, n_pos_args + n_kwonly_args);
mp_obj_t dict = MP_OBJ_NULL;
if ((scope_flags & MP_SCOPE_FLAG_VARKEYWORDS) != 0) {
dict = mp_obj_new_dict(n_kw); // TODO: better go conservative with 0?
*var_pos_kw_args = dict;
}
// get pointer to arg_names array
const mp_obj_t *arg_names = (const mp_obj_t *)self->const_table;
for (size_t i = 0; i < n_kw; i++) {
// the keys in kwargs are expected to be qstr objects
mp_obj_t wanted_arg_name = kwargs[2 * i];
for (size_t j = 0; j < n_pos_args + n_kwonly_args; j++) {
if (wanted_arg_name == arg_names[j]) {
if (code_state->state[n_state - 1 - j] != MP_OBJ_NULL) {
mp_raise_msg_varg(&mp_type_TypeError,
MP_ERROR_TEXT("function got multiple values for argument '%q'"), MP_OBJ_QSTR_VALUE(wanted_arg_name));
}
code_state->state[n_state - 1 - j] = kwargs[2 * i + 1];
goto continue2;
}
}
// Didn't find name match with positional args
if ((scope_flags & MP_SCOPE_FLAG_VARKEYWORDS) == 0) {
#if MICROPY_ERROR_REPORTING <= MICROPY_ERROR_REPORTING_TERSE
mp_raise_TypeError(MP_ERROR_TEXT("unexpected keyword argument"));
#else
mp_raise_msg_varg(&mp_type_TypeError,
MP_ERROR_TEXT("unexpected keyword argument '%q'"), MP_OBJ_QSTR_VALUE(wanted_arg_name));
#endif
}
mp_obj_dict_store(dict, kwargs[2 * i], kwargs[2 * i + 1]);
continue2:;
}
DEBUG_printf("Args with kws flattened: ");
dump_args(code_state->state + n_state - n_pos_args - n_kwonly_args, n_pos_args + n_kwonly_args);
// fill in defaults for positional args
mp_obj_t *d = &code_state->state[n_state - n_pos_args];
mp_obj_t *s = &self->extra_args[n_def_pos_args - 1];
for (size_t i = n_def_pos_args; i > 0; i--, d++, s--) {
if (*d == MP_OBJ_NULL) {
*d = *s;
}
}
DEBUG_printf("Args after filling default positional: ");
dump_args(code_state->state + n_state - n_pos_args - n_kwonly_args, n_pos_args + n_kwonly_args);
// Check that all mandatory positional args are specified
while (d < &code_state->state[n_state]) {
if (*d++ == MP_OBJ_NULL) {
mp_raise_msg_varg(&mp_type_TypeError,
MP_ERROR_TEXT("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 (size_t i = 0; i < n_kwonly_args; i++) {
if (code_state->state[n_state - 1 - n_pos_args - i] == MP_OBJ_NULL) {
mp_map_elem_t *elem = NULL;
if ((scope_flags & MP_SCOPE_FLAG_DEFKWARGS) != 0) {
elem = mp_map_lookup(&((mp_obj_dict_t *)MP_OBJ_TO_PTR(self->extra_args[n_def_pos_args]))->map, arg_names[n_pos_args + i], MP_MAP_LOOKUP);
}
if (elem != NULL) {
code_state->state[n_state - 1 - n_pos_args - i] = elem->value;
} else {
mp_raise_msg_varg(&mp_type_TypeError,
MP_ERROR_TEXT("function missing required keyword argument '%q'"), MP_OBJ_QSTR_VALUE(arg_names[n_pos_args + i]));
}
}
}
} else {
// no keyword arguments given
if (n_kwonly_args != 0) {
mp_raise_TypeError(MP_ERROR_TEXT("function missing keyword-only argument"));
}
if ((scope_flags & MP_SCOPE_FLAG_VARKEYWORDS) != 0) {
*var_pos_kw_args = mp_obj_new_dict(0);
}
}
// read the size part of the prelude
const byte *ip = code_state->ip;
MP_BC_PRELUDE_SIZE_DECODE(ip);
// jump over code info (source file and line-number mapping)
ip += n_info;
// bytecode prelude: initialise closed over variables
for (; n_cell; --n_cell) {
size_t local_num = *ip++;
code_state->state[n_state - 1 - local_num] =
mp_obj_new_cell(code_state->state[n_state - 1 - local_num]);
}
#if !MICROPY_PERSISTENT_CODE
// so bytecode is aligned
ip = MP_ALIGN(ip, sizeof(mp_uint_t));
#endif
// now that we skipped over the prelude, set the ip for the VM
code_state->ip = ip;
DEBUG_printf("Calling: n_pos_args=%d, n_kwonly_args=%d\n", n_pos_args, n_kwonly_args);
dump_args(code_state->state + n_state - n_pos_args - n_kwonly_args, n_pos_args + n_kwonly_args);
dump_args(code_state->state, n_state);
}
#if MICROPY_PERSISTENT_CODE_LOAD || MICROPY_PERSISTENT_CODE_SAVE
// The following table encodes the number of bytes that a specific opcode
// takes up. Some opcodes have an extra byte, defined by MP_BC_MASK_EXTRA_BYTE.
// There are 4 special opcodes that have an extra byte only when
// MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE is enabled (and they take a qstr):
// MP_BC_LOAD_NAME
// MP_BC_LOAD_GLOBAL
// MP_BC_LOAD_ATTR
// MP_BC_STORE_ATTR
uint mp_opcode_format(const byte *ip, size_t *opcode_size, bool count_var_uint) {
uint f = MP_BC_FORMAT(*ip);
const byte *ip_start = ip;
if (f == MP_BC_FORMAT_QSTR) {
if (MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE_DYNAMIC) {
if (*ip == MP_BC_LOAD_NAME
|| *ip == MP_BC_LOAD_GLOBAL
|| *ip == MP_BC_LOAD_ATTR
|| *ip == MP_BC_STORE_ATTR) {
ip += 1;
}
}
ip += 3;
} else {
int extra_byte = (*ip & MP_BC_MASK_EXTRA_BYTE) == 0;
ip += 1;
if (f == MP_BC_FORMAT_VAR_UINT) {
if (count_var_uint) {
while ((*ip++ & 0x80) != 0) {
}
}
} else if (f == MP_BC_FORMAT_OFFSET) {
ip += 2;
}
ip += extra_byte;
}
*opcode_size = ip - ip_start;
return f;
}
#endif // MICROPY_PERSISTENT_CODE_LOAD || MICROPY_PERSISTENT_CODE_SAVE