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circuitpython/py/vm.c
Damien George 25c84643b6 py: Fix break from within a for loop. 
Needed to pop the iterator object when breaking out of a for loop.  Need
also to be careful to unwind exception handler before popping iterator.

Addresses issue #635.
2014-05-30 15:20:41 +01:00

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/*
* This file is part of the Micro Python project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 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 <stdio.h>
#include <string.h>
#include <assert.h>
#include "mpconfig.h"
#include "nlr.h"
#include "misc.h"
#include "qstr.h"
#include "obj.h"
#include "emitglue.h"
#include "runtime.h"
#include "bc0.h"
#include "bc.h"
#include "objgenerator.h"
// With these macros you can tune the maximum number of state slots
// that will be allocated on the stack. Any function that needs more
// than this will use the heap.
#define VM_MAX_STATE_ON_STACK (10)
#define VM_MAX_EXC_STATE_ON_STACK (4)
#define DETECT_VM_STACK_OVERFLOW (0)
#if 0
#define TRACE(ip) mp_bytecode_print2(ip, 1);
#else
#define TRACE(ip)
#endif
// Value stack grows up (this makes it incompatible with native C stack, but
// makes sure that arguments to functions are in natural order arg1..argN
// (Python semantics mandates left-to-right evaluation order, including for
// function arguments). Stack pointer is pre-incremented and points at the
// top element.
// Exception stack also grows up, top element is also pointed at.
// Exception stack unwind reasons (WHY_* in CPython-speak)
// TODO perhaps compress this to RETURN=0, JUMP>0, with number of unwinds
// left to do encoded in the JUMP number
typedef enum {
UNWIND_RETURN = 1,
UNWIND_JUMP,
} mp_unwind_reason_t;
#define DECODE_UINT do { \
unum = 0; \
do { \
unum = (unum << 7) + (*ip & 0x7f); \
} while ((*ip++ & 0x80) != 0); \
} while (0)
#define DECODE_ULABEL do { unum = (ip[0] | (ip[1] << 8)); ip += 2; } while (0)
#define DECODE_SLABEL do { unum = (ip[0] | (ip[1] << 8)) - 0x8000; ip += 2; } while (0)
#define DECODE_QSTR qstr qst = 0; \
do { \
qst = (qst << 7) + (*ip & 0x7f); \
} while ((*ip++ & 0x80) != 0)
#define DECODE_PTR do { \
ip = (byte*)(((machine_uint_t)ip + sizeof(machine_uint_t) - 1) & (~(sizeof(machine_uint_t) - 1))); /* align ip */ \
unum = *(machine_uint_t*)ip; \
ip += sizeof(machine_uint_t); \
} while (0)
#define PUSH(val) *++sp = (val)
#define POP() (*sp--)
#define TOP() (*sp)
#define SET_TOP(val) *sp = (val)
#define PUSH_EXC_BLOCK() \
DECODE_ULABEL; /* except labels are always forward */ \
++exc_sp; \
exc_sp->opcode = *save_ip; \
exc_sp->handler = ip + unum; \
exc_sp->val_sp = MP_TAGPTR_MAKE(sp, currently_in_except_block); \
exc_sp->prev_exc = MP_OBJ_NULL; \
currently_in_except_block = 0; /* in a try block now */
#define POP_EXC_BLOCK() \
currently_in_except_block = MP_TAGPTR_TAG(exc_sp->val_sp); /* restore previous state */ \
exc_sp--; /* pop back to previous exception handler */
mp_vm_return_kind_t mp_execute_bytecode(const byte *code, const mp_obj_t *args, uint n_args, const mp_obj_t *args2, uint n_args2, mp_obj_t *ret) {
const byte *ip = code;
// 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
mp_obj_t temp_state[VM_MAX_STATE_ON_STACK];
mp_obj_t *state = &temp_state[0];
#if DETECT_VM_STACK_OVERFLOW
n_state += 1;
#endif
if (n_state > VM_MAX_STATE_ON_STACK) {
state = m_new(mp_obj_t, n_state);
}
mp_obj_t *sp = &state[0] - 1;
// allocate state for exceptions
mp_exc_stack_t exc_state[VM_MAX_EXC_STATE_ON_STACK];
mp_exc_stack_t *exc_stack = &exc_state[0];
if (n_exc_stack > VM_MAX_EXC_STATE_ON_STACK) {
exc_stack = m_new(mp_exc_stack_t, n_exc_stack);
}
mp_exc_stack_t *exc_sp = &exc_stack[0] - 1;
// init args
for (uint i = 0; i < n_args; i++) {
state[n_state - 1 - i] = args[i];
}
for (uint i = 0; i < n_args2; i++) {
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++) {
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++;
state[n_state - 1 - local_num] = mp_obj_new_cell(state[n_state - 1 - local_num]);
}
// execute the byte code
mp_vm_return_kind_t vm_return_kind = mp_execute_bytecode2(code, &ip, &state[n_state - 1], &sp, exc_stack, &exc_sp, MP_OBJ_NULL);
#if DETECT_VM_STACK_OVERFLOW
// 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_args2 == 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_args2; i++) {
if (state[i] == MP_OBJ_NULL) {
overflow = false;
break;
}
}
if (overflow) {
printf("VM stack overflow state=%p n_state+1=%u\n", state, n_state);
assert(0);
}
}
#endif
mp_vm_return_kind_t ret_kind;
switch (vm_return_kind) {
case MP_VM_RETURN_NORMAL:
// return value is in *sp
*ret = *sp;
ret_kind = MP_VM_RETURN_NORMAL;
break;
case MP_VM_RETURN_EXCEPTION:
// return value is in state[n_state - 1]
*ret = state[n_state - 1];
ret_kind = MP_VM_RETURN_EXCEPTION;
break;
case MP_VM_RETURN_YIELD: // byte-code shouldn't yield
default:
assert(0);
*ret = mp_const_none;
ret_kind = MP_VM_RETURN_NORMAL;
}
// free the state if it was allocated on the heap
if (n_state > VM_MAX_STATE_ON_STACK) {
m_free(state, n_state);
}
// free the exception state if it was allocated on the heap
if (n_exc_stack > VM_MAX_EXC_STATE_ON_STACK) {
m_free(exc_stack, n_exc_stack);
}
return ret_kind;
}
// fastn has items in reverse order (fastn[0] is local[0], fastn[-1] is local[1], etc)
// sp points to bottom of stack which grows up
// returns:
// MP_VM_RETURN_NORMAL, sp valid, return value in *sp
// MP_VM_RETURN_YIELD, ip, sp valid, yielded value in *sp
// MP_VM_RETURN_EXCEPTION, exception in fastn[0]
mp_vm_return_kind_t mp_execute_bytecode2(const byte *code_info, const byte **ip_in_out,
mp_obj_t *fastn, mp_obj_t **sp_in_out,
mp_exc_stack_t *exc_stack, mp_exc_stack_t **exc_sp_in_out,
volatile mp_obj_t inject_exc) {
#if MICROPY_OPT_COMPUTED_GOTO
#include "vmentrytable.h"
#define DISPATCH() do { \
TRACE(ip); \
save_ip = ip; \
goto *entry_table[*ip++]; \
} while(0)
#define ENTRY(op) entry_##op
#define ENTRY_DEFAULT entry_default
#else
#define DISPATCH() break
#define ENTRY(op) case op
#define ENTRY_DEFAULT default
#endif
// nlr_raise needs to be implemented as a goto, so that the C compiler's flow analyser
// sees that it's possible for us to jump from the dispatch loop to the exception
// handler. Without this, the code may have a different stack layout in the dispatch
// loop and the exception handler, leading to very obscure bugs.
#define RAISE(o) do { nlr_pop(); nlr.ret_val = o; goto exception_handler; } while(0)
// variables that are visible to the exception handler (declared volatile)
volatile bool currently_in_except_block = MP_TAGPTR_TAG(*exc_sp_in_out); // 0 or 1, to detect nested exceptions
mp_exc_stack_t *volatile exc_sp = MP_TAGPTR_PTR(*exc_sp_in_out); // stack grows up, exc_sp points to top of stack
const byte *volatile save_ip = *ip_in_out; // 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)
mp_obj_t *volatile save_sp = *sp_in_out; // this is so we can access sp in the exception handler when needed
// outer exception handling loop
for (;;) {
nlr_buf_t nlr;
outer_dispatch_loop:
if (nlr_push(&nlr) == 0) {
// local variables that are not visible to the exception handler
const byte *ip = *ip_in_out;
mp_obj_t *sp = *sp_in_out;
machine_uint_t unum;
mp_obj_t obj_shared;
// 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.
// Injecting exc into yield from generator is a special case,
// handled by MP_BC_YIELD_FROM itself
if (inject_exc != MP_OBJ_NULL && *ip != MP_BC_YIELD_FROM) {
mp_obj_t exc = inject_exc;
inject_exc = MP_OBJ_NULL;
exc = mp_make_raise_obj(exc);
RAISE(exc);
}
// loop to execute byte code
for (;;) {
dispatch_loop:
#if MICROPY_OPT_COMPUTED_GOTO
DISPATCH();
#else
TRACE(ip);
save_ip = ip;
switch (*ip++) {
#endif
ENTRY(MP_BC_LOAD_CONST_FALSE):
PUSH(mp_const_false);
DISPATCH();
ENTRY(MP_BC_LOAD_CONST_NONE):
PUSH(mp_const_none);
DISPATCH();
ENTRY(MP_BC_LOAD_CONST_TRUE):
PUSH(mp_const_true);
DISPATCH();
ENTRY(MP_BC_LOAD_CONST_ELLIPSIS):
PUSH((mp_obj_t)&mp_const_ellipsis_obj);
DISPATCH();
ENTRY(MP_BC_LOAD_CONST_SMALL_INT): {
machine_int_t num = 0;
if ((ip[0] & 0x40) != 0) {
// Number is negative
num--;
}
do {
num = (num << 7) | (*ip & 0x7f);
} while ((*ip++ & 0x80) != 0);
PUSH(MP_OBJ_NEW_SMALL_INT(num));
DISPATCH();
}
ENTRY(MP_BC_LOAD_CONST_INT): {
DECODE_QSTR;
PUSH(mp_load_const_int(qst));
DISPATCH();
}
ENTRY(MP_BC_LOAD_CONST_DEC): {
DECODE_QSTR;
PUSH(mp_load_const_dec(qst));
DISPATCH();
}
ENTRY(MP_BC_LOAD_CONST_BYTES): {
DECODE_QSTR;
PUSH(mp_load_const_bytes(qst));
DISPATCH();
}
ENTRY(MP_BC_LOAD_CONST_STRING): {
DECODE_QSTR;
PUSH(mp_load_const_str(qst));
DISPATCH();
}
ENTRY(MP_BC_LOAD_NULL):
PUSH(MP_OBJ_NULL);
DISPATCH();
ENTRY(MP_BC_LOAD_FAST_0):
obj_shared = fastn[0];
goto load_check;
ENTRY(MP_BC_LOAD_FAST_1):
obj_shared = fastn[-1];
goto load_check;
ENTRY(MP_BC_LOAD_FAST_2):
obj_shared = fastn[-2];
goto load_check;
ENTRY(MP_BC_LOAD_FAST_N):
DECODE_UINT;
obj_shared = fastn[-unum];
load_check:
if (obj_shared == MP_OBJ_NULL) {
local_name_error: {
mp_obj_t obj = mp_obj_new_exception_msg(&mp_type_NameError, "local variable referenced before assignment");
RAISE(obj);
}
}
PUSH(obj_shared);
DISPATCH();
ENTRY(MP_BC_LOAD_DEREF):
DECODE_UINT;
obj_shared = mp_obj_cell_get(fastn[-unum]);
goto load_check;
ENTRY(MP_BC_LOAD_NAME): {
DECODE_QSTR;
PUSH(mp_load_name(qst));
DISPATCH();
}
ENTRY(MP_BC_LOAD_GLOBAL): {
DECODE_QSTR;
PUSH(mp_load_global(qst));
DISPATCH();
}
ENTRY(MP_BC_LOAD_ATTR): {
DECODE_QSTR;
SET_TOP(mp_load_attr(TOP(), qst));
DISPATCH();
}
ENTRY(MP_BC_LOAD_METHOD): {
DECODE_QSTR;
mp_load_method(*sp, qst, sp);
sp += 1;
DISPATCH();
}
ENTRY(MP_BC_LOAD_BUILD_CLASS):
PUSH(mp_load_build_class());
DISPATCH();
ENTRY(MP_BC_LOAD_SUBSCR): {
mp_obj_t index = POP();
SET_TOP(mp_obj_subscr(TOP(), index, MP_OBJ_SENTINEL));
DISPATCH();
}
ENTRY(MP_BC_STORE_FAST_0):
fastn[0] = POP();
DISPATCH();
ENTRY(MP_BC_STORE_FAST_1):
fastn[-1] = POP();
DISPATCH();
ENTRY(MP_BC_STORE_FAST_2):
fastn[-2] = POP();
DISPATCH();
ENTRY(MP_BC_STORE_FAST_N):
DECODE_UINT;
fastn[-unum] = POP();
DISPATCH();
ENTRY(MP_BC_STORE_DEREF):
DECODE_UINT;
mp_obj_cell_set(fastn[-unum], POP());
DISPATCH();
ENTRY(MP_BC_STORE_NAME): {
DECODE_QSTR;
mp_store_name(qst, POP());
DISPATCH();
}
ENTRY(MP_BC_STORE_GLOBAL): {
DECODE_QSTR;
mp_store_global(qst, POP());
DISPATCH();
}
ENTRY(MP_BC_STORE_ATTR): {
DECODE_QSTR;
mp_store_attr(sp[0], qst, sp[-1]);
sp -= 2;
DISPATCH();
}
ENTRY(MP_BC_STORE_SUBSCR):
mp_obj_subscr(sp[-1], sp[0], sp[-2]);
sp -= 3;
DISPATCH();
ENTRY(MP_BC_DELETE_FAST):
DECODE_UINT;
if (fastn[-unum] == MP_OBJ_NULL) {
goto local_name_error;
}
fastn[-unum] = MP_OBJ_NULL;
DISPATCH();
ENTRY(MP_BC_DELETE_DEREF):
DECODE_UINT;
if (mp_obj_cell_get(fastn[-unum]) == MP_OBJ_NULL) {
goto local_name_error;
}
mp_obj_cell_set(fastn[-unum], MP_OBJ_NULL);
DISPATCH();
ENTRY(MP_BC_DELETE_NAME): {
DECODE_QSTR;
mp_delete_name(qst);
DISPATCH();
}
ENTRY(MP_BC_DELETE_GLOBAL): {
DECODE_QSTR;
mp_delete_global(qst);
DISPATCH();
}
ENTRY(MP_BC_DUP_TOP): {
mp_obj_t top = TOP();
PUSH(top);
DISPATCH();
}
ENTRY(MP_BC_DUP_TOP_TWO):
sp += 2;
sp[0] = sp[-2];
sp[-1] = sp[-3];
DISPATCH();
ENTRY(MP_BC_POP_TOP):
sp -= 1;
DISPATCH();
ENTRY(MP_BC_ROT_TWO): {
mp_obj_t top = sp[0];
sp[0] = sp[-1];
sp[-1] = top;
DISPATCH();
}
ENTRY(MP_BC_ROT_THREE): {
mp_obj_t top = sp[0];
sp[0] = sp[-1];
sp[-1] = sp[-2];
sp[-2] = top;
DISPATCH();
}
ENTRY(MP_BC_JUMP):
DECODE_SLABEL;
ip += unum;
DISPATCH();
ENTRY(MP_BC_POP_JUMP_IF_TRUE):
DECODE_SLABEL;
if (mp_obj_is_true(POP())) {
ip += unum;
}
DISPATCH();
ENTRY(MP_BC_POP_JUMP_IF_FALSE):
DECODE_SLABEL;
if (!mp_obj_is_true(POP())) {
ip += unum;
}
DISPATCH();
ENTRY(MP_BC_JUMP_IF_TRUE_OR_POP):
DECODE_SLABEL;
if (mp_obj_is_true(TOP())) {
ip += unum;
} else {
sp--;
}
DISPATCH();
ENTRY(MP_BC_JUMP_IF_FALSE_OR_POP):
DECODE_SLABEL;
if (mp_obj_is_true(TOP())) {
sp--;
} else {
ip += unum;
}
DISPATCH();
ENTRY(MP_BC_SETUP_WITH): {
mp_obj_t obj = TOP();
SET_TOP(mp_load_attr(obj, MP_QSTR___exit__));
mp_load_method(obj, MP_QSTR___enter__, sp + 1);
mp_obj_t ret = mp_call_method_n_kw(0, 0, sp + 1);
PUSH_EXC_BLOCK();
PUSH(ret);
DISPATCH();
}
ENTRY(MP_BC_WITH_CLEANUP): {
// Arriving here, there's "exception control block" on top of stack,
// and __exit__ bound method underneath it. Bytecode calls __exit__,
// and "deletes" it off stack, shifting "exception control block"
// to its place.
static const mp_obj_t no_exc[] = {mp_const_none, mp_const_none, mp_const_none};
if (TOP() == mp_const_none) {
sp--;
mp_obj_t obj = TOP();
SET_TOP(mp_const_none);
mp_call_function_n_kw(obj, 3, 0, no_exc);
} else if (MP_OBJ_IS_SMALL_INT(TOP())) {
mp_obj_t cause = POP();
switch (MP_OBJ_SMALL_INT_VALUE(cause)) {
case UNWIND_RETURN: {
mp_obj_t retval = POP();
mp_call_function_n_kw(TOP(), 3, 0, no_exc);
SET_TOP(retval);
PUSH(cause);
break;
}
case UNWIND_JUMP: {
mp_call_function_n_kw(sp[-2], 3, 0, no_exc);
// Pop __exit__ boundmethod at sp[-2]
sp[-2] = sp[-1];
sp[-1] = sp[0];
SET_TOP(cause);
break;
}
default:
assert(0);
}
} else if (mp_obj_is_exception_type(TOP())) {
mp_obj_t args[3] = {sp[0], sp[-1], sp[-2]};
mp_obj_t ret_value = mp_call_function_n_kw(sp[-3], 3, 0, args);
// Pop __exit__ boundmethod at sp[-3]
// TODO: Once semantics is proven, optimize for case when ret_value == True
sp[-3] = sp[-2];
sp[-2] = sp[-1];
sp[-1] = sp[0];
sp--;
if (mp_obj_is_true(ret_value)) {
// This is what CPython does
//PUSH(MP_OBJ_NEW_SMALL_INT(UNWIND_SILENCED));
// But what we need to do is - pop exception from value stack...
sp -= 3;
// ... pop "with" exception handler, and signal END_FINALLY
// to just execute finally handler normally (by pushing None
// on value stack)
assert(exc_sp >= exc_stack);
assert(exc_sp->opcode == MP_BC_SETUP_WITH);
POP_EXC_BLOCK();
PUSH(mp_const_none);
}
} else {
assert(0);
}
DISPATCH();
}
ENTRY(MP_BC_UNWIND_JUMP):
DECODE_SLABEL;
PUSH((void*)(ip + unum)); // push destination ip for jump
PUSH((void*)(machine_uint_t)(*ip)); // push number of exception handlers to unwind (0x80 bit set if we also need to pop stack)
unwind_jump:
unum = (machine_uint_t)POP(); // get number of exception handlers to unwind
while ((unum & 0x7f) > 0) {
unum -= 1;
assert(exc_sp >= exc_stack);
if (exc_sp->opcode == MP_BC_SETUP_FINALLY || exc_sp->opcode == MP_BC_SETUP_WITH) {
// We're going to run "finally" code as a coroutine
// (not calling it recursively). Set up a sentinel
// on a stack so it can return back to us when it is
// done (when END_FINALLY reached).
PUSH((void*)unum); // push number of exception handlers left to unwind
PUSH(MP_OBJ_NEW_SMALL_INT(UNWIND_JUMP)); // push sentinel
ip = exc_sp->handler; // get exception handler byte code address
exc_sp--; // pop exception handler
goto dispatch_loop; // run the exception handler
}
exc_sp--;
}
ip = (const byte*)POP(); // pop destination ip for jump
if (unum != 0) {
sp--;
}
DISPATCH();
// matched against: POP_BLOCK or POP_EXCEPT (anything else?)
ENTRY(MP_BC_SETUP_EXCEPT):
ENTRY(MP_BC_SETUP_FINALLY):
PUSH_EXC_BLOCK();
DISPATCH();
ENTRY(MP_BC_END_FINALLY):
// not fully implemented
// if TOS is an exception, reraises the exception (3 values on TOS)
// if TOS is None, just pops it and continues
// if TOS is an integer, does something else
// else error
if (mp_obj_is_exception_type(TOP())) {
RAISE(sp[-1]);
}
if (TOP() == mp_const_none) {
sp--;
} else if (MP_OBJ_IS_SMALL_INT(TOP())) {
// We finished "finally" coroutine and now dispatch back
// to our caller, based on TOS value
mp_unwind_reason_t reason = MP_OBJ_SMALL_INT_VALUE(POP());
switch (reason) {
case UNWIND_RETURN:
goto unwind_return;
case UNWIND_JUMP:
goto unwind_jump;
}
assert(0);
} else {
assert(0);
}
DISPATCH();
ENTRY(MP_BC_GET_ITER):
SET_TOP(mp_getiter(TOP()));
DISPATCH();
ENTRY(MP_BC_FOR_ITER): {
DECODE_ULABEL; // the jump offset if iteration finishes; for labels are always forward
save_sp = sp;
assert(TOP());
mp_obj_t value = mp_iternext_allow_raise(TOP());
if (value == MP_OBJ_STOP_ITERATION) {
--sp; // pop the exhausted iterator
ip += unum; // jump to after for-block
} else {
PUSH(value); // push the next iteration value
}
DISPATCH();
}
// matched against: SETUP_EXCEPT, SETUP_FINALLY, SETUP_WITH
ENTRY(MP_BC_POP_BLOCK):
// we are exiting an exception handler, so pop the last one of the exception-stack
assert(exc_sp >= exc_stack);
POP_EXC_BLOCK();
DISPATCH();
// matched against: SETUP_EXCEPT
ENTRY(MP_BC_POP_EXCEPT):
// TODO need to work out how blocks work etc
// pops block, checks it's an exception block, and restores the stack, saving the 3 exception values to local threadstate
assert(exc_sp >= exc_stack);
assert(currently_in_except_block);
//sp = (mp_obj_t*)(*exc_sp--);
//exc_sp--; // discard ip
POP_EXC_BLOCK();
//sp -= 3; // pop 3 exception values
DISPATCH();
ENTRY(MP_BC_NOT):
if (TOP() == mp_const_true) {
SET_TOP(mp_const_false);
} else {
SET_TOP(mp_const_true);
}
DISPATCH();
ENTRY(MP_BC_UNARY_OP):
unum = *ip++;
SET_TOP(mp_unary_op(unum, TOP()));
DISPATCH();
ENTRY(MP_BC_BINARY_OP): {
unum = *ip++;
mp_obj_t rhs = POP();
mp_obj_t lhs = TOP();
SET_TOP(mp_binary_op(unum, lhs, rhs));
DISPATCH();
}
ENTRY(MP_BC_BUILD_TUPLE):
DECODE_UINT;
sp -= unum - 1;
SET_TOP(mp_obj_new_tuple(unum, sp));
DISPATCH();
ENTRY(MP_BC_BUILD_LIST):
DECODE_UINT;
sp -= unum - 1;
SET_TOP(mp_obj_new_list(unum, sp));
DISPATCH();
ENTRY(MP_BC_LIST_APPEND):
DECODE_UINT;
// I think it's guaranteed by the compiler that sp[unum] is a list
mp_obj_list_append(sp[-unum], sp[0]);
sp--;
DISPATCH();
ENTRY(MP_BC_BUILD_MAP):
DECODE_UINT;
PUSH(mp_obj_new_dict(unum));
DISPATCH();
ENTRY(MP_BC_STORE_MAP):
sp -= 2;
mp_obj_dict_store(sp[0], sp[2], sp[1]);
DISPATCH();
ENTRY(MP_BC_MAP_ADD):
DECODE_UINT;
// I think it's guaranteed by the compiler that sp[-unum - 1] is a map
mp_obj_dict_store(sp[-unum - 1], sp[0], sp[-1]);
sp -= 2;
DISPATCH();
ENTRY(MP_BC_BUILD_SET):
DECODE_UINT;
sp -= unum - 1;
SET_TOP(mp_obj_new_set(unum, sp));
DISPATCH();
ENTRY(MP_BC_SET_ADD):
DECODE_UINT;
// I think it's guaranteed by the compiler that sp[-unum] is a set
mp_obj_set_store(sp[-unum], sp[0]);
sp--;
DISPATCH();
#if MICROPY_PY_SLICE
ENTRY(MP_BC_BUILD_SLICE):
DECODE_UINT;
if (unum == 2) {
mp_obj_t stop = POP();
mp_obj_t start = TOP();
SET_TOP(mp_obj_new_slice(start, stop, mp_const_none));
} else {
mp_obj_t step = POP();
mp_obj_t stop = POP();
mp_obj_t start = TOP();
SET_TOP(mp_obj_new_slice(start, stop, step));
}
DISPATCH();
#endif
ENTRY(MP_BC_UNPACK_SEQUENCE):
DECODE_UINT;
mp_unpack_sequence(sp[0], unum, sp);
sp += unum - 1;
DISPATCH();
ENTRY(MP_BC_UNPACK_EX):
DECODE_UINT;
mp_unpack_ex(sp[0], unum, sp);
sp += (unum & 0xff) + ((unum >> 8) & 0xff);
DISPATCH();
ENTRY(MP_BC_MAKE_FUNCTION):
DECODE_PTR;
PUSH(mp_make_function_from_raw_code((mp_raw_code_t*)unum, MP_OBJ_NULL, MP_OBJ_NULL));
DISPATCH();
ENTRY(MP_BC_MAKE_FUNCTION_DEFARGS): {
DECODE_PTR;
// Stack layout: def_tuple def_dict <- TOS
mp_obj_t def_dict = POP();
SET_TOP(mp_make_function_from_raw_code((mp_raw_code_t*)unum, TOP(), def_dict));
DISPATCH();
}
ENTRY(MP_BC_MAKE_CLOSURE): {
DECODE_PTR;
machine_uint_t n_closed_over = *ip++;
// Stack layout: closed_overs <- TOS
sp -= n_closed_over - 1;
SET_TOP(mp_make_closure_from_raw_code((mp_raw_code_t*)unum, n_closed_over, sp));
DISPATCH();
}
ENTRY(MP_BC_MAKE_CLOSURE_DEFARGS): {
DECODE_PTR;
machine_uint_t n_closed_over = *ip++;
// Stack layout: def_tuple def_dict closed_overs <- TOS
sp -= 2 + n_closed_over - 1;
SET_TOP(mp_make_closure_from_raw_code((mp_raw_code_t*)unum, 0x100 | n_closed_over, sp));
DISPATCH();
}
ENTRY(MP_BC_CALL_FUNCTION):
DECODE_UINT;
// unum & 0xff == n_positional
// (unum >> 8) & 0xff == n_keyword
sp -= (unum & 0xff) + ((unum >> 7) & 0x1fe);
SET_TOP(mp_call_function_n_kw(*sp, unum & 0xff, (unum >> 8) & 0xff, sp + 1));
DISPATCH();
ENTRY(MP_BC_CALL_FUNCTION_VAR_KW):
DECODE_UINT;
// unum & 0xff == n_positional
// (unum >> 8) & 0xff == n_keyword
// We have folowing stack layout here:
// fun arg0 arg1 ... kw0 val0 kw1 val1 ... seq dict <- TOS
sp -= (unum & 0xff) + ((unum >> 7) & 0x1fe) + 2;
SET_TOP(mp_call_method_n_kw_var(false, unum, sp));
DISPATCH();
ENTRY(MP_BC_CALL_METHOD):
DECODE_UINT;
// unum & 0xff == n_positional
// (unum >> 8) & 0xff == n_keyword
sp -= (unum & 0xff) + ((unum >> 7) & 0x1fe) + 1;
SET_TOP(mp_call_method_n_kw(unum & 0xff, (unum >> 8) & 0xff, sp));
DISPATCH();
ENTRY(MP_BC_CALL_METHOD_VAR_KW):
DECODE_UINT;
// unum & 0xff == n_positional
// (unum >> 8) & 0xff == n_keyword
// We have folowing stack layout here:
// fun self arg0 arg1 ... kw0 val0 kw1 val1 ... seq dict <- TOS
sp -= (unum & 0xff) + ((unum >> 7) & 0x1fe) + 3;
SET_TOP(mp_call_method_n_kw_var(true, unum, sp));
DISPATCH();
ENTRY(MP_BC_RETURN_VALUE):
unwind_return:
while (exc_sp >= exc_stack) {
if (exc_sp->opcode == MP_BC_SETUP_FINALLY || exc_sp->opcode == MP_BC_SETUP_WITH) {
// We're going to run "finally" code as a coroutine
// (not calling it recursively). Set up a sentinel
// on a stack so it can return back to us when it is
// done (when END_FINALLY reached).
PUSH(MP_OBJ_NEW_SMALL_INT(UNWIND_RETURN));
ip = exc_sp->handler;
// We don't need to do anything with sp, finally is just
// syntactic sugar for sequential execution??
// sp =
exc_sp--;
goto dispatch_loop;
}
exc_sp--;
}
nlr_pop();
*sp_in_out = sp;
assert(exc_sp == exc_stack - 1);
return MP_VM_RETURN_NORMAL;
ENTRY(MP_BC_RAISE_VARARGS): {
unum = *ip++;
mp_obj_t obj;
assert(unum <= 1);
if (unum == 0) {
// search for the inner-most previous exception, to reraise it
obj = MP_OBJ_NULL;
for (mp_exc_stack_t *e = exc_sp; e >= exc_stack; e--) {
if (e->prev_exc != MP_OBJ_NULL) {
obj = e->prev_exc;
break;
}
}
if (obj == MP_OBJ_NULL) {
obj = mp_obj_new_exception_msg(&mp_type_RuntimeError, "No active exception to reraise");
RAISE(obj);
}
} else {
obj = POP();
}
obj = mp_make_raise_obj(obj);
RAISE(obj);
}
ENTRY(MP_BC_YIELD_VALUE):
yield:
nlr_pop();
*ip_in_out = ip;
*sp_in_out = sp;
*exc_sp_in_out = MP_TAGPTR_MAKE(exc_sp, currently_in_except_block);
return MP_VM_RETURN_YIELD;
ENTRY(MP_BC_YIELD_FROM): {
//#define EXC_MATCH(exc, type) MP_OBJ_IS_TYPE(exc, type)
#define EXC_MATCH(exc, type) mp_obj_exception_match(exc, type)
#define GENERATOR_EXIT_IF_NEEDED(t) if (t != MP_OBJ_NULL && EXC_MATCH(t, &mp_type_GeneratorExit)) { RAISE(t); }
mp_vm_return_kind_t ret_kind;
mp_obj_t send_value = POP();
mp_obj_t t_exc = MP_OBJ_NULL;
mp_obj_t ret_value;
if (inject_exc != MP_OBJ_NULL) {
t_exc = inject_exc;
inject_exc = MP_OBJ_NULL;
ret_kind = mp_resume(TOP(), MP_OBJ_NULL, t_exc, &ret_value);
} else {
ret_kind = mp_resume(TOP(), send_value, MP_OBJ_NULL, &ret_value);
}
if (ret_kind == MP_VM_RETURN_YIELD) {
ip--;
PUSH(ret_value);
goto yield;
}
if (ret_kind == MP_VM_RETURN_NORMAL) {
// Pop exhausted gen
sp--;
if (ret_value == MP_OBJ_NULL) {
// Optimize StopIteration
// TODO: get StopIteration's value
PUSH(mp_const_none);
} else {
PUSH(ret_value);
}
// If we injected GeneratorExit downstream, then even
// if it was swallowed, we re-raise GeneratorExit
GENERATOR_EXIT_IF_NEEDED(t_exc);
DISPATCH();
}
if (ret_kind == MP_VM_RETURN_EXCEPTION) {
// Pop exhausted gen
sp--;
if (EXC_MATCH(ret_value, &mp_type_StopIteration)) {
PUSH(mp_obj_exception_get_value(ret_value));
// If we injected GeneratorExit downstream, then even
// if it was swallowed, we re-raise GeneratorExit
GENERATOR_EXIT_IF_NEEDED(t_exc);
DISPATCH();
} else {
RAISE(ret_value);
}
}
}
ENTRY(MP_BC_IMPORT_NAME): {
DECODE_QSTR;
mp_obj_t obj = POP();
SET_TOP(mp_import_name(qst, obj, TOP()));
DISPATCH();
}
ENTRY(MP_BC_IMPORT_FROM): {
DECODE_QSTR;
mp_obj_t obj = mp_import_from(TOP(), qst);
PUSH(obj);
DISPATCH();
}
ENTRY(MP_BC_IMPORT_STAR):
mp_import_all(POP());
DISPATCH();
ENTRY_DEFAULT: {
mp_obj_t obj = mp_obj_new_exception_msg(&mp_type_NotImplementedError, "byte code not implemented");
nlr_pop();
fastn[0] = obj;
return MP_VM_RETURN_EXCEPTION;
}
#if !MICROPY_OPT_COMPUTED_GOTO
} // switch
#endif
} // for loop
} else {
exception_handler:
// exception occurred
// check if it's a StopIteration within a for block
if (*save_ip == MP_BC_FOR_ITER && mp_obj_is_subclass_fast(mp_obj_get_type(nlr.ret_val), &mp_type_StopIteration)) {
const byte *ip = save_ip + 1;
machine_uint_t unum;
DECODE_ULABEL; // the jump offset if iteration finishes; for labels are always forward
*ip_in_out = ip + unum; // jump to after for-block
*sp_in_out = save_sp - 1; // pop the exhausted iterator
goto outer_dispatch_loop; // continue with dispatch loop
}
// set file and line number that the exception occurred at
// TODO: don't set traceback for exceptions re-raised by END_FINALLY.
// But consider how to handle nested exceptions.
// TODO need a better way of not adding traceback to constant objects (right now, just GeneratorExit_obj and MemoryError_obj)
if (mp_obj_is_exception_instance(nlr.ret_val) && nlr.ret_val != &mp_const_GeneratorExit_obj && nlr.ret_val != &mp_const_MemoryError_obj) {
machine_uint_t code_info_size = code_info[0] | (code_info[1] << 8) | (code_info[2] << 16) | (code_info[3] << 24);
qstr source_file = code_info[4] | (code_info[5] << 8) | (code_info[6] << 16) | (code_info[7] << 24);
qstr block_name = code_info[8] | (code_info[9] << 8) | (code_info[10] << 16) | (code_info[11] << 24);
machine_uint_t source_line = 1;
machine_uint_t bc = save_ip - code_info - code_info_size;
//printf("find %lu %d %d\n", bc, code_info[12], code_info[13]);
for (const byte* ci = code_info + 12; *ci && bc >= ((*ci) & 31); ci++) {
bc -= *ci & 31;
source_line += *ci >> 5;
}
mp_obj_exception_add_traceback(nlr.ret_val, source_file, source_line, block_name);
}
while (currently_in_except_block) {
// nested exception
assert(exc_sp >= exc_stack);
// TODO make a proper message for nested exception
// at the moment we are just raising the very last exception (the one that caused the nested exception)
// move up to previous exception handler
POP_EXC_BLOCK();
}
if (exc_sp >= exc_stack) {
// set flag to indicate that we are now handling an exception
currently_in_except_block = 1;
// catch exception and pass to byte code
*ip_in_out = exc_sp->handler;
mp_obj_t *sp = MP_TAGPTR_PTR(exc_sp->val_sp);
// save this exception in the stack so it can be used in a reraise, if needed
exc_sp->prev_exc = nlr.ret_val;
// push(traceback, exc-val, exc-type)
PUSH(mp_const_none);
PUSH(nlr.ret_val);
PUSH(mp_obj_get_type(nlr.ret_val));
*sp_in_out = sp;
} else {
// propagate exception to higher level
// TODO what to do about ip and sp? they don't really make sense at this point
fastn[0] = nlr.ret_val; // must put exception here because sp is invalid
return MP_VM_RETURN_EXCEPTION;
}
}
}
}
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