Skip to content
Snippets Groups Projects
Select Git revision
  • e9b4b7ac756273ca14507efc6d92c8b003f99c51
  • wip-bootstrap default
  • dualcore
  • ch3/leds
  • ch3/time
  • master
6 results

vm.c

Blame
  • vm.c 19.80 KiB
    #include <stdint.h>
    #include <stdlib.h>
    #include <stdio.h>
    #include <string.h>
    #include <assert.h>
    
    #include "nlr.h"
    #include "misc.h"
    #include "mpconfig.h"
    #include "obj.h"
    #include "runtime.h"
    #include "bc0.h"
    #include "bc.h"
    
    // (value) stack grows down (to be compatible with native code when passing pointers to the stack), top element is pointed to
    // exception stack grows up, top element is pointed to
    
    #define DECODE_UINT do { unum = *ip++; if (unum > 127) { unum = ((unum & 0x3f) << 8) | (*ip++); } } 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 do { qstr = *ip++; if (qstr > 127) { qstr = ((qstr & 0x3f) << 8) | (*ip++); } } while (0)
    #define PUSH(val) *--sp = (val)
    #define POP() (*sp++)
    #define TOP() (*sp)
    #define SET_TOP(val) *sp = (val)
    
    // args are in reverse order in array
    mp_obj_t mp_execute_byte_code(const byte *code, const mp_obj_t *args, uint n_args, uint n_state) {
        mp_obj_t temp_state[10]; // TODO allocate properly
        mp_obj_t *state = &temp_state[0];
        mp_obj_t *sp = &state[10];
        if (n_state > 10) {
            state = m_new(mp_obj_t, n_state);
            sp = &state[n_state];
        }
        // init args
        for (int i = 0; i < n_args; i++) {
            assert(i < 8);
            state[i] = args[n_args - 1 - i];
        }
        const byte *ip = code;
    
        // execute prelude to make any cells (closed over variables)
        {
            for (uint n_local = *ip++; n_local > 0; n_local--) {
                uint local_num = *ip++;
                if (local_num < n_args) {
                    state[local_num] = mp_obj_new_cell(state[local_num]);
                } else {
                    state[local_num] = mp_obj_new_cell(MP_OBJ_NULL);
                }
            }
        }
    
        // execute the byte code
        if (mp_execute_byte_code_2(&ip, &state[0], &sp)) {
            // it shouldn't yield
            assert(0);
        }
    
        // TODO check fails if, eg, return from within for loop
        //assert(sp == &state[17]);
        return *sp;
    }
    
    // fastn has items in normal order
    // sp points to top of stack which grows down
    bool mp_execute_byte_code_2(const byte **ip_in_out, mp_obj_t *fastn, mp_obj_t **sp_in_out) {
        // careful: be sure to declare volatile any variables read in the exception handler (written is ok, I think)
    
        const byte *ip = *ip_in_out;
        mp_obj_t *sp = *sp_in_out;
        machine_uint_t unum;
        qstr qstr;
        mp_obj_t obj1, obj2;
        mp_obj_t fast0 = fastn[0], fast1 = fastn[1], fast2 = fastn[2];
        nlr_buf_t nlr;
    
        volatile machine_uint_t currently_in_except_block = 0; // 0 or 1, to detect nested exceptions
        machine_uint_t exc_stack[8]; // on the exception stack we store (ip, sp | X) for each block, X = previous value of currently_in_except_block
        machine_uint_t *volatile exc_sp = &exc_stack[0] - 1; // stack grows up, exc_sp points to top of stack
    
        // outer exception handling loop
        for (;;) {
            if (nlr_push(&nlr) == 0) {
                // loop to execute byte code
                for (;;) {
                    int op = *ip++;
                    switch (op) {
                        case MP_BC_LOAD_CONST_FALSE:
                            PUSH(mp_const_false);
                            break;
    
                        case MP_BC_LOAD_CONST_NONE:
                            PUSH(mp_const_none);
                            break;
    
                        case MP_BC_LOAD_CONST_TRUE:
                            PUSH(mp_const_true);
                            break;
    
                        case MP_BC_LOAD_CONST_ELLIPSIS:
                            PUSH(mp_const_ellipsis);
                            break;
    
                        case MP_BC_LOAD_CONST_SMALL_INT:
                            unum = (ip[0] | (ip[1] << 8) | (ip[2] << 16)) - 0x800000;
                            ip += 3;
                            PUSH(MP_OBJ_NEW_SMALL_INT(unum));
                            break;
    
                        case MP_BC_LOAD_CONST_DEC:
                            DECODE_QSTR;
                            PUSH(rt_load_const_dec(qstr));
                            break;
    
                        case MP_BC_LOAD_CONST_ID:
                            DECODE_QSTR;
                            PUSH(rt_load_const_str(qstr)); // TODO
                            break;
    
                        case MP_BC_LOAD_CONST_BYTES:
                            DECODE_QSTR;
                            PUSH(rt_load_const_str(qstr)); // TODO
                            break;
    
                        case MP_BC_LOAD_CONST_STRING:
                            DECODE_QSTR;
                            PUSH(rt_load_const_str(qstr));
                            break;
    
                        case MP_BC_LOAD_FAST_0:
                            PUSH(fast0);
                            break;
    
                        case MP_BC_LOAD_FAST_1:
                            PUSH(fast1);
                            break;
    
                        case MP_BC_LOAD_FAST_2:
                            PUSH(fast2);
                            break;
    
                        case MP_BC_LOAD_FAST_N:
                            DECODE_UINT;
                            PUSH(fastn[unum]);
                            break;
    
                        case MP_BC_LOAD_DEREF:
                            DECODE_UINT;
                            PUSH(rt_get_cell(fastn[unum]));
                            break;
    
                        case MP_BC_LOAD_NAME:
                            DECODE_QSTR;
                            PUSH(rt_load_name(qstr));
                            break;
    
                        case MP_BC_LOAD_GLOBAL:
                            DECODE_QSTR;
                            PUSH(rt_load_global(qstr));
                            break;
    
                        case MP_BC_LOAD_ATTR:
                            DECODE_QSTR;
                            SET_TOP(rt_load_attr(TOP(), qstr));
                            break;
    
                        case MP_BC_LOAD_METHOD:
                            DECODE_QSTR;
                            sp -= 1;
                            rt_load_method(sp[1], qstr, sp);
                            break;
    
                        case MP_BC_LOAD_BUILD_CLASS:
                            PUSH(rt_load_build_class());
                            break;
    
                        case MP_BC_STORE_FAST_0:
                            fast0 = POP();
                            break;
    
                        case MP_BC_STORE_FAST_1:
                            fast1 = POP();
                            break;
    
                        case MP_BC_STORE_FAST_2:
                            fast2 = POP();
                            break;
    
                        case MP_BC_STORE_FAST_N:
                            DECODE_UINT;
                            fastn[unum] = POP();
                            break;
    
                        case MP_BC_STORE_DEREF:
                            DECODE_UINT;
                            rt_set_cell(fastn[unum], POP());
                            break;
    
                        case MP_BC_STORE_NAME:
                            DECODE_QSTR;
                            rt_store_name(qstr, POP());
                            break;
    
                        case MP_BC_STORE_GLOBAL:
                            DECODE_QSTR;
                            rt_store_global(qstr, POP());
                            break;
    
                        case MP_BC_STORE_ATTR:
                            DECODE_QSTR;
                            rt_store_attr(sp[0], qstr, sp[1]);
                            sp += 2;
                            break;
    
                        case MP_BC_STORE_SUBSCR:
                            rt_store_subscr(sp[1], sp[0], sp[2]);
                            sp += 3;
                            break;
    
                        case MP_BC_DUP_TOP:
                            obj1 = TOP();
                            PUSH(obj1);
                            break;
    
                        case MP_BC_DUP_TOP_TWO:
                            sp -= 2;
                            sp[0] = sp[2];
                            sp[1] = sp[3];
                            break;
    
                        case MP_BC_POP_TOP:
                            ++sp;
                            break;
    
                        case MP_BC_ROT_TWO:
                            obj1 = sp[0];
                            sp[0] = sp[1];
                            sp[1] = obj1;
                            break;
    
                        case MP_BC_ROT_THREE:
                            obj1 = sp[0];
                            sp[0] = sp[1];
                            sp[1] = sp[2];
                            sp[2] = obj1;
                            break;
    
                        case MP_BC_JUMP:
                            DECODE_SLABEL;
                            ip += unum;
                            break;
    
                        case MP_BC_POP_JUMP_IF_TRUE:
                            DECODE_SLABEL;
                            if (rt_is_true(POP())) {
                                ip += unum;
                            }
                            break;
    
                        case MP_BC_POP_JUMP_IF_FALSE:
                            DECODE_SLABEL;
                            if (!rt_is_true(POP())) {
                                ip += unum;
                            }
                            break;
    
                        case MP_BC_JUMP_IF_TRUE_OR_POP:
                            DECODE_SLABEL;
                            if (rt_is_true(TOP())) {
                                ip += unum;
                            } else {
                                sp++;
                            }
                            break;
    
                        case MP_BC_JUMP_IF_FALSE_OR_POP:
                            DECODE_SLABEL;
                            if (rt_is_true(TOP())) {
                                sp++;
                            } else {
                                ip += unum;
                            }
                            break;
    
                            /* we are trying to get away without using this opcode
                        case MP_BC_SETUP_LOOP:
                            DECODE_UINT;
                            // push_block(MP_BC_SETUP_LOOP, ip + unum, sp)
                            break;
                            */
    
                        // matched against: POP_BLOCK or POP_EXCEPT (anything else?)
                        case MP_BC_SETUP_EXCEPT:
                            DECODE_ULABEL; // except labels are always forward
                            *++exc_sp = (machine_uint_t)ip + unum;
                            *++exc_sp = (((machine_uint_t)sp) | currently_in_except_block);
                            currently_in_except_block = 0; // in a try block now
                            break;
    
                        case MP_BC_END_FINALLY:
                            // not implemented
                            // if TOS is an exception, reraises the exception (3 values on TOS)
                            // if TOS is an integer, does something else
                            // if TOS is None, just pops it and continues
                            // else error
                            assert(0);
                            break;
    
                        case MP_BC_GET_ITER:
                            SET_TOP(rt_getiter(TOP()));
                            break;
    
                        case MP_BC_FOR_ITER:
                            DECODE_ULABEL; // the jump offset if iteration finishes; for labels are always forward
                            obj1 = rt_iternext(TOP());
                            if (obj1 == mp_const_stop_iteration) {
                                ++sp; // pop the exhausted iterator
                                ip += unum; // jump to after for-block
                            } else {
                                PUSH(obj1); // push the next iteration value
                            }
                            break;
    
                        // matched against: SETUP_EXCEPT, SETUP_FINALLY, SETUP_WITH
                        case MP_BC_POP_BLOCK:
                            // we are exiting an exception handler, so pop the last one of the exception-stack
                            assert(exc_sp >= &exc_stack[0]);
                            currently_in_except_block = (exc_sp[0] & 1); // restore previous state
                            exc_sp -= 2; // pop back to previous exception handler
                            break;
    
                        // matched againts: SETUP_EXCEPT
                        case 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[0]);
                            //sp = (mp_obj_t*)(*exc_sp--);
                            //exc_sp--; // discard ip
                            currently_in_except_block = (exc_sp[0] & 1); // restore previous state
                            exc_sp -= 2; // pop back to previous exception handler
                            //sp += 3; // pop 3 exception values
                            break;
    
                        case MP_BC_UNARY_OP:
                            unum = *ip++;
                            SET_TOP(rt_unary_op(unum, TOP()));
                            break;
    
                        case MP_BC_BINARY_OP:
                            unum = *ip++;
                            obj2 = POP();
                            obj1 = TOP();
                            SET_TOP(rt_binary_op(unum, obj1, obj2));
                            break;
    
                        case MP_BC_COMPARE_OP:
                            unum = *ip++;
                            obj2 = POP();
                            obj1 = TOP();
                            SET_TOP(rt_compare_op(unum, obj1, obj2));
                            break;
    
                        case MP_BC_BUILD_TUPLE:
                            DECODE_UINT;
                            obj1 = rt_build_tuple(unum, sp);
                            sp += unum - 1;
                            SET_TOP(obj1);
                            break;
    
                        case MP_BC_BUILD_LIST:
                            DECODE_UINT;
                            obj1 = rt_build_list(unum, sp);
                            sp += unum - 1;
                            SET_TOP(obj1);
                            break;
    
                        case MP_BC_LIST_APPEND:
                            DECODE_UINT;
                            // I think it's guaranteed by the compiler that sp[unum] is a list
                            rt_list_append(sp[unum], sp[0]);
                            sp++;
                            break;
    
                        case MP_BC_BUILD_MAP:
                            DECODE_UINT;
                            PUSH(rt_build_map(unum));
                            break;
    
                        case MP_BC_STORE_MAP:
                            sp += 2;
                            rt_store_map(sp[0], sp[-2], sp[-1]);
                            break;
    
                        case MP_BC_MAP_ADD:
                            DECODE_UINT;
                            // I think it's guaranteed by the compiler that sp[unum + 1] is a map
                            rt_store_map(sp[unum + 1], sp[0], sp[1]);
                            sp += 2;
                            break;
    
                        case MP_BC_BUILD_SET:
                            DECODE_UINT;
                            obj1 = rt_build_set(unum, sp);
                            sp += unum - 1;
                            SET_TOP(obj1);
                            break;
    
                        case MP_BC_SET_ADD:
                            DECODE_UINT;
                            // I think it's guaranteed by the compiler that sp[unum] is a set
                            rt_store_set(sp[unum], sp[0]);
                            sp++;
                            break;
    
    #if MICROPY_ENABLE_SLICE
                        case MP_BC_BUILD_SLICE:
                            DECODE_UINT;
                            if (unum == 2) {
                                obj2 = POP();
                                obj1 = TOP();
                                SET_TOP(mp_obj_new_slice(obj1, obj2, NULL));
                            } else {
                                printf("3-argument slice is not supported\n");
                                assert(0);
                            }
                            break;
    #endif
    
                        case MP_BC_UNPACK_SEQUENCE:
                            DECODE_UINT;
                            rt_unpack_sequence(sp[0], unum, sp - unum + 1);
                            sp -= unum - 1;
                            break;
    
                        case MP_BC_MAKE_FUNCTION:
                            DECODE_UINT;
                            PUSH(rt_make_function_from_id(unum));
                            break;
    
                        case MP_BC_MAKE_CLOSURE:
                            DECODE_UINT;
                            obj1 = POP();
                            PUSH(rt_make_closure_from_id(unum, obj1));
                            break;
    
                        case MP_BC_CALL_FUNCTION:
                            DECODE_UINT;
                            assert((unum & 0xff00) == 0); // n_keyword
                            unum &= 0xff; // n_positional
                            sp += unum;
                            *sp = rt_call_function_n(*sp, unum, sp - unum);
                            break;
    
                        case MP_BC_CALL_METHOD:
                            DECODE_UINT;
                            if ((unum & 0xff00) == 0) {
                                // no keywords
                                unum &= 0xff;
                                obj1 = rt_call_method_n(unum, sp);
                                sp += unum + 1;
                            } else {
                                // keywords
                                obj1 = rt_call_method_n_kw(unum & 0xff, (unum >> 8) & 0xff, sp);
                                sp += (unum & 0xff) + ((unum >> 7) & 0x1fe) + 1;
                            }
                            SET_TOP(obj1);
                            break;
    
                        case MP_BC_RETURN_VALUE:
                            nlr_pop();
                            *sp_in_out = sp;
                            assert(exc_sp == &exc_stack[0] - 1);
                            return false;
    
                        case MP_BC_RAISE_VARARGS:
                            unum = *ip++;
                            assert(unum == 1);
                            obj1 = POP();
                            nlr_jump(obj1);
                            return false;
    
                        case MP_BC_YIELD_VALUE:
                            nlr_pop();
                            *ip_in_out = ip;
                            fastn[0] = fast0;
                            fastn[1] = fast1;
                            fastn[2] = fast2;
                            *sp_in_out = sp;
                            return true;
    
                        case MP_BC_IMPORT_NAME:
                            DECODE_QSTR;
                            obj1 = POP();
                            SET_TOP(rt_import_name(qstr, obj1, TOP()));
                            break;
    
                        case MP_BC_IMPORT_FROM:
                            DECODE_QSTR;
                            obj1 = rt_import_from(TOP(), qstr);
                            PUSH(obj1);
                            break;
    
                        default:
                            printf("code %p, byte code 0x%02x not implemented\n", ip, op);
                            assert(0);
                            nlr_pop();
                            return false;
                    }
                }
    
            } else {
                // exception occurred
    
                while (currently_in_except_block) {
                    // nested exception
    
                    assert(exc_sp >= &exc_stack[0]);
    
                    // 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
                    currently_in_except_block = (exc_sp[0] & 1); // restore previous state
                    exc_sp -= 2; // pop back to previous exception handler
                }
    
                if (exc_sp >= &exc_stack[0]) {
                    // set flag to indicate that we are now handling an exception
                    currently_in_except_block = 1;
    
                    // catch exception and pass to byte code
                    sp = (mp_obj_t*)(exc_sp[0] & (~((machine_uint_t)1)));
                    ip = (const byte*)(exc_sp[-1]);
                    // push(traceback, exc-val, exc-type)
                    PUSH(mp_const_none);
                    PUSH(nlr.ret_val);
                    PUSH(nlr.ret_val); // TODO should be type(nlr.ret_val), I think...
    
                } else {
                    // re-raise exception to higher level
                    // TODO what to do if this is a generator??
                    nlr_jump(nlr.ret_val);
                }
            }
        }
    }