#include #include #include #include #include #include "nlr.h" #include "misc.h" #include "mpyconfig.h" #include "runtime.h" #include "bc.h" #define DECODE_UINT do { unum = *ip++; if (unum > 127) { unum = ((unum & 0x3f) << 8) | (*ip++); } } 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++) // args are in reverse order in array py_obj_t py_execute_byte_code(const byte *code, uint len, const py_obj_t *args, uint n_args) { // careful: be sure to declare volatile any variables read in the exception handler (written is ok, I think) const byte *ip = code; py_obj_t stack[10]; py_obj_t *sp = &stack[10]; // stack grows down, sp points to top of stack machine_uint_t unum; machine_int_t snum; qstr qstr; py_obj_t obj1, obj2; py_obj_t fast0 = NULL, fast1 = NULL, fast2 = NULL, fastn[4] = {NULL, NULL, NULL, NULL}; nlr_buf_t nlr; // on the exception stack we store (ip, sp) for each block machine_uint_t exc_stack[8]; machine_uint_t *volatile exc_sp = &exc_stack[-1]; // stack grows up, exc_sp points to top of stack // init args for (int i = 0; i < n_args; i++) { if (i == 0) { fast0 = args[n_args - 1]; } else if (i == 1) { fast1 = args[n_args - 2]; } else if (i == 2) { fast2 = args[n_args - 3]; } else { assert(i - 3 < 4); fastn[i - 3] = args[n_args - 1 - i]; } } // outer exception handling loop for (;;) { if (nlr_push(&nlr) == 0) { // loop to execute byte code for (;;) { int op = *ip++; switch (op) { case PYBC_LOAD_CONST_FALSE: PUSH(py_const_false); break; case PYBC_LOAD_CONST_NONE: PUSH(py_const_none); break; case PYBC_LOAD_CONST_TRUE: PUSH(py_const_true); break; case PYBC_LOAD_CONST_SMALL_INT: snum = ip[0] | (ip[1] << 8); if (snum & 0x8000) { snum |= ~0xffff; } ip += 2; PUSH((py_obj_t)(snum << 1 | 1)); break; case PYBC_LOAD_CONST_ID: DECODE_QSTR; PUSH(rt_load_const_str(qstr)); // TODO break; case PYBC_LOAD_CONST_STRING: DECODE_QSTR; PUSH(rt_load_const_str(qstr)); break; case PYBC_LOAD_FAST_0: PUSH(fast0); break; case PYBC_LOAD_FAST_1: PUSH(fast1); break; case PYBC_LOAD_FAST_2: PUSH(fast2); break; case PYBC_LOAD_FAST_N: DECODE_UINT; PUSH(fastn[unum - 3]); break; case PYBC_LOAD_NAME: DECODE_QSTR; PUSH(rt_load_name(qstr)); break; case PYBC_LOAD_GLOBAL: DECODE_QSTR; PUSH(rt_load_global(qstr)); break; case PYBC_LOAD_ATTR: DECODE_QSTR; *sp = rt_load_attr(*sp, qstr); break; case PYBC_LOAD_METHOD: DECODE_QSTR; sp -= 1; rt_load_method(sp[1], qstr, sp); break; case PYBC_LOAD_BUILD_CLASS: PUSH(rt_load_build_class()); break; case PYBC_STORE_FAST_0: fast0 = POP(); break; case PYBC_STORE_FAST_1: fast1 = POP(); break; case PYBC_STORE_FAST_2: fast2 = POP(); break; case PYBC_STORE_FAST_N: DECODE_UINT; fastn[unum - 3] = POP(); break; case PYBC_STORE_NAME: DECODE_QSTR; rt_store_name(qstr, POP()); break; case PYBC_STORE_ATTR: DECODE_QSTR; rt_store_attr(sp[0], qstr, sp[1]); sp += 2; break; case PYBC_STORE_SUBSCR: rt_store_subscr(sp[1], sp[0], sp[2]); sp += 3; break; case PYBC_DUP_TOP: obj1 = *sp; PUSH(obj1); break; case PYBC_DUP_TOP_TWO: sp -= 2; sp[0] = sp[2]; sp[1] = sp[3]; break; case PYBC_POP_TOP: ++sp; break; case PYBC_ROT_THREE: obj1 = sp[0]; sp[0] = sp[1]; sp[1] = sp[2]; sp[2] = obj1; break; case PYBC_JUMP: DECODE_UINT; ip = code + unum; break; case PYBC_POP_JUMP_IF_TRUE: DECODE_UINT; if (rt_is_true(POP())) { ip = code + unum; } break; case PYBC_POP_JUMP_IF_FALSE: DECODE_UINT; if (!rt_is_true(POP())) { ip = code + unum; } break; /* we are trying to get away without using this opcode case PYBC_SETUP_LOOP: DECODE_UINT; // push_block(PYBC_SETUP_LOOP, code + unum, sp) break; */ case PYBC_SETUP_EXCEPT: DECODE_UINT; *++exc_sp = (machine_uint_t)code + unum; *++exc_sp = (machine_uint_t)sp; break; case PYBC_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 PYBC_GET_ITER: *sp = rt_getiter(*sp); break; case PYBC_FOR_ITER: DECODE_UINT; // the jump offset if iteration finishes obj1 = rt_iternext(*sp); if (obj1 == py_const_stop_iteration) { ++sp; // pop the exhausted iterator ip = code + unum; // jump to after for-block } else { PUSH(obj1); // push the next iteration value } break; case PYBC_POP_BLOCK: // pops block and restores the stack assert(0); break; case PYBC_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 = (py_obj_t*)(*exc_sp--); //exc_sp--; // discard ip exc_sp -= 2; //sp += 3; // pop 3 exception values assert(sp <= &stack[10]); break; case PYBC_BINARY_OP: unum = *ip++; obj2 = POP(); obj1 = *sp; *sp = rt_binary_op(unum, obj1, obj2); break; case PYBC_COMPARE_OP: unum = *ip++; obj2 = POP(); obj1 = *sp; *sp = rt_compare_op(unum, obj1, obj2); break; case PYBC_BUILD_TUPLE: DECODE_UINT; obj1 = rt_build_tuple(unum, sp); sp += unum - 1; *sp = obj1; break; case PYBC_BUILD_LIST: DECODE_UINT; obj1 = rt_build_list(unum, sp); sp += unum - 1; *sp = obj1; break; case PYBC_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 PYBC_BUILD_MAP: DECODE_UINT; PUSH(rt_build_map(unum)); break; case PYBC_STORE_MAP: sp += 2; rt_store_map(sp[0], sp[-2], sp[-1]); break; case PYBC_BUILD_SET: DECODE_UINT; obj1 = rt_build_set(unum, sp); sp += unum - 1; *sp = obj1; break; case PYBC_MAKE_FUNCTION: DECODE_UINT; PUSH(rt_make_function_from_id(unum)); break; case PYBC_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 PYBC_CALL_METHOD: DECODE_UINT; assert((unum & 0xff00) == 0); // n_keyword unum &= 0xff; obj1 = rt_call_method_n(unum, sp); sp += unum + 1; *sp = obj1; break; case PYBC_RETURN_VALUE: nlr_pop(); assert(sp == &stack[9]); assert(exc_sp == &exc_stack[-1]); return *sp; default: printf("code %p, offset %u, byte code 0x%02x not implemented\n", code, (uint)(ip - code), op); assert(0); nlr_pop(); return py_const_none; } } } else { // exception occurred if (exc_sp >= &exc_stack[0]) { // catch exception and pass to byte code sp = (py_obj_t*)(exc_sp[0]); ip = (const byte*)(exc_sp[-1]); // push(traceback, exc-val, exc-type) PUSH(py_const_none); PUSH(nlr.ret_val); PUSH(py_const_none); } else { // re-raise exception nlr_jump(nlr.ret_val); } } } }