#include #include #include "nlr.h" #include "misc.h" #include "mpconfig.h" #include "qstr.h" #include "obj.h" #include "runtime.h" #include "bc0.h" #include "bc.h" #include "objgenerator.h" // 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 { \ unum = 0; \ do { \ unum = (unum << 7) + (*ip & 0x7f); \ } while ((*ip++ & 0x80) != 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 { \ qst = 0; \ do { \ qst = (qst << 7) + (*ip & 0x7f); \ } while ((*ip++ & 0x80) != 0); \ } #define PUSH(val) *++sp = (val) #define POP() (*sp--) #define TOP() (*sp) #define SET_TOP(val) *sp = (val) mp_vm_return_kind_t mp_execute_byte_code(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[10]; mp_obj_t *state = &temp_state[0]; if (n_state > 10) { state = m_new(mp_obj_t, n_state); } mp_obj_t *sp = &state[0] - 1; // allocate state for exceptions mp_exc_stack exc_state[4]; mp_exc_stack *exc_stack = &exc_state[0]; if (n_exc_stack > 4) { exc_stack = m_new(mp_exc_stack, n_exc_stack); } mp_exc_stack *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]; } // bytecode prelude: initialise closed over variables for (uint n_local = *ip++; n_local > 0; n_local--) { uint local_num = *ip++; if (local_num < n_args + n_args2) { state[n_state - 1 - local_num] = mp_obj_new_cell(state[n_state - 1 - local_num]); } else { state[n_state - 1 - local_num] = mp_obj_new_cell(MP_OBJ_NULL); } } // execute the byte code mp_vm_return_kind_t vm_return_kind = mp_execute_byte_code_2(code, &ip, &state[n_state - 1], &sp, exc_stack, &exc_sp, MP_OBJ_NULL); switch (vm_return_kind) { case MP_VM_RETURN_NORMAL: *ret = *sp; return MP_VM_RETURN_NORMAL; case MP_VM_RETURN_EXCEPTION: *ret = state[n_state - 1]; return MP_VM_RETURN_EXCEPTION; case MP_VM_RETURN_YIELD: // byte-code shouldn't yield default: assert(0); *ret = mp_const_none; return MP_VM_RETURN_NORMAL; } } // 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_byte_code_2(const byte *code_info, const byte **ip_in_out, mp_obj_t *fastn, mp_obj_t **sp_in_out, mp_exc_stack *exc_stack, mp_exc_stack **exc_sp_in_out, volatile mp_obj_t inject_exc) { // 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 qst; mp_obj_t obj1, obj2; nlr_buf_t nlr; volatile bool currently_in_except_block = MP_TAGPTR_TAG(*exc_sp_in_out); // 0 or 1, to detect nested exceptions mp_exc_stack *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; // 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) // outer exception handling loop for (;;) { outer_dispatch_loop: if (nlr_push(&nlr) == 0) { // 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 t = inject_exc; inject_exc = MP_OBJ_NULL; nlr_jump(rt_make_raise_obj(t)); } // loop to execute byte code for (;;) { dispatch_loop: save_ip = ip; 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: { 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)); break; } case MP_BC_LOAD_CONST_INT: DECODE_QSTR; PUSH(mp_obj_new_int_from_long_str(qstr_str(qst))); break; case MP_BC_LOAD_CONST_DEC: DECODE_QSTR; PUSH(rt_load_const_dec(qst)); break; case MP_BC_LOAD_CONST_ID: DECODE_QSTR; PUSH(rt_load_const_str(qst)); // TODO break; case MP_BC_LOAD_CONST_BYTES: DECODE_QSTR; PUSH(rt_load_const_bytes(qst)); break; case MP_BC_LOAD_CONST_STRING: DECODE_QSTR; PUSH(rt_load_const_str(qst)); break; case MP_BC_LOAD_FAST_0: PUSH(fastn[0]); break; case MP_BC_LOAD_FAST_1: PUSH(fastn[-1]); break; case MP_BC_LOAD_FAST_2: PUSH(fastn[-2]); 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(qst)); break; case MP_BC_LOAD_GLOBAL: DECODE_QSTR; PUSH(rt_load_global(qst)); break; case MP_BC_LOAD_ATTR: DECODE_QSTR; SET_TOP(rt_load_attr(TOP(), qst)); break; case MP_BC_LOAD_METHOD: DECODE_QSTR; rt_load_method(*sp, qst, sp); sp += 1; break; case MP_BC_LOAD_BUILD_CLASS: PUSH(rt_load_build_class()); break; case MP_BC_STORE_FAST_0: fastn[0] = POP(); break; case MP_BC_STORE_FAST_1: fastn[-1] = POP(); break; case MP_BC_STORE_FAST_2: fastn[-2] = 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(qst, POP()); break; case MP_BC_STORE_GLOBAL: DECODE_QSTR; rt_store_global(qst, POP()); break; case MP_BC_STORE_ATTR: DECODE_QSTR; rt_store_attr(sp[0], qst, 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_DELETE_NAME: DECODE_QSTR; rt_delete_name(qst); 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 -= 1; 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; */ case 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 unwind_jump: unum = (machine_uint_t)POP(); // get number of exception handlers to unwind while (unum > 0) { unum -= 1; assert(exc_sp >= exc_stack); if (exc_sp->opcode == MP_BC_SETUP_FINALLY) { // 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 break; // matched against: POP_BLOCK or POP_EXCEPT (anything else?) case MP_BC_SETUP_EXCEPT: case MP_BC_SETUP_FINALLY: DECODE_ULABEL; // except labels are always forward ++exc_sp; exc_sp->opcode = op; exc_sp->handler = ip + unum; exc_sp->val_sp = MP_TAGPTR_MAKE(sp, currently_in_except_block); currently_in_except_block = 0; // in a try block now break; case 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_instance(TOP())) { nlr_jump(TOP()); } 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); } 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_allow_raise(TOP()); if (obj1 == MP_OBJ_NULL) { --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); currently_in_except_block = MP_TAGPTR_TAG(exc_sp->val_sp); // restore previous state exc_sp--; // pop back to previous exception handler break; // matched against: 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); assert(currently_in_except_block); //sp = (mp_obj_t*)(*exc_sp--); //exc_sp--; // discard ip currently_in_except_block = MP_TAGPTR_TAG(exc_sp->val_sp); // restore previous state exc_sp--; // pop back to previous exception handler //sp -= 3; // pop 3 exception values break; case MP_BC_NOT: if (TOP() == mp_const_true) { SET_TOP(mp_const_false); } else { SET_TOP(mp_const_true); } 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_BUILD_TUPLE: DECODE_UINT; sp -= unum - 1; SET_TOP(rt_build_tuple(unum, sp)); break; case MP_BC_BUILD_LIST: DECODE_UINT; sp -= unum - 1; SET_TOP(rt_build_list(unum, sp)); 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; sp -= unum - 1; SET_TOP(rt_build_set(unum, sp)); 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); sp += unum - 1; break; case MP_BC_MAKE_FUNCTION: DECODE_UINT; PUSH(rt_make_function_from_id(unum, MP_OBJ_NULL)); break; case MP_BC_MAKE_FUNCTION_DEFARGS: DECODE_UINT; SET_TOP(rt_make_function_from_id(unum, TOP())); break; case MP_BC_MAKE_CLOSURE: DECODE_UINT; SET_TOP(rt_make_closure_from_id(unum, TOP(), MP_OBJ_NULL)); break; case MP_BC_MAKE_CLOSURE_DEFARGS: DECODE_UINT; obj1 = POP(); SET_TOP(rt_make_closure_from_id(unum, obj1, TOP())); break; case MP_BC_CALL_FUNCTION: DECODE_UINT; // unum & 0xff == n_positional // (unum >> 8) & 0xff == n_keyword sp -= (unum & 0xff) + ((unum >> 7) & 0x1fe); SET_TOP(rt_call_function_n_kw(*sp, unum & 0xff, (unum >> 8) & 0xff, sp + 1)); break; case MP_BC_CALL_METHOD: DECODE_UINT; // unum & 0xff == n_positional // (unum >> 8) & 0xff == n_keyword sp -= (unum & 0xff) + ((unum >> 7) & 0x1fe) + 1; SET_TOP(rt_call_method_n_kw(unum & 0xff, (unum >> 8) & 0xff, sp)); break; case MP_BC_RETURN_VALUE: unwind_return: while (exc_sp >= exc_stack) { if (exc_sp->opcode == MP_BC_SETUP_FINALLY) { // 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; case MP_BC_RAISE_VARARGS: unum = *ip++; assert(unum <= 1); if (unum == 0) { // This assumes that nlr.ret_val holds last raised // exception and is not overwritten since then. obj1 = nlr.ret_val; } else { obj1 = POP(); } nlr_jump(rt_make_raise_obj(obj1)); case 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; case 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) mp_vm_return_kind_t ret_kind; obj1 = POP(); mp_obj_t t = MP_OBJ_NULL; if (inject_exc != MP_OBJ_NULL) { t = inject_exc; inject_exc = MP_OBJ_NULL; obj2 = mp_obj_gen_resume(TOP(), mp_const_none, t, &ret_kind); } else { obj2 = mp_obj_gen_resume(TOP(), obj1, MP_OBJ_NULL, &ret_kind); } if (ret_kind == MP_VM_RETURN_YIELD) { ip--; PUSH(obj2); goto yield; } if (ret_kind == MP_VM_RETURN_NORMAL) { // Pop exhausted gen sp--; if (obj2 == MP_OBJ_NULL) { // Optimize StopIteration // TODO: get StopIteration's value PUSH(mp_const_none); } else { PUSH(obj2); } // if it swallowed it, we re-raise GeneratorExit if (t != MP_OBJ_NULL && EXC_MATCH(t, &mp_type_GeneratorExit)) { nlr_jump(t); } break; } if (ret_kind == MP_VM_RETURN_EXCEPTION) { // Pop exhausted gen sp--; if (EXC_MATCH(obj2, &mp_type_StopIteration)) { printf("Generator explicitly raised StopIteration\n"); PUSH(mp_const_none); break; } else { nlr_jump(obj2); } } } case MP_BC_IMPORT_NAME: DECODE_QSTR; obj1 = POP(); SET_TOP(rt_import_name(qst, obj1, TOP())); break; case MP_BC_IMPORT_FROM: DECODE_QSTR; obj1 = rt_import_from(TOP(), qst); PUSH(obj1); break; case MP_BC_IMPORT_STAR: rt_import_all(POP()); break; default: printf("code %p, byte code 0x%02x not implemented\n", ip, op); assert(0); nlr_pop(); return MP_VM_RETURN_NORMAL; } } } else { // 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)) { ip = save_ip + 1; DECODE_ULABEL; // the jump offset if iteration finishes; for labels are always forward --sp; // pop the exhausted iterator ip += unum; // jump to after for-block 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. if (mp_obj_is_exception_instance(nlr.ret_val)) { 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 currently_in_except_block = MP_TAGPTR_TAG(exc_sp->val_sp); // restore previous state exc_sp--; // pop back to previous exception handler } 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 sp = MP_TAGPTR_PTR(exc_sp->val_sp); ip = exc_sp->handler; // 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 { // 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; } } } }