vm.c 26.5 KB
Newer Older
Damien's avatar
Damien committed
1
2
3
4
5
6
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>

7
#include "nlr.h"
Damien's avatar
Damien committed
8
#include "misc.h"
9
#include "mpconfig.h"
10
#include "qstr.h"
11
#include "obj.h"
Damien's avatar
Damien committed
12
#include "runtime.h"
13
#include "bc0.h"
14
#include "bc.h"
Damien's avatar
Damien committed
15

Paul Sokolovsky's avatar
Paul Sokolovsky committed
16
17
18
19
20
21
22
// 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.

23
24
25
26
27
28
29
30
31
32
// Exception stack entry
typedef struct _mp_exc_stack {
    const byte *handler;
    // bit 0 is saved currently_in_except_block value
    machine_uint_t val_sp;
    // We might only have 2 interesting cases here: SETUP_EXCEPT & SETUP_FINALLY,
    // consider storing it in bit 1 of val_sp. TODO: SETUP_WITH?
    byte opcode;
} mp_exc_stack;

33
// Exception stack unwind reasons (WHY_* in CPython-speak)
34
35
// TODO perhaps compress this to RETURN=0, JUMP>0, with number of unwinds
// left to do encoded in the JUMP number
36
37
typedef enum {
    UNWIND_RETURN = 1,
38
    UNWIND_JUMP,
39
40
} mp_unwind_reason_t;

41
42
43
44
45
46
#define DECODE_UINT { \
    unum = 0; \
    do { \
        unum = (unum << 7) + (*ip & 0x7f); \
    } while ((*ip++ & 0x80) != 0); \
}
Damien's avatar
Damien committed
47
48
#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)
49
50
51
52
53
54
#define DECODE_QSTR { \
    qst = 0; \
    do { \
        qst = (qst << 7) + (*ip & 0x7f); \
    } while ((*ip++ & 0x80) != 0); \
}
55
56
#define PUSH(val) *++sp = (val)
#define POP() (*sp--)
57
58
#define TOP() (*sp)
#define SET_TOP(val) *sp = (val)
Damien's avatar
Damien committed
59

60
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, uint n_state, mp_obj_t *ret) {
61
62
    // allocate state for locals and stack
    mp_obj_t temp_state[10];
63
    mp_obj_t *state = &temp_state[0];
64
    if (n_state > 10) {
65
        state = m_new(mp_obj_t, n_state);
66
    }
67
68
    mp_obj_t *sp = &state[0] - 1;

69
    // init args
70
    for (uint i = 0; i < n_args; i++) {
71
        state[n_state - 1 - i] = args[i];
72
    }
73
74
75
    for (uint i = 0; i < n_args2; i++) {
        state[n_state - 1 - n_args - i] = args2[i];
    }
76

77
    const byte *ip = code;
Damien George's avatar
Damien George committed
78

79
80
81
82
    // get code info size
    machine_uint_t code_info_size = ip[0] | (ip[1] << 8) | (ip[2] << 16) | (ip[3] << 24);
    ip += code_info_size;

Damien George's avatar
Damien George committed
83
84
85
86
    // execute prelude to make any cells (closed over variables)
    {
        for (uint n_local = *ip++; n_local > 0; n_local--) {
            uint local_num = *ip++;
87
            if (local_num < n_args + n_args2) {
88
                state[n_state - 1 - local_num] = mp_obj_new_cell(state[n_state - 1 - local_num]);
Damien George's avatar
Damien George committed
89
            } else {
90
                state[n_state - 1 - local_num] = mp_obj_new_cell(MP_OBJ_NULL);
Damien George's avatar
Damien George committed
91
92
93
94
95
            }
        }
    }

    // execute the byte code
96
97
98
99
100
101
102
103
104
105
106
107
108
109
    mp_vm_return_kind_t vm_return_kind = mp_execute_byte_code_2(code, &ip, &state[n_state - 1], &sp);

    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;
110
111
112
    }
}

113
114
// 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
115
116
117
118
119
// 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) {
Damien's avatar
Damien committed
120
121
    // careful: be sure to declare volatile any variables read in the exception handler (written is ok, I think)

122
    const byte *ip = *ip_in_out;
123
    mp_obj_t *sp = *sp_in_out;
Damien's avatar
Damien committed
124
    machine_uint_t unum;
125
    qstr qst;
126
    mp_obj_t obj1, obj2;
127
    nlr_buf_t nlr;
Damien's avatar
Damien committed
128

129
    volatile machine_uint_t currently_in_except_block = 0; // 0 or 1, to detect nested exceptions
130
131
    mp_exc_stack exc_stack[4];
    mp_exc_stack *volatile exc_sp = &exc_stack[0] - 1; // stack grows up, exc_sp points to top of stack
132
    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)
Damien's avatar
Damien committed
133

134
    // outer exception handling loop
Damien's avatar
Damien committed
135
    for (;;) {
136
137
138
        if (nlr_push(&nlr) == 0) {
            // loop to execute byte code
            for (;;) {
139
dispatch_loop:
140
                save_ip = ip;
141
142
                int op = *ip++;
                switch (op) {
143
144
                    case MP_BC_LOAD_CONST_FALSE:
                        PUSH(mp_const_false);
145
146
                        break;

147
148
                    case MP_BC_LOAD_CONST_NONE:
                        PUSH(mp_const_none);
149
150
                        break;

151
152
                    case MP_BC_LOAD_CONST_TRUE:
                        PUSH(mp_const_true);
153
                        break;
Damien George's avatar
Damien George committed
154
155
156
157

                    case MP_BC_LOAD_CONST_ELLIPSIS:
                        PUSH(mp_const_ellipsis);
                        break;
158

159
                    case MP_BC_LOAD_CONST_SMALL_INT:
Damien's avatar
Damien committed
160
                        unum = (ip[0] | (ip[1] << 8) | (ip[2] << 16)) - 0x800000;
161
                        ip += 3;
162
                        PUSH(MP_OBJ_NEW_SMALL_INT(unum));
163
164
                        break;

165
166
                    case MP_BC_LOAD_CONST_INT:
                        DECODE_QSTR;
167
                        PUSH(mp_obj_new_int_from_long_str(qstr_str(qst)));
168
169
                        break;

170
                    case MP_BC_LOAD_CONST_DEC:
Damien's avatar
Damien committed
171
                        DECODE_QSTR;
172
                        PUSH(rt_load_const_dec(qst));
Damien's avatar
Damien committed
173
174
                        break;

175
                    case MP_BC_LOAD_CONST_ID:
176
                        DECODE_QSTR;
177
                        PUSH(rt_load_const_str(qst)); // TODO
178
179
                        break;

180
181
                    case MP_BC_LOAD_CONST_BYTES:
                        DECODE_QSTR;
182
                        PUSH(rt_load_const_bytes(qst));
183
184
                        break;

185
                    case MP_BC_LOAD_CONST_STRING:
186
                        DECODE_QSTR;
187
                        PUSH(rt_load_const_str(qst));
188
189
                        break;

190
                    case MP_BC_LOAD_FAST_0:
191
                        PUSH(fastn[0]);
192
193
                        break;

194
                    case MP_BC_LOAD_FAST_1:
195
                        PUSH(fastn[-1]);
196
197
                        break;

198
                    case MP_BC_LOAD_FAST_2:
199
                        PUSH(fastn[-2]);
200
201
                        break;

202
                    case MP_BC_LOAD_FAST_N:
203
                        DECODE_UINT;
204
                        PUSH(fastn[-unum]);
205
206
                        break;

207
                    case MP_BC_LOAD_DEREF:
Damien's avatar
Damien committed
208
                        DECODE_UINT;
209
                        PUSH(rt_get_cell(fastn[-unum]));
Damien's avatar
Damien committed
210
211
                        break;

212
                    case MP_BC_LOAD_NAME:
213
                        DECODE_QSTR;
214
                        PUSH(rt_load_name(qst));
215
216
                        break;

217
                    case MP_BC_LOAD_GLOBAL:
218
                        DECODE_QSTR;
219
                        PUSH(rt_load_global(qst));
220
221
                        break;

222
                    case MP_BC_LOAD_ATTR:
223
                        DECODE_QSTR;
224
                        SET_TOP(rt_load_attr(TOP(), qst));
225
226
                        break;

227
                    case MP_BC_LOAD_METHOD:
228
                        DECODE_QSTR;
229
                        rt_load_method(*sp, qst, sp);
230
                        sp += 1;
231
232
                        break;

233
                    case MP_BC_LOAD_BUILD_CLASS:
234
235
236
                        PUSH(rt_load_build_class());
                        break;

237
                    case MP_BC_STORE_FAST_0:
238
                        fastn[0] = POP();
239
240
                        break;

241
                    case MP_BC_STORE_FAST_1:
242
                        fastn[-1] = POP();
243
244
                        break;

245
                    case MP_BC_STORE_FAST_2:
246
                        fastn[-2] = POP();
247
248
                        break;

249
                    case MP_BC_STORE_FAST_N:
250
                        DECODE_UINT;
251
                        fastn[-unum] = POP();
252
253
                        break;

254
                    case MP_BC_STORE_DEREF:
Damien's avatar
Damien committed
255
                        DECODE_UINT;
256
                        rt_set_cell(fastn[-unum], POP());
Damien's avatar
Damien committed
257
258
                        break;

259
                    case MP_BC_STORE_NAME:
260
                        DECODE_QSTR;
261
                        rt_store_name(qst, POP());
262
263
                        break;

264
                    case MP_BC_STORE_GLOBAL:
265
                        DECODE_QSTR;
266
                        rt_store_global(qst, POP());
267
268
                        break;

269
                    case MP_BC_STORE_ATTR:
270
                        DECODE_QSTR;
271
                        rt_store_attr(sp[0], qst, sp[-1]);
272
                        sp -= 2;
273
274
                        break;

275
                    case MP_BC_STORE_SUBSCR:
276
277
                        rt_store_subscr(sp[-1], sp[0], sp[-2]);
                        sp -= 3;
278
279
                        break;

280
                    case MP_BC_DUP_TOP:
281
                        obj1 = TOP();
282
283
284
                        PUSH(obj1);
                        break;

285
                    case MP_BC_DUP_TOP_TWO:
286
287
288
                        sp += 2;
                        sp[0] = sp[-2];
                        sp[-1] = sp[-3];
289
290
                        break;

291
                    case MP_BC_POP_TOP:
292
                        sp -= 1;
293
294
                        break;

295
                    case MP_BC_ROT_TWO:
296
                        obj1 = sp[0];
297
298
                        sp[0] = sp[-1];
                        sp[-1] = obj1;
299
300
                        break;

301
                    case MP_BC_ROT_THREE:
302
                        obj1 = sp[0];
303
304
305
                        sp[0] = sp[-1];
                        sp[-1] = sp[-2];
                        sp[-2] = obj1;
306
307
                        break;

308
                    case MP_BC_JUMP:
Damien's avatar
Damien committed
309
310
                        DECODE_SLABEL;
                        ip += unum;
311
312
                        break;

313
                    case MP_BC_POP_JUMP_IF_TRUE:
Damien's avatar
Damien committed
314
                        DECODE_SLABEL;
315
                        if (rt_is_true(POP())) {
Damien's avatar
Damien committed
316
                            ip += unum;
317
318
319
                        }
                        break;

320
                    case MP_BC_POP_JUMP_IF_FALSE:
Damien's avatar
Damien committed
321
                        DECODE_SLABEL;
322
                        if (!rt_is_true(POP())) {
Damien's avatar
Damien committed
323
                            ip += unum;
324
325
326
                        }
                        break;

327
                    case MP_BC_JUMP_IF_TRUE_OR_POP:
Damien's avatar
Damien committed
328
                        DECODE_SLABEL;
329
                        if (rt_is_true(TOP())) {
Damien's avatar
Damien committed
330
331
                            ip += unum;
                        } else {
332
                            sp--;
Damien's avatar
Damien committed
333
334
335
                        }
                        break;

336
                    case MP_BC_JUMP_IF_FALSE_OR_POP:
Damien's avatar
Damien committed
337
                        DECODE_SLABEL;
338
                        if (rt_is_true(TOP())) {
339
                            sp--;
Damien's avatar
Damien committed
340
341
342
343
344
                        } else {
                            ip += unum;
                        }
                        break;

345
                        /* we are trying to get away without using this opcode
346
                    case MP_BC_SETUP_LOOP:
347
                        DECODE_UINT;
348
                        // push_block(MP_BC_SETUP_LOOP, ip + unum, sp)
349
350
351
                        break;
                        */

352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
                    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
375
376
                        break;

Damien's avatar
Damien committed
377
                    // matched against: POP_BLOCK or POP_EXCEPT (anything else?)
378
                    case MP_BC_SETUP_EXCEPT:
379
                    case MP_BC_SETUP_FINALLY:
Damien's avatar
Damien committed
380
                        DECODE_ULABEL; // except labels are always forward
381
382
383
384
                        ++exc_sp;
                        exc_sp->opcode = op;
                        exc_sp->handler = ip + unum;
                        exc_sp->val_sp = (((machine_uint_t)sp) | currently_in_except_block);
385
                        currently_in_except_block = 0; // in a try block now
386
387
                        break;

388
                    case MP_BC_END_FINALLY:
389
                        // not fully implemented
390
391
                        // if TOS is an exception, reraises the exception (3 values on TOS)
                        // if TOS is None, just pops it and continues
392
                        // if TOS is an integer, does something else
393
                        // else error
394
                        if (mp_obj_is_exception_instance(TOP())) {
395
396
397
398
                            nlr_jump(TOP());
                        }
                        if (TOP() == mp_const_none) {
                            sp--;
399
400
401
402
403
404
405
                        } 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;
406
407
                                case UNWIND_JUMP:
                                    goto unwind_jump;
408
409
                            }
                            assert(0);
410
411
412
                        } else {
                            assert(0);
                        }
413
414
                        break;

415
                    case MP_BC_GET_ITER:
416
                        SET_TOP(rt_getiter(TOP()));
417
418
                        break;

419
                    case MP_BC_FOR_ITER:
Damien's avatar
Damien committed
420
                        DECODE_ULABEL; // the jump offset if iteration finishes; for labels are always forward
421
                        obj1 = rt_iternext(TOP());
422
                        if (obj1 == mp_const_stop_iteration) {
423
                            --sp; // pop the exhausted iterator
Damien's avatar
Damien committed
424
                            ip += unum; // jump to after for-block
425
426
427
428
429
                        } else {
                            PUSH(obj1); // push the next iteration value
                        }
                        break;

Damien's avatar
Damien committed
430
                    // matched against: SETUP_EXCEPT, SETUP_FINALLY, SETUP_WITH
431
                    case MP_BC_POP_BLOCK:
Damien's avatar
Damien committed
432
433
                        // we are exiting an exception handler, so pop the last one of the exception-stack
                        assert(exc_sp >= &exc_stack[0]);
434
435
                        currently_in_except_block = (exc_sp->val_sp & 1); // restore previous state
                        exc_sp--; // pop back to previous exception handler
436
437
                        break;

438
                    // matched against: SETUP_EXCEPT
439
                    case MP_BC_POP_EXCEPT:
Damien's avatar
Damien committed
440
                        // TODO need to work out how blocks work etc
441
                        // pops block, checks it's an exception block, and restores the stack, saving the 3 exception values to local threadstate
Damien's avatar
Damien committed
442
                        assert(exc_sp >= &exc_stack[0]);
443
                        assert(currently_in_except_block);
444
                        //sp = (mp_obj_t*)(*exc_sp--);
Damien's avatar
Damien committed
445
                        //exc_sp--; // discard ip
446
447
                        currently_in_except_block = (exc_sp->val_sp & 1); // restore previous state
                        exc_sp--; // pop back to previous exception handler
448
                        //sp -= 3; // pop 3 exception values
449
450
                        break;

451
452
453
454
455
456
457
458
                    case MP_BC_NOT:
                        if (TOP() == mp_const_true) {
                            SET_TOP(mp_const_false);
                        } else {
                            SET_TOP(mp_const_true);
                        }
                        break;

459
                    case MP_BC_UNARY_OP:
Damien's avatar
Damien committed
460
                        unum = *ip++;
461
                        SET_TOP(rt_unary_op(unum, TOP()));
Damien's avatar
Damien committed
462
463
                        break;

464
                    case MP_BC_BINARY_OP:
465
466
                        unum = *ip++;
                        obj2 = POP();
467
468
                        obj1 = TOP();
                        SET_TOP(rt_binary_op(unum, obj1, obj2));
469
470
                        break;

471
                    case MP_BC_BUILD_TUPLE:
472
                        DECODE_UINT;
473
474
                        sp -= unum - 1;
                        SET_TOP(rt_build_tuple(unum, sp));
475
476
                        break;

477
                    case MP_BC_BUILD_LIST:
478
                        DECODE_UINT;
479
480
                        sp -= unum - 1;
                        SET_TOP(rt_build_list(unum, sp));
481
482
                        break;

483
                    case MP_BC_LIST_APPEND:
484
485
                        DECODE_UINT;
                        // I think it's guaranteed by the compiler that sp[unum] is a list
486
487
                        rt_list_append(sp[-unum], sp[0]);
                        sp--;
488
489
                        break;

490
                    case MP_BC_BUILD_MAP:
491
492
493
494
                        DECODE_UINT;
                        PUSH(rt_build_map(unum));
                        break;

495
                    case MP_BC_STORE_MAP:
496
497
                        sp -= 2;
                        rt_store_map(sp[0], sp[2], sp[1]);
498
499
                        break;

500
                    case MP_BC_MAP_ADD:
Damien's avatar
Damien committed
501
                        DECODE_UINT;
502
503
504
                        // 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;
Damien's avatar
Damien committed
505
506
                        break;

507
                    case MP_BC_BUILD_SET:
508
                        DECODE_UINT;
509
510
                        sp -= unum - 1;
                        SET_TOP(rt_build_set(unum, sp));
511
512
                        break;

513
                    case MP_BC_SET_ADD:
Damien's avatar
Damien committed
514
                        DECODE_UINT;
515
516
517
                        // I think it's guaranteed by the compiler that sp[-unum] is a set
                        rt_store_set(sp[-unum], sp[0]);
                        sp--;
Damien's avatar
Damien committed
518
519
                        break;

520
#if MICROPY_ENABLE_SLICE
521
522
523
524
525
526
527
528
529
530
531
                    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;
532
#endif
533

534
                    case MP_BC_UNPACK_SEQUENCE:
535
                        DECODE_UINT;
536
                        rt_unpack_sequence(sp[0], unum, sp);
537
                        sp += unum - 1;
538
539
                        break;

540
                    case MP_BC_MAKE_FUNCTION:
541
                        DECODE_UINT;
542
543
544
545
546
547
                        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()));
548
549
                        break;

550
                    case MP_BC_MAKE_CLOSURE:
Damien's avatar
Damien committed
551
                        DECODE_UINT;
552
                        SET_TOP(rt_make_closure_from_id(unum, TOP()));
Damien's avatar
Damien committed
553
554
                        break;

555
                    case MP_BC_CALL_FUNCTION:
556
                        DECODE_UINT;
557
558
559
560
                        // 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));
561
562
                        break;

563
                    case MP_BC_CALL_METHOD:
564
                        DECODE_UINT;
565
566
567
568
                        // 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));
569
570
                        break;

571
                    case MP_BC_RETURN_VALUE:
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
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--;
                        }
589
                        nlr_pop();
590
                        *sp_in_out = sp;
591
                        assert(exc_sp == &exc_stack[0] - 1);
592
                        return MP_VM_RETURN_NORMAL;
593

594
595
596
597
                    case MP_BC_RAISE_VARARGS:
                        unum = *ip++;
                        assert(unum == 1);
                        obj1 = POP();
598
                        nlr_jump(rt_make_raise_obj(obj1));
599

600
                    case MP_BC_YIELD_VALUE:
601
602
603
                        nlr_pop();
                        *ip_in_out = ip;
                        *sp_in_out = sp;
604
                        return MP_VM_RETURN_YIELD;
605

606
                    case MP_BC_IMPORT_NAME:
607
608
                        DECODE_QSTR;
                        obj1 = POP();
609
                        SET_TOP(rt_import_name(qst, obj1, TOP()));
610
611
                        break;

612
                    case MP_BC_IMPORT_FROM:
613
                        DECODE_QSTR;
614
                        obj1 = rt_import_from(TOP(), qst);
615
616
617
                        PUSH(obj1);
                        break;

618
                    case MP_BC_IMPORT_STAR:
619
                        rt_import_all(POP());
620
621
                        break;

622
                    default:
Damien's avatar
Damien committed
623
                        printf("code %p, byte code 0x%02x not implemented\n", ip, op);
624
625
                        assert(0);
                        nlr_pop();
626
                        return MP_VM_RETURN_NORMAL;
Damien's avatar
Damien committed
627
                }
628
629
630
631
632
            }

        } else {
            // exception occurred

633
            // set file and line number that the exception occurred at
634
635
            // TODO: don't set traceback for exceptions re-raised by END_FINALLY.
            // But consider how to handle nested exceptions.
636
            if (mp_obj_is_exception_instance(nlr.ret_val)) {
637
                machine_uint_t code_info_size = code_info[0] | (code_info[1] << 8) | (code_info[2] << 16) | (code_info[3] << 24);
638
639
                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);
640
641
                machine_uint_t source_line = 1;
                machine_uint_t bc = save_ip - code_info - code_info_size;
642
                //printf("find %lu %d %d\n", bc, code_info[12], code_info[13]);
643
644
645
                for (const byte* ci = code_info + 12; *ci && bc >= ((*ci) & 31); ci++) {
                    bc -= *ci & 31;
                    source_line += *ci >> 5;
646
                }
647
                mp_obj_exception_add_traceback(nlr.ret_val, source_file, source_line, block_name);
648
649
            }

650
651
652
653
654
655
656
657
658
            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
659
660
                currently_in_except_block = (exc_sp->val_sp & 1); // restore previous state
                exc_sp--; // pop back to previous exception handler
661
662
            }

Damien's avatar
Damien committed
663
            if (exc_sp >= &exc_stack[0]) {
664
665
666
                // set flag to indicate that we are now handling an exception
                currently_in_except_block = 1;

667
                // catch exception and pass to byte code
668
669
                sp = (mp_obj_t*)(exc_sp->val_sp & (~((machine_uint_t)1)));
                ip = exc_sp->handler;
Damien's avatar
Damien committed
670
                // push(traceback, exc-val, exc-type)
671
                PUSH(mp_const_none);
Damien's avatar
Damien committed
672
                PUSH(nlr.ret_val);
673
                PUSH(nlr.ret_val); // TODO should be type(nlr.ret_val), I think...
674

675
            } else {
676
677
678
679
                // 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;
680
            }
Damien's avatar
Damien committed
681
682
683
        }
    }
}