{{ message }}
-
-
Notifications
You must be signed in to change notification settings - Fork 35.4k
Expand file tree
/
Copy pathassemble.c
More file actions
600 lines (530 loc) · 18.1 KB
/
Copy pathassemble.c
File metadata and controls
600 lines (530 loc) · 18.1 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
#include "Python.h"
#include "pycore_code.h" // write_location_entry_start()
#include "pycore_compile.h"
#include "pycore_opcode.h" // _PyOpcode_Caches[] and opcode category macros
#include "pycore_pymem.h" // _PyMem_IsPtrFreed()
#include <stdbool.h>
#define DEFAULT_CODE_SIZE 128
#define DEFAULT_LNOTAB_SIZE 16
#define DEFAULT_CNOTAB_SIZE 32
#undef SUCCESS
#undef ERROR
#define SUCCESS 0
#define ERROR -1
#define RETURN_IF_ERROR(X) \
if ((X) == -1) { \
return ERROR; \
}
typedef _PyCompilerSrcLocation location;
typedef _PyCompile_Instruction instruction;
typedef _PyCompile_InstructionSequence instr_sequence;
static inline bool
same_location(location a, location b)
{
return a.lineno == b.lineno &&
a.end_lineno == b.end_lineno &&
a.col_offset == b.col_offset &&
a.end_col_offset == b.end_col_offset;
}
struct assembler {
PyObject *a_bytecode; /* bytes containing bytecode */
int a_offset; /* offset into bytecode */
PyObject *a_except_table; /* bytes containing exception table */
int a_except_table_off; /* offset into exception table */
/* Location Info */
int a_lineno; /* lineno of last emitted instruction */
PyObject* a_linetable; /* bytes containing location info */
int a_location_off; /* offset of last written location info frame */
};
static int
assemble_init(struct assembler *a, int firstlineno)
{
memset(a, 0, sizeof(struct assembler));
a->a_lineno = firstlineno;
a->a_linetable = NULL;
a->a_location_off = 0;
a->a_except_table = NULL;
a->a_bytecode = PyBytes_FromStringAndSize(NULL, DEFAULT_CODE_SIZE);
if (a->a_bytecode == NULL) {
goto error;
}
a->a_linetable = PyBytes_FromStringAndSize(NULL, DEFAULT_CNOTAB_SIZE);
if (a->a_linetable == NULL) {
goto error;
}
a->a_except_table = PyBytes_FromStringAndSize(NULL, DEFAULT_LNOTAB_SIZE);
if (a->a_except_table == NULL) {
goto error;
}
return SUCCESS;
error:
Py_XDECREF(a->a_bytecode);
Py_XDECREF(a->a_linetable);
Py_XDECREF(a->a_except_table);
return ERROR;
}
static void
assemble_free(struct assembler *a)
{
Py_XDECREF(a->a_bytecode);
Py_XDECREF(a->a_linetable);
Py_XDECREF(a->a_except_table);
}
static inline void
write_except_byte(struct assembler *a, int byte) {
unsigned char *p = (unsigned char *) PyBytes_AS_STRING(a->a_except_table);
p[a->a_except_table_off++] = byte;
}
#define CONTINUATION_BIT 64
static void
assemble_emit_exception_table_item(struct assembler *a, int value, int msb)
{
assert ((msb | 128) == 128);
assert(value >= 0 && value < (1 << 30));
if (value >= 1 << 24) {
write_except_byte(a, (value >> 24) | CONTINUATION_BIT | msb);
msb = 0;
}
if (value >= 1 << 18) {
write_except_byte(a, ((value >> 18)&0x3f) | CONTINUATION_BIT | msb);
msb = 0;
}
if (value >= 1 << 12) {
write_except_byte(a, ((value >> 12)&0x3f) | CONTINUATION_BIT | msb);
msb = 0;
}
if (value >= 1 << 6) {
write_except_byte(a, ((value >> 6)&0x3f) | CONTINUATION_BIT | msb);
msb = 0;
}
write_except_byte(a, (value&0x3f) | msb);
}
/* See Objects/exception_handling_notes.txt for details of layout */
#define MAX_SIZE_OF_ENTRY 20
static int
assemble_emit_exception_table_entry(struct assembler *a, int start, int end,
_PyCompile_ExceptHandlerInfo *handler)
{
Py_ssize_t len = PyBytes_GET_SIZE(a->a_except_table);
if (a->a_except_table_off + MAX_SIZE_OF_ENTRY >= len) {
RETURN_IF_ERROR(_PyBytes_Resize(&a->a_except_table, len * 2));
}
int size = end-start;
assert(end > start);
int target = handler->h_offset;
int depth = handler->h_startdepth - 1;
if (handler->h_preserve_lasti > 0) {
depth -= 1;
}
assert(depth >= 0);
int depth_lasti = (depth<<1) | handler->h_preserve_lasti;
assemble_emit_exception_table_item(a, start, (1<<7));
assemble_emit_exception_table_item(a, size, 0);
assemble_emit_exception_table_item(a, target, 0);
assemble_emit_exception_table_item(a, depth_lasti, 0);
return SUCCESS;
}
static int
assemble_exception_table(struct assembler *a, instr_sequence *instrs)
{
int ioffset = 0;
_PyCompile_ExceptHandlerInfo handler;
handler.h_offset = -1;
handler.h_preserve_lasti = -1;
int start = -1;
for (int i = 0; i < instrs->s_used; i++) {
instruction *instr = &instrs->s_instrs[i];
if (instr->i_except_handler_info.h_offset != handler.h_offset) {
if (handler.h_offset >= 0) {
RETURN_IF_ERROR(
assemble_emit_exception_table_entry(a, start, ioffset, &handler));
}
start = ioffset;
handler = instr->i_except_handler_info;
}
ioffset += _PyCompile_InstrSize(instr->i_opcode, instr->i_oparg);
}
if (handler.h_offset >= 0) {
RETURN_IF_ERROR(assemble_emit_exception_table_entry(a, start, ioffset, &handler));
}
return SUCCESS;
}
/* Code location emitting code. See locations.md for a description of the format. */
#define MSB 0x80
static void
write_location_byte(struct assembler* a, int val)
{
PyBytes_AS_STRING(a->a_linetable)[a->a_location_off] = val&255;
a->a_location_off++;
}
static uint8_t *
location_pointer(struct assembler* a)
{
return (uint8_t *)PyBytes_AS_STRING(a->a_linetable) +
a->a_location_off;
}
static void
write_location_first_byte(struct assembler* a, int code, int length)
{
a->a_location_off += write_location_entry_start(
location_pointer(a), code, length);
}
static void
write_location_varint(struct assembler* a, unsigned int val)
{
uint8_t *ptr = location_pointer(a);
a->a_location_off += write_varint(ptr, val);
}
static void
write_location_signed_varint(struct assembler* a, int val)
{
uint8_t *ptr = location_pointer(a);
a->a_location_off += write_signed_varint(ptr, val);
}
static void
write_location_info_short_form(struct assembler* a, int length, int column, int end_column)
{
assert(length > 0 && length <= 8);
int column_low_bits = column & 7;
int column_group = column >> 3;
assert(column < 80);
assert(end_column >= column);
assert(end_column - column < 16);
write_location_first_byte(a, PY_CODE_LOCATION_INFO_SHORT0 + column_group, length);
write_location_byte(a, (column_low_bits << 4) | (end_column - column));
}
static void
write_location_info_oneline_form(struct assembler* a, int length, int line_delta, int column, int end_column)
{
assert(length > 0 && length <= 8);
assert(line_delta >= 0 && line_delta < 3);
assert(column < 128);
assert(end_column < 128);
write_location_first_byte(a, PY_CODE_LOCATION_INFO_ONE_LINE0 + line_delta, length);
write_location_byte(a, column);
write_location_byte(a, end_column);
}
static void
write_location_info_long_form(struct assembler* a, location loc, int length)
{
assert(length > 0 && length <= 8);
write_location_first_byte(a, PY_CODE_LOCATION_INFO_LONG, length);
write_location_signed_varint(a, loc.lineno - a->a_lineno);
assert(loc.end_lineno >= loc.lineno);
write_location_varint(a, loc.end_lineno - loc.lineno);
write_location_varint(a, loc.col_offset + 1);
write_location_varint(a, loc.end_col_offset + 1);
}
static void
write_location_info_none(struct assembler* a, int length)
{
write_location_first_byte(a, PY_CODE_LOCATION_INFO_NONE, length);
}
static void
write_location_info_no_column(struct assembler* a, int length, int line_delta)
{
write_location_first_byte(a, PY_CODE_LOCATION_INFO_NO_COLUMNS, length);
write_location_signed_varint(a, line_delta);
}
#define THEORETICAL_MAX_ENTRY_SIZE 25 /* 1 + 6 + 6 + 6 + 6 */
static int
write_location_info_entry(struct assembler* a, location loc, int isize)
{
Py_ssize_t len = PyBytes_GET_SIZE(a->a_linetable);
if (a->a_location_off + THEORETICAL_MAX_ENTRY_SIZE >= len) {
assert(len > THEORETICAL_MAX_ENTRY_SIZE);
RETURN_IF_ERROR(_PyBytes_Resize(&a->a_linetable, len*2));
}
if (loc.lineno == NO_LOCATION.lineno) {
write_location_info_none(a, isize);
return SUCCESS;
}
int line_delta = loc.lineno - a->a_lineno;
int column = loc.col_offset;
int end_column = loc.end_col_offset;
if (column < 0 || end_column < 0) {
if (loc.end_lineno == loc.lineno || loc.end_lineno < 0) {
write_location_info_no_column(a, isize, line_delta);
a->a_lineno = loc.lineno;
return SUCCESS;
}
}
else if (loc.end_lineno == loc.lineno) {
if (line_delta == 0 && column < 80 && end_column - column < 16 && end_column >= column) {
write_location_info_short_form(a, isize, column, end_column);
return SUCCESS;
}
if (line_delta >= 0 && line_delta < 3 && column < 128 && end_column < 128) {
write_location_info_oneline_form(a, isize, line_delta, column, end_column);
a->a_lineno = loc.lineno;
return SUCCESS;
}
}
write_location_info_long_form(a, loc, isize);
a->a_lineno = loc.lineno;
return SUCCESS;
}
static int
assemble_emit_location(struct assembler* a, location loc, int isize)
{
if (isize == 0) {
return SUCCESS;
}
while (isize > 8) {
RETURN_IF_ERROR(write_location_info_entry(a, loc, 8));
isize -= 8;
}
return write_location_info_entry(a, loc, isize);
}
static int
assemble_location_info(struct assembler *a, instr_sequence *instrs,
int firstlineno)
{
a->a_lineno = firstlineno;
location loc = NO_LOCATION;
int size = 0;
for (int i = 0; i < instrs->s_used; i++) {
instruction *instr = &instrs->s_instrs[i];
if (!same_location(loc, instr->i_loc)) {
RETURN_IF_ERROR(assemble_emit_location(a, loc, size));
loc = instr->i_loc;
size = 0;
}
size += _PyCompile_InstrSize(instr->i_opcode, instr->i_oparg);
}
RETURN_IF_ERROR(assemble_emit_location(a, loc, size));
return SUCCESS;
}
static void
write_instr(_Py_CODEUNIT *codestr, instruction *instr, int ilen)
{
int opcode = instr->i_opcode;
assert(!IS_PSEUDO_OPCODE(opcode));
int oparg = instr->i_oparg;
assert(HAS_ARG(opcode) || oparg == 0);
int caches = _PyOpcode_Caches[opcode];
switch (ilen - caches) {
case 4:
codestr->op.code = EXTENDED_ARG;
codestr->op.arg = (oparg >> 24) & 0xFF;
codestr++;
/* fall through */
case 3:
codestr->op.code = EXTENDED_ARG;
codestr->op.arg = (oparg >> 16) & 0xFF;
codestr++;
/* fall through */
case 2:
codestr->op.code = EXTENDED_ARG;
codestr->op.arg = (oparg >> 8) & 0xFF;
codestr++;
/* fall through */
case 1:
codestr->op.code = opcode;
codestr->op.arg = oparg & 0xFF;
codestr++;
break;
default:
Py_UNREACHABLE();
}
while (caches--) {
codestr->op.code = CACHE;
codestr->op.arg = 0;
codestr++;
}
}
/* assemble_emit_instr()
Extend the bytecode with a new instruction.
Update lnotab if necessary.
*/
static int
assemble_emit_instr(struct assembler *a, instruction *instr)
{
Py_ssize_t len = PyBytes_GET_SIZE(a->a_bytecode);
_Py_CODEUNIT *code;
int size = _PyCompile_InstrSize(instr->i_opcode, instr->i_oparg);
if (a->a_offset + size >= len / (int)sizeof(_Py_CODEUNIT)) {
if (len > PY_SSIZE_T_MAX / 2) {
return ERROR;
}
RETURN_IF_ERROR(_PyBytes_Resize(&a->a_bytecode, len * 2));
}
code = (_Py_CODEUNIT *)PyBytes_AS_STRING(a->a_bytecode) + a->a_offset;
a->a_offset += size;
write_instr(code, instr, size);
return SUCCESS;
}
static int
assemble_emit(struct assembler *a, instr_sequence *instrs,
int first_lineno, PyObject *const_cache)
{
RETURN_IF_ERROR(assemble_init(a, first_lineno));
for (int i = 0; i < instrs->s_used; i++) {
instruction *instr = &instrs->s_instrs[i];
RETURN_IF_ERROR(assemble_emit_instr(a, instr));
}
RETURN_IF_ERROR(assemble_location_info(a, instrs, a->a_lineno));
RETURN_IF_ERROR(assemble_exception_table(a, instrs));
RETURN_IF_ERROR(_PyBytes_Resize(&a->a_except_table, a->a_except_table_off));
RETURN_IF_ERROR(_PyCompile_ConstCacheMergeOne(const_cache, &a->a_except_table));
RETURN_IF_ERROR(_PyBytes_Resize(&a->a_linetable, a->a_location_off));
RETURN_IF_ERROR(_PyCompile_ConstCacheMergeOne(const_cache, &a->a_linetable));
RETURN_IF_ERROR(_PyBytes_Resize(&a->a_bytecode, a->a_offset * sizeof(_Py_CODEUNIT)));
RETURN_IF_ERROR(_PyCompile_ConstCacheMergeOne(const_cache, &a->a_bytecode));
return SUCCESS;
}
static PyObject *
dict_keys_inorder(PyObject *dict, Py_ssize_t offset)
{
PyObject *tuple, *k, *v;
Py_ssize_t i, pos = 0, size = PyDict_GET_SIZE(dict);
tuple = PyTuple_New(size);
if (tuple == NULL)
return NULL;
while (PyDict_Next(dict, &pos, &k, &v)) {
i = PyLong_AS_LONG(v);
assert((i - offset) < size);
assert((i - offset) >= 0);
PyTuple_SET_ITEM(tuple, i - offset, Py_NewRef(k));
}
return tuple;
}
// This is in codeobject.c.
extern void _Py_set_localsplus_info(int, PyObject *, unsigned char,
PyObject *, PyObject *);
static void
compute_localsplus_info(_PyCompile_CodeUnitMetadata *umd, int nlocalsplus,
PyObject *names, PyObject *kinds)
{
PyObject *k, *v;
Py_ssize_t pos = 0;
while (PyDict_Next(umd->u_varnames, &pos, &k, &v)) {
int offset = (int)PyLong_AS_LONG(v);
assert(offset >= 0);
assert(offset < nlocalsplus);
// For now we do not distinguish arg kinds.
_PyLocals_Kind kind = CO_FAST_LOCAL;
if (PyDict_Contains(umd->u_fasthidden, k)) {
kind |= CO_FAST_HIDDEN;
}
if (PyDict_GetItem(umd->u_cellvars, k) != NULL) {
kind |= CO_FAST_CELL;
}
_Py_set_localsplus_info(offset, k, kind, names, kinds);
}
int nlocals = (int)PyDict_GET_SIZE(umd->u_varnames);
// This counter mirrors the fix done in fix_cell_offsets().
int numdropped = 0;
pos = 0;
while (PyDict_Next(umd->u_cellvars, &pos, &k, &v)) {
if (PyDict_GetItem(umd->u_varnames, k) != NULL) {
// Skip cells that are already covered by locals.
numdropped += 1;
continue;
}
int offset = (int)PyLong_AS_LONG(v);
assert(offset >= 0);
offset += nlocals - numdropped;
assert(offset < nlocalsplus);
_Py_set_localsplus_info(offset, k, CO_FAST_CELL, names, kinds);
}
pos = 0;
while (PyDict_Next(umd->u_freevars, &pos, &k, &v)) {
int offset = (int)PyLong_AS_LONG(v);
assert(offset >= 0);
offset += nlocals - numdropped;
assert(offset < nlocalsplus);
_Py_set_localsplus_info(offset, k, CO_FAST_FREE, names, kinds);
}
}
static PyCodeObject *
makecode(_PyCompile_CodeUnitMetadata *umd, struct assembler *a, PyObject *const_cache,
PyObject *constslist, int maxdepth, int nlocalsplus, int code_flags,
PyObject *filename)
{
PyCodeObject *co = NULL;
PyObject *names = NULL;
PyObject *consts = NULL;
PyObject *localsplusnames = NULL;
PyObject *localspluskinds = NULL;
names = dict_keys_inorder(umd->u_names, 0);
if (!names) {
goto error;
}
if (_PyCompile_ConstCacheMergeOne(const_cache, &names) < 0) {
goto error;
}
consts = PyList_AsTuple(constslist); /* PyCode_New requires a tuple */
if (consts == NULL) {
goto error;
}
if (_PyCompile_ConstCacheMergeOne(const_cache, &consts) < 0) {
goto error;
}
assert(umd->u_posonlyargcount < INT_MAX);
assert(umd->u_argcount < INT_MAX);
assert(umd->u_kwonlyargcount < INT_MAX);
int posonlyargcount = (int)umd->u_posonlyargcount;
int posorkwargcount = (int)umd->u_argcount;
assert(INT_MAX - posonlyargcount - posorkwargcount > 0);
int kwonlyargcount = (int)umd->u_kwonlyargcount;
localsplusnames = PyTuple_New(nlocalsplus);
if (localsplusnames == NULL) {
goto error;
}
localspluskinds = PyBytes_FromStringAndSize(NULL, nlocalsplus);
if (localspluskinds == NULL) {
goto error;
}
compute_localsplus_info(umd, nlocalsplus, localsplusnames, localspluskinds);
struct _PyCodeConstructor con = {
.filename = filename,
.name = umd->u_name,
.qualname = umd->u_qualname ? umd->u_qualname : umd->u_name,
.flags = code_flags,
.code = a->a_bytecode,
.firstlineno = umd->u_firstlineno,
.linetable = a->a_linetable,
.consts = consts,
.names = names,
.localsplusnames = localsplusnames,
.localspluskinds = localspluskinds,
.argcount = posonlyargcount + posorkwargcount,
.posonlyargcount = posonlyargcount,
.kwonlyargcount = kwonlyargcount,
.stacksize = maxdepth,
.exceptiontable = a->a_except_table,
};
if (_PyCode_Validate(&con) < 0) {
goto error;
}
if (_PyCompile_ConstCacheMergeOne(const_cache, &localsplusnames) < 0) {
goto error;
}
con.localsplusnames = localsplusnames;
co = _PyCode_New(&con);
if (co == NULL) {
goto error;
}
error:
Py_XDECREF(names);
Py_XDECREF(consts);
Py_XDECREF(localsplusnames);
Py_XDECREF(localspluskinds);
return co;
}
PyCodeObject *
_PyAssemble_MakeCodeObject(_PyCompile_CodeUnitMetadata *umd, PyObject *const_cache,
PyObject *consts, int maxdepth, instr_sequence *instrs,
int nlocalsplus, int code_flags, PyObject *filename)
{
PyCodeObject *co = NULL;
struct assembler a;
int res = assemble_emit(&a, instrs, umd->u_firstlineno, const_cache);
if (res == SUCCESS) {
co = makecode(umd, &a, const_cache, consts, maxdepth, nlocalsplus,
code_flags, filename);
}
assemble_free(&a);
return co;
}
You can’t perform that action at this time.