-
Notifications
You must be signed in to change notification settings - Fork 7.8k
/
Copy pathsccp.c
2578 lines (2357 loc) · 72 KB
/
sccp.c
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
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
+----------------------------------------------------------------------+
| Zend Engine, SCCP - Sparse Conditional Constant Propagation |
+----------------------------------------------------------------------+
| Copyright (c) The PHP Group |
+----------------------------------------------------------------------+
| This source file is subject to version 3.01 of the PHP license, |
| that is bundled with this package in the file LICENSE, and is |
| available through the world-wide-web at the following url: |
| https://www.php.net/license/3_01.txt |
| If you did not receive a copy of the PHP license and are unable to |
| obtain it through the world-wide-web, please send a note to |
| license@php.net so we can mail you a copy immediately. |
+----------------------------------------------------------------------+
| Authors: Nikita Popov <nikic@php.net> |
| Dmitry Stogov <dmitry@php.net> |
+----------------------------------------------------------------------+
*/
#include "php.h"
#include "zend_API.h"
#include "zend_exceptions.h"
#include "zend_ini.h"
#include "zend_type_info.h"
#include "Optimizer/zend_optimizer_internal.h"
#include "Optimizer/zend_call_graph.h"
#include "Optimizer/zend_inference.h"
#include "Optimizer/scdf.h"
#include "Optimizer/zend_dump.h"
/* This implements sparse conditional constant propagation (SCCP) based on the SCDF framework. The
* used value lattice is defined as follows:
*
* BOT < {constant values} < TOP
*
* TOP indicates an underdefined value, i.e. that we do not yet know the value of variable.
* BOT indicates an overdefined value, i.e. that we know the variable to be non-constant.
*
* All variables are optimistically initialized to TOP, apart from the implicit variables defined
* at the start of the first block. Note that variables that MAY_BE_REF are *not* initialized to
* BOT. We rely on the fact that any operation resulting in a reference will produce a BOT anyway.
* This is better because such operations might never be reached due to the conditional nature of
* the algorithm.
*
* The meet operation for phi functions is defined as follows:
* BOT + any = BOT
* TOP + any = any
* C_i + C_i = C_i (i.e. two equal constants)
* C_i + C_j = BOT (i.e. two different constants)
*
* When evaluating instructions TOP and BOT are handled as follows:
* a) If any operand is BOT, the result is BOT. The main exception to this is op1 of ASSIGN, which
* is ignored. However, if the op1 MAY_BE_REF we do have to propagate the BOT.
* b) Otherwise, if the instruction can never be evaluated (either in general, or with the
* specific modifiers) the result is BOT.
* c) Otherwise, if any operand is TOP, the result is TOP.
* d) Otherwise (at this point all operands are known and constant), if we can compute the result
* for these specific constants (without throwing notices or similar) then that is the result.
* e) Otherwise the result is BOT.
*
* It is sometimes possible to determine a result even if one argument is TOP / BOT, e.g. for things
* like BOT*0. Right now we don't bother with this -- the only thing that is done is evaluating
* TYPE_CHECKS based on the type information.
*
* Feasible successors for conditional branches are determined as follows:
* a) If we don't support the branch type or branch on BOT, all successors are feasible.
* b) Otherwise, if we branch on TOP none of the successors are feasible.
* c) Otherwise (we branch on a constant), the feasible successors are marked based on the constant
* (usually only one successor will be feasible).
*
* The original SCCP algorithm is extended with ability to propagate constant array
* elements and object properties. The extension is based on a variation of Array
* SSA form and its application to Spare Constant Propagation, described at
* "Array SSA Form" by Vivek Sarkar, Kathleen Knobe and Stephen Fink in chapter
* 16 of the SSA book.
*/
#define SCP_DEBUG 0
typedef struct _sccp_ctx {
scdf_ctx scdf;
zend_call_info **call_map;
zval *values;
zval top;
zval bot;
} sccp_ctx;
#define TOP ((zend_uchar)-1)
#define BOT ((zend_uchar)-2)
#define PARTIAL_ARRAY ((zend_uchar)-3)
#define PARTIAL_OBJECT ((zend_uchar)-4)
#define IS_TOP(zv) (Z_TYPE_P(zv) == TOP)
#define IS_BOT(zv) (Z_TYPE_P(zv) == BOT)
#define IS_PARTIAL_ARRAY(zv) (Z_TYPE_P(zv) == PARTIAL_ARRAY)
#define IS_PARTIAL_OBJECT(zv) (Z_TYPE_P(zv) == PARTIAL_OBJECT)
#define MAKE_PARTIAL_ARRAY(zv) (Z_TYPE_INFO_P(zv) = PARTIAL_ARRAY | (IS_TYPE_REFCOUNTED << Z_TYPE_FLAGS_SHIFT))
#define MAKE_PARTIAL_OBJECT(zv) (Z_TYPE_INFO_P(zv) = PARTIAL_OBJECT | (IS_TYPE_REFCOUNTED << Z_TYPE_FLAGS_SHIFT))
#define MAKE_TOP(zv) (Z_TYPE_INFO_P(zv) = TOP)
#define MAKE_BOT(zv) (Z_TYPE_INFO_P(zv) = BOT)
static void scp_dump_value(zval *zv) {
if (IS_TOP(zv)) {
fprintf(stderr, " top");
} else if (IS_BOT(zv)) {
fprintf(stderr, " bot");
} else if (Z_TYPE_P(zv) == IS_ARRAY || IS_PARTIAL_ARRAY(zv)) {
fprintf(stderr, " %s[", IS_PARTIAL_ARRAY(zv) ? "partial " : "");
zend_dump_ht(Z_ARRVAL_P(zv));
fprintf(stderr, "]");
} else if (IS_PARTIAL_OBJECT(zv)) {
fprintf(stderr, " {");
zend_dump_ht(Z_ARRVAL_P(zv));
fprintf(stderr, "}");
} else {
zend_dump_const(zv);
}
}
static void empty_partial_array(zval *zv)
{
MAKE_PARTIAL_ARRAY(zv);
Z_ARR_P(zv) = zend_new_array(8);
}
static void dup_partial_array(zval *dst, zval *src)
{
MAKE_PARTIAL_ARRAY(dst);
Z_ARR_P(dst) = zend_array_dup(Z_ARR_P(src));
}
static void empty_partial_object(zval *zv)
{
MAKE_PARTIAL_OBJECT(zv);
Z_ARR_P(zv) = zend_new_array(8);
}
static void dup_partial_object(zval *dst, zval *src)
{
MAKE_PARTIAL_OBJECT(dst);
Z_ARR_P(dst) = zend_array_dup(Z_ARR_P(src));
}
static inline bool value_known(zval *zv) {
return !IS_TOP(zv) && !IS_BOT(zv);
}
/* Sets new value for variable and ensures that it is lower or equal
* the previous one in the constant propagation lattice. */
static void set_value(scdf_ctx *scdf, sccp_ctx *ctx, int var, zval *new) {
zval *value = &ctx->values[var];
if (IS_BOT(value) || IS_TOP(new)) {
return;
}
#if SCP_DEBUG
fprintf(stderr, "Lowering #%d.", var);
zend_dump_var(scdf->op_array, IS_CV, scdf->ssa->vars[var].var);
fprintf(stderr, " from");
scp_dump_value(value);
fprintf(stderr, " to");
scp_dump_value(new);
fprintf(stderr, "\n");
#endif
if (IS_TOP(value) || IS_BOT(new)) {
zval_ptr_dtor_nogc(value);
ZVAL_COPY(value, new);
scdf_add_to_worklist(scdf, var);
return;
}
/* Always replace PARTIAL_(ARRAY|OBJECT), as new maybe changed by join_partial_(arrays|object) */
if (IS_PARTIAL_ARRAY(new) || IS_PARTIAL_OBJECT(new)) {
if (Z_TYPE_P(value) != Z_TYPE_P(new)
|| zend_hash_num_elements(Z_ARR_P(new)) != zend_hash_num_elements(Z_ARR_P(value))) {
zval_ptr_dtor_nogc(value);
ZVAL_COPY(value, new);
scdf_add_to_worklist(scdf, var);
}
return;
}
#if ZEND_DEBUG
ZEND_ASSERT(zend_is_identical(value, new) ||
(Z_TYPE_P(value) == IS_DOUBLE && Z_TYPE_P(new) == IS_DOUBLE && isnan(Z_DVAL_P(value)) && isnan(Z_DVAL_P(new))));
#endif
}
static zval *get_op1_value(sccp_ctx *ctx, zend_op *opline, zend_ssa_op *ssa_op) {
if (opline->op1_type == IS_CONST) {
return CT_CONSTANT_EX(ctx->scdf.op_array, opline->op1.constant);
} else if (ssa_op->op1_use != -1) {
return &ctx->values[ssa_op->op1_use];
} else {
return NULL;
}
}
static zval *get_op2_value(sccp_ctx *ctx, zend_op *opline, zend_ssa_op *ssa_op) {
if (opline->op2_type == IS_CONST) {
return CT_CONSTANT_EX(ctx->scdf.op_array, opline->op2.constant);
} else if (ssa_op->op2_use != -1) {
return &ctx->values[ssa_op->op2_use];
} else {
return NULL;
}
}
static bool can_replace_op1(
const zend_op_array *op_array, zend_op *opline, zend_ssa_op *ssa_op) {
switch (opline->opcode) {
case ZEND_PRE_INC:
case ZEND_PRE_DEC:
case ZEND_PRE_INC_OBJ:
case ZEND_PRE_DEC_OBJ:
case ZEND_POST_INC:
case ZEND_POST_DEC:
case ZEND_POST_INC_OBJ:
case ZEND_POST_DEC_OBJ:
case ZEND_ASSIGN:
case ZEND_ASSIGN_REF:
case ZEND_ASSIGN_DIM:
case ZEND_ASSIGN_OBJ:
case ZEND_ASSIGN_OBJ_REF:
case ZEND_ASSIGN_OP:
case ZEND_ASSIGN_DIM_OP:
case ZEND_ASSIGN_OBJ_OP:
case ZEND_ASSIGN_STATIC_PROP_OP:
case ZEND_FETCH_DIM_W:
case ZEND_FETCH_DIM_RW:
case ZEND_FETCH_DIM_UNSET:
case ZEND_FETCH_DIM_FUNC_ARG:
case ZEND_FETCH_OBJ_W:
case ZEND_FETCH_OBJ_RW:
case ZEND_FETCH_OBJ_UNSET:
case ZEND_FETCH_OBJ_FUNC_ARG:
case ZEND_FETCH_LIST_W:
case ZEND_UNSET_DIM:
case ZEND_UNSET_OBJ:
case ZEND_SEND_REF:
case ZEND_SEND_VAR_EX:
case ZEND_SEND_FUNC_ARG:
case ZEND_SEND_UNPACK:
case ZEND_SEND_ARRAY:
case ZEND_SEND_USER:
case ZEND_FE_RESET_RW:
return 0;
/* Do not accept CONST */
case ZEND_ROPE_ADD:
case ZEND_ROPE_END:
case ZEND_BIND_STATIC:
case ZEND_BIND_GLOBAL:
case ZEND_MAKE_REF:
case ZEND_UNSET_CV:
case ZEND_ISSET_ISEMPTY_CV:
return 0;
case ZEND_INIT_ARRAY:
case ZEND_ADD_ARRAY_ELEMENT:
return !(opline->extended_value & ZEND_ARRAY_ELEMENT_REF);
case ZEND_YIELD:
return !(op_array->fn_flags & ZEND_ACC_RETURN_REFERENCE);
case ZEND_VERIFY_RETURN_TYPE:
// TODO: This would require a non-local change ???
return 0;
case ZEND_OP_DATA:
return (opline - 1)->opcode != ZEND_ASSIGN_OBJ_REF &&
(opline - 1)->opcode != ZEND_ASSIGN_STATIC_PROP_REF;
default:
if (ssa_op->op1_def != -1) {
ZEND_UNREACHABLE();
return 0;
}
}
return 1;
}
static bool can_replace_op2(
const zend_op_array *op_array, zend_op *opline, zend_ssa_op *ssa_op) {
switch (opline->opcode) {
/* Do not accept CONST */
case ZEND_DECLARE_CLASS_DELAYED:
case ZEND_BIND_LEXICAL:
case ZEND_FE_FETCH_R:
case ZEND_FE_FETCH_RW:
return 0;
}
return 1;
}
static bool try_replace_op1(
sccp_ctx *ctx, zend_op *opline, zend_ssa_op *ssa_op, int var, zval *value) {
if (ssa_op->op1_use == var && can_replace_op1(ctx->scdf.op_array, opline, ssa_op)) {
zval zv;
ZVAL_COPY(&zv, value);
if (zend_optimizer_update_op1_const(ctx->scdf.op_array, opline, &zv)) {
return 1;
} else {
// TODO: check the following special cases ???
switch (opline->opcode) {
case ZEND_CASE:
opline->opcode = ZEND_IS_EQUAL;
goto replace_op1_simple;
case ZEND_CASE_STRICT:
opline->opcode = ZEND_IS_IDENTICAL;
goto replace_op1_simple;
case ZEND_FETCH_LIST_R:
case ZEND_SWITCH_STRING:
case ZEND_SWITCH_LONG:
case ZEND_MATCH:
replace_op1_simple:
if (Z_TYPE(zv) == IS_STRING) {
zend_string_hash_val(Z_STR(zv));
}
opline->op1.constant = zend_optimizer_add_literal(ctx->scdf.op_array, &zv);
opline->op1_type = IS_CONST;
return 1;
case ZEND_INSTANCEOF:
zval_ptr_dtor_nogc(&zv);
ZVAL_FALSE(&zv);
opline->opcode = ZEND_QM_ASSIGN;
opline->op1_type = IS_CONST;
opline->op1.constant = zend_optimizer_add_literal(ctx->scdf.op_array, &zv);
opline->op2_type = IS_UNUSED;
if (ssa_op->op2_use >= 0) {
ZEND_ASSERT(ssa_op->op2_def == -1);
zend_ssa_unlink_use_chain(ctx->scdf.ssa, ssa_op - ctx->scdf.ssa->ops, ssa_op->op2_use);
ssa_op->op2_use = -1;
ssa_op->op2_use_chain = -1;
}
return 1;
default:
break;
}
zval_ptr_dtor_nogc(&zv);
}
}
return 0;
}
static bool try_replace_op2(
sccp_ctx *ctx, zend_op *opline, zend_ssa_op *ssa_op, int var, zval *value) {
if (ssa_op->op2_use == var && can_replace_op2(ctx->scdf.op_array, opline, ssa_op)) {
zval zv;
ZVAL_COPY(&zv, value);
if (zend_optimizer_update_op2_const(ctx->scdf.op_array, opline, &zv)) {
return 1;
} else {
switch (opline->opcode) {
case ZEND_FETCH_CLASS:
if (Z_TYPE(zv) == IS_STRING) {
ZEND_ASSERT((opline + 1)->opcode == ZEND_INSTANCEOF);
ZEND_ASSERT(ssa_op->result_def == (ssa_op + 1)->op2_use);
if (zend_optimizer_update_op2_const(ctx->scdf.op_array, opline + 1, &zv)) {
zend_ssa_op *next_op = ssa_op + 1;
zend_ssa_unlink_use_chain(ctx->scdf.ssa, next_op - ctx->scdf.ssa->ops, next_op->op2_use);
next_op->op2_use = -1;
next_op->op2_use_chain = -1;
zend_ssa_remove_result_def(ctx->scdf.ssa, ssa_op);
MAKE_NOP(opline);
return 1;
}
}
default:
break;
}
zval_ptr_dtor_nogc(&zv);
}
}
return 0;
}
static inline int ct_eval_binary_op(zval *result, zend_uchar binop, zval *op1, zval *op2) {
/* TODO: We could implement support for evaluation of + on partial arrays. */
if (IS_PARTIAL_ARRAY(op1) || IS_PARTIAL_ARRAY(op2)) {
return FAILURE;
}
return zend_optimizer_eval_binary_op(result, binop, op1, op2);
}
static inline int ct_eval_bool_cast(zval *result, zval *op) {
if (IS_PARTIAL_ARRAY(op)) {
if (zend_hash_num_elements(Z_ARRVAL_P(op)) == 0) {
/* An empty partial array may be non-empty at runtime, we don't know whether the
* result will be true or false. */
return FAILURE;
}
ZVAL_TRUE(result);
return SUCCESS;
}
ZVAL_BOOL(result, zend_is_true(op));
return SUCCESS;
}
static inline int zval_to_string_offset(zend_long *result, zval *op) {
switch (Z_TYPE_P(op)) {
case IS_LONG:
*result = Z_LVAL_P(op);
return SUCCESS;
case IS_STRING:
if (IS_LONG == is_numeric_string(
Z_STRVAL_P(op), Z_STRLEN_P(op), result, NULL, 0)) {
return SUCCESS;
}
return FAILURE;
default:
return FAILURE;
}
}
static inline int fetch_array_elem(zval **result, zval *op1, zval *op2) {
switch (Z_TYPE_P(op2)) {
case IS_NULL:
*result = zend_hash_find(Z_ARR_P(op1), ZSTR_EMPTY_ALLOC());
return SUCCESS;
case IS_FALSE:
*result = zend_hash_index_find(Z_ARR_P(op1), 0);
return SUCCESS;
case IS_TRUE:
*result = zend_hash_index_find(Z_ARR_P(op1), 1);
return SUCCESS;
case IS_LONG:
*result = zend_hash_index_find(Z_ARR_P(op1), Z_LVAL_P(op2));
return SUCCESS;
case IS_DOUBLE: {
zend_long lval = zend_dval_to_lval(Z_DVAL_P(op2));
if (!zend_is_long_compatible(Z_DVAL_P(op2), lval)) {
return FAILURE;
}
*result = zend_hash_index_find(Z_ARR_P(op1), lval);
return SUCCESS;
}
case IS_STRING:
*result = zend_symtable_find(Z_ARR_P(op1), Z_STR_P(op2));
return SUCCESS;
default:
return FAILURE;
}
}
static inline int ct_eval_fetch_dim(zval *result, zval *op1, zval *op2, int support_strings) {
if (Z_TYPE_P(op1) == IS_ARRAY || IS_PARTIAL_ARRAY(op1)) {
zval *value;
if (fetch_array_elem(&value, op1, op2) == SUCCESS && value && !IS_BOT(value)) {
ZVAL_COPY(result, value);
return SUCCESS;
}
} else if (support_strings && Z_TYPE_P(op1) == IS_STRING) {
zend_long index;
if (zval_to_string_offset(&index, op2) == FAILURE) {
return FAILURE;
}
if (index >= 0 && index < Z_STRLEN_P(op1)) {
ZVAL_STR(result, zend_string_init(&Z_STRVAL_P(op1)[index], 1, 0));
return SUCCESS;
}
}
return FAILURE;
}
/* op1 may be NULL here to indicate an unset value */
static inline int ct_eval_isset_isempty(zval *result, uint32_t extended_value, zval *op1) {
zval zv;
if (!(extended_value & ZEND_ISEMPTY)) {
ZVAL_BOOL(result, op1 && Z_TYPE_P(op1) != IS_NULL);
return SUCCESS;
} else if (!op1) {
ZVAL_TRUE(result);
return SUCCESS;
} else if (ct_eval_bool_cast(&zv, op1) == SUCCESS) {
ZVAL_BOOL(result, Z_TYPE(zv) == IS_FALSE);
return SUCCESS;
} else {
return FAILURE;
}
}
static inline int ct_eval_isset_dim(zval *result, uint32_t extended_value, zval *op1, zval *op2) {
if (Z_TYPE_P(op1) == IS_ARRAY || IS_PARTIAL_ARRAY(op1)) {
zval *value;
if (fetch_array_elem(&value, op1, op2) == FAILURE) {
return FAILURE;
}
if (IS_PARTIAL_ARRAY(op1) && (!value || IS_BOT(value))) {
return FAILURE;
}
return ct_eval_isset_isempty(result, extended_value, value);
} else if (Z_TYPE_P(op1) == IS_STRING) {
// TODO
return FAILURE;
} else {
ZVAL_BOOL(result, (extended_value & ZEND_ISEMPTY));
return SUCCESS;
}
}
static inline int ct_eval_del_array_elem(zval *result, zval *key) {
ZEND_ASSERT(IS_PARTIAL_ARRAY(result));
switch (Z_TYPE_P(key)) {
case IS_NULL:
zend_hash_del(Z_ARR_P(result), ZSTR_EMPTY_ALLOC());
break;
case IS_FALSE:
zend_hash_index_del(Z_ARR_P(result), 0);
break;
case IS_TRUE:
zend_hash_index_del(Z_ARR_P(result), 1);
break;
case IS_LONG:
zend_hash_index_del(Z_ARR_P(result), Z_LVAL_P(key));
break;
case IS_DOUBLE: {
zend_long lval = zend_dval_to_lval(Z_DVAL_P(key));
if (!zend_is_long_compatible(Z_DVAL_P(key), lval)) {
return FAILURE;
}
zend_hash_index_del(Z_ARR_P(result), lval);
break;
}
case IS_STRING:
zend_symtable_del(Z_ARR_P(result), Z_STR_P(key));
break;
default:
return FAILURE;
}
return SUCCESS;
}
static inline int ct_eval_add_array_elem(zval *result, zval *value, zval *key) {
if (!key) {
SEPARATE_ARRAY(result);
if ((value = zend_hash_next_index_insert(Z_ARR_P(result), value))) {
Z_TRY_ADDREF_P(value);
return SUCCESS;
}
return FAILURE;
}
switch (Z_TYPE_P(key)) {
case IS_NULL:
SEPARATE_ARRAY(result);
value = zend_hash_update(Z_ARR_P(result), ZSTR_EMPTY_ALLOC(), value);
break;
case IS_FALSE:
SEPARATE_ARRAY(result);
value = zend_hash_index_update(Z_ARR_P(result), 0, value);
break;
case IS_TRUE:
SEPARATE_ARRAY(result);
value = zend_hash_index_update(Z_ARR_P(result), 1, value);
break;
case IS_LONG:
SEPARATE_ARRAY(result);
value = zend_hash_index_update(Z_ARR_P(result), Z_LVAL_P(key), value);
break;
case IS_DOUBLE: {
zend_long lval = zend_dval_to_lval(Z_DVAL_P(key));
if (!zend_is_long_compatible(Z_DVAL_P(key), lval)) {
return FAILURE;
}
SEPARATE_ARRAY(result);
value = zend_hash_index_update(
Z_ARR_P(result), lval, value);
break;
}
case IS_STRING:
SEPARATE_ARRAY(result);
value = zend_symtable_update(Z_ARR_P(result), Z_STR_P(key), value);
break;
default:
return FAILURE;
}
Z_TRY_ADDREF_P(value);
return SUCCESS;
}
static inline int ct_eval_add_array_unpack(zval *result, zval *array) {
zend_string *key;
zval *value;
if (Z_TYPE_P(array) != IS_ARRAY) {
return FAILURE;
}
SEPARATE_ARRAY(result);
ZEND_HASH_FOREACH_STR_KEY_VAL(Z_ARRVAL_P(array), key, value) {
if (key) {
value = zend_hash_update(Z_ARR_P(result), key, value);
} else {
value = zend_hash_next_index_insert(Z_ARR_P(result), value);
}
if (!value) {
return FAILURE;
}
Z_TRY_ADDREF_P(value);
} ZEND_HASH_FOREACH_END();
return SUCCESS;
}
static inline int ct_eval_assign_dim(zval *result, zval *value, zval *key) {
switch (Z_TYPE_P(result)) {
case IS_NULL:
case IS_FALSE:
array_init(result);
ZEND_FALLTHROUGH;
case IS_ARRAY:
case PARTIAL_ARRAY:
return ct_eval_add_array_elem(result, value, key);
case IS_STRING:
// TODO Before enabling this case, make sure ARRAY_DIM result op is correct
#if 0
zend_long index;
zend_string *new_str, *value_str;
if (!key || Z_TYPE_P(value) == IS_ARRAY
|| zval_to_string_offset(&index, key) == FAILURE || index < 0) {
return FAILURE;
}
if (index >= Z_STRLEN_P(result)) {
new_str = zend_string_alloc(index + 1, 0);
memcpy(ZSTR_VAL(new_str), Z_STRVAL_P(result), Z_STRLEN_P(result));
memset(ZSTR_VAL(new_str) + Z_STRLEN_P(result), ' ', index - Z_STRLEN_P(result));
ZSTR_VAL(new_str)[index + 1] = 0;
} else {
new_str = zend_string_init(Z_STRVAL_P(result), Z_STRLEN_P(result), 0);
}
value_str = zval_get_string(value);
ZVAL_STR(result, new_str);
Z_STRVAL_P(result)[index] = ZSTR_VAL(value_str)[0];
zend_string_release_ex(value_str, 0);
#endif
return FAILURE;
default:
return FAILURE;
}
}
static inline int fetch_obj_prop(zval **result, zval *op1, zval *op2) {
switch (Z_TYPE_P(op2)) {
case IS_STRING:
*result = zend_symtable_find(Z_ARR_P(op1), Z_STR_P(op2));
return SUCCESS;
default:
return FAILURE;
}
}
static inline int ct_eval_fetch_obj(zval *result, zval *op1, zval *op2) {
if (IS_PARTIAL_OBJECT(op1)) {
zval *value;
if (fetch_obj_prop(&value, op1, op2) == SUCCESS && value && !IS_BOT(value)) {
ZVAL_COPY(result, value);
return SUCCESS;
}
}
return FAILURE;
}
static inline int ct_eval_isset_obj(zval *result, uint32_t extended_value, zval *op1, zval *op2) {
if (IS_PARTIAL_OBJECT(op1)) {
zval *value;
if (fetch_obj_prop(&value, op1, op2) == FAILURE) {
return FAILURE;
}
if (!value || IS_BOT(value)) {
return FAILURE;
}
return ct_eval_isset_isempty(result, extended_value, value);
} else {
ZVAL_BOOL(result, (extended_value & ZEND_ISEMPTY));
return SUCCESS;
}
}
static inline int ct_eval_del_obj_prop(zval *result, zval *key) {
ZEND_ASSERT(IS_PARTIAL_OBJECT(result));
switch (Z_TYPE_P(key)) {
case IS_STRING:
zend_symtable_del(Z_ARR_P(result), Z_STR_P(key));
break;
default:
return FAILURE;
}
return SUCCESS;
}
static inline int ct_eval_add_obj_prop(zval *result, zval *value, zval *key) {
switch (Z_TYPE_P(key)) {
case IS_STRING:
value = zend_symtable_update(Z_ARR_P(result), Z_STR_P(key), value);
break;
default:
return FAILURE;
}
Z_TRY_ADDREF_P(value);
return SUCCESS;
}
static inline int ct_eval_assign_obj(zval *result, zval *value, zval *key) {
switch (Z_TYPE_P(result)) {
case IS_NULL:
case IS_FALSE:
empty_partial_object(result);
ZEND_FALLTHROUGH;
case PARTIAL_OBJECT:
return ct_eval_add_obj_prop(result, value, key);
default:
return FAILURE;
}
}
static inline int ct_eval_incdec(zval *result, zend_uchar opcode, zval *op1) {
if (Z_TYPE_P(op1) == IS_ARRAY || IS_PARTIAL_ARRAY(op1)) {
return FAILURE;
}
ZVAL_COPY(result, op1);
if (opcode == ZEND_PRE_INC
|| opcode == ZEND_POST_INC
|| opcode == ZEND_PRE_INC_OBJ
|| opcode == ZEND_POST_INC_OBJ) {
increment_function(result);
} else {
decrement_function(result);
}
return SUCCESS;
}
static inline void ct_eval_type_check(zval *result, uint32_t type_mask, zval *op1) {
uint32_t type = Z_TYPE_P(op1);
if (type == PARTIAL_ARRAY) {
type = IS_ARRAY;
} else if (type == PARTIAL_OBJECT) {
type = IS_OBJECT;
}
ZVAL_BOOL(result, (type_mask >> type) & 1);
}
static inline int ct_eval_in_array(zval *result, uint32_t extended_value, zval *op1, zval *op2) {
HashTable *ht;
bool res;
if (Z_TYPE_P(op2) != IS_ARRAY) {
return FAILURE;
}
ht = Z_ARRVAL_P(op2);
if (EXPECTED(Z_TYPE_P(op1) == IS_STRING)) {
res = zend_hash_exists(ht, Z_STR_P(op1));
} else if (extended_value) {
if (EXPECTED(Z_TYPE_P(op1) == IS_LONG)) {
res = zend_hash_index_exists(ht, Z_LVAL_P(op1));
} else {
res = 0;
}
} else if (Z_TYPE_P(op1) <= IS_FALSE) {
res = zend_hash_exists(ht, ZSTR_EMPTY_ALLOC());
} else {
zend_string *key;
zval key_tmp;
res = 0;
ZEND_HASH_FOREACH_STR_KEY(ht, key) {
ZVAL_STR(&key_tmp, key);
if (zend_compare(op1, &key_tmp) == 0) {
res = 1;
break;
}
} ZEND_HASH_FOREACH_END();
}
ZVAL_BOOL(result, res);
return SUCCESS;
}
static inline int ct_eval_array_key_exists(zval *result, zval *op1, zval *op2) {
zval *value;
if (Z_TYPE_P(op2) != IS_ARRAY && !IS_PARTIAL_ARRAY(op2)) {
return FAILURE;
}
if (Z_TYPE_P(op1) != IS_STRING && Z_TYPE_P(op1) != IS_LONG && Z_TYPE_P(op1) != IS_NULL) {
return FAILURE;
}
if (fetch_array_elem(&value, op2, op1) == FAILURE) {
return FAILURE;
}
if (IS_PARTIAL_ARRAY(op2) && (!value || IS_BOT(value))) {
return FAILURE;
}
ZVAL_BOOL(result, value != NULL);
return SUCCESS;
}
static bool can_ct_eval_func_call(zend_string *name, uint32_t num_args, zval **args) {
/* Functions in this list must always produce the same result for the same arguments,
* and have no dependence on global state (such as locales). It is okay if they throw
* or warn on invalid arguments, as we detect this and will discard the evaluation result. */
if (false
|| zend_string_equals_literal(name, "array_diff")
|| zend_string_equals_literal(name, "array_diff_assoc")
|| zend_string_equals_literal(name, "array_diff_key")
|| zend_string_equals_literal(name, "array_flip")
|| zend_string_equals_literal(name, "array_is_list")
|| zend_string_equals_literal(name, "array_key_exists")
|| zend_string_equals_literal(name, "array_keys")
|| zend_string_equals_literal(name, "array_merge")
|| zend_string_equals_literal(name, "array_merge_recursive")
|| zend_string_equals_literal(name, "array_replace")
|| zend_string_equals_literal(name, "array_replace_recursive")
|| zend_string_equals_literal(name, "array_unique")
|| zend_string_equals_literal(name, "array_values")
|| zend_string_equals_literal(name, "base64_decode")
|| zend_string_equals_literal(name, "base64_encode")
#ifndef ZEND_WIN32
/* On Windows this function may be code page dependent. */
|| zend_string_equals_literal(name, "dirname")
#endif
|| zend_string_equals_literal(name, "explode")
|| zend_string_equals_literal(name, "imagetypes")
|| zend_string_equals_literal(name, "in_array")
|| zend_string_equals_literal(name, "implode")
|| zend_string_equals_literal(name, "ltrim")
|| zend_string_equals_literal(name, "php_sapi_name")
|| zend_string_equals_literal(name, "php_uname")
|| zend_string_equals_literal(name, "phpversion")
|| zend_string_equals_literal(name, "pow")
|| zend_string_equals_literal(name, "preg_quote")
|| zend_string_equals_literal(name, "rawurldecode")
|| zend_string_equals_literal(name, "rawurlencode")
|| zend_string_equals_literal(name, "rtrim")
|| zend_string_equals_literal(name, "serialize")
|| zend_string_equals_literal(name, "str_contains")
|| zend_string_equals_literal(name, "str_ends_with")
|| zend_string_equals_literal(name, "str_replace")
|| zend_string_equals_literal(name, "str_split")
|| zend_string_equals_literal(name, "str_starts_with")
|| zend_string_equals_literal(name, "strpos")
|| zend_string_equals_literal(name, "strstr")
|| zend_string_equals_literal(name, "substr")
|| zend_string_equals_literal(name, "trim")
|| zend_string_equals_literal(name, "urldecode")
|| zend_string_equals_literal(name, "urlencode")
|| zend_string_equals_literal(name, "version_compare")
) {
return true;
}
if (num_args == 2) {
if (zend_string_equals_literal(name, "str_repeat")) {
/* Avoid creating overly large strings at compile-time. */
bool overflow;
return Z_TYPE_P(args[0]) == IS_STRING
&& Z_TYPE_P(args[1]) == IS_LONG
&& zend_safe_address(Z_STRLEN_P(args[0]), Z_LVAL_P(args[1]), 0, &overflow) < 64 * 1024
&& !overflow;
}
return false;
}
return false;
}
/* The functions chosen here are simple to implement and either likely to affect a branch,
* or just happened to be commonly used with constant operands in WP (need to test other
* applications as well, of course). */
static inline int ct_eval_func_call(
zend_op_array *op_array, zval *result, zend_string *name, uint32_t num_args, zval **args) {
uint32_t i;
zend_function *func = zend_hash_find_ptr(CG(function_table), name);
if (!func || func->type != ZEND_INTERNAL_FUNCTION) {
return FAILURE;
}
if (num_args == 1) {
/* Handle a few functions for which we manually implement evaluation here. */
if (zend_string_equals_literal(name, "chr")) {
zend_long c;
if (Z_TYPE_P(args[0]) != IS_LONG) {
return FAILURE;
}
c = Z_LVAL_P(args[0]) & 0xff;
ZVAL_CHAR(result, c);
return SUCCESS;
} else if (zend_string_equals_literal(name, "count")) {
if (Z_TYPE_P(args[0]) != IS_ARRAY) {
return FAILURE;
}
ZVAL_LONG(result, zend_hash_num_elements(Z_ARRVAL_P(args[0])));
return SUCCESS;
} else if (zend_string_equals_literal(name, "ini_get")) {
zend_ini_entry *ini_entry;
if (Z_TYPE_P(args[0]) != IS_STRING) {
return FAILURE;
}
ini_entry = zend_hash_find_ptr(EG(ini_directives), Z_STR_P(args[0]));
if (!ini_entry) {
if (PG(enable_dl)) {
return FAILURE;
}
ZVAL_FALSE(result);
} else if (ini_entry->modifiable != ZEND_INI_SYSTEM) {
return FAILURE;
} else if (ini_entry->value) {
ZVAL_STR_COPY(result, ini_entry->value);
} else {
ZVAL_EMPTY_STRING(result);
}
return SUCCESS;
}
}
if (!can_ct_eval_func_call(name, num_args, args)) {
return FAILURE;
}
zend_execute_data *prev_execute_data = EG(current_execute_data);
zend_execute_data *execute_data, dummy_frame;
zend_op dummy_opline;
/* Add a dummy frame to get the correct strict_types behavior. */
memset(&dummy_frame, 0, sizeof(zend_execute_data));
memset(&dummy_opline, 0, sizeof(zend_op));
dummy_frame.func = (zend_function *) op_array;
dummy_frame.opline = &dummy_opline;
dummy_opline.opcode = ZEND_DO_FCALL;
execute_data = safe_emalloc(num_args, sizeof(zval), ZEND_CALL_FRAME_SLOT * sizeof(zval));
memset(execute_data, 0, sizeof(zend_execute_data));
execute_data->prev_execute_data = &dummy_frame;
EG(current_execute_data) = execute_data;
/* Enable suppression and counting of warnings. */
ZEND_ASSERT(EG(capture_warnings_during_sccp) == 0);
EG(capture_warnings_during_sccp) = 1;
EX(func) = func;
EX_NUM_ARGS() = num_args;
for (i = 0; i < num_args; i++) {
ZVAL_COPY(EX_VAR_NUM(i), args[i]);
}
ZVAL_NULL(result);
func->internal_function.handler(execute_data, result);
for (i = 0; i < num_args; i++) {
zval_ptr_dtor_nogc(EX_VAR_NUM(i));
}
int retval = SUCCESS;
if (EG(exception)) {
zval_ptr_dtor(result);
zend_clear_exception();
retval = FAILURE;
}
if (EG(capture_warnings_during_sccp) > 1) {
zval_ptr_dtor(result);
retval = FAILURE;
}
EG(capture_warnings_during_sccp) = 0;
efree(execute_data);
EG(current_execute_data) = prev_execute_data;
return retval;
}
#define SET_RESULT(op, zv) do { \
if (ssa_op->op##_def >= 0) { \
set_value(scdf, ctx, ssa_op->op##_def, zv); \
} \
} while (0)
#define SET_RESULT_BOT(op) SET_RESULT(op, &ctx->bot)
#define SET_RESULT_TOP(op) SET_RESULT(op, &ctx->top)
#define SKIP_IF_TOP(op) if (IS_TOP(op)) return;
static void sccp_visit_instr(scdf_ctx *scdf, zend_op *opline, zend_ssa_op *ssa_op) {
sccp_ctx *ctx = (sccp_ctx *) scdf;
zval *op1, *op2, zv; /* zv is a temporary to hold result values */
op1 = get_op1_value(ctx, opline, ssa_op);
op2 = get_op2_value(ctx, opline, ssa_op);
switch (opline->opcode) {
case ZEND_ASSIGN:
/* The value of op1 is irrelevant here, because we are overwriting it
* -- unless it can be a reference, in which case we propagate a BOT.