summaryrefslogtreecommitdiffstats
path: root/js/src/jit/VMFunctions.h
blob: 94f74139717b90a314a94bf5eb3d861468ac56c8 (plain)
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
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * vim: set ts=8 sts=4 et sw=4 tw=99:
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef jit_VMFunctions_h
#define jit_VMFunctions_h

#include "mozilla/Attributes.h"

#include "jspubtd.h"

#include "jit/CompileInfo.h"
#include "jit/JitFrames.h"
#include "vm/Interpreter.h"

namespace js {

class NamedLambdaObject;
class WithScope;
class InlineTypedObject;
class GeneratorObject;
class TypedArrayObject;

namespace jit {

enum DataType {
    Type_Void,
    Type_Bool,
    Type_Int32,
    Type_Double,
    Type_Pointer,
    Type_Object,
    Type_Value,
    Type_Handle
};

struct PopValues
{
    uint32_t numValues;

    explicit PopValues(uint32_t numValues)
      : numValues(numValues)
    { }
};

enum MaybeTailCall {
    TailCall,
    NonTailCall
};

// Contains information about a virtual machine function that can be called
// from JIT code. Functions described in this manner must conform to a simple
// protocol: the return type must have a special "failure" value (for example,
// false for bool, or nullptr for Objects). If the function is designed to
// return a value that does not meet this requirement - such as
// object-or-nullptr, or an integer, an optional, final outParam can be
// specified. In this case, the return type must be boolean to indicate
// failure.
//
// All functions described by VMFunction take a JSContext * as a first
// argument, and are treated as re-entrant into the VM and therefore fallible.
struct VMFunction
{
    // Global linked list of all VMFunctions.
    static VMFunction* functions;
    VMFunction* next;

    // Address of the C function.
    void* wrapped;

    const char* name_;

    // Number of arguments expected, excluding JSContext * as an implicit
    // first argument and an outparam as a possible implicit final argument.
    uint32_t explicitArgs;

    enum ArgProperties {
        WordByValue = 0,
        DoubleByValue = 1,
        WordByRef = 2,
        DoubleByRef = 3,
        // BitMask version.
        Word = 0,
        Double = 1,
        ByRef = 2
    };

    // Contains properties about the first 16 arguments.
    uint32_t argumentProperties;

    // Which arguments should be passed in float register on platforms that
    // have them.
    uint32_t argumentPassedInFloatRegs;

    // The outparam may be any Type_*, and must be the final argument to the
    // function, if not Void. outParam != Void implies that the return type
    // has a boolean failure mode.
    DataType outParam;

    // Type returned by the C function and used by the VMFunction wrapper to
    // check for failures of the C function.  Valid failure/return types are
    // boolean and object pointers which are asserted inside the VMFunction
    // constructor. If the C function use an outparam (!= Type_Void), then
    // the only valid failure/return type is boolean -- object pointers are
    // pointless because the wrapper will only use it to compare it against
    // nullptr before discarding its value.
    DataType returnType;

    // Note: a maximum of seven root types is supported.
    enum RootType {
        RootNone = 0,
        RootObject,
        RootString,
        RootPropertyName,
        RootFunction,
        RootValue,
        RootCell
    };

    // Contains an combination of enumerated types used by the gc for marking
    // arguments of the VM wrapper.
    uint64_t argumentRootTypes;

    // The root type of the out param if outParam == Type_Handle.
    RootType outParamRootType;

    // Number of Values the VM wrapper should pop from the stack when it returns.
    // Used by baseline IC stubs so that they can use tail calls to call the VM
    // wrapper.
    uint32_t extraValuesToPop;

    // On some architectures, called functions need to explicitly push their
    // return address, for a tail call, there is nothing to push, so tail-callness
    // needs to be known at compile time.
    MaybeTailCall expectTailCall;

    uint32_t argc() const {
        // JSContext * + args + (OutParam? *)
        return 1 + explicitArgc() + ((outParam == Type_Void) ? 0 : 1);
    }

    DataType failType() const {
        return returnType;
    }

    ArgProperties argProperties(uint32_t explicitArg) const {
        return ArgProperties((argumentProperties >> (2 * explicitArg)) & 3);
    }

    RootType argRootType(uint32_t explicitArg) const {
        return RootType((argumentRootTypes >> (3 * explicitArg)) & 7);
    }

    bool argPassedInFloatReg(uint32_t explicitArg) const {
        return ((argumentPassedInFloatRegs >> explicitArg) & 1) == 1;
    }

    const char* name() const {
        return name_;
    }

    // Return the stack size consumed by explicit arguments.
    size_t explicitStackSlots() const {
        size_t stackSlots = explicitArgs;

        // Fetch all double-word flags of explicit arguments.
        uint32_t n =
            ((1 << (explicitArgs * 2)) - 1) // = Explicit argument mask.
            & 0x55555555                    // = Mask double-size args.
            & argumentProperties;

        // Add the number of double-word flags. (expect a few loop
        // iteration)
        while (n) {
            stackSlots++;
            n &= n - 1;
        }
        return stackSlots;
    }

    // Double-size argument which are passed by value are taking the space
    // of 2 C arguments.  This function is used to compute the number of
    // argument expected by the C function.  This is not the same as
    // explicitStackSlots because reference to stack slots may take one less
    // register in the total count.
    size_t explicitArgc() const {
        size_t stackSlots = explicitArgs;

        // Fetch all explicit arguments.
        uint32_t n =
            ((1 << (explicitArgs * 2)) - 1) // = Explicit argument mask.
            & argumentProperties;

        // Filter double-size arguments (0x5 = 0b0101) and remove (& ~)
        // arguments passed by reference (0b1010 >> 1 == 0b0101).
        n = (n & 0x55555555) & ~(n >> 1);

        // Add the number of double-word transfered by value. (expect a few
        // loop iteration)
        while (n) {
            stackSlots++;
            n &= n - 1;
        }
        return stackSlots;
    }

    size_t doubleByRefArgs() const {
        size_t count = 0;

        // Fetch all explicit arguments.
        uint32_t n =
            ((1 << (explicitArgs * 2)) - 1) // = Explicit argument mask.
            & argumentProperties;

        // Filter double-size arguments (0x5 = 0b0101) and take (&) only
        // arguments passed by reference (0b1010 >> 1 == 0b0101).
        n = (n & 0x55555555) & (n >> 1);

        // Add the number of double-word transfered by refference. (expect a
        // few loop iterations)
        while (n) {
            count++;
            n &= n - 1;
        }
        return count;
    }

    VMFunction(void* wrapped, const char* name, uint32_t explicitArgs, uint32_t argumentProperties,
               uint32_t argumentPassedInFloatRegs, uint64_t argRootTypes,
               DataType outParam, RootType outParamRootType, DataType returnType,
               uint32_t extraValuesToPop = 0, MaybeTailCall expectTailCall = NonTailCall)
      : wrapped(wrapped),
        name_(name),
        explicitArgs(explicitArgs),
        argumentProperties(argumentProperties),
        argumentPassedInFloatRegs(argumentPassedInFloatRegs),
        outParam(outParam),
        returnType(returnType),
        argumentRootTypes(argRootTypes),
        outParamRootType(outParamRootType),
        extraValuesToPop(extraValuesToPop),
        expectTailCall(expectTailCall)
    {
        // Check for valid failure/return type.
        MOZ_ASSERT_IF(outParam != Type_Void, returnType == Type_Bool);
        MOZ_ASSERT(returnType == Type_Bool ||
                   returnType == Type_Object);
    }

    VMFunction(const VMFunction& o) {
        *this = o;
        addToFunctions();
    }

  private:
    // Add this to the global list of VMFunctions.
    void addToFunctions();
};

template <class> struct TypeToDataType { /* Unexpected return type for a VMFunction. */ };
template <> struct TypeToDataType<bool> { static const DataType result = Type_Bool; };
template <> struct TypeToDataType<JSObject*> { static const DataType result = Type_Object; };
template <> struct TypeToDataType<NativeObject*> { static const DataType result = Type_Object; };
template <> struct TypeToDataType<PlainObject*> { static const DataType result = Type_Object; };
template <> struct TypeToDataType<InlineTypedObject*> { static const DataType result = Type_Object; };
template <> struct TypeToDataType<NamedLambdaObject*> { static const DataType result = Type_Object; };
template <> struct TypeToDataType<ArrayObject*> { static const DataType result = Type_Object; };
template <> struct TypeToDataType<TypedArrayObject*> { static const DataType result = Type_Object; };
template <> struct TypeToDataType<JSString*> { static const DataType result = Type_Object; };
template <> struct TypeToDataType<JSFlatString*> { static const DataType result = Type_Object; };
template <> struct TypeToDataType<HandleObject> { static const DataType result = Type_Handle; };
template <> struct TypeToDataType<HandleString> { static const DataType result = Type_Handle; };
template <> struct TypeToDataType<HandlePropertyName> { static const DataType result = Type_Handle; };
template <> struct TypeToDataType<HandleFunction> { static const DataType result = Type_Handle; };
template <> struct TypeToDataType<Handle<NativeObject*> > { static const DataType result = Type_Handle; };
template <> struct TypeToDataType<Handle<InlineTypedObject*> > { static const DataType result = Type_Handle; };
template <> struct TypeToDataType<Handle<ArrayObject*> > { static const DataType result = Type_Handle; };
template <> struct TypeToDataType<Handle<GeneratorObject*> > { static const DataType result = Type_Handle; };
template <> struct TypeToDataType<Handle<PlainObject*> > { static const DataType result = Type_Handle; };
template <> struct TypeToDataType<Handle<WithScope*> > { static const DataType result = Type_Handle; };
template <> struct TypeToDataType<Handle<LexicalScope*> > { static const DataType result = Type_Handle; };
template <> struct TypeToDataType<Handle<Scope*> > { static const DataType result = Type_Handle; };
template <> struct TypeToDataType<HandleScript> { static const DataType result = Type_Handle; };
template <> struct TypeToDataType<HandleValue> { static const DataType result = Type_Handle; };
template <> struct TypeToDataType<MutableHandleValue> { static const DataType result = Type_Handle; };

// Convert argument types to properties of the argument known by the jit.
template <class T> struct TypeToArgProperties {
    static const uint32_t result =
        (sizeof(T) <= sizeof(void*) ? VMFunction::Word : VMFunction::Double);
};
template <> struct TypeToArgProperties<const Value&> {
    static const uint32_t result = TypeToArgProperties<Value>::result | VMFunction::ByRef;
};
template <> struct TypeToArgProperties<HandleObject> {
    static const uint32_t result = TypeToArgProperties<JSObject*>::result | VMFunction::ByRef;
};
template <> struct TypeToArgProperties<HandleString> {
    static const uint32_t result = TypeToArgProperties<JSString*>::result | VMFunction::ByRef;
};
template <> struct TypeToArgProperties<HandlePropertyName> {
    static const uint32_t result = TypeToArgProperties<PropertyName*>::result | VMFunction::ByRef;
};
template <> struct TypeToArgProperties<HandleFunction> {
    static const uint32_t result = TypeToArgProperties<JSFunction*>::result | VMFunction::ByRef;
};
template <> struct TypeToArgProperties<Handle<NativeObject*> > {
    static const uint32_t result = TypeToArgProperties<NativeObject*>::result | VMFunction::ByRef;
};
template <> struct TypeToArgProperties<Handle<InlineTypedObject*> > {
    static const uint32_t result = TypeToArgProperties<InlineTypedObject*>::result | VMFunction::ByRef;
};
template <> struct TypeToArgProperties<Handle<ArrayObject*> > {
    static const uint32_t result = TypeToArgProperties<ArrayObject*>::result | VMFunction::ByRef;
};
template <> struct TypeToArgProperties<Handle<GeneratorObject*> > {
    static const uint32_t result = TypeToArgProperties<GeneratorObject*>::result | VMFunction::ByRef;
};
template <> struct TypeToArgProperties<Handle<PlainObject*> > {
    static const uint32_t result = TypeToArgProperties<PlainObject*>::result | VMFunction::ByRef;
};
template <> struct TypeToArgProperties<Handle<WithScope*> > {
    static const uint32_t result = TypeToArgProperties<WithScope*>::result | VMFunction::ByRef;
};
template <> struct TypeToArgProperties<Handle<LexicalScope*> > {
    static const uint32_t result = TypeToArgProperties<LexicalScope*>::result | VMFunction::ByRef;
};
template <> struct TypeToArgProperties<Handle<Scope*> > {
    static const uint32_t result = TypeToArgProperties<Scope*>::result | VMFunction::ByRef;
};
template <> struct TypeToArgProperties<HandleScript> {
    static const uint32_t result = TypeToArgProperties<JSScript*>::result | VMFunction::ByRef;
};
template <> struct TypeToArgProperties<HandleValue> {
    static const uint32_t result = TypeToArgProperties<Value>::result | VMFunction::ByRef;
};
template <> struct TypeToArgProperties<MutableHandleValue> {
    static const uint32_t result = TypeToArgProperties<Value>::result | VMFunction::ByRef;
};
template <> struct TypeToArgProperties<HandleShape> {
    static const uint32_t result = TypeToArgProperties<Shape*>::result | VMFunction::ByRef;
};
template <> struct TypeToArgProperties<HandleObjectGroup> {
    static const uint32_t result = TypeToArgProperties<ObjectGroup*>::result | VMFunction::ByRef;
};

// Convert argument type to whether or not it should be passed in a float
// register on platforms that have them, like x64.
template <class T> struct TypeToPassInFloatReg {
    static const uint32_t result = 0;
};
template <> struct TypeToPassInFloatReg<double> {
    static const uint32_t result = 1;
};

// Convert argument types to root types used by the gc, see MarkJitExitFrame.
template <class T> struct TypeToRootType {
    static const uint32_t result = VMFunction::RootNone;
};
template <> struct TypeToRootType<HandleObject> {
    static const uint32_t result = VMFunction::RootObject;
};
template <> struct TypeToRootType<HandleString> {
    static const uint32_t result = VMFunction::RootString;
};
template <> struct TypeToRootType<HandlePropertyName> {
    static const uint32_t result = VMFunction::RootPropertyName;
};
template <> struct TypeToRootType<HandleFunction> {
    static const uint32_t result = VMFunction::RootFunction;
};
template <> struct TypeToRootType<HandleValue> {
    static const uint32_t result = VMFunction::RootValue;
};
template <> struct TypeToRootType<MutableHandleValue> {
    static const uint32_t result = VMFunction::RootValue;
};
template <> struct TypeToRootType<HandleShape> {
    static const uint32_t result = VMFunction::RootCell;
};
template <> struct TypeToRootType<HandleObjectGroup> {
    static const uint32_t result = VMFunction::RootCell;
};
template <> struct TypeToRootType<HandleScript> {
    static const uint32_t result = VMFunction::RootCell;
};
template <> struct TypeToRootType<Handle<NativeObject*> > {
    static const uint32_t result = VMFunction::RootObject;
};
template <> struct TypeToRootType<Handle<InlineTypedObject*> > {
    static const uint32_t result = VMFunction::RootObject;
};
template <> struct TypeToRootType<Handle<ArrayObject*> > {
    static const uint32_t result = VMFunction::RootObject;
};
template <> struct TypeToRootType<Handle<GeneratorObject*> > {
    static const uint32_t result = VMFunction::RootObject;
};
template <> struct TypeToRootType<Handle<PlainObject*> > {
    static const uint32_t result = VMFunction::RootObject;
};
template <> struct TypeToRootType<Handle<LexicalScope*> > {
    static const uint32_t result = VMFunction::RootCell;
};
template <> struct TypeToRootType<Handle<WithScope*> > {
    static const uint32_t result = VMFunction::RootCell;
};
template <> struct TypeToRootType<Handle<Scope*> > {
    static const uint32_t result = VMFunction::RootCell;
};
template <class T> struct TypeToRootType<Handle<T> > {
    // Fail for Handle types that aren't specialized above.
};

template <class> struct OutParamToDataType { static const DataType result = Type_Void; };
template <> struct OutParamToDataType<Value*> { static const DataType result = Type_Value; };
template <> struct OutParamToDataType<int*> { static const DataType result = Type_Int32; };
template <> struct OutParamToDataType<uint32_t*> { static const DataType result = Type_Int32; };
template <> struct OutParamToDataType<uint8_t**> { static const DataType result = Type_Pointer; };
template <> struct OutParamToDataType<bool*> { static const DataType result = Type_Bool; };
template <> struct OutParamToDataType<double*> { static const DataType result = Type_Double; };
template <> struct OutParamToDataType<MutableHandleValue> { static const DataType result = Type_Handle; };
template <> struct OutParamToDataType<MutableHandleObject> { static const DataType result = Type_Handle; };
template <> struct OutParamToDataType<MutableHandleString> { static const DataType result = Type_Handle; };

template <class> struct OutParamToRootType {
    static const VMFunction::RootType result = VMFunction::RootNone;
};
template <> struct OutParamToRootType<MutableHandleValue> {
    static const VMFunction::RootType result = VMFunction::RootValue;
};
template <> struct OutParamToRootType<MutableHandleObject> {
    static const VMFunction::RootType result = VMFunction::RootObject;
};
template <> struct OutParamToRootType<MutableHandleString> {
    static const VMFunction::RootType result = VMFunction::RootString;
};

template <class> struct MatchContext { };
template <> struct MatchContext<JSContext*> {
    static const bool valid = true;
};
template <> struct MatchContext<ExclusiveContext*> {
    static const bool valid = true;
};

// Extract the last element of a list of types.
template <typename... ArgTypes>
struct LastArg;

template <>
struct LastArg<>
{
    typedef void Type;
    static constexpr size_t nbArgs = 0;
};

template <typename HeadType>
struct LastArg<HeadType>
{
    typedef HeadType Type;
    static constexpr size_t nbArgs = 1;
};

template <typename HeadType, typename... TailTypes>
struct LastArg<HeadType, TailTypes...>
{
    typedef typename LastArg<TailTypes...>::Type Type;
    static constexpr size_t nbArgs = LastArg<TailTypes...>::nbArgs + 1;
};

// Construct a bit mask from a list of types.  The mask is constructed as an OR
// of the mask produced for each argument. The result of each argument is
// shifted by its index, such that the result of the first argument is on the
// low bits of the mask, and the result of the last argument in part of the
// high bits of the mask.
template <template<typename> class Each, typename ResultType, size_t Shift,
          typename... Args>
struct BitMask;

template <template<typename> class Each, typename ResultType, size_t Shift>
struct BitMask<Each, ResultType, Shift>
{
    static constexpr ResultType result = ResultType();
};

template <template<typename> class Each, typename ResultType, size_t Shift,
          typename HeadType, typename... TailTypes>
struct BitMask<Each, ResultType, Shift, HeadType, TailTypes...>
{
    static_assert(ResultType(Each<HeadType>::result) < (1 << Shift),
                  "not enough bits reserved by the shift for individual results");
    static_assert(LastArg<TailTypes...>::nbArgs < (8 * sizeof(ResultType) / Shift),
                  "not enough bits in the result type to store all bit masks");

    static constexpr ResultType result =
        ResultType(Each<HeadType>::result) |
        (BitMask<Each, ResultType, Shift, TailTypes...>::result << Shift);
};

// Extract VMFunction properties based on the signature of the function. The
// properties are used to generate the logic for calling the VM function, and
// also for marking the stack during GCs.
template <typename... Args>
struct FunctionInfo;

template <class R, class Context, typename... Args>
struct FunctionInfo<R (*)(Context, Args...)> : public VMFunction
{
    typedef R (*pf)(Context, Args...);

    static DataType returnType() {
        return TypeToDataType<R>::result;
    }
    static DataType outParam() {
        return OutParamToDataType<typename LastArg<Args...>::Type>::result;
    }
    static RootType outParamRootType() {
        return OutParamToRootType<typename LastArg<Args...>::Type>::result;
    }
    static size_t NbArgs() {
        return LastArg<Args...>::nbArgs;
    }
    static size_t explicitArgs() {
        return NbArgs() - (outParam() != Type_Void ? 1 : 0);
    }
    static uint32_t argumentProperties() {
        return BitMask<TypeToArgProperties, uint32_t, 2, Args...>::result;
    }
    static uint32_t argumentPassedInFloatRegs() {
        return BitMask<TypeToPassInFloatReg, uint32_t, 2, Args...>::result;
    }
    static uint64_t argumentRootTypes() {
        return BitMask<TypeToRootType, uint64_t, 3, Args...>::result;
    }
    explicit FunctionInfo(pf fun, const char* name, PopValues extraValuesToPop = PopValues(0))
        : VMFunction(JS_FUNC_TO_DATA_PTR(void*, fun), name, explicitArgs(),
                     argumentProperties(), argumentPassedInFloatRegs(),
                     argumentRootTypes(), outParam(), outParamRootType(),
                     returnType(), extraValuesToPop.numValues, NonTailCall)
    {
        static_assert(MatchContext<Context>::valid, "Invalid cx type in VMFunction");
    }
    explicit FunctionInfo(pf fun, const char* name, MaybeTailCall expectTailCall,
                          PopValues extraValuesToPop = PopValues(0))
        : VMFunction(JS_FUNC_TO_DATA_PTR(void*, fun), name, explicitArgs(),
                     argumentProperties(), argumentPassedInFloatRegs(),
                     argumentRootTypes(), outParam(), outParamRootType(),
                     returnType(), extraValuesToPop.numValues, expectTailCall)
    {
        static_assert(MatchContext<Context>::valid, "Invalid cx type in VMFunction");
    }
};

class AutoDetectInvalidation
{
    JSContext* cx_;
    IonScript* ionScript_;
    MutableHandleValue rval_;
    bool disabled_;

    void setReturnOverride();

  public:
    AutoDetectInvalidation(JSContext* cx, MutableHandleValue rval, IonScript* ionScript)
      : cx_(cx), ionScript_(ionScript), rval_(rval), disabled_(false)
    {
        MOZ_ASSERT(ionScript);
    }

    AutoDetectInvalidation(JSContext* cx, MutableHandleValue rval);

    void disable() {
        MOZ_ASSERT(!disabled_);
        disabled_ = true;
    }

    ~AutoDetectInvalidation() {
        if (!disabled_ && ionScript_->invalidated())
            setReturnOverride();
    }
};

MOZ_MUST_USE bool
InvokeFunction(JSContext* cx, HandleObject obj0, bool constructing, bool ignoresReturnValue,
               uint32_t argc, Value* argv, MutableHandleValue rval);
MOZ_MUST_USE bool
InvokeFunctionShuffleNewTarget(JSContext* cx, HandleObject obj, uint32_t numActualArgs,
                               uint32_t numFormalArgs, Value* argv, MutableHandleValue rval);

bool CheckOverRecursed(JSContext* cx);
bool CheckOverRecursedWithExtra(JSContext* cx, BaselineFrame* frame,
                                uint32_t extra, uint32_t earlyCheck);

JSObject* BindVar(JSContext* cx, HandleObject scopeChain);
MOZ_MUST_USE bool
DefVar(JSContext* cx, HandlePropertyName dn, unsigned attrs, HandleObject scopeChain);
MOZ_MUST_USE bool
DefLexical(JSContext* cx, HandlePropertyName dn, unsigned attrs, HandleObject scopeChain);
MOZ_MUST_USE bool
DefGlobalLexical(JSContext* cx, HandlePropertyName dn, unsigned attrs);
MOZ_MUST_USE bool
MutatePrototype(JSContext* cx, HandlePlainObject obj, HandleValue value);
MOZ_MUST_USE bool
InitProp(JSContext* cx, HandleObject obj, HandlePropertyName name, HandleValue value,
         jsbytecode* pc);

template<bool Equal>
bool LooselyEqual(JSContext* cx, MutableHandleValue lhs, MutableHandleValue rhs, bool* res);

template<bool Equal>
bool StrictlyEqual(JSContext* cx, MutableHandleValue lhs, MutableHandleValue rhs, bool* res);

bool LessThan(JSContext* cx, MutableHandleValue lhs, MutableHandleValue rhs, bool* res);
bool LessThanOrEqual(JSContext* cx, MutableHandleValue lhs, MutableHandleValue rhs, bool* res);
bool GreaterThan(JSContext* cx, MutableHandleValue lhs, MutableHandleValue rhs, bool* res);
bool GreaterThanOrEqual(JSContext* cx, MutableHandleValue lhs, MutableHandleValue rhs, bool* res);

template<bool Equal>
bool StringsEqual(JSContext* cx, HandleString left, HandleString right, bool* res);

MOZ_MUST_USE bool ArrayPopDense(JSContext* cx, HandleObject obj, MutableHandleValue rval);
MOZ_MUST_USE bool ArrayPushDense(JSContext* cx, HandleArrayObject obj, HandleValue v, uint32_t* length);
MOZ_MUST_USE bool ArrayShiftDense(JSContext* cx, HandleObject obj, MutableHandleValue rval);
JSString* ArrayJoin(JSContext* cx, HandleObject array, HandleString sep);

MOZ_MUST_USE bool
CharCodeAt(JSContext* cx, HandleString str, int32_t index, uint32_t* code);
JSFlatString* StringFromCharCode(JSContext* cx, int32_t code);
JSString* StringFromCodePoint(JSContext* cx, int32_t codePoint);

MOZ_MUST_USE bool
SetProperty(JSContext* cx, HandleObject obj, HandlePropertyName name, HandleValue value,
            bool strict, jsbytecode* pc);

MOZ_MUST_USE bool
InterruptCheck(JSContext* cx);

void* MallocWrapper(JSRuntime* rt, size_t nbytes);
JSObject* NewCallObject(JSContext* cx, HandleShape shape, HandleObjectGroup group);
JSObject* NewSingletonCallObject(JSContext* cx, HandleShape shape);
JSObject* NewStringObject(JSContext* cx, HandleString str);

bool OperatorIn(JSContext* cx, HandleValue key, HandleObject obj, bool* out);
bool OperatorInI(JSContext* cx, uint32_t index, HandleObject obj, bool* out);

MOZ_MUST_USE bool
GetIntrinsicValue(JSContext* cx, HandlePropertyName name, MutableHandleValue rval);

MOZ_MUST_USE bool
CreateThis(JSContext* cx, HandleObject callee, HandleObject newTarget, MutableHandleValue rval);

void GetDynamicName(JSContext* cx, JSObject* scopeChain, JSString* str, Value* vp);

void PostWriteBarrier(JSRuntime* rt, JSObject* obj);
void PostWriteElementBarrier(JSRuntime* rt, JSObject* obj, int32_t index);
void PostGlobalWriteBarrier(JSRuntime* rt, JSObject* obj);

uint32_t GetIndexFromString(JSString* str);

MOZ_MUST_USE bool
DebugPrologue(JSContext* cx, BaselineFrame* frame, jsbytecode* pc, bool* mustReturn);
MOZ_MUST_USE bool
DebugEpilogue(JSContext* cx, BaselineFrame* frame, jsbytecode* pc, bool ok);
MOZ_MUST_USE bool
DebugEpilogueOnBaselineReturn(JSContext* cx, BaselineFrame* frame, jsbytecode* pc);
void FrameIsDebuggeeCheck(BaselineFrame* frame);

JSObject* CreateGenerator(JSContext* cx, BaselineFrame* frame);

MOZ_MUST_USE bool
NormalSuspend(JSContext* cx, HandleObject obj, BaselineFrame* frame, jsbytecode* pc,
              uint32_t stackDepth);
MOZ_MUST_USE bool
FinalSuspend(JSContext* cx, HandleObject obj, BaselineFrame* frame, jsbytecode* pc);
MOZ_MUST_USE bool
InterpretResume(JSContext* cx, HandleObject obj, HandleValue val, HandlePropertyName kind,
                MutableHandleValue rval);
MOZ_MUST_USE bool
DebugAfterYield(JSContext* cx, BaselineFrame* frame);
MOZ_MUST_USE bool
GeneratorThrowOrClose(JSContext* cx, BaselineFrame* frame, Handle<GeneratorObject*> genObj,
                      HandleValue arg, uint32_t resumeKind);

MOZ_MUST_USE bool
GlobalNameConflictsCheckFromIon(JSContext* cx, HandleScript script);
MOZ_MUST_USE bool
CheckGlobalOrEvalDeclarationConflicts(JSContext* cx, BaselineFrame* frame);
MOZ_MUST_USE bool
InitFunctionEnvironmentObjects(JSContext* cx, BaselineFrame* frame);

MOZ_MUST_USE bool
NewArgumentsObject(JSContext* cx, BaselineFrame* frame, MutableHandleValue res);

JSObject* InitRestParameter(JSContext* cx, uint32_t length, Value* rest, HandleObject templateObj,
                            HandleObject res);

MOZ_MUST_USE bool
HandleDebugTrap(JSContext* cx, BaselineFrame* frame, uint8_t* retAddr, bool* mustReturn);
MOZ_MUST_USE bool
OnDebuggerStatement(JSContext* cx, BaselineFrame* frame, jsbytecode* pc, bool* mustReturn);
MOZ_MUST_USE bool
GlobalHasLiveOnDebuggerStatement(JSContext* cx);

MOZ_MUST_USE bool
EnterWith(JSContext* cx, BaselineFrame* frame, HandleValue val, Handle<WithScope*> templ);
MOZ_MUST_USE bool
LeaveWith(JSContext* cx, BaselineFrame* frame);

MOZ_MUST_USE bool
PushLexicalEnv(JSContext* cx, BaselineFrame* frame, Handle<LexicalScope*> scope);
MOZ_MUST_USE bool
PopLexicalEnv(JSContext* cx, BaselineFrame* frame);
MOZ_MUST_USE bool
DebugLeaveThenPopLexicalEnv(JSContext* cx, BaselineFrame* frame, jsbytecode* pc);
MOZ_MUST_USE bool
FreshenLexicalEnv(JSContext* cx, BaselineFrame* frame);
MOZ_MUST_USE bool
DebugLeaveThenFreshenLexicalEnv(JSContext* cx, BaselineFrame* frame, jsbytecode* pc);
MOZ_MUST_USE bool
RecreateLexicalEnv(JSContext* cx, BaselineFrame* frame);
MOZ_MUST_USE bool
DebugLeaveThenRecreateLexicalEnv(JSContext* cx, BaselineFrame* frame, jsbytecode* pc);
MOZ_MUST_USE bool
DebugLeaveLexicalEnv(JSContext* cx, BaselineFrame* frame, jsbytecode* pc);

MOZ_MUST_USE bool
PushVarEnv(JSContext* cx, BaselineFrame* frame, HandleScope scope);
MOZ_MUST_USE bool
PopVarEnv(JSContext* cx, BaselineFrame* frame);

MOZ_MUST_USE bool
InitBaselineFrameForOsr(BaselineFrame* frame, InterpreterFrame* interpFrame,
                             uint32_t numStackValues);

JSObject* CreateDerivedTypedObj(JSContext* cx, HandleObject descr,
                                HandleObject owner, int32_t offset);

MOZ_MUST_USE bool
Recompile(JSContext* cx);
MOZ_MUST_USE bool
ForcedRecompile(JSContext* cx);
JSString* StringReplace(JSContext* cx, HandleString string, HandleString pattern,
                        HandleString repl);

MOZ_MUST_USE bool SetDenseElement(JSContext* cx, HandleNativeObject obj, int32_t index,
                                  HandleValue value, bool strict);

void AssertValidObjectPtr(JSContext* cx, JSObject* obj);
void AssertValidObjectOrNullPtr(JSContext* cx, JSObject* obj);
void AssertValidStringPtr(JSContext* cx, JSString* str);
void AssertValidSymbolPtr(JSContext* cx, JS::Symbol* sym);
void AssertValidValue(JSContext* cx, Value* v);

void MarkValueFromIon(JSRuntime* rt, Value* vp);
void MarkStringFromIon(JSRuntime* rt, JSString** stringp);
void MarkObjectFromIon(JSRuntime* rt, JSObject** objp);
void MarkShapeFromIon(JSRuntime* rt, Shape** shapep);
void MarkObjectGroupFromIon(JSRuntime* rt, ObjectGroup** groupp);

// Helper for generatePreBarrier.
inline void*
IonMarkFunction(MIRType type)
{
    switch (type) {
      case MIRType::Value:
        return JS_FUNC_TO_DATA_PTR(void*, MarkValueFromIon);
      case MIRType::String:
        return JS_FUNC_TO_DATA_PTR(void*, MarkStringFromIon);
      case MIRType::Object:
        return JS_FUNC_TO_DATA_PTR(void*, MarkObjectFromIon);
      case MIRType::Shape:
        return JS_FUNC_TO_DATA_PTR(void*, MarkShapeFromIon);
      case MIRType::ObjectGroup:
        return JS_FUNC_TO_DATA_PTR(void*, MarkObjectGroupFromIon);
      default: MOZ_CRASH();
    }
}

bool ObjectIsCallable(JSObject* obj);
bool ObjectIsConstructor(JSObject* obj);

MOZ_MUST_USE bool
ThrowRuntimeLexicalError(JSContext* cx, unsigned errorNumber);

MOZ_MUST_USE bool
ThrowReadOnlyError(JSContext* cx, int32_t index);

MOZ_MUST_USE bool
BaselineThrowUninitializedThis(JSContext* cx, BaselineFrame* frame);

MOZ_MUST_USE bool
ThrowBadDerivedReturn(JSContext* cx, HandleValue v);

MOZ_MUST_USE bool
ThrowObjectCoercible(JSContext* cx, HandleValue v);

MOZ_MUST_USE bool
BaselineGetFunctionThis(JSContext* cx, BaselineFrame* frame, MutableHandleValue res);

MOZ_MUST_USE bool
CheckIsCallable(JSContext* cx, HandleValue v, CheckIsCallableKind kind);

} // namespace jit
} // namespace js

#endif /* jit_VMFunctions_h */