1/*
2 * Copyright (C) 2008, 2009, 2013, 2014 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1.  Redistributions of source code must retain the above copyright
9 *     notice, this list of conditions and the following disclaimer.
10 * 2.  Redistributions in binary form must reproduce the above copyright
11 *     notice, this list of conditions and the following disclaimer in the
12 *     documentation and/or other materials provided with the distribution.
13 * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
14 *     its contributors may be used to endorse or promote products derived
15 *     from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#ifndef VM_h
30#define VM_h
31
32#include "DateInstanceCache.h"
33#include "ExecutableAllocator.h"
34#include "Heap.h"
35#include "Intrinsic.h"
36#include "JITThunks.h"
37#include "JSCJSValue.h"
38#include "JSLock.h"
39#include "LLIntData.h"
40#include "MacroAssemblerCodeRef.h"
41#include "NumericStrings.h"
42#include "PrivateName.h"
43#include "PrototypeMap.h"
44#include "SmallStrings.h"
45#include "SourceCode.h"
46#include "Strong.h"
47#include "ThunkGenerators.h"
48#include "TypedArrayController.h"
49#include "Watchdog.h"
50#include "Watchpoint.h"
51#include "WeakRandom.h"
52#include <wtf/BumpPointerAllocator.h>
53#include <wtf/DateMath.h>
54#include <wtf/Forward.h>
55#include <wtf/HashMap.h>
56#include <wtf/HashSet.h>
57#include <wtf/RefCountedArray.h>
58#include <wtf/SimpleStats.h>
59#include <wtf/StackBounds.h>
60#include <wtf/ThreadSafeRefCounted.h>
61#include <wtf/ThreadSpecific.h>
62#include <wtf/WTFThreadData.h>
63#include <wtf/text/WTFString.h>
64#if ENABLE(REGEXP_TRACING)
65#include <wtf/ListHashSet.h>
66#endif
67
68namespace JSC {
69
70    class ArityCheckFailReturnThunks;
71    class BuiltinExecutables;
72    class CodeBlock;
73    class CodeCache;
74    class CommonIdentifiers;
75    class ExecState;
76    class HandleStack;
77    class Identifier;
78    class Interpreter;
79    class JSGlobalObject;
80    class JSObject;
81    class Keywords;
82    class LLIntOffsetsExtractor;
83    class LegacyProfiler;
84    class NativeExecutable;
85    class ParserArena;
86    class RegExpCache;
87    class SourceProvider;
88    class SourceProviderCache;
89    struct StackFrame;
90    class Stringifier;
91    class Structure;
92#if ENABLE(REGEXP_TRACING)
93    class RegExp;
94#endif
95    class UnlinkedCodeBlock;
96    class UnlinkedEvalCodeBlock;
97    class UnlinkedFunctionExecutable;
98    class UnlinkedProgramCodeBlock;
99    class VMEntryScope;
100    class Watchpoint;
101    class WatchpointSet;
102
103#if ENABLE(DFG_JIT)
104    namespace DFG {
105    class LongLivedState;
106    }
107#endif // ENABLE(DFG_JIT)
108#if ENABLE(FTL_JIT)
109    namespace FTL {
110    class Thunks;
111    }
112#endif // ENABLE(FTL_JIT)
113    namespace CommonSlowPaths {
114    struct ArityCheckData;
115    }
116    namespace Profiler {
117    class Database;
118    }
119
120    struct HashTable;
121    struct Instruction;
122
123    struct LocalTimeOffsetCache {
124        LocalTimeOffsetCache()
125            : start(0.0)
126            , end(-1.0)
127            , increment(0.0)
128        {
129        }
130
131        void reset()
132        {
133            offset = LocalTimeOffset();
134            start = 0.0;
135            end = -1.0;
136            increment = 0.0;
137        }
138
139        LocalTimeOffset offset;
140        double start;
141        double end;
142        double increment;
143    };
144
145    class ConservativeRoots;
146
147#if COMPILER(MSVC)
148#pragma warning(push)
149#pragma warning(disable: 4200) // Disable "zero-sized array in struct/union" warning
150#endif
151    struct ScratchBuffer {
152        ScratchBuffer()
153        {
154            u.m_activeLength = 0;
155        }
156
157        static ScratchBuffer* create(size_t size)
158        {
159            ScratchBuffer* result = new (fastMalloc(ScratchBuffer::allocationSize(size))) ScratchBuffer;
160
161            return result;
162        }
163
164        static size_t allocationSize(size_t bufferSize) { return sizeof(ScratchBuffer) + bufferSize; }
165        void setActiveLength(size_t activeLength) { u.m_activeLength = activeLength; }
166        size_t activeLength() const { return u.m_activeLength; };
167        size_t* activeLengthPtr() { return &u.m_activeLength; };
168        void* dataBuffer() { return m_buffer; }
169
170        union {
171            size_t m_activeLength;
172            double pad; // Make sure m_buffer is double aligned.
173        } u;
174#if CPU(MIPS) && (defined WTF_MIPS_ARCH_REV && WTF_MIPS_ARCH_REV == 2)
175        void* m_buffer[0] __attribute__((aligned(8)));
176#else
177        void* m_buffer[0];
178#endif
179    };
180#if COMPILER(MSVC)
181#pragma warning(pop)
182#endif
183
184    class VM : public ThreadSafeRefCounted<VM> {
185    public:
186        // WebCore has a one-to-one mapping of threads to VMs;
187        // either create() or createLeaked() should only be called once
188        // on a thread, this is the 'default' VM (it uses the
189        // thread's default string uniquing table from wtfThreadData).
190        // API contexts created using the new context group aware interface
191        // create APIContextGroup objects which require less locking of JSC
192        // than the old singleton APIShared VM created for use by
193        // the original API.
194        enum VMType { Default, APIContextGroup, APIShared };
195
196        struct ClientData {
197            JS_EXPORT_PRIVATE virtual ~ClientData() = 0;
198        };
199
200        bool isSharedInstance() { return vmType == APIShared; }
201        bool usingAPI() { return vmType != Default; }
202        JS_EXPORT_PRIVATE static bool sharedInstanceExists();
203        JS_EXPORT_PRIVATE static VM& sharedInstance();
204
205        JS_EXPORT_PRIVATE static PassRefPtr<VM> create(HeapType = SmallHeap);
206        JS_EXPORT_PRIVATE static PassRefPtr<VM> createLeaked(HeapType = SmallHeap);
207        static PassRefPtr<VM> createContextGroup(HeapType = SmallHeap);
208        JS_EXPORT_PRIVATE ~VM();
209
210        void makeUsableFromMultipleThreads() { heap.machineThreads().makeUsableFromMultipleThreads(); }
211
212    private:
213        RefPtr<JSLock> m_apiLock;
214
215    public:
216#if ENABLE(ASSEMBLER)
217        // executableAllocator should be destructed after the heap, as the heap can call executableAllocator
218        // in its destructor.
219        ExecutableAllocator executableAllocator;
220#endif
221
222        // The heap should be just after executableAllocator and before other members to ensure that it's
223        // destructed after all the objects that reference it.
224        Heap heap;
225
226#if ENABLE(DFG_JIT)
227        OwnPtr<DFG::LongLivedState> dfgState;
228#endif // ENABLE(DFG_JIT)
229
230        VMType vmType;
231        ClientData* clientData;
232        ExecState* topCallFrame;
233        std::unique_ptr<Watchdog> watchdog;
234
235        const OwnPtr<const HashTable> arrayConstructorTable;
236        const OwnPtr<const HashTable> arrayPrototypeTable;
237        const OwnPtr<const HashTable> booleanPrototypeTable;
238        const OwnPtr<const HashTable> dataViewTable;
239        const OwnPtr<const HashTable> dateTable;
240        const OwnPtr<const HashTable> dateConstructorTable;
241        const OwnPtr<const HashTable> errorPrototypeTable;
242        const OwnPtr<const HashTable> globalObjectTable;
243        const OwnPtr<const HashTable> jsonTable;
244        const OwnPtr<const HashTable> numberConstructorTable;
245        const OwnPtr<const HashTable> numberPrototypeTable;
246        const OwnPtr<const HashTable> objectConstructorTable;
247        const OwnPtr<const HashTable> privateNamePrototypeTable;
248        const OwnPtr<const HashTable> regExpTable;
249        const OwnPtr<const HashTable> regExpConstructorTable;
250        const OwnPtr<const HashTable> regExpPrototypeTable;
251        const OwnPtr<const HashTable> stringConstructorTable;
252#if ENABLE(PROMISES)
253        const OwnPtr<const HashTable> promisePrototypeTable;
254        const OwnPtr<const HashTable> promiseConstructorTable;
255#endif
256
257        Strong<Structure> structureStructure;
258        Strong<Structure> structureRareDataStructure;
259        Strong<Structure> debuggerActivationStructure;
260        Strong<Structure> terminatedExecutionErrorStructure;
261        Strong<Structure> stringStructure;
262        Strong<Structure> notAnObjectStructure;
263        Strong<Structure> propertyNameIteratorStructure;
264        Strong<Structure> getterSetterStructure;
265        Strong<Structure> customGetterSetterStructure;
266        Strong<Structure> apiWrapperStructure;
267        Strong<Structure> JSScopeStructure;
268        Strong<Structure> executableStructure;
269        Strong<Structure> nativeExecutableStructure;
270        Strong<Structure> evalExecutableStructure;
271        Strong<Structure> programExecutableStructure;
272        Strong<Structure> functionExecutableStructure;
273        Strong<Structure> regExpStructure;
274        Strong<Structure> symbolTableStructure;
275        Strong<Structure> structureChainStructure;
276        Strong<Structure> sparseArrayValueMapStructure;
277        Strong<Structure> arrayBufferNeuteringWatchpointStructure;
278        Strong<Structure> withScopeStructure;
279        Strong<Structure> unlinkedFunctionExecutableStructure;
280        Strong<Structure> unlinkedProgramCodeBlockStructure;
281        Strong<Structure> unlinkedEvalCodeBlockStructure;
282        Strong<Structure> unlinkedFunctionCodeBlockStructure;
283        Strong<Structure> propertyTableStructure;
284        Strong<Structure> mapDataStructure;
285        Strong<Structure> weakMapDataStructure;
286#if ENABLE(PROMISES)
287        Strong<Structure> promiseDeferredStructure;
288        Strong<Structure> promiseReactionStructure;
289#endif
290        Strong<JSCell> iterationTerminator;
291
292        AtomicStringTable* m_atomicStringTable;
293        CommonIdentifiers* propertyNames;
294        const MarkedArgumentBuffer* emptyList; // Lists are supposed to be allocated on the stack to have their elements properly marked, which is not the case here - but this list has nothing to mark.
295        SmallStrings smallStrings;
296        NumericStrings numericStrings;
297        DateInstanceCache dateInstanceCache;
298        WTF::SimpleStats machineCodeBytesPerBytecodeWordForBaselineJIT;
299        WeakGCMap<StringImpl*, JSString, PtrHash<StringImpl*>> stringCache;
300        Strong<JSString> lastCachedString;
301
302        AtomicStringTable* atomicStringTable() const { return m_atomicStringTable; }
303
304        void setInDefineOwnProperty(bool inDefineOwnProperty)
305        {
306            m_inDefineOwnProperty = inDefineOwnProperty;
307        }
308
309        bool isInDefineOwnProperty()
310        {
311            return m_inDefineOwnProperty;
312        }
313
314        LegacyProfiler* enabledProfiler() { return m_enabledProfiler; }
315        void setEnabledProfiler(LegacyProfiler*);
316
317        void* enabledProfilerAddress() { return &m_enabledProfiler; }
318
319#if ENABLE(JIT)
320        bool canUseJIT() { return m_canUseJIT; }
321#else
322        bool canUseJIT() { return false; } // interpreter only
323#endif
324
325#if ENABLE(YARR_JIT)
326        bool canUseRegExpJIT() { return m_canUseRegExpJIT; }
327#else
328        bool canUseRegExpJIT() { return false; } // interpreter only
329#endif
330
331        SourceProviderCache* addSourceProviderCache(SourceProvider*);
332        void clearSourceProviderCaches();
333
334        PrototypeMap prototypeMap;
335
336        OwnPtr<ParserArena> parserArena;
337        typedef HashMap<RefPtr<SourceProvider>, RefPtr<SourceProviderCache>> SourceProviderCacheMap;
338        SourceProviderCacheMap sourceProviderCacheMap;
339        OwnPtr<Keywords> keywords;
340        Interpreter* interpreter;
341#if ENABLE(JIT)
342        OwnPtr<JITThunks> jitStubs;
343        MacroAssemblerCodeRef getCTIStub(ThunkGenerator generator)
344        {
345            return jitStubs->ctiStub(this, generator);
346        }
347        NativeExecutable* getHostFunction(NativeFunction, Intrinsic);
348
349        std::unique_ptr<ArityCheckFailReturnThunks> arityCheckFailReturnThunks;
350#endif // ENABLE(JIT)
351        std::unique_ptr<CommonSlowPaths::ArityCheckData> arityCheckData;
352#if ENABLE(FTL_JIT)
353        std::unique_ptr<FTL::Thunks> ftlThunks;
354#endif
355        NativeExecutable* getHostFunction(NativeFunction, NativeFunction constructor);
356
357        static ptrdiff_t exceptionOffset()
358        {
359            return OBJECT_OFFSETOF(VM, m_exception);
360        }
361
362        static ptrdiff_t callFrameForThrowOffset()
363        {
364            return OBJECT_OFFSETOF(VM, callFrameForThrow);
365        }
366
367        static ptrdiff_t targetMachinePCForThrowOffset()
368        {
369            return OBJECT_OFFSETOF(VM, targetMachinePCForThrow);
370        }
371
372        JS_EXPORT_PRIVATE void clearException();
373        JS_EXPORT_PRIVATE void clearExceptionStack();
374        void getExceptionInfo(JSValue& exception, RefCountedArray<StackFrame>& exceptionStack);
375        void setExceptionInfo(JSValue& exception, RefCountedArray<StackFrame>& exceptionStack);
376        JSValue exception() const { return m_exception; }
377        JSValue* addressOfException() { return &m_exception; }
378        const RefCountedArray<StackFrame>& exceptionStack() const { return m_exceptionStack; }
379
380        JS_EXPORT_PRIVATE JSValue throwException(ExecState*, JSValue);
381        JS_EXPORT_PRIVATE JSObject* throwException(ExecState*, JSObject*);
382
383        void* stackPointerAtVMEntry() const { return m_stackPointerAtVMEntry; }
384        void setStackPointerAtVMEntry(void*);
385
386        size_t reservedZoneSize() const { return m_reservedZoneSize; }
387        size_t updateReservedZoneSize(size_t reservedZoneSize);
388
389#if ENABLE(FTL_JIT)
390        void updateFTLLargestStackSize(size_t);
391        void** addressOfFTLStackLimit() { return &m_ftlStackLimit; }
392#endif
393
394#if !ENABLE(JIT)
395        void* jsStackLimit() { return m_jsStackLimit; }
396        void setJSStackLimit(void* limit) { m_jsStackLimit = limit; }
397#endif
398        void* stackLimit() { return m_stackLimit; }
399        void** addressOfStackLimit() { return &m_stackLimit; }
400
401        bool isSafeToRecurse(size_t neededStackInBytes = 0) const
402        {
403            ASSERT(wtfThreadData().stack().isGrowingDownward());
404            int8_t* curr = reinterpret_cast<int8_t*>(&curr);
405            int8_t* limit = reinterpret_cast<int8_t*>(m_stackLimit);
406            return curr >= limit && static_cast<size_t>(curr - limit) >= neededStackInBytes;
407        }
408
409        void* lastStackTop() { return m_lastStackTop; }
410        void setLastStackTop(void* lastStackTop) { m_lastStackTop = lastStackTop; }
411
412        const ClassInfo* const jsArrayClassInfo;
413        const ClassInfo* const jsFinalObjectClassInfo;
414
415        JSValue hostCallReturnValue;
416        ExecState* newCallFrameReturnValue;
417        ExecState* callFrameForThrow;
418        void* targetMachinePCForThrow;
419        Instruction* targetInterpreterPCForThrow;
420        uint32_t osrExitIndex;
421        void* osrExitJumpDestination;
422        Vector<ScratchBuffer*> scratchBuffers;
423        size_t sizeOfLastScratchBuffer;
424
425        ScratchBuffer* scratchBufferForSize(size_t size)
426        {
427            if (!size)
428                return 0;
429
430            if (size > sizeOfLastScratchBuffer) {
431                // Protect against a N^2 memory usage pathology by ensuring
432                // that at worst, we get a geometric series, meaning that the
433                // total memory usage is somewhere around
434                // max(scratch buffer size) * 4.
435                sizeOfLastScratchBuffer = size * 2;
436
437                ScratchBuffer* newBuffer = ScratchBuffer::create(sizeOfLastScratchBuffer);
438                RELEASE_ASSERT(newBuffer);
439                scratchBuffers.append(newBuffer);
440            }
441
442            ScratchBuffer* result = scratchBuffers.last();
443            result->setActiveLength(0);
444            return result;
445        }
446
447        void gatherConservativeRoots(ConservativeRoots&);
448
449        VMEntryScope* entryScope;
450
451        HashSet<JSObject*> stringRecursionCheckVisitedObjects;
452
453        LocalTimeOffsetCache localTimeOffsetCache;
454
455        String cachedDateString;
456        double cachedDateStringValue;
457
458        OwnPtr<Profiler::Database> m_perBytecodeProfiler;
459        RefPtr<TypedArrayController> m_typedArrayController;
460        RegExpCache* m_regExpCache;
461        BumpPointerAllocator m_regExpAllocator;
462
463#if ENABLE(REGEXP_TRACING)
464        typedef ListHashSet<RegExp*> RTTraceList;
465        RTTraceList* m_rtTraceList;
466#endif
467
468        bool hasExclusiveThread() const { return m_apiLock->hasExclusiveThread(); }
469        std::thread::id exclusiveThread() const { return m_apiLock->exclusiveThread(); }
470        void setExclusiveThread(std::thread::id threadId) { m_apiLock->setExclusiveThread(threadId); }
471
472        JS_EXPORT_PRIVATE void resetDateCache();
473
474        JS_EXPORT_PRIVATE void startSampling();
475        JS_EXPORT_PRIVATE void stopSampling();
476        JS_EXPORT_PRIVATE void dumpSampleData(ExecState* exec);
477        RegExpCache* regExpCache() { return m_regExpCache; }
478#if ENABLE(REGEXP_TRACING)
479        void addRegExpToTrace(RegExp*);
480#endif
481        JS_EXPORT_PRIVATE void dumpRegExpTrace();
482
483        bool isCollectorBusy() { return heap.isBusy(); }
484        JS_EXPORT_PRIVATE void releaseExecutableMemory();
485
486#if ENABLE(GC_VALIDATION)
487        bool isInitializingObject() const;
488        void setInitializingObjectClass(const ClassInfo*);
489#endif
490
491        unsigned m_newStringsSinceLastHashCons;
492
493        static const unsigned s_minNumberOfNewStringsToHashCons = 100;
494
495        bool haveEnoughNewStringsToHashCons() { return m_newStringsSinceLastHashCons > s_minNumberOfNewStringsToHashCons; }
496        void resetNewStringsSinceLastHashCons() { m_newStringsSinceLastHashCons = 0; }
497
498        bool currentThreadIsHoldingAPILock() const { return m_apiLock->currentThreadIsHoldingLock(); }
499
500        JSLock& apiLock() { return *m_apiLock; }
501        CodeCache* codeCache() { return m_codeCache.get(); }
502
503        void waitForCompilationsToComplete();
504
505        JS_EXPORT_PRIVATE void discardAllCode();
506
507        void registerWatchpointForImpureProperty(const Identifier&, Watchpoint*);
508        // FIXME: Use AtomicString once it got merged with Identifier.
509        JS_EXPORT_PRIVATE void addImpureProperty(const String&);
510
511        BuiltinExecutables* builtinExecutables() { return m_builtinExecutables.get(); }
512
513    private:
514        friend class LLIntOffsetsExtractor;
515        friend class ClearExceptionScope;
516        friend class RecursiveAllocationScope;
517
518        VM(VMType, HeapType);
519        static VM*& sharedInstanceInternal();
520        void createNativeThunk();
521
522        void updateStackLimit();
523
524#if ENABLE(ASSEMBLER)
525        bool m_canUseAssembler;
526#endif
527#if ENABLE(JIT)
528        bool m_canUseJIT;
529#endif
530#if ENABLE(YARR_JIT)
531        bool m_canUseRegExpJIT;
532#endif
533#if ENABLE(GC_VALIDATION)
534        const ClassInfo* m_initializingObjectClass;
535#endif
536        void* m_stackPointerAtVMEntry;
537        size_t m_reservedZoneSize;
538#if !ENABLE(JIT)
539        struct {
540            void* m_stackLimit;
541            void* m_jsStackLimit;
542        };
543#else
544        union {
545            void* m_stackLimit;
546            void* m_jsStackLimit;
547        };
548#if ENABLE(FTL_JIT)
549        void* m_ftlStackLimit;
550        size_t m_largestFTLStackSize;
551#endif
552#endif
553        void* m_lastStackTop;
554        JSValue m_exception;
555        bool m_inDefineOwnProperty;
556        OwnPtr<CodeCache> m_codeCache;
557        LegacyProfiler* m_enabledProfiler;
558        OwnPtr<BuiltinExecutables> m_builtinExecutables;
559        RefCountedArray<StackFrame> m_exceptionStack;
560        HashMap<String, RefPtr<WatchpointSet>> m_impurePropertyWatchpointSets;
561    };
562
563#if ENABLE(GC_VALIDATION)
564    inline bool VM::isInitializingObject() const
565    {
566        return !!m_initializingObjectClass;
567    }
568
569    inline void VM::setInitializingObjectClass(const ClassInfo* initializingObjectClass)
570    {
571        m_initializingObjectClass = initializingObjectClass;
572    }
573#endif
574
575    inline Heap* WeakSet::heap() const
576    {
577        return &m_vm->heap;
578    }
579
580#if ENABLE(JIT)
581    extern "C" void sanitizeStackForVMImpl(VM*);
582#endif
583
584    void sanitizeStackForVM(VM*);
585    void logSanitizeStack(VM*);
586
587} // namespace JSC
588
589#endif // VM_h
590