DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Implementation

Mercurial (777e60ca8853)

VCS Links

Line Code
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
/* -*- 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 jsiter_h
#define jsiter_h

/*
 * JavaScript iterators.
 */

#include "mozilla/MemoryReporting.h"

#include "jscntxt.h"

#include "gc/Barrier.h"
#include "vm/Stack.h"

/*
 * For cacheable native iterators, whether the iterator is currently active.
 * Not serialized by XDR.
 */
#define JSITER_ACTIVE       0x1000
#define JSITER_UNREUSABLE   0x2000

namespace js {

struct NativeIterator
{
    HeapPtrObject obj;                  // Object being iterated.
    JSObject* iterObj_;                 // Internal iterator object.
    HeapPtr<JSFlatString>* props_array;
    HeapPtr<JSFlatString>* props_cursor;
    HeapPtr<JSFlatString>* props_end;
    Shape** shapes_array;
    uint32_t shapes_length;
    uint32_t shapes_key;
    uint32_t flags;

  private:
    /* While in compartment->enumerators, these form a doubly linked list. */
    NativeIterator* next_;
    NativeIterator* prev_;

  public:
    bool isKeyIter() const {
        return (flags & JSITER_FOREACH) == 0;
    }

    inline HeapPtr<JSFlatString>* begin() const {
        return props_array;
    }

    inline HeapPtr<JSFlatString>* end() const {
        return props_end;
    }

    size_t numKeys() const {
        return end() - begin();
    }

    JSObject* iterObj() const {
        return iterObj_;
    }
    HeapPtr<JSFlatString>* current() const {
        JS_ASSERT(props_cursor < props_end);
        return props_cursor;
    }

    NativeIterator* next() {
        return next_;
    }

    static inline size_t offsetOfNext() {
        return offsetof(NativeIterator, next_);
    }
    static inline size_t offsetOfPrev() {
        return offsetof(NativeIterator, prev_);
    }

    void incCursor() {
        props_cursor = props_cursor + 1;
    }
    void link(NativeIterator* other) {
        /* A NativeIterator cannot appear in the enumerator list twice. */
        JS_ASSERT(!next_ && !prev_);
        JS_ASSERT(flags & JSITER_ENUMERATE);

        this->next_ = other;
        this->prev_ = other->prev_;
        other->prev_->next_ = this;
        other->prev_ = this;
    }
    void unlink() {
        JS_ASSERT(flags & JSITER_ENUMERATE);

        next_->prev_ = prev_;
        prev_->next_ = next_;
        next_ = nullptr;
        prev_ = nullptr;
    }

    static NativeIterator* allocateSentinel(JSContext* cx);
    static NativeIterator* allocateIterator(JSContext* cx, uint32_t slength,
                                            const js::AutoIdVector& props);
    void init(JSObject* obj, JSObject* iterObj, unsigned flags, uint32_t slength, uint32_t key);

    void mark(JSTracer* trc);

    static void destroy(NativeIterator* iter) {
        js_free(iter);
    }
};

class PropertyIteratorObject : public JSObject
{
  public:
    static const Class class_;

    NativeIterator* getNativeIterator() const {
        return static_cast<js::NativeIterator*>(getPrivate());
    }
    void setNativeIterator(js::NativeIterator* ni) {
        setPrivate(ni);
    }

    size_t sizeOfMisc(mozilla::MallocSizeOf mallocSizeOf) const;

  private:
    static void trace(JSTracer* trc, JSObject* obj);
    static void finalize(FreeOp* fop, JSObject* obj);
};

class ArrayIteratorObject : public JSObject
{
  public:
    static const Class class_;
};

class StringIteratorObject : public JSObject
{
  public:
    static const Class class_;
};

bool
VectorToIdArray(JSContext* cx, AutoIdVector& props, JSIdArray** idap);

bool
GetIterator(JSContext* cx, HandleObject obj, unsigned flags, MutableHandleValue vp);

JSObject*
GetIteratorObject(JSContext* cx, HandleObject obj, unsigned flags);

bool
VectorToKeyIterator(JSContext* cx, HandleObject obj, unsigned flags, AutoIdVector& props,
                    MutableHandleValue vp);

bool
VectorToValueIterator(JSContext* cx, HandleObject obj, unsigned flags, AutoIdVector& props,
                      MutableHandleValue vp);

/*
 * Creates either a key or value iterator, depending on flags. For a value
 * iterator, performs value-lookup to convert the given list of jsids.
 */
bool
EnumeratedIdVectorToIterator(JSContext* cx, HandleObject obj, unsigned flags, AutoIdVector& props,
                             MutableHandleValue vp);

/*
 * Convert the value stored in *vp to its iteration object. The flags should
 * contain JSITER_ENUMERATE if js::ValueToIterator is called when enumerating
 * for-in semantics are required, and when the caller can guarantee that the
 * iterator will never be exposed to scripts.
 */
bool
ValueToIterator(JSContext* cx, unsigned flags, MutableHandleValue vp);

bool
CloseIterator(JSContext* cx, HandleObject iterObj);

bool
UnwindIteratorForException(JSContext* cx, js::HandleObject obj);

void
UnwindIteratorForUncatchableException(JSContext* cx, JSObject* obj);

bool
IteratorConstructor(JSContext* cx, unsigned argc, Value* vp);

} /* namespace js */

extern bool
js_SuppressDeletedProperty(JSContext* cx, js::HandleObject obj, jsid id);

extern bool
js_SuppressDeletedElement(JSContext* cx, js::HandleObject obj, uint32_t index);

extern bool
js_SuppressDeletedElements(JSContext* cx, js::HandleObject obj, uint32_t begin, uint32_t end);

/*
 * IteratorMore() indicates whether another value is available. It might
 * internally call iterobj.next() and then cache the value until its
 * picked up by IteratorNext(). The value is cached in the current context.
 */
extern bool
js_IteratorMore(JSContext* cx, js::HandleObject iterobj, js::MutableHandleValue rval);

extern bool
js_IteratorNext(JSContext* cx, js::HandleObject iterobj, js::MutableHandleValue rval);

extern bool
js_ThrowStopIteration(JSContext* cx);

namespace js {

/*
 * Create an object of the form { value: VALUE, done: DONE }.
 * ES6 draft from 2013-09-05, section 25.4.3.4.
 */
extern JSObject*
CreateItrResultObject(JSContext* cx, js::HandleValue value, bool done);

} /* namespace js */

/*
 * Generator state codes.
 */
enum JSGeneratorState
{
    JSGEN_NEWBORN,  /* not yet started */
    JSGEN_OPEN,     /* started by a .next() or .send(undefined) call */
    JSGEN_RUNNING,  /* currently executing via .next(), etc., call */
    JSGEN_CLOSING,  /* close method is doing asynchronous return */
    JSGEN_CLOSED    /* closed, cannot be started or closed again */
};

struct JSGenerator
{
    js::HeapPtrObject    obj;
    JSGeneratorState     state;
    js::InterpreterRegs  regs;
    JSGenerator*         prevGenerator;
    js::InterpreterFrame* fp;
    js::HeapValue        stackSnapshot[1];
};

extern JSObject*
js_NewGenerator(JSContext* cx, const js::InterpreterRegs& regs);

extern JSObject*
js_InitIteratorClasses(JSContext* cx, js::HandleObject obj);

#endif /* jsiter_h */