C++ HandleString类代码示例

bool
CharCodeAt(JSContext *cx, HandleString str, int32_t index, uint32_t *code)
{
    JS_ASSERT(index >= 0 &&
              static_cast<uint32_t>(index) < str->length());

    const jschar *chars = str->getChars(cx);
    if (!chars)
        return false;

    *code = chars[index];
    return true;
}

bool
js::CreateRegExpMatchResult(JSContext *cx, HandleString string, MatchPairs &matches, Value *rval)
{
    Rooted<JSStableString*> input(cx, string->ensureStable(cx));
    if (!input)
        return false;
    return CreateRegExpMatchResult(cx, input, input->chars(), input->length(), matches, rval);
}

bool
CharCodeAt(JSContext *cx, HandleString str, int32_t index, uint32_t *code)
{
    jschar c;
    if (!str->getChar(cx, index, &c))
        return false;
    *code = c;
    return true;
}

bool
js::DirectEvalStringFromIon(JSContext *cx,
                            HandleObject scopeobj, HandleScript callerScript,
                            HandleValue thisValue, HandleString str,
                            jsbytecode *pc, MutableHandleValue vp)
{
    AssertInnerizedScopeChain(cx, *scopeobj);

    Rooted<GlobalObject*> scopeObjGlobal(cx, &scopeobj->global());
    if (!GlobalObject::isRuntimeCodeGenEnabled(cx, scopeObjGlobal)) {
        JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_CSP_BLOCKED_EVAL);
        return false;
    }

    // ES5 15.1.2.1 steps 2-8.

    unsigned staticLevel = callerScript->staticLevel() + 1;

    Rooted<JSFlatString*> flatStr(cx, str->ensureFlat(cx));
    if (!flatStr)
        return false;

    EvalJSONResult ejr = TryEvalJSON(cx, callerScript, flatStr, vp);
    if (ejr != EvalJSON_NotJSON)
        return ejr == EvalJSON_Success;

    EvalScriptGuard esg(cx);

    esg.lookupInEvalCache(flatStr, callerScript, pc);

    if (!esg.foundScript()) {
        RootedScript maybeScript(cx);
        const char *filename;
        unsigned lineno;
        JSPrincipals *originPrincipals;
        uint32_t pcOffset;
        DescribeScriptedCallerForCompilation(cx, &maybeScript, &filename, &lineno, &pcOffset,
                                              &originPrincipals, CALLED_FROM_JSOP_EVAL);

        const char *introducerFilename = filename;
        if (maybeScript && maybeScript->scriptSource()->introducerFilename())
            introducerFilename = maybeScript->scriptSource()->introducerFilename();

        CompileOptions options(cx);
        options.setFileAndLine(filename, 1)
               .setCompileAndGo(true)
               .setForEval(true)
               .setNoScriptRval(false)
               .setOriginPrincipals(originPrincipals)
               .setIntroductionInfo(introducerFilename, "eval", lineno, maybeScript, pcOffset);

        AutoStableStringChars flatChars(cx);
        if (!flatChars.initTwoByte(cx, flatStr))
            return false;

        const char16_t *chars = flatChars.twoByteRange().start().get();
        SourceBufferHolder::Ownership ownership = flatChars.maybeGiveOwnershipToCaller()
                                                  ? SourceBufferHolder::GiveOwnership
                                                  : SourceBufferHolder::NoOwnership;
        SourceBufferHolder srcBuf(chars, flatStr->length(), ownership);
        JSScript *compiled = frontend::CompileScript(cx, &cx->tempLifoAlloc(),
                                                     scopeobj, callerScript, options,
                                                     srcBuf, flatStr, staticLevel);
        if (!compiled)
            return false;

        esg.setNewScript(compiled);
    }

    // Primitive 'this' values should have been filtered out by Ion. If boxed,
    // the calling frame cannot be updated to store the new object.
    JS_ASSERT(thisValue.isObject() || thisValue.isUndefined() || thisValue.isNull());

    return ExecuteKernel(cx, esg.script(), *scopeobj, thisValue, ExecuteType(DIRECT_EVAL),
                         NullFramePtr() /* evalInFrame */, vp.address());
}

bool
js::DirectEvalStringFromIon(JSContext* cx,
                            HandleObject scopeObj, HandleScript callerScript,
                            HandleValue newTargetValue, HandleString str,
                            jsbytecode* pc, MutableHandleValue vp)
{
    AssertInnerizedScopeChain(cx, *scopeObj);

    Rooted<GlobalObject*> scopeObjGlobal(cx, &scopeObj->global());
    if (!GlobalObject::isRuntimeCodeGenEnabled(cx, scopeObjGlobal)) {
        JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_CSP_BLOCKED_EVAL);
        return false;
    }

    // ES5 15.1.2.1 steps 2-8.

    RootedLinearString linearStr(cx, str->ensureLinear(cx));
    if (!linearStr)
        return false;

    EvalJSONResult ejr = TryEvalJSON(cx, linearStr, vp);
    if (ejr != EvalJSON_NotJSON)
        return ejr == EvalJSON_Success;

    EvalScriptGuard esg(cx);

    esg.lookupInEvalCache(linearStr, callerScript, pc);

    if (!esg.foundScript()) {
        RootedScript maybeScript(cx);
        const char* filename;
        unsigned lineno;
        bool mutedErrors;
        uint32_t pcOffset;
        DescribeScriptedCallerForCompilation(cx, &maybeScript, &filename, &lineno, &pcOffset,
                                             &mutedErrors, CALLED_FROM_JSOP_EVAL);

        const char* introducerFilename = filename;
        if (maybeScript && maybeScript->scriptSource()->introducerFilename())
            introducerFilename = maybeScript->scriptSource()->introducerFilename();

        RootedObject enclosing(cx, callerScript->innermostStaticScope(pc));
        Rooted<StaticEvalScope*> staticScope(cx, StaticEvalScope::create(cx, enclosing));
        if (!staticScope)
            return false;

        CompileOptions options(cx);
        options.setIsRunOnce(true)
               .setForEval(true)
               .setNoScriptRval(false)
               .setMutedErrors(mutedErrors)
               .maybeMakeStrictMode(IsStrictEvalPC(pc));

        if (introducerFilename) {
            options.setFileAndLine(filename, 1);
            options.setIntroductionInfo(introducerFilename, "eval", lineno, maybeScript, pcOffset);
        } else {
            options.setFileAndLine("eval", 1);
            options.setIntroductionType("eval");
        }

        AutoStableStringChars linearChars(cx);
        if (!linearChars.initTwoByte(cx, linearStr))
            return false;

        const char16_t* chars = linearChars.twoByteRange().start().get();
        SourceBufferHolder::Ownership ownership = linearChars.maybeGiveOwnershipToCaller()
                                                  ? SourceBufferHolder::GiveOwnership
                                                  : SourceBufferHolder::NoOwnership;
        SourceBufferHolder srcBuf(chars, linearStr->length(), ownership);
        JSScript* compiled = frontend::CompileScript(cx, &cx->tempLifoAlloc(),
                                                     scopeObj, staticScope, callerScript,
                                                     options, srcBuf, linearStr);
        if (!compiled)
            return false;

        if (compiled->strict())
            staticScope->setStrict();

        esg.setNewScript(compiled);
    }

    return ExecuteKernel(cx, esg.script(), *scopeObj, newTargetValue,
                         NullFramePtr() /* evalInFrame */, vp.address());
}

bool
js::DirectEvalFromIon(JSContext *cx,
                      HandleObject scopeobj, HandleScript callerScript,
                      HandleValue thisValue, HandleString str,
                      MutableHandleValue vp)
{
    AssertInnerizedScopeChain(cx, *scopeobj);

    Rooted<GlobalObject*> scopeObjGlobal(cx, &scopeobj->global());
    if (!GlobalObject::isRuntimeCodeGenEnabled(cx, scopeObjGlobal)) {
        JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_CSP_BLOCKED_EVAL);
        return false;
    }

    // ES5 15.1.2.1 steps 2-8.

    unsigned staticLevel = callerScript->staticLevel + 1;

    Rooted<JSStableString*> stableStr(cx, str->ensureStable(cx));
    if (!stableStr)
        return false;

    StableCharPtr chars = stableStr->chars();
    size_t length = stableStr->length();

    EvalJSONResult ejr = TryEvalJSON(cx, callerScript, chars, length, vp);
    if (ejr != EvalJSON_NotJSON)
        return ejr == EvalJSON_Success;

    EvalScriptGuard esg(cx);

    // Ion will not perform cross compartment direct eval calls.
    JSPrincipals *principals = cx->compartment->principals;

    esg.lookupInEvalCache(stableStr, callerScript->function(), staticLevel);

    if (!esg.foundScript()) {
        unsigned lineno;
        const char *filename;
        JSPrincipals *originPrincipals;
        CurrentScriptFileLineOrigin(cx, &filename, &lineno, &originPrincipals,
                                    CALLED_FROM_JSOP_EVAL);

        CompileOptions options(cx);
        options.setFileAndLine(filename, lineno)
               .setCompileAndGo(true)
               .setNoScriptRval(false)
               .setPrincipals(principals)
               .setOriginPrincipals(originPrincipals);
        UnrootedScript compiled = frontend::CompileScript(cx, scopeobj, callerScript, options,
                                                          chars.get(), length, stableStr, staticLevel);
        if (!compiled)
            return false;

        esg.setNewScript(compiled);
    }

    // Primitive 'this' values should have been filtered out by Ion. If boxed,
    // the calling frame cannot be updated to store the new object.
    JS_ASSERT(thisValue.isObject() || thisValue.isUndefined() || thisValue.isNull());

    return ExecuteKernel(cx, esg.script(), *scopeobj, thisValue, ExecuteType(DIRECT_EVAL),
                         NullFramePtr() /* evalInFrame */, vp.address());
}

bool
js::DirectEvalStringFromIon(JSContext* cx,
                            HandleObject scopeobj, HandleScript callerScript,
                            HandleValue thisValue, HandleValue newTargetValue,
                            HandleString str, jsbytecode* pc, MutableHandleValue vp)
{
    AssertInnerizedScopeChain(cx, *scopeobj);

    Rooted<GlobalObject*> scopeObjGlobal(cx, &scopeobj->global());
    if (!GlobalObject::isRuntimeCodeGenEnabled(cx, scopeObjGlobal)) {
        JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_CSP_BLOCKED_EVAL);
        return false;
    }

    // ES5 15.1.2.1 steps 2-8.

    unsigned staticLevel = callerScript->staticLevel() + 1;

    RootedLinearString linearStr(cx, str->ensureLinear(cx));
    if (!linearStr)
        return false;

    EvalJSONResult ejr = TryEvalJSON(cx, linearStr, vp);
    if (ejr != EvalJSON_NotJSON)
        return ejr == EvalJSON_Success;

    EvalScriptGuard esg(cx);

    esg.lookupInEvalCache(linearStr, callerScript, pc);

    if (!esg.foundScript()) {
        RootedScript maybeScript(cx);
        const char* filename;
        unsigned lineno;
        bool mutedErrors;
        uint32_t pcOffset;
        DescribeScriptedCallerForCompilation(cx, &maybeScript, &filename, &lineno, &pcOffset,
                                             &mutedErrors, CALLED_FROM_JSOP_EVAL);

        const char* introducerFilename = filename;
        if (maybeScript && maybeScript->scriptSource()->introducerFilename())
            introducerFilename = maybeScript->scriptSource()->introducerFilename();

        RootedObject enclosing(cx, callerScript->innermostStaticScope(pc));
        Rooted<StaticEvalObject*> staticScope(cx, StaticEvalObject::create(cx, enclosing));
        if (!staticScope)
            return false;

        CompileOptions options(cx);
        options.setFileAndLine(filename, 1)
               .setIsRunOnce(true)
               .setForEval(true)
               .setNoScriptRval(false)
               .setMutedErrors(mutedErrors)
               .setIntroductionInfo(introducerFilename, "eval", lineno, maybeScript, pcOffset)
               .maybeMakeStrictMode(IsStrictEvalPC(pc));

        AutoStableStringChars linearChars(cx);
        if (!linearChars.initTwoByte(cx, linearStr))
            return false;

        const char16_t* chars = linearChars.twoByteRange().start().get();
        SourceBufferHolder::Ownership ownership = linearChars.maybeGiveOwnershipToCaller()
                                                  ? SourceBufferHolder::GiveOwnership
                                                  : SourceBufferHolder::NoOwnership;
        SourceBufferHolder srcBuf(chars, linearStr->length(), ownership);
        JSScript* compiled = frontend::CompileScript(cx, &cx->tempLifoAlloc(),
                                                     scopeobj, staticScope, callerScript,
                                                     options, srcBuf, linearStr, staticLevel);
        if (!compiled)
            return false;

        if (compiled->strict())
            staticScope->setStrict();

        esg.setNewScript(compiled);
    }

    // Primitive 'this' values should have been filtered out by Ion. If boxed,
    // the calling frame cannot be updated to store the new object.
    MOZ_ASSERT(thisValue.isObject() || thisValue.isUndefined() || thisValue.isNull());

    // When eval'ing strict code in a non-strict context, compute the 'this'
    // value to use from what the caller passed in. This isn't necessary if
    // the callee is not strict, as it will compute the non-strict 'this'
    // value as necessary while it executes.
    RootedValue nthisValue(cx, thisValue);
    if (!callerScript->strict() && esg.script()->strict() && !thisValue.isObject()) {
        JSObject* obj = BoxNonStrictThis(cx, thisValue);
        if (!obj)
            return false;
        nthisValue = ObjectValue(*obj);
    }

    return ExecuteKernel(cx, esg.script(), *scopeobj, nthisValue, newTargetValue,
                         ExecuteType(DIRECT_EVAL), NullFramePtr() /* evalInFrame */, vp.address());
}

/* ES6 final draft 21.2.5.2.2. */
RegExpRunStatus
js::ExecuteRegExp(JSContext* cx, HandleObject regexp, HandleString string,
                  MatchPairs* matches, RegExpStaticsUpdate staticsUpdate)
{
    /*
     * WARNING: Despite the presence of spec step comment numbers, this
     *          algorithm isn't consistent with any ES6 version, draft or
     *          otherwise.  YOU HAVE BEEN WARNED.
     */

    /* Steps 1-2 performed by the caller. */
    Rooted<RegExpObject*> reobj(cx, &regexp->as<RegExpObject>());

    RegExpGuard re(cx);
    if (!reobj->getShared(cx, &re))
        return RegExpRunStatus_Error;

    RegExpStatics* res;
    if (staticsUpdate == UpdateRegExpStatics) {
        res = cx->global()->getRegExpStatics(cx);
        if (!res)
            return RegExpRunStatus_Error;
    } else {
        res = nullptr;
    }

    RootedLinearString input(cx, string->ensureLinear(cx));
    if (!input)
        return RegExpRunStatus_Error;

    /* Step 3. */
    size_t length = input->length();

    /* Steps 4-5. */
    RootedValue lastIndex(cx, reobj->getLastIndex());
    int searchIndex;
    if (lastIndex.isInt32()) {
        /* Aggressively avoid doubles. */
        searchIndex = lastIndex.toInt32();
    } else {
        double d;
        if (!ToInteger(cx, lastIndex, &d))
            return RegExpRunStatus_Error;

        /* Inlined steps 6-10, 15.a with doubles to detect failure case. */
        if (reobj->needUpdateLastIndex() && (d < 0 || d > length)) {
            /* Steps 15.a.i-ii. */
            if (!SetLastIndex(cx, reobj, 0))
                return RegExpRunStatus_Error;

            /* Step 15.a.iii. */
            return RegExpRunStatus_Success_NotFound;
        }

        searchIndex = int(d);
    }

    /*
     * Steps 6-10.
     *
     * Also make sure that we have a MatchPairs for regexps which update their
     * last index, as we won't compute the last index otherwise.
     */
    Maybe<ScopedMatchPairs> alternateMatches;
    if (!reobj->needUpdateLastIndex()) {
        searchIndex = 0;
    } else if (!matches) {
        alternateMatches.emplace(&cx->tempLifoAlloc());
        matches = &alternateMatches.ref();
    }

    /* Step 15.a. */
    if (searchIndex < 0 || size_t(searchIndex) > length) {
        /* Steps 15.a.i-ii. */
        if (!SetLastIndex(cx, reobj, 0))
            return RegExpRunStatus_Error;

        /* Step 15.a.iii. */
        return RegExpRunStatus_Success_NotFound;
    }

    /* Steps 12-13. */
    if (reobj->unicode()) {
        /*
         * ES6 21.2.2.2 step 2.
         *   Let listIndex be the index into Input of the character that was
         *   obtained from element index of str.
         *
         * In the spec, pattern match is performed with decoded Unicode code
         * points, but our implementation performs it with UTF-16 encoded
         * string.  In step 2, we should decrement searchIndex (index) if it
         * points the trail surrogate that has corresponding lead surrogate.
         *
         *   var r = /\uD83D\uDC38/ug;
         *   r.lastIndex = 1;
         *   var str = "\uD83D\uDC38";
         *   var result = r.exec(str); // pattern match starts from index 0
         *   print(result.index);      // prints 0
         *
//.........这里部分代码省略.........

bool
js::DirectEvalStringFromIon(JSContext *cx,
                            HandleObject scopeobj, HandleScript callerScript,
                            HandleValue thisValue, HandleString str,
                            jsbytecode *pc, MutableHandleValue vp)
{
    AssertInnerizedScopeChain(cx, *scopeobj);

    Rooted<GlobalObject*> scopeObjGlobal(cx, &scopeobj->global());
    if (!GlobalObject::isRuntimeCodeGenEnabled(cx, scopeObjGlobal)) {
        JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_CSP_BLOCKED_EVAL);
        return false;
    }

    // ES5 15.1.2.1 steps 2-8.

    unsigned staticLevel = callerScript->staticLevel() + 1;

    Rooted<JSFlatString*> flatStr(cx, str->ensureFlat(cx));
    if (!flatStr)
        return false;

    size_t length = flatStr->length();
    ConstTwoByteChars chars(flatStr->chars(), length);

    EvalJSONResult ejr = TryEvalJSON(cx, callerScript, chars, length, vp);
    if (ejr != EvalJSON_NotJSON)
        return ejr == EvalJSON_Success;

    EvalScriptGuard esg(cx);

    // Ion will not perform cross compartment direct eval calls.
    JSPrincipals *principals = cx->compartment()->principals;

    esg.lookupInEvalCache(flatStr, callerScript, pc);

    if (!esg.foundScript()) {
        JSScript *script;
        const char *filename;
        unsigned lineno;
        JSPrincipals *originPrincipals;
        uint32_t pcOffset;
        CurrentScriptFileLineOrigin(cx, &script, &filename, &lineno, &pcOffset,
                                    &originPrincipals, CALLED_FROM_JSOP_EVAL);

        const char *introducerFilename = filename;
        if (script && script->scriptSource()->introducerFilename())
            introducerFilename = script->scriptSource()->introducerFilename();

        CompileOptions options(cx);
        options.setFileAndLine(filename, 1)
               .setCompileAndGo(true)
               .setForEval(true)
               .setNoScriptRval(false)
               .setPrincipals(principals)
               .setOriginPrincipals(originPrincipals)
               .setIntroductionInfo(introducerFilename, "eval", lineno, script, pcOffset);
        JSScript *compiled = frontend::CompileScript(cx, &cx->tempLifoAlloc(),
                                                     scopeobj, callerScript, options,
                                                     chars.get(), length, flatStr, staticLevel);
        if (!compiled)
            return false;

        MarkFunctionsWithinEvalScript(compiled);

        esg.setNewScript(compiled);
    }

    // Primitive 'this' values should have been filtered out by Ion. If boxed,
    // the calling frame cannot be updated to store the new object.
    JS_ASSERT(thisValue.isObject() || thisValue.isUndefined() || thisValue.isNull());

    return ExecuteKernel(cx, esg.script(), *scopeobj, thisValue, ExecuteType(DIRECT_EVAL),
                         NullFramePtr() /* evalInFrame */, vp.address());
}