X-Git-Url: https://git.saurik.com/apple/javascriptcore.git/blobdiff_plain/1df5f87f1309a8daa30dabdee855f48ae40d14ab..6fe7ccc865dc7d7541b93c5bcaf6368d2c98a174:/runtime/CommonSlowPaths.h?ds=inline

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+/*
+ * Copyright (C) 2011, 2012 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#ifndef CommonSlowPaths_h
+#define CommonSlowPaths_h
+
+#include "CodeBlock.h"
+#include "CodeSpecializationKind.h"
+#include "ExceptionHelpers.h"
+#include "JSArray.h"
+
+namespace JSC {
+
+// The purpose of this namespace is to include slow paths that are shared
+// between the interpreter and baseline JIT. They are written to be agnostic
+// with respect to the slow-path calling convention, but they do rely on the
+// JS code being executed more-or-less directly from bytecode (so the call
+// frame layout is unmodified, making it potentially awkward to use these
+// from any optimizing JIT, like the DFG).
+
+namespace CommonSlowPaths {
+
+ALWAYS_INLINE ExecState* arityCheckFor(ExecState* exec, RegisterFile* registerFile, CodeSpecializationKind kind)
+{
+    JSFunction* callee = jsCast<JSFunction*>(exec->callee());
+    ASSERT(!callee->isHostFunction());
+    CodeBlock* newCodeBlock = &callee->jsExecutable()->generatedBytecodeFor(kind);
+    int argumentCountIncludingThis = exec->argumentCountIncludingThis();
+
+    // This ensures enough space for the worst case scenario of zero arguments passed by the caller.
+    if (!registerFile->grow(exec->registers() + newCodeBlock->numParameters() + newCodeBlock->m_numCalleeRegisters))
+        return 0;
+
+    ASSERT(argumentCountIncludingThis < newCodeBlock->numParameters());
+
+    // Too few arguments -- copy call frame and arguments, then fill in missing arguments with undefined.
+    size_t delta = newCodeBlock->numParameters() - argumentCountIncludingThis;
+    Register* src = exec->registers();
+    Register* dst = exec->registers() + delta;
+
+    int i;
+    int end = -ExecState::offsetFor(argumentCountIncludingThis);
+    for (i = -1; i >= end; --i)
+        dst[i] = src[i];
+
+    end -= delta;
+    for ( ; i >= end; --i)
+        dst[i] = jsUndefined();
+
+    ExecState* newExec = ExecState::create(dst);
+    ASSERT((void*)newExec <= registerFile->end());
+    return newExec;
+}
+
+ALWAYS_INLINE bool opInstanceOfSlow(ExecState* exec, JSValue value, JSValue baseVal, JSValue proto)
+{
+    ASSERT(!value.isCell() || !baseVal.isCell() || !proto.isCell()
+           || !value.isObject() || !baseVal.isObject() || !proto.isObject() 
+           || !asObject(baseVal)->structure()->typeInfo().implementsDefaultHasInstance());
+
+
+    // ECMA-262 15.3.5.3:
+    // Throw an exception either if baseVal is not an object, or if it does not implement 'HasInstance' (i.e. is a function).
+    TypeInfo typeInfo(UnspecifiedType);
+    if (!baseVal.isObject() || !(typeInfo = asObject(baseVal)->structure()->typeInfo()).implementsHasInstance()) {
+        exec->globalData().exception = createInvalidParamError(exec, "instanceof", baseVal);
+        return false;
+    }
+    ASSERT(typeInfo.type() != UnspecifiedType);
+
+    if (!typeInfo.overridesHasInstance() && !value.isObject())
+        return false;
+
+    return asObject(baseVal)->methodTable()->hasInstance(asObject(baseVal), exec, value, proto);
+}
+
+inline bool opIn(ExecState* exec, JSValue propName, JSValue baseVal)
+{
+    if (!baseVal.isObject()) {
+        exec->globalData().exception = createInvalidParamError(exec, "in", baseVal);
+        return false;
+    }
+
+    JSObject* baseObj = asObject(baseVal);
+
+    uint32_t i;
+    if (propName.getUInt32(i))
+        return baseObj->hasProperty(exec, i);
+
+    Identifier property(exec, propName.toString(exec)->value(exec));
+    if (exec->globalData().exception)
+        return false;
+    return baseObj->hasProperty(exec, property);
+}
+
+ALWAYS_INLINE JSValue opResolve(ExecState* exec, Identifier& ident)
+{
+    ScopeChainNode* scopeChain = exec->scopeChain();
+
+    ScopeChainIterator iter = scopeChain->begin();
+    ScopeChainIterator end = scopeChain->end();
+    ASSERT(iter != end);
+    
+    do {
+        JSObject* o = iter->get();
+        PropertySlot slot(o);
+        if (o->getPropertySlot(exec, ident, slot))
+            return slot.getValue(exec, ident);
+    } while (++iter != end);
+
+    exec->globalData().exception = createUndefinedVariableError(exec, ident);
+    return JSValue();
+}
+
+ALWAYS_INLINE JSValue opResolveSkip(ExecState* exec, Identifier& ident, int skip)
+{
+    ScopeChainNode* scopeChain = exec->scopeChain();
+
+    ScopeChainIterator iter = scopeChain->begin();
+    ScopeChainIterator end = scopeChain->end();
+    ASSERT(iter != end);
+    CodeBlock* codeBlock = exec->codeBlock();
+    bool checkTopLevel = codeBlock->codeType() == FunctionCode && codeBlock->needsFullScopeChain();
+    ASSERT(skip || !checkTopLevel);
+    if (checkTopLevel && skip--) {
+        if (exec->uncheckedR(codeBlock->activationRegister()).jsValue())
+            ++iter;
+    }
+    while (skip--) {
+        ++iter;
+        ASSERT(iter != end);
+    }
+    do {
+        JSObject* o = iter->get();
+        PropertySlot slot(o);
+        if (o->getPropertySlot(exec, ident, slot))
+            return slot.getValue(exec, ident);
+    } while (++iter != end);
+
+    exec->globalData().exception = createUndefinedVariableError(exec, ident);
+    return JSValue();
+}
+
+ALWAYS_INLINE JSValue opResolveWithBase(ExecState* exec, Identifier& ident, Register& baseSlot)
+{
+    ScopeChainNode* scopeChain = exec->scopeChain();
+
+    ScopeChainIterator iter = scopeChain->begin();
+    ScopeChainIterator end = scopeChain->end();
+
+    // FIXME: add scopeDepthIsZero optimization
+
+    ASSERT(iter != end);
+
+    JSObject* base;
+    do {
+        base = iter->get();
+        PropertySlot slot(base);
+        if (base->getPropertySlot(exec, ident, slot)) {
+            JSValue result = slot.getValue(exec, ident);
+            if (exec->globalData().exception)
+                return JSValue();
+
+            baseSlot = JSValue(base);
+            return result;
+        }
+        ++iter;
+    } while (iter != end);
+
+    exec->globalData().exception = createUndefinedVariableError(exec, ident);
+    return JSValue();
+}
+
+ALWAYS_INLINE JSValue opResolveWithThis(ExecState* exec, Identifier& ident, Register& baseSlot)
+{
+    ScopeChainNode* scopeChain = exec->scopeChain();
+
+    ScopeChainIterator iter = scopeChain->begin();
+    ScopeChainIterator end = scopeChain->end();
+
+    // FIXME: add scopeDepthIsZero optimization
+
+    ASSERT(iter != end);
+
+    JSObject* base;
+    do {
+        base = iter->get();
+        ++iter;
+        PropertySlot slot(base);
+        if (base->getPropertySlot(exec, ident, slot)) {
+            JSValue result = slot.getValue(exec, ident);
+            if (exec->globalData().exception)
+                return JSValue();
+
+            // All entries on the scope chain should be EnvironmentRecords (activations etc),
+            // other then 'with' object, which are directly referenced from the scope chain,
+            // and the global object. If we hit either an EnvironmentRecord or a global
+            // object at the end of the scope chain, this is undefined. If we hit a non-
+            // EnvironmentRecord within the scope chain, pass the base as the this value.
+            if (iter == end || base->structure()->typeInfo().isEnvironmentRecord())
+                baseSlot = jsUndefined();
+            else
+                baseSlot = JSValue(base);
+            return result;
+        }
+    } while (iter != end);
+
+    exec->globalData().exception = createUndefinedVariableError(exec, ident);
+    return JSValue();
+}
+
+} } // namespace JSC::CommonSlowPaths
+
+#endif // CommonSlowPaths_h
+