Fix generation of arguments object used in nested arrow functions and…

… eval codes

Signed-off-by: HyukWoo Park <[email protected]>

src/interpreter/ByteCodeInterpreter.cpp

@@ -4964,10 +4964,24 @@ NEVER_INLINE void InterpreterSlowPath::setObjectOpcodeSlowCase(ExecutionState& s
 
 NEVER_INLINE void InterpreterSlowPath::ensureArgumentsObjectOperation(ExecutionState& state, ByteCodeBlock* byteCodeBlock, Value* registerFile)
 {
-    auto functionRecord = state.mostNearestFunctionLexicalEnvironment()->record()->asDeclarativeEnvironmentRecord()->asFunctionEnvironmentRecord();
-    auto functionObject = functionRecord->functionObject()->asScriptFunctionObject();
-    bool isMapped = functionObject->interpretedCodeBlock()->shouldHaveMappedArguments();
-    functionObject->generateArgumentsObject(state, state.argc(), state.argv(), functionRecord, registerFile + byteCodeBlock->m_requiredOperandRegisterNumber, isMapped);
+    FunctionEnvironmentRecord* funcRecord = nullptr;
+    ScriptFunctionObject* funcObject = nullptr;
+
+    // find the most nearest lexical function which is not an arrow function
+    ExecutionState* es = &state;
+    while (es) {
+        EnvironmentRecord* record = es->lexicalEnvironment()->record();
+        if (record->isDeclarativeEnvironmentRecord() && record->asDeclarativeEnvironmentRecord()->isFunctionEnvironmentRecord() && !record->asDeclarativeEnvironmentRecord()->asFunctionEnvironmentRecord()->functionObject()->isScriptArrowFunctionObject()) {
+            funcRecord = record->asDeclarativeEnvironmentRecord()->asFunctionEnvironmentRecord();
+            funcObject = funcRecord->functionObject()->asScriptFunctionObject();
+            break;
+        }
+        es = es->parent();
+    }
+
+    ASSERT(!!funcRecord && !!funcObject && !funcObject->isScriptArrowFunctionObject());
+    bool isMapped = funcObject->interpretedCodeBlock()->shouldHaveMappedArguments();
+    funcObject->generateArgumentsObject(state, es->argc(), es->argv(), funcRecord, registerFile + byteCodeBlock->m_requiredOperandRegisterNumber, isMapped);
 }
 
 NEVER_INLINE int InterpreterSlowPath::evaluateImportAssertionOperation(ExecutionState& state, const Value& options)

src/parser/CodeBlock.cpp

@@ -409,20 +409,23 @@ void InterpretedCodeBlock::recordFunctionParsingInfo(ASTScopeContext* scopeCtx,
     initBlockScopeInformation(scopeCtx);
 }
 
-void InterpretedCodeBlock::captureArguments()
+void InterpretedCodeBlock::captureArguments(bool needToAllocateOnStack)
 {
     AtomicString arguments = m_context->staticStrings().arguments;
     ASSERT(!hasParameterName(arguments));
-    ASSERT(!isGlobalCodeBlock() && !isArrowFunctionExpression());
+    ASSERT(!isGlobalCodeBlock() && !isArrowFunctionExpression() && isKindOfFunction());
 
     if (m_usesArgumentsObject) {
+        size_t idx = findVarName(arguments);
+        ASSERT(idx != SIZE_MAX);
+        m_identifierInfos[idx].m_needToAllocateOnStack &= needToAllocateOnStack;
         return;
     }
 
     m_usesArgumentsObject = true;
     if (findVarName(arguments) == SIZE_MAX) {
         IdentifierInfo info;
-        info.m_needToAllocateOnStack = true;
+        info.m_needToAllocateOnStack = needToAllocateOnStack;
         info.m_isMutable = true;
         info.m_isParameterName = false;
         info.m_isExplicitlyDeclaredOrParameterName = false;
@@ -466,7 +469,7 @@ std::pair<bool, size_t> InterpretedCodeBlock::tryCaptureIdentifiersFromChildCode
     if (UNLIKELY(blockIndex < m_functionBodyBlockIndex)) {
         // case for functions located in parameters
         if (!isParameterName(name) && name != m_context->staticStrings().arguments) {
-            // it's possible to access parameter or arguemnts object of upper function
+            // it's possible to access parameter or arguments object of upper function
             return std::make_pair(false, SIZE_MAX);
         }
     }

src/parser/CodeBlock.h

@@ -847,7 +847,7 @@ class InterpretedCodeBlock : public CodeBlock {
     // You can use this function on ScriptParser only
     void computeVariables();
     // You can use this function on ScriptParser only
-    void captureArguments();
+    void captureArguments(bool needToAllocateOnStack);
 
     // You can use this function on ScriptParser only
     /* capture ok, block vector index(if not block variable, returns SIZE_MAX) */

src/parser/Script.cpp

@@ -602,24 +602,27 @@ Value Script::executeLocal(ExecutionState& state, Value thisValue, InterpretedCo
     if (isEvalCodeOnFunction && m_topCodeBlock->usesArgumentsObject()) {
         AtomicString arguments = state.context()->staticStrings().arguments;
 
-        FunctionEnvironmentRecord* fnRecord = nullptr;
-        {
-            LexicalEnvironment* env = state.lexicalEnvironment();
-            while (env) {
-                if (env->record()->isDeclarativeEnvironmentRecord() && env->record()->asDeclarativeEnvironmentRecord()->isFunctionEnvironmentRecord()) {
-                    fnRecord = env->record()->asDeclarativeEnvironmentRecord()->asFunctionEnvironmentRecord();
-                    break;
-                }
-                env = env->outerEnvironment();
+        FunctionEnvironmentRecord* funcRecord = nullptr;
+        ScriptFunctionObject* funcObject = nullptr;
+
+        // find the most nearest lexical function which is not an arrow function
+        ExecutionState* es = &state;
+        while (es) {
+            EnvironmentRecord* record = es->lexicalEnvironment()->record();
+            if (record->isDeclarativeEnvironmentRecord() && record->asDeclarativeEnvironmentRecord()->isFunctionEnvironmentRecord() && !record->asDeclarativeEnvironmentRecord()->asFunctionEnvironmentRecord()->functionObject()->isScriptArrowFunctionObject()) {
+                funcRecord = record->asDeclarativeEnvironmentRecord()->asFunctionEnvironmentRecord();
+                funcObject = funcRecord->functionObject()->asScriptFunctionObject();
+                break;
             }
+            es = es->parent();
         }
-        ASSERT(!!fnRecord);
+        ASSERT(!!funcRecord && !!funcObject && !funcObject->isScriptArrowFunctionObject());
 
-        FunctionObject* callee = state.resolveCallee();
-        if (fnRecord->hasBinding(newState, arguments).m_index == SIZE_MAX && callee->isScriptFunctionObject()) {
+        if (funcRecord->hasBinding(newState, arguments).m_index == SIZE_MAX) {
+            // If eval code uses the arguments object but not yet created in outer function, generate it
             // FIXME check if formal parameters does not contain a rest parameter, any binding patterns, or any initializers.
-            bool isMapped = !callee->codeBlock()->asInterpretedCodeBlock()->hasParameterOtherThanIdentifier() && !inStrict;
-            callee->asScriptFunctionObject()->generateArgumentsObject(newState, state.argc(), state.argv(), fnRecord, nullptr, isMapped);
+            bool isMapped = !funcObject->interpretedCodeBlock()->hasParameterOtherThanIdentifier() && !inStrict;
+            funcObject->generateArgumentsObject(newState, es->argc(), es->argv(), funcRecord, nullptr, isMapped);
         }
     }
 

src/parser/ScriptParser.cpp

@@ -174,7 +174,6 @@ InterpretedCodeBlock* ScriptParser::generateCodeBlockTreeFromASTWalker(Context*
         }
 
         AtomicString arguments = ctx->staticStrings().arguments;
-
         for (size_t i = 0; i < scopeCtx->m_childBlockScopes.size(); i++) {
             ASTBlockContext* childBlockContext = scopeCtx->m_childBlockScopes[i];
 
@@ -201,7 +200,8 @@ InterpretedCodeBlock* ScriptParser::generateCodeBlockTreeFromASTWalker(Context*
 
                     if (needToCaptureArguments) {
                         ASSERT(argumentsObjectHolder->isKindOfFunction() && !argumentsObjectHolder->isArrowFunctionExpression());
-                        argumentsObjectHolder->captureArguments();
+                        // if argumentsObjectHolder and codeBlock are not same, arguments should be allocated on the heap
+                        argumentsObjectHolder->captureArguments(argumentsObjectHolder == codeBlock);
 
                         if (UNLIKELY(!codeBlock->isKindOfFunction() || codeBlock->isArrowFunctionExpression())) {
                             InterpretedCodeBlock* p = codeBlock;
@@ -213,6 +213,9 @@ InterpretedCodeBlock* ScriptParser::generateCodeBlockTreeFromASTWalker(Context*
                             ASSERT(p == argumentsObjectHolder);
                             codeBlock->markHeapAllocatedEnvironmentFromHere(blockIndex, argumentsObjectHolder);
                         }
+
+                        // arguments captured, so continue to the next
+                        continue;
                     }
                 }
 

src/runtime/ScriptFunctionObject.cpp

@@ -163,6 +163,9 @@ Value ScriptFunctionObject::construct(ExecutionState& state, const size_t argc,
 
 void ScriptFunctionObject::generateArgumentsObject(ExecutionState& state, size_t argc, Value* argv, FunctionEnvironmentRecord* environmentRecordWillArgumentsObjectBeLocatedIn, Value* stackStorage, bool isMapped)
 {
+    // arrow function should not create an ArgumentsObject
+    ASSERT(!isScriptArrowFunctionObject());
+
     if (environmentRecordWillArgumentsObjectBeLocatedIn->m_argumentsObject->isArgumentsObject()) {
         return;
     }