Examples with ArgumentsObject com.github.anba.es6draft.runtime.types.builtins.ArgumentsObject used on opensource projects

Example 1 with ArgumentsObject

use of com.github.anba.es6draft.runtime.types.builtins.ArgumentsObject in project es6draft by anba.

the class FunctionDeclarationInstantiationGenerator method generate.

private void generate(FunctionNode function, CodeVisitor mv) {
    Variable<ExecutionContext> context = mv.getParameter(EXECUTION_CONTEXT, ExecutionContext.class);
    Variable<LexicalEnvironment<FunctionEnvironmentRecord>> env = mv.newVariable("env", LexicalEnvironment.class).uncheckedCast();
    Variable<FunctionEnvironmentRecord> envRec = mv.newVariable("envRec", FunctionEnvironmentRecord.class);
    Variable<FunctionObject> fo = null;
    Variable<Undefined> undefined = mv.newVariable("undef", Undefined.class);
    mv.loadUndefined();
    mv.store(undefined);
    FunctionScope fscope = function.getScope();
    boolean hasParameters = !function.getParameters().getFormals().isEmpty();
    Variable<Iterator<?>> iterator = null;
    if (hasParameters) {
        iterator = mv.newVariable("iterator", Iterator.class).uncheckedCast();
        mv.loadParameter(ARGUMENTS, Object[].class);
        mv.invoke(Methods.Arrays_asList);
        mv.invoke(Methods.List_iterator);
        mv.store(iterator);
    }
    /* step 1 (omitted) */
    /* step 2 */
    getLexicalEnvironment(context, env, mv);
    /* step 3 */
    getEnvironmentRecord(env, envRec, mv);
    /* step 4 */
    // RuntimeInfo.Function code = func.getCode();
    /* step 5 */
    boolean strict = IsStrict(function);
    /* step 6 */
    FormalParameterList formals = function.getParameters();
    /* step 7 */
    List<Name> parameterNames = BoundNames(formals);
    HashSet<Name> parameterNamesSet = new HashSet<>(parameterNames);
    /* step 8 */
    boolean hasDuplicates = parameterNames.size() != parameterNamesSet.size();
    /* step 9 */
    boolean simpleParameterList = IsSimpleParameterList(formals);
    /* step 10 */
    boolean hasParameterExpressions = ContainsExpression(formals);
    // invariant: hasDuplicates => simpleParameterList
    assert !hasDuplicates || simpleParameterList;
    // invariant: hasParameterExpressions => !simpleParameterList
    assert !hasParameterExpressions || !simpleParameterList;
    /* step 11 */
    Set<Name> varNames = VarDeclaredNames(function);
    /* step 12 */
    List<StatementListItem> varDeclarations = VarScopedDeclarations(function);
    /* step 13 */
    Set<Name> lexicalNames = LexicallyDeclaredNames(function);
    /* step 14 */
    HashSet<Name> functionNames = new HashSet<>();
    /* step 15 */
    ArrayDeque<HoistableDeclaration> functionsToInitialize = new ArrayDeque<>();
    /* step 16 */
    for (StatementListItem item : reverse(varDeclarations)) {
        if (item instanceof HoistableDeclaration) {
            HoistableDeclaration d = (HoistableDeclaration) item;
            Name fn = BoundName(d);
            if (functionNames.add(fn)) {
                functionsToInitialize.addFirst(d);
            }
        }
    }
    if (!functionsToInitialize.isEmpty()) {
        fo = mv.newVariable("fo", FunctionObject.class);
    }
    /* step 17 */
    // Optimization: Skip 'arguments' allocation if it's not referenced within the function.
    boolean argumentsObjectNeeded = function.getScope().needsArguments();
    Name arguments = function.getScope().arguments();
    argumentsObjectNeeded &= arguments != null;
    /* step 18 */
    if (function.getThisMode() == FunctionNode.ThisMode.Lexical) {
        argumentsObjectNeeded = false;
    } else /* step 19 */
    if (parameterNamesSet.contains(arguments)) {
        argumentsObjectNeeded = false;
    } else /* step 20 */
    if (!hasParameterExpressions) {
        if (functionNames.contains(arguments) || lexicalNames.contains(arguments)) {
            argumentsObjectNeeded = false;
        }
    }
    /* step 21 */
    for (Name paramName : function.getScope().parameterNames()) {
        BindingOp<FunctionEnvironmentRecord> op = BindingOp.of(envRec, paramName);
        op.createMutableBinding(envRec, paramName, false, mv);
        if (hasDuplicates) {
            op.initializeBinding(envRec, paramName, undefined, mv);
        }
    }
    /* step 22 */
    if (argumentsObjectNeeded) {
        assert arguments != null;
        Variable<ArgumentsObject> argumentsObj = mv.newVariable("argumentsObj", ArgumentsObject.class);
        if (strict || !simpleParameterList) {
            CreateUnmappedArgumentsObject(mv);
        } else if (formals.getFormals().isEmpty()) {
            CreateMappedArgumentsObject(mv);
        } else {
            CreateMappedArgumentsObject(env, formals, mv);
        }
        mv.store(argumentsObj);
        BindingOp<FunctionEnvironmentRecord> op = BindingOp.of(envRec, arguments);
        if (strict) {
            op.createImmutableBinding(envRec, arguments, false, mv);
        } else {
            op.createMutableBinding(envRec, arguments, false, mv);
        }
        op.initializeBinding(envRec, arguments, argumentsObj, mv);
        parameterNames.add(arguments);
        parameterNamesSet.add(arguments);
    }
    /* steps 24-26 */
    if (hasParameters) {
        if (hasDuplicates) {
            /* step 24 */
            BindingInitialization(codegen, function, env, iterator, mv);
        } else {
            /* step 25 */
            BindingInitialization(codegen, function, env, envRec, iterator, mv);
        }
    }
    /* steps 27-28 */
    HashSet<Name> instantiatedVarNames;
    Variable<? extends LexicalEnvironment<?>> varEnv;
    Variable<? extends DeclarativeEnvironmentRecord> varEnvRec;
    if (!hasParameterExpressions) {
        assert fscope == fscope.variableScope();
        /* step 27.a (note) */
        /* step 27.b */
        instantiatedVarNames = new HashSet<>(parameterNames);
        /* step 27.c */
        for (Name varName : varNames) {
            if (instantiatedVarNames.add(varName)) {
                BindingOp<FunctionEnvironmentRecord> op = BindingOp.of(envRec, varName);
                op.createMutableBinding(envRec, varName, false, mv);
                op.initializeBinding(envRec, varName, undefined, mv);
            }
        }
        /* steps 27.d-27.e */
        varEnv = env;
        varEnvRec = envRec;
    } else {
        assert fscope != fscope.variableScope();
        mv.enterScope(fscope.variableScope());
        /* step 28.a (note) */
        /* step 28.b */
        varEnv = mv.newVariable("varEnv", LexicalEnvironment.class).uncheckedCast();
        newDeclarativeEnvironment(env, mv);
        mv.store(varEnv);
        /* step 28.c */
        varEnvRec = mv.newVariable("varEnvRec", DeclarativeEnvironmentRecord.class);
        getEnvironmentRecord(varEnv, varEnvRec, mv);
        /* step 28.d */
        setVariableEnvironment(varEnv, mv);
        /* step 28.e */
        instantiatedVarNames = new HashSet<>();
        /* step 28.f */
        Variable<Object> tempValue = null;
        for (Name varName : varNames) {
            if (instantiatedVarNames.add(varName)) {
                BindingOp<DeclarativeEnvironmentRecord> op = BindingOp.of(varEnvRec, varName);
                op.createMutableBinding(varEnvRec, varName, false, mv);
                if (!parameterNamesSet.contains(varName) || functionNames.contains(varName)) {
                    op.initializeBinding(varEnvRec, varName, undefined, mv);
                } else {
                    BindingOp.of(envRec, varName).getBindingValue(envRec, varName, strict, mv);
                    if (tempValue == null) {
                        tempValue = mv.newVariable("tempValue", Object.class);
                    }
                    mv.store(tempValue);
                    op.initializeBinding(varEnvRec, varName, tempValue, mv);
                }
            }
        }
    }
    /* step 29 (B.3.3 Block-Level Function Declarations Web Legacy Compatibility Semantics) */
    for (Name fname : function.getScope().blockFunctionNames()) {
        if (instantiatedVarNames.add(fname)) {
            BindingOp<DeclarativeEnvironmentRecord> op = BindingOp.of(varEnvRec, fname);
            op.createMutableBinding(varEnvRec, fname, false, mv);
            op.initializeBinding(varEnvRec, fname, undefined, mv);
        }
    }
    /* steps 30-32 */
    Variable<? extends LexicalEnvironment<?>> lexEnv;
    Variable<? extends DeclarativeEnvironmentRecord> lexEnvRec;
    assert strict || fscope.variableScope() != fscope.lexicalScope();
    if (!strict || fscope.variableScope() != fscope.lexicalScope()) {
        // NB: Scopes are unmodifiable once constructed, that means we need to emit the extra
        // scope for functions with deferred strict-ness, even if this scope is not present in
        // the specification.
        mv.enterScope(fscope.lexicalScope());
        if (!lexicalNames.isEmpty()) {
            /* step 30 */
            lexEnv = mv.newVariable("lexEnv", LexicalEnvironment.class).uncheckedCast();
            newDeclarativeEnvironment(varEnv, mv);
            mv.store(lexEnv);
            /* step 32 */
            lexEnvRec = mv.newVariable("lexEnvRec", DeclarativeEnvironmentRecord.class);
            getEnvironmentRecord(lexEnv, lexEnvRec, mv);
        } else {
            // Optimization: Skip environment allocation if no lexical names are defined.
            /* step 30 */
            lexEnv = varEnv;
            /* step 32 */
            lexEnvRec = varEnvRec;
        }
    } else {
        /* step 30 */
        lexEnv = varEnv;
        /* step 32 */
        lexEnvRec = varEnvRec;
    }
    /* step 33 */
    if (lexEnv != env) {
        setLexicalEnvironment(lexEnv, mv);
    }
    /* step 34 */
    List<Declaration> lexDeclarations = LexicallyScopedDeclarations(function);
    /* step 35 */
    for (Declaration d : lexDeclarations) {
        assert !(d instanceof HoistableDeclaration);
        for (Name dn : BoundNames(d)) {
            BindingOp<DeclarativeEnvironmentRecord> op = BindingOp.of(lexEnvRec, dn);
            if (d.isConstDeclaration()) {
                op.createImmutableBinding(lexEnvRec, dn, true, mv);
            } else {
                op.createMutableBinding(lexEnvRec, dn, false, mv);
            }
        }
    }
    /* step 36 */
    for (HoistableDeclaration f : functionsToInitialize) {
        Name fn = BoundName(f);
        // stack: [] -> [fo]
        InstantiateFunctionObject(context, lexEnv, f, mv);
        mv.store(fo);
        // stack: [fo] -> []
        // Resolve the actual binding name: function(a){ function a(){} }
        // TODO: Can be removed when StaticIdResolution handles this case.
        Name name = fscope.variableScope().resolveName(fn, false);
        BindingOp<DeclarativeEnvironmentRecord> op = BindingOp.of(varEnvRec, name);
        op.setMutableBinding(varEnvRec, name, fo, false, mv);
    }
    /* step 37 */
    mv._return();
}