CodeCompiler.java

// Copyright (c) Corporation for National Research Initiatives
package org.python.compiler;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.ListIterator;
import java.util.Map;
import java.util.Stack;
import java.util.Vector;

import org.python.antlr.ParseException;
import org.python.antlr.PythonTree;
import org.python.antlr.Visitor;
import org.python.antlr.ast.Assert;
import org.python.antlr.ast.Assign;
import org.python.antlr.ast.Attribute;
import org.python.antlr.ast.AugAssign;
import org.python.antlr.ast.BinOp;
import org.python.antlr.ast.BoolOp;
import org.python.antlr.ast.Break;
import org.python.antlr.ast.Call;
import org.python.antlr.ast.ClassDef;
import org.python.antlr.ast.Compare;
import org.python.antlr.ast.Continue;
import org.python.antlr.ast.Delete;
import org.python.antlr.ast.Dict;
import org.python.antlr.ast.DictComp;
import org.python.antlr.ast.Ellipsis;
import org.python.antlr.ast.ExceptHandler;
import org.python.antlr.ast.Exec;
import org.python.antlr.ast.Expr;
import org.python.antlr.ast.Expression;
import org.python.antlr.ast.ExtSlice;
import org.python.antlr.ast.For;
import org.python.antlr.ast.FunctionDef;
import org.python.antlr.ast.GeneratorExp;
import org.python.antlr.ast.Global;
import org.python.antlr.ast.If;
import org.python.antlr.ast.IfExp;
import org.python.antlr.ast.Import;
import org.python.antlr.ast.ImportFrom;
import org.python.antlr.ast.Index;
import org.python.antlr.ast.Interactive;
import org.python.antlr.ast.Lambda;
import org.python.antlr.ast.List;
import org.python.antlr.ast.ListComp;
import org.python.antlr.ast.Name;
import org.python.antlr.ast.Nonlocal;
import org.python.antlr.ast.Num;
import org.python.antlr.ast.Pass;
import org.python.antlr.ast.Print;
import org.python.antlr.ast.Raise;
import org.python.antlr.ast.Repr;
import org.python.antlr.ast.Return;
import org.python.antlr.ast.Set;
import org.python.antlr.ast.SetComp;
import org.python.antlr.ast.Slice;
import org.python.antlr.ast.Starred;
import org.python.antlr.ast.Str;
import org.python.antlr.ast.Subscript;
import org.python.antlr.ast.Suite;
import org.python.antlr.ast.TryExcept;
import org.python.antlr.ast.TryFinally;
import org.python.antlr.ast.Tuple;
import org.python.antlr.ast.UnaryOp;
import org.python.antlr.ast.While;
import org.python.antlr.ast.With;
import org.python.antlr.ast.Yield;
import org.python.antlr.ast.alias;
import org.python.antlr.ast.cmpopType;
import org.python.antlr.ast.comprehension;
import org.python.antlr.ast.expr_contextType;
import org.python.antlr.ast.keyword;
import org.python.antlr.ast.operatorType;
import org.python.antlr.base.expr;
import org.python.antlr.base.mod;
import org.python.antlr.base.stmt;
import org.python.core.CompilerFlags;
import org.python.core.ContextGuard;
import org.python.core.ContextManager;
import org.python.core.imp;
import org.python.core.Py;
import org.python.core.PyCode;
import org.python.core.PyComplex;
import org.python.core.PyDictionary;
import org.python.core.PyException;
import org.python.core.PyFloat;
import org.python.core.PyFrame;
import org.python.core.PyFunction;
import org.python.core.PyInteger;
import org.python.core.PyList;
import org.python.core.PyLong;
import org.python.core.PyObject;
import org.python.core.PySet;
import org.python.core.PySlice;
import org.python.core.PyString;
import org.python.core.PyTuple;
import org.python.core.PyUnicode;
import org.python.core.ThreadState;
import org.objectweb.asm.Label;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;
import org.objectweb.asm.commons.Method;
import static org.python.util.CodegenUtils.*;

public class CodeCompiler extends Visitor implements Opcodes, ClassConstants {

    private static final Object Exit = new Integer(1);
    private static final Object NoExit = null;
    private Module module;
    private Code code;
    private CompilerFlags cflags;
    private int temporary;
    private expr_contextType augmode;
    private int augtmp1;
    private int augtmp2;
    private int augtmp3;
    private int augtmp4;
    private boolean fast_locals, print_results;
    private Map<String, SymInfo> tbl;
    private ScopeInfo my_scope;
    private boolean optimizeGlobals = true;
    private String className;
    private Stack<Label> continueLabels, breakLabels;
    private Stack<ExceptionHandler> exceptionHandlers;
    private Vector<Label> yields = new Vector<Label>();

    /*
     * break/continue finally's level. This is the lowest level in the exceptionHandlers which
     * should be executed at break or continue. It is saved/updated/restored when compiling loops. A
     * similar level for returns is not needed because a new CodeCompiler is used for each PyCode,
     * in other words: each 'function'. When returning through finally's all the exceptionHandlers
     * are executed.
     */
    private int bcfLevel = 0;
    private int yield_count = 0;
    private Stack<String> stack = new Stack<String>();

    public CodeCompiler(Module module, boolean print_results) {
        this.module = module;
        this.print_results = print_results;

        continueLabels = new Stack<Label>();
        breakLabels = new Stack<Label>();
        exceptionHandlers = new Stack<ExceptionHandler>();
    }

    public void getNone() throws IOException {
        code.getstatic(p(Py.class), "None", ci(PyObject.class));
    }

    public void loadFrame() throws Exception {
        code.aload(1);
    }

    public void loadThreadState() throws Exception {
        code.aload(2);
    }

    public void setLastI(int idx) throws Exception {
        loadFrame();
        code.iconst(idx);
        code.putfield(p(PyFrame.class), "f_lasti", "I");
    }

    private void loadf_back() throws Exception {
        code.getfield(p(PyFrame.class), "f_back", ci(PyFrame.class));
    }

    public int storeTop() throws Exception {
        int tmp = code.getLocal(p(PyObject.class));
        code.astore(tmp);
        return tmp;
    }

    public void setline(int line) throws Exception {
        if (module.linenumbers) {
            code.setline(line);
            loadFrame();
            code.iconst(line);
            code.invokevirtual(p(PyFrame.class), "setline", sig(Void.TYPE, Integer.TYPE));
        }
    }

    public void setline(PythonTree node) throws Exception {
        setline(node.getLine());
    }

    public void set(PythonTree node) throws Exception {
        int tmp = storeTop();
        set(node, tmp);
        code.aconst_null();
        code.astore(tmp);
        code.freeLocal(tmp);
    }

    public void set(PythonTree node, int tmp) throws Exception {
        temporary = tmp;
        visit(node);
    }

    private void saveAugTmps(PythonTree node, int count) throws Exception {
        if (count >= 4) {
            augtmp4 = code.getLocal(ci(PyObject.class));
            code.astore(augtmp4);
        }
        if (count >= 3) {
            augtmp3 = code.getLocal(ci(PyObject.class));
            code.astore(augtmp3);
        }
        if (count >= 2) {
            augtmp2 = code.getLocal(ci(PyObject.class));
            code.astore(augtmp2);
        }
        augtmp1 = code.getLocal(ci(PyObject.class));
        code.astore(augtmp1);

        code.aload(augtmp1);
        if (count >= 2) {
            code.aload(augtmp2);
        }
        if (count >= 3) {
            code.aload(augtmp3);
        }
        if (count >= 4) {
            code.aload(augtmp4);
        }
    }

    private void restoreAugTmps(PythonTree node, int count) throws Exception {
        code.aload(augtmp1);
        code.freeLocal(augtmp1);
        if (count == 1) {
            return;
        }
        code.aload(augtmp2);
        code.freeLocal(augtmp2);
        if (count == 2) {
            return;
        }
        code.aload(augtmp3);
        code.freeLocal(augtmp3);
        if (count == 3) {
            return;
        }
        code.aload(augtmp4);
        code.freeLocal(augtmp4);
    }

    static boolean checkOptimizeGlobals(boolean fast_locals, ScopeInfo scope) {
        return fast_locals && !scope.exec && !scope.from_import_star;
    }

    void parse(mod node, Code code, boolean fast_locals, String className, Str classDoc,
            boolean classBody, ScopeInfo scope, CompilerFlags cflags) throws Exception {
        this.fast_locals = fast_locals;
        this.className = className;
        this.code = code;
        this.cflags = cflags;
        this.my_scope = scope;
        this.tbl = scope.tbl;

        // BEGIN preparse
        if (classBody) {
            // Set the class's __module__ to __name__. fails when there's no __name__
            loadFrame();
            code.ldc("__module__");

            loadFrame();
            code.ldc("__name__");
            code.invokevirtual(p(PyFrame.class), "getname", sig(PyObject.class, String.class));
            code.invokevirtual(p(PyFrame.class), "setlocal",
                    sig(Void.TYPE, String.class, PyObject.class));

            if (classDoc != null) {
                loadFrame();
                code.ldc("__doc__");
                visit(classDoc);
                code.invokevirtual(p(PyFrame.class), "setlocal",
                        sig(Void.TYPE, String.class, PyObject.class));
            }
        }

        Label genswitch = new Label();
        if (my_scope.generator) {
            code.goto_(genswitch);
        }
        Label start = new Label();
        code.label(start);

        int nparamcell = my_scope.jy_paramcells.size();
        if (nparamcell > 0) {
            java.util.List<String> paramcells = my_scope.jy_paramcells;
            for (int i = 0; i < nparamcell; i++) {
                code.aload(1);
                SymInfo syminf = tbl.get(paramcells.get(i));
                code.iconst(syminf.locals_index);
                code.iconst(syminf.env_index);
                code.invokevirtual(p(PyFrame.class), "to_cell",
                        sig(Void.TYPE, Integer.TYPE, Integer.TYPE));
            }
        }
        // END preparse

        optimizeGlobals = checkOptimizeGlobals(fast_locals, my_scope);

        if (my_scope.max_with_count > 0) {
            // allocate for all the with-exits we will have in the frame;
            // this allows yield and with to happily co-exist
            loadFrame();
            code.iconst(my_scope.max_with_count);
            code.anewarray(p(PyObject.class));
            code.putfield(p(PyFrame.class), "f_exits", ci(PyObject[].class));
        }

        Object exit = visit(node);

        if (classBody) {
            loadFrame();
            code.invokevirtual(p(PyFrame.class), "getf_locals", sig(PyObject.class));
            code.areturn();
        } else {
            if (exit == null) {
                setLastI(-1);

                getNone();
                code.areturn();
            }
        }

        // BEGIN postparse

        // similar to visitResume code in pyasm.py
        if (my_scope.generator) {
            code.label(genswitch);

            code.aload(1);
            code.getfield(p(PyFrame.class), "f_lasti", "I");
            Label[] y = new Label[yields.size() + 1];

            y[0] = start;
            for (int i = 1; i < y.length; i++) {
                y[i] = yields.get(i - 1);
            }
            code.tableswitch(0, y.length - 1, start, y);
        }
        // END postparse
    }

    @Override
    public Object visitInteractive(Interactive node) throws Exception {
        traverse(node);
        return null;
    }

    @Override
    public Object visitModule(org.python.antlr.ast.Module suite) throws Exception {
        Str docStr = getDocStr(suite.getInternalBody());
        if (docStr != null) {
            loadFrame();
            code.ldc("__doc__");
            visit(docStr);
            code.invokevirtual(p(PyFrame.class), "setglobal",
                    sig(Void.TYPE, String.class, PyObject.class));
        }
        traverse(suite);
        return null;
    }

    @Override
    public Object visitExpression(Expression node) throws Exception {
        if (my_scope.generator && node.getInternalBody() != null) {
            module.error("'return' with argument inside generator", true, node);
        }
        return visitReturn(new Return(node, node.getInternalBody()), true);
    }

    public void loadArray(Code code, java.util.List<? extends PythonTree> nodes) throws Exception {
        final int n;

        if (nodes == null) {
            n = 0;
        } else {
            n = nodes.size();
        }

        if (n == 0) {
            code.getstatic(p(Py.class), "EmptyObjects", ci(PyObject[].class));
            return;
        } else if (module.emitPrimitiveArraySetters(nodes, code)) {
            return;
        }
        code.iconst(n);
        code.anewarray(p(PyObject.class));
        for (int i = 0; i < n; i++) {
            code.dup();
            code.iconst(i);
            visit(nodes.get(i));
            code.aastore();
        }
    }

    public int makeArray(java.util.List<? extends PythonTree> nodes) throws Exception {
        final int n;

        if (nodes == null) {
            n = 0;
        } else {
            n = nodes.size();
        }

        int array = code.getLocal(ci(PyObject[].class));
        if (n == 0) {
            code.getstatic(p(Py.class), "EmptyObjects", ci(PyObject[].class));
            code.astore(array);
        } else {
            code.iconst(n);
            code.anewarray(p(PyObject.class));
            code.astore(array);

            for (int i = 0; i < n; i++) {
                visit(nodes.get(i));
                code.aload(array);
                code.swap();
                code.iconst(i);
                code.swap();
                code.aastore();
            }
        }
        return array;
    }

    // nulls out an array of references
    public void freeArray(int array) {
        code.aload(array);
        code.aconst_null();
        code.invokestatic(p(Arrays.class), "fill", sig(Void.TYPE, Object[].class, Object.class));
        code.freeLocal(array);
    }

    public void freeArrayRef(int array) {
        code.aconst_null();
        code.astore(array);
        code.freeLocal(array);
    }

    public Str getDocStr(java.util.List<stmt> suite) {
        if (suite.size() > 0) {
            stmt stmt = suite.get(0);
            if (stmt instanceof Expr && ((Expr)stmt).getInternalValue() instanceof Str) {
                return (Str)((Expr)stmt).getInternalValue();
            }
        }
        return null;
    }

    public boolean makeClosure(ScopeInfo scope) throws Exception {
        if (scope == null || scope.freevars == null) {
            return false;
        }
        int n = scope.freevars.size();
        if (n == 0) {
            return false;
        }

        int tmp = code.getLocal(ci(PyObject[].class));
        code.iconst(n);
        code.anewarray(p(PyObject.class));
        code.astore(tmp);
        Map<String, SymInfo> upTbl = scope.up.tbl;
        for (int i = 0; i < n; i++) {
            code.aload(tmp);
            code.iconst(i);
            loadFrame();
            for (int j = 1; j < scope.distance; j++) {
                loadf_back();
            }
            SymInfo symInfo = upTbl.get(scope.freevars.elementAt(i));
            code.iconst(symInfo.env_index);
            code.invokevirtual(p(PyFrame.class), "getclosure", sig(PyObject.class, Integer.TYPE));
            code.aastore();
        }

        code.aload(tmp);
        code.freeLocal(tmp);

        return true;
    }

    @Override
    public Object visitFunctionDef(FunctionDef node) throws Exception {
        String name = getName(node.getInternalName());

        setline(node);

        ScopeInfo scope = module.getScopeInfo(node);

        // NOTE: this is attached to the constructed PyFunction, so it cannot be nulled out
        // with freeArray, unlike other usages of makeArray here
        int defaults = makeArray(scope.ac.getDefaults());

        code.new_(p(PyFunction.class));
        code.dup();
        loadFrame();
        code.getfield(p(PyFrame.class), "f_globals", ci(PyObject.class));
        code.aload(defaults);
        code.freeLocal(defaults);

        scope.setup_closure();
        scope.dump();
        module.codeConstant(new Suite(node, node.getInternalBody()), name, true, className, false,
                false, node.getLine(), scope, cflags).get(code);

        Str docStr = getDocStr(node.getInternalBody());
        if (docStr != null) {
            visit(docStr);
        } else {
            code.aconst_null();
        }

        if (!makeClosure(scope)) {
            code.invokespecial(p(PyFunction.class), "<init>",
                    sig(Void.TYPE, PyObject.class, PyObject[].class, PyCode.class, PyObject.class));
        } else {
            code.invokespecial(
                    p(PyFunction.class),
                    "<init>",
                    sig(Void.TYPE, PyObject.class, PyObject[].class, PyCode.class, PyObject.class,
                            PyObject[].class));
        }

        applyDecorators(node.getInternalDecorator_list());

        set(new Name(node, node.getInternalName(), expr_contextType.Store));
        return null;
    }

    private void applyDecorators(java.util.List<expr> decorators) throws Exception {
        if (decorators != null && !decorators.isEmpty()) {
            int res = storeTop();
            for (expr decorator : decorators) {
                visit(decorator);
                stackProduce();
            }
            for (int i = decorators.size(); i > 0; i--) {
                stackConsume();
                loadThreadState();
                code.aload(res);
                code.invokevirtual(p(PyObject.class), "__call__",
                        sig(PyObject.class, ThreadState.class, PyObject.class));
                code.astore(res);
            }
            code.aload(res);
            code.freeLocal(res);
        }
    }

    @Override
    public Object visitExpr(Expr node) throws Exception {
        setline(node);
        visit(node.getInternalValue());

        if (print_results) {
            code.invokestatic(p(Py.class), "printResult", sig(Void.TYPE, PyObject.class));
        } else {
            code.pop();
        }
        return null;
    }

    @Override
    public Object visitAssign(Assign node) throws Exception {
        setline(node);
        visit(node.getInternalValue());
        if (node.getInternalTargets().size() == 1) {
            set(node.getInternalTargets().get(0));
        } else {
            int tmp = storeTop();
            for (expr target : node.getInternalTargets()) {
                set(target, tmp);
            }
            code.freeLocal(tmp);
        }
        return null;
    }

    @Override
    public Object visitPrint(Print node) throws Exception {
        setline(node);
        int tmp = -1;

        if (node.getInternalDest() != null) {
            visit(node.getInternalDest());
            tmp = storeTop();
        }
        if (node.getInternalValues() == null || node.getInternalValues().size() == 0) {
            if (node.getInternalDest() != null) {
                code.aload(tmp);
                code.invokestatic(p(Py.class), "printlnv", sig(Void.TYPE, PyObject.class));
            } else {
                code.invokestatic(p(Py.class), "println", sig(Void.TYPE));
            }
        } else {
            for (int i = 0; i < node.getInternalValues().size(); i++) {
                if (node.getInternalDest() != null) {
                    code.aload(tmp);
                    visit(node.getInternalValues().get(i));
                    if (node.getInternalNl() && i == node.getInternalValues().size() - 1) {
                        code.invokestatic(p(Py.class), "println",
                                sig(Void.TYPE, PyObject.class, PyObject.class));
                    } else {
                        code.invokestatic(p(Py.class), "printComma",
                                sig(Void.TYPE, PyObject.class, PyObject.class));
                    }
                } else {
                    visit(node.getInternalValues().get(i));
                    if (node.getInternalNl() && i == node.getInternalValues().size() - 1) {
                        code.invokestatic(p(Py.class), "println", sig(Void.TYPE, PyObject.class));
                    } else {
                        code.invokestatic(p(Py.class), "printComma", sig(Void.TYPE, PyObject.class));
                    }

                }
            }
        }
        if (node.getInternalDest() != null) {
            code.freeLocal(tmp);
        }
        return null;
    }

    @Override
    public Object visitDelete(Delete node) throws Exception {
        setline(node);
        traverse(node);
        return null;
    }

    @Override
    public Object visitPass(Pass node) throws Exception {
        setline(node);
        return null;
    }

    @Override
    public Object visitBreak(Break node) throws Exception {
        // setline(node); Not needed here...
        if (breakLabels.empty()) {
            throw new ParseException("'break' outside loop", node);
        }

        doFinallysDownTo(bcfLevel);

        code.goto_(breakLabels.peek());
        return null;
    }

    @Override
    public Object visitContinue(Continue node) throws Exception {
        // setline(node); Not needed here...
        if (continueLabels.empty()) {
            throw new ParseException("'continue' not properly in loop", node);
        }

        doFinallysDownTo(bcfLevel);

        code.goto_(continueLabels.peek());
        return Exit;
    }

    @Override
    public Object visitYield(Yield node) throws Exception {
        setline(node);
        if (!fast_locals) {
            throw new ParseException("'yield' outside function", node);
        }

        int stackState = saveStack();

        if (node.getInternalValue() != null) {
            visit(node.getInternalValue());
        } else {
            getNone();
        }

        setLastI(++yield_count);

        saveLocals();
        code.areturn();

        Label restart = new Label();
        yields.addElement(restart);
        code.label(restart);
        restoreLocals();
        restoreStack(stackState);

        loadFrame();
        code.invokevirtual(p(PyFrame.class), "getGeneratorInput", sig(Object.class));
        code.dup();
        code.instanceof_(p(PyException.class));
        Label done2 = new Label();
        code.ifeq(done2);
        code.checkcast(p(Throwable.class));
        code.athrow();
        code.label(done2);
        code.checkcast(p(PyObject.class));

        return null;
    }

    private void stackProduce() {
        stackProduce(p(PyObject.class));
    }

    private void stackProduce(String signature) {
        stack.push(signature);
    }

    private void stackConsume() {
        stackConsume(1);
    }

    private void stackConsume(int numItems) {
        for (int i = 0; i < numItems; i++) {
            stack.pop();
        }
    }

    private int saveStack() throws Exception {
        if (stack.size() > 0) {
            int array = code.getLocal(ci(Object[].class));
            code.iconst(stack.size());
            code.anewarray(p(Object.class));
            code.astore(array);
            ListIterator<String> content = stack.listIterator(stack.size());
            for (int i = 0; content.hasPrevious(); i++) {
                String signature = content.previous();
                if (p(ThreadState.class).equals(signature)) {
                    // Stack: ... threadstate
                    code.pop();
                    // Stack: ...
                } else {
                    code.aload(array);
                    // Stack: |- ... value array
                    code.swap();
                    code.iconst(i++);
                    code.swap();
                    // Stack: |- ... array index value
                    code.aastore();
                    // Stack: |- ...
                }
            }
            return array;
        } else {
            return -1;
        }
    }

    private void restoreStack(int array) throws Exception {
        if (stack.size() > 0) {
            int i = stack.size() - 1;
            for (String signature : stack) {
                if (p(ThreadState.class).equals(signature)) {
                    loadThreadState();
                } else {
                    code.aload(array);
                    // Stack: |- ... array
                    code.iconst(i--);
                    code.aaload();
                    // Stack: |- ... value
                    code.checkcast(signature);
                }
            }
            code.freeLocal(array);
        }
    }

    private void restoreLocals() throws Exception {
        endExceptionHandlers();

        Vector<String> v = code.getActiveLocals();

        loadFrame();
        code.getfield(p(PyFrame.class), "f_savedlocals", ci(Object[].class));

        int locals = code.getLocal(ci(Object[].class));
        code.astore(locals);

        for (int i = 0; i < v.size(); i++) {
            String type = v.elementAt(i);
            if (type == null) {
                continue;
            }
            code.aload(locals);
            code.iconst(i);
            code.aaload();
            code.checkcast(type);
            code.astore(i);
        }
        code.freeLocal(locals);

        restartExceptionHandlers();
    }

    /**
     * Close all the open exception handler ranges. This should be paired with
     * restartExceptionHandlers to delimit internal code that shouldn't be handled by user handlers.
     * This allows us to set variables without the verifier thinking we might jump out of our
     * handling with an exception.
     */
    private void endExceptionHandlers() {
        Label end = new Label();
        code.label(end);
        for (int i = 0; i < exceptionHandlers.size(); ++i) {
            ExceptionHandler handler = exceptionHandlers.elementAt(i);
            handler.exceptionEnds.addElement(end);
        }
    }

    private void restartExceptionHandlers() {
        Label start = new Label();
        code.label(start);
        for (int i = 0; i < exceptionHandlers.size(); ++i) {
            ExceptionHandler handler = exceptionHandlers.elementAt(i);
            handler.exceptionStarts.addElement(start);
        }
    }

    private void saveLocals() throws Exception {
        Vector<String> v = code.getActiveLocals();
        code.iconst(v.size());
        code.anewarray(p(Object.class));
        int locals = code.getLocal(ci(Object[].class));
        code.astore(locals);

        for (int i = 0; i < v.size(); i++) {
            String type = v.elementAt(i);
            if (type == null) {
                continue;
            }
            code.aload(locals);
            code.iconst(i);
            // code.checkcast(code.pool.Class(p(Object.class)));
            if (i == 2222) {
                code.aconst_null();
            } else {
                code.aload(i);
            }
            code.aastore();
        }

        loadFrame();
        code.aload(locals);
        code.putfield(p(PyFrame.class), "f_savedlocals", ci(Object[].class));
        code.freeLocal(locals);
    }

    @Override
    public Object visitReturn(Return node) throws Exception {
        return visitReturn(node, false);
    }

    public Object visitReturn(Return node, boolean inEval) throws Exception {
        setline(node);
        if (!inEval && !fast_locals) {
            throw new ParseException("'return' outside function", node);
        }
        int tmp = 0;
        if (node.getInternalValue() != null) {
            if (my_scope.generator && !(node instanceof LambdaSyntheticReturn)) {
                throw new ParseException("'return' with argument " + "inside generator", node);
            }
            visit(node.getInternalValue());
            tmp = code.getReturnLocal();
            code.astore(tmp);
        }
        doFinallysDownTo(0);

        setLastI(-1);

        if (node.getInternalValue() != null) {
            code.aload(tmp);
        } else {
            getNone();
        }
        code.areturn();
        return Exit;
    }

    @Override
    public Object visitRaise(Raise node) throws Exception {
        setline(node);
        if (node.getInternalType() != null) {
            visit(node.getInternalType());
            stackProduce();
        }
        if (node.getInternalInst() != null) {
            visit(node.getInternalInst());
            stackProduce();
        }
        if (node.getInternalTback() != null) {
            visit(node.getInternalTback());
            stackProduce();
        }
        if (node.getInternalType() == null) {
            code.invokestatic(p(Py.class), "makeException", sig(PyException.class));
        } else if (node.getInternalInst() == null) {
            stackConsume();
            code.invokestatic(p(Py.class), "makeException", sig(PyException.class, PyObject.class));
        } else if (node.getInternalTback() == null) {
            stackConsume(2);
            code.invokestatic(p(Py.class), "makeException",
                    sig(PyException.class, PyObject.class, PyObject.class));
        } else {
            stackConsume(3);
            code.invokestatic(p(Py.class), "makeException",
                    sig(PyException.class, PyObject.class, PyObject.class, PyObject.class));
        }
        code.athrow();
        return Exit;
    }

    /**
     * Return the implied import level, which is different from the argument only if the argument is
     * zero (no leading dots) meaning try relative then absolute (in Python 2), signified by
     * returning level <code>-1</code>.
     */
    private int impliedImportLevel(int level) {
        // already prepared for a future change of DEFAULT_LEVEL
        // TODO: remove the compatibility code
        if (imp.DEFAULT_LEVEL == 0 || level != 0 || module.getFutures().isAbsoluteImportOn()) {
            return level;
        } else {
            return imp.DEFAULT_LEVEL;
        }
    }

    @Override
    public Object visitImport(Import node) throws Exception {
        setline(node);
        for (alias a : node.getInternalNames()) {
            String asname = null;
            if (a.getInternalAsname() != null) {
                String name = a.getInternalName();
                asname = a.getInternalAsname();
                code.ldc(name);
                loadFrame();
                code.iconst(impliedImportLevel(0));
                code.invokestatic(p(imp.class), "importOneAs",
                        sig(PyObject.class, String.class, PyFrame.class, Integer.TYPE));
            } else {
                String name = a.getInternalName();
                asname = name;
                if (asname.indexOf('.') > 0) {
                    asname = asname.substring(0, asname.indexOf('.'));
                }
                code.ldc(name);
                loadFrame();
                code.iconst(impliedImportLevel(0));
                code.invokestatic(p(imp.class), "importOne",
                        sig(PyObject.class, String.class, PyFrame.class, Integer.TYPE));
            }
            set(new Name(a, asname, expr_contextType.Store));
        }
        return null;
    }

    @Override
    public Object visitImportFrom(ImportFrom node) throws Exception {
        Future.checkFromFuture(node); // future stmt support
        setline(node);
        code.ldc(node.getInternalModule());
        java.util.List<alias> aliases = node.getInternalNames();
        if (aliases == null || aliases.size() == 0) {
            throw new ParseException("Internel parser error", node);
        } else if (aliases.size() == 1 && aliases.get(0).getInternalName().equals("*")) {
            if (my_scope.func_level > 0) {
                module.error("import * only allowed at module level", false, node);

                if (my_scope.contains_ns_free_vars) {
                    module.error("import * is not allowed in function '" + my_scope.scope_name
                            + "' because it contains a nested function with free variables", true,
                            node);
                }
            }
            if (my_scope.func_level > 1) {
                module.error("import * is not allowed in function '" + my_scope.scope_name
                        + "' because it is a nested function", true, node);
            }

            loadFrame();
            code.iconst(impliedImportLevel(node.getInternalLevel()));
            code.invokestatic(p(imp.class), "importAll",
                    sig(Void.TYPE, String.class, PyFrame.class, Integer.TYPE));

        } else {
            java.util.List<String> fromNames = new ArrayList<String>(); // [names.size()];
            java.util.List<String> asnames = new ArrayList<String>(); // [names.size()];
            for (int i = 0; i < aliases.size(); i++) {
                fromNames.add(aliases.get(i).getInternalName());
                asnames.add(aliases.get(i).getInternalAsname());
                if (asnames.get(i) == null) {
                    asnames.set(i, fromNames.get(i));
                }
            }
            int strArray = makeStrings(code, fromNames);
            code.aload(strArray);
            code.freeLocal(strArray);

            loadFrame();
            code.iconst(impliedImportLevel(node.getInternalLevel()));
            code.invokestatic(
                    p(imp.class),
                    "importFrom",
                    sig(PyObject[].class, String.class, String[].class, PyFrame.class, Integer.TYPE));
            int tmp = storeTop();
            for (int i = 0; i < aliases.size(); i++) {
                code.aload(tmp);
                code.iconst(i);
                code.aaload();
                set(new Name(aliases.get(i), asnames.get(i), expr_contextType.Store));
            }
            code.freeLocal(tmp);
        }
        return null;
    }

    @Override
    public Object visitGlobal(Global node) throws Exception {
        return null;
    }

    @Override
    public Object visitNonlocal(Nonlocal node) throws Exception {
        return null;
    }

    @Override
    public Object visitExec(Exec node) throws Exception {
        setline(node);
        visit(node.getInternalBody());
        stackProduce();

        if (node.getInternalGlobals() != null) {
            visit(node.getInternalGlobals());
        } else {
            code.aconst_null();
        }
        stackProduce();

        if (node.getInternalLocals() != null) {
            visit(node.getInternalLocals());
        } else {
            code.aconst_null();
        }
        stackProduce();

        // do the real work here
        stackConsume(3);
        code.invokestatic(p(Py.class), "exec",
                sig(Void.TYPE, PyObject.class, PyObject.class, PyObject.class));
        return null;
    }

    @Override
    public Object visitAssert(Assert node) throws Exception {
        setline(node);
        Label end_of_assert = new Label();

        /* First do an if __debug__: */
        loadFrame();
        emitGetGlobal("__debug__");

        code.invokevirtual(p(PyObject.class), "__bool__", sig(Boolean.TYPE));

        code.ifeq(end_of_assert);

        /*
         * Now do the body of the assert. If PyObject.__bool__ is true, then the assertion
         * succeeded, the message portion should not be processed. Otherwise, the message will be
         * processed.
         */
        visit(node.getInternalTest());
        code.invokevirtual(p(PyObject.class), "__bool__", sig(Boolean.TYPE));

        /* If evaluation is false, then branch to end of method */
        code.ifne(end_of_assert);

        /* Visit the message part of the assertion, or pass Py.None */
        if (node.getInternalMsg() != null) {
            visit(node.getInternalMsg());
        } else {
            getNone();
        }

        /* Push exception type onto stack(AssertionError) */
        loadFrame();
        emitGetGlobal("AssertionError");

        code.swap(); // The type is the first argument, but the message could be a yield

        code.invokestatic(p(Py.class), "makeException",
                sig(PyException.class, PyObject.class, PyObject.class));
        /* Raise assertion error. Only executes this logic if assertion failed */
        code.athrow();

        /* And finally set the label for the end of it all */
        code.label(end_of_assert);

        return null;
    }

    public Object doTest(Label end_of_if, If node, int index) throws Exception {
        Label end_of_suite = new Label();

        setline(node.getInternalTest());
        visit(node.getInternalTest());
        code.invokevirtual(p(PyObject.class), "__bool__", sig(Boolean.TYPE));

        code.ifeq(end_of_suite);

        Object exit = suite(node.getInternalBody());

        if (end_of_if != null && exit == null) {
            code.goto_(end_of_if);
        }

        code.label(end_of_suite);

        if (node.getInternalOrelse() != null) {
            return suite(node.getInternalOrelse()) != null ? exit : null;
        } else {
            return null;
        }
    }

    @Override
    public Object visitIf(If node) throws Exception {
        Label end_of_if = null;
        if (node.getInternalOrelse() != null) {
            end_of_if = new Label();
        }

        Object exit = doTest(end_of_if, node, 0);
        if (end_of_if != null) {
            code.label(end_of_if);
        }
        return exit;
    }

    @Override
    public Object visitIfExp(IfExp node) throws Exception {
        setline(node.getInternalTest());
        Label end = new Label();
        Label end_of_else = new Label();

        visit(node.getInternalTest());
        code.invokevirtual(p(PyObject.class), "__bool__", sig(Boolean.TYPE));

        code.ifeq(end_of_else);
        visit(node.getInternalBody());
        code.goto_(end);

        code.label(end_of_else);
        visit(node.getInternalOrelse());

        code.label(end);

        return null;
    }

    public int beginLoop() {
        continueLabels.push(new Label());
        breakLabels.push(new Label());
        int savebcf = bcfLevel;
        bcfLevel = exceptionHandlers.size();
        return savebcf;
    }

    public void finishLoop(int savebcf) {
        continueLabels.pop();
        breakLabels.pop();
        bcfLevel = savebcf;
    }

    @Override
    public Object visitWhile(While node) throws Exception {
        int savebcf = beginLoop();
        Label continue_loop = continueLabels.peek();
        Label break_loop = breakLabels.peek();

        Label start_loop = new Label();

        code.goto_(continue_loop);
        code.label(start_loop);

        // Do suite
        suite(node.getInternalBody());

        code.label(continue_loop);
        setline(node);

        // Do test
        visit(node.getInternalTest());
        code.invokevirtual(p(PyObject.class), "__bool__", sig(Boolean.TYPE));
        code.ifne(start_loop);

        finishLoop(savebcf);

        if (node.getInternalOrelse() != null) {
            // Do else
            suite(node.getInternalOrelse());
        }
        code.label(break_loop);

        // Probably need to detect "guaranteed exits"
        return null;
    }

    @Override
    public Object visitFor(For node) throws Exception {
        int savebcf = beginLoop();
        Label continue_loop = continueLabels.peek();
        Label break_loop = breakLabels.peek();
        Label start_loop = new Label();
        Label next_loop = new Label();

        setline(node);

        // parse the list
        visit(node.getInternalIter());

        int iter_tmp = code.getLocal(p(PyObject.class));
        int expr_tmp = code.getLocal(p(PyObject.class));

        // set up the loop iterator
        code.invokevirtual(p(PyObject.class), "__iter__", sig(PyObject.class));
        code.astore(iter_tmp);

        // do check at end of loop. Saves one opcode ;-)
        code.goto_(next_loop);

        code.label(start_loop);
        // set iter variable to current entry in list
        set(node.getInternalTarget(), expr_tmp);

        // evaluate for body
        suite(node.getInternalBody());

        code.label(continue_loop);

        code.label(next_loop);
        setline(node);
        // get the next element from the list
        code.aload(iter_tmp);
        code.invokevirtual(p(PyObject.class), "__iternext__", sig(PyObject.class));

        code.astore(expr_tmp);
        code.aload(expr_tmp);
        // if no more elements then fall through
        code.ifnonnull(start_loop);

        finishLoop(savebcf);

        if (node.getInternalOrelse() != null) {
            // Do else clause if provided
            suite(node.getInternalOrelse());
        }

        code.label(break_loop);

        code.freeLocal(iter_tmp);
        code.freeLocal(expr_tmp);

        // Probably need to detect "guaranteed exits"
        return null;
    }

    public void exceptionTest(int exc, Label end_of_exceptions, TryExcept node, int index)
            throws Exception {
        for (int i = 0; i < node.getInternalHandlers().size(); i++) {
            ExceptHandler handler = (ExceptHandler)node.getInternalHandlers().get(i);

            // setline(name);
            Label end_of_self = new Label();

            if (handler.getInternalType() != null) {
                code.aload(exc);
                // get specific exception
                visit(handler.getInternalType());
                code.invokevirtual(p(PyException.class), "match", sig(Boolean.TYPE, PyObject.class));
                code.ifeq(end_of_self);
            } else {
                if (i != node.getInternalHandlers().size() - 1) {
                    throw new ParseException("default 'except:' must be last", handler);
                }
            }

            if (handler.getInternalName() != null) {
                code.aload(exc);
                code.getfield(p(PyException.class), "value", ci(PyObject.class));
                set(handler.getInternalName());
            }

            // do exception body
            suite(handler.getInternalBody());
            code.goto_(end_of_exceptions);
            code.label(end_of_self);
        }
        code.aload(exc);
        code.athrow();
    }

    @Override
    public Object visitTryFinally(TryFinally node) throws Exception {
        Label start = new Label();
        Label end = new Label();
        Label handlerStart = new Label();
        Label finallyEnd = new Label();

        Object ret;

        ExceptionHandler inFinally = new ExceptionHandler(node);

        // Do protected suite
        exceptionHandlers.push(inFinally);

        int excLocal = code.getLocal(p(Throwable.class));
        code.aconst_null();
        code.astore(excLocal);

        code.label(start);
        inFinally.exceptionStarts.addElement(start);

        ret = suite(node.getInternalBody());

        code.label(end);
        inFinally.exceptionEnds.addElement(end);
        inFinally.bodyDone = true;

        exceptionHandlers.pop();

        if (ret == NoExit) {
            inlineFinally(inFinally);
            code.goto_(finallyEnd);
        }

        // Handle any exceptions that get thrown in suite
        code.label(handlerStart);
        code.astore(excLocal);

        code.aload(excLocal);
        loadFrame();

        code.invokestatic(p(Py.class), "addTraceback",
                sig(Void.TYPE, Throwable.class, PyFrame.class));

        inlineFinally(inFinally);
        code.aload(excLocal);
        code.checkcast(p(Throwable.class));
        code.athrow();

        code.label(finallyEnd);

        code.freeLocal(excLocal);

        inFinally.addExceptionHandlers(handlerStart);
        // According to any JVM verifiers, this code block might not return
        return null;
    }

    private void inlineFinally(ExceptionHandler handler) throws Exception {
        if (!handler.bodyDone) {
            // end the previous exception block so inlined finally code doesn't
            // get covered by our exception handler.
            Label end = new Label();
            code.label(end);
            handler.exceptionEnds.addElement(end);
            // also exiting the try: portion of this particular finally
        }
        if (handler.isFinallyHandler()) {
            handler.finalBody(this);
        }
    }

    private void reenterProtectedBody(ExceptionHandler handler) throws Exception {
        // restart exception coverage
        Label restart = new Label();
        code.label(restart);
        handler.exceptionStarts.addElement(restart);
    }

    /**
     * Inline the finally handling code for levels down to the levelth parent (0 means all). This
     * takes care to avoid having more nested finallys catch exceptions throw by the parent finally
     * code. This also pops off all the handlers above level temporarily.
     */
    private void doFinallysDownTo(int level) throws Exception {
        Stack<ExceptionHandler> poppedHandlers = new Stack<ExceptionHandler>();
        while (exceptionHandlers.size() > level) {
            ExceptionHandler handler = exceptionHandlers.pop();
            inlineFinally(handler);
            poppedHandlers.push(handler);
        }
        while (poppedHandlers.size() > 0) {
            ExceptionHandler handler = poppedHandlers.pop();
            reenterProtectedBody(handler);
            exceptionHandlers.push(handler);
        }
    }

    @Override
    public Object visitTryExcept(TryExcept node) throws Exception {
        Label start = new Label();
        Label end = new Label();
        Label handler_start = new Label();
        Label handler_end = new Label();
        ExceptionHandler handler = new ExceptionHandler();

        code.label(start);
        handler.exceptionStarts.addElement(start);
        exceptionHandlers.push(handler);
        // Do suite
        Object exit = suite(node.getInternalBody());
        exceptionHandlers.pop();
        code.label(end);
        handler.exceptionEnds.addElement(end);

        if (exit == null) {
            code.goto_(handler_end);
        }

        code.label(handler_start);

        loadFrame();

        code.invokestatic(p(Py.class), "setException",
                sig(PyException.class, Throwable.class, PyFrame.class));

        int exc = code.getFinallyLocal(p(Throwable.class));
        code.astore(exc);

        if (node.getInternalOrelse() == null) {
            // No else clause to worry about
            exceptionTest(exc, handler_end, node, 1);
            code.label(handler_end);
        } else {
            // Have else clause
            Label else_end = new Label();
            exceptionTest(exc, else_end, node, 1);
            code.label(handler_end);

            // do else clause
            suite(node.getInternalOrelse());
            code.label(else_end);
        }

        code.freeFinallyLocal(exc);
        handler.addExceptionHandlers(handler_start);
        return null;
    }

    @Override
    public Object visitSuite(Suite node) throws Exception {
        return suite(node.getInternalBody());
    }

    public Object suite(java.util.List<stmt> stmts) throws Exception {
        for (stmt s : stmts) {
            Object exit = visit(s);
            if (exit != null) {
                return Exit;
            }
        }
        return null;
    }

    @Override
    public Object visitBoolOp(BoolOp node) throws Exception {
        Label end = new Label();
        visit(node.getInternalValues().get(0));
        for (int i = 1; i < node.getInternalValues().size(); i++) {
            code.dup();
            code.invokevirtual(p(PyObject.class), "__bool__", sig(Boolean.TYPE));
            switch (node.getInternalOp()) {
                case Or:
                    code.ifne(end);
                    break;
                case And:
                    code.ifeq(end);
                    break;
            }
            code.pop();
            visit(node.getInternalValues().get(i));
        }
        code.label(end);
        return null;
    }

    @Override
    public Object visitCompare(Compare node) throws Exception {
        int last = code.getLocal(p(PyObject.class));
        int result = code.getLocal(p(PyObject.class));
        Label end = new Label();

        visit(node.getInternalLeft());
        code.astore(last);

        int n = node.getInternalOps().size();
        for (int i = 0; i < n - 1; i++) {
            visit(node.getInternalComparators().get(i));
            code.aload(last);
            code.swap();
            code.dup();
            code.astore(last);
            visitCmpop(node.getInternalOps().get(i));
            code.dup();
            code.astore(result);
            code.invokevirtual(p(PyObject.class), "__bool__", sig(Boolean.TYPE));
            code.ifeq(end);
        }

        visit(node.getInternalComparators().get(n - 1));
        code.aload(last);
        code.swap();
        visitCmpop(node.getInternalOps().get(n - 1));

        if (n > 1) {
            code.astore(result);
            code.label(end);
            code.aload(result);
        }

        code.aconst_null();
        code.astore(last);
        code.freeLocal(last);
        code.freeLocal(result);
        return null;
    }

    public void visitCmpop(cmpopType op) throws Exception {
        String name = null;
        switch (op) {
            case Eq:
                name = "_eq";
                break;
            case NotEq:
                name = "_ne";
                break;
            case Lt:
                name = "_lt";
                break;
            case LtE:
                name = "_le";
                break;
            case Gt:
                name = "_gt";
                break;
            case GtE:
                name = "_ge";
                break;
            case Is:
                name = "_is";
                break;
            case IsNot:
                name = "_isnot";
                break;
            case In:
                name = "_in";
                break;
            case NotIn:
                name = "_notin";
                break;
        }
        code.invokevirtual(p(PyObject.class), name, sig(PyObject.class, PyObject.class));
    }

    @Override
    public Object visitBinOp(BinOp node) throws Exception {
        visit(node.getInternalLeft());
        stackProduce();
        visit(node.getInternalRight());
        stackConsume();
        String name = null;
        switch (node.getInternalOp()) {
            case Add:
                name = "_add";
                break;
            case Sub:
                name = "_sub";
                break;
            case Mult:
                name = "_mul";
                break;
            case MatMult:
                name = "_matmul";
                break;
            case Div:
                name = "_div";
                break;
            case Mod:
                name = "_mod";
                break;
            case Pow:
                name = "_pow";
                break;
            case LShift:
                name = "_lshift";
                break;
            case RShift:
                name = "_rshift";
                break;
            case BitOr:
                name = "_or";
                break;
            case BitXor:
                name = "_xor";
                break;
            case BitAnd:
                name = "_and";
                break;
            case FloorDiv:
                name = "_floordiv";
                break;
        }

        if (node.getInternalOp() == operatorType.Div && module.getFutures().areDivisionOn()) {
            name = "_truediv";
        }
        code.invokevirtual(p(PyObject.class), name, sig(PyObject.class, PyObject.class));
        return null;
    }

    @Override
    public Object visitUnaryOp(UnaryOp node) throws Exception {
        visit(node.getInternalOperand());
        String name = null;
        switch (node.getInternalOp()) {
            case Invert:
                name = "__invert__";
                break;
            case Not:
                name = "__not__";
                break;
            case UAdd:
                name = "__pos__";
                break;
            case USub:
                name = "__neg__";
                break;
        }
        code.invokevirtual(p(PyObject.class), name, sig(PyObject.class));
        return null;
    }

    @Override
    public Object visitAugAssign(AugAssign node) throws Exception {
        setline(node);

        augmode = expr_contextType.Load;
        visit(node.getInternalTarget());
        int target = storeTop();

        visit(node.getInternalValue());

        code.aload(target);
        code.swap();
        String name = null;
        switch (node.getInternalOp()) {
            case Add:
                name = "_iadd";
                break;
            case Sub:
                name = "_isub";
                break;
            case Mult:
                name = "_imul";
                break;
            case MatMult:
                name = "_imatmul";
                break;
            case Div:
                name = "_idiv";
                break;
            case Mod:
                name = "_imod";
                break;
            case Pow:
                name = "_ipow";
                break;
            case LShift:
                name = "_ilshift";
                break;
            case RShift:
                name = "_irshift";
                break;
            case BitOr:
                name = "_ior";
                break;
            case BitXor:
                name = "_ixor";
                break;
            case BitAnd:
                name = "_iand";
                break;
            case FloorDiv:
                name = "_ifloordiv";
                break;
        }
        if (node.getInternalOp() == operatorType.Div && module.getFutures().areDivisionOn()) {
            name = "_itruediv";
        }
        code.invokevirtual(p(PyObject.class), name, sig(PyObject.class, PyObject.class));
        code.freeLocal(target);

        temporary = storeTop();
        augmode = expr_contextType.Store;
        visit(node.getInternalTarget());
        code.freeLocal(temporary);

        return null;
    }

    static int makeStrings(Code c, Collection<String> names) throws IOException {
        if (names != null) {
            c.iconst(names.size());
        } else {
            c.iconst_0();
        }
        c.anewarray(p(String.class));
        int strings = c.getLocal(ci(String[].class));
        c.astore(strings);
        if (names != null) {
            int i = 0;
            for (String name : names) {
                c.aload(strings);
                c.iconst(i);
                c.ldc(name);
                c.aastore();
                i++;
            }
        }
        return strings;
    }

    public Object invokeNoKeywords(Attribute node, java.util.List<expr> values) throws Exception {
        String name = getName(node.getInternalAttr());
        visit(node.getInternalValue());
        stackProduce();
        code.ldc(name);
        code.invokevirtual(p(PyObject.class), "__getattr__", sig(PyObject.class, String.class));
        loadThreadState();
        stackProduce(p(ThreadState.class));

        switch (values.size()) {
            case 0:
                stackConsume(2); // target + ts
                code.invokevirtual(p(PyObject.class), "__call__",
                        sig(PyObject.class, ThreadState.class));
                break;
            case 1:
                visit(values.get(0));
                stackConsume(2); // target + ts
                code.invokevirtual(p(PyObject.class), "__call__",
                        sig(PyObject.class, ThreadState.class, PyObject.class));
                break;
            case 2:
                visit(values.get(0));
                stackProduce();
                visit(values.get(1));
                stackConsume(3); // target + ts + arguments
                code.invokevirtual(p(PyObject.class), "__call__",
                        sig(PyObject.class, ThreadState.class, PyObject.class, PyObject.class));
                break;
            case 3:
                visit(values.get(0));
                stackProduce();
                visit(values.get(1));
                stackProduce();
                visit(values.get(2));
                stackConsume(4); // target + ts + arguments
                code.invokevirtual(
                        p(PyObject.class),
                        "__call__",
                        sig(PyObject.class, ThreadState.class, PyObject.class, PyObject.class,
                                PyObject.class));
                break;
            case 4:
                visit(values.get(0));
                stackProduce();
                visit(values.get(1));
                stackProduce();
                visit(values.get(2));
                stackProduce();
                visit(values.get(3));
                stackConsume(5); // target + ts + arguments
                code.invokevirtual(
                        p(PyObject.class),
                        "__call__",
                        sig(PyObject.class, ThreadState.class, PyObject.class, PyObject.class,
                                PyObject.class, PyObject.class));
                break;
            default:
                int argArray = makeArray(values);
                code.aload(argArray);
                code.freeLocal(argArray);
                stackConsume(2); // target + ts
                code.invokevirtual(p(PyObject.class), "__call__",
                        sig(PyObject.class, ThreadState.class, PyObject[].class));
                break;
        }
        return null;
    }

    @Override
    public Object visitCall(Call node) throws Exception {
        java.util.List<String> keys = new ArrayList<String>();
        java.util.List<expr> values = new ArrayList<expr>();
        for (int i = 0; i < node.getInternalArgs().size(); i++) {
            values.add(node.getInternalArgs().get(i));
        }
        for (int i = 0; i < node.getInternalKeywords().size(); i++) {
            keys.add(node.getInternalKeywords().get(i).getInternalArg());
            values.add(node.getInternalKeywords().get(i).getInternalValue());
        }

        if ((node.getInternalKeywords() == null || node.getInternalKeywords().size() == 0)
                && node.getInternalStarargs() == null && node.getInternalKwargs() == null
                && node.getInternalFunc() instanceof Attribute) {
            return invokeNoKeywords((Attribute)node.getInternalFunc(), values);
        }

        visit(node.getInternalFunc());
        stackProduce();

        if (node.getInternalStarargs() != null || node.getInternalKwargs() != null) {
            int argArray = makeArray(values);
            int strArray = makeStrings(code, keys);
            if (node.getInternalStarargs() == null) {
                code.aconst_null();
            } else {
                visit(node.getInternalStarargs());
            }
            stackProduce();
            if (node.getInternalKwargs() == null) {
                code.aconst_null();
            } else {
                visit(node.getInternalKwargs());
            }
            stackProduce();

            code.aload(argArray);
            code.aload(strArray);
            code.freeLocal(strArray);
            code.dup2_x2();
            code.pop2();

            stackConsume(3); // target + starargs + kwargs
            code.invokevirtual(
                    p(PyObject.class),
                    "_callextra",
                    sig(PyObject.class, PyObject[].class, String[].class, PyObject.class,
                            PyObject.class));
            freeArrayRef(argArray);
        } else if (keys.size() > 0) {
            loadThreadState();
            stackProduce(p(ThreadState.class));
            int argArray = makeArray(values);
            int strArray = makeStrings(code, keys);
            code.aload(argArray);
            code.aload(strArray);
            code.freeLocal(strArray);
            stackConsume(2); // target + ts
            code.invokevirtual(p(PyObject.class), "__call__",
                    sig(PyObject.class, ThreadState.class, PyObject[].class, String[].class));
            freeArrayRef(argArray);
        } else {
            loadThreadState();
            stackProduce(p(ThreadState.class));
            switch (values.size()) {
                case 0:
                    stackConsume(2); // target + ts
                    code.invokevirtual(p(PyObject.class), "__call__",
                            sig(PyObject.class, ThreadState.class));
                    break;
                case 1:
                    visit(values.get(0));
                    stackConsume(2); // target + ts
                    code.invokevirtual(p(PyObject.class), "__call__",
                            sig(PyObject.class, ThreadState.class, PyObject.class));
                    break;
                case 2:
                    visit(values.get(0));
                    stackProduce();
                    visit(values.get(1));
                    stackConsume(3); // target + ts + arguments
                    code.invokevirtual(p(PyObject.class), "__call__",
                            sig(PyObject.class, ThreadState.class, PyObject.class, PyObject.class));
                    break;
                case 3:
                    visit(values.get(0));
                    stackProduce();
                    visit(values.get(1));
                    stackProduce();
                    visit(values.get(2));
                    stackConsume(4); // target + ts + arguments
                    code.invokevirtual(
                            p(PyObject.class),
                            "__call__",
                            sig(PyObject.class, ThreadState.class, PyObject.class, PyObject.class,
                                    PyObject.class));
                    break;
                case 4:
                    visit(values.get(0));
                    stackProduce();
                    visit(values.get(1));
                    stackProduce();
                    visit(values.get(2));
                    stackProduce();
                    visit(values.get(3));
                    stackConsume(5); // target + ts + arguments
                    code.invokevirtual(
                            p(PyObject.class),
                            "__call__",
                            sig(PyObject.class, ThreadState.class, PyObject.class, PyObject.class,
                                    PyObject.class, PyObject.class));
                    break;
                default:
                    int argArray = makeArray(values);
                    code.aload(argArray);
                    code.freeLocal(argArray);
                    stackConsume(2); // target + ts
                    code.invokevirtual(p(PyObject.class), "__call__",
                            sig(PyObject.class, ThreadState.class, PyObject[].class));
                    break;
            }
        }
        return null;
    }

    public Object Slice(Subscript node, Slice slice) throws Exception {
        expr_contextType ctx = node.getInternalCtx();
        if (ctx == expr_contextType.AugStore && augmode == expr_contextType.Store) {
            restoreAugTmps(node, 4);
            ctx = expr_contextType.Store;
        } else {
            visit(node.getInternalValue());
            stackProduce();
            if (slice.getInternalLower() != null) {
                visit(slice.getInternalLower());
            } else {
                code.aconst_null();
            }
            stackProduce();
            if (slice.getInternalUpper() != null) {
                visit(slice.getInternalUpper());
            } else {
                code.aconst_null();
            }
            stackProduce();
            if (slice.getInternalStep() != null) {
                visit(slice.getInternalStep());
            } else {
                code.aconst_null();
            }
            stackProduce();

            if (node.getInternalCtx() == expr_contextType.AugStore
                    && augmode == expr_contextType.Load) {
                saveAugTmps(node, 4);
                ctx = expr_contextType.Load;
            }
            stackConsume(4);
        }

        switch (ctx) {
            case Del:
                code.invokevirtual(p(PyObject.class), "__delslice__",
                        sig(Void.TYPE, PyObject.class, PyObject.class, PyObject.class));
                return null;
            case Load:
                code.invokevirtual(p(PyObject.class), "__getslice__",
                        sig(PyObject.class, PyObject.class, PyObject.class, PyObject.class));
                return null;
            case Param:
            case Store:
                code.aload(temporary);
                code.invokevirtual(
                        p(PyObject.class),
                        "__setslice__",
                        sig(Void.TYPE, PyObject.class, PyObject.class, PyObject.class,
                                PyObject.class));
                return null;
        }
        return null;

    }

    @Override
    public Object visitSubscript(Subscript node) throws Exception {
        if (node.getInternalSlice() instanceof Slice) {
            return Slice(node, (Slice)node.getInternalSlice());
        }

        int value = temporary;
        expr_contextType ctx = node.getInternalCtx();
        if (node.getInternalCtx() == expr_contextType.AugStore && augmode == expr_contextType.Store) {
            restoreAugTmps(node, 2);
            ctx = expr_contextType.Store;
        } else {
            visit(node.getInternalValue());
            stackProduce();
            visit(node.getInternalSlice());
            stackConsume();

            if (node.getInternalCtx() == expr_contextType.AugStore
                    && augmode == expr_contextType.Load) {
                saveAugTmps(node, 2);
                ctx = expr_contextType.Load;
            }
        }

        switch (ctx) {
            case Del:
                code.invokevirtual(p(PyObject.class), "__delitem__", sig(Void.TYPE, PyObject.class));
                return null;
            case Load:
                code.invokevirtual(p(PyObject.class), "__getitem__",
                        sig(PyObject.class, PyObject.class));
                return null;
            case Param:
            case Store:
                code.aload(value);
                code.invokevirtual(p(PyObject.class), "__setitem__",
                        sig(Void.TYPE, PyObject.class, PyObject.class));
                return null;
        }
        return null;
    }

    @Override
    public Object visitIndex(Index node) throws Exception {
        traverse(node);
        return null;
    }

    @Override
    public Object visitExtSlice(ExtSlice node) throws Exception {
        int dims = makeArray(node.getInternalDims());
        code.new_(p(PyTuple.class));
        code.dup();
        code.aload(dims);
        code.invokespecial(p(PyTuple.class), "<init>", sig(Void.TYPE, PyObject[].class));
        freeArray(dims);
        return null;
    }

    @Override
    public Object visitAttribute(Attribute node) throws Exception {

        expr_contextType ctx = node.getInternalCtx();
        if (node.getInternalCtx() == expr_contextType.AugStore && augmode == expr_contextType.Store) {
            restoreAugTmps(node, 2);
            ctx = expr_contextType.Store;
        } else {
            visit(node.getInternalValue());
            code.ldc(getName(node.getInternalAttr()));

            if (node.getInternalCtx() == expr_contextType.AugStore
                    && augmode == expr_contextType.Load) {
                saveAugTmps(node, 2);
                ctx = expr_contextType.Load;
            }
        }

        switch (ctx) {
            case Del:
                code.invokevirtual(p(PyObject.class), "__delattr__", sig(Void.TYPE, String.class));
                return null;
            case Load:
                code.invokevirtual(p(PyObject.class), "__getattr__",
                        sig(PyObject.class, String.class));
                return null;
            case Param:
            case Store:
                code.aload(temporary);
                code.invokevirtual(p(PyObject.class), "__setattr__",
                        sig(Void.TYPE, String.class, PyObject.class));
                return null;
        }
        return null;
    }

    public Object seqSet(java.util.List<expr> nodes) throws Exception {
        return seqSet(nodes, nodes.size(), -1);
    }

    public Object seqSet(java.util.List<expr> nodes, int count, int countAfter) throws Exception {
        code.aload(temporary);
        code.iconst(count);
        code.iconst(countAfter);
        code.invokestatic(p(Py.class), "unpackIterator",
                sig(PyObject[].class, PyObject.class, Integer.TYPE, Integer.TYPE));

        int tmp = code.getLocal("[org/python/core/PyObject");
        code.astore(tmp);

        for (int i = 0; i < nodes.size(); i++) {
            code.aload(tmp);
            code.iconst(i);
            code.aaload();
            set(nodes.get(i));
        }
        code.freeLocal(tmp);

        return null;
    }

    public Object seqDel(java.util.List<expr> nodes) throws Exception {
        for (expr e : nodes) {
            visit(e);
        }
        return null;
    }

    private Object checkStarred(java.util.List<expr> elts, PythonTree node) throws Exception {
        boolean foundStarred = false;
        int count = elts.size();
        int countAfter = -1;
        for (int i=0; i<elts.size(); i++) {
            expr elt = elts.get(i);
            if (elt instanceof Starred) {
                if (!foundStarred) {
                    if (i >= 256) {
                            throw new ParseException("too many expressions in star-unpacking assignment", node);
                    }
                    count = i;
                    countAfter = elts.size()-i-1;
                    foundStarred = true;
                } else {
                    throw new ParseException("two starred expressions in assignment", node);
                }
            }
        }
        return seqSet(elts, count, countAfter);
    }

    @Override
    public Object visitTuple(Tuple node) throws Exception {
        if (node.getInternalCtx() == expr_contextType.Store) {
            return checkStarred(node.getInternalElts(), node);
        }

        if (node.getInternalCtx() == expr_contextType.Del) {
            return seqDel(node.getInternalElts());
        }

        if (my_scope.generator) {
            int content = makeArray(node.getInternalElts());
            code.new_(p(PyTuple.class));
            code.dup();
            code.aload(content);
            code.invokespecial(p(PyTuple.class), "<init>", sig(Void.TYPE, PyObject[].class));
            freeArray(content);
        } else {
            code.new_(p(PyTuple.class));
            code.dup();
            loadArray(code, node.getInternalElts());
            code.invokespecial(p(PyTuple.class), "<init>", sig(Void.TYPE, PyObject[].class));
        }
        return null;
    }

    @Override
    public Object visitList(List node) throws Exception {
        if (node.getInternalCtx() == expr_contextType.Store) {
            return checkStarred(node.getInternalElts(), node);
        }
        if (node.getInternalCtx() == expr_contextType.Del) {
            return seqDel(node.getInternalElts());
        }

        if (my_scope.generator) {
            int content = makeArray(node.getInternalElts());
            code.new_(p(PyList.class));
            code.dup();
            code.aload(content);
            code.invokespecial(p(PyList.class), "<init>", sig(Void.TYPE, PyObject[].class));
            freeArray(content);
        } else {
            code.new_(p(PyList.class));
            code.dup();
            loadArray(code, node.getInternalElts());
            code.invokespecial(p(PyList.class), "<init>", sig(Void.TYPE, PyObject[].class));
        }
        return null;
    }

    @Override
    public Object visitListComp(ListComp node) throws Exception {
        code.new_(p(PyList.class));

        code.dup();
        code.invokespecial(p(PyList.class), "<init>", sig(Void.TYPE));

        code.dup();

        code.ldc("append");

        code.invokevirtual(p(PyObject.class), "__getattr__", sig(PyObject.class, String.class));
        String tmp_append = "_[" + node.getLine() + "_" + node.getCharPositionInLine() + "]";

        java.util.List<expr> args = new ArrayList<expr>();
        args.add(node.getInternalElt());

        finishComp(node, args, node.getInternalGenerators(), tmp_append);

        return null;
    }

    @Override
    public Object visitSetComp(SetComp node) throws Exception {
        code.new_(p(PySet.class));
        code.dup();
        visitInternalGenerators(node, node.getInternalElt(), node.getInternalGenerators());
        code.invokespecial(p(PySet.class), "<init>", sig(Void.TYPE, PyObject.class));
        return null;
    }

    @Override
    public Object visitDictComp(DictComp node) throws Exception {
        code.new_(p(PyDictionary.class));
        code.dup();
        code.invokespecial(p(PyDictionary.class), "<init>", sig(Void.TYPE));
        code.dup();
        java.util.List<expr> kv = Arrays.asList(node.getInternalKey(), node.getInternalValue());
        visitInternalGenerators(node, new Tuple(node, kv, expr_contextType.UNDEFINED),
                node.getInternalGenerators());
        code.invokevirtual(p(PyDictionary.class), "update", sig(Void.TYPE, PyObject.class));
        return null;
    }

    private void finishComp(expr node, java.util.List<expr> args,
            java.util.List<comprehension> generators, String tmp_append) throws Exception {
        set(new Name(node, tmp_append, expr_contextType.Store));

        stmt n = new Expr(node, new Call(node, new Name(node, tmp_append, expr_contextType.Load), //
                args, new ArrayList<keyword>(), null, null));

        for (int i = generators.size() - 1; i >= 0; i--) {
            comprehension lc = generators.get(i);
            for (int j = lc.getInternalIfs().size() - 1; j >= 0; j--) {
                java.util.List<stmt> body = new ArrayList<stmt>();
                body.add(n);
                n = new If(lc.getInternalIfs().get(j), lc.getInternalIfs().get(j), body, //
                        new ArrayList<stmt>());
            }
            java.util.List<stmt> body = new ArrayList<stmt>();
            body.add(n);
            n = new For(lc, lc.getInternalTarget(), lc.getInternalIter(), body, //
                    new ArrayList<stmt>());
        }
        visit(n);
        java.util.List<expr> targets = new ArrayList<expr>();
        targets.add(new Name(n, tmp_append, expr_contextType.Del));
        visit(new Delete(n, targets));
    }

    @Override
    public Object visitDict(Dict node) throws Exception {
        java.util.List<PythonTree> elts = new ArrayList<PythonTree>();
        for (int i = 0; i < node.getInternalKeys().size(); i++) {
            elts.add(node.getInternalKeys().get(i));
            elts.add(node.getInternalValues().get(i));
        }

        if (my_scope.generator) {
            int content = makeArray(elts);
            code.new_(p(PyDictionary.class));
            code.dup();
            code.aload(content);
            code.invokespecial(p(PyDictionary.class), "<init>", sig(Void.TYPE, PyObject[].class));
            freeArray(content);
        } else {
            code.new_(p(PyDictionary.class));
            code.dup();
            loadArray(code, elts);
            code.invokespecial(p(PyDictionary.class), "<init>", sig(Void.TYPE, PyObject[].class));
        }
        return null;
    }

    @Override
    public Object visitSet(Set node) throws Exception {
        if (my_scope.generator) {
            int content = makeArray(node.getInternalElts());
            code.new_(p(PySet.class));
            code.dup();
            code.aload(content);
            code.invokespecial(p(PySet.class), "<init>", sig(Void.TYPE, PyObject[].class));
            freeArray(content);
        } else {
            code.new_(p(PySet.class));
            code.dup();
            loadArray(code, node.getInternalElts());
            code.invokespecial(p(PySet.class), "<init>", sig(Void.TYPE, PyObject[].class));
        }
        return null;
    }

    @Override
    public Object visitRepr(Repr node) throws Exception {
        visit(node.getInternalValue());
        code.invokevirtual(p(PyObject.class), "__repr__", sig(PyString.class));
        return null;
    }

    // a marker class to distinguish this usage; future generator rewriting may likely
    // want to remove this support
    private class LambdaSyntheticReturn extends Return {

        private LambdaSyntheticReturn(PythonTree tree, expr value) {
            super(tree, value);
        }
    }

    @Override
    public Object visitLambda(Lambda node) throws Exception {
        String name = "<lambda>";

        // Add a synthetic return node onto the outside of suite;
        java.util.List<stmt> bod = new ArrayList<stmt>();
        bod.add(new LambdaSyntheticReturn(node, node.getInternalBody()));
        mod retSuite = new Suite(node, bod);

        setline(node);

        ScopeInfo scope = module.getScopeInfo(node);

        int defaultsArray = makeArray(scope.ac.getDefaults());

        code.new_(p(PyFunction.class));

        code.dup();
        code.aload(defaultsArray);
        code.freeLocal(defaultsArray);

        loadFrame();
        code.getfield(p(PyFrame.class), "f_globals", ci(PyObject.class));

        code.swap();

        scope.setup_closure();
        scope.dump();
        module.codeConstant(retSuite, name, true, className, false, false, node.getLine(), scope,
                cflags).get(code);

        if (!makeClosure(scope)) {
            code.invokespecial(p(PyFunction.class), "<init>",
                    sig(Void.TYPE, PyObject.class, PyObject[].class, PyCode.class));
        } else {
            code.invokespecial(
                    p(PyFunction.class),
                    "<init>",
                    sig(Void.TYPE, PyObject.class, PyObject[].class, PyCode.class, PyObject[].class));
        }
        return null;
    }

    @Override
    public Object visitEllipsis(Ellipsis node) throws Exception {
        code.getstatic(p(Py.class), "Ellipsis", ci(PyObject.class));
        return null;
    }

    @Override
    public Object visitSlice(Slice node) throws Exception {
        if (node.getInternalLower() == null) {
            getNone();
        } else {
            visit(node.getInternalLower());
        }
        stackProduce();
        if (node.getInternalUpper() == null) {
            getNone();
        } else {
            visit(node.getInternalUpper());
        }
        stackProduce();
        if (node.getInternalStep() == null) {
            getNone();
        } else {
            visit(node.getInternalStep());
        }
        int step = storeTop();
        stackConsume(2);

        code.new_(p(PySlice.class));
        code.dup();
        code.dup2_x2();
        code.pop2();

        code.aload(step);
        code.freeLocal(step);

        code.invokespecial(p(PySlice.class), "<init>",
                sig(Void.TYPE, PyObject.class, PyObject.class, PyObject.class));
        return null;
    }

    @Override
    public Object visitClassDef(ClassDef node) throws Exception {
        setline(node);

        int baseArray = makeArray(node.getInternalBases());

        // Get class name
        String name = getName(node.getInternalName());
        code.ldc(name);

        code.aload(baseArray);

        ScopeInfo scope = module.getScopeInfo(node);

        scope.setup_closure();
        scope.dump();
        // Make code object out of suite

        module.codeConstant(new Suite(node, node.getInternalBody()), name, false, name,
                getDocStr(node.getInternalBody()), true, false, node.getLine(), scope, cflags).get(
                code);

        // Make class out of name, bases, and code
        if (!makeClosure(scope)) {
            code.invokestatic(p(Py.class), "makeClass",
                    sig(PyObject.class, String.class, PyObject[].class, PyCode.class));
        } else {
            code.invokestatic(
                    p(Py.class),
                    "makeClass",
                    sig(PyObject.class, String.class, PyObject[].class, PyCode.class,
                            PyObject[].class));
        }

        applyDecorators(node.getInternalDecorator_list());

        // Assign this new class to the given name
        set(new Name(node, node.getInternalName(), expr_contextType.Store));
        freeArray(baseArray);
        return null;
    }

    @Override
    public Object visitNum(Num node) throws Exception {
        if (node.getInternalN() instanceof PyInteger) {
            module.integerConstant(((PyInteger)node.getInternalN()).getValue()).get(code);
        } else if (node.getInternalN() instanceof PyLong) {
            module.longConstant(((PyObject)node.getInternalN()).__str__().toString()).get(code);
        } else if (node.getInternalN() instanceof PyFloat) {
            module.floatConstant(((PyFloat)node.getInternalN()).getValue()).get(code);
        } else if (node.getInternalN() instanceof PyComplex) {
            module.complexConstant(((PyComplex)node.getInternalN()).imag).get(code);
        }
        return null;
    }

    private String getName(String name) {
        if (className != null && name.startsWith("__") && !name.endsWith("__")) {
            // remove leading '_' from classname
            int i = 0;
            while (className.charAt(i) == '_') {
                i++;
            }
            return "_" + className.substring(i) + name;
        }
        return name;
    }

    void emitGetGlobal(String name) throws Exception {
        code.ldc(name);
        code.invokevirtual(p(PyFrame.class), "getglobal", sig(PyObject.class, String.class));
    }

    @Override
    public Object visitStarred(Starred node) throws Exception {
        visit(node.getInternalValue());
        return null;
    }

    @Override
    public Object visitName(Name node) throws Exception {
        String name;
        if (fast_locals) {
            name = node.getInternalId();
        } else {
            name = getName(node.getInternalId());
        }

        SymInfo syminf = tbl.get(name);

        expr_contextType ctx = node.getInternalCtx();
        if (ctx == expr_contextType.AugStore) {
            ctx = augmode;
        }

        switch (ctx) {
            case Load:
                loadFrame();
                if (syminf != null) {
                    int flags = syminf.flags;
                    if ((flags & ScopeInfo.GLOBAL) != 0 || optimizeGlobals
                            && (flags & (ScopeInfo.BOUND | ScopeInfo.CELL | ScopeInfo.FREE)) == 0) {
                        emitGetGlobal(name);
                        return null;
                    }
                    if (fast_locals) {
                        if ((flags & ScopeInfo.CELL) != 0) {
                            code.iconst(syminf.env_index);
                            code.invokevirtual(p(PyFrame.class), "getderef",
                                    sig(PyObject.class, Integer.TYPE));
                            return null;
                        }
                        if ((flags & ScopeInfo.BOUND) != 0) {
                            code.iconst(syminf.locals_index);
                            code.invokevirtual(p(PyFrame.class), "getlocal",
                                    sig(PyObject.class, Integer.TYPE));
                            return null;
                        }
                    }
                    if ((flags & ScopeInfo.FREE) != 0 && (flags & ScopeInfo.BOUND) == 0) {
                        code.iconst(syminf.env_index);
                        code.invokevirtual(p(PyFrame.class), "getderef",
                                sig(PyObject.class, Integer.TYPE));
                        return null;
                    }
                }
                code.ldc(name);
                code.invokevirtual(p(PyFrame.class), "getname", sig(PyObject.class, String.class));
                return null;

            case Param:
            case Store:
                loadFrame();
                if (syminf != null && (syminf.flags & ScopeInfo.GLOBAL) != 0) {
                    code.ldc(name);
                    code.aload(temporary);
                    code.invokevirtual(p(PyFrame.class), "setglobal",
                            sig(Void.TYPE, String.class, PyObject.class));
                } else {
                    if (!fast_locals) {
                        code.ldc(name);
                        code.aload(temporary);
                        code.invokevirtual(p(PyFrame.class), "setlocal",
                                sig(Void.TYPE, String.class, PyObject.class));
                    } else {
                        if (syminf == null) {
                            throw new ParseException("internal compiler error", node);
                        }
                        if ((syminf.flags & ScopeInfo.CELL) != 0) {
                            code.iconst(syminf.env_index);
                            code.aload(temporary);
                            code.invokevirtual(p(PyFrame.class), "setderef",
                                    sig(Void.TYPE, Integer.TYPE, PyObject.class));
                        } else {
                            code.iconst(syminf.locals_index);
                            code.aload(temporary);
                            code.invokevirtual(p(PyFrame.class), "setlocal",
                                    sig(Void.TYPE, Integer.TYPE, PyObject.class));
                        }
                    }
                }
                return null;
            case Del: {
                loadFrame();
                if (syminf != null && (syminf.flags & ScopeInfo.GLOBAL) != 0) {
                    code.ldc(name);
                    code.invokevirtual(p(PyFrame.class), "delglobal", sig(Void.TYPE, String.class));
                } else {
                    if (!fast_locals) {
                        code.ldc(name);
                        code.invokevirtual(p(PyFrame.class), "dellocal",
                                sig(Void.TYPE, String.class));
                    } else {
                        if (syminf == null) {
                            throw new ParseException("internal compiler error", node);
                        }
                        if ((syminf.flags & ScopeInfo.CELL) != 0) {
                            module.error("can not delete variable '" + name
                                    + "' referenced in nested scope", true, node);
                        }
                        code.iconst(syminf.locals_index);
                        code.invokevirtual(p(PyFrame.class), "dellocal",
                                sig(Void.TYPE, Integer.TYPE));
                    }
                }
                return null;
            }
        }
        return null;
    }

    @Override
    public Object visitStr(Str node) throws Exception {
        PyString s = (PyString)node.getInternalS();
        // TODO: in Python 3 there is no alteration here anymore -
        // Bytes node ought to be used for the b'' strings
        if (s instanceof PyUnicode) {
            module.unicodeConstant(s.asString()).get(code);
        } else {
            // TODO: this ought to be in Bytes visit
            module.bytesConstant(s.asString()).get(code);
        }
        return null;
    }

    private Object visitInternalGenerators(expr node, expr elt,
            java.util.List<comprehension> generators) throws Exception {
        String bound_exp = "_(x)";

        setline(node);

        code.new_(p(PyFunction.class));
        code.dup();
        loadFrame();
        code.getfield(p(PyFrame.class), "f_globals", ci(PyObject.class));

        ScopeInfo scope = module.getScopeInfo(node);

        int emptyArray = makeArray(new ArrayList<expr>());
        code.aload(emptyArray);
        scope.setup_closure();
        scope.dump();

        stmt n = new Expr(node, new Yield(node, elt));

        expr iter = null;
        for (int i = generators.size() - 1; i >= 0; i--) {
            comprehension comp = generators.get(i);
            for (int j = comp.getInternalIfs().size() - 1; j >= 0; j--) {
                java.util.List<stmt> bod = new ArrayList<stmt>();
                bod.add(n);
                n = new If(comp.getInternalIfs().get(j), comp.getInternalIfs().get(j), bod, //
                        new ArrayList<stmt>());
            }
            java.util.List<stmt> bod = new ArrayList<stmt>();
            bod.add(n);
            if (i != 0) {
                n = new For(comp, comp.getInternalTarget(), comp.getInternalIter(), bod, //
                        new ArrayList<stmt>());
            } else {
                n = new For(comp, comp.getInternalTarget(), new Name(node, bound_exp, //
                        expr_contextType.Load), bod, new ArrayList<stmt>());
                iter = comp.getInternalIter();
            }
        }

        java.util.List<stmt> bod = new ArrayList<stmt>();
        bod.add(n);
        module.codeConstant(new Suite(node, bod), "<genexpr>", true, className, false, false,
                node.getLine(), scope, cflags).get(code);

        code.aconst_null();
        if (!makeClosure(scope)) {
            code.invokespecial(p(PyFunction.class), "<init>",
                    sig(Void.TYPE, PyObject.class, PyObject[].class, PyCode.class, PyObject.class));
        } else {
            code.invokespecial(
                    p(PyFunction.class),
                    "<init>",
                    sig(Void.TYPE, PyObject.class, PyObject[].class, PyCode.class, PyObject.class,
                            PyObject[].class));
        }
        int genExp = storeTop();

        visit(iter);
        code.aload(genExp);
        code.freeLocal(genExp);
        code.swap();
        code.invokevirtual(p(PyObject.class), "__iter__", sig(PyObject.class));
        loadThreadState();
        code.swap();
        code.invokevirtual(p(PyObject.class), "__call__",
                sig(PyObject.class, ThreadState.class, PyObject.class));
        freeArray(emptyArray);

        return null;
    }

    @Override
    public Object visitGeneratorExp(GeneratorExp node) throws Exception {
        String bound_exp = "_(x)";

        setline(node);

        code.new_(p(PyFunction.class));
        code.dup();
        loadFrame();
        code.getfield(p(PyFrame.class), "f_globals", ci(PyObject.class));

        ScopeInfo scope = module.getScopeInfo(node);

        int emptyArray = makeArray(new ArrayList<expr>());
        code.aload(emptyArray);
        scope.setup_closure();
        scope.dump();

        stmt n = new Expr(node, new Yield(node, node.getInternalElt()));

        expr iter = null;
        for (int i = node.getInternalGenerators().size() - 1; i >= 0; i--) {
            comprehension comp = node.getInternalGenerators().get(i);
            for (int j = comp.getInternalIfs().size() - 1; j >= 0; j--) {
                java.util.List<stmt> bod = new ArrayList<stmt>();
                bod.add(n);
                n = new If(comp.getInternalIfs().get(j), comp.getInternalIfs().get(j), bod, //
                        new ArrayList<stmt>());
            }
            java.util.List<stmt> bod = new ArrayList<stmt>();
            bod.add(n);
            if (i != 0) {
                n = new For(comp, comp.getInternalTarget(), comp.getInternalIter(), bod, //
                        new ArrayList<stmt>());
            } else {
                n = new For(comp, comp.getInternalTarget(), new Name(node, bound_exp, //
                        expr_contextType.Load), bod, new ArrayList<stmt>());
                iter = comp.getInternalIter();
            }
        }

        java.util.List<stmt> bod = new ArrayList<stmt>();
        bod.add(n);
        module.codeConstant(new Suite(node, bod), "<genexpr>", true, className, false, false,
                node.getLine(), scope, cflags).get(code);

        code.aconst_null();
        if (!makeClosure(scope)) {
            code.invokespecial(p(PyFunction.class), "<init>",
                    sig(Void.TYPE, PyObject.class, PyObject[].class, PyCode.class, PyObject.class));
        } else {
            code.invokespecial(
                    p(PyFunction.class),
                    "<init>",
                    sig(Void.TYPE, PyObject.class, PyObject[].class, PyCode.class, PyObject.class,
                            PyObject[].class));
        }
        int genExp = storeTop();

        visit(iter);
        code.aload(genExp);
        code.freeLocal(genExp);
        code.swap();
        code.invokevirtual(p(PyObject.class), "__iter__", sig(PyObject.class));
        loadThreadState();
        code.swap();
        code.invokevirtual(p(PyObject.class), "__call__",
                sig(PyObject.class, ThreadState.class, PyObject.class));
        freeArray(emptyArray);

        return null;
    }

    @Override
    public Object visitWith(With node) throws Exception {
        if (!module.getFutures().withStatementSupported()) {
            throw new ParseException("'with' will become a reserved keyword in Python 2.6", node);
        }

        final Label label_body_start = new Label();
        final Label label_body_end = new Label();
        final Label label_catch = new Label();
        final Label label_end = new Label();

        final Method contextGuard_getManager =
                Method.getMethod("org.python.core.ContextManager getManager (org.python.core.PyObject)");
        final Method __enter__ =
                Method.getMethod("org.python.core.PyObject __enter__ (org.python.core.ThreadState)");
        final Method __exit__ =
                Method.getMethod("boolean __exit__ (org.python.core.ThreadState,org.python.core.PyException)");

        // mgr = (EXPR)
        visit(node.getInternalContext_expr());

        // wrap the manager with the ContextGuard (or get it directly if it
        // supports the ContextManager interface)
        code.invokestatic(Type.getType(ContextGuard.class).getInternalName(),
                contextGuard_getManager.getName(), contextGuard_getManager.getDescriptor());
        code.dup();

        final int mgr_tmp = code.getLocal(Type.getType(ContextManager.class).getInternalName());
        code.astore(mgr_tmp);

        // value = mgr.__enter__()
        loadThreadState();
        code.invokeinterface(Type.getType(ContextManager.class).getInternalName(),
                __enter__.getName(), __enter__.getDescriptor(), true);
        int value_tmp = code.getLocal(p(PyObject.class));
        code.astore(value_tmp);

        // exc = True # not necessary, since we don't exec finally if exception

        // FINALLY (preparation)
        // ordinarily with a finally, we need to duplicate the code. that's not the case
        // here
        // # The normal and non-local-goto cases are handled here
        // if exc: # implicit
        // exit(None, None, None)
        ExceptionHandler normalExit = new ExceptionHandler() {

            @Override
            public boolean isFinallyHandler() {
                return true;
            }

            @Override
            public void finalBody(CodeCompiler compiler) throws Exception {
                compiler.code.aload(mgr_tmp);
                loadThreadState();
                compiler.code.aconst_null();
                compiler.code.invokeinterface(Type.getType(ContextManager.class).getInternalName(),
                        __exit__.getName(), __exit__.getDescriptor(), true);
                compiler.code.pop();
            }
        };
        exceptionHandlers.push(normalExit);

        // try-catch block here
        ExceptionHandler handler = new ExceptionHandler();
        exceptionHandlers.push(handler);
        handler.exceptionStarts.addElement(label_body_start);

        // VAR = value # Only if "as VAR" is present
        code.label(label_body_start);
        if (node.getInternalOptional_vars() != null) {
            set(node.getInternalOptional_vars(), value_tmp);
        }
        code.freeLocal(value_tmp);

        // BLOCK + FINALLY if non-local-goto
        Object blockResult = suite(node.getInternalBody());
        normalExit.bodyDone = true;
        exceptionHandlers.pop();
        exceptionHandlers.pop();
        code.label(label_body_end);
        handler.exceptionEnds.addElement(label_body_end);

        // FINALLY if *not* non-local-goto
        if (blockResult == NoExit) {
            // BLOCK would have generated FINALLY for us if it exited (due to a break,
            // continue or return)
            inlineFinally(normalExit);
            code.goto_(label_end);
        }

        // CATCH
        code.label(label_catch);

        loadFrame();
        code.invokestatic(p(Py.class), "setException",
                sig(PyException.class, Throwable.class, PyFrame.class));
        code.aload(mgr_tmp);
        code.swap();
        loadThreadState();
        code.swap();
        code.invokeinterface(Type.getType(ContextManager.class).getInternalName(),
                __exit__.getName(), __exit__.getDescriptor(), true);

        // # The exceptional case is handled here
        // exc = False # implicit
        // if not exit(*sys.exc_info()):
        code.ifne(label_end);
        // raise
        // # The exception is swallowed if exit() returns true
        code.invokestatic(p(Py.class), "makeException", sig(PyException.class));
        code.checkcast(p(Throwable.class));
        code.athrow();

        code.label(label_end);
        code.freeLocal(mgr_tmp);

        handler.addExceptionHandlers(label_catch);
        return null;
    }

    @Override
    protected Object unhandled_node(PythonTree node) throws Exception {
        throw new Exception("Unhandled node " + node);
    }

    /**
     * Data about a given exception range whether a try:finally: or a try:except:. The finally needs
     * to inline the finally block for each exit of the try: section, so we carry around that data
     * for it.
     *
     * Both of these need to stop exception coverage of an area that is either the inlined fin ally
     * of a parent try:finally: or the reentry block after a yield. Thus we keep around a set of
     * exception ranges that the catch block will eventually handle.
     */
    class ExceptionHandler {

        /**
         * Each handler gets several exception ranges, this is because inlined finally exit code
         * shouldn't be covered by the exception handler of that finally block. Thus each time we
         * inline the finally code, we stop one range and then enter a new one.
         *
         * We also need to stop coverage for the recovery of the locals after a yield.
         */
        public Vector<Label> exceptionStarts = new Vector<Label>();
        public Vector<Label> exceptionEnds = new Vector<Label>();
        public boolean bodyDone = false;
        public PythonTree node = null;

        public ExceptionHandler() {}

        public ExceptionHandler(PythonTree n) {
            node = n;
        }

        public boolean isFinallyHandler() {
            return node != null;
        }

        public void addExceptionHandlers(Label handlerStart) throws Exception {
            for (int i = 0; i < exceptionStarts.size(); ++i) {
                Label start = exceptionStarts.elementAt(i);
                Label end = exceptionEnds.elementAt(i);
                // FIXME: not at all sure that getOffset() test is correct or necessary.
                if (start.getOffset() != end.getOffset()) {
                    code.trycatch(exceptionStarts.elementAt(i), exceptionEnds.elementAt(i),
                            handlerStart, p(Throwable.class));
                }
            }
        }

        public void finalBody(CodeCompiler compiler) throws Exception {
            if (node instanceof TryFinally) {
                suite(((TryFinally)node).getInternalFinalbody());
            }
        }
    }
}