/*
* Copyright 2003-2010 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.codehaus.groovy.classgen.asm;
import java.util.Iterator;
import java.util.List;
import org.codehaus.groovy.ast.ClassHelper;
import org.codehaus.groovy.ast.ClassNode;
import org.codehaus.groovy.ast.Parameter;
import org.codehaus.groovy.ast.expr.ArgumentListExpression;
import org.codehaus.groovy.ast.expr.ClosureListExpression;
import org.codehaus.groovy.ast.expr.ConstantExpression;
import org.codehaus.groovy.ast.expr.EmptyExpression;
import org.codehaus.groovy.ast.expr.Expression;
import org.codehaus.groovy.ast.expr.MethodCallExpression;
import org.codehaus.groovy.ast.stmt.AssertStatement;
import org.codehaus.groovy.ast.stmt.BlockStatement;
import org.codehaus.groovy.ast.stmt.BreakStatement;
import org.codehaus.groovy.ast.stmt.CaseStatement;
import org.codehaus.groovy.ast.stmt.CatchStatement;
import org.codehaus.groovy.ast.stmt.ContinueStatement;
import org.codehaus.groovy.ast.stmt.DoWhileStatement;
import org.codehaus.groovy.ast.stmt.EmptyStatement;
import org.codehaus.groovy.ast.stmt.ExpressionStatement;
import org.codehaus.groovy.ast.stmt.ForStatement;
import org.codehaus.groovy.ast.stmt.IfStatement;
import org.codehaus.groovy.ast.stmt.ReturnStatement;
import org.codehaus.groovy.ast.stmt.Statement;
import org.codehaus.groovy.ast.stmt.SwitchStatement;
import org.codehaus.groovy.ast.stmt.SynchronizedStatement;
import org.codehaus.groovy.ast.stmt.ThrowStatement;
import org.codehaus.groovy.ast.stmt.TryCatchStatement;
import org.codehaus.groovy.ast.stmt.WhileStatement;
import org.codehaus.groovy.classgen.asm.CompileStack.BlockRecorder;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import static org.objectweb.asm.Opcodes.*;
public class StatementWriter {
// iterator
private static final MethodCaller iteratorNextMethod = MethodCaller.newInterface(Iterator.class, "next");
private static final MethodCaller iteratorHasNextMethod = MethodCaller.newInterface(Iterator.class, "hasNext");
private WriterController controller;
public StatementWriter(WriterController controller) {
this.controller = controller;
}
protected void writeStatementLabel(Statement statement) {
String name = statement.getStatementLabel();
if (name != null) {
Label label = controller.getCompileStack().createLocalLabel(name);
controller.getMethodVisitor().visitLabel(label);
}
}
public void writeBlockStatement(BlockStatement block) {
CompileStack compileStack = controller.getCompileStack();
//GROOVY-4505 use no line number information for the block
writeStatementLabel(block);
int mark = controller.getOperandStack().getStackLength();
compileStack.pushVariableScope(block.getVariableScope());
for (Statement statement : block.getStatements()) {
statement.visit(controller.getAcg());
}
compileStack.pop();
controller.getOperandStack().popDownTo(mark);
}
public void writeForStatement(ForStatement loop) {
Parameter loopVar = loop.getVariable();
if (loopVar == ForStatement.FOR_LOOP_DUMMY) {
writeForLoopWithClosureList(loop);
} else {
writeForInLoop(loop);
}
}
protected void writeIteratorHasNext(MethodVisitor mv) {
iteratorHasNextMethod.call(mv);
}
protected void writeIteratorNext(MethodVisitor mv) {
iteratorNextMethod.call(mv);
}
protected void writeForInLoop(ForStatement loop) {
controller.getAcg().onLineNumber(loop,"visitForLoop");
writeStatementLabel(loop);
CompileStack compileStack = controller.getCompileStack();
MethodVisitor mv = controller.getMethodVisitor();
OperandStack operandStack = controller.getOperandStack();
compileStack.pushLoop(loop.getVariableScope(), loop.getStatementLabels());
// Declare the loop counter.
BytecodeVariable variable = compileStack.defineVariable(loop.getVariable(), false);
// Then get the iterator and generate the loop control
MethodCallExpression iterator = new MethodCallExpression(loop.getCollectionExpression(), "iterator", new ArgumentListExpression());
iterator.visit(controller.getAcg());
operandStack.doGroovyCast(ClassHelper.Iterator_TYPE);
final int iteratorIdx = compileStack.defineTemporaryVariable("iterator", ClassHelper.Iterator_TYPE, true);
Label continueLabel = compileStack.getContinueLabel();
Label breakLabel = compileStack.getBreakLabel();
mv.visitLabel(continueLabel);
mv.visitVarInsn(ALOAD, iteratorIdx);
writeIteratorHasNext(mv);
// note: ifeq tests for ==0, a boolean is 0 if it is false
mv.visitJumpInsn(IFEQ, breakLabel);
mv.visitVarInsn(ALOAD, iteratorIdx);
writeIteratorNext(mv);
operandStack.push(ClassHelper.OBJECT_TYPE);
operandStack.storeVar(variable);
// Generate the loop body
loop.getLoopBlock().visit(controller.getAcg());
mv.visitJumpInsn(GOTO, continueLabel);
mv.visitLabel(breakLabel);
compileStack.pop();
}
protected void writeForLoopWithClosureList(ForStatement loop) {
controller.getAcg().onLineNumber(loop,"visitForLoop");
writeStatementLabel(loop);
MethodVisitor mv = controller.getMethodVisitor();
controller.getCompileStack().pushLoop(loop.getVariableScope(), loop.getStatementLabels());
ClosureListExpression clExpr = (ClosureListExpression) loop.getCollectionExpression();
controller.getCompileStack().pushVariableScope(clExpr.getVariableScope());
List expressions = clExpr.getExpressions();
int size = expressions.size();
// middle element is condition, lower half is init, higher half is increment
int condIndex = (size - 1) / 2;
// visit init
for (int i = 0; i < condIndex; i++) {
visitExpressionOrStatement(expressions.get(i));
}
Label continueLabel = controller.getCompileStack().getContinueLabel();
Label breakLabel = controller.getCompileStack().getBreakLabel();
Label cond = new Label();
mv.visitLabel(cond);
// visit condition leave boolean on stack
{
Expression condExpr = (Expression) expressions.get(condIndex);
int mark = controller.getOperandStack().getStackLength();
condExpr.visit(controller.getAcg());
controller.getOperandStack().castToBool(mark,true);
}
// jump if we don't want to continue
// note: ifeq tests for ==0, a boolean is 0 if it is false
controller.getOperandStack().jump(IFEQ, breakLabel);
// Generate the loop body
loop.getLoopBlock().visit(controller.getAcg());
// visit increment
mv.visitLabel(continueLabel);
for (int i = condIndex + 1; i < size; i++) {
visitExpressionOrStatement(expressions.get(i));
}
// jump to test the condition again
mv.visitJumpInsn(GOTO, cond);
// loop end
mv.visitLabel(breakLabel);
controller.getCompileStack().pop();
controller.getCompileStack().pop();
}
private void visitExpressionOrStatement(Object o) {
if (o == EmptyExpression.INSTANCE) return;
if (o instanceof Expression) {
Expression expr = (Expression) o;
int mark = controller.getOperandStack().getStackLength();
expr.visit(controller.getAcg());
controller.getOperandStack().popDownTo(mark);
} else {
((Statement) o).visit(controller.getAcg());
}
}
public void writeWhileLoop(WhileStatement loop) {
controller.getAcg().onLineNumber(loop,"visitWhileLoop");
writeStatementLabel(loop);
MethodVisitor mv = controller.getMethodVisitor();
controller.getCompileStack().pushLoop(loop.getStatementLabels());
Label continueLabel = controller.getCompileStack().getContinueLabel();
Label breakLabel = controller.getCompileStack().getBreakLabel();
mv.visitLabel(continueLabel);
Expression bool = loop.getBooleanExpression();
boolean boolHandled = false;
if (bool instanceof ConstantExpression) {
ConstantExpression constant = (ConstantExpression) bool;
if (constant.getValue()==Boolean.TRUE) {
boolHandled = true;
// do nothing
} else if (constant.getValue()==Boolean.FALSE) {
boolHandled = true;
mv.visitJumpInsn(GOTO, breakLabel);
}
}
if(!boolHandled) {
bool.visit(controller.getAcg());
controller.getOperandStack().jump(IFEQ, breakLabel);
}
loop.getLoopBlock().visit(controller.getAcg());
mv.visitJumpInsn(GOTO, continueLabel);
mv.visitLabel(breakLabel);
controller.getCompileStack().pop();
}
public void writeDoWhileLoop(DoWhileStatement loop) {
controller.getAcg().onLineNumber(loop,"visitDoWhileLoop");
writeStatementLabel(loop);
MethodVisitor mv = controller.getMethodVisitor();
controller.getCompileStack().pushLoop(loop.getStatementLabels());
Label breakLabel = controller.getCompileStack().getBreakLabel();
Label continueLabel = controller.getCompileStack().getContinueLabel();
mv.visitLabel(continueLabel);
loop.getLoopBlock().visit(controller.getAcg());
loop.getBooleanExpression().visit(controller.getAcg());
controller.getOperandStack().jump(IFEQ, continueLabel);
mv.visitLabel(breakLabel);
controller.getCompileStack().pop();
}
public void writeIfElse(IfStatement ifElse) {
controller.getAcg().onLineNumber(ifElse,"visitIfElse");
writeStatementLabel(ifElse);
MethodVisitor mv = controller.getMethodVisitor();
ifElse.getBooleanExpression().visit(controller.getAcg());
Label l0 = controller.getOperandStack().jump(IFEQ);
// if-else is here handled as a special version
// of a boolean expression
controller.getCompileStack().pushBooleanExpression();
ifElse.getIfBlock().visit(controller.getAcg());
controller.getCompileStack().pop();
if (ifElse.getElseBlock()==EmptyStatement.INSTANCE) {
mv.visitLabel(l0);
} else {
Label l1 = new Label();
mv.visitJumpInsn(GOTO, l1);
mv.visitLabel(l0);
controller.getCompileStack().pushBooleanExpression();
ifElse.getElseBlock().visit(controller.getAcg());
controller.getCompileStack().pop();
mv.visitLabel(l1);
}
}
public void writeTryCatchFinally(TryCatchStatement statement) {
controller.getAcg().onLineNumber(statement, "visitTryCatchFinally");
writeStatementLabel(statement);
MethodVisitor mv = controller.getMethodVisitor();
CompileStack compileStack = controller.getCompileStack();
OperandStack operandStack = controller.getOperandStack();
Statement tryStatement = statement.getTryStatement();
final Statement finallyStatement = statement.getFinallyStatement();
// start try block, label needed for exception table
Label tryStart = new Label();
mv.visitLabel(tryStart);
BlockRecorder tryBlock = makeBlockRecorder(finallyStatement);
tryBlock.startRange(tryStart);
tryStatement.visit(controller.getAcg());
// goto finally part
Label finallyStart = new Label();
mv.visitJumpInsn(GOTO, finallyStart);
Label tryEnd = new Label();
mv.visitLabel(tryEnd);
tryBlock.closeRange(tryEnd);
// pop for "makeBlockRecorder(finallyStatement)"
controller.getCompileStack().pop();
BlockRecorder catches = makeBlockRecorder(finallyStatement);
for (CatchStatement catchStatement : statement.getCatchStatements()) {
ClassNode exceptionType = catchStatement.getExceptionType();
String exceptionTypeInternalName = BytecodeHelper.getClassInternalName(exceptionType);
// start catch block, label needed for exception table
Label catchStart = new Label();
mv.visitLabel(catchStart);
catches.startRange(catchStart);
// create exception variable and store the exception
Parameter exceptionVariable = catchStatement.getVariable();
compileStack.pushState();
compileStack.defineVariable(exceptionVariable, true);
// handle catch body
catchStatement.visit(controller.getAcg());
// place holder to avoid problems with empty catch blocks
mv.visitInsn(NOP);
// pop for the variable
controller.getCompileStack().pop();
// end of catch
Label catchEnd = new Label();
mv.visitLabel(catchEnd);
catches.closeRange(catchEnd);
// goto finally start
mv.visitJumpInsn(GOTO, finallyStart);
compileStack.writeExceptionTable(tryBlock, catchStart, exceptionTypeInternalName);
}
// Label used to handle exceptions in catches and regularly
// visited finals.
Label catchAny = new Label();
// add "catch any" block to exception table for try part we do this
// after the exception blocks, because else this one would supersede
// any of those otherwise
compileStack.writeExceptionTable(tryBlock, catchAny, null);
// same for the catch parts
compileStack.writeExceptionTable(catches, catchAny, null);
// pop for "makeBlockRecorder(catches)"
compileStack.pop();
// start finally
mv.visitLabel(finallyStart);
finallyStatement.visit(controller.getAcg());
mv.visitInsn(NOP); //**
// goto after all-catching block
Label skipCatchAll = new Label();
mv.visitJumpInsn(GOTO, skipCatchAll);
// start a block catching any Exception
mv.visitLabel(catchAny);
//store exception
//TODO: maybe define a Throwable and use it here instead of Object
operandStack.push(ClassHelper.OBJECT_TYPE);
int anyExceptionIndex = compileStack.defineTemporaryVariable("exception", true);
finallyStatement.visit(controller.getAcg());
// load the exception and rethrow it
mv.visitVarInsn(ALOAD, anyExceptionIndex);
mv.visitInsn(ATHROW);
mv.visitLabel(skipCatchAll);
}
private BlockRecorder makeBlockRecorder(final Statement finallyStatement) {
final BlockRecorder block = new BlockRecorder();
Runnable tryRunner = new Runnable() {
public void run() {
controller.getCompileStack().pushBlockRecorderVisit(block);
finallyStatement.visit(controller.getAcg());
controller.getCompileStack().popBlockRecorderVisit(block);
}
};
block.excludedStatement = tryRunner;
controller.getCompileStack().pushBlockRecorder(block);
return block;
}
public void writeSwitch(SwitchStatement statement) {
controller.getAcg().onLineNumber(statement, "visitSwitch");
writeStatementLabel(statement);
statement.getExpression().visit(controller.getAcg());
// switch does not have a continue label. use its parent's for continue
Label breakLabel = controller.getCompileStack().pushSwitch();
int switchVariableIndex = controller.getCompileStack().defineTemporaryVariable("switch", true);
List caseStatements = statement.getCaseStatements();
int caseCount = caseStatements.size();
Label[] labels = new Label[caseCount + 1];
for (int i = 0; i < caseCount; i++) {
labels[i] = new Label();
}
int i = 0;
for (Iterator iter = caseStatements.iterator(); iter.hasNext(); i++) {
CaseStatement caseStatement = (CaseStatement) iter.next();
writeCaseStatement(caseStatement, switchVariableIndex, labels[i], labels[i + 1]);
}
statement.getDefaultStatement().visit(controller.getAcg());
controller.getMethodVisitor().visitLabel(breakLabel);
controller.getCompileStack().pop();
}
protected void writeCaseStatement(
CaseStatement statement, int switchVariableIndex,
Label thisLabel, Label nextLabel)
{
controller.getAcg().onLineNumber(statement, "visitCaseStatement");
MethodVisitor mv = controller.getMethodVisitor();
OperandStack operandStack = controller.getOperandStack();
mv.visitVarInsn(ALOAD, switchVariableIndex);
statement.getExpression().visit(controller.getAcg());
operandStack.box();
controller.getBinaryExpressionHelper().getIsCaseMethod().call(mv);
operandStack.replace(ClassHelper.boolean_TYPE);
Label l0 = controller.getOperandStack().jump(IFEQ);
mv.visitLabel(thisLabel);
statement.getCode().visit(controller.getAcg());
// now if we don't finish with a break we need to jump past
// the next comparison
if (nextLabel != null) {
mv.visitJumpInsn(GOTO, nextLabel);
}
mv.visitLabel(l0);
}
public void writeBreak(BreakStatement statement) {
controller.getAcg().onLineNumber(statement, "visitBreakStatement");
writeStatementLabel(statement);
String name = statement.getLabel();
Label breakLabel = controller.getCompileStack().getNamedBreakLabel(name);
controller.getCompileStack().applyFinallyBlocks(breakLabel, true);
controller.getMethodVisitor().visitJumpInsn(GOTO, breakLabel);
}
public void writeContinue(ContinueStatement statement) {
controller.getAcg().onLineNumber(statement, "visitContinueStatement");
writeStatementLabel(statement);
String name = statement.getLabel();
Label continueLabel = controller.getCompileStack().getContinueLabel();
if (name != null) continueLabel = controller.getCompileStack().getNamedContinueLabel(name);
controller.getCompileStack().applyFinallyBlocks(continueLabel, false);
controller.getMethodVisitor().visitJumpInsn(GOTO, continueLabel);
}
public void writeSynchronized(SynchronizedStatement statement) {
controller.getAcg().onLineNumber(statement, "visitSynchronizedStatement");
writeStatementLabel(statement);
final MethodVisitor mv = controller.getMethodVisitor();
CompileStack compileStack = controller.getCompileStack();
statement.getExpression().visit(controller.getAcg());
controller.getOperandStack().box();
final int index = compileStack.defineTemporaryVariable("synchronized", ClassHelper.OBJECT_TYPE, true);
final Label synchronizedStart = new Label();
final Label synchronizedEnd = new Label();
final Label catchAll = new Label();
mv.visitVarInsn(ALOAD, index);
mv.visitInsn(MONITORENTER);
mv.visitLabel(synchronizedStart);
// place holder for "empty" synchronized blocks, for example
// if there is only a break/continue.
mv.visitInsn(NOP);
Runnable finallyPart = new Runnable() {
public void run() {
mv.visitVarInsn(ALOAD, index);
mv.visitInsn(MONITOREXIT);
}
};
BlockRecorder fb = new BlockRecorder(finallyPart);
fb.startRange(synchronizedStart);
compileStack.pushBlockRecorder(fb);
statement.getCode().visit(controller.getAcg());
fb.closeRange(catchAll);
compileStack.writeExceptionTable(fb, catchAll, null);
compileStack.pop(); //pop fb
finallyPart.run();
mv.visitJumpInsn(GOTO, synchronizedEnd);
mv.visitLabel(catchAll);
finallyPart.run();
mv.visitInsn(ATHROW);
mv.visitLabel(synchronizedEnd);
}
public void writeAssert(AssertStatement statement) {
controller.getAcg().onLineNumber(statement, "visitAssertStatement");
writeStatementLabel(statement);
controller.getAssertionWriter().writeAssertStatement(statement);
}
public void writeThrow(ThrowStatement statement) {
controller.getAcg().onLineNumber(statement, "visitThrowStatement");
writeStatementLabel(statement);
MethodVisitor mv = controller.getMethodVisitor();
statement.getExpression().visit(controller.getAcg());
// we should infer the type of the exception from the expression
mv.visitTypeInsn(CHECKCAST, "java/lang/Throwable");
mv.visitInsn(ATHROW);
controller.getOperandStack().remove(1);
}
public void writeReturn(ReturnStatement statement) {
controller.getAcg().onLineNumber(statement, "visitReturnStatement");
writeStatementLabel(statement);
MethodVisitor mv = controller.getMethodVisitor();
OperandStack operandStack = controller.getOperandStack();
ClassNode returnType = controller.getReturnType();
if (returnType == ClassHelper.VOID_TYPE) {
if (!(statement.isReturningNullOrVoid())) {
//TODO: move to Verifier
controller.getAcg().throwException("Cannot use return statement with an expression on a method that returns void");
}
controller.getCompileStack().applyBlockRecorder();
mv.visitInsn(RETURN);
return;
}
Expression expression = statement.getExpression();
expression.visit(controller.getAcg());
operandStack.doGroovyCast(returnType);
if (controller.getCompileStack().hasBlockRecorder()) {
ClassNode type = operandStack.getTopOperand();
int returnValueIdx = controller.getCompileStack().defineTemporaryVariable("returnValue", returnType, true);
controller.getCompileStack().applyBlockRecorder();
operandStack.load(type, returnValueIdx);
}
BytecodeHelper.doReturn(mv, returnType);
operandStack.remove(1);
}
public void writeExpressionStatement(ExpressionStatement statement) {
controller.getAcg().onLineNumber(statement, "visitExpressionStatement: " + statement.getExpression().getClass().getName());
writeStatementLabel(statement);
Expression expression = statement.getExpression();
int mark = controller.getOperandStack().getStackLength();
expression.visit(controller.getAcg());
controller.getOperandStack().popDownTo(mark);
}
}