/*
* Copyright 2003-2009 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.transform.sc.transformers;
import org.codehaus.groovy.ast.ClassHelper;
import org.codehaus.groovy.ast.ClassNode;
import org.codehaus.groovy.ast.MethodNode;
import org.codehaus.groovy.ast.expr.ArgumentListExpression;
import org.codehaus.groovy.ast.expr.BinaryExpression;
import org.codehaus.groovy.ast.expr.BooleanExpression;
import org.codehaus.groovy.ast.expr.ClassExpression;
import org.codehaus.groovy.ast.expr.ConstantExpression;
import org.codehaus.groovy.ast.expr.DeclarationExpression;
import org.codehaus.groovy.ast.expr.Expression;
import org.codehaus.groovy.ast.expr.ListExpression;
import org.codehaus.groovy.ast.expr.MethodCallExpression;
import org.codehaus.groovy.ast.expr.PropertyExpression;
import org.codehaus.groovy.ast.expr.TernaryExpression;
import org.codehaus.groovy.ast.expr.TupleExpression;
import org.codehaus.groovy.ast.expr.VariableExpression;
import org.codehaus.groovy.classgen.asm.sc.StaticPropertyAccessHelper;
import org.codehaus.groovy.classgen.asm.sc.StaticTypesTypeChooser;
import org.codehaus.groovy.syntax.Token;
import org.codehaus.groovy.syntax.Types;
import org.codehaus.groovy.transform.sc.ListOfExpressionsExpression;
import org.codehaus.groovy.transform.sc.TemporaryVariableExpression;
import org.codehaus.groovy.transform.stc.StaticTypeCheckingSupport;
import org.codehaus.groovy.transform.stc.StaticTypesMarker;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import static org.codehaus.groovy.transform.sc.StaticCompilationMetadataKeys.BINARY_EXP_TARGET;
public class BinaryExpressionTransformer {
private static final MethodNode COMPARE_TO_METHOD = ClassHelper.COMPARABLE_TYPE.getMethods("compareTo").get(0);
private static final ConstantExpression CONSTANT_ZERO = new ConstantExpression(0, true);
private static final ConstantExpression CONSTANT_MINUS_ONE = new ConstantExpression(-1, true);
private static final ConstantExpression CONSTANT_ONE = new ConstantExpression(1, true);
static {
CONSTANT_ZERO.setType(ClassHelper.int_TYPE);
CONSTANT_ONE.setType(ClassHelper.int_TYPE);
CONSTANT_MINUS_ONE.setType(ClassHelper.int_TYPE);
}
private int tmpVarCounter = 0;
private final StaticCompilationTransformer staticCompilationTransformer;
public BinaryExpressionTransformer(StaticCompilationTransformer staticCompilationTransformer) {
this.staticCompilationTransformer = staticCompilationTransformer;
}
Expression transformBinaryExpression(final BinaryExpression bin) {
Object[] list = (Object[]) bin.getNodeMetaData(BINARY_EXP_TARGET);
Token operation = bin.getOperation();
int operationType = operation.getType();
Expression rightExpression = bin.getRightExpression();
Expression leftExpression = bin.getLeftExpression();
if (operationType==Types.EQUAL && leftExpression instanceof PropertyExpression) {
MethodNode directMCT = leftExpression.getNodeMetaData(StaticTypesMarker.DIRECT_METHOD_CALL_TARGET);
if (directMCT!=null) {
return transformPropertyAssignmentToSetterCall((PropertyExpression) leftExpression, rightExpression, directMCT);
}
}
if (operationType==Types.COMPARE_EQUAL || operationType == Types.COMPARE_NOT_EQUAL) {
// let's check if one of the operands is the null constant
CompareToNullExpression compareToNullExpression = null;
if (isNullConstant(leftExpression)) {
compareToNullExpression = new CompareToNullExpression(staticCompilationTransformer.transform(rightExpression), operationType==Types.COMPARE_EQUAL);
} else if (isNullConstant(rightExpression)) {
compareToNullExpression = new CompareToNullExpression(staticCompilationTransformer.transform(leftExpression), operationType==Types.COMPARE_EQUAL);
}
if (compareToNullExpression != null) {
compareToNullExpression.setSourcePosition(bin);
return compareToNullExpression;
}
} else if (operationType==Types.KEYWORD_IN) {
MethodCallExpression call = new MethodCallExpression(
rightExpression,
"isCase",
leftExpression
);
call.setMethodTarget((MethodNode) bin.getNodeMetaData(StaticTypesMarker.DIRECT_METHOD_CALL_TARGET));
call.setSourcePosition(bin);
call.copyNodeMetaData(bin);
TernaryExpression tExp = new TernaryExpression(
new BooleanExpression(
new BinaryExpression(rightExpression, Token.newSymbol("==",-1,-1), new ConstantExpression(null))
),
new BinaryExpression(leftExpression, Token.newSymbol("==", -1, -1), new ConstantExpression(null)),
call
);
return staticCompilationTransformer.transform(tExp);
}
if (list != null) {
if (operationType == Types.COMPARE_TO) {
StaticTypesTypeChooser typeChooser = staticCompilationTransformer.getTypeChooser();
ClassNode classNode = staticCompilationTransformer.getClassNode();
ClassNode leftType = typeChooser.resolveType(leftExpression, classNode);
if (leftType.implementsInterface(ClassHelper.COMPARABLE_TYPE)) {
ClassNode rightType = typeChooser.resolveType(rightExpression, classNode);
if (rightType.implementsInterface(ClassHelper.COMPARABLE_TYPE)) {
Expression left = staticCompilationTransformer.transform(leftExpression);
Expression right = staticCompilationTransformer.transform(rightExpression);
MethodCallExpression call = new MethodCallExpression(left, "compareTo", new ArgumentListExpression(right));
call.setImplicitThis(false);
call.setMethodTarget(COMPARE_TO_METHOD);
CompareIdentityExpression compareIdentity = new CompareIdentityExpression(
left, right
);
compareIdentity.putNodeMetaData(StaticTypesMarker.INFERRED_RETURN_TYPE, ClassHelper.boolean_TYPE);
TernaryExpression result = new TernaryExpression(
new BooleanExpression(compareIdentity), // a==b
CONSTANT_ZERO,
new TernaryExpression(
new BooleanExpression(new CompareToNullExpression(left, true)), // a==null
CONSTANT_MINUS_ONE,
new TernaryExpression(
new BooleanExpression(new CompareToNullExpression(right, true)), // b==null
CONSTANT_ONE,
call
)
)
);
compareIdentity.putNodeMetaData(StaticTypesMarker.INFERRED_RETURN_TYPE, ClassHelper.int_TYPE);
result.putNodeMetaData(StaticTypesMarker.INFERRED_TYPE, ClassHelper.int_TYPE);
TernaryExpression expr = (TernaryExpression) result.getFalseExpression();
expr.putNodeMetaData(StaticTypesMarker.INFERRED_TYPE, ClassHelper.int_TYPE);
expr.getFalseExpression().putNodeMetaData(StaticTypesMarker.INFERRED_TYPE, ClassHelper.int_TYPE);
return result;
}
}
}
boolean isAssignment = StaticTypeCheckingSupport.isAssignment(operationType);
MethodCallExpression call;
MethodNode node = (MethodNode) list[0];
String name = (String) list[1];
Expression left = staticCompilationTransformer.transform(leftExpression);
Expression right = staticCompilationTransformer.transform(rightExpression);
call = new MethodCallExpression(
left,
name,
new ArgumentListExpression(right)
);
call.setImplicitThis(false);
call.setMethodTarget(node);
MethodNode adapter = StaticCompilationTransformer.BYTECODE_BINARY_ADAPTERS.get(operationType);
if (adapter != null) {
ClassExpression sba = new ClassExpression(StaticCompilationTransformer.BYTECODE_ADAPTER_CLASS);
// replace with compareEquals
call = new MethodCallExpression(sba,
"compareEquals",
new ArgumentListExpression(left, right));
call.setMethodTarget(adapter);
call.setImplicitThis(false);
}
if (!isAssignment) return call;
// case of +=, -=, /=, ...
// the method represents the operation type only, and we must add an assignment
return new BinaryExpression(left, Token.newSymbol("=", operation.getStartLine(), operation.getStartColumn()), call);
}
if (bin.getOperation().getType() == Types.EQUAL && leftExpression instanceof TupleExpression && rightExpression instanceof ListExpression) {
// multiple assignment
ListOfExpressionsExpression cle = new ListOfExpressionsExpression();
boolean isDeclaration = bin instanceof DeclarationExpression;
List<Expression> leftExpressions = ((TupleExpression) leftExpression).getExpressions();
List<Expression> rightExpressions = ((ListExpression) rightExpression).getExpressions();
Iterator<Expression> leftIt = leftExpressions.iterator();
Iterator<Expression> rightIt = rightExpressions.iterator();
if (isDeclaration) {
while (leftIt.hasNext()) {
Expression left = leftIt.next();
if (rightIt.hasNext()) {
Expression right = rightIt.next();
BinaryExpression bexp = new DeclarationExpression(left, bin.getOperation(), right);
bexp.setSourcePosition(right);
cle.addExpression(bexp);
}
}
} else {
// (next, result) = [ result, next+result ]
// -->
// def tmp1 = result
// def tmp2 = next+result
// next = tmp1
// result = tmp2
int size = rightExpressions.size();
List<Expression> tmpAssignments = new ArrayList<Expression>(size);
List<Expression> finalAssignments = new ArrayList<Expression>(size);
for (int i=0; i<Math.min(size, leftExpressions.size());i++ ) {
Expression left = leftIt.next();
Expression right = rightIt.next();
VariableExpression tmpVar = new VariableExpression("$tmpVar$"+tmpVarCounter++);
BinaryExpression bexp = new DeclarationExpression(tmpVar, bin.getOperation(), right);
bexp.setSourcePosition(right);
tmpAssignments.add(bexp);
bexp = new BinaryExpression(left, bin.getOperation(), new VariableExpression(tmpVar));
bexp.setSourcePosition(left);
finalAssignments.add(bexp);
}
for (Expression tmpAssignment : tmpAssignments) {
cle.addExpression(tmpAssignment);
}
for (Expression finalAssignment : finalAssignments) {
cle.addExpression(finalAssignment);
}
}
return staticCompilationTransformer.transform(cle);
}
return staticCompilationTransformer.superTransform(bin);
}
private Expression transformPropertyAssignmentToSetterCall(final PropertyExpression leftExpression, final Expression rightExpression, final MethodNode directMCT) {
// transform "a.x = b" into "def tmp = b; a.setX(tmp); tmp"
Expression arg = staticCompilationTransformer.transform(rightExpression);
return StaticPropertyAccessHelper.transformToSetterCall(
leftExpression.getObjectExpression(),
directMCT,
arg,
false,
false,
false,
true, // to be replaced with a proper test whether a return value should be used or not
leftExpression
);
}
protected static boolean isNullConstant(final Expression expression) {
return expression instanceof ConstantExpression && ((ConstantExpression) expression).getValue()==null;
}
}