/*
* Copyright 2014 Google Inc.
*
* 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 com.google.gwt.dev.jjs.impl;
import com.google.gwt.dev.jjs.SourceInfo;
import com.google.gwt.dev.jjs.SourceOrigin;
import com.google.gwt.dev.jjs.ast.JBooleanLiteral;
import com.google.gwt.dev.jjs.ast.JCharLiteral;
import com.google.gwt.dev.jjs.ast.JDoubleLiteral;
import com.google.gwt.dev.jjs.ast.JExpression;
import com.google.gwt.dev.jjs.ast.JFloatLiteral;
import com.google.gwt.dev.jjs.ast.JIntLiteral;
import com.google.gwt.dev.jjs.ast.JLiteral;
import com.google.gwt.dev.jjs.ast.JLongLiteral;
import com.google.gwt.dev.jjs.ast.JNullLiteral;
import com.google.gwt.dev.jjs.ast.JStringLiteral;
import com.google.gwt.dev.jjs.ast.js.JMultiExpression;
import com.google.gwt.dev.js.ast.JsBooleanLiteral;
import com.google.gwt.dev.js.ast.JsExpression;
import com.google.gwt.dev.js.ast.JsLiteral;
import com.google.gwt.dev.js.ast.JsName;
import com.google.gwt.dev.js.ast.JsNullLiteral;
import com.google.gwt.dev.js.ast.JsNumberLiteral;
import com.google.gwt.dev.js.ast.JsObjectLiteral;
import com.google.gwt.dev.js.ast.JsStringLiteral;
import com.google.gwt.lang.LongLib;
import com.google.gwt.thirdparty.guava.common.base.Predicate;
import com.google.gwt.thirdparty.guava.common.base.Predicates;
import com.google.gwt.thirdparty.guava.common.collect.Collections2;
import com.google.gwt.thirdparty.guava.common.collect.ImmutableMap;
import com.google.gwt.thirdparty.guava.common.collect.Lists;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
/**
* General utilities related to Java AST manipulation.
*/
public class JjsUtils {
/**
* Creates a multi expression from a list of expressions, removing expressions that do
* not have side effects if possible.
*/
public static JExpression createOptimizedMultiExpression(JExpression... expressions) {
return createOptimizedMultiExpression(false, Arrays.asList(expressions));
}
/**
* Creates a multi expression from a list of expressions, removing expressions that do
* not have side effects if possible.
*/
public static JExpression createOptimizedMultiExpression(boolean ignoringResult,
List<JExpression> expressions) {
int numberOfExpressions = expressions.size();
JExpression result = expressions.get(numberOfExpressions - 1);
numberOfExpressions = expressions.size();
if (numberOfExpressions == 0) {
return new JMultiExpression(SourceOrigin.UNKNOWN);
}
expressions = Lists.newArrayList(Collections2.filter(
expressions.subList(0, numberOfExpressions - 1),
Predicates.and(
Predicates.notNull(),
new Predicate<JExpression>() {
@Override
public boolean apply(JExpression expression) {
return expression.hasSideEffects();
}
})));
if (result != null && (!ignoringResult || result.hasSideEffects())) {
expressions.add(result);
}
if (expressions.size() == 1) {
// Do not create a multi expression if it consists only of the result.
return expressions.iterator().next();
}
SourceInfo info = expressions.size() > 0 ? expressions.get(0).getSourceInfo() :
SourceOrigin.UNKNOWN;
return new JMultiExpression(info, expressions);
}
/**
* Translates a Java literal into a JavaScript literal.
*/
public static JsLiteral translateLiteral(JLiteral literal) {
return translatorByLiteralClass.get(literal.getClass()).translate(literal);
}
private static Map<Class<? extends JLiteral>, LiteralTranslators> translatorByLiteralClass =
new ImmutableMap.Builder()
.put(JBooleanLiteral.class, LiteralTranslators.BOOLEAN_LITERAL_TRANSLATOR)
.put(JCharLiteral.class, LiteralTranslators.CHAR_LITERAL_TRANSLATOR)
.put(JFloatLiteral.class, LiteralTranslators.FLOAT_LITERAL_TRANSLATOR)
.put(JDoubleLiteral.class, LiteralTranslators.DOUBLE_LITERAL_TRANSLATOR)
.put(JIntLiteral.class, LiteralTranslators.INT_LITERAL_TRANSLATOR)
.put(JLongLiteral.class, LiteralTranslators.LONG_LITERAL_TRANSLATOR)
.put(JNullLiteral.class, LiteralTranslators.NULL_LITERAL_TRANSLATOR)
.put(JStringLiteral.class, LiteralTranslators.STRING_LITERAL_TRANSLATOR)
.build();
private enum LiteralTranslators {
BOOLEAN_LITERAL_TRANSLATOR() {
@Override
JsLiteral translate(JExpression literal) {
return JsBooleanLiteral.get(((JBooleanLiteral) literal).getValue());
}
},
CHAR_LITERAL_TRANSLATOR() {
@Override
JsLiteral translate(JExpression literal) {
return new JsNumberLiteral(literal.getSourceInfo(), ((JCharLiteral) literal).getValue());
}
},
FLOAT_LITERAL_TRANSLATOR() {
@Override
JsLiteral translate(JExpression literal) {
return new JsNumberLiteral(literal.getSourceInfo(), ((JFloatLiteral) literal).getValue());
}
},
DOUBLE_LITERAL_TRANSLATOR() {
@Override
JsLiteral translate(JExpression literal) {
return new JsNumberLiteral(literal.getSourceInfo(), ((JDoubleLiteral) literal).getValue());
}
},
INT_LITERAL_TRANSLATOR() {
@Override
JsLiteral translate(JExpression literal) {
return new JsNumberLiteral(literal.getSourceInfo(), ((JIntLiteral) literal).getValue());
}
},
LONG_LITERAL_TRANSLATOR() {
@Override
JsLiteral translate(JExpression literal) {
SourceInfo sourceInfo = literal.getSourceInfo();
int[] values = LongLib.getAsIntArray(((JLongLiteral) literal).getValue());
JsObjectLiteral objectLiteral = new JsObjectLiteral(sourceInfo);
objectLiteral.setInternable();
assert values.length == names.length;
for (int i = 0; i < names.length; i++) {
addPropertyToObject(sourceInfo, names[i], values[i], objectLiteral);
}
return objectLiteral;
}
},
STRING_LITERAL_TRANSLATOR() {
@Override
JsLiteral translate(JExpression literal) {
return new JsStringLiteral(literal.getSourceInfo(), ((JStringLiteral) literal).getValue());
}
},
NULL_LITERAL_TRANSLATOR() {
@Override
JsLiteral translate(JExpression literal) {
return JsNullLiteral.INSTANCE;
}
};
private static final JsName[] names;
static {
// The names of the components in an emulated long ('l', 'm', and 'h') are accessed directly
// through JSNI in LongLib (the implementor of emulated long operations), hence it is
// important that they don't get renamed hence the corresponding JsNames are created
// unscoped (null scope) and unobfuscatable.
String[] stringNames = {"l","m","h"};
names = new JsName[stringNames.length];
for (int i = 0; i < stringNames.length; i++) {
names[i] = new JsName(null, stringNames[i], stringNames[i]);
names[i].setObfuscatable(false);
}
}
abstract JsLiteral translate(JExpression literal);
}
private static void addPropertyToObject(SourceInfo sourceInfo, JsName propertyName,
int propertyValue, JsObjectLiteral objectLiteral) {
JsExpression label = propertyName.makeRef(sourceInfo);
JsExpression value = new JsNumberLiteral(sourceInfo, propertyValue);
objectLiteral.addProperty(sourceInfo, label, value);
}
private JjsUtils() {
}
}