/*
* Copyright 2012 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.js;
import com.google.gwt.dev.jjs.SourceInfo;
import com.google.gwt.dev.js.ast.JsBinaryOperation;
import com.google.gwt.dev.js.ast.JsBinaryOperator;
import com.google.gwt.dev.js.ast.JsContext;
import com.google.gwt.dev.js.ast.JsExpression;
import com.google.gwt.dev.js.ast.JsFunction;
import com.google.gwt.dev.js.ast.JsInvocation;
import com.google.gwt.dev.js.ast.JsModVisitor;
import com.google.gwt.dev.js.ast.JsNameRef;
import com.google.gwt.dev.js.ast.JsNumberLiteral;
import com.google.gwt.dev.js.ast.JsObjectLiteral;
import com.google.gwt.dev.js.ast.JsProgram;
import com.google.gwt.dev.js.ast.JsPropertyInitializer;
import com.google.gwt.dev.js.ast.JsStringLiteral;
import com.google.gwt.thirdparty.guava.common.annotations.VisibleForTesting;
import com.google.gwt.thirdparty.guava.common.collect.Multimap;
import java.util.List;
/**
* Instruments the generated JavaScript to record code coverage information
* about the original Java source.
*
* We maintain a global coverage object, whose keys are Java source filenames
* and whose values are objects mapping line numbers to 1 (executed) or 0 (not
* executed).
*/
public class CoverageInstrumentor {
/**
* This class does the actual instrumentation. It replaces
* {@code expr} with {@code (CoverageUtil.cover(file, line), expr)}.
*/
private class Instrumentor extends CoverageVisitor {
public Instrumentor() {
super(instrumentableLines.keySet());
}
@Override
public void endVisit(JsExpression x, JsContext ctx) {
SourceInfo info = x.getSourceInfo();
if (!instrumentableLines.containsEntry(info.getFileName(), info.getStartLine())) {
return;
}
JsInvocation update = new JsInvocation(info,
jsProgram.getIndexedFunction("CoverageUtil.cover"),
new JsStringLiteral(info, info.getFileName()),
new JsNumberLiteral(info, info.getStartLine()));
ctx.replaceMe(new JsBinaryOperation(info, JsBinaryOperator.COMMA, update, x));
}
}
public static void exec(JsProgram jsProgram, Multimap<String, Integer> instrumentableLines) {
new CoverageInstrumentor(jsProgram, instrumentableLines).execImpl();
}
/**
* Creates the baseline coverage object, with an entry mapping to 0 for every
* instrumented line.
*/
@VisibleForTesting
static JsObjectLiteral baselineCoverage(SourceInfo info,
Multimap<String, Integer> instrumentableLines) {
JsObjectLiteral baseline = new JsObjectLiteral(info);
List<JsPropertyInitializer> properties = baseline.getPropertyInitializers();
for (String filename : instrumentableLines.keySet()) {
JsPropertyInitializer pair = new JsPropertyInitializer(info);
pair.setLabelExpr(new JsStringLiteral(info, filename));
JsObjectLiteral lines = new JsObjectLiteral(info);
List<JsPropertyInitializer> coverage = lines.getPropertyInitializers();
for (int line : instrumentableLines.get(filename)) {
coverage.add(new JsPropertyInitializer(info,
new JsNumberLiteral(info, line), new JsNumberLiteral(info, 0)));
}
pair.setValueExpr(lines);
properties.add(pair);
}
return baseline;
}
private Multimap<String, Integer> instrumentableLines;
private JsProgram jsProgram;
private CoverageInstrumentor(JsProgram jsProgram, Multimap<String, Integer> instrumentableLines) {
this.instrumentableLines = instrumentableLines;
this.jsProgram = jsProgram;
}
private void addBeforeUnloadListener(SourceInfo info) {
JsNameRef onbeforeunload = new JsNameRef(info, "onbeforeunload");
onbeforeunload.setQualifier(new JsNameRef(info, "window"));
JsNameRef handler =
jsProgram.getIndexedFunction("CoverageUtil.onBeforeUnload").getName().makeRef(info);
JsBinaryOperation assignment = new JsBinaryOperation(info, JsBinaryOperator.ASG,
onbeforeunload, handler);
jsProgram.getGlobalBlock().getStatements().add(assignment.makeStmt());
}
private void execImpl() {
SourceInfo info = jsProgram.createSourceInfoSynthetic(getClass());
addBeforeUnloadListener(info);
initializeBaselineCoverage(info);
new JsModVisitor() {
@Override
public void endVisit(JsFunction x, JsContext ctx) {
new Instrumentor().accept(x.getBody());
}
}.accept(jsProgram);
}
private void initializeBaselineCoverage(SourceInfo info) {
JsNameRef coverageObject = jsProgram.getIndexedField("CoverageUtil.coverage").makeRef(info);
JsBinaryOperation init = new JsBinaryOperation(info, JsBinaryOperator.ASG, coverageObject,
baselineCoverage(info, instrumentableLines));
jsProgram.getGlobalBlock().getStatements().add(init.makeStmt());
}
}