/*
* 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.core.ext.TreeLogger;
import com.google.gwt.core.ext.UnableToCompleteException;
import com.google.gwt.dev.jjs.InternalCompilerException;
import com.google.gwt.dev.jjs.ast.Context;
import com.google.gwt.dev.jjs.ast.JDeclaredType;
import com.google.gwt.dev.jjs.ast.JMethod;
import com.google.gwt.dev.jjs.ast.JProgram;
import com.google.gwt.dev.jjs.ast.JVisitor;
import com.google.gwt.dev.jjs.ast.js.JsniMethodBody;
import com.google.gwt.dev.jjs.ast.js.JsniMethodRef;
/**
* Checks and throws errors for invalid JSNI constructs.
*/
public class JsniRestrictionChecker extends JVisitor {
public static void exec(TreeLogger logger, JProgram jprogram) throws UnableToCompleteException {
JsniRestrictionChecker jsniRestrictionChecker = new JsniRestrictionChecker(logger, jprogram);
try {
jsniRestrictionChecker.accept(jprogram);
} catch (InternalCompilerException e) {
// Already logged.
throw new UnableToCompleteException();
}
}
private JMethod currentJsniMethod;
private final JProgram jprogram;
private final TreeLogger logger;
public JsniRestrictionChecker(TreeLogger logger, JProgram jprogram) {
this.logger = logger;
this.jprogram = jprogram;
}
@Override
public boolean visit(JsniMethodBody x, Context ctx) {
currentJsniMethod = x.getMethod();
return super.visit(x, ctx);
}
@Override
public boolean visit(JsniMethodRef x, Context ctx) {
JMethod calledMethod = x.getTarget();
JDeclaredType enclosingTypeOfCalledMethod = calledMethod.getEnclosingType();
if (isNonStaticJsoClassDispatch(calledMethod, enclosingTypeOfCalledMethod)) {
logger.log(TreeLogger.ERROR, "JSNI method " + getSignature(currentJsniMethod)
+ " attempts to call non-static method " + getSignature(calledMethod)
+ " on an instance which is a subclass of JavaScriptObject. "
+ "Only static method calls on JavaScriptObject subclasses are allowed in JSNI.");
throw new UnsupportedOperationException();
} else if (isJsoInterface(enclosingTypeOfCalledMethod)) {
logger.log(TreeLogger.ERROR, "JSNI method " + getSignature(currentJsniMethod)
+ " attempts to call method " + getSignature(calledMethod)
+ " on an instance which might be a JavaScriptObject. "
+ "Such a method call is only allowed in pure Java (non-JSNI) functions.");
throw new UnsupportedOperationException();
}
return super.visit(x, ctx);
}
private String getSignature(JMethod method) {
return method.getEnclosingType().getShortName() + "." + method.getSignature();
}
private boolean isJsoInterface(JDeclaredType type) {
return jprogram.typeOracle.isSingleJsoImpl(type)
|| jprogram.typeOracle.isDualJsoInterface(type);
}
private boolean isNonStaticJsoClassDispatch(JMethod method, JDeclaredType enclosingType) {
return !method.isStatic() && jprogram.typeOracle.isJavaScriptObject(enclosingType);
}
}