1 /*
   2  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 package com.sun.tools.sjavac.comp.dependencies;
  26 
  27 import java.util.HashSet;
  28 import java.util.Set;
  29 
  30 import com.sun.tools.javac.code.Symbol;
  31 import com.sun.tools.javac.code.Symbol.ClassSymbol;
  32 import com.sun.tools.javac.code.Symbol.PackageSymbol;
  33 import com.sun.tools.javac.code.Type;
  34 import com.sun.tools.javac.code.TypeTag;
  35 import com.sun.tools.javac.tree.JCTree.JCFieldAccess;
  36 import com.sun.tools.javac.tree.JCTree.JCIdent;
  37 import com.sun.tools.javac.tree.TreeScanner;
  38 
  39 class DependencyScanner extends TreeScanner {
  40 
  41     public final Set<Dependency> dependencies = new HashSet<>();
  42 
  43     private boolean isValidDependency(Type t) {
  44         if (t == null || t.isPrimitiveOrVoid() || t.isErroneous())
  45             return false;
  46         TypeTag tag = t.getTag();
  47         return tag != TypeTag.PACKAGE
  48             && tag != TypeTag.METHOD
  49             && tag != TypeTag.ARRAY
  50             && tag != TypeTag.TYPEVAR;
  51     }
  52 
  53     @Override
  54     public void visitIdent(JCIdent tree) {
  55         if (isValidDependency(tree.type))
  56             dependencies.add(new TypeAndSupertypesDependency(tree.type.tsym));
  57         super.visitIdent(tree);
  58     }
  59 
  60     @Override
  61     public void visitSelect(JCFieldAccess tree) {
  62         if (tree.getIdentifier().contentEquals("*")) {
  63             Symbol sym = tree.selected instanceof JCIdent ? ((JCIdent) tree.selected).sym
  64                                                           : ((JCFieldAccess) tree.selected).sym;
  65             if (sym instanceof ClassSymbol) {
  66                 ClassSymbol clsSym = (ClassSymbol) sym;
  67                 dependencies.add(new TypeAndSupertypesDependency(clsSym.type.tsym));
  68             } else {
  69                 dependencies.add(new PackageDependency((PackageSymbol) sym));
  70             }
  71         } else if (tree.type != null && tree.type.hasTag(TypeTag.METHOD)) {  // Method call? Depend on the result (even though we never access it elsewhere)
  72             Type retType = tree.type.getReturnType();
  73             if (isValidDependency(retType))
  74                 dependencies.add(new TypeAndSupertypesDependency(retType.tsym));
  75         } else if (isValidDependency(tree.type)) {
  76             dependencies.add(new TypeAndSupertypesDependency(tree.type.tsym));
  77         }
  78         super.visitSelect(tree);
  79     }
  80 
  81     public Set<Dependency> getResult() {
  82         return dependencies;
  83     }
  84 }