1 /*

     2  * Copyright (c) 2019, 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 

    26 import com.sun.source.tree.BinaryTree;

    27 import com.sun.source.tree.ClassTree;

    28 import com.sun.source.tree.CompilationUnitTree;

    29 import com.sun.source.tree.IdentifierTree;

    30 import com.sun.source.tree.LiteralTree;

    31 import com.sun.source.tree.PrimitiveTypeTree;

    32 import com.sun.source.tree.Tree;

    33 import com.sun.source.tree.VariableTree;

    34 import com.sun.source.util.TreeScanner;

    35 

    36 import java.util.HashSet;

    37 import java.util.Locale;

    38 import java.util.Set;

    39 

    40 

    41 public class CodeBuilder {

    42 

    43     public static String buildCodeToGenerate(Tree t, String builder) {

    44         StringBuilder result = new StringBuilder();

    45         new TreeScanner<Void, Void>() {

    46             private final Set<String> usedNames = new HashSet<>();

    47             private String currentBuilder = builder;

    48             @Override

    49             public Void visitClass(ClassTree node, Void p) {

    50                 result.append(currentBuilder() + "._class(\"" + node.getSimpleName() + "\", ");

    51                 doScan("C", () -> super.visitClass(node, p));

    52                 result.append(")");

    53                 return null;

    54             }

    55             @Override

    56             public Void visitCompilationUnit(CompilationUnitTree node, Void p) {

    57                 result.append(currentBuilder() + ".createCompilationUnitTree(");

    58                 doScan("U", () -> super.visitCompilationUnit(node, p));

    59                 result.append(")");

    60                 return null;

    61             }

    62             @Override

    63             public Void visitVariable(VariableTree node, Void p) {

    64                 result.append(currentBuilder() + ".field(\"" + node.getName() + "\", "); //XXX: field/vs local variable!

    65                 doScan("T", node.getType());

    66                 result.append(", ");

    67                 doScan("F", () -> {

    68                     //TODO: modifiers....

    69                     if (node.getInitializer() != null) {

    70                         result.append(currentBuilder() + ".init(");

    71                         doScan("E", node.getInitializer());

    72                         result.append(")");

    73                     }

    74                 });

    75                 result.append(")");

    76                 return null;

    77             }

    78 

    79             @Override

    80             public Void visitPrimitiveType(PrimitiveTypeTree node, Void p) {

    81                 result.append(currentBuilder() + "._" + node.getPrimitiveTypeKind().name().toLowerCase(Locale.ROOT) + "()");

    82                 return null;

    83             }

    84 

    85             @Override

    86             public Void visitLiteral(LiteralTree node, Void p) {

    87                 result.append(currentBuilder() + ".literal(" + node.getValue() + ")");

    88                 return null;

    89             }

    90 

    91             @Override

    92             public Void visitBinary(BinaryTree node, Void p) {

    93                 switch (node.getKind()) {

    94                     case PLUS:

    95                         result.append(currentBuilder() + ".plus(");

    96                         doScan("E", node.getLeftOperand());

    97                         result.append(", ");

    98                         doScan("E", node.getRightOperand());

    99                         result.append(")");

   100                         break;

   101                     default: throw new IllegalStateException("Not handled: " + node.getKind());

   102                 }

   103                 return null;

   104             }

   105 

   106             @Override

   107             public Void visitIdentifier(IdentifierTree node, Void p) {

   108                 result.append(currentBuilder() + ".ident(\"" + node.getName() + "\")");

   109                 return null;

   110             }

   111 

   112             private String currentBuilder() {

   113                 if (currentBuilder != null) {

   114                     String res = currentBuilder;

   115                     currentBuilder = null;

   116                     return res;

   117                 }

   118                 return "";

   119             }

   120             private void doScan(String preferredBuilderName, Tree... subTreesToScan) {

   121                 doScan(preferredBuilderName, () -> {

   122                     for (Tree tree : subTreesToScan) {

   123                         scan(tree, null);

   124                     }

   125                 });

   126             }

   127 

   128             private void doScan(String preferredBuilderName, Runnable scan) {

   129                 String prevBuilder = currentBuilder;

   130                 String builder = inferBuilderName(preferredBuilderName);

   131                 try {

   132                     result.append(builder + " -> ");

   133                     int len = result.length();

   134                     currentBuilder = builder;

   135                     scan.run();

   136                     if (result.length() == len) {

   137                         result.append("{}");

   138                     }

   139                 } finally {

   140                     currentBuilder = prevBuilder;

   141                     usedNames.remove(builder);

   142                 }

   143             }

   144             private String inferBuilderName(String preferredBuilderName) {

   145                 Integer idx = null;

   146                 while (true) {

   147                     String thisBuilder = preferredBuilderName + (idx != null ? idx : "");

   148                     if (usedNames.add(thisBuilder)) {

   149                         return thisBuilder;

   150                     }

   151                     idx = idx != null ? idx + 1 : 1;

   152                 }

   153             }

   154         }.scan(t, null);

   155 

   156         return result.toString();

   157     }

   158 

   159 }