1 /*
2 * Copyright (c) 2018, 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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23 package com.sun.tools.jextract;
24
25 import java.nio.file.Path;
26 import java.nio.file.Paths;
27 import java.util.ArrayList;
28 import java.util.Arrays;
29 import java.util.HashMap;
30 import java.util.List;
31 import java.util.Map;
32 import java.util.Optional;
33 import java.util.stream.Collectors;
34 import com.sun.tools.jextract.parser.Parser;
35 import com.sun.tools.jextract.tree.EnumTree;
36 import com.sun.tools.jextract.tree.HeaderTree;
37 import com.sun.tools.jextract.tree.SimpleTreeVisitor;
38 import com.sun.tools.jextract.tree.StructTree;
39 import com.sun.tools.jextract.tree.Tree;
40 import com.sun.tools.jextract.tree.TreeMaker;
41 import com.sun.tools.jextract.tree.TreePhase;
42 import com.sun.tools.jextract.tree.TreePrinter;
43 import com.sun.tools.jextract.tree.TypedefTree;
44 import jdk.internal.clang.Cursor;
45
46 /**
47 * This visitor handles certain typedef declarations.
48 *
49 * 1. Remove redundant typedefs.
50 * 2. Rename typedef'ed anonymous type definitions like
51 * typedef struct { int x; int y; } Point;
52 * 3. Remove redundant struct/union/enum forward/backward declarations
53 */
54 final class TypedefHandler extends SimpleTreeVisitor<Void, Void>
55 implements TreePhase {
56 private final TreeMaker treeMaker = new TreeMaker();
57
58 // Potential Tree instances that will go into transformed HeaderTree
59 // are collected in this list.
60 private final List<Tree> decls = new ArrayList<>();
61
62 // Tree instances that are to be replaced from "decls" list are
63 // saved in the following Map.
64 private final Map<Cursor, Tree> replacements = new HashMap<>();
65
66 @Override
67 public HeaderTree transform(HeaderTree ht) {
68 // Process all header declarations are collect potential
69 // declarations that will go into transformed HeaderTree
70 // into the this.decls field.
71 ht.accept(this, null);
72
73 // Replace trees from this.decls with Trees found in this.replacements.
74 // We need this two step process so that named StructTree instances
75 // will replace with original unnamed StructTree instances.
76 List<Tree> newDecls = decls.stream().map(tx -> {
77 if (replacements.containsKey(tx.cursor())) {
78 return replacements.get(tx.cursor());
79 } else {
80 return tx;
81 }
82 }).collect(Collectors.toList());
83
84 return treeMaker.createHeader(ht.cursor(), ht.path(), newDecls);
85 }
86
87 @Override
88 public Void defaultAction(Tree tree, Void v) {
89 decls.add(tree);
90 return null;
91 }
92
93 @Override
94 public Void visitEnum(EnumTree e, Void v) {
95 /*
96 * If we're seeing a forward/backward declaration of an
97 * enum which is definied elsewhere in this compilation
98 * unit, ignore it. If no definition is found, we want to
99 * leave the declaration so that dummy definition will be
100 * generated.
101 *
102 * Example:
103 *
104 * enum Color ; // <-- forward declaration
105 * struct Point { int i; int j; };
106 * struct Point3D { int i; int j; int k; };
107 * struct Point3D; // <-- backward declaration
108 */
109
110 // include this only if this is a definition or a declaration
111 // for which no definition is found elsewhere.
112 if (e.isDefinition() || !e.definition().isPresent()) {
113 decls.add(e);
114 }
115 return null;
116 }
117
118 @Override
119 public Void visitHeader(HeaderTree ht, Void v) {
120 ht.declarations().forEach(decl -> decl.accept(this, null));
121 return null;
122 }
123
124 @Override
125 public Void visitStruct(StructTree s, Void v) {
126 /*
127 * If we're seeing a forward/backward declaration of
128 * a struct which is definied elsewhere in this compilation
129 * unit, ignore it. If no definition is found, we want to
130 * leave the declaration so that dummy definition will be
131 * generated.
132 *
133 * Example:
134 *
135 * struct Point; // <-- forward declaration
136 * struct Point { int i; int j; };
137 * struct Point3D { int i; int j; int k; };
138 * struct Point3D; // <-- backward declaration
139 */
140
141 // include this only if this is a definition or a declaration
142 // for which no definition is found elsewhere.
143 if (s.isDefinition() || !s.definition().isPresent()) {
144 decls.add(s);
145 }
146 return null;
147 }
148
149 @Override
150 public Void visitTypedef(TypedefTree tt, Void v) {
151 Optional<Tree> def = tt.typeDefinition();
152 if (def.isPresent()) {
153 Tree defTree = def.get();
154 if (defTree instanceof StructTree) {
155 if (defTree.name().isEmpty()) {
156 /**
157 * typedef struct { int x; int y; } Point
158 *
159 * is mapped to two Cursors by clang. First one for anonymous struct decl.
160 * and second one for typedef decl. We map it as a single named struct
161 * declaration.
162 */
163 replacements.put(defTree.cursor(), ((StructTree)defTree).withName(tt.name()));
164 return null;
165 } else if (defTree.name().equals(tt.name())) {
166 /*
167 * Remove redundant typedef like:
168 *
169 * typedef struct Point { int x; int y; } Point
170 */
171 return null;
172 }
173 } else if (defTree instanceof EnumTree && defTree.name().equals(tt.name())) {
174 /*
175 * Remove redundant typedef like:
176 *
177 * typedef enum Color { R, G, B} Color
178 */
179 return null;
180 }
181 }
182
183 decls.add(tt);
184 return null;
185 }
186
187 // test main to manually check this visitor
188 public static void main(String[] args) {
189 if (args.length == 0) {
190 System.err.println("Expected a header file");
191 return;
192 }
193
194 Parser p = new Parser(true);
195 List<Path> paths = Arrays.stream(args).map(Paths::get).collect(Collectors.toList());
196 Path builtinInc = Paths.get(System.getProperty("java.home"), "conf", "jextract");
197 List<String> clangArgs = List.of("-I" + builtinInc);
198 List<HeaderTree> headers = p.parse(paths, clangArgs);
199 TreePrinter printer = new TreePrinter();
200 TypedefHandler handler = new TypedefHandler();
201 for (HeaderTree ht : headers) {
202 handler.transform(ht).accept(printer, null);
203 }
204 }
205 }