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.List;
30 import java.util.stream.Collectors;
31 import com.sun.tools.jextract.parser.Parser;
32 import com.sun.tools.jextract.tree.EnumTree;
33 import com.sun.tools.jextract.tree.FieldTree;
34 import com.sun.tools.jextract.tree.LayoutUtils;
35 import com.sun.tools.jextract.tree.HeaderTree;
36 import com.sun.tools.jextract.tree.SimpleTreeVisitor;
37 import com.sun.tools.jextract.tree.StructTree;
38 import com.sun.tools.jextract.tree.Tree;
39 import com.sun.tools.jextract.tree.TreeMaker;
40 import com.sun.tools.jextract.tree.TreePrinter;
41 import jdk.internal.clang.Cursor;
42
43 /**
44 * This tree visitor handles the tree empty names encountered in the tree
45 * so that subsequent passes need not check tree.name() for empty string.
46 *
47 * 1. Names are generated & set for anonymous structs & unions.
48 * 2. Anonymous (bit) FieldTree instances are removed.
49 */
50 final class EmptyNameHandler extends SimpleTreeVisitor<Tree, Void> {
51 private final TreeMaker treeMaker = new TreeMaker();
52
53 HeaderTree transform(HeaderTree ht) {
54 return (HeaderTree)ht.accept(this, null);
55 }
56
57 // generate unique name for an empty name
58 private String generateName(Tree tree) {
59 return LayoutUtils.getName(tree);
60 }
61
62 @Override
63 public Tree defaultAction(Tree tree, Void v) {
64 return tree;
65 }
66
67 @Override
68 public Tree visitHeader(HeaderTree ht, Void v) {
69 List<Tree> decls = ht.declarations().stream().
70 map(decl -> decl.accept(this, null)).
71 collect(Collectors.toList());
72 return treeMaker.createHeader(ht.cursor(), ht.path(), decls);
73 }
74
75 @Override
76 public Tree visitStruct(StructTree s, Void v) {
77 // Common simple case. No nested names and no anonymous field names.
78 // We just need to check struct name itself is empty or not.
79 if (s.nestedTypes().isEmpty() && !hasAnonymousFields(s)) {
80 /*
81 * Examples:
82 *
83 * struct { int i } x; // global variable of anon. struct type
84 * void func(struct { int x; } p); // param of anon. struct type
85 */
86 if (s.name().isEmpty()) {
87 return s.withName(generateName(s));
88 } else {
89 // all fine with this struct
90 return s;
91 }
92 } else {
93 // handle all nested types
94 return renameRecursively(s);
95 }
96 }
97
98 // does the given struct has any anonymous (bit) field?
99 private boolean hasAnonymousFields(StructTree s) {
100 return s.fields().stream().map(f -> f.name().isEmpty()).findFirst().isPresent();
101 }
102
103 private StructTree renameRecursively(StructTree s) {
104 List<Tree> newDecls = s.declarations().stream().map(decl -> {
105 if (decl instanceof StructTree) {
106 return renameRecursively((StructTree)decl);
107 } else if (decl instanceof FieldTree && decl.name().isEmpty()) {
108 /*
109 * Skip anonymous fields. This happens in the following case:
110 *
111 * struct {
112 * int :23; // anonymous bit field
113 * int x:9;
114 * }
115 */
116
117 return null;
118 } else {
119 return decl;
120 }
121 }).filter(d -> d != null).collect(Collectors.toList());
122
123 return s.withNameAndDecls(generateName(s), newDecls);
124 }
125
126 // test main to manually check this visitor
127 public static void main(String[] args) {
128 if (args.length == 0) {
129 System.err.println("Expected a header file");
130 return;
131 }
132
133 Parser p = new Parser(true);
134 List<Path> paths = Arrays.stream(args).map(Paths::get).collect(Collectors.toList());
135 Path builtinInc = Paths.get(System.getProperty("java.home"), "conf", "jextract");
136 List<String> clangArgs = List.of("-I" + builtinInc);
137 List<HeaderTree> headers = p.parse(paths, clangArgs);
138 TreePrinter printer = new TreePrinter();
139 EmptyNameHandler handler = new EmptyNameHandler();
140 for (HeaderTree ht : headers) {
141 handler.transform(ht).accept(printer, null);
142 }
143 }
144 }