1 /*
 2  * Copyright (c) 2024, 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
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24  */
25 
26 package jdk.incubator.code.extern.impl;
27 
28 import jdk.incubator.code.extern.ExternalizedTypeElement;
29 import jdk.incubator.code.extern.impl.Tokens.TokenKind;
30 
31 import java.util.ArrayList;
32 import java.util.List;
33 
34 public final class DescParser {
35     private DescParser() {}
36 
37     /**
38      * Parse an externalized type element from its serialized textual form.
39      * @param desc the serialized externalized type element
40      * @return the externalized type element
41      */
42     public static ExternalizedTypeElement parseExTypeElem(String desc) {
43         Scanner s = Scanner.factory().newScanner(desc);
44         s.nextToken();
45         return parseExTypeElem(s);
46     }
47 
48     //    ExType:
49     //        ExTypeName
50     //        ExTypeName '<' ExType* '>'
51     //
52     //    ExTypeName:
53     //        ExIdentPart
54     //        ExIdentPart ExIdentSep ExIdentPart
55     //
56     //    ExIdentPart:
57     //        ident
58     //        string
59     //
60     //    ExIdentSep:
61     //        '.'
62     //        ':'
63     public static ExternalizedTypeElement parseExTypeElem(Lexer l) {
64         StringBuilder identifier = new StringBuilder();
65         identifier.append(parseExTypeNamePart(l));
66         while (l.is(TokenKind.DOT) || l.is(TokenKind.COLON)) {
67             identifier.append(l.token().kind.name);
68             l.nextToken();
69             identifier.append(parseExTypeNamePart(l));
70         }
71         List<ExternalizedTypeElement> args = new ArrayList<>();
72         if (l.is(TokenKind.LT)) {
73             l.accept(TokenKind.LT);
74             args.add(parseExTypeElem(l));
75             while (l.is(TokenKind.COMMA)) {
76                 l.accept(TokenKind.COMMA);
77                 args.add(parseExTypeElem(l));
78             }
79             l.accept(TokenKind.GT);
80         }
81         return new ExternalizedTypeElement(identifier.toString(), args);
82     }
83 
84     private static String parseExTypeNamePart(Lexer l) {
85         String namePart = switch (l.token().kind) {
86             case IDENTIFIER -> l.token().name();
87             case STRINGLITERAL -> "\"" + l.token().stringVal() + "\"";
88             default -> throw l.unexpected();
89         };
90         l.nextToken();
91         return namePart;
92     }
93 }