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1 /*
<lambda>null2  * Copyright (C) 2017 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package lexer
18 
19 import java.text.ParseException
20 import java.util.*
21 
22 object HidlLexer : ILexer {
23 
24     /**
25      * Given the text of a HIDL file, return a list ot tokens.
26      * Scanner moves forward only, but can check queued tokens.
27      */
28     override fun tokenize(str: String): List<Token> {
29         val tokens = mutableListOf<Token>()
30         //match line to '*/', check for anything after on same line
31         val matchToDocEnd = Regex("""(.*)\s+${Regex.escape(TokenGrammar.DOC_END.value)}(.*)$""")
32 
33         //pad delimiter tokens so the scanner picks them up.
34         val paddedStr = ILexer.padDelimiters(str)
35 
36         Scanner(paddedStr).use { scanner ->
37             while (scanner.hasNext()) {
38                 val token = scanner.next()
39 
40                 when (token) {
41                     //strip line comments
42                     TokenGrammar.COMMENT_LINE.value -> scanner.nextLine()
43 
44                     //strip block comments -- jump to comment close
45                     TokenGrammar.COMMENT_START.value -> {
46                         if (scanner.findWithinHorizon(Regex.escape(TokenGrammar.DOC_END.value), 0) == null) {
47                             throw ParseException("Unable to find closing comment marker", tokens.lastIndex)
48                         }
49                     }
50 
51                     //slurp text between /** and */ into a string,
52                     //tokenize string using the doc comment lexer,
53                     //append those tokens with the rest of the file tokens.
54                     TokenGrammar.DOC_START.value -> {
55                         tokens.add(TokenGrammar.newToken(token)) //doc_start
56                         //slurp everything until doc_end into a string. but want to keep newline formatting
57                         val sb = StringBuilder()
58                         while (scanner.hasNextLine()) {
59                             val line = scanner.nextLine()
60 
61                             val matches = matchToDocEnd.find(line)?.groups
62                             if (matches != null) {
63                                 if (!matches[2]!!.value.isNullOrBlank()) {
64                                     throw ParseException("No text after '*/' on same line: ${line}", 0)
65                                 }
66                                 //found doc_end
67                                 sb.append(matches[1]!!.value)
68                                 break
69                             } else {
70                                 sb.appendln(line)
71                             }
72                         }
73                         //tokenize comment string and append all
74                         tokens += DocLexer.tokenize(sb.toString())
75                         tokens.add(TokenGrammar.newToken(TokenGrammar.DOC_END.value)) //doc_end
76                     }
77 
78                     TokenGrammar.AT.value -> {
79                         tokens.add(TokenGrammar.newToken(token)) //'@'
80                         //determine if part of annotation tag
81                         for (annotation in TokenGrammar.annotations()) {
82                             if (scanner.hasNext(annotation.value)) {
83                                 scanner.next() //annotation tag
84                                 val annotationArgs = StringBuilder()
85                                 //capture any args: (...)
86                                 if (scanner.hasNext(Regex.escape(TokenGrammar.PAREN_OPEN.value))) {
87                                     while (!scanner.hasNext(Regex.escape(TokenGrammar.PAREN_CLOSE.value))) {
88                                         annotationArgs.append(scanner.next()).append(" ")
89                                     }
90                                     if (!scanner.hasNext()) {
91                                         throw ParseException("Unable to find closing annotation paren", tokens.lastIndex)
92                                     }
93                                     annotationArgs.append(scanner.next()) //')'
94                                 }
95                                 //all annotation args are embedded in the token's value
96                                 tokens.add(TokenGrammar.newToken(identifier = annotation, value = annotationArgs.toString()))
97                             }
98                         }
99                     }
100 
101                     else -> tokens.add(TokenGrammar.newToken(token))
102                 }
103             }
104         }
105         return tokens.toList()
106     }
107 }