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1 /**
2  * Copyright (c) 2021-2022 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #include "keywordsUtil.h"
17 
18 #include <gen/keywords.h>
19 #include <unicode/uchar.h>
20 
21 namespace panda::es2panda::lexer {
22 
23 enum class AsciiFlags : uint8_t {
24     NONE = 0,
25     ID_START = 1 << 0,
26     ID_CONTINUE = 1 << 1,
27 };
28 
operator |(AsciiFlags a,AsciiFlags b)29 constexpr AsciiFlags operator|(AsciiFlags a, AsciiFlags b)
30 {
31     using utype = std::underlying_type_t<AsciiFlags>;
32     return static_cast<AsciiFlags>(static_cast<utype>(a) | static_cast<utype>(b));
33 }
34 
operator &(AsciiFlags a,AsciiFlags b)35 inline std::underlying_type_t<AsciiFlags> operator&(AsciiFlags a, AsciiFlags b)
36 {
37     using utype = std::underlying_type_t<AsciiFlags>;
38     /* NOLINTNEXTLINE(hicpp-signed-bitwise) */
39     return static_cast<utype>(static_cast<utype>(a) & static_cast<utype>(b));
40 }
41 
42 constexpr std::array<AsciiFlags, 128> ASCII_FLAGS = {{
43     AsciiFlags::NONE,                               /* NUL */
44     AsciiFlags::NONE,                               /* SOH */
45     AsciiFlags::NONE,                               /* STX */
46     AsciiFlags::NONE,                               /* ETX */
47     AsciiFlags::NONE,                               /* EOT */
48     AsciiFlags::NONE,                               /* ENQ */
49     AsciiFlags::NONE,                               /* ACK */
50     AsciiFlags::NONE,                               /* BEL */
51     AsciiFlags::NONE,                               /* BS */
52     AsciiFlags::NONE,                               /* TAB */
53     AsciiFlags::NONE,                               /* LF */
54     AsciiFlags::NONE,                               /* VT */
55     AsciiFlags::NONE,                               /* FF */
56     AsciiFlags::NONE,                               /* CR */
57     AsciiFlags::NONE,                               /* SO */
58     AsciiFlags::NONE,                               /* SI */
59     AsciiFlags::NONE,                               /* DLE */
60     AsciiFlags::NONE,                               /* DC1 */
61     AsciiFlags::NONE,                               /* DC2 */
62     AsciiFlags::NONE,                               /* DC3 */
63     AsciiFlags::NONE,                               /* DC4 */
64     AsciiFlags::NONE,                               /* NAK */
65     AsciiFlags::NONE,                               /* SYN */
66     AsciiFlags::NONE,                               /* ETB */
67     AsciiFlags::NONE,                               /* CAN */
68     AsciiFlags::NONE,                               /* EM */
69     AsciiFlags::NONE,                               /* SUB */
70     AsciiFlags::NONE,                               /* ESC */
71     AsciiFlags::NONE,                               /* FS */
72     AsciiFlags::NONE,                               /* GS */
73     AsciiFlags::NONE,                               /* RS */
74     AsciiFlags::NONE,                               /* US */
75     AsciiFlags::NONE,                               /* Space */
76     AsciiFlags::NONE,                               /* ! */
77     AsciiFlags::NONE,                               /* " */
78     AsciiFlags::NONE,                               /* # */
79     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* $ */
80     AsciiFlags::NONE,                               /* % */
81     AsciiFlags::NONE,                               /* & */
82     AsciiFlags::NONE,                               /* ' */
83     AsciiFlags::NONE,                               /* ( */
84     AsciiFlags::NONE,                               /* ) */
85     AsciiFlags::NONE,                               /* * */
86     AsciiFlags::NONE,                               /* + */
87     AsciiFlags::NONE,                               /* , */
88     AsciiFlags::NONE,                               /* - */
89     AsciiFlags::NONE,                               /* . */
90     AsciiFlags::NONE,                               /* / */
91     AsciiFlags::ID_CONTINUE,                        /* 0 */
92     AsciiFlags::ID_CONTINUE,                        /* 1 */
93     AsciiFlags::ID_CONTINUE,                        /* 2 */
94     AsciiFlags::ID_CONTINUE,                        /* 3 */
95     AsciiFlags::ID_CONTINUE,                        /* 4 */
96     AsciiFlags::ID_CONTINUE,                        /* 5 */
97     AsciiFlags::ID_CONTINUE,                        /* 6 */
98     AsciiFlags::ID_CONTINUE,                        /* 7 */
99     AsciiFlags::ID_CONTINUE,                        /* 8 */
100     AsciiFlags::ID_CONTINUE,                        /* 9 */
101     AsciiFlags::NONE,                               /* : */
102     AsciiFlags::NONE,                               /* ; */
103     AsciiFlags::NONE,                               /* < */
104     AsciiFlags::NONE,                               /* = */
105     AsciiFlags::NONE,                               /* > */
106     AsciiFlags::NONE,                               /* ? */
107     AsciiFlags::NONE,                               /* @ */
108     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* A */
109     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* B */
110     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* C */
111     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* D */
112     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* E */
113     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* F */
114     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* G */
115     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* H */
116     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* I */
117     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* J */
118     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* K */
119     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* L */
120     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* M */
121     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* N */
122     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* O */
123     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* P */
124     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* Q */
125     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* R */
126     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* S */
127     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* T */
128     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* U */
129     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* V */
130     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* W */
131     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* X */
132     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* Y */
133     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* Z */
134     AsciiFlags::NONE,                               /* [ */
135     AsciiFlags::NONE,                               /* \ */
136     AsciiFlags::NONE,                               /* ] */
137     AsciiFlags::NONE,                               /* ^ */
138     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* _ */
139     AsciiFlags::NONE,                               /* ` */
140     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* a */
141     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* b */
142     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* c */
143     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* d */
144     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* e */
145     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* f */
146     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* g */
147     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* h */
148     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* i */
149     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* j */
150     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* k */
151     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* l */
152     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* m */
153     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* n */
154     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* o */
155     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* p */
156     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* q */
157     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* r */
158     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* s */
159     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* t */
160     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* u */
161     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* v */
162     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* w */
163     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* x */
164     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* y */
165     AsciiFlags::ID_START | AsciiFlags::ID_CONTINUE, /* z */
166     AsciiFlags::NONE,                               /* { */
167     AsciiFlags::NONE,                               /* | */
168     AsciiFlags::NONE,                               /* } */
169     AsciiFlags::NONE,                               /* ~ */
170     AsciiFlags::NONE                                /* DEL */
171 }};
172 
IsIdentifierStart(char32_t cp)173 bool KeywordsUtil::IsIdentifierStart(char32_t cp)
174 {
175     if (cp < LEX_ASCII_MAX_BITS) {
176         return (ASCII_FLAGS[cp] & AsciiFlags::ID_START) != 0;
177     }
178     // Unicode {xxxxx} may consist of 4 bytes information and cannot be forcibly converted to 2 bytes
179     auto uchar = static_cast<UChar32>(cp);
180     return u_hasBinaryProperty(uchar, UCHAR_ID_START);
181 }
182 
IsIdentifierPart(char32_t cp)183 bool KeywordsUtil::IsIdentifierPart(char32_t cp)
184 {
185     if (cp < LEX_ASCII_MAX_BITS) {
186         return (ASCII_FLAGS[cp] & AsciiFlags::ID_CONTINUE) != 0;
187     }
188 
189     /**
190      * u_isIDPart or Other_ID_Continue characters or ZWJ/ZWNJ.
191      * Unicode {xxxxx} may consist of 4 bytes information and cannot be forcibly converted to 2 bytes
192      */
193     auto uchar = static_cast<UChar32>(cp);
194     return (u_hasBinaryProperty(uchar, UCHAR_ID_CONTINUE) || cp == LEX_CHAR_ZWNJ || cp == LEX_CHAR_ZWJ);
195 }
196 
ScanIdentifierStart(char32_t cp)197 void KeywordsUtil::ScanIdentifierStart(char32_t cp)
198 {
199     if (!KeywordsUtil::IsIdentifierStart(cp)) {
200         lexer_->ThrowError("Expected an identifier");
201     }
202 
203     cp_ = cp;
204     const auto map = KeywordsMap::Map(cp);
205     ScanIdContinueMaybeKeyword(map);
206 }
207 
ScanIdContinue()208 void KeywordsUtil::ScanIdContinue()
209 {
210     util::UString ident(lexer_->Allocator());
211     size_t startPos = lexer_->GetToken().Start().index;
212 
213     if (HasEscape()) {
214         ident.Append(cp_);
215         startPos = Iterator().Index();
216     }
217 
218     auto escapeEnd = startPos;
219 
220     do {
221         if (Iterator().Peek() == LEX_CHAR_BACKSLASH) {
222             ident.Append(lexer_->SourceView(escapeEnd, Iterator().Index()));
223 
224             auto cp = ScanUnicodeEscapeSequence();
225             if (!IsIdentifierPart(cp)) {
226                 lexer_->ThrowError("Invalid identifier part");
227             }
228 
229             escapeEnd = Iterator().Index();
230             ident.Append(cp);
231             continue;
232         }
233 
234         size_t cpSize {};
235         auto cp = Iterator().PeekCp(&cpSize);
236         if (!IsIdentifierPart(cp)) {
237             break;
238         }
239 
240         Iterator().Forward(cpSize);
241     } while (true);
242 
243     lexer_->GetToken().type_ = TokenType::LITERAL_IDENT;
244     lexer_->GetToken().keywordType_ = TokenType::EOS;
245 
246     if (HasEscape()) {
247         ident.Append(lexer_->SourceView(escapeEnd, Iterator().Index()));
248         lexer_->GetToken().src_ = ident.View();
249     } else {
250         lexer_->GetToken().src_ = lexer_->SourceView(startPos, Iterator().Index());
251     }
252 }
253 
ScanIdContinueMaybeKeyword(Span<const KeywordString> map)254 void KeywordsUtil::ScanIdContinueMaybeKeyword(Span<const KeywordString> map)
255 {
256     ScanIdContinue();
257 
258     if (!HasEscape() || map.empty()) {
259         return;
260     }
261 
262     const auto &str = lexer_->GetToken().Ident().Utf8();
263 
264     int start = 0;
265     int end = static_cast<int>(map.size());
266     int middle = end / 2;
267 
268     while (true) {
269         const auto &kws = map[middle];
270 
271         int relation = str.compare(kws.str);
272         if (relation == 0) {
273             Keywords::SetKeyword(this, kws);
274         }
275 
276         if (relation > 0) {
277             start = middle + 1;
278         } else {
279             end = middle;
280         }
281 
282         middle = (start + end) / 2;
283 
284         if (start >= end) {
285             return;
286         }
287     }
288 }
289 
ScanUnicodeEscapeSequence()290 char32_t KeywordsUtil::ScanUnicodeEscapeSequence()
291 {
292     ASSERT(Iterator().Peek() == LEX_CHAR_BACKSLASH);
293 
294     lexer_->GetToken().flags_ |= lexer::TokenFlags::HAS_ESCAPE;
295 
296     Iterator().Forward(1);
297 
298     if (Iterator().Peek() != LEX_CHAR_LOWERCASE_U) {
299         return util::StringView::Iterator::INVALID_CP;
300     }
301 
302     return lexer_->ScanUnicodeEscapeSequence();
303 }
304 
305 }  // namespace panda::es2panda::lexer
306