1//===--- Token.h - Token interface ------------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines the Token interface.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_CLANG_LEX_TOKEN_H
14#define LLVM_CLANG_LEX_TOKEN_H
15
16#include "clang/Basic/SourceLocation.h"
17#include "clang/Basic/TokenKinds.h"
18#include "llvm/ADT/StringRef.h"
19#include <cassert>
20
21namespace clang {
22
23class IdentifierInfo;
24
25/// Token - This structure provides full information about a lexed token.
26/// It is not intended to be space efficient, it is intended to return as much
27/// information as possible about each returned token. This is expected to be
28/// compressed into a smaller form if memory footprint is important.
29///
30/// The parser can create a special "annotation token" representing a stream of
31/// tokens that were parsed and semantically resolved, e.g.: "foo::MyClass<int>"
32/// can be represented by a single typename annotation token that carries
33/// information about the SourceRange of the tokens and the type object.
34class Token {
35 /// The location of the token. This is actually a SourceLocation.
36 unsigned Loc;
37
38 // Conceptually these next two fields could be in a union. However, this
39 // causes gcc 4.2 to pessimize LexTokenInternal, a very performance critical
40 // routine. Keeping as separate members with casts until a more beautiful fix
41 // presents itself.
42
43 /// UintData - This holds either the length of the token text, when
44 /// a normal token, or the end of the SourceRange when an annotation
45 /// token.
46 unsigned UintData;
47
48 /// PtrData - This is a union of four different pointer types, which depends
49 /// on what type of token this is:
50 /// Identifiers, keywords, etc:
51 /// This is an IdentifierInfo*, which contains the uniqued identifier
52 /// spelling.
53 /// Literals: isLiteral() returns true.
54 /// This is a pointer to the start of the token in a text buffer, which
55 /// may be dirty (have trigraphs / escaped newlines).
56 /// Annotations (resolved type names, C++ scopes, etc): isAnnotation().
57 /// This is a pointer to sema-specific data for the annotation token.
58 /// Eof:
59 // This is a pointer to a Decl.
60 /// Other:
61 /// This is null.
62 void *PtrData;
63
64 /// Kind - The actual flavor of token this is.
65 tok::TokenKind Kind;
66
67 /// Flags - Bits we track about this token, members of the TokenFlags enum.
68 unsigned short Flags;
69
70public:
71 // Various flags set per token:
72 enum TokenFlags {
73 StartOfLine = 0x01, // At start of line or only after whitespace
74 // (considering the line after macro expansion).
75 LeadingSpace = 0x02, // Whitespace exists before this token (considering
76 // whitespace after macro expansion).
77 DisableExpand = 0x04, // This identifier may never be macro expanded.
78 NeedsCleaning = 0x08, // Contained an escaped newline or trigraph.
79 LeadingEmptyMacro = 0x10, // Empty macro exists before this token.
80 HasUDSuffix = 0x20, // This string or character literal has a ud-suffix.
81 HasUCN = 0x40, // This identifier contains a UCN.
82 IgnoredComma = 0x80, // This comma is not a macro argument separator (MS).
83 StringifiedInMacro = 0x100, // This string or character literal is formed by
84 // macro stringizing or charizing operator.
85 CommaAfterElided = 0x200, // The comma following this token was elided (MS).
86 IsEditorPlaceholder = 0x400, // This identifier is a placeholder.
87 };
88
89 tok::TokenKind getKind() const { return Kind; }
90 void setKind(tok::TokenKind K) { Kind = K; }
91
92 /// is/isNot - Predicates to check if this token is a specific kind, as in
93 /// "if (Tok.is(tok::l_brace)) {...}".
94 bool is(tok::TokenKind K) const { return Kind == K; }
95 bool isNot(tok::TokenKind K) const { return Kind != K; }
96 bool isOneOf(tok::TokenKind K1, tok::TokenKind K2) const {
97 return is(K1) || is(K2);
98 }
99 template <typename... Ts>
100 bool isOneOf(tok::TokenKind K1, tok::TokenKind K2, Ts... Ks) const {
101 return is(K1) || isOneOf(K2, Ks...);
102 }
103
104 /// Return true if this is a raw identifier (when lexing
105 /// in raw mode) or a non-keyword identifier (when lexing in non-raw mode).
106 bool isAnyIdentifier() const {
107 return tok::isAnyIdentifier(getKind());
108 }
109
110 /// Return true if this is a "literal", like a numeric
111 /// constant, string, etc.
112 bool isLiteral() const {
113 return tok::isLiteral(getKind());
114 }
115
116 /// Return true if this is any of tok::annot_* kind tokens.
117 bool isAnnotation() const {
118 return tok::isAnnotation(getKind());
119 }
120
121 /// Return a source location identifier for the specified
122 /// offset in the current file.
123 SourceLocation getLocation() const {
124 return SourceLocation::getFromRawEncoding(Loc);
125 }
126 unsigned getLength() const {
127 assert(!isAnnotation() && "Annotation tokens have no length field");
128 return UintData;
129 }
130
131 void setLocation(SourceLocation L) { Loc = L.getRawEncoding(); }
132 void setLength(unsigned Len) {
133 assert(!isAnnotation() && "Annotation tokens have no length field");
134 UintData = Len;
135 }
136
137 SourceLocation getAnnotationEndLoc() const {
138 assert(isAnnotation() && "Used AnnotEndLocID on non-annotation token");
139 return SourceLocation::getFromRawEncoding(UintData ? UintData : Loc);
140 }
141 void setAnnotationEndLoc(SourceLocation L) {
142 assert(isAnnotation() && "Used AnnotEndLocID on non-annotation token");
143 UintData = L.getRawEncoding();
144 }
145
146 SourceLocation getLastLoc() const {
147 return isAnnotation() ? getAnnotationEndLoc() : getLocation();
148 }
149
150 SourceLocation getEndLoc() const {
151 return isAnnotation() ? getAnnotationEndLoc()
152 : getLocation().getLocWithOffset(getLength());
153 }
154
155 /// SourceRange of the group of tokens that this annotation token
156 /// represents.
157 SourceRange getAnnotationRange() const {
158 return SourceRange(getLocation(), getAnnotationEndLoc());
159 }
160 void setAnnotationRange(SourceRange R) {
161 setLocation(R.getBegin());
162 setAnnotationEndLoc(R.getEnd());
163 }
164
165 const char *getName() const { return tok::getTokenName(Kind); }
166
167 /// Reset all flags to cleared.
168 void startToken() {
169 Kind = tok::unknown;
170 Flags = 0;
171 PtrData = nullptr;
172 UintData = 0;
173 Loc = SourceLocation().getRawEncoding();
174 }
175
176 IdentifierInfo *getIdentifierInfo() const {
177 assert(isNot(tok::raw_identifier) &&
178 "getIdentifierInfo() on a tok::raw_identifier token!");
179 assert(!isAnnotation() &&
180 "getIdentifierInfo() on an annotation token!");
181 if (isLiteral()) return nullptr;
182 if (is(tok::eof)) return nullptr;
183 return (IdentifierInfo*) PtrData;
184 }
185 void setIdentifierInfo(IdentifierInfo *II) {
186 PtrData = (void*) II;
187 }
188
189 const void *getEofData() const {
190 assert(is(tok::eof));
191 return reinterpret_cast<const void *>(PtrData);
192 }
193 void setEofData(const void *D) {
194 assert(is(tok::eof));
195 assert(!PtrData);
196 PtrData = const_cast<void *>(D);
197 }
198
199 /// getRawIdentifier - For a raw identifier token (i.e., an identifier
200 /// lexed in raw mode), returns a reference to the text substring in the
201 /// buffer if known.
202 StringRef getRawIdentifier() const {
203 assert(is(tok::raw_identifier));
204 return StringRef(reinterpret_cast<const char *>(PtrData), getLength());
205 }
206 void setRawIdentifierData(const char *Ptr) {
207 assert(is(tok::raw_identifier));
208 PtrData = const_cast<char*>(Ptr);
209 }
210
211 /// getLiteralData - For a literal token (numeric constant, string, etc), this
212 /// returns a pointer to the start of it in the text buffer if known, null
213 /// otherwise.
214 const char *getLiteralData() const {
215 assert(isLiteral() && "Cannot get literal data of non-literal");
216 return reinterpret_cast<const char*>(PtrData);
217 }
218 void setLiteralData(const char *Ptr) {
219 assert(isLiteral() && "Cannot set literal data of non-literal");
220 PtrData = const_cast<char*>(Ptr);
221 }
222
223 void *getAnnotationValue() const {
224 assert(isAnnotation() && "Used AnnotVal on non-annotation token");
225 return PtrData;
226 }
227 void setAnnotationValue(void *val) {
228 assert(isAnnotation() && "Used AnnotVal on non-annotation token");
229 PtrData = val;
230 }
231
232 /// Set the specified flag.
233 void setFlag(TokenFlags Flag) {
234 Flags |= Flag;
235 }
236
237 /// Get the specified flag.
238 bool getFlag(TokenFlags Flag) const {
239 return (Flags & Flag) != 0;
240 }
241
242 /// Unset the specified flag.
243 void clearFlag(TokenFlags Flag) {
244 Flags &= ~Flag;
245 }
246
247 /// Return the internal represtation of the flags.
248 ///
249 /// This is only intended for low-level operations such as writing tokens to
250 /// disk.
251 unsigned getFlags() const {
252 return Flags;
253 }
254
255 /// Set a flag to either true or false.
256 void setFlagValue(TokenFlags Flag, bool Val) {
257 if (Val)
258 setFlag(Flag);
259 else
260 clearFlag(Flag);
261 }
262
263 /// isAtStartOfLine - Return true if this token is at the start of a line.
264 ///
265 bool isAtStartOfLine() const { return getFlag(StartOfLine); }
266
267 /// Return true if this token has whitespace before it.
268 ///
269 bool hasLeadingSpace() const { return getFlag(LeadingSpace); }
270
271 /// Return true if this identifier token should never
272 /// be expanded in the future, due to C99 6.10.3.4p2.
273 bool isExpandDisabled() const { return getFlag(DisableExpand); }
274
275 /// Return true if we have an ObjC keyword identifier.
276 bool isObjCAtKeyword(tok::ObjCKeywordKind objcKey) const;
277
278 /// Return the ObjC keyword kind.
279 tok::ObjCKeywordKind getObjCKeywordID() const;
280
281 /// Return true if this token has trigraphs or escaped newlines in it.
282 bool needsCleaning() const { return getFlag(NeedsCleaning); }
283
284 /// Return true if this token has an empty macro before it.
285 ///
286 bool hasLeadingEmptyMacro() const { return getFlag(LeadingEmptyMacro); }
287
288 /// Return true if this token is a string or character literal which
289 /// has a ud-suffix.
290 bool hasUDSuffix() const { return getFlag(HasUDSuffix); }
291
292 /// Returns true if this token contains a universal character name.
293 bool hasUCN() const { return getFlag(HasUCN); }
294
295 /// Returns true if this token is formed by macro by stringizing or charizing
296 /// operator.
297 bool stringifiedInMacro() const { return getFlag(StringifiedInMacro); }
298
299 /// Returns true if the comma after this token was elided.
300 bool commaAfterElided() const { return getFlag(CommaAfterElided); }
301
302 /// Returns true if this token is an editor placeholder.
303 ///
304 /// Editor placeholders are produced by the code-completion engine and are
305 /// represented as characters between '<#' and '#>' in the source code. The
306 /// lexer uses identifier tokens to represent placeholders.
307 bool isEditorPlaceholder() const { return getFlag(IsEditorPlaceholder); }
308};
309
310/// Information about the conditional stack (\#if directives)
311/// currently active.
312struct PPConditionalInfo {
313 /// Location where the conditional started.
314 SourceLocation IfLoc;
315
316 /// True if this was contained in a skipping directive, e.g.,
317 /// in a "\#if 0" block.
318 bool WasSkipping;
319
320 /// True if we have emitted tokens already, and now we're in
321 /// an \#else block or something. Only useful in Skipping blocks.
322 bool FoundNonSkip;
323
324 /// True if we've seen a \#else in this block. If so,
325 /// \#elif/\#else directives are not allowed.
326 bool FoundElse;
327};
328
329} // end namespace clang
330
331#endif // LLVM_CLANG_LEX_TOKEN_H
332