| 1 | //===- Lexer.h - C Language Family Lexer ------------------------*- 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 Lexer interface. |
| 10 | // |
| 11 | //===----------------------------------------------------------------------===// |
| 12 | |
| 13 | #ifndef LLVM_CLANG_LEX_LEXER_H |
| 14 | #define LLVM_CLANG_LEX_LEXER_H |
| 15 | |
| 16 | #include "clang/Basic/LangOptions.h" |
| 17 | #include "clang/Basic/SourceLocation.h" |
| 18 | #include "clang/Basic/TokenKinds.h" |
| 19 | #include "clang/Lex/PreprocessorLexer.h" |
| 20 | #include "clang/Lex/Token.h" |
| 21 | #include "llvm/ADT/Optional.h" |
| 22 | #include "llvm/ADT/SmallVector.h" |
| 23 | #include "llvm/ADT/StringRef.h" |
| 24 | #include <cassert> |
| 25 | #include <cstdint> |
| 26 | #include <string> |
| 27 | |
| 28 | namespace llvm { |
| 29 | |
| 30 | class MemoryBuffer; |
| 31 | |
| 32 | } // namespace llvm |
| 33 | |
| 34 | namespace clang { |
| 35 | |
| 36 | class DiagnosticBuilder; |
| 37 | class Preprocessor; |
| 38 | class SourceManager; |
| 39 | |
| 40 | /// ConflictMarkerKind - Kinds of conflict marker which the lexer might be |
| 41 | /// recovering from. |
| 42 | enum ConflictMarkerKind { |
| 43 | /// Not within a conflict marker. |
| 44 | CMK_None, |
| 45 | |
| 46 | /// A normal or diff3 conflict marker, initiated by at least 7 "<"s, |
| 47 | /// separated by at least 7 "="s or "|"s, and terminated by at least 7 ">"s. |
| 48 | CMK_Normal, |
| 49 | |
| 50 | /// A Perforce-style conflict marker, initiated by 4 ">"s, |
| 51 | /// separated by 4 "="s, and terminated by 4 "<"s. |
| 52 | CMK_Perforce |
| 53 | }; |
| 54 | |
| 55 | /// Describes the bounds (start, size) of the preamble and a flag required by |
| 56 | /// PreprocessorOptions::PrecompiledPreambleBytes. |
| 57 | /// The preamble includes the BOM, if any. |
| 58 | struct PreambleBounds { |
| 59 | /// Size of the preamble in bytes. |
| 60 | unsigned Size; |
| 61 | |
| 62 | /// Whether the preamble ends at the start of a new line. |
| 63 | /// |
| 64 | /// Used to inform the lexer as to whether it's starting at the beginning of |
| 65 | /// a line after skipping the preamble. |
| 66 | bool PreambleEndsAtStartOfLine; |
| 67 | |
| 68 | PreambleBounds(unsigned Size, bool PreambleEndsAtStartOfLine) |
| 69 | : Size(Size), PreambleEndsAtStartOfLine(PreambleEndsAtStartOfLine) {} |
| 70 | }; |
| 71 | |
| 72 | /// Lexer - This provides a simple interface that turns a text buffer into a |
| 73 | /// stream of tokens. This provides no support for file reading or buffering, |
| 74 | /// or buffering/seeking of tokens, only forward lexing is supported. It relies |
| 75 | /// on the specified Preprocessor object to handle preprocessor directives, etc. |
| 76 | class Lexer : public PreprocessorLexer { |
| 77 | friend class Preprocessor; |
| 78 | |
| 79 | void anchor() override; |
| 80 | |
| 81 | //===--------------------------------------------------------------------===// |
| 82 | // Constant configuration values for this lexer. |
| 83 | |
| 84 | // Start of the buffer. |
| 85 | const char *BufferStart; |
| 86 | |
| 87 | // End of the buffer. |
| 88 | const char *BufferEnd; |
| 89 | |
| 90 | // Location for start of file. |
| 91 | SourceLocation FileLoc; |
| 92 | |
| 93 | // LangOpts enabled by this language (cache). |
| 94 | LangOptions LangOpts; |
| 95 | |
| 96 | // True if lexer for _Pragma handling. |
| 97 | bool Is_PragmaLexer; |
| 98 | |
| 99 | //===--------------------------------------------------------------------===// |
| 100 | // Context-specific lexing flags set by the preprocessor. |
| 101 | // |
| 102 | |
| 103 | /// ExtendedTokenMode - The lexer can optionally keep comments and whitespace |
| 104 | /// and return them as tokens. This is used for -C and -CC modes, and |
| 105 | /// whitespace preservation can be useful for some clients that want to lex |
| 106 | /// the file in raw mode and get every character from the file. |
| 107 | /// |
| 108 | /// When this is set to 2 it returns comments and whitespace. When set to 1 |
| 109 | /// it returns comments, when it is set to 0 it returns normal tokens only. |
| 110 | unsigned char ExtendedTokenMode; |
| 111 | |
| 112 | //===--------------------------------------------------------------------===// |
| 113 | // Context that changes as the file is lexed. |
| 114 | // NOTE: any state that mutates when in raw mode must have save/restore code |
| 115 | // in Lexer::isNextPPTokenLParen. |
| 116 | |
| 117 | // BufferPtr - Current pointer into the buffer. This is the next character |
| 118 | // to be lexed. |
| 119 | const char *BufferPtr; |
| 120 | |
| 121 | // IsAtStartOfLine - True if the next lexed token should get the "start of |
| 122 | // line" flag set on it. |
| 123 | bool IsAtStartOfLine; |
| 124 | |
| 125 | bool IsAtPhysicalStartOfLine; |
| 126 | |
| 127 | bool HasLeadingSpace; |
| 128 | |
| 129 | bool HasLeadingEmptyMacro; |
| 130 | |
| 131 | // CurrentConflictMarkerState - The kind of conflict marker we are handling. |
| 132 | ConflictMarkerKind CurrentConflictMarkerState; |
| 133 | |
| 134 | void InitLexer(const char *BufStart, const char *BufPtr, const char *BufEnd); |
| 135 | |
| 136 | public: |
| 137 | /// Lexer constructor - Create a new lexer object for the specified buffer |
| 138 | /// with the specified preprocessor managing the lexing process. This lexer |
| 139 | /// assumes that the associated file buffer and Preprocessor objects will |
| 140 | /// outlive it, so it doesn't take ownership of either of them. |
| 141 | Lexer(FileID FID, const llvm::MemoryBuffer *InputFile, Preprocessor &PP); |
| 142 | |
| 143 | /// Lexer constructor - Create a new raw lexer object. This object is only |
| 144 | /// suitable for calls to 'LexFromRawLexer'. This lexer assumes that the |
| 145 | /// text range will outlive it, so it doesn't take ownership of it. |
| 146 | Lexer(SourceLocation FileLoc, const LangOptions &LangOpts, |
| 147 | const char *BufStart, const char *BufPtr, const char *BufEnd); |
| 148 | |
| 149 | /// Lexer constructor - Create a new raw lexer object. This object is only |
| 150 | /// suitable for calls to 'LexFromRawLexer'. This lexer assumes that the |
| 151 | /// text range will outlive it, so it doesn't take ownership of it. |
| 152 | Lexer(FileID FID, const llvm::MemoryBuffer *FromFile, |
| 153 | const SourceManager &SM, const LangOptions &LangOpts); |
| 154 | |
| 155 | Lexer(const Lexer &) = delete; |
| 156 | Lexer &operator=(const Lexer &) = delete; |
| 157 | |
| 158 | /// Create_PragmaLexer: Lexer constructor - Create a new lexer object for |
| 159 | /// _Pragma expansion. This has a variety of magic semantics that this method |
| 160 | /// sets up. It returns a new'd Lexer that must be delete'd when done. |
| 161 | static Lexer *Create_PragmaLexer(SourceLocation SpellingLoc, |
| 162 | SourceLocation ExpansionLocStart, |
| 163 | SourceLocation ExpansionLocEnd, |
| 164 | unsigned TokLen, Preprocessor &PP); |
| 165 | |
| 166 | /// getLangOpts - Return the language features currently enabled. |
| 167 | /// NOTE: this lexer modifies features as a file is parsed! |
| 168 | const LangOptions &getLangOpts() const { return LangOpts; } |
| 169 | |
| 170 | /// getFileLoc - Return the File Location for the file we are lexing out of. |
| 171 | /// The physical location encodes the location where the characters come from, |
| 172 | /// the virtual location encodes where we should *claim* the characters came |
| 173 | /// from. Currently this is only used by _Pragma handling. |
| 174 | SourceLocation getFileLoc() const { return FileLoc; } |
| 175 | |
| 176 | private: |
| 177 | /// Lex - Return the next token in the file. If this is the end of file, it |
| 178 | /// return the tok::eof token. This implicitly involves the preprocessor. |
| 179 | bool Lex(Token &Result); |
| 180 | |
| 181 | public: |
| 182 | /// isPragmaLexer - Returns true if this Lexer is being used to lex a pragma. |
| 183 | bool isPragmaLexer() const { return Is_PragmaLexer; } |
| 184 | |
| 185 | private: |
| 186 | /// IndirectLex - An indirect call to 'Lex' that can be invoked via |
| 187 | /// the PreprocessorLexer interface. |
| 188 | void IndirectLex(Token &Result) override { Lex(Result); } |
| 189 | |
| 190 | public: |
| 191 | /// LexFromRawLexer - Lex a token from a designated raw lexer (one with no |
| 192 | /// associated preprocessor object. Return true if the 'next character to |
| 193 | /// read' pointer points at the end of the lexer buffer, false otherwise. |
| 194 | bool LexFromRawLexer(Token &Result) { |
| 195 | (0) . __assert_fail ("LexingRawMode && \"Not already in raw mode!\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/Lexer.h", 195, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(LexingRawMode && "Not already in raw mode!"); |
| 196 | Lex(Result); |
| 197 | // Note that lexing to the end of the buffer doesn't implicitly delete the |
| 198 | // lexer when in raw mode. |
| 199 | return BufferPtr == BufferEnd; |
| 200 | } |
| 201 | |
| 202 | /// isKeepWhitespaceMode - Return true if the lexer should return tokens for |
| 203 | /// every character in the file, including whitespace and comments. This |
| 204 | /// should only be used in raw mode, as the preprocessor is not prepared to |
| 205 | /// deal with the excess tokens. |
| 206 | bool isKeepWhitespaceMode() const { |
| 207 | return ExtendedTokenMode > 1; |
| 208 | } |
| 209 | |
| 210 | /// SetKeepWhitespaceMode - This method lets clients enable or disable |
| 211 | /// whitespace retention mode. |
| 212 | void SetKeepWhitespaceMode(bool Val) { |
| 213 | (0) . __assert_fail ("(!Val || LexingRawMode || LangOpts.TraditionalCPP) && \"Can only retain whitespace in raw mode or -traditional-cpp\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/Lexer.h", 214, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert((!Val || LexingRawMode || LangOpts.TraditionalCPP) && |
| 214 | (0) . __assert_fail ("(!Val || LexingRawMode || LangOpts.TraditionalCPP) && \"Can only retain whitespace in raw mode or -traditional-cpp\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/Lexer.h", 214, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true"> "Can only retain whitespace in raw mode or -traditional-cpp"); |
| 215 | ExtendedTokenMode = Val ? 2 : 0; |
| 216 | } |
| 217 | |
| 218 | /// inKeepCommentMode - Return true if the lexer should return comments as |
| 219 | /// tokens. |
| 220 | bool inKeepCommentMode() const { |
| 221 | return ExtendedTokenMode > 0; |
| 222 | } |
| 223 | |
| 224 | /// SetCommentRetentionMode - Change the comment retention mode of the lexer |
| 225 | /// to the specified mode. This is really only useful when lexing in raw |
| 226 | /// mode, because otherwise the lexer needs to manage this. |
| 227 | void SetCommentRetentionState(bool Mode) { |
| 228 | (0) . __assert_fail ("!isKeepWhitespaceMode() && \"Can't play with comment retention state when retaining whitespace\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/Lexer.h", 229, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(!isKeepWhitespaceMode() && |
| 229 | (0) . __assert_fail ("!isKeepWhitespaceMode() && \"Can't play with comment retention state when retaining whitespace\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/Lexer.h", 229, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true"> "Can't play with comment retention state when retaining whitespace"); |
| 230 | ExtendedTokenMode = Mode ? 1 : 0; |
| 231 | } |
| 232 | |
| 233 | /// Sets the extended token mode back to its initial value, according to the |
| 234 | /// language options and preprocessor. This controls whether the lexer |
| 235 | /// produces comment and whitespace tokens. |
| 236 | /// |
| 237 | /// This requires the lexer to have an associated preprocessor. A standalone |
| 238 | /// lexer has nothing to reset to. |
| 239 | void resetExtendedTokenMode(); |
| 240 | |
| 241 | /// Gets source code buffer. |
| 242 | StringRef getBuffer() const { |
| 243 | return StringRef(BufferStart, BufferEnd - BufferStart); |
| 244 | } |
| 245 | |
| 246 | /// ReadToEndOfLine - Read the rest of the current preprocessor line as an |
| 247 | /// uninterpreted string. This switches the lexer out of directive mode. |
| 248 | void ReadToEndOfLine(SmallVectorImpl<char> *Result = nullptr); |
| 249 | |
| 250 | |
| 251 | /// Diag - Forwarding function for diagnostics. This translate a source |
| 252 | /// position in the current buffer into a SourceLocation object for rendering. |
| 253 | DiagnosticBuilder Diag(const char *Loc, unsigned DiagID) const; |
| 254 | |
| 255 | /// getSourceLocation - Return a source location identifier for the specified |
| 256 | /// offset in the current file. |
| 257 | SourceLocation getSourceLocation(const char *Loc, unsigned TokLen = 1) const; |
| 258 | |
| 259 | /// getSourceLocation - Return a source location for the next character in |
| 260 | /// the current file. |
| 261 | SourceLocation getSourceLocation() override { |
| 262 | return getSourceLocation(BufferPtr); |
| 263 | } |
| 264 | |
| 265 | /// Return the current location in the buffer. |
| 266 | const char *getBufferLocation() const { return BufferPtr; } |
| 267 | |
| 268 | /// Stringify - Convert the specified string into a C string by i) escaping |
| 269 | /// '\\' and " characters and ii) replacing newline character(s) with "\\n". |
| 270 | /// If Charify is true, this escapes the ' character instead of ". |
| 271 | static std::string Stringify(StringRef Str, bool Charify = false); |
| 272 | |
| 273 | /// Stringify - Convert the specified string into a C string by i) escaping |
| 274 | /// '\\' and " characters and ii) replacing newline character(s) with "\\n". |
| 275 | static void Stringify(SmallVectorImpl<char> &Str); |
| 276 | |
| 277 | /// getSpelling - This method is used to get the spelling of a token into a |
| 278 | /// preallocated buffer, instead of as an std::string. The caller is required |
| 279 | /// to allocate enough space for the token, which is guaranteed to be at least |
| 280 | /// Tok.getLength() bytes long. The length of the actual result is returned. |
| 281 | /// |
| 282 | /// Note that this method may do two possible things: it may either fill in |
| 283 | /// the buffer specified with characters, or it may *change the input pointer* |
| 284 | /// to point to a constant buffer with the data already in it (avoiding a |
| 285 | /// copy). The caller is not allowed to modify the returned buffer pointer |
| 286 | /// if an internal buffer is returned. |
| 287 | static unsigned getSpelling(const Token &Tok, const char *&Buffer, |
| 288 | const SourceManager &SourceMgr, |
| 289 | const LangOptions &LangOpts, |
| 290 | bool *Invalid = nullptr); |
| 291 | |
| 292 | /// getSpelling() - Return the 'spelling' of the Tok token. The spelling of a |
| 293 | /// token is the characters used to represent the token in the source file |
| 294 | /// after trigraph expansion and escaped-newline folding. In particular, this |
| 295 | /// wants to get the true, uncanonicalized, spelling of things like digraphs |
| 296 | /// UCNs, etc. |
| 297 | static std::string getSpelling(const Token &Tok, |
| 298 | const SourceManager &SourceMgr, |
| 299 | const LangOptions &LangOpts, |
| 300 | bool *Invalid = nullptr); |
| 301 | |
| 302 | /// getSpelling - This method is used to get the spelling of the |
| 303 | /// token at the given source location. If, as is usually true, it |
| 304 | /// is not necessary to copy any data, then the returned string may |
| 305 | /// not point into the provided buffer. |
| 306 | /// |
| 307 | /// This method lexes at the expansion depth of the given |
| 308 | /// location and does not jump to the expansion or spelling |
| 309 | /// location. |
| 310 | static StringRef getSpelling(SourceLocation loc, |
| 311 | SmallVectorImpl<char> &buffer, |
| 312 | const SourceManager &SM, |
| 313 | const LangOptions &options, |
| 314 | bool *invalid = nullptr); |
| 315 | |
| 316 | /// MeasureTokenLength - Relex the token at the specified location and return |
| 317 | /// its length in bytes in the input file. If the token needs cleaning (e.g. |
| 318 | /// includes a trigraph or an escaped newline) then this count includes bytes |
| 319 | /// that are part of that. |
| 320 | static unsigned MeasureTokenLength(SourceLocation Loc, |
| 321 | const SourceManager &SM, |
| 322 | const LangOptions &LangOpts); |
| 323 | |
| 324 | /// Relex the token at the specified location. |
| 325 | /// \returns true if there was a failure, false on success. |
| 326 | static bool getRawToken(SourceLocation Loc, Token &Result, |
| 327 | const SourceManager &SM, |
| 328 | const LangOptions &LangOpts, |
| 329 | bool IgnoreWhiteSpace = false); |
| 330 | |
| 331 | /// Given a location any where in a source buffer, find the location |
| 332 | /// that corresponds to the beginning of the token in which the original |
| 333 | /// source location lands. |
| 334 | static SourceLocation GetBeginningOfToken(SourceLocation Loc, |
| 335 | const SourceManager &SM, |
| 336 | const LangOptions &LangOpts); |
| 337 | |
| 338 | /// Get the physical length (including trigraphs and escaped newlines) of the |
| 339 | /// first \p Characters characters of the token starting at TokStart. |
| 340 | static unsigned getTokenPrefixLength(SourceLocation TokStart, |
| 341 | unsigned CharNo, |
| 342 | const SourceManager &SM, |
| 343 | const LangOptions &LangOpts); |
| 344 | |
| 345 | /// AdvanceToTokenCharacter - If the current SourceLocation specifies a |
| 346 | /// location at the start of a token, return a new location that specifies a |
| 347 | /// character within the token. This handles trigraphs and escaped newlines. |
| 348 | static SourceLocation AdvanceToTokenCharacter(SourceLocation TokStart, |
| 349 | unsigned Characters, |
| 350 | const SourceManager &SM, |
| 351 | const LangOptions &LangOpts) { |
| 352 | return TokStart.getLocWithOffset( |
| 353 | getTokenPrefixLength(TokStart, Characters, SM, LangOpts)); |
| 354 | } |
| 355 | |
| 356 | /// Computes the source location just past the end of the |
| 357 | /// token at this source location. |
| 358 | /// |
| 359 | /// This routine can be used to produce a source location that |
| 360 | /// points just past the end of the token referenced by \p Loc, and |
| 361 | /// is generally used when a diagnostic needs to point just after a |
| 362 | /// token where it expected something different that it received. If |
| 363 | /// the returned source location would not be meaningful (e.g., if |
| 364 | /// it points into a macro), this routine returns an invalid |
| 365 | /// source location. |
| 366 | /// |
| 367 | /// \param Offset an offset from the end of the token, where the source |
| 368 | /// location should refer to. The default offset (0) produces a source |
| 369 | /// location pointing just past the end of the token; an offset of 1 produces |
| 370 | /// a source location pointing to the last character in the token, etc. |
| 371 | static SourceLocation getLocForEndOfToken(SourceLocation Loc, unsigned Offset, |
| 372 | const SourceManager &SM, |
| 373 | const LangOptions &LangOpts); |
| 374 | |
| 375 | /// Given a token range, produce a corresponding CharSourceRange that |
| 376 | /// is not a token range. This allows the source range to be used by |
| 377 | /// components that don't have access to the lexer and thus can't find the |
| 378 | /// end of the range for themselves. |
| 379 | static CharSourceRange getAsCharRange(SourceRange Range, |
| 380 | const SourceManager &SM, |
| 381 | const LangOptions &LangOpts) { |
| 382 | SourceLocation End = getLocForEndOfToken(Range.getEnd(), 0, SM, LangOpts); |
| 383 | return End.isInvalid() ? CharSourceRange() |
| 384 | : CharSourceRange::getCharRange( |
| 385 | Range.getBegin(), End.getLocWithOffset(-1)); |
| 386 | } |
| 387 | static CharSourceRange getAsCharRange(CharSourceRange Range, |
| 388 | const SourceManager &SM, |
| 389 | const LangOptions &LangOpts) { |
| 390 | return Range.isTokenRange() |
| 391 | ? getAsCharRange(Range.getAsRange(), SM, LangOpts) |
| 392 | : Range; |
| 393 | } |
| 394 | |
| 395 | /// Returns true if the given MacroID location points at the first |
| 396 | /// token of the macro expansion. |
| 397 | /// |
| 398 | /// \param MacroBegin If non-null and function returns true, it is set to |
| 399 | /// begin location of the macro. |
| 400 | static bool isAtStartOfMacroExpansion(SourceLocation loc, |
| 401 | const SourceManager &SM, |
| 402 | const LangOptions &LangOpts, |
| 403 | SourceLocation *MacroBegin = nullptr); |
| 404 | |
| 405 | /// Returns true if the given MacroID location points at the last |
| 406 | /// token of the macro expansion. |
| 407 | /// |
| 408 | /// \param MacroEnd If non-null and function returns true, it is set to |
| 409 | /// end location of the macro. |
| 410 | static bool isAtEndOfMacroExpansion(SourceLocation loc, |
| 411 | const SourceManager &SM, |
| 412 | const LangOptions &LangOpts, |
| 413 | SourceLocation *MacroEnd = nullptr); |
| 414 | |
| 415 | /// Accepts a range and returns a character range with file locations. |
| 416 | /// |
| 417 | /// Returns a null range if a part of the range resides inside a macro |
| 418 | /// expansion or the range does not reside on the same FileID. |
| 419 | /// |
| 420 | /// This function is trying to deal with macros and return a range based on |
| 421 | /// file locations. The cases where it can successfully handle macros are: |
| 422 | /// |
| 423 | /// -begin or end range lies at the start or end of a macro expansion, in |
| 424 | /// which case the location will be set to the expansion point, e.g: |
| 425 | /// \#define M 1 2 |
| 426 | /// a M |
| 427 | /// If you have a range [a, 2] (where 2 came from the macro), the function |
| 428 | /// will return a range for "a M" |
| 429 | /// if you have range [a, 1], the function will fail because the range |
| 430 | /// overlaps with only a part of the macro |
| 431 | /// |
| 432 | /// -The macro is a function macro and the range can be mapped to the macro |
| 433 | /// arguments, e.g: |
| 434 | /// \#define M 1 2 |
| 435 | /// \#define FM(x) x |
| 436 | /// FM(a b M) |
| 437 | /// if you have range [b, 2], the function will return the file range "b M" |
| 438 | /// inside the macro arguments. |
| 439 | /// if you have range [a, 2], the function will return the file range |
| 440 | /// "FM(a b M)" since the range includes all of the macro expansion. |
| 441 | static CharSourceRange makeFileCharRange(CharSourceRange Range, |
| 442 | const SourceManager &SM, |
| 443 | const LangOptions &LangOpts); |
| 444 | |
| 445 | /// Returns a string for the source that the range encompasses. |
| 446 | static StringRef getSourceText(CharSourceRange Range, |
| 447 | const SourceManager &SM, |
| 448 | const LangOptions &LangOpts, |
| 449 | bool *Invalid = nullptr); |
| 450 | |
| 451 | /// Retrieve the name of the immediate macro expansion. |
| 452 | /// |
| 453 | /// This routine starts from a source location, and finds the name of the macro |
| 454 | /// responsible for its immediate expansion. It looks through any intervening |
| 455 | /// macro argument expansions to compute this. It returns a StringRef which |
| 456 | /// refers to the SourceManager-owned buffer of the source where that macro |
| 457 | /// name is spelled. Thus, the result shouldn't out-live that SourceManager. |
| 458 | static StringRef getImmediateMacroName(SourceLocation Loc, |
| 459 | const SourceManager &SM, |
| 460 | const LangOptions &LangOpts); |
| 461 | |
| 462 | /// Retrieve the name of the immediate macro expansion. |
| 463 | /// |
| 464 | /// This routine starts from a source location, and finds the name of the |
| 465 | /// macro responsible for its immediate expansion. It looks through any |
| 466 | /// intervening macro argument expansions to compute this. It returns a |
| 467 | /// StringRef which refers to the SourceManager-owned buffer of the source |
| 468 | /// where that macro name is spelled. Thus, the result shouldn't out-live |
| 469 | /// that SourceManager. |
| 470 | /// |
| 471 | /// This differs from Lexer::getImmediateMacroName in that any macro argument |
| 472 | /// location will result in the topmost function macro that accepted it. |
| 473 | /// e.g. |
| 474 | /// \code |
| 475 | /// MAC1( MAC2(foo) ) |
| 476 | /// \endcode |
| 477 | /// for location of 'foo' token, this function will return "MAC1" while |
| 478 | /// Lexer::getImmediateMacroName will return "MAC2". |
| 479 | static StringRef getImmediateMacroNameForDiagnostics( |
| 480 | SourceLocation Loc, const SourceManager &SM, const LangOptions &LangOpts); |
| 481 | |
| 482 | /// Compute the preamble of the given file. |
| 483 | /// |
| 484 | /// The preamble of a file contains the initial comments, include directives, |
| 485 | /// and other preprocessor directives that occur before the code in this |
| 486 | /// particular file actually begins. The preamble of the main source file is |
| 487 | /// a potential prefix header. |
| 488 | /// |
| 489 | /// \param Buffer The memory buffer containing the file's contents. |
| 490 | /// |
| 491 | /// \param MaxLines If non-zero, restrict the length of the preamble |
| 492 | /// to fewer than this number of lines. |
| 493 | /// |
| 494 | /// \returns The offset into the file where the preamble ends and the rest |
| 495 | /// of the file begins along with a boolean value indicating whether |
| 496 | /// the preamble ends at the beginning of a new line. |
| 497 | static PreambleBounds ComputePreamble(StringRef Buffer, |
| 498 | const LangOptions &LangOpts, |
| 499 | unsigned MaxLines = 0); |
| 500 | |
| 501 | /// Finds the token that comes right after the given location. |
| 502 | /// |
| 503 | /// Returns the next token, or none if the location is inside a macro. |
| 504 | static Optional<Token> findNextToken(SourceLocation Loc, |
| 505 | const SourceManager &SM, |
| 506 | const LangOptions &LangOpts); |
| 507 | |
| 508 | /// Checks that the given token is the first token that occurs after |
| 509 | /// the given location (this excludes comments and whitespace). Returns the |
| 510 | /// location immediately after the specified token. If the token is not found |
| 511 | /// or the location is inside a macro, the returned source location will be |
| 512 | /// invalid. |
| 513 | static SourceLocation findLocationAfterToken(SourceLocation loc, |
| 514 | tok::TokenKind TKind, |
| 515 | const SourceManager &SM, |
| 516 | const LangOptions &LangOpts, |
| 517 | bool SkipTrailingWhitespaceAndNewLine); |
| 518 | |
| 519 | /// Returns true if the given character could appear in an identifier. |
| 520 | static bool isIdentifierBodyChar(char c, const LangOptions &LangOpts); |
| 521 | |
| 522 | /// Checks whether new line pointed by Str is preceded by escape |
| 523 | /// sequence. |
| 524 | static bool isNewLineEscaped(const char *BufferStart, const char *Str); |
| 525 | |
| 526 | /// getCharAndSizeNoWarn - Like the getCharAndSize method, but does not ever |
| 527 | /// emit a warning. |
| 528 | static inline char getCharAndSizeNoWarn(const char *Ptr, unsigned &Size, |
| 529 | const LangOptions &LangOpts) { |
| 530 | // If this is not a trigraph and not a UCN or escaped newline, return |
| 531 | // quickly. |
| 532 | if (isObviouslySimpleCharacter(Ptr[0])) { |
| 533 | Size = 1; |
| 534 | return *Ptr; |
| 535 | } |
| 536 | |
| 537 | Size = 0; |
| 538 | return getCharAndSizeSlowNoWarn(Ptr, Size, LangOpts); |
| 539 | } |
| 540 | |
| 541 | /// Returns the leading whitespace for line that corresponds to the given |
| 542 | /// location \p Loc. |
| 543 | static StringRef getIndentationForLine(SourceLocation Loc, |
| 544 | const SourceManager &SM); |
| 545 | |
| 546 | private: |
| 547 | //===--------------------------------------------------------------------===// |
| 548 | // Internal implementation interfaces. |
| 549 | |
| 550 | /// LexTokenInternal - Internal interface to lex a preprocessing token. Called |
| 551 | /// by Lex. |
| 552 | /// |
| 553 | bool LexTokenInternal(Token &Result, bool TokAtPhysicalStartOfLine); |
| 554 | |
| 555 | bool CheckUnicodeWhitespace(Token &Result, uint32_t C, const char *CurPtr); |
| 556 | |
| 557 | /// Given that a token begins with the Unicode character \p C, figure out |
| 558 | /// what kind of token it is and dispatch to the appropriate lexing helper |
| 559 | /// function. |
| 560 | bool LexUnicode(Token &Result, uint32_t C, const char *CurPtr); |
| 561 | |
| 562 | /// FormTokenWithChars - When we lex a token, we have identified a span |
| 563 | /// starting at BufferPtr, going to TokEnd that forms the token. This method |
| 564 | /// takes that range and assigns it to the token as its location and size. In |
| 565 | /// addition, since tokens cannot overlap, this also updates BufferPtr to be |
| 566 | /// TokEnd. |
| 567 | void FormTokenWithChars(Token &Result, const char *TokEnd, |
| 568 | tok::TokenKind Kind) { |
| 569 | unsigned TokLen = TokEnd-BufferPtr; |
| 570 | Result.setLength(TokLen); |
| 571 | Result.setLocation(getSourceLocation(BufferPtr, TokLen)); |
| 572 | Result.setKind(Kind); |
| 573 | BufferPtr = TokEnd; |
| 574 | } |
| 575 | |
| 576 | /// isNextPPTokenLParen - Return 1 if the next unexpanded token will return a |
| 577 | /// tok::l_paren token, 0 if it is something else and 2 if there are no more |
| 578 | /// tokens in the buffer controlled by this lexer. |
| 579 | unsigned isNextPPTokenLParen(); |
| 580 | |
| 581 | //===--------------------------------------------------------------------===// |
| 582 | // Lexer character reading interfaces. |
| 583 | |
| 584 | // This lexer is built on two interfaces for reading characters, both of which |
| 585 | // automatically provide phase 1/2 translation. getAndAdvanceChar is used |
| 586 | // when we know that we will be reading a character from the input buffer and |
| 587 | // that this character will be part of the result token. This occurs in (f.e.) |
| 588 | // string processing, because we know we need to read until we find the |
| 589 | // closing '"' character. |
| 590 | // |
| 591 | // The second interface is the combination of getCharAndSize with |
| 592 | // ConsumeChar. getCharAndSize reads a phase 1/2 translated character, |
| 593 | // returning it and its size. If the lexer decides that this character is |
| 594 | // part of the current token, it calls ConsumeChar on it. This two stage |
| 595 | // approach allows us to emit diagnostics for characters (e.g. warnings about |
| 596 | // trigraphs), knowing that they only are emitted if the character is |
| 597 | // consumed. |
| 598 | |
| 599 | /// isObviouslySimpleCharacter - Return true if the specified character is |
| 600 | /// obviously the same in translation phase 1 and translation phase 3. This |
| 601 | /// can return false for characters that end up being the same, but it will |
| 602 | /// never return true for something that needs to be mapped. |
| 603 | static bool isObviouslySimpleCharacter(char C) { |
| 604 | return C != '?' && C != '\\'; |
| 605 | } |
| 606 | |
| 607 | /// getAndAdvanceChar - Read a single 'character' from the specified buffer, |
| 608 | /// advance over it, and return it. This is tricky in several cases. Here we |
| 609 | /// just handle the trivial case and fall-back to the non-inlined |
| 610 | /// getCharAndSizeSlow method to handle the hard case. |
| 611 | inline char getAndAdvanceChar(const char *&Ptr, Token &Tok) { |
| 612 | // If this is not a trigraph and not a UCN or escaped newline, return |
| 613 | // quickly. |
| 614 | if (isObviouslySimpleCharacter(Ptr[0])) return *Ptr++; |
| 615 | |
| 616 | unsigned Size = 0; |
| 617 | char C = getCharAndSizeSlow(Ptr, Size, &Tok); |
| 618 | Ptr += Size; |
| 619 | return C; |
| 620 | } |
| 621 | |
| 622 | /// ConsumeChar - When a character (identified by getCharAndSize) is consumed |
| 623 | /// and added to a given token, check to see if there are diagnostics that |
| 624 | /// need to be emitted or flags that need to be set on the token. If so, do |
| 625 | /// it. |
| 626 | const char *ConsumeChar(const char *Ptr, unsigned Size, Token &Tok) { |
| 627 | // Normal case, we consumed exactly one token. Just return it. |
| 628 | if (Size == 1) |
| 629 | return Ptr+Size; |
| 630 | |
| 631 | // Otherwise, re-lex the character with a current token, allowing |
| 632 | // diagnostics to be emitted and flags to be set. |
| 633 | Size = 0; |
| 634 | getCharAndSizeSlow(Ptr, Size, &Tok); |
| 635 | return Ptr+Size; |
| 636 | } |
| 637 | |
| 638 | /// getCharAndSize - Peek a single 'character' from the specified buffer, |
| 639 | /// get its size, and return it. This is tricky in several cases. Here we |
| 640 | /// just handle the trivial case and fall-back to the non-inlined |
| 641 | /// getCharAndSizeSlow method to handle the hard case. |
| 642 | inline char getCharAndSize(const char *Ptr, unsigned &Size) { |
| 643 | // If this is not a trigraph and not a UCN or escaped newline, return |
| 644 | // quickly. |
| 645 | if (isObviouslySimpleCharacter(Ptr[0])) { |
| 646 | Size = 1; |
| 647 | return *Ptr; |
| 648 | } |
| 649 | |
| 650 | Size = 0; |
| 651 | return getCharAndSizeSlow(Ptr, Size); |
| 652 | } |
| 653 | |
| 654 | /// getCharAndSizeSlow - Handle the slow/uncommon case of the getCharAndSize |
| 655 | /// method. |
| 656 | char getCharAndSizeSlow(const char *Ptr, unsigned &Size, |
| 657 | Token *Tok = nullptr); |
| 658 | |
| 659 | /// getEscapedNewLineSize - Return the size of the specified escaped newline, |
| 660 | /// or 0 if it is not an escaped newline. P[-1] is known to be a "\" on entry |
| 661 | /// to this function. |
| 662 | static unsigned getEscapedNewLineSize(const char *P); |
| 663 | |
| 664 | /// SkipEscapedNewLines - If P points to an escaped newline (or a series of |
| 665 | /// them), skip over them and return the first non-escaped-newline found, |
| 666 | /// otherwise return P. |
| 667 | static const char *SkipEscapedNewLines(const char *P); |
| 668 | |
| 669 | /// getCharAndSizeSlowNoWarn - Same as getCharAndSizeSlow, but never emits a |
| 670 | /// diagnostic. |
| 671 | static char getCharAndSizeSlowNoWarn(const char *Ptr, unsigned &Size, |
| 672 | const LangOptions &LangOpts); |
| 673 | |
| 674 | //===--------------------------------------------------------------------===// |
| 675 | // Other lexer functions. |
| 676 | |
| 677 | void SetByteOffset(unsigned Offset, bool StartOfLine); |
| 678 | |
| 679 | void PropagateLineStartLeadingSpaceInfo(Token &Result); |
| 680 | |
| 681 | const char *LexUDSuffix(Token &Result, const char *CurPtr, |
| 682 | bool IsStringLiteral); |
| 683 | |
| 684 | // Helper functions to lex the remainder of a token of the specific type. |
| 685 | bool LexIdentifier (Token &Result, const char *CurPtr); |
| 686 | bool LexNumericConstant (Token &Result, const char *CurPtr); |
| 687 | bool LexStringLiteral (Token &Result, const char *CurPtr, |
| 688 | tok::TokenKind Kind); |
| 689 | bool LexRawStringLiteral (Token &Result, const char *CurPtr, |
| 690 | tok::TokenKind Kind); |
| 691 | bool LexAngledStringLiteral(Token &Result, const char *CurPtr); |
| 692 | bool LexCharConstant (Token &Result, const char *CurPtr, |
| 693 | tok::TokenKind Kind); |
| 694 | bool LexEndOfFile (Token &Result, const char *CurPtr); |
| 695 | bool SkipWhitespace (Token &Result, const char *CurPtr, |
| 696 | bool &TokAtPhysicalStartOfLine); |
| 697 | bool SkipLineComment (Token &Result, const char *CurPtr, |
| 698 | bool &TokAtPhysicalStartOfLine); |
| 699 | bool SkipBlockComment (Token &Result, const char *CurPtr, |
| 700 | bool &TokAtPhysicalStartOfLine); |
| 701 | bool SaveLineComment (Token &Result, const char *CurPtr); |
| 702 | |
| 703 | bool IsStartOfConflictMarker(const char *CurPtr); |
| 704 | bool HandleEndOfConflictMarker(const char *CurPtr); |
| 705 | |
| 706 | bool lexEditorPlaceholder(Token &Result, const char *CurPtr); |
| 707 | |
| 708 | bool isCodeCompletionPoint(const char *CurPtr) const; |
| 709 | void cutOffLexing() { BufferPtr = BufferEnd; } |
| 710 | |
| 711 | bool isHexaLiteral(const char *Start, const LangOptions &LangOpts); |
| 712 | |
| 713 | void codeCompleteIncludedFile(const char *PathStart, |
| 714 | const char *CompletionPoint, bool IsAngled); |
| 715 | |
| 716 | /// Read a universal character name. |
| 717 | /// |
| 718 | /// \param StartPtr The position in the source buffer after the initial '\'. |
| 719 | /// If the UCN is syntactically well-formed (but not |
| 720 | /// necessarily valid), this parameter will be updated to |
| 721 | /// point to the character after the UCN. |
| 722 | /// \param SlashLoc The position in the source buffer of the '\'. |
| 723 | /// \param Result The token being formed. Pass \c nullptr to suppress |
| 724 | /// diagnostics and handle token formation in the caller. |
| 725 | /// |
| 726 | /// \return The Unicode codepoint specified by the UCN, or 0 if the UCN is |
| 727 | /// invalid. |
| 728 | uint32_t tryReadUCN(const char *&StartPtr, const char *SlashLoc, Token *Result); |
| 729 | |
| 730 | /// Try to consume a UCN as part of an identifier at the current |
| 731 | /// location. |
| 732 | /// \param CurPtr Initially points to the range of characters in the source |
| 733 | /// buffer containing the '\'. Updated to point past the end of |
| 734 | /// the UCN on success. |
| 735 | /// \param Size The number of characters occupied by the '\' (including |
| 736 | /// trigraphs and escaped newlines). |
| 737 | /// \param Result The token being produced. Marked as containing a UCN on |
| 738 | /// success. |
| 739 | /// \return \c true if a UCN was lexed and it produced an acceptable |
| 740 | /// identifier character, \c false otherwise. |
| 741 | bool tryConsumeIdentifierUCN(const char *&CurPtr, unsigned Size, |
| 742 | Token &Result); |
| 743 | |
| 744 | /// Try to consume an identifier character encoded in UTF-8. |
| 745 | /// \param CurPtr Points to the start of the (potential) UTF-8 code unit |
| 746 | /// sequence. On success, updated to point past the end of it. |
| 747 | /// \return \c true if a UTF-8 sequence mapping to an acceptable identifier |
| 748 | /// character was lexed, \c false otherwise. |
| 749 | bool tryConsumeIdentifierUTF8Char(const char *&CurPtr); |
| 750 | }; |
| 751 | |
| 752 | } // namespace clang |
| 753 | |
| 754 | #endif // LLVM_CLANG_LEX_LEXER_H |
| 755 |