| //===- Lexer.h - C Language Family Lexer ------------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file defines the Lexer interface. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_CLANG_LEX_LEXER_H |
| #define LLVM_CLANG_LEX_LEXER_H |
| |
| #include "clang/Basic/LangOptions.h" |
| #include "clang/Basic/SourceLocation.h" |
| #include "clang/Basic/TokenKinds.h" |
| #include "clang/Lex/PreprocessorLexer.h" |
| #include "clang/Lex/Token.h" |
| #include "llvm/ADT/Optional.h" |
| #include "llvm/ADT/SmallVector.h" |
| #include "llvm/ADT/StringRef.h" |
| #include <cassert> |
| #include <cstdint> |
| #include <string> |
| |
| namespace llvm { |
| |
| class MemoryBuffer; |
| |
| } // namespace llvm |
| |
| namespace clang { |
| |
| class DiagnosticBuilder; |
| class Preprocessor; |
| class SourceManager; |
| |
| /// ConflictMarkerKind - Kinds of conflict marker which the lexer might be |
| /// recovering from. |
| enum ConflictMarkerKind { |
| /// Not within a conflict marker. |
| CMK_None, |
| |
| /// A normal or diff3 conflict marker, initiated by at least 7 "<"s, |
| /// separated by at least 7 "="s or "|"s, and terminated by at least 7 ">"s. |
| CMK_Normal, |
| |
| /// A Perforce-style conflict marker, initiated by 4 ">"s, |
| /// separated by 4 "="s, and terminated by 4 "<"s. |
| CMK_Perforce |
| }; |
| |
| /// Describes the bounds (start, size) of the preamble and a flag required by |
| /// PreprocessorOptions::PrecompiledPreambleBytes. |
| /// The preamble includes the BOM, if any. |
| struct PreambleBounds { |
| /// Size of the preamble in bytes. |
| unsigned Size; |
| |
| /// Whether the preamble ends at the start of a new line. |
| /// |
| /// Used to inform the lexer as to whether it's starting at the beginning of |
| /// a line after skipping the preamble. |
| bool PreambleEndsAtStartOfLine; |
| |
| PreambleBounds(unsigned Size, bool PreambleEndsAtStartOfLine) |
| : Size(Size), PreambleEndsAtStartOfLine(PreambleEndsAtStartOfLine) {} |
| }; |
| |
| /// Lexer - This provides a simple interface that turns a text buffer into a |
| /// stream of tokens. This provides no support for file reading or buffering, |
| /// or buffering/seeking of tokens, only forward lexing is supported. It relies |
| /// on the specified Preprocessor object to handle preprocessor directives, etc. |
| class Lexer : public PreprocessorLexer { |
| friend class Preprocessor; |
| |
| void anchor() override; |
| |
| //===--------------------------------------------------------------------===// |
| // Constant configuration values for this lexer. |
| |
| // Start of the buffer. |
| const char *BufferStart; |
| |
| // End of the buffer. |
| const char *BufferEnd; |
| |
| // Location for start of file. |
| SourceLocation FileLoc; |
| |
| // LangOpts enabled by this language (cache). |
| LangOptions LangOpts; |
| |
| // True if lexer for _Pragma handling. |
| bool Is_PragmaLexer; |
| |
| //===--------------------------------------------------------------------===// |
| // Context-specific lexing flags set by the preprocessor. |
| // |
| |
| /// ExtendedTokenMode - The lexer can optionally keep comments and whitespace |
| /// and return them as tokens. This is used for -C and -CC modes, and |
| /// whitespace preservation can be useful for some clients that want to lex |
| /// the file in raw mode and get every character from the file. |
| /// |
| /// When this is set to 2 it returns comments and whitespace. When set to 1 |
| /// it returns comments, when it is set to 0 it returns normal tokens only. |
| unsigned char ExtendedTokenMode; |
| |
| //===--------------------------------------------------------------------===// |
| // Context that changes as the file is lexed. |
| // NOTE: any state that mutates when in raw mode must have save/restore code |
| // in Lexer::isNextPPTokenLParen. |
| |
| // BufferPtr - Current pointer into the buffer. This is the next character |
| // to be lexed. |
| const char *BufferPtr; |
| |
| // IsAtStartOfLine - True if the next lexed token should get the "start of |
| // line" flag set on it. |
| bool IsAtStartOfLine; |
| |
| bool IsAtPhysicalStartOfLine; |
| |
| bool HasLeadingSpace; |
| |
| bool HasLeadingEmptyMacro; |
| |
| // CurrentConflictMarkerState - The kind of conflict marker we are handling. |
| ConflictMarkerKind CurrentConflictMarkerState; |
| |
| void InitLexer(const char *BufStart, const char *BufPtr, const char *BufEnd); |
| |
| public: |
| /// Lexer constructor - Create a new lexer object for the specified buffer |
| /// with the specified preprocessor managing the lexing process. This lexer |
| /// assumes that the associated file buffer and Preprocessor objects will |
| /// outlive it, so it doesn't take ownership of either of them. |
| Lexer(FileID FID, const llvm::MemoryBuffer *InputBuffer, Preprocessor &PP); |
| |
| /// Lexer constructor - Create a new raw lexer object. This object is only |
| /// suitable for calls to 'LexFromRawLexer'. This lexer assumes that the |
| /// text range will outlive it, so it doesn't take ownership of it. |
| Lexer(SourceLocation FileLoc, const LangOptions &LangOpts, |
| const char *BufStart, const char *BufPtr, const char *BufEnd); |
| |
| /// Lexer constructor - Create a new raw lexer object. This object is only |
| /// suitable for calls to 'LexFromRawLexer'. This lexer assumes that the |
| /// text range will outlive it, so it doesn't take ownership of it. |
| Lexer(FileID FID, const llvm::MemoryBuffer *InputBuffer, |
| const SourceManager &SM, const LangOptions &LangOpts); |
| |
| Lexer(const Lexer &) = delete; |
| Lexer &operator=(const Lexer &) = delete; |
| |
| /// Create_PragmaLexer: Lexer constructor - Create a new lexer object for |
| /// _Pragma expansion. This has a variety of magic semantics that this method |
| /// sets up. It returns a new'd Lexer that must be delete'd when done. |
| static Lexer *Create_PragmaLexer(SourceLocation SpellingLoc, |
| SourceLocation ExpansionLocStart, |
| SourceLocation ExpansionLocEnd, |
| unsigned TokLen, Preprocessor &PP); |
| |
| /// getLangOpts - Return the language features currently enabled. |
| /// NOTE: this lexer modifies features as a file is parsed! |
| const LangOptions &getLangOpts() const { return LangOpts; } |
| |
| /// getFileLoc - Return the File Location for the file we are lexing out of. |
| /// The physical location encodes the location where the characters come from, |
| /// the virtual location encodes where we should *claim* the characters came |
| /// from. Currently this is only used by _Pragma handling. |
| SourceLocation getFileLoc() const { return FileLoc; } |
| |
| private: |
| /// Lex - Return the next token in the file. If this is the end of file, it |
| /// return the tok::eof token. This implicitly involves the preprocessor. |
| bool Lex(Token &Result); |
| |
| public: |
| /// isPragmaLexer - Returns true if this Lexer is being used to lex a pragma. |
| bool isPragmaLexer() const { return Is_PragmaLexer; } |
| |
| private: |
| /// IndirectLex - An indirect call to 'Lex' that can be invoked via |
| /// the PreprocessorLexer interface. |
| void IndirectLex(Token &Result) override { Lex(Result); } |
| |
| public: |
| /// LexFromRawLexer - Lex a token from a designated raw lexer (one with no |
| /// associated preprocessor object. Return true if the 'next character to |
| /// read' pointer points at the end of the lexer buffer, false otherwise. |
| bool LexFromRawLexer(Token &Result) { |
| assert(LexingRawMode && "Not already in raw mode!"); |
| Lex(Result); |
| // Note that lexing to the end of the buffer doesn't implicitly delete the |
| // lexer when in raw mode. |
| return BufferPtr == BufferEnd; |
| } |
| |
| /// isKeepWhitespaceMode - Return true if the lexer should return tokens for |
| /// every character in the file, including whitespace and comments. This |
| /// should only be used in raw mode, as the preprocessor is not prepared to |
| /// deal with the excess tokens. |
| bool isKeepWhitespaceMode() const { |
| return ExtendedTokenMode > 1; |
| } |
| |
| /// SetKeepWhitespaceMode - This method lets clients enable or disable |
| /// whitespace retention mode. |
| void SetKeepWhitespaceMode(bool Val) { |
| assert((!Val || LexingRawMode || LangOpts.TraditionalCPP) && |
| "Can only retain whitespace in raw mode or -traditional-cpp"); |
| ExtendedTokenMode = Val ? 2 : 0; |
| } |
| |
| /// inKeepCommentMode - Return true if the lexer should return comments as |
| /// tokens. |
| bool inKeepCommentMode() const { |
| return ExtendedTokenMode > 0; |
| } |
| |
| /// SetCommentRetentionMode - Change the comment retention mode of the lexer |
| /// to the specified mode. This is really only useful when lexing in raw |
| /// mode, because otherwise the lexer needs to manage this. |
| void SetCommentRetentionState(bool Mode) { |
| assert(!isKeepWhitespaceMode() && |
| "Can't play with comment retention state when retaining whitespace"); |
| ExtendedTokenMode = Mode ? 1 : 0; |
| } |
| |
| /// Sets the extended token mode back to its initial value, according to the |
| /// language options and preprocessor. This controls whether the lexer |
| /// produces comment and whitespace tokens. |
| /// |
| /// This requires the lexer to have an associated preprocessor. A standalone |
| /// lexer has nothing to reset to. |
| void resetExtendedTokenMode(); |
| |
| /// Gets source code buffer. |
| StringRef getBuffer() const { |
| return StringRef(BufferStart, BufferEnd - BufferStart); |
| } |
| |
| /// ReadToEndOfLine - Read the rest of the current preprocessor line as an |
| /// uninterpreted string. This switches the lexer out of directive mode. |
| void ReadToEndOfLine(SmallVectorImpl<char> *Result = nullptr); |
| |
| |
| /// Diag - Forwarding function for diagnostics. This translate a source |
| /// position in the current buffer into a SourceLocation object for rendering. |
| DiagnosticBuilder Diag(const char *Loc, unsigned DiagID) const; |
| |
| /// getSourceLocation - Return a source location identifier for the specified |
| /// offset in the current file. |
| SourceLocation getSourceLocation(const char *Loc, unsigned TokLen = 1) const; |
| |
| /// getSourceLocation - Return a source location for the next character in |
| /// the current file. |
| SourceLocation getSourceLocation() override { |
| return getSourceLocation(BufferPtr); |
| } |
| |
| /// Return the current location in the buffer. |
| const char *getBufferLocation() const { return BufferPtr; } |
| |
| /// Stringify - Convert the specified string into a C string by i) escaping |
| /// '\\' and " characters and ii) replacing newline character(s) with "\\n". |
| /// If Charify is true, this escapes the ' character instead of ". |
| static std::string Stringify(StringRef Str, bool Charify = false); |
| |
| /// Stringify - Convert the specified string into a C string by i) escaping |
| /// '\\' and " characters and ii) replacing newline character(s) with "\\n". |
| static void Stringify(SmallVectorImpl<char> &Str); |
| |
| /// getSpelling - This method is used to get the spelling of a token into a |
| /// preallocated buffer, instead of as an std::string. The caller is required |
| /// to allocate enough space for the token, which is guaranteed to be at least |
| /// Tok.getLength() bytes long. The length of the actual result is returned. |
| /// |
| /// Note that this method may do two possible things: it may either fill in |
| /// the buffer specified with characters, or it may *change the input pointer* |
| /// to point to a constant buffer with the data already in it (avoiding a |
| /// copy). The caller is not allowed to modify the returned buffer pointer |
| /// if an internal buffer is returned. |
| static unsigned getSpelling(const Token &Tok, const char *&Buffer, |
| const SourceManager &SourceMgr, |
| const LangOptions &LangOpts, |
| bool *Invalid = nullptr); |
| |
| /// getSpelling() - Return the 'spelling' of the Tok token. The spelling of a |
| /// token is the characters used to represent the token in the source file |
| /// after trigraph expansion and escaped-newline folding. In particular, this |
| /// wants to get the true, uncanonicalized, spelling of things like digraphs |
| /// UCNs, etc. |
| static std::string getSpelling(const Token &Tok, |
| const SourceManager &SourceMgr, |
| const LangOptions &LangOpts, |
| bool *Invalid = nullptr); |
| |
| /// getSpelling - This method is used to get the spelling of the |
| /// token at the given source location. If, as is usually true, it |
| /// is not necessary to copy any data, then the returned string may |
| /// not point into the provided buffer. |
| /// |
| /// This method lexes at the expansion depth of the given |
| /// location and does not jump to the expansion or spelling |
| /// location. |
| static StringRef getSpelling(SourceLocation loc, |
| SmallVectorImpl<char> &buffer, |
| const SourceManager &SourceMgr, |
| const LangOptions &LangOpts, |
| bool *invalid = nullptr); |
| |
| /// MeasureTokenLength - Relex the token at the specified location and return |
| /// its length in bytes in the input file. If the token needs cleaning (e.g. |
| /// includes a trigraph or an escaped newline) then this count includes bytes |
| /// that are part of that. |
| static unsigned MeasureTokenLength(SourceLocation Loc, |
| const SourceManager &SM, |
| const LangOptions &LangOpts); |
| |
| /// Relex the token at the specified location. |
| /// \returns true if there was a failure, false on success. |
| static bool getRawToken(SourceLocation Loc, Token &Result, |
| const SourceManager &SM, |
| const LangOptions &LangOpts, |
| bool IgnoreWhiteSpace = false); |
| |
| /// Given a location any where in a source buffer, find the location |
| /// that corresponds to the beginning of the token in which the original |
| /// source location lands. |
| static SourceLocation GetBeginningOfToken(SourceLocation Loc, |
| const SourceManager &SM, |
| const LangOptions &LangOpts); |
| |
| /// Get the physical length (including trigraphs and escaped newlines) of the |
| /// first \p Characters characters of the token starting at TokStart. |
| static unsigned getTokenPrefixLength(SourceLocation TokStart, |
| unsigned Characters, |
| const SourceManager &SM, |
| const LangOptions &LangOpts); |
| |
| /// AdvanceToTokenCharacter - If the current SourceLocation specifies a |
| /// location at the start of a token, return a new location that specifies a |
| /// character within the token. This handles trigraphs and escaped newlines. |
| static SourceLocation AdvanceToTokenCharacter(SourceLocation TokStart, |
| unsigned Characters, |
| const SourceManager &SM, |
| const LangOptions &LangOpts) { |
| return TokStart.getLocWithOffset( |
| getTokenPrefixLength(TokStart, Characters, SM, LangOpts)); |
| } |
| |
| /// Computes the source location just past the end of the |
| /// token at this source location. |
| /// |
| /// This routine can be used to produce a source location that |
| /// points just past the end of the token referenced by \p Loc, and |
| /// is generally used when a diagnostic needs to point just after a |
| /// token where it expected something different that it received. If |
| /// the returned source location would not be meaningful (e.g., if |
| /// it points into a macro), this routine returns an invalid |
| /// source location. |
| /// |
| /// \param Offset an offset from the end of the token, where the source |
| /// location should refer to. The default offset (0) produces a source |
| /// location pointing just past the end of the token; an offset of 1 produces |
| /// a source location pointing to the last character in the token, etc. |
| static SourceLocation getLocForEndOfToken(SourceLocation Loc, unsigned Offset, |
| const SourceManager &SM, |
| const LangOptions &LangOpts); |
| |
| /// Given a token range, produce a corresponding CharSourceRange that |
| /// is not a token range. This allows the source range to be used by |
| /// components that don't have access to the lexer and thus can't find the |
| /// end of the range for themselves. |
| static CharSourceRange getAsCharRange(SourceRange Range, |
| const SourceManager &SM, |
| const LangOptions &LangOpts) { |
| SourceLocation End = getLocForEndOfToken(Range.getEnd(), 0, SM, LangOpts); |
| return End.isInvalid() ? CharSourceRange() |
| : CharSourceRange::getCharRange( |
| Range.getBegin(), End.getLocWithOffset(-1)); |
| } |
| static CharSourceRange getAsCharRange(CharSourceRange Range, |
| const SourceManager &SM, |
| const LangOptions &LangOpts) { |
| return Range.isTokenRange() |
| ? getAsCharRange(Range.getAsRange(), SM, LangOpts) |
| : Range; |
| } |
| |
| /// Returns true if the given MacroID location points at the first |
| /// token of the macro expansion. |
| /// |
| /// \param MacroBegin If non-null and function returns true, it is set to |
| /// begin location of the macro. |
| static bool isAtStartOfMacroExpansion(SourceLocation loc, |
| const SourceManager &SM, |
| const LangOptions &LangOpts, |
| SourceLocation *MacroBegin = nullptr); |
| |
| /// Returns true if the given MacroID location points at the last |
| /// token of the macro expansion. |
| /// |
| /// \param MacroEnd If non-null and function returns true, it is set to |
| /// end location of the macro. |
| static bool isAtEndOfMacroExpansion(SourceLocation loc, |
| const SourceManager &SM, |
| const LangOptions &LangOpts, |
| SourceLocation *MacroEnd = nullptr); |
| |
| /// Accepts a range and returns a character range with file locations. |
| /// |
| /// Returns a null range if a part of the range resides inside a macro |
| /// expansion or the range does not reside on the same FileID. |
| /// |
| /// This function is trying to deal with macros and return a range based on |
| /// file locations. The cases where it can successfully handle macros are: |
| /// |
| /// -begin or end range lies at the start or end of a macro expansion, in |
| /// which case the location will be set to the expansion point, e.g: |
| /// \#define M 1 2 |
| /// a M |
| /// If you have a range [a, 2] (where 2 came from the macro), the function |
| /// will return a range for "a M" |
| /// if you have range [a, 1], the function will fail because the range |
| /// overlaps with only a part of the macro |
| /// |
| /// -The macro is a function macro and the range can be mapped to the macro |
| /// arguments, e.g: |
| /// \#define M 1 2 |
| /// \#define FM(x) x |
| /// FM(a b M) |
| /// if you have range [b, 2], the function will return the file range "b M" |
| /// inside the macro arguments. |
| /// if you have range [a, 2], the function will return the file range |
| /// "FM(a b M)" since the range includes all of the macro expansion. |
| static CharSourceRange makeFileCharRange(CharSourceRange Range, |
| const SourceManager &SM, |
| const LangOptions &LangOpts); |
| |
| /// Returns a string for the source that the range encompasses. |
| static StringRef getSourceText(CharSourceRange Range, |
| const SourceManager &SM, |
| const LangOptions &LangOpts, |
| bool *Invalid = nullptr); |
| |
| /// Retrieve the name of the immediate macro expansion. |
| /// |
| /// This routine starts from a source location, and finds the name of the macro |
| /// responsible for its immediate expansion. It looks through any intervening |
| /// macro argument expansions to compute this. It returns a StringRef which |
| /// refers to the SourceManager-owned buffer of the source where that macro |
| /// name is spelled. Thus, the result shouldn't out-live that SourceManager. |
| static StringRef getImmediateMacroName(SourceLocation Loc, |
| const SourceManager &SM, |
| const LangOptions &LangOpts); |
| |
| /// Retrieve the name of the immediate macro expansion. |
| /// |
| /// This routine starts from a source location, and finds the name of the |
| /// macro responsible for its immediate expansion. It looks through any |
| /// intervening macro argument expansions to compute this. It returns a |
| /// StringRef which refers to the SourceManager-owned buffer of the source |
| /// where that macro name is spelled. Thus, the result shouldn't out-live |
| /// that SourceManager. |
| /// |
| /// This differs from Lexer::getImmediateMacroName in that any macro argument |
| /// location will result in the topmost function macro that accepted it. |
| /// e.g. |
| /// \code |
| /// MAC1( MAC2(foo) ) |
| /// \endcode |
| /// for location of 'foo' token, this function will return "MAC1" while |
| /// Lexer::getImmediateMacroName will return "MAC2". |
| static StringRef getImmediateMacroNameForDiagnostics( |
| SourceLocation Loc, const SourceManager &SM, const LangOptions &LangOpts); |
| |
| /// Compute the preamble of the given file. |
| /// |
| /// The preamble of a file contains the initial comments, include directives, |
| /// and other preprocessor directives that occur before the code in this |
| /// particular file actually begins. The preamble of the main source file is |
| /// a potential prefix header. |
| /// |
| /// \param Buffer The memory buffer containing the file's contents. |
| /// |
| /// \param MaxLines If non-zero, restrict the length of the preamble |
| /// to fewer than this number of lines. |
| /// |
| /// \returns The offset into the file where the preamble ends and the rest |
| /// of the file begins along with a boolean value indicating whether |
| /// the preamble ends at the beginning of a new line. |
| static PreambleBounds ComputePreamble(StringRef Buffer, |
| const LangOptions &LangOpts, |
| unsigned MaxLines = 0); |
| |
| /// Finds the token that comes right after the given location. |
| /// |
| /// Returns the next token, or none if the location is inside a macro. |
| static Optional<Token> findNextToken(SourceLocation Loc, |
| const SourceManager &SM, |
| const LangOptions &LangOpts); |
| |
| /// Checks that the given token is the first token that occurs after |
| /// the given location (this excludes comments and whitespace). Returns the |
| /// location immediately after the specified token. If the token is not found |
| /// or the location is inside a macro, the returned source location will be |
| /// invalid. |
| static SourceLocation findLocationAfterToken(SourceLocation loc, |
| tok::TokenKind TKind, |
| const SourceManager &SM, |
| const LangOptions &LangOpts, |
| bool SkipTrailingWhitespaceAndNewLine); |
| |
| /// Returns true if the given character could appear in an identifier. |
| static bool isIdentifierBodyChar(char c, const LangOptions &LangOpts); |
| |
| /// Checks whether new line pointed by Str is preceded by escape |
| /// sequence. |
| static bool isNewLineEscaped(const char *BufferStart, const char *Str); |
| |
| /// getCharAndSizeNoWarn - Like the getCharAndSize method, but does not ever |
| /// emit a warning. |
| static inline char getCharAndSizeNoWarn(const char *Ptr, unsigned &Size, |
| const LangOptions &LangOpts) { |
| // If this is not a trigraph and not a UCN or escaped newline, return |
| // quickly. |
| if (isObviouslySimpleCharacter(Ptr[0])) { |
| Size = 1; |
| return *Ptr; |
| } |
| |
| Size = 0; |
| return getCharAndSizeSlowNoWarn(Ptr, Size, LangOpts); |
| } |
| |
| /// Returns the leading whitespace for line that corresponds to the given |
| /// location \p Loc. |
| static StringRef getIndentationForLine(SourceLocation Loc, |
| const SourceManager &SM); |
| |
| private: |
| //===--------------------------------------------------------------------===// |
| // Internal implementation interfaces. |
| |
| /// LexTokenInternal - Internal interface to lex a preprocessing token. Called |
| /// by Lex. |
| /// |
| bool LexTokenInternal(Token &Result, bool TokAtPhysicalStartOfLine); |
| |
| bool CheckUnicodeWhitespace(Token &Result, uint32_t C, const char *CurPtr); |
| |
| /// Given that a token begins with the Unicode character \p C, figure out |
| /// what kind of token it is and dispatch to the appropriate lexing helper |
| /// function. |
| bool LexUnicode(Token &Result, uint32_t C, const char *CurPtr); |
| |
| /// FormTokenWithChars - When we lex a token, we have identified a span |
| /// starting at BufferPtr, going to TokEnd that forms the token. This method |
| /// takes that range and assigns it to the token as its location and size. In |
| /// addition, since tokens cannot overlap, this also updates BufferPtr to be |
| /// TokEnd. |
| void FormTokenWithChars(Token &Result, const char *TokEnd, |
| tok::TokenKind Kind) { |
| unsigned TokLen = TokEnd-BufferPtr; |
| Result.setLength(TokLen); |
| Result.setLocation(getSourceLocation(BufferPtr, TokLen)); |
| Result.setKind(Kind); |
| BufferPtr = TokEnd; |
| } |
| |
| /// isNextPPTokenLParen - Return 1 if the next unexpanded token will return a |
| /// tok::l_paren token, 0 if it is something else and 2 if there are no more |
| /// tokens in the buffer controlled by this lexer. |
| unsigned isNextPPTokenLParen(); |
| |
| //===--------------------------------------------------------------------===// |
| // Lexer character reading interfaces. |
| |
| // This lexer is built on two interfaces for reading characters, both of which |
| // automatically provide phase 1/2 translation. getAndAdvanceChar is used |
| // when we know that we will be reading a character from the input buffer and |
| // that this character will be part of the result token. This occurs in (f.e.) |
| // string processing, because we know we need to read until we find the |
| // closing '"' character. |
| // |
| // The second interface is the combination of getCharAndSize with |
| // ConsumeChar. getCharAndSize reads a phase 1/2 translated character, |
| // returning it and its size. If the lexer decides that this character is |
| // part of the current token, it calls ConsumeChar on it. This two stage |
| // approach allows us to emit diagnostics for characters (e.g. warnings about |
| // trigraphs), knowing that they only are emitted if the character is |
| // consumed. |
| |
| /// isObviouslySimpleCharacter - Return true if the specified character is |
| /// obviously the same in translation phase 1 and translation phase 3. This |
| /// can return false for characters that end up being the same, but it will |
| /// never return true for something that needs to be mapped. |
| static bool isObviouslySimpleCharacter(char C) { |
| return C != '?' && C != '\\'; |
| } |
| |
| /// getAndAdvanceChar - Read a single 'character' from the specified buffer, |
| /// advance over it, and return it. This is tricky in several cases. Here we |
| /// just handle the trivial case and fall-back to the non-inlined |
| /// getCharAndSizeSlow method to handle the hard case. |
| inline char getAndAdvanceChar(const char *&Ptr, Token &Tok) { |
| // If this is not a trigraph and not a UCN or escaped newline, return |
| // quickly. |
| if (isObviouslySimpleCharacter(Ptr[0])) return *Ptr++; |
| |
| unsigned Size = 0; |
| char C = getCharAndSizeSlow(Ptr, Size, &Tok); |
| Ptr += Size; |
| return C; |
| } |
| |
| /// ConsumeChar - When a character (identified by getCharAndSize) is consumed |
| /// and added to a given token, check to see if there are diagnostics that |
| /// need to be emitted or flags that need to be set on the token. If so, do |
| /// it. |
| const char *ConsumeChar(const char *Ptr, unsigned Size, Token &Tok) { |
| // Normal case, we consumed exactly one token. Just return it. |
| if (Size == 1) |
| return Ptr+Size; |
| |
| // Otherwise, re-lex the character with a current token, allowing |
| // diagnostics to be emitted and flags to be set. |
| Size = 0; |
| getCharAndSizeSlow(Ptr, Size, &Tok); |
| return Ptr+Size; |
| } |
| |
| /// getCharAndSize - Peek a single 'character' from the specified buffer, |
| /// get its size, and return it. This is tricky in several cases. Here we |
| /// just handle the trivial case and fall-back to the non-inlined |
| /// getCharAndSizeSlow method to handle the hard case. |
| inline char getCharAndSize(const char *Ptr, unsigned &Size) { |
| // If this is not a trigraph and not a UCN or escaped newline, return |
| // quickly. |
| if (isObviouslySimpleCharacter(Ptr[0])) { |
| Size = 1; |
| return *Ptr; |
| } |
| |
| Size = 0; |
| return getCharAndSizeSlow(Ptr, Size); |
| } |
| |
| /// getCharAndSizeSlow - Handle the slow/uncommon case of the getCharAndSize |
| /// method. |
| char getCharAndSizeSlow(const char *Ptr, unsigned &Size, |
| Token *Tok = nullptr); |
| |
| /// getEscapedNewLineSize - Return the size of the specified escaped newline, |
| /// or 0 if it is not an escaped newline. P[-1] is known to be a "\" on entry |
| /// to this function. |
| static unsigned getEscapedNewLineSize(const char *P); |
| |
| /// SkipEscapedNewLines - If P points to an escaped newline (or a series of |
| /// them), skip over them and return the first non-escaped-newline found, |
| /// otherwise return P. |
| static const char *SkipEscapedNewLines(const char *P); |
| |
| /// getCharAndSizeSlowNoWarn - Same as getCharAndSizeSlow, but never emits a |
| /// diagnostic. |
| static char getCharAndSizeSlowNoWarn(const char *Ptr, unsigned &Size, |
| const LangOptions &LangOpts); |
| |
| //===--------------------------------------------------------------------===// |
| // Other lexer functions. |
| |
| void SetByteOffset(unsigned Offset, bool StartOfLine); |
| |
| void PropagateLineStartLeadingSpaceInfo(Token &Result); |
| |
| const char *LexUDSuffix(Token &Result, const char *CurPtr, |
| bool IsStringLiteral); |
| |
| // Helper functions to lex the remainder of a token of the specific type. |
| bool LexIdentifier (Token &Result, const char *CurPtr); |
| bool LexNumericConstant (Token &Result, const char *CurPtr); |
| bool LexStringLiteral (Token &Result, const char *CurPtr, |
| tok::TokenKind Kind); |
| bool LexRawStringLiteral (Token &Result, const char *CurPtr, |
| tok::TokenKind Kind); |
| bool LexAngledStringLiteral(Token &Result, const char *CurPtr); |
| bool LexCharConstant (Token &Result, const char *CurPtr, |
| tok::TokenKind Kind); |
| bool LexEndOfFile (Token &Result, const char *CurPtr); |
| bool SkipWhitespace (Token &Result, const char *CurPtr, |
| bool &TokAtPhysicalStartOfLine); |
| bool SkipLineComment (Token &Result, const char *CurPtr, |
| bool &TokAtPhysicalStartOfLine); |
| bool SkipBlockComment (Token &Result, const char *CurPtr, |
| bool &TokAtPhysicalStartOfLine); |
| bool SaveLineComment (Token &Result, const char *CurPtr); |
| |
| bool IsStartOfConflictMarker(const char *CurPtr); |
| bool HandleEndOfConflictMarker(const char *CurPtr); |
| |
| bool lexEditorPlaceholder(Token &Result, const char *CurPtr); |
| |
| bool isCodeCompletionPoint(const char *CurPtr) const; |
| void cutOffLexing() { BufferPtr = BufferEnd; } |
| |
| bool isHexaLiteral(const char *Start, const LangOptions &LangOpts); |
| |
| |
| /// Read a universal character name. |
| /// |
| /// \param CurPtr The position in the source buffer after the initial '\'. |
| /// If the UCN is syntactically well-formed (but not necessarily |
| /// valid), this parameter will be updated to point to the |
| /// character after the UCN. |
| /// \param SlashLoc The position in the source buffer of the '\'. |
| /// \param Tok The token being formed. Pass \c nullptr to suppress diagnostics |
| /// and handle token formation in the caller. |
| /// |
| /// \return The Unicode codepoint specified by the UCN, or 0 if the UCN is |
| /// invalid. |
| uint32_t tryReadUCN(const char *&CurPtr, const char *SlashLoc, Token *Tok); |
| |
| /// Try to consume a UCN as part of an identifier at the current |
| /// location. |
| /// \param CurPtr Initially points to the range of characters in the source |
| /// buffer containing the '\'. Updated to point past the end of |
| /// the UCN on success. |
| /// \param Size The number of characters occupied by the '\' (including |
| /// trigraphs and escaped newlines). |
| /// \param Result The token being produced. Marked as containing a UCN on |
| /// success. |
| /// \return \c true if a UCN was lexed and it produced an acceptable |
| /// identifier character, \c false otherwise. |
| bool tryConsumeIdentifierUCN(const char *&CurPtr, unsigned Size, |
| Token &Result); |
| |
| /// Try to consume an identifier character encoded in UTF-8. |
| /// \param CurPtr Points to the start of the (potential) UTF-8 code unit |
| /// sequence. On success, updated to point past the end of it. |
| /// \return \c true if a UTF-8 sequence mapping to an acceptable identifier |
| /// character was lexed, \c false otherwise. |
| bool tryConsumeIdentifierUTF8Char(const char *&CurPtr); |
| }; |
| |
| } // namespace clang |
| |
| #endif // LLVM_CLANG_LEX_LEXER_H |