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14 | pmbaty | 1 | //===- Lexer.h - C Language Family Lexer ------------------------*- C++ -*-===// |
2 | // |
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3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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4 | // See https://llvm.org/LICENSE.txt for license information. |
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5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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6 | // |
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7 | //===----------------------------------------------------------------------===// |
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8 | // |
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9 | // This file defines the Lexer interface. |
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10 | // |
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11 | //===----------------------------------------------------------------------===// |
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12 | |||
13 | #ifndef LLVM_CLANG_LEX_LEXER_H |
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14 | #define LLVM_CLANG_LEX_LEXER_H |
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15 | |||
16 | #include "clang/Basic/LangOptions.h" |
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17 | #include "clang/Basic/SourceLocation.h" |
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18 | #include "clang/Basic/TokenKinds.h" |
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19 | #include "clang/Lex/DependencyDirectivesScanner.h" |
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20 | #include "clang/Lex/PreprocessorLexer.h" |
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21 | #include "clang/Lex/Token.h" |
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22 | #include "llvm/ADT/SmallVector.h" |
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23 | #include "llvm/ADT/StringRef.h" |
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24 | #include <cassert> |
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25 | #include <cstdint> |
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26 | #include <optional> |
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27 | #include <string> |
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28 | |||
29 | namespace llvm { |
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30 | |||
31 | class MemoryBufferRef; |
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32 | |||
33 | } // namespace llvm |
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34 | |||
35 | namespace clang { |
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36 | |||
37 | class DiagnosticBuilder; |
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38 | class Preprocessor; |
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39 | class SourceManager; |
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40 | class LangOptions; |
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41 | |||
42 | /// ConflictMarkerKind - Kinds of conflict marker which the lexer might be |
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43 | /// recovering from. |
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44 | enum ConflictMarkerKind { |
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45 | /// Not within a conflict marker. |
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46 | CMK_None, |
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47 | |||
48 | /// A normal or diff3 conflict marker, initiated by at least 7 "<"s, |
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49 | /// separated by at least 7 "="s or "|"s, and terminated by at least 7 ">"s. |
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50 | CMK_Normal, |
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51 | |||
52 | /// A Perforce-style conflict marker, initiated by 4 ">"s, |
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53 | /// separated by 4 "="s, and terminated by 4 "<"s. |
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54 | CMK_Perforce |
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55 | }; |
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56 | |||
57 | /// Describes the bounds (start, size) of the preamble and a flag required by |
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58 | /// PreprocessorOptions::PrecompiledPreambleBytes. |
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59 | /// The preamble includes the BOM, if any. |
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60 | struct PreambleBounds { |
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61 | /// Size of the preamble in bytes. |
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62 | unsigned Size; |
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63 | |||
64 | /// Whether the preamble ends at the start of a new line. |
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65 | /// |
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66 | /// Used to inform the lexer as to whether it's starting at the beginning of |
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67 | /// a line after skipping the preamble. |
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68 | bool PreambleEndsAtStartOfLine; |
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69 | |||
70 | PreambleBounds(unsigned Size, bool PreambleEndsAtStartOfLine) |
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71 | : Size(Size), PreambleEndsAtStartOfLine(PreambleEndsAtStartOfLine) {} |
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72 | }; |
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73 | |||
74 | /// Lexer - This provides a simple interface that turns a text buffer into a |
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75 | /// stream of tokens. This provides no support for file reading or buffering, |
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76 | /// or buffering/seeking of tokens, only forward lexing is supported. It relies |
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77 | /// on the specified Preprocessor object to handle preprocessor directives, etc. |
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78 | class Lexer : public PreprocessorLexer { |
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79 | friend class Preprocessor; |
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80 | |||
81 | void anchor() override; |
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82 | |||
83 | //===--------------------------------------------------------------------===// |
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84 | // Constant configuration values for this lexer. |
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85 | |||
86 | // Start of the buffer. |
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87 | const char *BufferStart; |
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88 | |||
89 | // End of the buffer. |
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90 | const char *BufferEnd; |
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91 | |||
92 | // Location for start of file. |
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93 | SourceLocation FileLoc; |
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94 | |||
95 | // LangOpts enabled by this language. |
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96 | // Storing LangOptions as reference here is important from performance point |
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97 | // of view. Lack of reference means that LangOptions copy constructor would be |
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98 | // called by Lexer(..., const LangOptions &LangOpts,...). Given that local |
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99 | // Lexer objects are created thousands times (in Lexer::getRawToken, |
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100 | // Preprocessor::EnterSourceFile and other places) during single module |
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101 | // processing in frontend it would make std::vector<std::string> copy |
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102 | // constructors surprisingly hot. |
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103 | const LangOptions &LangOpts; |
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104 | |||
105 | // True if '//' line comments are enabled. |
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106 | bool LineComment; |
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107 | |||
108 | // True if lexer for _Pragma handling. |
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109 | bool Is_PragmaLexer; |
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110 | |||
111 | //===--------------------------------------------------------------------===// |
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112 | // Context-specific lexing flags set by the preprocessor. |
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113 | // |
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114 | |||
115 | /// ExtendedTokenMode - The lexer can optionally keep comments and whitespace |
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116 | /// and return them as tokens. This is used for -C and -CC modes, and |
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117 | /// whitespace preservation can be useful for some clients that want to lex |
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118 | /// the file in raw mode and get every character from the file. |
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119 | /// |
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120 | /// When this is set to 2 it returns comments and whitespace. When set to 1 |
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121 | /// it returns comments, when it is set to 0 it returns normal tokens only. |
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122 | unsigned char ExtendedTokenMode; |
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123 | |||
124 | //===--------------------------------------------------------------------===// |
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125 | // Context that changes as the file is lexed. |
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126 | // NOTE: any state that mutates when in raw mode must have save/restore code |
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127 | // in Lexer::isNextPPTokenLParen. |
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128 | |||
129 | // BufferPtr - Current pointer into the buffer. This is the next character |
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130 | // to be lexed. |
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131 | const char *BufferPtr; |
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132 | |||
133 | // IsAtStartOfLine - True if the next lexed token should get the "start of |
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134 | // line" flag set on it. |
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135 | bool IsAtStartOfLine; |
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136 | |||
137 | bool IsAtPhysicalStartOfLine; |
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138 | |||
139 | bool HasLeadingSpace; |
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140 | |||
141 | bool HasLeadingEmptyMacro; |
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142 | |||
143 | /// True if this is the first time we're lexing the input file. |
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144 | bool IsFirstTimeLexingFile; |
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145 | |||
146 | // NewLinePtr - A pointer to new line character '\n' being lexed. For '\r\n', |
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147 | // it also points to '\n.' |
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148 | const char *NewLinePtr; |
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149 | |||
150 | // CurrentConflictMarkerState - The kind of conflict marker we are handling. |
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151 | ConflictMarkerKind CurrentConflictMarkerState; |
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152 | |||
153 | /// Non-empty if this \p Lexer is \p isDependencyDirectivesLexer(). |
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154 | ArrayRef<dependency_directives_scan::Directive> DepDirectives; |
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155 | |||
156 | /// If this \p Lexer is \p isDependencyDirectivesLexer(), it represents the |
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157 | /// next token to use from the current dependency directive. |
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158 | unsigned NextDepDirectiveTokenIndex = 0; |
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159 | |||
160 | void InitLexer(const char *BufStart, const char *BufPtr, const char *BufEnd); |
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161 | |||
162 | public: |
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163 | /// Lexer constructor - Create a new lexer object for the specified buffer |
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164 | /// with the specified preprocessor managing the lexing process. This lexer |
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165 | /// assumes that the associated file buffer and Preprocessor objects will |
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166 | /// outlive it, so it doesn't take ownership of either of them. |
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167 | Lexer(FileID FID, const llvm::MemoryBufferRef &InputFile, Preprocessor &PP, |
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168 | bool IsFirstIncludeOfFile = true); |
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169 | |||
170 | /// Lexer constructor - Create a new raw lexer object. This object is only |
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171 | /// suitable for calls to 'LexFromRawLexer'. This lexer assumes that the |
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172 | /// text range will outlive it, so it doesn't take ownership of it. |
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173 | Lexer(SourceLocation FileLoc, const LangOptions &LangOpts, |
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174 | const char *BufStart, const char *BufPtr, const char *BufEnd, |
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175 | bool IsFirstIncludeOfFile = true); |
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176 | |||
177 | /// Lexer constructor - Create a new raw lexer object. This object is only |
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178 | /// suitable for calls to 'LexFromRawLexer'. This lexer assumes that the |
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179 | /// text range will outlive it, so it doesn't take ownership of it. |
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180 | Lexer(FileID FID, const llvm::MemoryBufferRef &FromFile, |
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181 | const SourceManager &SM, const LangOptions &LangOpts, |
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182 | bool IsFirstIncludeOfFile = true); |
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183 | |||
184 | Lexer(const Lexer &) = delete; |
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185 | Lexer &operator=(const Lexer &) = delete; |
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186 | |||
187 | /// Create_PragmaLexer: Lexer constructor - Create a new lexer object for |
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188 | /// _Pragma expansion. This has a variety of magic semantics that this method |
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189 | /// sets up. It returns a new'd Lexer that must be delete'd when done. |
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190 | static Lexer *Create_PragmaLexer(SourceLocation SpellingLoc, |
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191 | SourceLocation ExpansionLocStart, |
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192 | SourceLocation ExpansionLocEnd, |
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193 | unsigned TokLen, Preprocessor &PP); |
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194 | |||
195 | /// getFileLoc - Return the File Location for the file we are lexing out of. |
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196 | /// The physical location encodes the location where the characters come from, |
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197 | /// the virtual location encodes where we should *claim* the characters came |
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198 | /// from. Currently this is only used by _Pragma handling. |
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199 | SourceLocation getFileLoc() const { return FileLoc; } |
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200 | |||
201 | private: |
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202 | /// Lex - Return the next token in the file. If this is the end of file, it |
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203 | /// return the tok::eof token. This implicitly involves the preprocessor. |
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204 | bool Lex(Token &Result); |
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205 | |||
206 | /// Called when the preprocessor is in 'dependency scanning lexing mode'. |
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207 | bool LexDependencyDirectiveToken(Token &Result); |
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208 | |||
209 | /// Called when the preprocessor is in 'dependency scanning lexing mode' and |
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210 | /// is skipping a conditional block. |
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211 | bool LexDependencyDirectiveTokenWhileSkipping(Token &Result); |
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212 | |||
213 | /// True when the preprocessor is in 'dependency scanning lexing mode' and |
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214 | /// created this \p Lexer for lexing a set of dependency directive tokens. |
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215 | bool isDependencyDirectivesLexer() const { return !DepDirectives.empty(); } |
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216 | |||
217 | /// Initializes \p Result with data from \p DDTok and advances \p BufferPtr to |
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218 | /// the position just after the token. |
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219 | /// \returns the buffer pointer at the beginning of the token. |
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220 | const char *convertDependencyDirectiveToken( |
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221 | const dependency_directives_scan::Token &DDTok, Token &Result); |
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222 | |||
223 | public: |
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224 | /// isPragmaLexer - Returns true if this Lexer is being used to lex a pragma. |
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225 | bool isPragmaLexer() const { return Is_PragmaLexer; } |
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226 | |||
227 | private: |
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228 | /// IndirectLex - An indirect call to 'Lex' that can be invoked via |
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229 | /// the PreprocessorLexer interface. |
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230 | void IndirectLex(Token &Result) override { Lex(Result); } |
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231 | |||
232 | public: |
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233 | /// LexFromRawLexer - Lex a token from a designated raw lexer (one with no |
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234 | /// associated preprocessor object. Return true if the 'next character to |
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235 | /// read' pointer points at the end of the lexer buffer, false otherwise. |
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236 | bool LexFromRawLexer(Token &Result) { |
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237 | assert(LexingRawMode && "Not already in raw mode!"); |
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238 | Lex(Result); |
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239 | // Note that lexing to the end of the buffer doesn't implicitly delete the |
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240 | // lexer when in raw mode. |
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241 | return BufferPtr == BufferEnd; |
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242 | } |
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243 | |||
244 | /// isKeepWhitespaceMode - Return true if the lexer should return tokens for |
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245 | /// every character in the file, including whitespace and comments. This |
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246 | /// should only be used in raw mode, as the preprocessor is not prepared to |
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247 | /// deal with the excess tokens. |
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248 | bool isKeepWhitespaceMode() const { |
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249 | return ExtendedTokenMode > 1; |
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250 | } |
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251 | |||
252 | /// SetKeepWhitespaceMode - This method lets clients enable or disable |
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253 | /// whitespace retention mode. |
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254 | void SetKeepWhitespaceMode(bool Val) { |
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255 | assert((!Val || LexingRawMode || LangOpts.TraditionalCPP) && |
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256 | "Can only retain whitespace in raw mode or -traditional-cpp"); |
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257 | ExtendedTokenMode = Val ? 2 : 0; |
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258 | } |
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259 | |||
260 | /// inKeepCommentMode - Return true if the lexer should return comments as |
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261 | /// tokens. |
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262 | bool inKeepCommentMode() const { |
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263 | return ExtendedTokenMode > 0; |
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264 | } |
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265 | |||
266 | /// SetCommentRetentionMode - Change the comment retention mode of the lexer |
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267 | /// to the specified mode. This is really only useful when lexing in raw |
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268 | /// mode, because otherwise the lexer needs to manage this. |
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269 | void SetCommentRetentionState(bool Mode) { |
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270 | assert(!isKeepWhitespaceMode() && |
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271 | "Can't play with comment retention state when retaining whitespace"); |
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272 | ExtendedTokenMode = Mode ? 1 : 0; |
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273 | } |
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274 | |||
275 | /// Sets the extended token mode back to its initial value, according to the |
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276 | /// language options and preprocessor. This controls whether the lexer |
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277 | /// produces comment and whitespace tokens. |
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278 | /// |
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279 | /// This requires the lexer to have an associated preprocessor. A standalone |
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280 | /// lexer has nothing to reset to. |
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281 | void resetExtendedTokenMode(); |
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282 | |||
283 | /// Gets source code buffer. |
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284 | StringRef getBuffer() const { |
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285 | return StringRef(BufferStart, BufferEnd - BufferStart); |
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286 | } |
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287 | |||
288 | /// ReadToEndOfLine - Read the rest of the current preprocessor line as an |
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289 | /// uninterpreted string. This switches the lexer out of directive mode. |
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290 | void ReadToEndOfLine(SmallVectorImpl<char> *Result = nullptr); |
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291 | |||
292 | |||
293 | /// Diag - Forwarding function for diagnostics. This translate a source |
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294 | /// position in the current buffer into a SourceLocation object for rendering. |
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295 | DiagnosticBuilder Diag(const char *Loc, unsigned DiagID) const; |
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296 | |||
297 | /// getSourceLocation - Return a source location identifier for the specified |
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298 | /// offset in the current file. |
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299 | SourceLocation getSourceLocation(const char *Loc, unsigned TokLen = 1) const; |
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300 | |||
301 | /// getSourceLocation - Return a source location for the next character in |
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302 | /// the current file. |
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303 | SourceLocation getSourceLocation() override { |
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304 | return getSourceLocation(BufferPtr); |
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305 | } |
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306 | |||
307 | /// Return the current location in the buffer. |
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308 | const char *getBufferLocation() const { return BufferPtr; } |
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309 | |||
310 | /// Returns the current lexing offset. |
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311 | unsigned getCurrentBufferOffset() { |
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312 | assert(BufferPtr >= BufferStart && "Invalid buffer state"); |
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313 | return BufferPtr - BufferStart; |
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314 | } |
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315 | |||
316 | /// Set the lexer's buffer pointer to \p Offset. |
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317 | void seek(unsigned Offset, bool IsAtStartOfLine); |
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318 | |||
319 | /// Stringify - Convert the specified string into a C string by i) escaping |
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320 | /// '\\' and " characters and ii) replacing newline character(s) with "\\n". |
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321 | /// If Charify is true, this escapes the ' character instead of ". |
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322 | static std::string Stringify(StringRef Str, bool Charify = false); |
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323 | |||
324 | /// Stringify - Convert the specified string into a C string by i) escaping |
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325 | /// '\\' and " characters and ii) replacing newline character(s) with "\\n". |
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326 | static void Stringify(SmallVectorImpl<char> &Str); |
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327 | |||
328 | /// getSpelling - This method is used to get the spelling of a token into a |
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329 | /// preallocated buffer, instead of as an std::string. The caller is required |
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330 | /// to allocate enough space for the token, which is guaranteed to be at least |
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331 | /// Tok.getLength() bytes long. The length of the actual result is returned. |
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332 | /// |
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333 | /// Note that this method may do two possible things: it may either fill in |
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334 | /// the buffer specified with characters, or it may *change the input pointer* |
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335 | /// to point to a constant buffer with the data already in it (avoiding a |
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336 | /// copy). The caller is not allowed to modify the returned buffer pointer |
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337 | /// if an internal buffer is returned. |
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338 | static unsigned getSpelling(const Token &Tok, const char *&Buffer, |
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339 | const SourceManager &SourceMgr, |
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340 | const LangOptions &LangOpts, |
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341 | bool *Invalid = nullptr); |
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342 | |||
343 | /// getSpelling() - Return the 'spelling' of the Tok token. The spelling of a |
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344 | /// token is the characters used to represent the token in the source file |
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345 | /// after trigraph expansion and escaped-newline folding. In particular, this |
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346 | /// wants to get the true, uncanonicalized, spelling of things like digraphs |
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347 | /// UCNs, etc. |
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348 | static std::string getSpelling(const Token &Tok, |
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349 | const SourceManager &SourceMgr, |
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350 | const LangOptions &LangOpts, |
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351 | bool *Invalid = nullptr); |
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352 | |||
353 | /// getSpelling - This method is used to get the spelling of the |
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354 | /// token at the given source location. If, as is usually true, it |
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355 | /// is not necessary to copy any data, then the returned string may |
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356 | /// not point into the provided buffer. |
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357 | /// |
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358 | /// This method lexes at the expansion depth of the given |
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359 | /// location and does not jump to the expansion or spelling |
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360 | /// location. |
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361 | static StringRef getSpelling(SourceLocation loc, |
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362 | SmallVectorImpl<char> &buffer, |
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363 | const SourceManager &SM, |
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364 | const LangOptions &options, |
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365 | bool *invalid = nullptr); |
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366 | |||
367 | /// MeasureTokenLength - Relex the token at the specified location and return |
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368 | /// its length in bytes in the input file. If the token needs cleaning (e.g. |
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369 | /// includes a trigraph or an escaped newline) then this count includes bytes |
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370 | /// that are part of that. |
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371 | static unsigned MeasureTokenLength(SourceLocation Loc, |
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372 | const SourceManager &SM, |
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373 | const LangOptions &LangOpts); |
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374 | |||
375 | /// Relex the token at the specified location. |
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376 | /// \returns true if there was a failure, false on success. |
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377 | static bool getRawToken(SourceLocation Loc, Token &Result, |
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378 | const SourceManager &SM, |
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379 | const LangOptions &LangOpts, |
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380 | bool IgnoreWhiteSpace = false); |
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381 | |||
382 | /// Given a location any where in a source buffer, find the location |
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383 | /// that corresponds to the beginning of the token in which the original |
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384 | /// source location lands. |
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385 | static SourceLocation GetBeginningOfToken(SourceLocation Loc, |
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386 | const SourceManager &SM, |
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387 | const LangOptions &LangOpts); |
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388 | |||
389 | /// Get the physical length (including trigraphs and escaped newlines) of the |
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390 | /// first \p Characters characters of the token starting at TokStart. |
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391 | static unsigned getTokenPrefixLength(SourceLocation TokStart, |
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392 | unsigned CharNo, |
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393 | const SourceManager &SM, |
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394 | const LangOptions &LangOpts); |
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395 | |||
396 | /// AdvanceToTokenCharacter - If the current SourceLocation specifies a |
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397 | /// location at the start of a token, return a new location that specifies a |
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398 | /// character within the token. This handles trigraphs and escaped newlines. |
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399 | static SourceLocation AdvanceToTokenCharacter(SourceLocation TokStart, |
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400 | unsigned Characters, |
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401 | const SourceManager &SM, |
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402 | const LangOptions &LangOpts) { |
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403 | return TokStart.getLocWithOffset( |
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404 | getTokenPrefixLength(TokStart, Characters, SM, LangOpts)); |
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405 | } |
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406 | |||
407 | /// Computes the source location just past the end of the |
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408 | /// token at this source location. |
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409 | /// |
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410 | /// This routine can be used to produce a source location that |
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411 | /// points just past the end of the token referenced by \p Loc, and |
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412 | /// is generally used when a diagnostic needs to point just after a |
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413 | /// token where it expected something different that it received. If |
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414 | /// the returned source location would not be meaningful (e.g., if |
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415 | /// it points into a macro), this routine returns an invalid |
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416 | /// source location. |
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417 | /// |
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418 | /// \param Offset an offset from the end of the token, where the source |
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419 | /// location should refer to. The default offset (0) produces a source |
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420 | /// location pointing just past the end of the token; an offset of 1 produces |
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421 | /// a source location pointing to the last character in the token, etc. |
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422 | static SourceLocation getLocForEndOfToken(SourceLocation Loc, unsigned Offset, |
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423 | const SourceManager &SM, |
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424 | const LangOptions &LangOpts); |
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425 | |||
426 | /// Given a token range, produce a corresponding CharSourceRange that |
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427 | /// is not a token range. This allows the source range to be used by |
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428 | /// components that don't have access to the lexer and thus can't find the |
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429 | /// end of the range for themselves. |
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430 | static CharSourceRange getAsCharRange(SourceRange Range, |
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431 | const SourceManager &SM, |
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432 | const LangOptions &LangOpts) { |
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433 | SourceLocation End = getLocForEndOfToken(Range.getEnd(), 0, SM, LangOpts); |
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434 | return End.isInvalid() ? CharSourceRange() |
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435 | : CharSourceRange::getCharRange( |
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436 | Range.getBegin(), End); |
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437 | } |
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438 | static CharSourceRange getAsCharRange(CharSourceRange Range, |
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439 | const SourceManager &SM, |
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440 | const LangOptions &LangOpts) { |
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441 | return Range.isTokenRange() |
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442 | ? getAsCharRange(Range.getAsRange(), SM, LangOpts) |
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443 | : Range; |
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444 | } |
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445 | |||
446 | /// Returns true if the given MacroID location points at the first |
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447 | /// token of the macro expansion. |
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448 | /// |
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449 | /// \param MacroBegin If non-null and function returns true, it is set to |
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450 | /// begin location of the macro. |
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451 | static bool isAtStartOfMacroExpansion(SourceLocation loc, |
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452 | const SourceManager &SM, |
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453 | const LangOptions &LangOpts, |
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454 | SourceLocation *MacroBegin = nullptr); |
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455 | |||
456 | /// Returns true if the given MacroID location points at the last |
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457 | /// token of the macro expansion. |
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458 | /// |
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459 | /// \param MacroEnd If non-null and function returns true, it is set to |
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460 | /// end location of the macro. |
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461 | static bool isAtEndOfMacroExpansion(SourceLocation loc, |
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462 | const SourceManager &SM, |
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463 | const LangOptions &LangOpts, |
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464 | SourceLocation *MacroEnd = nullptr); |
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465 | |||
466 | /// Accepts a range and returns a character range with file locations. |
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467 | /// |
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468 | /// Returns a null range if a part of the range resides inside a macro |
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469 | /// expansion or the range does not reside on the same FileID. |
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470 | /// |
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471 | /// This function is trying to deal with macros and return a range based on |
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472 | /// file locations. The cases where it can successfully handle macros are: |
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473 | /// |
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474 | /// -begin or end range lies at the start or end of a macro expansion, in |
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475 | /// which case the location will be set to the expansion point, e.g: |
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476 | /// \#define M 1 2 |
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477 | /// a M |
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478 | /// If you have a range [a, 2] (where 2 came from the macro), the function |
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479 | /// will return a range for "a M" |
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480 | /// if you have range [a, 1], the function will fail because the range |
||
481 | /// overlaps with only a part of the macro |
||
482 | /// |
||
483 | /// -The macro is a function macro and the range can be mapped to the macro |
||
484 | /// arguments, e.g: |
||
485 | /// \#define M 1 2 |
||
486 | /// \#define FM(x) x |
||
487 | /// FM(a b M) |
||
488 | /// if you have range [b, 2], the function will return the file range "b M" |
||
489 | /// inside the macro arguments. |
||
490 | /// if you have range [a, 2], the function will return the file range |
||
491 | /// "FM(a b M)" since the range includes all of the macro expansion. |
||
492 | static CharSourceRange makeFileCharRange(CharSourceRange Range, |
||
493 | const SourceManager &SM, |
||
494 | const LangOptions &LangOpts); |
||
495 | |||
496 | /// Returns a string for the source that the range encompasses. |
||
497 | static StringRef getSourceText(CharSourceRange Range, |
||
498 | const SourceManager &SM, |
||
499 | const LangOptions &LangOpts, |
||
500 | bool *Invalid = nullptr); |
||
501 | |||
502 | /// Retrieve the name of the immediate macro expansion. |
||
503 | /// |
||
504 | /// This routine starts from a source location, and finds the name of the macro |
||
505 | /// responsible for its immediate expansion. It looks through any intervening |
||
506 | /// macro argument expansions to compute this. It returns a StringRef which |
||
507 | /// refers to the SourceManager-owned buffer of the source where that macro |
||
508 | /// name is spelled. Thus, the result shouldn't out-live that SourceManager. |
||
509 | static StringRef getImmediateMacroName(SourceLocation Loc, |
||
510 | const SourceManager &SM, |
||
511 | const LangOptions &LangOpts); |
||
512 | |||
513 | /// Retrieve the name of the immediate macro expansion. |
||
514 | /// |
||
515 | /// This routine starts from a source location, and finds the name of the |
||
516 | /// macro responsible for its immediate expansion. It looks through any |
||
517 | /// intervening macro argument expansions to compute this. It returns a |
||
518 | /// StringRef which refers to the SourceManager-owned buffer of the source |
||
519 | /// where that macro name is spelled. Thus, the result shouldn't out-live |
||
520 | /// that SourceManager. |
||
521 | /// |
||
522 | /// This differs from Lexer::getImmediateMacroName in that any macro argument |
||
523 | /// location will result in the topmost function macro that accepted it. |
||
524 | /// e.g. |
||
525 | /// \code |
||
526 | /// MAC1( MAC2(foo) ) |
||
527 | /// \endcode |
||
528 | /// for location of 'foo' token, this function will return "MAC1" while |
||
529 | /// Lexer::getImmediateMacroName will return "MAC2". |
||
530 | static StringRef getImmediateMacroNameForDiagnostics( |
||
531 | SourceLocation Loc, const SourceManager &SM, const LangOptions &LangOpts); |
||
532 | |||
533 | /// Compute the preamble of the given file. |
||
534 | /// |
||
535 | /// The preamble of a file contains the initial comments, include directives, |
||
536 | /// and other preprocessor directives that occur before the code in this |
||
537 | /// particular file actually begins. The preamble of the main source file is |
||
538 | /// a potential prefix header. |
||
539 | /// |
||
540 | /// \param Buffer The memory buffer containing the file's contents. |
||
541 | /// |
||
542 | /// \param MaxLines If non-zero, restrict the length of the preamble |
||
543 | /// to fewer than this number of lines. |
||
544 | /// |
||
545 | /// \returns The offset into the file where the preamble ends and the rest |
||
546 | /// of the file begins along with a boolean value indicating whether |
||
547 | /// the preamble ends at the beginning of a new line. |
||
548 | static PreambleBounds ComputePreamble(StringRef Buffer, |
||
549 | const LangOptions &LangOpts, |
||
550 | unsigned MaxLines = 0); |
||
551 | |||
552 | /// Finds the token that comes right after the given location. |
||
553 | /// |
||
554 | /// Returns the next token, or none if the location is inside a macro. |
||
555 | static std::optional<Token> findNextToken(SourceLocation Loc, |
||
556 | const SourceManager &SM, |
||
557 | const LangOptions &LangOpts); |
||
558 | |||
559 | /// Checks that the given token is the first token that occurs after |
||
560 | /// the given location (this excludes comments and whitespace). Returns the |
||
561 | /// location immediately after the specified token. If the token is not found |
||
562 | /// or the location is inside a macro, the returned source location will be |
||
563 | /// invalid. |
||
564 | static SourceLocation findLocationAfterToken(SourceLocation loc, |
||
565 | tok::TokenKind TKind, |
||
566 | const SourceManager &SM, |
||
567 | const LangOptions &LangOpts, |
||
568 | bool SkipTrailingWhitespaceAndNewLine); |
||
569 | |||
570 | /// Returns true if the given character could appear in an identifier. |
||
571 | static bool isAsciiIdentifierContinueChar(char c, |
||
572 | const LangOptions &LangOpts); |
||
573 | |||
574 | /// Checks whether new line pointed by Str is preceded by escape |
||
575 | /// sequence. |
||
576 | static bool isNewLineEscaped(const char *BufferStart, const char *Str); |
||
577 | |||
578 | /// getCharAndSizeNoWarn - Like the getCharAndSize method, but does not ever |
||
579 | /// emit a warning. |
||
580 | static inline char getCharAndSizeNoWarn(const char *Ptr, unsigned &Size, |
||
581 | const LangOptions &LangOpts) { |
||
582 | // If this is not a trigraph and not a UCN or escaped newline, return |
||
583 | // quickly. |
||
584 | if (isObviouslySimpleCharacter(Ptr[0])) { |
||
585 | Size = 1; |
||
586 | return *Ptr; |
||
587 | } |
||
588 | |||
589 | Size = 0; |
||
590 | return getCharAndSizeSlowNoWarn(Ptr, Size, LangOpts); |
||
591 | } |
||
592 | |||
593 | /// Returns the leading whitespace for line that corresponds to the given |
||
594 | /// location \p Loc. |
||
595 | static StringRef getIndentationForLine(SourceLocation Loc, |
||
596 | const SourceManager &SM); |
||
597 | |||
598 | /// Check if this is the first time we're lexing the input file. |
||
599 | bool isFirstTimeLexingFile() const { return IsFirstTimeLexingFile; } |
||
600 | |||
601 | private: |
||
602 | //===--------------------------------------------------------------------===// |
||
603 | // Internal implementation interfaces. |
||
604 | |||
605 | /// LexTokenInternal - Internal interface to lex a preprocessing token. Called |
||
606 | /// by Lex. |
||
607 | /// |
||
608 | bool LexTokenInternal(Token &Result, bool TokAtPhysicalStartOfLine); |
||
609 | |||
610 | bool CheckUnicodeWhitespace(Token &Result, uint32_t C, const char *CurPtr); |
||
611 | |||
612 | bool LexUnicodeIdentifierStart(Token &Result, uint32_t C, const char *CurPtr); |
||
613 | |||
614 | /// FormTokenWithChars - When we lex a token, we have identified a span |
||
615 | /// starting at BufferPtr, going to TokEnd that forms the token. This method |
||
616 | /// takes that range and assigns it to the token as its location and size. In |
||
617 | /// addition, since tokens cannot overlap, this also updates BufferPtr to be |
||
618 | /// TokEnd. |
||
619 | void FormTokenWithChars(Token &Result, const char *TokEnd, |
||
620 | tok::TokenKind Kind) { |
||
621 | unsigned TokLen = TokEnd-BufferPtr; |
||
622 | Result.setLength(TokLen); |
||
623 | Result.setLocation(getSourceLocation(BufferPtr, TokLen)); |
||
624 | Result.setKind(Kind); |
||
625 | BufferPtr = TokEnd; |
||
626 | } |
||
627 | |||
628 | /// isNextPPTokenLParen - Return 1 if the next unexpanded token will return a |
||
629 | /// tok::l_paren token, 0 if it is something else and 2 if there are no more |
||
630 | /// tokens in the buffer controlled by this lexer. |
||
631 | unsigned isNextPPTokenLParen(); |
||
632 | |||
633 | //===--------------------------------------------------------------------===// |
||
634 | // Lexer character reading interfaces. |
||
635 | |||
636 | // This lexer is built on two interfaces for reading characters, both of which |
||
637 | // automatically provide phase 1/2 translation. getAndAdvanceChar is used |
||
638 | // when we know that we will be reading a character from the input buffer and |
||
639 | // that this character will be part of the result token. This occurs in (f.e.) |
||
640 | // string processing, because we know we need to read until we find the |
||
641 | // closing '"' character. |
||
642 | // |
||
643 | // The second interface is the combination of getCharAndSize with |
||
644 | // ConsumeChar. getCharAndSize reads a phase 1/2 translated character, |
||
645 | // returning it and its size. If the lexer decides that this character is |
||
646 | // part of the current token, it calls ConsumeChar on it. This two stage |
||
647 | // approach allows us to emit diagnostics for characters (e.g. warnings about |
||
648 | // trigraphs), knowing that they only are emitted if the character is |
||
649 | // consumed. |
||
650 | |||
651 | /// isObviouslySimpleCharacter - Return true if the specified character is |
||
652 | /// obviously the same in translation phase 1 and translation phase 3. This |
||
653 | /// can return false for characters that end up being the same, but it will |
||
654 | /// never return true for something that needs to be mapped. |
||
655 | static bool isObviouslySimpleCharacter(char C) { |
||
656 | return C != '?' && C != '\\'; |
||
657 | } |
||
658 | |||
659 | /// getAndAdvanceChar - Read a single 'character' from the specified buffer, |
||
660 | /// advance over it, and return it. This is tricky in several cases. Here we |
||
661 | /// just handle the trivial case and fall-back to the non-inlined |
||
662 | /// getCharAndSizeSlow method to handle the hard case. |
||
663 | inline char getAndAdvanceChar(const char *&Ptr, Token &Tok) { |
||
664 | // If this is not a trigraph and not a UCN or escaped newline, return |
||
665 | // quickly. |
||
666 | if (isObviouslySimpleCharacter(Ptr[0])) return *Ptr++; |
||
667 | |||
668 | unsigned Size = 0; |
||
669 | char C = getCharAndSizeSlow(Ptr, Size, &Tok); |
||
670 | Ptr += Size; |
||
671 | return C; |
||
672 | } |
||
673 | |||
674 | /// ConsumeChar - When a character (identified by getCharAndSize) is consumed |
||
675 | /// and added to a given token, check to see if there are diagnostics that |
||
676 | /// need to be emitted or flags that need to be set on the token. If so, do |
||
677 | /// it. |
||
678 | const char *ConsumeChar(const char *Ptr, unsigned Size, Token &Tok) { |
||
679 | // Normal case, we consumed exactly one token. Just return it. |
||
680 | if (Size == 1) |
||
681 | return Ptr+Size; |
||
682 | |||
683 | // Otherwise, re-lex the character with a current token, allowing |
||
684 | // diagnostics to be emitted and flags to be set. |
||
685 | Size = 0; |
||
686 | getCharAndSizeSlow(Ptr, Size, &Tok); |
||
687 | return Ptr+Size; |
||
688 | } |
||
689 | |||
690 | /// getCharAndSize - Peek a single 'character' from the specified buffer, |
||
691 | /// get its size, and return it. This is tricky in several cases. Here we |
||
692 | /// just handle the trivial case and fall-back to the non-inlined |
||
693 | /// getCharAndSizeSlow method to handle the hard case. |
||
694 | inline char getCharAndSize(const char *Ptr, unsigned &Size) { |
||
695 | // If this is not a trigraph and not a UCN or escaped newline, return |
||
696 | // quickly. |
||
697 | if (isObviouslySimpleCharacter(Ptr[0])) { |
||
698 | Size = 1; |
||
699 | return *Ptr; |
||
700 | } |
||
701 | |||
702 | Size = 0; |
||
703 | return getCharAndSizeSlow(Ptr, Size); |
||
704 | } |
||
705 | |||
706 | /// getCharAndSizeSlow - Handle the slow/uncommon case of the getCharAndSize |
||
707 | /// method. |
||
708 | char getCharAndSizeSlow(const char *Ptr, unsigned &Size, |
||
709 | Token *Tok = nullptr); |
||
710 | |||
711 | /// getEscapedNewLineSize - Return the size of the specified escaped newline, |
||
712 | /// or 0 if it is not an escaped newline. P[-1] is known to be a "\" on entry |
||
713 | /// to this function. |
||
714 | static unsigned getEscapedNewLineSize(const char *P); |
||
715 | |||
716 | /// SkipEscapedNewLines - If P points to an escaped newline (or a series of |
||
717 | /// them), skip over them and return the first non-escaped-newline found, |
||
718 | /// otherwise return P. |
||
719 | static const char *SkipEscapedNewLines(const char *P); |
||
720 | |||
721 | /// getCharAndSizeSlowNoWarn - Same as getCharAndSizeSlow, but never emits a |
||
722 | /// diagnostic. |
||
723 | static char getCharAndSizeSlowNoWarn(const char *Ptr, unsigned &Size, |
||
724 | const LangOptions &LangOpts); |
||
725 | |||
726 | //===--------------------------------------------------------------------===// |
||
727 | // Other lexer functions. |
||
728 | |||
729 | void SetByteOffset(unsigned Offset, bool StartOfLine); |
||
730 | |||
731 | void PropagateLineStartLeadingSpaceInfo(Token &Result); |
||
732 | |||
733 | const char *LexUDSuffix(Token &Result, const char *CurPtr, |
||
734 | bool IsStringLiteral); |
||
735 | |||
736 | // Helper functions to lex the remainder of a token of the specific type. |
||
737 | |||
738 | // This function handles both ASCII and Unicode identifiers after |
||
739 | // the first codepoint of the identifyier has been parsed. |
||
740 | bool LexIdentifierContinue(Token &Result, const char *CurPtr); |
||
741 | |||
742 | bool LexNumericConstant (Token &Result, const char *CurPtr); |
||
743 | bool LexStringLiteral (Token &Result, const char *CurPtr, |
||
744 | tok::TokenKind Kind); |
||
745 | bool LexRawStringLiteral (Token &Result, const char *CurPtr, |
||
746 | tok::TokenKind Kind); |
||
747 | bool LexAngledStringLiteral(Token &Result, const char *CurPtr); |
||
748 | bool LexCharConstant (Token &Result, const char *CurPtr, |
||
749 | tok::TokenKind Kind); |
||
750 | bool LexEndOfFile (Token &Result, const char *CurPtr); |
||
751 | bool SkipWhitespace (Token &Result, const char *CurPtr, |
||
752 | bool &TokAtPhysicalStartOfLine); |
||
753 | bool SkipLineComment (Token &Result, const char *CurPtr, |
||
754 | bool &TokAtPhysicalStartOfLine); |
||
755 | bool SkipBlockComment (Token &Result, const char *CurPtr, |
||
756 | bool &TokAtPhysicalStartOfLine); |
||
757 | bool SaveLineComment (Token &Result, const char *CurPtr); |
||
758 | |||
759 | bool IsStartOfConflictMarker(const char *CurPtr); |
||
760 | bool HandleEndOfConflictMarker(const char *CurPtr); |
||
761 | |||
762 | bool lexEditorPlaceholder(Token &Result, const char *CurPtr); |
||
763 | |||
764 | bool isCodeCompletionPoint(const char *CurPtr) const; |
||
765 | void cutOffLexing() { BufferPtr = BufferEnd; } |
||
766 | |||
767 | bool isHexaLiteral(const char *Start, const LangOptions &LangOpts); |
||
768 | |||
769 | void codeCompleteIncludedFile(const char *PathStart, |
||
770 | const char *CompletionPoint, bool IsAngled); |
||
771 | |||
772 | std::optional<uint32_t> |
||
773 | tryReadNumericUCN(const char *&StartPtr, const char *SlashLoc, Token *Result); |
||
774 | std::optional<uint32_t> tryReadNamedUCN(const char *&StartPtr, |
||
775 | const char *SlashLoc, Token *Result); |
||
776 | |||
777 | /// Read a universal character name. |
||
778 | /// |
||
779 | /// \param StartPtr The position in the source buffer after the initial '\'. |
||
780 | /// If the UCN is syntactically well-formed (but not |
||
781 | /// necessarily valid), this parameter will be updated to |
||
782 | /// point to the character after the UCN. |
||
783 | /// \param SlashLoc The position in the source buffer of the '\'. |
||
784 | /// \param Result The token being formed. Pass \c nullptr to suppress |
||
785 | /// diagnostics and handle token formation in the caller. |
||
786 | /// |
||
787 | /// \return The Unicode codepoint specified by the UCN, or 0 if the UCN is |
||
788 | /// invalid. |
||
789 | uint32_t tryReadUCN(const char *&StartPtr, const char *SlashLoc, Token *Result); |
||
790 | |||
791 | /// Try to consume a UCN as part of an identifier at the current |
||
792 | /// location. |
||
793 | /// \param CurPtr Initially points to the range of characters in the source |
||
794 | /// buffer containing the '\'. Updated to point past the end of |
||
795 | /// the UCN on success. |
||
796 | /// \param Size The number of characters occupied by the '\' (including |
||
797 | /// trigraphs and escaped newlines). |
||
798 | /// \param Result The token being produced. Marked as containing a UCN on |
||
799 | /// success. |
||
800 | /// \return \c true if a UCN was lexed and it produced an acceptable |
||
801 | /// identifier character, \c false otherwise. |
||
802 | bool tryConsumeIdentifierUCN(const char *&CurPtr, unsigned Size, |
||
803 | Token &Result); |
||
804 | |||
805 | /// Try to consume an identifier character encoded in UTF-8. |
||
806 | /// \param CurPtr Points to the start of the (potential) UTF-8 code unit |
||
807 | /// sequence. On success, updated to point past the end of it. |
||
808 | /// \return \c true if a UTF-8 sequence mapping to an acceptable identifier |
||
809 | /// character was lexed, \c false otherwise. |
||
810 | bool tryConsumeIdentifierUTF8Char(const char *&CurPtr); |
||
811 | }; |
||
812 | |||
813 | } // namespace clang |
||
814 | |||
815 | #endif // LLVM_CLANG_LEX_LEXER_H |