clang/lib/Format/FormatTokenLexer.h

   1 //===--- FormatTokenLexer.h - Format C++ code ----------------*- C++ ----*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 ///
   9 /// \file
  10 /// This file contains FormatTokenLexer, which tokenizes a source file
  11 /// into a token stream suitable for ClangFormat.
  12 ///
  13 //===----------------------------------------------------------------------===//
  14
  15 #ifndef LLVM_CLANG_LIB_FORMAT_FORMATTOKENLEXER_H
  16 #define LLVM_CLANG_LIB_FORMAT_FORMATTOKENLEXER_H
  17
  18 #include "Encoding.h"
  19 #include "FormatToken.h"
  20 #include "llvm/ADT/MapVector.h"
  21 #include "llvm/ADT/SmallPtrSet.h"
  22 #include "llvm/ADT/StringSet.h"
  23
  24 #include <stack>
  25
  26 namespace clang {
  27 namespace format {
  28
  29 enum LexerState {
  30   NORMAL,
  31   TEMPLATE_STRING,
  32   TOKEN_STASHED,
  33 };
  34
  35 class FormatTokenLexer {
  36 public:
  37   FormatTokenLexer(const SourceManager &SourceMgr, FileID ID, unsigned Column,
  38                    const FormatStyle &Style, encoding::Encoding Encoding,
  39                    llvm::SpecificBumpPtrAllocator<FormatToken> &Allocator,
  40                    IdentifierTable &IdentTable);
  41
  42   ArrayRef<FormatToken *> lex();
  43
  44   const AdditionalKeywords &getKeywords() { return Keywords; }
  45
  46 private:
  47   void tryMergePreviousTokens();
  48
  49   bool tryMergeLessLess();
  50   bool tryMergeGreaterGreater();
  51   bool tryMergeNSStringLiteral();
  52   bool tryMergeJSPrivateIdentifier();
  53   bool tryMergeCSharpStringLiteral();
  54   bool tryMergeCSharpKeywordVariables();
  55   bool tryMergeNullishCoalescingEqual();
  56   bool tryTransformCSharpForEach();
  57   bool tryMergeForEach();
  58   bool tryTransformTryUsageForC();
  59
  60   // Merge the most recently lexed tokens into a single token if their kinds are
  61   // correct.
  62   bool tryMergeTokens(ArrayRef<tok::TokenKind> Kinds, TokenType NewType);
  63   // Merge without checking their kinds.
  64   bool tryMergeTokens(size_t Count, TokenType NewType);
  65   // Merge if their kinds match any one of Kinds.
  66   bool tryMergeTokensAny(ArrayRef<ArrayRef<tok::TokenKind>> Kinds,
  67                          TokenType NewType);
  68
  69   // Returns \c true if \p Tok can only be followed by an operand in JavaScript.
  70   bool precedesOperand(FormatToken *Tok);
  71
  72   bool canPrecedeRegexLiteral(FormatToken *Prev);
  73
  74   // Tries to parse a JavaScript Regex literal starting at the current token,
  75   // if that begins with a slash and is in a location where JavaScript allows
  76   // regex literals. Changes the current token to a regex literal and updates
  77   // its text if successful.
  78   void tryParseJSRegexLiteral();
  79
  80   // Handles JavaScript template strings.
  81   //
  82   // JavaScript template strings use backticks ('`') as delimiters, and allow
  83   // embedding expressions nested in ${expr-here}. Template strings can be
  84   // nested recursively, i.e. expressions can contain template strings in turn.
  85   //
  86   // The code below parses starting from a backtick, up to a closing backtick or
  87   // an opening ${. It also maintains a stack of lexing contexts to handle
  88   // nested template parts by balancing curly braces.
  89   void handleTemplateStrings();
  90
  91   void handleCSharpVerbatimAndInterpolatedStrings();
  92
  93   // Handles TableGen multiline strings. It has the form [{ ... }].
  94   void handleTableGenMultilineString();
  95   // Handles TableGen numeric like identifiers.
  96   // They have a forms of [0-9]*[_a-zA-Z]([_a-zA-Z0-9]*). But limited to the
  97   // case it is not lexed as an integer.
  98   void handleTableGenNumericLikeIdentifier();
  99
 100   void tryParsePythonComment();
 101
 102   bool tryMerge_TMacro();
 103
 104   bool tryMergeConflictMarkers();
 105
 106   void truncateToken(size_t NewLen);
 107
 108   FormatToken *getStashedToken();
 109
 110   FormatToken *getNextToken();
 111
 112   FormatToken *FormatTok;
 113   bool IsFirstToken;
 114   std::stack<LexerState> StateStack;
 115   unsigned Column;
 116   unsigned TrailingWhitespace;
 117   std::unique_ptr<Lexer> Lex;
 118   LangOptions LangOpts;
 119   const SourceManager &SourceMgr;
 120   FileID ID;
 121   const FormatStyle &Style;
 122   IdentifierTable &IdentTable;
 123   AdditionalKeywords Keywords;
 124   encoding::Encoding Encoding;
 125   llvm::SpecificBumpPtrAllocator<FormatToken> &Allocator;
 126   // Index (in 'Tokens') of the last token that starts a new line.
 127   unsigned FirstInLineIndex;
 128   SmallVector<FormatToken *, 16> Tokens;
 129
 130   llvm::SmallMapVector<IdentifierInfo *, TokenType, 8> Macros;
 131
 132   llvm::SmallPtrSet<IdentifierInfo *, 8> TemplateNames, TypeNames;
 133
 134   bool FormattingDisabled;
 135
 136   llvm::Regex MacroBlockBeginRegex;
 137   llvm::Regex MacroBlockEndRegex;
 138
 139   // Targets that may appear inside a C# attribute.
 140   static const llvm::StringSet<> CSharpAttributeTargets;
 141
 142   /// Handle Verilog-specific tokens.
 143   bool readRawTokenVerilogSpecific(Token &Tok);
 144
 145   void readRawToken(FormatToken &Tok);
 146
 147   void resetLexer(unsigned Offset);
 148 };
 149
 150 } // namespace format
 151 } // namespace clang
 152
 153 #endif