xref: /freebsd/contrib/llvm-project/clang/lib/Format/FormatTokenLexer.h (revision 4b50c451720d8b427757a6da1dd2bb4c52cd9e35)
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 "clang/Basic/SourceLocation.h"
21 #include "clang/Basic/SourceManager.h"
22 #include "clang/Format/Format.h"
23 #include "llvm/ADT/MapVector.h"
24 #include "llvm/Support/Regex.h"
25 
26 #include <stack>
27 
28 namespace clang {
29 namespace format {
30 
31 enum LexerState {
32   NORMAL,
33   TEMPLATE_STRING,
34   TOKEN_STASHED,
35 };
36 
37 class FormatTokenLexer {
38 public:
39   FormatTokenLexer(const SourceManager &SourceMgr, FileID ID, unsigned Column,
40                    const FormatStyle &Style, encoding::Encoding Encoding);
41 
42   ArrayRef<FormatToken *> lex();
43 
44   const AdditionalKeywords &getKeywords() { return Keywords; }
45 
46 private:
47   void tryMergePreviousTokens();
48 
49   bool tryMergeLessLess();
50   bool tryMergeNSStringLiteral();
51   bool tryMergeJSPrivateIdentifier();
52   bool tryMergeCSharpVerbatimStringLiteral();
53   bool tryMergeCSharpKeywordVariables();
54   bool tryMergeCSharpNullConditionals();
55   bool tryMergeCSharpDoubleQuestion();
56 
57   bool tryMergeTokens(ArrayRef<tok::TokenKind> Kinds, TokenType NewType);
58 
59   // Returns \c true if \p Tok can only be followed by an operand in JavaScript.
60   bool precedesOperand(FormatToken *Tok);
61 
62   bool canPrecedeRegexLiteral(FormatToken *Prev);
63 
64   // Tries to parse a JavaScript Regex literal starting at the current token,
65   // if that begins with a slash and is in a location where JavaScript allows
66   // regex literals. Changes the current token to a regex literal and updates
67   // its text if successful.
68   void tryParseJSRegexLiteral();
69 
70   // Handles JavaScript template strings.
71   //
72   // JavaScript template strings use backticks ('`') as delimiters, and allow
73   // embedding expressions nested in ${expr-here}. Template strings can be
74   // nested recursively, i.e. expressions can contain template strings in turn.
75   //
76   // The code below parses starting from a backtick, up to a closing backtick or
77   // an opening ${. It also maintains a stack of lexing contexts to handle
78   // nested template parts by balancing curly braces.
79   void handleTemplateStrings();
80 
81   void tryParsePythonComment();
82 
83   bool tryMerge_TMacro();
84 
85   bool tryMergeConflictMarkers();
86 
87   FormatToken *getStashedToken();
88 
89   FormatToken *getNextToken();
90 
91   FormatToken *FormatTok;
92   bool IsFirstToken;
93   std::stack<LexerState> StateStack;
94   unsigned Column;
95   unsigned TrailingWhitespace;
96   std::unique_ptr<Lexer> Lex;
97   const SourceManager &SourceMgr;
98   FileID ID;
99   const FormatStyle &Style;
100   IdentifierTable IdentTable;
101   AdditionalKeywords Keywords;
102   encoding::Encoding Encoding;
103   llvm::SpecificBumpPtrAllocator<FormatToken> Allocator;
104   // Index (in 'Tokens') of the last token that starts a new line.
105   unsigned FirstInLineIndex;
106   SmallVector<FormatToken *, 16> Tokens;
107 
108   llvm::SmallMapVector<IdentifierInfo *, TokenType, 8> Macros;
109 
110   bool FormattingDisabled;
111 
112   llvm::Regex MacroBlockBeginRegex;
113   llvm::Regex MacroBlockEndRegex;
114 
115   void readRawToken(FormatToken &Tok);
116 
117   void resetLexer(unsigned Offset);
118 };
119 
120 } // namespace format
121 } // namespace clang
122 
123 #endif
124