xref: /freebsd/contrib/llvm-project/clang/lib/Format/FormatTokenLexer.h (revision 700637cbb5e582861067a11aaca4d053546871d2)
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 
getKeywords()44   const AdditionalKeywords &getKeywords() { return Keywords; }
45 
46 private:
47   void tryMergePreviousTokens();
48 
49   bool tryMergeLessLess();
50   bool tryMergeGreaterGreater();
51   bool tryMergeUserDefinedLiteral();
52   bool tryMergeNSStringLiteral();
53   bool tryMergeJSPrivateIdentifier();
54   bool tryMergeCSharpStringLiteral();
55   bool tryMergeCSharpKeywordVariables();
56   bool tryMergeNullishCoalescingEqual();
57   bool tryTransformCSharpForEach();
58   bool tryMergeForEach();
59   bool tryTransformTryUsageForC();
60 
61   // Merge the most recently lexed tokens into a single token if their kinds are
62   // correct.
63   bool tryMergeTokens(ArrayRef<tok::TokenKind> Kinds, TokenType NewType);
64   // Merge without checking their kinds.
65   bool tryMergeTokens(size_t Count, TokenType NewType);
66   // Merge if their kinds match any one of Kinds.
67   bool tryMergeTokensAny(ArrayRef<ArrayRef<tok::TokenKind>> Kinds,
68                          TokenType NewType);
69 
70   // Returns \c true if \p Tok can only be followed by an operand in JavaScript.
71   bool precedesOperand(FormatToken *Tok);
72 
73   bool canPrecedeRegexLiteral(FormatToken *Prev);
74 
75   void tryParseJavaTextBlock();
76 
77   // Tries to parse a JavaScript Regex literal starting at the current token,
78   // if that begins with a slash and is in a location where JavaScript allows
79   // regex literals. Changes the current token to a regex literal and updates
80   // its text if successful.
81   void tryParseJSRegexLiteral();
82 
83   // Handles JavaScript template strings.
84   //
85   // JavaScript template strings use backticks ('`') as delimiters, and allow
86   // embedding expressions nested in ${expr-here}. Template strings can be
87   // nested recursively, i.e. expressions can contain template strings in turn.
88   //
89   // The code below parses starting from a backtick, up to a closing backtick or
90   // an opening ${. It also maintains a stack of lexing contexts to handle
91   // nested template parts by balancing curly braces.
92   void handleTemplateStrings();
93 
94   void handleCSharpVerbatimAndInterpolatedStrings();
95 
96   // Handles TableGen multiline strings. It has the form [{ ... }].
97   void handleTableGenMultilineString();
98   // Handles TableGen numeric like identifiers.
99   // They have a forms of [0-9]*[_a-zA-Z]([_a-zA-Z0-9]*). But limited to the
100   // case it is not lexed as an integer.
101   void handleTableGenNumericLikeIdentifier();
102 
103   void tryParsePythonComment();
104 
105   bool tryMerge_TMacro();
106 
107   bool tryMergeConflictMarkers();
108 
109   void truncateToken(size_t NewLen);
110 
111   FormatToken *getStashedToken();
112 
113   FormatToken *getNextToken();
114 
115   FormatToken *FormatTok;
116   bool IsFirstToken;
117   std::stack<LexerState> StateStack;
118   unsigned Column;
119   unsigned TrailingWhitespace;
120   std::unique_ptr<Lexer> Lex;
121   LangOptions LangOpts;
122   const SourceManager &SourceMgr;
123   FileID ID;
124   const FormatStyle &Style;
125   IdentifierTable &IdentTable;
126   AdditionalKeywords Keywords;
127   encoding::Encoding Encoding;
128   llvm::SpecificBumpPtrAllocator<FormatToken> &Allocator;
129   // Index (in 'Tokens') of the last token that starts a new line.
130   unsigned FirstInLineIndex;
131   SmallVector<FormatToken *, 16> Tokens;
132 
133   llvm::SmallMapVector<IdentifierInfo *, TokenType, 8> Macros;
134 
135   llvm::SmallPtrSet<IdentifierInfo *, 8> MacrosSkippedByRemoveParentheses,
136       TemplateNames, TypeNames, VariableTemplates;
137 
138   bool FormattingDisabled;
139   llvm::Regex FormatOffRegex; // For one line.
140 
141   llvm::Regex MacroBlockBeginRegex;
142   llvm::Regex MacroBlockEndRegex;
143 
144   // Targets that may appear inside a C# attribute.
145   static const llvm::StringSet<> CSharpAttributeTargets;
146 
147   /// Handle Verilog-specific tokens.
148   bool readRawTokenVerilogSpecific(Token &Tok);
149 
150   void readRawToken(FormatToken &Tok);
151 
152   void resetLexer(unsigned Offset);
153 };
154 
155 } // namespace format
156 } // namespace clang
157 
158 #endif
159