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