WhitespaceManager.h revision 70ce7881fc30a39b795b2873f008e7eca72ba669 
1//===--- WhitespaceManager.h - Format C++ code ----------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9///
10/// \file
11/// \brief WhitespaceManager class manages whitespace around tokens and their
12/// replacements.
13///
14//===----------------------------------------------------------------------===//
15
16#ifndef LLVM_CLANG_FORMAT_WHITESPACEMANAGER_H
17#define LLVM_CLANG_FORMAT_WHITESPACEMANAGER_H
18
19#include "TokenAnnotator.h"
20#include "clang/Basic/SourceManager.h"
21#include "clang/Format/Format.h"
22#include <string>
23
24namespace clang {
25namespace format {
26
27/// \brief Manages the whitespaces around tokens and their replacements.
28///
29/// This includes special handling for certain constructs, e.g. the alignment of
30/// trailing line comments.
31class WhitespaceManager {
32public:
33  WhitespaceManager(SourceManager &SourceMgr, const FormatStyle &Style)
34      : SourceMgr(SourceMgr), Style(Style) {}
35
36  /// \brief Replaces the whitespace in front of \p Tok. Only call once for
37  /// each \c AnnotatedToken.
38  void replaceWhitespace(const AnnotatedToken &Tok, unsigned NewLines,
39                         unsigned Spaces, unsigned WhitespaceStartColumn);
40
41  /// \brief Like \c replaceWhitespace, but additionally adds right-aligned
42  /// backslashes to escape newlines inside a preprocessor directive.
43  ///
44  /// This function and \c replaceWhitespace have the same behavior if
45  /// \c Newlines == 0.
46  void replacePPWhitespace(const AnnotatedToken &Tok, unsigned NewLines,
47                           unsigned Spaces, unsigned WhitespaceStartColumn);
48
49  /// \brief Inserts a line break into the middle of a token.
50  ///
51  /// Will break at \p Offset inside \p Tok, putting \p Prefix before the line
52  /// break and \p Postfix before the rest of the token starts in the next line.
53  ///
54  /// \p InPPDirective, \p Spaces, \p WhitespaceStartColumn and \p Style are
55  /// used to generate the correct line break.
56  void breakToken(const FormatToken &Tok, unsigned Offset,
57                  unsigned ReplaceChars, StringRef Prefix, StringRef Postfix,
58                  bool InPPDirective, unsigned Spaces,
59                  unsigned WhitespaceStartColumn);
60
61  /// \brief Returns all the \c Replacements created during formatting.
62  const tooling::Replacements &generateReplacements();
63
64  void addReplacement(const SourceLocation &SourceLoc, unsigned ReplaceChars,
65                      StringRef Text);
66
67  void addUntouchableComment(unsigned Column);
68
69private:
70  static StringRef getLineCommentPrefix(StringRef Comment);
71
72  /// \brief Splits one line in a line comment, if it doesn't fit to
73  /// provided column limit. Removes trailing whitespace in each line.
74  ///
75  /// \param Line points to the line contents without leading // or /*.
76  ///
77  /// \param StartColumn is the column where the first character of Line will be
78  /// located after formatting.
79  ///
80  /// \param LinePrefix is inserted after each line break.
81  void splitLineComment(const FormatToken &Tok, StringRef Line,
82                        size_t StartColumn, StringRef LinePrefix,
83                        const char *WhiteSpaceChars = " ");
84
85  std::string getNewLineText(unsigned NewLines, unsigned Spaces);
86
87  std::string getNewLineText(unsigned NewLines, unsigned Spaces,
88                             unsigned WhitespaceStartColumn);
89
90  /// \brief Structure to store a comment for later layout and alignment.
91  struct StoredComment {
92    FormatToken Tok;
93    unsigned MinColumn;
94    unsigned MaxColumn;
95    unsigned NewLines;
96    unsigned Spaces;
97    bool Untouchable;
98  };
99  SmallVector<StoredComment, 16> Comments;
100  typedef SmallVector<StoredComment, 16>::iterator comment_iterator;
101
102  /// \brief Try to align all stashed comments.
103  void alignComments();
104
105  /// \brief Put all the comments between \p I and \p E into \p Column.
106  void alignComments(comment_iterator I, comment_iterator E, unsigned Column);
107
108  /// \brief Stores \p Text as the replacement for the whitespace in front of
109  /// \p Tok.
110  void storeReplacement(const FormatToken &Tok, const std::string Text);
111
112  SourceManager &SourceMgr;
113  tooling::Replacements Replaces;
114  const FormatStyle &Style;
115};
116
117} // namespace format
118} // namespace clang
119
120#endif // LLVM_CLANG_FORMAT_WHITESPACEMANAGER_H
121