1 //===--- WhitespaceManager.h - Format C++ code ------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
11 /// \brief WhitespaceManager class manages whitespace around tokens and their
14 //===----------------------------------------------------------------------===//
16 #ifndef LLVM_CLANG_FORMAT_WHITESPACEMANAGER_H
17 #define LLVM_CLANG_FORMAT_WHITESPACEMANAGER_H
19 #include "TokenAnnotator.h"
20 #include "clang/Basic/SourceManager.h"
21 #include "clang/Format/Format.h"
27 /// \brief Manages the whitespaces around tokens and their replacements.
29 /// This includes special handling for certain constructs, e.g. the alignment of
30 /// trailing line comments.
32 /// To guarantee correctness of alignment operations, the \c WhitespaceManager
33 /// must be informed about every token in the source file; for each token, there
34 /// must be exactly one call to either \c replaceWhitespace or
35 /// \c addUntouchableToken.
37 /// There may be multiple calls to \c breakToken for a given token.
38 class WhitespaceManager {
40 WhitespaceManager(SourceManager &SourceMgr, const FormatStyle &Style,
42 : SourceMgr(SourceMgr), Style(Style), UseCRLF(UseCRLF) {}
44 /// \brief Prepares the \c WhitespaceManager for another run.
47 /// \brief Replaces the whitespace in front of \p Tok. Only call once for
48 /// each \c AnnotatedToken.
49 void replaceWhitespace(FormatToken &Tok, unsigned Newlines,
50 unsigned IndentLevel, unsigned Spaces,
51 unsigned StartOfTokenColumn,
52 bool InPPDirective = false);
54 /// \brief Adds information about an unchangable token's whitespace.
56 /// Needs to be called for every token for which \c replaceWhitespace
58 void addUntouchableToken(const FormatToken &Tok, bool InPPDirective);
60 /// \brief Inserts or replaces whitespace in the middle of a token.
62 /// Inserts \p PreviousPostfix, \p Newlines, \p Spaces and \p CurrentPrefix
63 /// (in this order) at \p Offset inside \p Tok, replacing \p ReplaceChars
66 /// When \p InPPDirective is true, escaped newlines are inserted. \p Spaces is
67 /// used to align backslashes correctly.
68 void replaceWhitespaceInToken(const FormatToken &Tok, unsigned Offset,
69 unsigned ReplaceChars,
70 StringRef PreviousPostfix,
71 StringRef CurrentPrefix, bool InPPDirective,
72 unsigned Newlines, unsigned IndentLevel,
75 /// \brief Returns all the \c Replacements created during formatting.
76 const tooling::Replacements &generateReplacements();
79 /// \brief Represents a change before a token, a break inside a token,
80 /// or the layout of an unchanged token (or whitespace within).
82 /// \brief Functor to sort changes in original source order.
83 class IsBeforeInFile {
85 IsBeforeInFile(const SourceManager &SourceMgr) : SourceMgr(SourceMgr) {}
86 bool operator()(const Change &C1, const Change &C2) const;
89 const SourceManager &SourceMgr;
94 /// \brief Creates a \c Change.
96 /// The generated \c Change will replace the characters at
97 /// \p OriginalWhitespaceRange with a concatenation of
98 /// \p PreviousLinePostfix, \p NewlinesBefore line breaks, \p Spaces spaces
99 /// and \p CurrentLinePrefix.
101 /// \p StartOfTokenColumn and \p InPPDirective will be used to lay out
102 /// trailing comments and escaped newlines.
103 Change(bool CreateReplacement, const SourceRange &OriginalWhitespaceRange,
104 unsigned IndentLevel, unsigned Spaces, unsigned StartOfTokenColumn,
105 unsigned NewlinesBefore, StringRef PreviousLinePostfix,
106 StringRef CurrentLinePrefix, tok::TokenKind Kind,
107 bool ContinuesPPDirective);
109 bool CreateReplacement;
110 // Changes might be in the middle of a token, so we cannot just keep the
111 // FormatToken around to query its information.
112 SourceRange OriginalWhitespaceRange;
113 unsigned StartOfTokenColumn;
114 unsigned NewlinesBefore;
115 std::string PreviousLinePostfix;
116 std::string CurrentLinePrefix;
117 // The kind of the token whose whitespace this change replaces, or in which
118 // this change inserts whitespace.
119 // FIXME: Currently this is not set correctly for breaks inside comments, as
120 // the \c BreakableToken is still doing its own alignment.
122 bool ContinuesPPDirective;
124 // The number of nested blocks the token is in. This is used to add tabs
125 // only for the indentation, and not for alignment, when
126 // UseTab = US_ForIndentation.
127 unsigned IndentLevel;
129 // The number of spaces in front of the token or broken part of the token.
130 // This will be adapted when aligning tokens.
133 // \c IsTrailingComment, \c TokenLength, \c PreviousEndOfTokenColumn and
134 // \c EscapedNewlineColumn will be calculated in
135 // \c calculateLineBreakInformation.
136 bool IsTrailingComment;
137 unsigned TokenLength;
138 unsigned PreviousEndOfTokenColumn;
139 unsigned EscapedNewlineColumn;
142 /// \brief Calculate \c IsTrailingComment, \c TokenLength for the last tokens
143 /// or token parts in a line and \c PreviousEndOfTokenColumn and
144 /// \c EscapedNewlineColumn for the first tokens or token parts in a line.
145 void calculateLineBreakInformation();
147 /// \brief Align trailing comments over all \c Changes.
148 void alignTrailingComments();
150 /// \brief Align trailing comments from change \p Start to change \p End at
151 /// the specified \p Column.
152 void alignTrailingComments(unsigned Start, unsigned End, unsigned Column);
154 /// \brief Align escaped newlines over all \c Changes.
155 void alignEscapedNewlines();
157 /// \brief Align escaped newlines from change \p Start to change \p End at
158 /// the specified \p Column.
159 void alignEscapedNewlines(unsigned Start, unsigned End, unsigned Column);
161 /// \brief Fill \c Replaces with the replacements for all effective changes.
162 void generateChanges();
164 /// \brief Stores \p Text as the replacement for the whitespace in \p Range.
165 void storeReplacement(const SourceRange &Range, StringRef Text);
166 void appendNewlineText(std::string &Text, unsigned Newlines);
167 void appendNewlineText(std::string &Text, unsigned Newlines,
168 unsigned PreviousEndOfTokenColumn,
169 unsigned EscapedNewlineColumn);
170 void appendIndentText(std::string &Text, unsigned IndentLevel,
171 unsigned Spaces, unsigned WhitespaceStartColumn);
173 SmallVector<Change, 16> Changes;
174 SourceManager &SourceMgr;
175 tooling::Replacements Replaces;
176 const FormatStyle &Style;
180 } // namespace format
183 #endif // LLVM_CLANG_FORMAT_WHITESPACEMANAGER_H