1 //===--- WhitespaceManager.h - Format C++ code ------------------*- C++ -*-===// 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 24 namespace clang { 25 namespace 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. 31 /// 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. 36 /// 37 /// There may be multiple calls to \c breakToken for a given token. 38 class WhitespaceManager { 39 public: WhitespaceManager(SourceManager & SourceMgr,const FormatStyle & Style)40 WhitespaceManager(SourceManager &SourceMgr, const FormatStyle &Style) 41 : SourceMgr(SourceMgr), Style(Style) {} 42 43 /// \brief Replaces the whitespace in front of \p Tok. Only call once for 44 /// each \c AnnotatedToken. 45 void replaceWhitespace(const FormatToken &Tok, unsigned Newlines, 46 unsigned Spaces, unsigned StartOfTokenColumn, 47 bool InPPDirective = false); 48 49 /// \brief Adds information about an unchangable token's whitespace. 50 /// 51 /// Needs to be called for every token for which \c replaceWhitespace 52 /// was not called. 53 void addUntouchableToken(const FormatToken &Tok, bool InPPDirective); 54 55 /// \brief Inserts or replaces whitespace in the middle of a token. 56 /// 57 /// Inserts \p PreviousPostfix, \p Newlines, \p Spaces and \p CurrentPrefix 58 /// (in this order) at \p Offset inside \p Tok, replacing \p ReplaceChars 59 /// characters. 60 /// 61 /// When \p InPPDirective is true, escaped newlines are inserted. \p Spaces is 62 /// used to align backslashes correctly. 63 void replaceWhitespaceInToken(const FormatToken &Tok, unsigned Offset, 64 unsigned ReplaceChars, 65 StringRef PreviousPostfix, 66 StringRef CurrentPrefix, bool InPPDirective, 67 unsigned Newlines, unsigned Spaces); 68 69 /// \brief Returns all the \c Replacements created during formatting. 70 const tooling::Replacements &generateReplacements(); 71 72 private: 73 /// \brief Represents a change before a token, a break inside a token, 74 /// or the layout of an unchanged token (or whitespace within). 75 struct Change { 76 /// \brief Functor to sort changes in original source order. 77 class IsBeforeInFile { 78 public: IsBeforeInFileChange79 IsBeforeInFile(const SourceManager &SourceMgr) : SourceMgr(SourceMgr) {} 80 bool operator()(const Change &C1, const Change &C2) const; 81 82 private: 83 const SourceManager &SourceMgr; 84 }; 85 ChangeChange86 Change() {} 87 88 /// \brief Creates a \c Change. 89 /// 90 /// The generated \c Change will replace the characters at 91 /// \p OriginalWhitespaceRange with a concatenation of 92 /// \p PreviousLinePostfix, \p NewlinesBefore line breaks, \p Spaces spaces 93 /// and \p CurrentLinePrefix. 94 /// 95 /// \p StartOfTokenColumn and \p InPPDirective will be used to lay out 96 /// trailing comments and escaped newlines. 97 Change(bool CreateReplacement, const SourceRange &OriginalWhitespaceRange, 98 unsigned Spaces, unsigned StartOfTokenColumn, 99 unsigned NewlinesBefore, StringRef PreviousLinePostfix, 100 StringRef CurrentLinePrefix, tok::TokenKind Kind, 101 bool ContinuesPPDirective); 102 103 bool CreateReplacement; 104 // Changes might be in the middle of a token, so we cannot just keep the 105 // FormatToken around to query its information. 106 SourceRange OriginalWhitespaceRange; 107 unsigned StartOfTokenColumn; 108 unsigned NewlinesBefore; 109 std::string PreviousLinePostfix; 110 std::string CurrentLinePrefix; 111 // The kind of the token whose whitespace this change replaces, or in which 112 // this change inserts whitespace. 113 // FIXME: Currently this is not set correctly for breaks inside comments, as 114 // the \c BreakableToken is still doing its own alignment. 115 tok::TokenKind Kind; 116 bool ContinuesPPDirective; 117 118 // The number of spaces in front of the token or broken part of the token. 119 // This will be adapted when aligning tokens. 120 unsigned Spaces; 121 122 // \c IsTrailingComment, \c TokenLength, \c PreviousEndOfTokenColumn and 123 // \c EscapedNewlineColumn will be calculated in 124 // \c calculateLineBreakInformation. 125 bool IsTrailingComment; 126 unsigned TokenLength; 127 unsigned PreviousEndOfTokenColumn; 128 unsigned EscapedNewlineColumn; 129 }; 130 131 /// \brief Calculate \c IsTrailingComment, \c TokenLength for the last tokens 132 /// or token parts in a line and \c PreviousEndOfTokenColumn and 133 /// \c EscapedNewlineColumn for the first tokens or token parts in a line. 134 void calculateLineBreakInformation(); 135 136 /// \brief Align trailing comments over all \c Changes. 137 void alignTrailingComments(); 138 139 /// \brief Align trailing comments from change \p Start to change \p End at 140 /// the specified \p Column. 141 void alignTrailingComments(unsigned Start, unsigned End, unsigned Column); 142 143 /// \brief Align escaped newlines over all \c Changes. 144 void alignEscapedNewlines(); 145 146 /// \brief Align escaped newlines from change \p Start to change \p End at 147 /// the specified \p Column. 148 void alignEscapedNewlines(unsigned Start, unsigned End, unsigned Column); 149 150 /// \brief Fill \c Replaces with the replacements for all effective changes. 151 void generateChanges(); 152 153 /// \brief Stores \p Text as the replacement for the whitespace in \p Range. 154 void storeReplacement(const SourceRange &Range, StringRef Text); 155 std::string getNewlineText(unsigned Newlines, unsigned Spaces); 156 std::string getNewlineText(unsigned Newlines, unsigned Spaces, 157 unsigned PreviousEndOfTokenColumn, 158 unsigned EscapedNewlineColumn); 159 std::string getIndentText(unsigned Spaces); 160 161 SmallVector<Change, 16> Changes; 162 SourceManager &SourceMgr; 163 tooling::Replacements Replaces; 164 const FormatStyle &Style; 165 }; 166 167 } // namespace format 168 } // namespace clang 169 170 #endif // LLVM_CLANG_FORMAT_WHITESPACEMANAGER_H 171