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: 40 WhitespaceManager(SourceManager &SourceMgr, const FormatStyle &Style, 41 bool UseCRLF) 42 : SourceMgr(SourceMgr), Style(Style), UseCRLF(UseCRLF) {} 43 44 /// \brief Prepares the \c WhitespaceManager for another run. 45 void reset(); 46 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); 53 54 /// \brief Adds information about an unchangeable token's whitespace. 55 /// 56 /// Needs to be called for every token for which \c replaceWhitespace 57 /// was not called. 58 void addUntouchableToken(const FormatToken &Tok, bool InPPDirective); 59 60 /// \brief Inserts or replaces whitespace in the middle of a token. 61 /// 62 /// Inserts \p PreviousPostfix, \p Newlines, \p Spaces and \p CurrentPrefix 63 /// (in this order) at \p Offset inside \p Tok, replacing \p ReplaceChars 64 /// characters. 65 /// 66 /// Note: \p Spaces can be negative to retain information about initial 67 /// relative column offset between a line of a block comment and the start of 68 /// the comment. This negative offset may be compensated by trailing comment 69 /// alignment here. In all other cases negative \p Spaces will be truncated to 70 /// 0. 71 /// 72 /// When \p InPPDirective is true, escaped newlines are inserted. \p Spaces is 73 /// used to align backslashes correctly. 74 void replaceWhitespaceInToken(const FormatToken &Tok, unsigned Offset, 75 unsigned ReplaceChars, 76 StringRef PreviousPostfix, 77 StringRef CurrentPrefix, bool InPPDirective, 78 unsigned Newlines, unsigned IndentLevel, 79 int Spaces); 80 81 /// \brief Returns all the \c Replacements created during formatting. 82 const tooling::Replacements &generateReplacements(); 83 84 private: 85 /// \brief Represents a change before a token, a break inside a token, 86 /// or the layout of an unchanged token (or whitespace within). 87 struct Change { 88 /// \brief Functor to sort changes in original source order. 89 class IsBeforeInFile { 90 public: 91 IsBeforeInFile(const SourceManager &SourceMgr) : SourceMgr(SourceMgr) {} 92 bool operator()(const Change &C1, const Change &C2) const; 93 94 private: 95 const SourceManager &SourceMgr; 96 }; 97 98 Change() {} 99 100 /// \brief Creates a \c Change. 101 /// 102 /// The generated \c Change will replace the characters at 103 /// \p OriginalWhitespaceRange with a concatenation of 104 /// \p PreviousLinePostfix, \p NewlinesBefore line breaks, \p Spaces spaces 105 /// and \p CurrentLinePrefix. 106 /// 107 /// \p StartOfTokenColumn and \p InPPDirective will be used to lay out 108 /// trailing comments and escaped newlines. 109 Change(bool CreateReplacement, const SourceRange &OriginalWhitespaceRange, 110 unsigned IndentLevel, int Spaces, unsigned StartOfTokenColumn, 111 unsigned NewlinesBefore, StringRef PreviousLinePostfix, 112 StringRef CurrentLinePrefix, tok::TokenKind Kind, 113 bool ContinuesPPDirective); 114 115 bool CreateReplacement; 116 // Changes might be in the middle of a token, so we cannot just keep the 117 // FormatToken around to query its information. 118 SourceRange OriginalWhitespaceRange; 119 unsigned StartOfTokenColumn; 120 unsigned NewlinesBefore; 121 std::string PreviousLinePostfix; 122 std::string CurrentLinePrefix; 123 // The kind of the token whose whitespace this change replaces, or in which 124 // this change inserts whitespace. 125 // FIXME: Currently this is not set correctly for breaks inside comments, as 126 // the \c BreakableToken is still doing its own alignment. 127 tok::TokenKind Kind; 128 bool ContinuesPPDirective; 129 130 // The number of nested blocks the token is in. This is used to add tabs 131 // only for the indentation, and not for alignment, when 132 // UseTab = US_ForIndentation. 133 unsigned IndentLevel; 134 135 // The number of spaces in front of the token or broken part of the token. 136 // This will be adapted when aligning tokens. 137 // Can be negative to retain information about the initial relative offset 138 // of the lines in a block comment. This is used when aligning trailing 139 // comments. Uncompensated negative offset is truncated to 0. 140 int Spaces; 141 142 // \c IsTrailingComment, \c TokenLength, \c PreviousEndOfTokenColumn and 143 // \c EscapedNewlineColumn will be calculated in 144 // \c calculateLineBreakInformation. 145 bool IsTrailingComment; 146 unsigned TokenLength; 147 unsigned PreviousEndOfTokenColumn; 148 unsigned EscapedNewlineColumn; 149 150 // These fields are used to retain correct relative line indentation in a 151 // block comment when aligning trailing comments. 152 // 153 // If this Change represents a continuation of a block comment, 154 // \c StartOfBlockComment is pointer to the first Change in the block 155 // comment. \c IndentationOffset is a relative column offset to this 156 // change, so that the correct column can be reconstructed at the end of 157 // the alignment process. 158 const Change *StartOfBlockComment; 159 int IndentationOffset; 160 }; 161 162 /// \brief Calculate \c IsTrailingComment, \c TokenLength for the last tokens 163 /// or token parts in a line and \c PreviousEndOfTokenColumn and 164 /// \c EscapedNewlineColumn for the first tokens or token parts in a line. 165 void calculateLineBreakInformation(); 166 167 /// \brief Align trailing comments over all \c Changes. 168 void alignTrailingComments(); 169 170 /// \brief Align trailing comments from change \p Start to change \p End at 171 /// the specified \p Column. 172 void alignTrailingComments(unsigned Start, unsigned End, unsigned Column); 173 174 /// \brief Align escaped newlines over all \c Changes. 175 void alignEscapedNewlines(); 176 177 /// \brief Align escaped newlines from change \p Start to change \p End at 178 /// the specified \p Column. 179 void alignEscapedNewlines(unsigned Start, unsigned End, unsigned Column); 180 181 /// \brief Fill \c Replaces with the replacements for all effective changes. 182 void generateChanges(); 183 184 /// \brief Stores \p Text as the replacement for the whitespace in \p Range. 185 void storeReplacement(const SourceRange &Range, StringRef Text); 186 void appendNewlineText(std::string &Text, unsigned Newlines); 187 void appendNewlineText(std::string &Text, unsigned Newlines, 188 unsigned PreviousEndOfTokenColumn, 189 unsigned EscapedNewlineColumn); 190 void appendIndentText(std::string &Text, unsigned IndentLevel, 191 unsigned Spaces, unsigned WhitespaceStartColumn); 192 193 SmallVector<Change, 16> Changes; 194 SourceManager &SourceMgr; 195 tooling::Replacements Replaces; 196 const FormatStyle &Style; 197 bool UseCRLF; 198 }; 199 200 } // namespace format 201 } // namespace clang 202 203 #endif // LLVM_CLANG_FORMAT_WHITESPACEMANAGER_H 204
