clang  15.0.0git
WhitespaceManager.h
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1 //===--- WhitespaceManager.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 /// WhitespaceManager class manages whitespace around tokens and their
11 /// replacements.
12 ///
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_CLANG_LIB_FORMAT_WHITESPACEMANAGER_H
16 #define LLVM_CLANG_LIB_FORMAT_WHITESPACEMANAGER_H
17 
18 #include "TokenAnnotator.h"
20 #include "clang/Format/Format.h"
21 #include "llvm/ADT/SmallVector.h"
22 #include <algorithm>
23 #include <string>
24 #include <tuple>
25 
26 namespace clang {
27 namespace format {
28 
29 /// Manages the whitespaces around tokens and their replacements.
30 ///
31 /// This includes special handling for certain constructs, e.g. the alignment of
32 /// trailing line comments.
33 ///
34 /// To guarantee correctness of alignment operations, the \c WhitespaceManager
35 /// must be informed about every token in the source file; for each token, there
36 /// must be exactly one call to either \c replaceWhitespace or
37 /// \c addUntouchableToken.
38 ///
39 /// There may be multiple calls to \c breakToken for a given token.
41 public:
42  WhitespaceManager(const SourceManager &SourceMgr, const FormatStyle &Style,
43  bool UseCRLF)
44  : SourceMgr(SourceMgr), Style(Style), UseCRLF(UseCRLF) {}
45 
46  bool useCRLF() const { return UseCRLF; }
47 
48  /// Infers whether the input is using CRLF.
49  static bool inputUsesCRLF(StringRef Text, bool DefaultToCRLF);
50 
51  /// Replaces the whitespace in front of \p Tok. Only call once for
52  /// each \c AnnotatedToken.
53  ///
54  /// \p StartOfTokenColumn is the column at which the token will start after
55  /// this replacement. It is needed for determining how \p Spaces is turned
56  /// into tabs and spaces for some format styles.
57  void replaceWhitespace(FormatToken &Tok, unsigned Newlines, unsigned Spaces,
58  unsigned StartOfTokenColumn, bool isAligned = false,
59  bool InPPDirective = false);
60 
61  /// Adds information about an unchangeable token's whitespace.
62  ///
63  /// Needs to be called for every token for which \c replaceWhitespace
64  /// was not called.
65  void addUntouchableToken(const FormatToken &Tok, bool InPPDirective);
66 
67  llvm::Error addReplacement(const tooling::Replacement &Replacement);
68 
69  /// Inserts or replaces whitespace in the middle of a token.
70  ///
71  /// Inserts \p PreviousPostfix, \p Newlines, \p Spaces and \p CurrentPrefix
72  /// (in this order) at \p Offset inside \p Tok, replacing \p ReplaceChars
73  /// characters.
74  ///
75  /// Note: \p Spaces can be negative to retain information about initial
76  /// relative column offset between a line of a block comment and the start of
77  /// the comment. This negative offset may be compensated by trailing comment
78  /// alignment here. In all other cases negative \p Spaces will be truncated to
79  /// 0.
80  ///
81  /// When \p InPPDirective is true, escaped newlines are inserted. \p Spaces is
82  /// used to align backslashes correctly.
83  void replaceWhitespaceInToken(const FormatToken &Tok, unsigned Offset,
84  unsigned ReplaceChars,
85  StringRef PreviousPostfix,
86  StringRef CurrentPrefix, bool InPPDirective,
87  unsigned Newlines, int Spaces);
88 
89  /// Returns all the \c Replacements created during formatting.
91 
92  /// Represents a change before a token, a break inside a token,
93  /// or the layout of an unchanged token (or whitespace within).
94  struct Change {
95  /// Functor to sort changes in original source order.
97  public:
98  IsBeforeInFile(const SourceManager &SourceMgr) : SourceMgr(SourceMgr) {}
99  bool operator()(const Change &C1, const Change &C2) const;
100 
101  private:
102  const SourceManager &SourceMgr;
103  };
104 
105  /// Creates a \c Change.
106  ///
107  /// The generated \c Change will replace the characters at
108  /// \p OriginalWhitespaceRange with a concatenation of
109  /// \p PreviousLinePostfix, \p NewlinesBefore line breaks, \p Spaces spaces
110  /// and \p CurrentLinePrefix.
111  ///
112  /// \p StartOfTokenColumn and \p InPPDirective will be used to lay out
113  /// trailing comments and escaped newlines.
116  unsigned StartOfTokenColumn, unsigned NewlinesBefore,
117  StringRef PreviousLinePostfix, StringRef CurrentLinePrefix,
118  bool IsAligned, bool ContinuesPPDirective, bool IsInsideToken);
119 
120  // The kind of the token whose whitespace this change replaces, or in which
121  // this change inserts whitespace.
122  // FIXME: Currently this is not set correctly for breaks inside comments, as
123  // the \c BreakableToken is still doing its own alignment.
124  const FormatToken *Tok;
125 
127  // Changes might be in the middle of a token, so we cannot just keep the
128  // FormatToken around to query its information.
131  unsigned NewlinesBefore;
134  bool IsAligned;
136 
137  // The number of spaces in front of the token or broken part of the token.
138  // This will be adapted when aligning tokens.
139  // Can be negative to retain information about the initial relative offset
140  // of the lines in a block comment. This is used when aligning trailing
141  // comments. Uncompensated negative offset is truncated to 0.
142  int Spaces;
143 
144  // If this change is inside of a token but not at the start of the token or
145  // directly after a newline.
147 
148  // \c IsTrailingComment, \c TokenLength, \c PreviousEndOfTokenColumn and
149  // \c EscapedNewlineColumn will be calculated in
150  // \c calculateLineBreakInformation.
152  unsigned TokenLength;
155 
156  // These fields are used to retain correct relative line indentation in a
157  // block comment when aligning trailing comments.
158  //
159  // If this Change represents a continuation of a block comment,
160  // \c StartOfBlockComment is pointer to the first Change in the block
161  // comment. \c IndentationOffset is a relative column offset to this
162  // change, so that the correct column can be reconstructed at the end of
163  // the alignment process.
166 
167  // Depth of conditionals. Computed from tracking fake parenthesis, except
168  // it does not increase the indent for "chained" conditionals.
170 
171  // A combination of indent, nesting and conditionals levels, which are used
172  // in tandem to compute lexical scope, for the purposes of deciding
173  // when to stop consecutive alignment runs.
174  std::tuple<unsigned, unsigned, unsigned> indentAndNestingLevel() const {
175  return std::make_tuple(Tok->IndentLevel, Tok->NestingLevel,
177  }
178  };
179 
180 private:
181  struct CellDescription {
182  unsigned Index = 0;
183  unsigned Cell = 0;
184  unsigned EndIndex = 0;
185  bool HasSplit = false;
186  CellDescription *NextColumnElement = nullptr;
187 
188  constexpr bool operator==(const CellDescription &Other) const {
189  return Index == Other.Index && Cell == Other.Cell &&
190  EndIndex == Other.EndIndex;
191  }
192  constexpr bool operator!=(const CellDescription &Other) const {
193  return !(*this == Other);
194  }
195  };
196 
197  struct CellDescriptions {
198  SmallVector<CellDescription> Cells;
199  SmallVector<unsigned> CellCounts;
200  unsigned InitialSpaces = 0;
201 
202  // Determine if every row in the the array
203  // has the same number of columns.
204  bool isRectangular() const {
205  if (CellCounts.empty())
206  return false;
207 
208  for (auto NumberOfColumns : CellCounts)
209  if (NumberOfColumns != CellCounts[0])
210  return false;
211  return true;
212  }
213  };
214 
215  /// Calculate \c IsTrailingComment, \c TokenLength for the last tokens
216  /// or token parts in a line and \c PreviousEndOfTokenColumn and
217  /// \c EscapedNewlineColumn for the first tokens or token parts in a line.
218  void calculateLineBreakInformation();
219 
220  /// \brief Align consecutive C/C++ preprocessor macros over all \c Changes.
221  void alignConsecutiveMacros();
222 
223  /// Align consecutive assignments over all \c Changes.
224  void alignConsecutiveAssignments();
225 
226  /// Align consecutive bitfields over all \c Changes.
227  void alignConsecutiveBitFields();
228 
229  /// Align consecutive declarations over all \c Changes.
230  void alignConsecutiveDeclarations();
231 
232  /// Align consecutive declarations over all \c Changes.
233  void alignChainedConditionals();
234 
235  /// Align trailing comments over all \c Changes.
236  void alignTrailingComments();
237 
238  /// Align trailing comments from change \p Start to change \p End at
239  /// the specified \p Column.
240  void alignTrailingComments(unsigned Start, unsigned End, unsigned Column);
241 
242  /// Align escaped newlines over all \c Changes.
243  void alignEscapedNewlines();
244 
245  /// Align escaped newlines from change \p Start to change \p End at
246  /// the specified \p Column.
247  void alignEscapedNewlines(unsigned Start, unsigned End, unsigned Column);
248 
249  /// Align Array Initializers over all \c Changes.
250  void alignArrayInitializers();
251 
252  /// Align Array Initializers from change \p Start to change \p End at
253  /// the specified \p Column.
254  void alignArrayInitializers(unsigned Start, unsigned End);
255 
256  /// Align Array Initializers being careful to right justify the columns
257  /// as described by \p CellDescs.
258  void alignArrayInitializersRightJustified(CellDescriptions &&CellDescs);
259 
260  /// Align Array Initializers being careful to left justify the columns
261  /// as described by \p CellDescs.
262  void alignArrayInitializersLeftJustified(CellDescriptions &&CellDescs);
263 
264  /// Calculate the cell width between two indexes.
265  unsigned calculateCellWidth(unsigned Start, unsigned End,
266  bool WithSpaces = false) const;
267 
268  /// Get a set of fully specified CellDescriptions between \p Start and
269  /// \p End of the change list.
270  CellDescriptions getCells(unsigned Start, unsigned End);
271 
272  /// Does this \p Cell contain a split element?
273  static bool isSplitCell(const CellDescription &Cell);
274 
275  /// Get the width of the preceding cells from \p Start to \p End.
276  template <typename I>
277  auto getNetWidth(const I &Start, const I &End, unsigned InitialSpaces) const {
278  auto NetWidth = InitialSpaces;
279  for (auto PrevIter = Start; PrevIter != End; ++PrevIter) {
280  // If we broke the line the initial spaces are already
281  // accounted for.
282  if (Changes[PrevIter->Index].NewlinesBefore > 0)
283  NetWidth = 0;
284  NetWidth +=
285  calculateCellWidth(PrevIter->Index, PrevIter->EndIndex, true) + 1;
286  }
287  return NetWidth;
288  }
289 
290  /// Get the maximum width of a cell in a sequence of columns.
291  template <typename I>
292  unsigned getMaximumCellWidth(I CellIter, unsigned NetWidth) const {
293  unsigned CellWidth =
294  calculateCellWidth(CellIter->Index, CellIter->EndIndex, true);
295  if (Changes[CellIter->Index].NewlinesBefore == 0)
296  CellWidth += NetWidth;
297  for (const auto *Next = CellIter->NextColumnElement; Next != nullptr;
298  Next = Next->NextColumnElement) {
299  auto ThisWidth = calculateCellWidth(Next->Index, Next->EndIndex, true);
300  if (Changes[Next->Index].NewlinesBefore == 0)
301  ThisWidth += NetWidth;
302  CellWidth = std::max(CellWidth, ThisWidth);
303  }
304  return CellWidth;
305  }
306 
307  /// Get The maximum width of all columns to a given cell.
308  template <typename I>
309  unsigned getMaximumNetWidth(const I &CellStart, const I &CellStop,
310  unsigned InitialSpaces, unsigned CellCount,
311  unsigned MaxRowCount) const {
312  auto MaxNetWidth = getNetWidth(CellStart, CellStop, InitialSpaces);
313  auto RowCount = 1U;
314  auto Offset = std::distance(CellStart, CellStop);
315  for (const auto *Next = CellStop->NextColumnElement; Next != nullptr;
316  Next = Next->NextColumnElement) {
317  if (RowCount > MaxRowCount)
318  break;
319  auto Start = (CellStart + RowCount * CellCount);
320  auto End = Start + Offset;
321  MaxNetWidth =
322  std::max(MaxNetWidth, getNetWidth(Start, End, InitialSpaces));
323  ++RowCount;
324  }
325  return MaxNetWidth;
326  }
327 
328  /// Align a split cell with a newline to the first element in the cell.
329  void alignToStartOfCell(unsigned Start, unsigned End);
330 
331  /// Link the Cell pointers in the list of Cells.
332  static CellDescriptions linkCells(CellDescriptions &&CellDesc);
333 
334  /// Fill \c Replaces with the replacements for all effective changes.
335  void generateChanges();
336 
337  /// Stores \p Text as the replacement for the whitespace in \p Range.
338  void storeReplacement(SourceRange Range, StringRef Text);
339  void appendNewlineText(std::string &Text, unsigned Newlines);
340  void appendEscapedNewlineText(std::string &Text, unsigned Newlines,
341  unsigned PreviousEndOfTokenColumn,
342  unsigned EscapedNewlineColumn);
343  void appendIndentText(std::string &Text, unsigned IndentLevel,
344  unsigned Spaces, unsigned WhitespaceStartColumn,
345  bool IsAligned);
346  unsigned appendTabIndent(std::string &Text, unsigned Spaces,
347  unsigned Indentation);
348 
349  SmallVector<Change, 16> Changes;
350  const SourceManager &SourceMgr;
351  tooling::Replacements Replaces;
352  const FormatStyle &Style;
353  bool UseCRLF;
354 };
355 
356 } // namespace format
357 } // namespace clang
358 
359 #endif
clang::operator!=
bool operator!=(CanQual< T > x, CanQual< U > y)
Definition: CanonicalType.h:207
clang::format::WhitespaceManager::Change::Spaces
int Spaces
Definition: WhitespaceManager.h:142
clang::format::WhitespaceManager::Change::ConditionalsLevel
int ConditionalsLevel
Definition: WhitespaceManager.h:169
max
__DEVICE__ int max(int __a, int __b)
Definition: __clang_cuda_math.h:196
clang::SourceRange
A trivial tuple used to represent a source range.
Definition: SourceLocation.h:210
string
string(SUBSTRING ${CMAKE_CURRENT_BINARY_DIR} 0 ${PATH_LIB_START} PATH_HEAD) string(SUBSTRING $
Definition: CMakeLists.txt:22
clang::format::WhitespaceManager::Change::StartOfTokenColumn
unsigned StartOfTokenColumn
Definition: WhitespaceManager.h:130
clang::format::WhitespaceManager::generateReplacements
const tooling::Replacements & generateReplacements()
Returns all the Replacements created during formatting.
Definition: WhitespaceManager.cpp:98
clang::format::WhitespaceManager::inputUsesCRLF
static bool inputUsesCRLF(StringRef Text, bool DefaultToCRLF)
Infers whether the input is using CRLF.
Definition: WhitespaceManager.cpp:77
clang::format::WhitespaceManager::Change::IsBeforeInFile::IsBeforeInFile
IsBeforeInFile(const SourceManager &SourceMgr)
Definition: WhitespaceManager.h:98
clang::tooling::Replacements
Maintains a set of replacements that are conflict-free.
Definition: Replacement.h:209
clang::format::WhitespaceManager::Change::PreviousLinePostfix
std::string PreviousLinePostfix
Definition: WhitespaceManager.h:132
clang::format::WhitespaceManager::addUntouchableToken
void addUntouchableToken(const FormatToken &Tok, bool InPPDirective)
Adds information about an unchangeable token's whitespace.
Definition: WhitespaceManager.cpp:61
clang::format::WhitespaceManager::Change::CreateReplacement
bool CreateReplacement
Definition: WhitespaceManager.h:126
clang::format::FormatToken::IndentLevel
unsigned IndentLevel
The indent level of this token. Copied from the surrounding line.
Definition: FormatToken.h:426
clang::format::FormatStyle
The FormatStyle is used to configure the formatting to follow specific guidelines.
Definition: Format.h:54
clang::format::FormatToken
A wrapper around a Token storing information about the whitespace characters preceding it.
Definition: FormatToken.h:227
SourceManager.h
clang::format::WhitespaceManager::Change::Tok
const FormatToken * Tok
Definition: WhitespaceManager.h:124
Format.h
End
SourceLocation End
Definition: USRLocFinder.cpp:167
clang::format::WhitespaceManager::addReplacement
llvm::Error addReplacement(const tooling::Replacement &Replacement)
Definition: WhitespaceManager.cpp:73
clang::SourceManager
This class handles loading and caching of source files into memory.
Definition: SourceManager.h:627
clang::format::WhitespaceManager::Change::IndentationOffset
int IndentationOffset
Definition: WhitespaceManager.h:165
clang::format::WhitespaceManager::Change
Represents a change before a token, a break inside a token, or the layout of an unchanged token (or w...
Definition: WhitespaceManager.h:94
Offset
unsigned Offset
Definition: Format.cpp:2574
TokenAnnotator.h
U
clang::format::FormatToken::NestingLevel
unsigned NestingLevel
The nesting level of this token, i.e.
Definition: FormatToken.h:423
clang::format::WhitespaceManager::Change::OriginalWhitespaceRange
SourceRange OriginalWhitespaceRange
Definition: WhitespaceManager.h:129
clang::format::WhitespaceManager::Change::IsTrailingComment
bool IsTrailingComment
Definition: WhitespaceManager.h:151
clang::format::WhitespaceManager::Change::indentAndNestingLevel
std::tuple< unsigned, unsigned, unsigned > indentAndNestingLevel() const
Definition: WhitespaceManager.h:174
clang::format::WhitespaceManager::Change::IsInsideToken
bool IsInsideToken
Definition: WhitespaceManager.h:146
clang::format::WhitespaceManager
Manages the whitespaces around tokens and their replacements.
Definition: WhitespaceManager.h:40
clang::format::WhitespaceManager::Change::IsAligned
bool IsAligned
Definition: WhitespaceManager.h:134
clang::format::WhitespaceManager::Change::Change
Change(const FormatToken &Tok, bool CreateReplacement, SourceRange OriginalWhitespaceRange, int Spaces, unsigned StartOfTokenColumn, unsigned NewlinesBefore, StringRef PreviousLinePostfix, StringRef CurrentLinePrefix, bool IsAligned, bool ContinuesPPDirective, bool IsInsideToken)
Creates a Change.
Definition: WhitespaceManager.cpp:29
clang::format::WhitespaceManager::Change::NewlinesBefore
unsigned NewlinesBefore
Definition: WhitespaceManager.h:131
clang::format::WhitespaceManager::Change::TokenLength
unsigned TokenLength
Definition: WhitespaceManager.h:152
clang::format::WhitespaceManager::Change::ContinuesPPDirective
bool ContinuesPPDirective
Definition: WhitespaceManager.h:135
clang::format::WhitespaceManager::Change::CurrentLinePrefix
std::string CurrentLinePrefix
Definition: WhitespaceManager.h:133
clang::format::WhitespaceManager::WhitespaceManager
WhitespaceManager(const SourceManager &SourceMgr, const FormatStyle &Style, bool UseCRLF)
Definition: WhitespaceManager.h:42
clang::tooling::Replacement
A text replacement.
Definition: Replacement.h:83
clang::format::WhitespaceManager::Change::PreviousEndOfTokenColumn
unsigned PreviousEndOfTokenColumn
Definition: WhitespaceManager.h:153
clang::format::WhitespaceManager::useCRLF
bool useCRLF() const
Definition: WhitespaceManager.h:46
clang::format::WhitespaceManager::Change::StartOfBlockComment
const Change * StartOfBlockComment
Definition: WhitespaceManager.h:164
clang::format::WhitespaceManager::Change::IsBeforeInFile::operator()
bool operator()(const Change &C1, const Change &C2) const
Definition: WhitespaceManager.cpp:22
clang
Definition: CalledOnceCheck.h:17
Text
StringRef Text
Definition: Format.cpp:2573
distance
float __ovld __cnfn distance(float, float)
Returns the distance between p0 and p1.
clang::format::WhitespaceManager::Change::EscapedNewlineColumn
unsigned EscapedNewlineColumn
Definition: WhitespaceManager.h:154
clang::format::WhitespaceManager::Change::IsBeforeInFile
Functor to sort changes in original source order.
Definition: WhitespaceManager.h:96
clang::format::WhitespaceManager::replaceWhitespaceInToken
void replaceWhitespaceInToken(const FormatToken &Tok, unsigned Offset, unsigned ReplaceChars, StringRef PreviousPostfix, StringRef CurrentPrefix, bool InPPDirective, unsigned Newlines, int Spaces)
Inserts or replaces whitespace in the middle of a token.
Definition: WhitespaceManager.cpp:83
clang::operator==
bool operator==(const CallGraphNode::CallRecord &LHS, const CallGraphNode::CallRecord &RHS)
Definition: CallGraph.h:207
clang::format::WhitespaceManager::replaceWhitespace
void replaceWhitespace(FormatToken &Tok, unsigned Newlines, unsigned Spaces, unsigned StartOfTokenColumn, bool isAligned=false, bool InPPDirective=false)
Replaces the whitespace in front of Tok.
Definition: WhitespaceManager.cpp:48