1 //===--- WhitespaceManager.cpp - Format C++ code --------------------------===//
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
7 //===----------------------------------------------------------------------===//
10 /// This file implements WhitespaceManager class.
12 //===----------------------------------------------------------------------===//
14 #include "WhitespaceManager.h"
15 #include "llvm/ADT/STLExtras.h"
20 bool WhitespaceManager::Change::IsBeforeInFile::
21 operator()(const Change &C1, const Change &C2) const {
22 return SourceMgr.isBeforeInTranslationUnit(
23 C1.OriginalWhitespaceRange.getBegin(),
24 C2.OriginalWhitespaceRange.getBegin());
27 WhitespaceManager::Change::Change(const FormatToken &Tok,
28 bool CreateReplacement,
29 SourceRange OriginalWhitespaceRange,
30 int Spaces, unsigned StartOfTokenColumn,
31 unsigned NewlinesBefore,
32 StringRef PreviousLinePostfix,
33 StringRef CurrentLinePrefix,
34 bool ContinuesPPDirective, bool IsInsideToken)
35 : Tok(&Tok), CreateReplacement(CreateReplacement),
36 OriginalWhitespaceRange(OriginalWhitespaceRange),
37 StartOfTokenColumn(StartOfTokenColumn), NewlinesBefore(NewlinesBefore),
38 PreviousLinePostfix(PreviousLinePostfix),
39 CurrentLinePrefix(CurrentLinePrefix),
40 ContinuesPPDirective(ContinuesPPDirective), Spaces(Spaces),
41 IsInsideToken(IsInsideToken), IsTrailingComment(false), TokenLength(0),
42 PreviousEndOfTokenColumn(0), EscapedNewlineColumn(0),
43 StartOfBlockComment(nullptr), IndentationOffset(0) {}
45 void WhitespaceManager::replaceWhitespace(FormatToken &Tok, unsigned Newlines,
47 unsigned StartOfTokenColumn,
51 Tok.Decision = (Newlines > 0) ? FD_Break : FD_Continue;
52 Changes.push_back(Change(Tok, /*CreateReplacement=*/true, Tok.WhitespaceRange,
53 Spaces, StartOfTokenColumn, Newlines, "", "",
54 InPPDirective && !Tok.IsFirst,
55 /*IsInsideToken=*/false));
58 void WhitespaceManager::addUntouchableToken(const FormatToken &Tok,
62 Changes.push_back(Change(Tok, /*CreateReplacement=*/false,
63 Tok.WhitespaceRange, /*Spaces=*/0,
64 Tok.OriginalColumn, Tok.NewlinesBefore, "", "",
65 InPPDirective && !Tok.IsFirst,
66 /*IsInsideToken=*/false));
70 WhitespaceManager::addReplacement(const tooling::Replacement &Replacement) {
71 return Replaces.add(Replacement);
74 void WhitespaceManager::replaceWhitespaceInToken(
75 const FormatToken &Tok, unsigned Offset, unsigned ReplaceChars,
76 StringRef PreviousPostfix, StringRef CurrentPrefix, bool InPPDirective,
77 unsigned Newlines, int Spaces) {
80 SourceLocation Start = Tok.getStartOfNonWhitespace().getLocWithOffset(Offset);
82 Change(Tok, /*CreateReplacement=*/true,
83 SourceRange(Start, Start.getLocWithOffset(ReplaceChars)), Spaces,
84 std::max(0, Spaces), Newlines, PreviousPostfix, CurrentPrefix,
85 InPPDirective && !Tok.IsFirst, /*IsInsideToken=*/true));
88 const tooling::Replacements &WhitespaceManager::generateReplacements() {
92 llvm::sort(Changes, Change::IsBeforeInFile(SourceMgr));
93 calculateLineBreakInformation();
94 alignConsecutiveMacros();
95 alignConsecutiveDeclarations();
96 alignConsecutiveAssignments();
97 alignTrailingComments();
98 alignEscapedNewlines();
104 void WhitespaceManager::calculateLineBreakInformation() {
105 Changes[0].PreviousEndOfTokenColumn = 0;
106 Change *LastOutsideTokenChange = &Changes[0];
107 for (unsigned i = 1, e = Changes.size(); i != e; ++i) {
108 SourceLocation OriginalWhitespaceStart =
109 Changes[i].OriginalWhitespaceRange.getBegin();
110 SourceLocation PreviousOriginalWhitespaceEnd =
111 Changes[i - 1].OriginalWhitespaceRange.getEnd();
112 unsigned OriginalWhitespaceStartOffset =
113 SourceMgr.getFileOffset(OriginalWhitespaceStart);
114 unsigned PreviousOriginalWhitespaceEndOffset =
115 SourceMgr.getFileOffset(PreviousOriginalWhitespaceEnd);
116 assert(PreviousOriginalWhitespaceEndOffset <=
117 OriginalWhitespaceStartOffset);
118 const char *const PreviousOriginalWhitespaceEndData =
119 SourceMgr.getCharacterData(PreviousOriginalWhitespaceEnd);
120 StringRef Text(PreviousOriginalWhitespaceEndData,
121 SourceMgr.getCharacterData(OriginalWhitespaceStart) -
122 PreviousOriginalWhitespaceEndData);
123 // Usually consecutive changes would occur in consecutive tokens. This is
124 // not the case however when analyzing some preprocessor runs of the
125 // annotated lines. For example, in this code:
133 // one of the runs will produce the sequence of lines marked with line 1, 2
134 // and 3. So the two consecutive whitespace changes just before '// line 2'
135 // and before '#endif // line 3' span multiple lines and tokens:
137 // #else B{change X}[// line 2
139 // ]{change Y}#endif // line 3
141 // For this reason, if the text between consecutive changes spans multiple
142 // newlines, the token length must be adjusted to the end of the original
143 // line of the token.
144 auto NewlinePos = Text.find_first_of('\n');
145 if (NewlinePos == StringRef::npos) {
146 Changes[i - 1].TokenLength = OriginalWhitespaceStartOffset -
147 PreviousOriginalWhitespaceEndOffset +
148 Changes[i].PreviousLinePostfix.size() +
149 Changes[i - 1].CurrentLinePrefix.size();
151 Changes[i - 1].TokenLength =
152 NewlinePos + Changes[i - 1].CurrentLinePrefix.size();
155 // If there are multiple changes in this token, sum up all the changes until
156 // the end of the line.
157 if (Changes[i - 1].IsInsideToken && Changes[i - 1].NewlinesBefore == 0)
158 LastOutsideTokenChange->TokenLength +=
159 Changes[i - 1].TokenLength + Changes[i - 1].Spaces;
161 LastOutsideTokenChange = &Changes[i - 1];
163 Changes[i].PreviousEndOfTokenColumn =
164 Changes[i - 1].StartOfTokenColumn + Changes[i - 1].TokenLength;
166 Changes[i - 1].IsTrailingComment =
167 (Changes[i].NewlinesBefore > 0 || Changes[i].Tok->is(tok::eof) ||
168 (Changes[i].IsInsideToken && Changes[i].Tok->is(tok::comment))) &&
169 Changes[i - 1].Tok->is(tok::comment) &&
170 // FIXME: This is a dirty hack. The problem is that
171 // BreakableLineCommentSection does comment reflow changes and here is
172 // the aligning of trailing comments. Consider the case where we reflow
173 // the second line up in this example:
178 // That amounts to 2 changes by BreakableLineCommentSection:
179 // - the first, delimited by (), for the whitespace between the tokens,
180 // - and second, delimited by [], for the whitespace at the beginning
181 // of the second token:
186 // So in the end we have two changes like this:
188 // // line1()[ ]line 2
190 // Note that the OriginalWhitespaceStart of the second change is the
191 // same as the PreviousOriginalWhitespaceEnd of the first change.
192 // In this case, the below check ensures that the second change doesn't
193 // get treated as a trailing comment change here, since this might
194 // trigger additional whitespace to be wrongly inserted before "line 2"
195 // by the comment aligner here.
197 // For a proper solution we need a mechanism to say to WhitespaceManager
198 // that a particular change breaks the current sequence of trailing
200 OriginalWhitespaceStart != PreviousOriginalWhitespaceEnd;
202 // FIXME: The last token is currently not always an eof token; in those
203 // cases, setting TokenLength of the last token to 0 is wrong.
204 Changes.back().TokenLength = 0;
205 Changes.back().IsTrailingComment = Changes.back().Tok->is(tok::comment);
207 const WhitespaceManager::Change *LastBlockComment = nullptr;
208 for (auto &Change : Changes) {
209 // Reset the IsTrailingComment flag for changes inside of trailing comments
210 // so they don't get realigned later. Comment line breaks however still need
212 if (Change.IsInsideToken && Change.NewlinesBefore == 0)
213 Change.IsTrailingComment = false;
214 Change.StartOfBlockComment = nullptr;
215 Change.IndentationOffset = 0;
216 if (Change.Tok->is(tok::comment)) {
217 if (Change.Tok->is(TT_LineComment) || !Change.IsInsideToken)
218 LastBlockComment = &Change;
220 if ((Change.StartOfBlockComment = LastBlockComment))
221 Change.IndentationOffset =
222 Change.StartOfTokenColumn -
223 Change.StartOfBlockComment->StartOfTokenColumn;
226 LastBlockComment = nullptr;
231 // Align a single sequence of tokens, see AlignTokens below.
232 template <typename F>
234 AlignTokenSequence(unsigned Start, unsigned End, unsigned Column, F &&Matches,
235 SmallVector<WhitespaceManager::Change, 16> &Changes) {
236 bool FoundMatchOnLine = false;
239 // ScopeStack keeps track of the current scope depth. It contains indices of
240 // the first token on each scope.
241 // We only run the "Matches" function on tokens from the outer-most scope.
242 // However, we do need to pay special attention to one class of tokens
243 // that are not in the outer-most scope, and that is function parameters
244 // which are split across multiple lines, as illustrated by this example:
248 // In the above example, we need to take special care to ensure that
249 // 'double z' is indented along with it's owning function 'b'.
250 SmallVector<unsigned, 16> ScopeStack;
252 for (unsigned i = Start; i != End; ++i) {
253 if (ScopeStack.size() != 0 &&
254 Changes[i].indentAndNestingLevel() <
255 Changes[ScopeStack.back()].indentAndNestingLevel())
256 ScopeStack.pop_back();
258 // Compare current token to previous non-comment token to ensure whether
259 // it is in a deeper scope or not.
260 unsigned PreviousNonComment = i - 1;
261 while (PreviousNonComment > Start &&
262 Changes[PreviousNonComment].Tok->is(tok::comment))
263 PreviousNonComment--;
264 if (i != Start && Changes[i].indentAndNestingLevel() >
265 Changes[PreviousNonComment].indentAndNestingLevel())
266 ScopeStack.push_back(i);
268 bool InsideNestedScope = ScopeStack.size() != 0;
270 if (Changes[i].NewlinesBefore > 0 && !InsideNestedScope) {
272 FoundMatchOnLine = false;
275 // If this is the first matching token to be aligned, remember by how many
276 // spaces it has to be shifted, so the rest of the changes on the line are
277 // shifted by the same amount
278 if (!FoundMatchOnLine && !InsideNestedScope && Matches(Changes[i])) {
279 FoundMatchOnLine = true;
280 Shift = Column - Changes[i].StartOfTokenColumn;
281 Changes[i].Spaces += Shift;
284 // This is for function parameters that are split across multiple lines,
285 // as mentioned in the ScopeStack comment.
286 if (InsideNestedScope && Changes[i].NewlinesBefore > 0) {
287 unsigned ScopeStart = ScopeStack.back();
288 if (Changes[ScopeStart - 1].Tok->is(TT_FunctionDeclarationName) ||
289 (ScopeStart > Start + 1 &&
290 Changes[ScopeStart - 2].Tok->is(TT_FunctionDeclarationName)))
291 Changes[i].Spaces += Shift;
295 Changes[i].StartOfTokenColumn += Shift;
296 if (i + 1 != Changes.size())
297 Changes[i + 1].PreviousEndOfTokenColumn += Shift;
301 // Walk through a subset of the changes, starting at StartAt, and find
302 // sequences of matching tokens to align. To do so, keep track of the lines and
303 // whether or not a matching token was found on a line. If a matching token is
304 // found, extend the current sequence. If the current line cannot be part of a
305 // sequence, e.g. because there is an empty line before it or it contains only
306 // non-matching tokens, finalize the previous sequence.
307 // The value returned is the token on which we stopped, either because we
308 // exhausted all items inside Changes, or because we hit a scope level higher
309 // than our initial scope.
310 // This function is recursive. Each invocation processes only the scope level
311 // equal to the initial level, which is the level of Changes[StartAt].
312 // If we encounter a scope level greater than the initial level, then we call
313 // ourselves recursively, thereby avoiding the pollution of the current state
314 // with the alignment requirements of the nested sub-level. This recursive
315 // behavior is necessary for aligning function prototypes that have one or more
317 // If this function encounters a scope level less than the initial level,
318 // it returns the current position.
319 // There is a non-obvious subtlety in the recursive behavior: Even though we
320 // defer processing of nested levels to recursive invocations of this
321 // function, when it comes time to align a sequence of tokens, we run the
322 // alignment on the entire sequence, including the nested levels.
323 // When doing so, most of the nested tokens are skipped, because their
324 // alignment was already handled by the recursive invocations of this function.
325 // However, the special exception is that we do NOT skip function parameters
326 // that are split across multiple lines. See the test case in FormatTest.cpp
327 // that mentions "split function parameter alignment" for an example of this.
328 template <typename F>
329 static unsigned AlignTokens(const FormatStyle &Style, F &&Matches,
330 SmallVector<WhitespaceManager::Change, 16> &Changes,
332 unsigned MinColumn = 0;
333 unsigned MaxColumn = UINT_MAX;
335 // Line number of the start and the end of the current token sequence.
336 unsigned StartOfSequence = 0;
337 unsigned EndOfSequence = 0;
339 // Measure the scope level (i.e. depth of (), [], {}) of the first token, and
340 // abort when we hit any token in a higher scope than the starting one.
341 auto IndentAndNestingLevel = StartAt < Changes.size()
342 ? Changes[StartAt].indentAndNestingLevel()
343 : std::pair<unsigned, unsigned>(0, 0);
345 // Keep track of the number of commas before the matching tokens, we will only
346 // align a sequence of matching tokens if they are preceded by the same number
348 unsigned CommasBeforeLastMatch = 0;
349 unsigned CommasBeforeMatch = 0;
351 // Whether a matching token has been found on the current line.
352 bool FoundMatchOnLine = false;
354 // Aligns a sequence of matching tokens, on the MinColumn column.
356 // Sequences start from the first matching token to align, and end at the
357 // first token of the first line that doesn't need to be aligned.
359 // We need to adjust the StartOfTokenColumn of each Change that is on a line
360 // containing any matching token to be aligned and located after such token.
361 auto AlignCurrentSequence = [&] {
362 if (StartOfSequence > 0 && StartOfSequence < EndOfSequence)
363 AlignTokenSequence(StartOfSequence, EndOfSequence, MinColumn, Matches,
366 MaxColumn = UINT_MAX;
371 unsigned i = StartAt;
372 for (unsigned e = Changes.size(); i != e; ++i) {
373 if (Changes[i].indentAndNestingLevel() < IndentAndNestingLevel)
376 if (Changes[i].NewlinesBefore != 0) {
377 CommasBeforeMatch = 0;
379 // If there is a blank line, or if the last line didn't contain any
380 // matching token, the sequence ends here.
381 if (Changes[i].NewlinesBefore > 1 || !FoundMatchOnLine)
382 AlignCurrentSequence();
384 FoundMatchOnLine = false;
387 if (Changes[i].Tok->is(tok::comma)) {
389 } else if (Changes[i].indentAndNestingLevel() > IndentAndNestingLevel) {
390 // Call AlignTokens recursively, skipping over this scope block.
391 unsigned StoppedAt = AlignTokens(Style, Matches, Changes, i);
396 if (!Matches(Changes[i]))
399 // If there is more than one matching token per line, or if the number of
400 // preceding commas, do not match anymore, end the sequence.
401 if (FoundMatchOnLine || CommasBeforeMatch != CommasBeforeLastMatch)
402 AlignCurrentSequence();
404 CommasBeforeLastMatch = CommasBeforeMatch;
405 FoundMatchOnLine = true;
407 if (StartOfSequence == 0)
410 unsigned ChangeMinColumn = Changes[i].StartOfTokenColumn;
411 int LineLengthAfter = -Changes[i].Spaces;
412 for (unsigned j = i; j != e && Changes[j].NewlinesBefore == 0; ++j)
413 LineLengthAfter += Changes[j].Spaces + Changes[j].TokenLength;
414 unsigned ChangeMaxColumn = Style.ColumnLimit - LineLengthAfter;
416 // If we are restricted by the maximum column width, end the sequence.
417 if (ChangeMinColumn > MaxColumn || ChangeMaxColumn < MinColumn ||
418 CommasBeforeLastMatch != CommasBeforeMatch) {
419 AlignCurrentSequence();
423 MinColumn = std::max(MinColumn, ChangeMinColumn);
424 MaxColumn = std::min(MaxColumn, ChangeMaxColumn);
428 AlignCurrentSequence();
432 // Aligns a sequence of matching tokens, on the MinColumn column.
434 // Sequences start from the first matching token to align, and end at the
435 // first token of the first line that doesn't need to be aligned.
437 // We need to adjust the StartOfTokenColumn of each Change that is on a line
438 // containing any matching token to be aligned and located after such token.
439 static void AlignMacroSequence(
440 unsigned &StartOfSequence, unsigned &EndOfSequence, unsigned &MinColumn,
441 unsigned &MaxColumn, bool &FoundMatchOnLine,
442 std::function<bool(const WhitespaceManager::Change &C)> AlignMacrosMatches,
443 SmallVector<WhitespaceManager::Change, 16> &Changes) {
444 if (StartOfSequence > 0 && StartOfSequence < EndOfSequence) {
446 FoundMatchOnLine = false;
449 for (unsigned I = StartOfSequence; I != EndOfSequence; ++I) {
450 if (Changes[I].NewlinesBefore > 0) {
452 FoundMatchOnLine = false;
455 // If this is the first matching token to be aligned, remember by how many
456 // spaces it has to be shifted, so the rest of the changes on the line are
457 // shifted by the same amount
458 if (!FoundMatchOnLine && AlignMacrosMatches(Changes[I])) {
459 FoundMatchOnLine = true;
460 Shift = MinColumn - Changes[I].StartOfTokenColumn;
461 Changes[I].Spaces += Shift;
465 Changes[I].StartOfTokenColumn += Shift;
466 if (I + 1 != Changes.size())
467 Changes[I + 1].PreviousEndOfTokenColumn += Shift;
472 MaxColumn = UINT_MAX;
477 void WhitespaceManager::alignConsecutiveMacros() {
478 if (!Style.AlignConsecutiveMacros)
481 auto AlignMacrosMatches = [](const Change &C) {
482 const FormatToken *Current = C.Tok;
483 unsigned SpacesRequiredBefore = 1;
485 if (Current->SpacesRequiredBefore == 0 || !Current->Previous)
488 Current = Current->Previous;
490 // If token is a ")", skip over the parameter list, to the
491 // token that precedes the "("
492 if (Current->is(tok::r_paren) && Current->MatchingParen) {
493 Current = Current->MatchingParen->Previous;
494 SpacesRequiredBefore = 0;
497 if (!Current || !Current->is(tok::identifier))
500 if (!Current->Previous || !Current->Previous->is(tok::pp_define))
503 // For a macro function, 0 spaces are required between the
504 // identifier and the lparen that opens the parameter list.
505 // For a simple macro, 1 space is required between the
506 // identifier and the first token of the defined value.
507 return Current->Next->SpacesRequiredBefore == SpacesRequiredBefore;
510 unsigned MinColumn = 0;
511 unsigned MaxColumn = UINT_MAX;
513 // Start and end of the token sequence we're processing.
514 unsigned StartOfSequence = 0;
515 unsigned EndOfSequence = 0;
517 // Whether a matching token has been found on the current line.
518 bool FoundMatchOnLine = false;
521 for (unsigned E = Changes.size(); I != E; ++I) {
522 if (Changes[I].NewlinesBefore != 0) {
524 // If there is a blank line, or if the last line didn't contain any
525 // matching token, the sequence ends here.
526 if (Changes[I].NewlinesBefore > 1 || !FoundMatchOnLine)
527 AlignMacroSequence(StartOfSequence, EndOfSequence, MinColumn, MaxColumn,
528 FoundMatchOnLine, AlignMacrosMatches, Changes);
530 FoundMatchOnLine = false;
533 if (!AlignMacrosMatches(Changes[I]))
536 FoundMatchOnLine = true;
538 if (StartOfSequence == 0)
541 unsigned ChangeMinColumn = Changes[I].StartOfTokenColumn;
542 int LineLengthAfter = -Changes[I].Spaces;
543 for (unsigned j = I; j != E && Changes[j].NewlinesBefore == 0; ++j)
544 LineLengthAfter += Changes[j].Spaces + Changes[j].TokenLength;
545 unsigned ChangeMaxColumn = Style.ColumnLimit - LineLengthAfter;
547 MinColumn = std::max(MinColumn, ChangeMinColumn);
548 MaxColumn = std::min(MaxColumn, ChangeMaxColumn);
552 AlignMacroSequence(StartOfSequence, EndOfSequence, MinColumn, MaxColumn,
553 FoundMatchOnLine, AlignMacrosMatches, Changes);
556 void WhitespaceManager::alignConsecutiveAssignments() {
557 if (!Style.AlignConsecutiveAssignments)
562 [&](const Change &C) {
563 // Do not align on equal signs that are first on a line.
564 if (C.NewlinesBefore > 0)
567 // Do not align on equal signs that are last on a line.
568 if (&C != &Changes.back() && (&C + 1)->NewlinesBefore > 0)
571 return C.Tok->is(tok::equal);
573 Changes, /*StartAt=*/0);
576 void WhitespaceManager::alignConsecutiveDeclarations() {
577 if (!Style.AlignConsecutiveDeclarations)
580 // FIXME: Currently we don't handle properly the PointerAlignment: Right
581 // The * and & are not aligned and are left dangling. Something has to be done
582 // about it, but it raises the question of alignment of code like:
583 // const char* const* v1;
585 // SomeVeryLongType const& v3;
588 [](Change const &C) {
589 // tok::kw_operator is necessary for aligning operator overload
591 if (C.Tok->isOneOf(TT_FunctionDeclarationName, tok::kw_operator))
593 if (C.Tok->isNot(TT_StartOfName))
595 // Check if there is a subsequent name that starts the same declaration.
596 for (FormatToken *Next = C.Tok->Next; Next; Next = Next->Next) {
597 if (Next->is(tok::comment))
599 if (!Next->Tok.getIdentifierInfo())
601 if (Next->isOneOf(TT_StartOfName, TT_FunctionDeclarationName,
607 Changes, /*StartAt=*/0);
610 void WhitespaceManager::alignTrailingComments() {
611 unsigned MinColumn = 0;
612 unsigned MaxColumn = UINT_MAX;
613 unsigned StartOfSequence = 0;
614 bool BreakBeforeNext = false;
615 unsigned Newlines = 0;
616 for (unsigned i = 0, e = Changes.size(); i != e; ++i) {
617 if (Changes[i].StartOfBlockComment)
619 Newlines += Changes[i].NewlinesBefore;
620 if (!Changes[i].IsTrailingComment)
623 unsigned ChangeMinColumn = Changes[i].StartOfTokenColumn;
624 unsigned ChangeMaxColumn;
626 if (Style.ColumnLimit == 0)
627 ChangeMaxColumn = UINT_MAX;
628 else if (Style.ColumnLimit >= Changes[i].TokenLength)
629 ChangeMaxColumn = Style.ColumnLimit - Changes[i].TokenLength;
631 ChangeMaxColumn = ChangeMinColumn;
633 // If we don't create a replacement for this change, we have to consider
634 // it to be immovable.
635 if (!Changes[i].CreateReplacement)
636 ChangeMaxColumn = ChangeMinColumn;
638 if (i + 1 != e && Changes[i + 1].ContinuesPPDirective)
639 ChangeMaxColumn -= 2;
640 // If this comment follows an } in column 0, it probably documents the
641 // closing of a namespace and we don't want to align it.
642 bool FollowsRBraceInColumn0 = i > 0 && Changes[i].NewlinesBefore == 0 &&
643 Changes[i - 1].Tok->is(tok::r_brace) &&
644 Changes[i - 1].StartOfTokenColumn == 0;
645 bool WasAlignedWithStartOfNextLine = false;
646 if (Changes[i].NewlinesBefore == 1) { // A comment on its own line.
647 unsigned CommentColumn = SourceMgr.getSpellingColumnNumber(
648 Changes[i].OriginalWhitespaceRange.getEnd());
649 for (unsigned j = i + 1; j != e; ++j) {
650 if (Changes[j].Tok->is(tok::comment))
653 unsigned NextColumn = SourceMgr.getSpellingColumnNumber(
654 Changes[j].OriginalWhitespaceRange.getEnd());
655 // The start of the next token was previously aligned with the
656 // start of this comment.
657 WasAlignedWithStartOfNextLine =
658 CommentColumn == NextColumn ||
659 CommentColumn == NextColumn + Style.IndentWidth;
663 if (!Style.AlignTrailingComments || FollowsRBraceInColumn0) {
664 alignTrailingComments(StartOfSequence, i, MinColumn);
665 MinColumn = ChangeMinColumn;
666 MaxColumn = ChangeMinColumn;
668 } else if (BreakBeforeNext || Newlines > 1 ||
669 (ChangeMinColumn > MaxColumn || ChangeMaxColumn < MinColumn) ||
670 // Break the comment sequence if the previous line did not end
671 // in a trailing comment.
672 (Changes[i].NewlinesBefore == 1 && i > 0 &&
673 !Changes[i - 1].IsTrailingComment) ||
674 WasAlignedWithStartOfNextLine) {
675 alignTrailingComments(StartOfSequence, i, MinColumn);
676 MinColumn = ChangeMinColumn;
677 MaxColumn = ChangeMaxColumn;
680 MinColumn = std::max(MinColumn, ChangeMinColumn);
681 MaxColumn = std::min(MaxColumn, ChangeMaxColumn);
683 BreakBeforeNext = (i == 0) || (Changes[i].NewlinesBefore > 1) ||
684 // Never start a sequence with a comment at the beginning
686 (Changes[i].NewlinesBefore == 1 && StartOfSequence == i);
689 alignTrailingComments(StartOfSequence, Changes.size(), MinColumn);
692 void WhitespaceManager::alignTrailingComments(unsigned Start, unsigned End,
694 for (unsigned i = Start; i != End; ++i) {
696 if (Changes[i].IsTrailingComment) {
697 Shift = Column - Changes[i].StartOfTokenColumn;
699 if (Changes[i].StartOfBlockComment) {
700 Shift = Changes[i].IndentationOffset +
701 Changes[i].StartOfBlockComment->StartOfTokenColumn -
702 Changes[i].StartOfTokenColumn;
705 Changes[i].Spaces += Shift;
706 if (i + 1 != Changes.size())
707 Changes[i + 1].PreviousEndOfTokenColumn += Shift;
708 Changes[i].StartOfTokenColumn += Shift;
712 void WhitespaceManager::alignEscapedNewlines() {
713 if (Style.AlignEscapedNewlines == FormatStyle::ENAS_DontAlign)
716 bool AlignLeft = Style.AlignEscapedNewlines == FormatStyle::ENAS_Left;
717 unsigned MaxEndOfLine = AlignLeft ? 0 : Style.ColumnLimit;
718 unsigned StartOfMacro = 0;
719 for (unsigned i = 1, e = Changes.size(); i < e; ++i) {
720 Change &C = Changes[i];
721 if (C.NewlinesBefore > 0) {
722 if (C.ContinuesPPDirective) {
723 MaxEndOfLine = std::max(C.PreviousEndOfTokenColumn + 2, MaxEndOfLine);
725 alignEscapedNewlines(StartOfMacro + 1, i, MaxEndOfLine);
726 MaxEndOfLine = AlignLeft ? 0 : Style.ColumnLimit;
731 alignEscapedNewlines(StartOfMacro + 1, Changes.size(), MaxEndOfLine);
734 void WhitespaceManager::alignEscapedNewlines(unsigned Start, unsigned End,
736 for (unsigned i = Start; i < End; ++i) {
737 Change &C = Changes[i];
738 if (C.NewlinesBefore > 0) {
739 assert(C.ContinuesPPDirective);
740 if (C.PreviousEndOfTokenColumn + 1 > Column)
741 C.EscapedNewlineColumn = 0;
743 C.EscapedNewlineColumn = Column;
748 void WhitespaceManager::generateChanges() {
749 for (unsigned i = 0, e = Changes.size(); i != e; ++i) {
750 const Change &C = Changes[i];
752 assert(Changes[i - 1].OriginalWhitespaceRange.getBegin() !=
753 C.OriginalWhitespaceRange.getBegin() &&
754 "Generating two replacements for the same location");
756 if (C.CreateReplacement) {
757 std::string ReplacementText = C.PreviousLinePostfix;
758 if (C.ContinuesPPDirective)
759 appendEscapedNewlineText(ReplacementText, C.NewlinesBefore,
760 C.PreviousEndOfTokenColumn,
761 C.EscapedNewlineColumn);
763 appendNewlineText(ReplacementText, C.NewlinesBefore);
764 appendIndentText(ReplacementText, C.Tok->IndentLevel,
765 std::max(0, C.Spaces),
766 C.StartOfTokenColumn - std::max(0, C.Spaces));
767 ReplacementText.append(C.CurrentLinePrefix);
768 storeReplacement(C.OriginalWhitespaceRange, ReplacementText);
773 void WhitespaceManager::storeReplacement(SourceRange Range, StringRef Text) {
774 unsigned WhitespaceLength = SourceMgr.getFileOffset(Range.getEnd()) -
775 SourceMgr.getFileOffset(Range.getBegin());
776 // Don't create a replacement, if it does not change anything.
777 if (StringRef(SourceMgr.getCharacterData(Range.getBegin()),
778 WhitespaceLength) == Text)
780 auto Err = Replaces.add(tooling::Replacement(
781 SourceMgr, CharSourceRange::getCharRange(Range), Text));
782 // FIXME: better error handling. For now, just print an error message in the
785 llvm::errs() << llvm::toString(std::move(Err)) << "\n";
790 void WhitespaceManager::appendNewlineText(std::string &Text,
792 for (unsigned i = 0; i < Newlines; ++i)
793 Text.append(UseCRLF ? "\r\n" : "\n");
796 void WhitespaceManager::appendEscapedNewlineText(
797 std::string &Text, unsigned Newlines, unsigned PreviousEndOfTokenColumn,
798 unsigned EscapedNewlineColumn) {
801 std::max<int>(1, EscapedNewlineColumn - PreviousEndOfTokenColumn - 1);
802 for (unsigned i = 0; i < Newlines; ++i) {
803 Text.append(Spaces, ' ');
804 Text.append(UseCRLF ? "\\\r\n" : "\\\n");
805 Spaces = std::max<int>(0, EscapedNewlineColumn - 1);
810 void WhitespaceManager::appendIndentText(std::string &Text,
811 unsigned IndentLevel, unsigned Spaces,
812 unsigned WhitespaceStartColumn) {
813 switch (Style.UseTab) {
814 case FormatStyle::UT_Never:
815 Text.append(Spaces, ' ');
817 case FormatStyle::UT_Always: {
818 unsigned FirstTabWidth =
819 Style.TabWidth - WhitespaceStartColumn % Style.TabWidth;
820 // Insert only spaces when we want to end up before the next tab.
821 if (Spaces < FirstTabWidth || Spaces == 1) {
822 Text.append(Spaces, ' ');
825 // Align to the next tab.
826 Spaces -= FirstTabWidth;
829 Text.append(Spaces / Style.TabWidth, '\t');
830 Text.append(Spaces % Style.TabWidth, ' ');
833 case FormatStyle::UT_ForIndentation:
834 if (WhitespaceStartColumn == 0) {
835 unsigned Indentation = IndentLevel * Style.IndentWidth;
836 // This happens, e.g. when a line in a block comment is indented less than
838 if (Indentation > Spaces)
839 Indentation = Spaces;
840 unsigned Tabs = Indentation / Style.TabWidth;
841 Text.append(Tabs, '\t');
842 Spaces -= Tabs * Style.TabWidth;
844 Text.append(Spaces, ' ');
846 case FormatStyle::UT_ForContinuationAndIndentation:
847 if (WhitespaceStartColumn == 0) {
848 unsigned Tabs = Spaces / Style.TabWidth;
849 Text.append(Tabs, '\t');
850 Spaces -= Tabs * Style.TabWidth;
852 Text.append(Spaces, ' ');
857 } // namespace format