1 //===--- UnwrappedLineFormatter.cpp - Format C++ code ---------------------===//
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 //===----------------------------------------------------------------------===//
10 #include "NamespaceEndCommentsFixer.h"
11 #include "UnwrappedLineFormatter.h"
12 #include "WhitespaceManager.h"
13 #include "llvm/Support/Debug.h"
16 #define DEBUG_TYPE "format-formatter"
23 bool startsExternCBlock(const AnnotatedLine &Line) {
24 const FormatToken *Next = Line.First->getNextNonComment();
25 const FormatToken *NextNext = Next ? Next->getNextNonComment() : nullptr;
26 return Line.startsWith(tok::kw_extern) && Next && Next->isStringLiteral() &&
27 NextNext && NextNext->is(tok::l_brace);
30 /// Tracks the indent level of \c AnnotatedLines across levels.
32 /// \c nextLine must be called for each \c AnnotatedLine, after which \c
33 /// getIndent() will return the indent for the last line \c nextLine was called
35 /// If the line is not formatted (and thus the indent does not change), calling
36 /// \c adjustToUnmodifiedLine after the call to \c nextLine will cause
37 /// subsequent lines on the same level to be indented at the same level as the
39 class LevelIndentTracker {
41 LevelIndentTracker(const FormatStyle &Style,
42 const AdditionalKeywords &Keywords, unsigned StartLevel,
44 : Style(Style), Keywords(Keywords), AdditionalIndent(AdditionalIndent) {
45 for (unsigned i = 0; i != StartLevel; ++i)
46 IndentForLevel.push_back(Style.IndentWidth * i + AdditionalIndent);
49 /// Returns the indent for the current line.
50 unsigned getIndent() const { return Indent; }
52 /// Update the indent state given that \p Line is going to be formatted
54 void nextLine(const AnnotatedLine &Line) {
55 Offset = getIndentOffset(*Line.First);
56 // Update the indent level cache size so that we can rely on it
57 // having the right size in adjustToUnmodifiedline.
58 while (IndentForLevel.size() <= Line.Level)
59 IndentForLevel.push_back(-1);
60 if (Line.InPPDirective) {
61 Indent = Line.Level * Style.IndentWidth + AdditionalIndent;
63 IndentForLevel.resize(Line.Level + 1);
64 Indent = getIndent(IndentForLevel, Line.Level);
66 if (static_cast<int>(Indent) + Offset >= 0)
70 /// Update the indent state given that \p Line indent should be
72 void skipLine(const AnnotatedLine &Line) {
73 while (IndentForLevel.size() <= Line.Level)
74 IndentForLevel.push_back(Indent);
77 /// Update the level indent to adapt to the given \p Line.
79 /// When a line is not formatted, we move the subsequent lines on the same
80 /// level to the same indent.
81 /// Note that \c nextLine must have been called before this method.
82 void adjustToUnmodifiedLine(const AnnotatedLine &Line) {
83 unsigned LevelIndent = Line.First->OriginalColumn;
84 if (static_cast<int>(LevelIndent) - Offset >= 0)
85 LevelIndent -= Offset;
86 if ((!Line.First->is(tok::comment) || IndentForLevel[Line.Level] == -1) &&
88 IndentForLevel[Line.Level] = LevelIndent;
92 /// Get the offset of the line relatively to the level.
94 /// For example, 'public:' labels in classes are offset by 1 or 2
95 /// characters to the left from their level.
96 int getIndentOffset(const FormatToken &RootToken) {
97 if (Style.Language == FormatStyle::LK_Java ||
98 Style.Language == FormatStyle::LK_JavaScript)
100 if (RootToken.isAccessSpecifier(false) ||
101 RootToken.isObjCAccessSpecifier() ||
102 (RootToken.isOneOf(Keywords.kw_signals, Keywords.kw_qsignals) &&
103 RootToken.Next && RootToken.Next->is(tok::colon)))
104 return Style.AccessModifierOffset;
108 /// Get the indent of \p Level from \p IndentForLevel.
110 /// \p IndentForLevel must contain the indent for the level \c l
111 /// at \p IndentForLevel[l], or a value < 0 if the indent for
112 /// that level is unknown.
113 unsigned getIndent(ArrayRef<int> IndentForLevel, unsigned Level) {
114 if (IndentForLevel[Level] != -1)
115 return IndentForLevel[Level];
118 return getIndent(IndentForLevel, Level - 1) + Style.IndentWidth;
121 const FormatStyle &Style;
122 const AdditionalKeywords &Keywords;
123 const unsigned AdditionalIndent;
125 /// The indent in characters for each level.
126 std::vector<int> IndentForLevel;
128 /// Offset of the current line relative to the indent level.
130 /// For example, the 'public' keywords is often indented with a negative
134 /// The current line's indent.
138 bool isNamespaceDeclaration(const AnnotatedLine *Line) {
139 const FormatToken *NamespaceTok = Line->First;
140 return NamespaceTok && NamespaceTok->getNamespaceToken();
143 bool isEndOfNamespace(const AnnotatedLine *Line,
144 const SmallVectorImpl<AnnotatedLine *> &AnnotatedLines) {
145 if (!Line->startsWith(tok::r_brace))
147 size_t StartLineIndex = Line->MatchingOpeningBlockLineIndex;
148 if (StartLineIndex == UnwrappedLine::kInvalidIndex)
150 assert(StartLineIndex < AnnotatedLines.size());
151 return isNamespaceDeclaration(AnnotatedLines[StartLineIndex]);
156 LineJoiner(const FormatStyle &Style, const AdditionalKeywords &Keywords,
157 const SmallVectorImpl<AnnotatedLine *> &Lines)
158 : Style(Style), Keywords(Keywords), End(Lines.end()), Next(Lines.begin()),
159 AnnotatedLines(Lines) {}
161 /// Returns the next line, merging multiple lines into one if possible.
162 const AnnotatedLine *getNextMergedLine(bool DryRun,
163 LevelIndentTracker &IndentTracker) {
166 const AnnotatedLine *Current = *Next;
167 IndentTracker.nextLine(*Current);
168 unsigned MergedLines = tryFitMultipleLinesInOne(IndentTracker, Next, End);
169 if (MergedLines > 0 && Style.ColumnLimit == 0)
170 // Disallow line merging if there is a break at the start of one of the
172 for (unsigned i = 0; i < MergedLines; ++i)
173 if (Next[i + 1]->First->NewlinesBefore > 0)
176 for (unsigned i = 0; i < MergedLines; ++i)
177 join(*Next[0], *Next[i + 1]);
178 Next = Next + MergedLines + 1;
183 /// Calculates how many lines can be merged into 1 starting at \p I.
185 tryFitMultipleLinesInOne(LevelIndentTracker &IndentTracker,
186 SmallVectorImpl<AnnotatedLine *>::const_iterator I,
187 SmallVectorImpl<AnnotatedLine *>::const_iterator E) {
188 const unsigned Indent = IndentTracker.getIndent();
190 // Can't join the last line with anything.
193 // We can never merge stuff if there are trailing line comments.
194 const AnnotatedLine *TheLine = *I;
195 if (TheLine->Last->is(TT_LineComment))
197 if (I[1]->Type == LT_Invalid || I[1]->First->MustBreakBefore)
199 if (TheLine->InPPDirective &&
200 (!I[1]->InPPDirective || I[1]->First->HasUnescapedNewline))
203 if (Style.ColumnLimit > 0 && Indent > Style.ColumnLimit)
207 Style.ColumnLimit == 0 ? UINT_MAX : Style.ColumnLimit - Indent;
208 // If we already exceed the column limit, we set 'Limit' to 0. The different
209 // tryMerge..() functions can then decide whether to still do merging.
210 Limit = TheLine->Last->TotalLength > Limit
212 : Limit - TheLine->Last->TotalLength;
214 if (TheLine->Last->is(TT_FunctionLBrace) &&
215 TheLine->First == TheLine->Last &&
216 !Style.BraceWrapping.SplitEmptyFunction &&
217 I[1]->First->is(tok::r_brace))
218 return tryMergeSimpleBlock(I, E, Limit);
220 // Handle empty record blocks where the brace has already been wrapped
221 if (TheLine->Last->is(tok::l_brace) && TheLine->First == TheLine->Last &&
222 I != AnnotatedLines.begin()) {
223 bool EmptyBlock = I[1]->First->is(tok::r_brace);
225 const FormatToken *Tok = I[-1]->First;
226 if (Tok && Tok->is(tok::comment))
227 Tok = Tok->getNextNonComment();
229 if (Tok && Tok->getNamespaceToken())
230 return !Style.BraceWrapping.SplitEmptyNamespace && EmptyBlock
231 ? tryMergeSimpleBlock(I, E, Limit)
234 if (Tok && Tok->is(tok::kw_typedef))
235 Tok = Tok->getNextNonComment();
236 if (Tok && Tok->isOneOf(tok::kw_class, tok::kw_struct, tok::kw_union,
237 tok::kw_extern, Keywords.kw_interface))
238 return !Style.BraceWrapping.SplitEmptyRecord && EmptyBlock
239 ? tryMergeSimpleBlock(I, E, Limit)
243 // FIXME: TheLine->Level != 0 might or might not be the right check to do.
244 // If necessary, change to something smarter.
245 bool MergeShortFunctions =
246 Style.AllowShortFunctionsOnASingleLine == FormatStyle::SFS_All ||
247 (Style.AllowShortFunctionsOnASingleLine >= FormatStyle::SFS_Empty &&
248 I[1]->First->is(tok::r_brace)) ||
249 (Style.AllowShortFunctionsOnASingleLine & FormatStyle::SFS_InlineOnly &&
250 TheLine->Level != 0);
252 if (Style.CompactNamespaces) {
253 if (isNamespaceDeclaration(TheLine)) {
255 unsigned closingLine = TheLine->MatchingClosingBlockLineIndex - 1;
256 for (; I + 1 + i != E && isNamespaceDeclaration(I[i + 1]) &&
257 closingLine == I[i + 1]->MatchingClosingBlockLineIndex &&
258 I[i + 1]->Last->TotalLength < Limit;
259 i++, closingLine--) {
260 // No extra indent for compacted namespaces
261 IndentTracker.skipLine(*I[i + 1]);
263 Limit -= I[i + 1]->Last->TotalLength;
268 if (isEndOfNamespace(TheLine, AnnotatedLines)) {
270 unsigned openingLine = TheLine->MatchingOpeningBlockLineIndex - 1;
271 for (; I + 1 + i != E && isEndOfNamespace(I[i + 1], AnnotatedLines) &&
272 openingLine == I[i + 1]->MatchingOpeningBlockLineIndex;
273 i++, openingLine--) {
274 // No space between consecutive braces
275 I[i + 1]->First->SpacesRequiredBefore = !I[i]->Last->is(tok::r_brace);
277 // Indent like the outer-most namespace
278 IndentTracker.nextLine(*I[i + 1]);
284 // Try to merge a function block with left brace unwrapped
285 if (TheLine->Last->is(TT_FunctionLBrace) &&
286 TheLine->First != TheLine->Last) {
287 return MergeShortFunctions ? tryMergeSimpleBlock(I, E, Limit) : 0;
289 // Try to merge a control statement block with left brace unwrapped
290 if (TheLine->Last->is(tok::l_brace) && TheLine->First != TheLine->Last &&
291 TheLine->First->isOneOf(tok::kw_if, tok::kw_while, tok::kw_for)) {
292 return Style.AllowShortBlocksOnASingleLine
293 ? tryMergeSimpleBlock(I, E, Limit)
296 // Try to merge a control statement block with left brace wrapped
297 if (I[1]->First->is(tok::l_brace) &&
298 TheLine->First->isOneOf(tok::kw_if, tok::kw_while, tok::kw_for)) {
299 return Style.BraceWrapping.AfterControlStatement
300 ? tryMergeSimpleBlock(I, E, Limit)
303 // Try to merge either empty or one-line block if is precedeed by control
305 if (TheLine->First->is(tok::l_brace) && TheLine->First == TheLine->Last &&
306 I != AnnotatedLines.begin() &&
307 I[-1]->First->isOneOf(tok::kw_if, tok::kw_while, tok::kw_for)) {
308 unsigned MergedLines = 0;
309 if (Style.AllowShortBlocksOnASingleLine) {
310 MergedLines = tryMergeSimpleBlock(I - 1, E, Limit);
311 // If we managed to merge the block, discard the first merged line
312 // since we are merging starting from I.
318 // Don't merge block with left brace wrapped after ObjC special blocks
319 if (TheLine->First->is(tok::l_brace) && I != AnnotatedLines.begin() &&
320 I[-1]->First->is(tok::at) && I[-1]->First->Next) {
321 tok::ObjCKeywordKind kwId = I[-1]->First->Next->Tok.getObjCKeywordID();
322 if (kwId == clang::tok::objc_autoreleasepool ||
323 kwId == clang::tok::objc_synchronized)
326 // Don't merge block with left brace wrapped after case labels
327 if (TheLine->First->is(tok::l_brace) && I != AnnotatedLines.begin() &&
328 I[-1]->First->isOneOf(tok::kw_case, tok::kw_default))
330 // Try to merge a block with left brace wrapped that wasn't yet covered
331 if (TheLine->Last->is(tok::l_brace)) {
332 return !Style.BraceWrapping.AfterFunction ||
333 (I[1]->First->is(tok::r_brace) &&
334 !Style.BraceWrapping.SplitEmptyRecord)
335 ? tryMergeSimpleBlock(I, E, Limit)
338 // Try to merge a function block with left brace wrapped
339 if (I[1]->First->is(TT_FunctionLBrace) &&
340 Style.BraceWrapping.AfterFunction) {
341 if (I[1]->Last->is(TT_LineComment))
344 // Check for Limit <= 2 to account for the " {".
345 if (Limit <= 2 || (Style.ColumnLimit == 0 && containsMustBreak(TheLine)))
349 unsigned MergedLines = 0;
350 if (MergeShortFunctions ||
351 (Style.AllowShortFunctionsOnASingleLine >= FormatStyle::SFS_Empty &&
352 I[1]->First == I[1]->Last && I + 2 != E &&
353 I[2]->First->is(tok::r_brace))) {
354 MergedLines = tryMergeSimpleBlock(I + 1, E, Limit);
355 // If we managed to merge the block, count the function header, which is
356 // on a separate line.
362 if (TheLine->First->is(tok::kw_if)) {
363 return Style.AllowShortIfStatementsOnASingleLine
364 ? tryMergeSimpleControlStatement(I, E, Limit)
367 if (TheLine->First->isOneOf(tok::kw_for, tok::kw_while)) {
368 return Style.AllowShortLoopsOnASingleLine
369 ? tryMergeSimpleControlStatement(I, E, Limit)
372 if (TheLine->First->isOneOf(tok::kw_case, tok::kw_default)) {
373 return Style.AllowShortCaseLabelsOnASingleLine
374 ? tryMergeShortCaseLabels(I, E, Limit)
377 if (TheLine->InPPDirective &&
378 (TheLine->First->HasUnescapedNewline || TheLine->First->IsFirst)) {
379 return tryMergeSimplePPDirective(I, E, Limit);
385 tryMergeSimplePPDirective(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
386 SmallVectorImpl<AnnotatedLine *>::const_iterator E,
390 if (I + 2 != E && I[2]->InPPDirective && !I[2]->First->HasUnescapedNewline)
392 if (1 + I[1]->Last->TotalLength > Limit)
397 unsigned tryMergeSimpleControlStatement(
398 SmallVectorImpl<AnnotatedLine *>::const_iterator I,
399 SmallVectorImpl<AnnotatedLine *>::const_iterator E, unsigned Limit) {
402 if (Style.BraceWrapping.AfterControlStatement &&
403 (I[1]->First->is(tok::l_brace) && !Style.AllowShortBlocksOnASingleLine))
405 if (I[1]->InPPDirective != (*I)->InPPDirective ||
406 (I[1]->InPPDirective && I[1]->First->HasUnescapedNewline))
408 Limit = limitConsideringMacros(I + 1, E, Limit);
409 AnnotatedLine &Line = **I;
410 if (Line.Last->isNot(tok::r_paren))
412 if (1 + I[1]->Last->TotalLength > Limit)
414 if (I[1]->First->isOneOf(tok::semi, tok::kw_if, tok::kw_for, tok::kw_while,
417 // Only inline simple if's (no nested if or else).
418 if (I + 2 != E && Line.startsWith(tok::kw_if) &&
419 I[2]->First->is(tok::kw_else))
425 tryMergeShortCaseLabels(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
426 SmallVectorImpl<AnnotatedLine *>::const_iterator E,
428 if (Limit == 0 || I + 1 == E ||
429 I[1]->First->isOneOf(tok::kw_case, tok::kw_default))
431 if (I[0]->Last->is(tok::l_brace) || I[1]->First->is(tok::l_brace))
433 unsigned NumStmts = 0;
435 bool EndsWithComment = false;
436 bool InPPDirective = I[0]->InPPDirective;
437 const unsigned Level = I[0]->Level;
438 for (; NumStmts < 3; ++NumStmts) {
439 if (I + 1 + NumStmts == E)
441 const AnnotatedLine *Line = I[1 + NumStmts];
442 if (Line->InPPDirective != InPPDirective)
444 if (Line->First->isOneOf(tok::kw_case, tok::kw_default, tok::r_brace))
446 if (Line->First->isOneOf(tok::kw_if, tok::kw_for, tok::kw_switch,
450 if (Line->First->is(tok::comment)) {
451 if (Level != Line->Level)
453 SmallVectorImpl<AnnotatedLine *>::const_iterator J = I + 2 + NumStmts;
454 for (; J != E; ++J) {
456 if (Line->InPPDirective != InPPDirective)
458 if (Line->First->isOneOf(tok::kw_case, tok::kw_default, tok::r_brace))
460 if (Line->First->isNot(tok::comment) || Level != Line->Level)
465 if (Line->Last->is(tok::comment))
466 EndsWithComment = true;
467 Length += I[1 + NumStmts]->Last->TotalLength + 1; // 1 for the space.
469 if (NumStmts == 0 || NumStmts == 3 || Length > Limit)
475 tryMergeSimpleBlock(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
476 SmallVectorImpl<AnnotatedLine *>::const_iterator E,
478 AnnotatedLine &Line = **I;
480 // Don't merge ObjC @ keywords and methods.
481 // FIXME: If an option to allow short exception handling clauses on a single
482 // line is added, change this to not return for @try and friends.
483 if (Style.Language != FormatStyle::LK_Java &&
484 Line.First->isOneOf(tok::at, tok::minus, tok::plus))
487 // Check that the current line allows merging. This depends on whether we
488 // are in a control flow statements as well as several style flags.
489 if (Line.First->isOneOf(tok::kw_else, tok::kw_case) ||
490 (Line.First->Next && Line.First->Next->is(tok::kw_else)))
492 // default: in switch statement
493 if (Line.First->is(tok::kw_default)) {
494 const FormatToken *Tok = Line.First->getNextNonComment();
495 if (Tok && Tok->is(tok::colon))
498 if (Line.First->isOneOf(tok::kw_if, tok::kw_while, tok::kw_do, tok::kw_try,
499 tok::kw___try, tok::kw_catch, tok::kw___finally,
500 tok::kw_for, tok::r_brace, Keywords.kw___except)) {
501 if (!Style.AllowShortBlocksOnASingleLine)
503 // Don't merge when we can't except the case when
504 // the control statement block is empty
505 if (!Style.AllowShortIfStatementsOnASingleLine &&
506 Line.startsWith(tok::kw_if) &&
507 !Style.BraceWrapping.AfterControlStatement &&
508 !I[1]->First->is(tok::r_brace))
510 if (!Style.AllowShortIfStatementsOnASingleLine &&
511 Line.startsWith(tok::kw_if) &&
512 Style.BraceWrapping.AfterControlStatement && I + 2 != E &&
513 !I[2]->First->is(tok::r_brace))
515 if (!Style.AllowShortLoopsOnASingleLine &&
516 Line.First->isOneOf(tok::kw_while, tok::kw_do, tok::kw_for) &&
517 !Style.BraceWrapping.AfterControlStatement &&
518 !I[1]->First->is(tok::r_brace))
520 if (!Style.AllowShortLoopsOnASingleLine &&
521 Line.First->isOneOf(tok::kw_while, tok::kw_do, tok::kw_for) &&
522 Style.BraceWrapping.AfterControlStatement && I + 2 != E &&
523 !I[2]->First->is(tok::r_brace))
525 // FIXME: Consider an option to allow short exception handling clauses on
527 // FIXME: This isn't covered by tests.
528 // FIXME: For catch, __except, __finally the first token on the line
529 // is '}', so this isn't correct here.
530 if (Line.First->isOneOf(tok::kw_try, tok::kw___try, tok::kw_catch,
531 Keywords.kw___except, tok::kw___finally))
535 if (Line.Last->is(tok::l_brace)) {
536 FormatToken *Tok = I[1]->First;
537 if (Tok->is(tok::r_brace) && !Tok->MustBreakBefore &&
538 (Tok->getNextNonComment() == nullptr ||
539 Tok->getNextNonComment()->is(tok::semi))) {
540 // We merge empty blocks even if the line exceeds the column limit.
541 Tok->SpacesRequiredBefore = 0;
542 Tok->CanBreakBefore = true;
544 } else if (Limit != 0 && !Line.startsWithNamespace() &&
545 !startsExternCBlock(Line)) {
546 // We don't merge short records.
547 FormatToken *RecordTok = Line.First;
548 // Skip record modifiers.
549 while (RecordTok->Next &&
550 RecordTok->isOneOf(tok::kw_typedef, tok::kw_export,
551 Keywords.kw_declare, Keywords.kw_abstract,
553 RecordTok = RecordTok->Next;
555 RecordTok->isOneOf(tok::kw_class, tok::kw_union, tok::kw_struct,
556 Keywords.kw_interface))
559 // Check that we still have three lines and they fit into the limit.
560 if (I + 2 == E || I[2]->Type == LT_Invalid)
562 Limit = limitConsideringMacros(I + 2, E, Limit);
564 if (!nextTwoLinesFitInto(I, Limit))
567 // Second, check that the next line does not contain any braces - if it
568 // does, readability declines when putting it into a single line.
569 if (I[1]->Last->is(TT_LineComment))
572 if (Tok->is(tok::l_brace) && Tok->BlockKind != BK_BracedInit)
577 // Last, check that the third line starts with a closing brace.
579 if (Tok->isNot(tok::r_brace))
582 // Don't merge "if (a) { .. } else {".
583 if (Tok->Next && Tok->Next->is(tok::kw_else))
588 } else if (I[1]->First->is(tok::l_brace)) {
589 if (I[1]->Last->is(TT_LineComment))
592 // Check for Limit <= 2 to account for the " {".
593 if (Limit <= 2 || (Style.ColumnLimit == 0 && containsMustBreak(*I)))
596 unsigned MergedLines = 0;
597 if (Style.AllowShortBlocksOnASingleLine ||
598 (I[1]->First == I[1]->Last && I + 2 != E &&
599 I[2]->First->is(tok::r_brace))) {
600 MergedLines = tryMergeSimpleBlock(I + 1, E, Limit);
601 // If we managed to merge the block, count the statement header, which
602 // is on a separate line.
611 /// Returns the modified column limit for \p I if it is inside a macro and
612 /// needs a trailing '\'.
614 limitConsideringMacros(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
615 SmallVectorImpl<AnnotatedLine *>::const_iterator E,
617 if (I[0]->InPPDirective && I + 1 != E &&
618 !I[1]->First->HasUnescapedNewline && !I[1]->First->is(tok::eof)) {
619 return Limit < 2 ? 0 : Limit - 2;
624 bool nextTwoLinesFitInto(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
626 if (I[1]->First->MustBreakBefore || I[2]->First->MustBreakBefore)
628 return 1 + I[1]->Last->TotalLength + 1 + I[2]->Last->TotalLength <= Limit;
631 bool containsMustBreak(const AnnotatedLine *Line) {
632 for (const FormatToken *Tok = Line->First; Tok; Tok = Tok->Next) {
633 if (Tok->MustBreakBefore)
639 void join(AnnotatedLine &A, const AnnotatedLine &B) {
640 assert(!A.Last->Next);
641 assert(!B.First->Previous);
644 A.Last->Next = B.First;
645 B.First->Previous = A.Last;
646 B.First->CanBreakBefore = true;
647 unsigned LengthA = A.Last->TotalLength + B.First->SpacesRequiredBefore;
648 for (FormatToken *Tok = B.First; Tok; Tok = Tok->Next) {
649 Tok->TotalLength += LengthA;
654 const FormatStyle &Style;
655 const AdditionalKeywords &Keywords;
656 const SmallVectorImpl<AnnotatedLine *>::const_iterator End;
658 SmallVectorImpl<AnnotatedLine *>::const_iterator Next;
659 const SmallVectorImpl<AnnotatedLine *> &AnnotatedLines;
662 static void markFinalized(FormatToken *Tok) {
663 for (; Tok; Tok = Tok->Next) {
664 Tok->Finalized = true;
665 for (AnnotatedLine *Child : Tok->Children)
666 markFinalized(Child->First);
671 static void printLineState(const LineState &State) {
672 llvm::dbgs() << "State: ";
673 for (const ParenState &P : State.Stack) {
674 llvm::dbgs() << (P.Tok ? P.Tok->TokenText : "F") << "|" << P.Indent << "|"
675 << P.LastSpace << "|" << P.NestedBlockIndent << " ";
677 llvm::dbgs() << State.NextToken->TokenText << "\n";
681 /// Base class for classes that format one \c AnnotatedLine.
682 class LineFormatter {
684 LineFormatter(ContinuationIndenter *Indenter, WhitespaceManager *Whitespaces,
685 const FormatStyle &Style,
686 UnwrappedLineFormatter *BlockFormatter)
687 : Indenter(Indenter), Whitespaces(Whitespaces), Style(Style),
688 BlockFormatter(BlockFormatter) {}
689 virtual ~LineFormatter() {}
691 /// Formats an \c AnnotatedLine and returns the penalty.
693 /// If \p DryRun is \c false, directly applies the changes.
694 virtual unsigned formatLine(const AnnotatedLine &Line,
695 unsigned FirstIndent,
696 unsigned FirstStartColumn,
700 /// If the \p State's next token is an r_brace closing a nested block,
701 /// format the nested block before it.
703 /// Returns \c true if all children could be placed successfully and adapts
704 /// \p Penalty as well as \p State. If \p DryRun is false, also directly
705 /// creates changes using \c Whitespaces.
707 /// The crucial idea here is that children always get formatted upon
708 /// encountering the closing brace right after the nested block. Now, if we
709 /// are currently trying to keep the "}" on the same line (i.e. \p NewLine is
710 /// \c false), the entire block has to be kept on the same line (which is only
711 /// possible if it fits on the line, only contains a single statement, etc.
713 /// If \p NewLine is true, we format the nested block on separate lines, i.e.
714 /// break after the "{", format all lines with correct indentation and the put
715 /// the closing "}" on yet another new line.
717 /// This enables us to keep the simple structure of the
718 /// \c UnwrappedLineFormatter, where we only have two options for each token:
719 /// break or don't break.
720 bool formatChildren(LineState &State, bool NewLine, bool DryRun,
722 const FormatToken *LBrace = State.NextToken->getPreviousNonComment();
723 FormatToken &Previous = *State.NextToken->Previous;
724 if (!LBrace || LBrace->isNot(tok::l_brace) ||
725 LBrace->BlockKind != BK_Block || Previous.Children.size() == 0)
726 // The previous token does not open a block. Nothing to do. We don't
727 // assert so that we can simply call this function for all tokens.
731 int AdditionalIndent = State.Stack.back().Indent -
732 Previous.Children[0]->Level * Style.IndentWidth;
735 BlockFormatter->format(Previous.Children, DryRun, AdditionalIndent,
736 /*FixBadIndentation=*/true);
740 if (Previous.Children[0]->First->MustBreakBefore)
743 // Cannot merge into one line if this line ends on a comment.
744 if (Previous.is(tok::comment))
747 // Cannot merge multiple statements into a single line.
748 if (Previous.Children.size() > 1)
751 const AnnotatedLine *Child = Previous.Children[0];
752 // We can't put the closing "}" on a line with a trailing comment.
753 if (Child->Last->isTrailingComment())
756 // If the child line exceeds the column limit, we wouldn't want to merge it.
757 // We add +2 for the trailing " }".
758 if (Style.ColumnLimit > 0 &&
759 Child->Last->TotalLength + State.Column + 2 > Style.ColumnLimit)
763 Whitespaces->replaceWhitespace(
764 *Child->First, /*Newlines=*/0, /*Spaces=*/1,
765 /*StartOfTokenColumn=*/State.Column, State.Line->InPPDirective);
768 formatLine(*Child, State.Column + 1, /*FirstStartColumn=*/0, DryRun);
770 State.Column += 1 + Child->Last->TotalLength;
774 ContinuationIndenter *Indenter;
777 WhitespaceManager *Whitespaces;
778 const FormatStyle &Style;
779 UnwrappedLineFormatter *BlockFormatter;
782 /// Formatter that keeps the existing line breaks.
783 class NoColumnLimitLineFormatter : public LineFormatter {
785 NoColumnLimitLineFormatter(ContinuationIndenter *Indenter,
786 WhitespaceManager *Whitespaces,
787 const FormatStyle &Style,
788 UnwrappedLineFormatter *BlockFormatter)
789 : LineFormatter(Indenter, Whitespaces, Style, BlockFormatter) {}
791 /// Formats the line, simply keeping all of the input's line breaking
793 unsigned formatLine(const AnnotatedLine &Line, unsigned FirstIndent,
794 unsigned FirstStartColumn, bool DryRun) override {
796 LineState State = Indenter->getInitialState(FirstIndent, FirstStartColumn,
797 &Line, /*DryRun=*/false);
798 while (State.NextToken) {
800 Indenter->mustBreak(State) ||
801 (Indenter->canBreak(State) && State.NextToken->NewlinesBefore > 0);
802 unsigned Penalty = 0;
803 formatChildren(State, Newline, /*DryRun=*/false, Penalty);
804 Indenter->addTokenToState(State, Newline, /*DryRun=*/false);
810 /// Formatter that puts all tokens into a single line without breaks.
811 class NoLineBreakFormatter : public LineFormatter {
813 NoLineBreakFormatter(ContinuationIndenter *Indenter,
814 WhitespaceManager *Whitespaces, const FormatStyle &Style,
815 UnwrappedLineFormatter *BlockFormatter)
816 : LineFormatter(Indenter, Whitespaces, Style, BlockFormatter) {}
818 /// Puts all tokens into a single line.
819 unsigned formatLine(const AnnotatedLine &Line, unsigned FirstIndent,
820 unsigned FirstStartColumn, bool DryRun) override {
821 unsigned Penalty = 0;
823 Indenter->getInitialState(FirstIndent, FirstStartColumn, &Line, DryRun);
824 while (State.NextToken) {
825 formatChildren(State, /*Newline=*/false, DryRun, Penalty);
826 Indenter->addTokenToState(
827 State, /*Newline=*/State.NextToken->MustBreakBefore, DryRun);
833 /// Finds the best way to break lines.
834 class OptimizingLineFormatter : public LineFormatter {
836 OptimizingLineFormatter(ContinuationIndenter *Indenter,
837 WhitespaceManager *Whitespaces,
838 const FormatStyle &Style,
839 UnwrappedLineFormatter *BlockFormatter)
840 : LineFormatter(Indenter, Whitespaces, Style, BlockFormatter) {}
842 /// Formats the line by finding the best line breaks with line lengths
843 /// below the column limit.
844 unsigned formatLine(const AnnotatedLine &Line, unsigned FirstIndent,
845 unsigned FirstStartColumn, bool DryRun) override {
847 Indenter->getInitialState(FirstIndent, FirstStartColumn, &Line, DryRun);
849 // If the ObjC method declaration does not fit on a line, we should format
850 // it with one arg per line.
851 if (State.Line->Type == LT_ObjCMethodDecl)
852 State.Stack.back().BreakBeforeParameter = true;
854 // Find best solution in solution space.
855 return analyzeSolutionSpace(State, DryRun);
859 struct CompareLineStatePointers {
860 bool operator()(LineState *obj1, LineState *obj2) const {
861 return *obj1 < *obj2;
865 /// A pair of <penalty, count> that is used to prioritize the BFS on.
867 /// In case of equal penalties, we want to prefer states that were inserted
868 /// first. During state generation we make sure that we insert states first
869 /// that break the line as late as possible.
870 typedef std::pair<unsigned, unsigned> OrderedPenalty;
872 /// An edge in the solution space from \c Previous->State to \c State,
873 /// inserting a newline dependent on the \c NewLine.
875 StateNode(const LineState &State, bool NewLine, StateNode *Previous)
876 : State(State), NewLine(NewLine), Previous(Previous) {}
882 /// An item in the prioritized BFS search queue. The \c StateNode's
883 /// \c State has the given \c OrderedPenalty.
884 typedef std::pair<OrderedPenalty, StateNode *> QueueItem;
886 /// The BFS queue type.
887 typedef std::priority_queue<QueueItem, std::vector<QueueItem>,
888 std::greater<QueueItem>>
891 /// Analyze the entire solution space starting from \p InitialState.
893 /// This implements a variant of Dijkstra's algorithm on the graph that spans
894 /// the solution space (\c LineStates are the nodes). The algorithm tries to
895 /// find the shortest path (the one with lowest penalty) from \p InitialState
896 /// to a state where all tokens are placed. Returns the penalty.
898 /// If \p DryRun is \c false, directly applies the changes.
899 unsigned analyzeSolutionSpace(LineState &InitialState, bool DryRun) {
900 std::set<LineState *, CompareLineStatePointers> Seen;
902 // Increasing count of \c StateNode items we have created. This is used to
903 // create a deterministic order independent of the container.
907 // Insert start element into queue.
909 new (Allocator.Allocate()) StateNode(InitialState, false, nullptr);
910 Queue.push(QueueItem(OrderedPenalty(0, Count), Node));
913 unsigned Penalty = 0;
915 // While not empty, take first element and follow edges.
916 while (!Queue.empty()) {
917 Penalty = Queue.top().first.first;
918 StateNode *Node = Queue.top().second;
919 if (!Node->State.NextToken) {
920 LLVM_DEBUG(llvm::dbgs()
921 << "\n---\nPenalty for line: " << Penalty << "\n");
926 // Cut off the analysis of certain solutions if the analysis gets too
927 // complex. See description of IgnoreStackForComparison.
929 Node->State.IgnoreStackForComparison = true;
931 if (!Seen.insert(&Node->State).second)
932 // State already examined with lower penalty.
935 FormatDecision LastFormat = Node->State.NextToken->Decision;
936 if (LastFormat == FD_Unformatted || LastFormat == FD_Continue)
937 addNextStateToQueue(Penalty, Node, /*NewLine=*/false, &Count, &Queue);
938 if (LastFormat == FD_Unformatted || LastFormat == FD_Break)
939 addNextStateToQueue(Penalty, Node, /*NewLine=*/true, &Count, &Queue);
943 // We were unable to find a solution, do nothing.
944 // FIXME: Add diagnostic?
945 LLVM_DEBUG(llvm::dbgs() << "Could not find a solution.\n");
949 // Reconstruct the solution.
951 reconstructPath(InitialState, Queue.top().second);
953 LLVM_DEBUG(llvm::dbgs()
954 << "Total number of analyzed states: " << Count << "\n");
955 LLVM_DEBUG(llvm::dbgs() << "---\n");
960 /// Add the following state to the analysis queue \c Queue.
962 /// Assume the current state is \p PreviousNode and has been reached with a
963 /// penalty of \p Penalty. Insert a line break if \p NewLine is \c true.
964 void addNextStateToQueue(unsigned Penalty, StateNode *PreviousNode,
965 bool NewLine, unsigned *Count, QueueType *Queue) {
966 if (NewLine && !Indenter->canBreak(PreviousNode->State))
968 if (!NewLine && Indenter->mustBreak(PreviousNode->State))
971 StateNode *Node = new (Allocator.Allocate())
972 StateNode(PreviousNode->State, NewLine, PreviousNode);
973 if (!formatChildren(Node->State, NewLine, /*DryRun=*/true, Penalty))
976 Penalty += Indenter->addTokenToState(Node->State, NewLine, true);
978 Queue->push(QueueItem(OrderedPenalty(Penalty, *Count), Node));
982 /// Applies the best formatting by reconstructing the path in the
983 /// solution space that leads to \c Best.
984 void reconstructPath(LineState &State, StateNode *Best) {
985 std::deque<StateNode *> Path;
986 // We do not need a break before the initial token.
987 while (Best->Previous) {
988 Path.push_front(Best);
989 Best = Best->Previous;
991 for (auto I = Path.begin(), E = Path.end(); I != E; ++I) {
992 unsigned Penalty = 0;
993 formatChildren(State, (*I)->NewLine, /*DryRun=*/false, Penalty);
994 Penalty += Indenter->addTokenToState(State, (*I)->NewLine, false);
997 printLineState((*I)->Previous->State);
999 llvm::dbgs() << "Penalty for placing "
1000 << (*I)->Previous->State.NextToken->Tok.getName()
1001 << " on a new line: " << Penalty << "\n";
1007 llvm::SpecificBumpPtrAllocator<StateNode> Allocator;
1010 } // anonymous namespace
1013 UnwrappedLineFormatter::format(const SmallVectorImpl<AnnotatedLine *> &Lines,
1014 bool DryRun, int AdditionalIndent,
1015 bool FixBadIndentation,
1016 unsigned FirstStartColumn,
1017 unsigned NextStartColumn,
1018 unsigned LastStartColumn) {
1019 LineJoiner Joiner(Style, Keywords, Lines);
1021 // Try to look up already computed penalty in DryRun-mode.
1022 std::pair<const SmallVectorImpl<AnnotatedLine *> *, unsigned> CacheKey(
1023 &Lines, AdditionalIndent);
1024 auto CacheIt = PenaltyCache.find(CacheKey);
1025 if (DryRun && CacheIt != PenaltyCache.end())
1026 return CacheIt->second;
1028 assert(!Lines.empty());
1029 unsigned Penalty = 0;
1030 LevelIndentTracker IndentTracker(Style, Keywords, Lines[0]->Level,
1032 const AnnotatedLine *PreviousLine = nullptr;
1033 const AnnotatedLine *NextLine = nullptr;
1035 // The minimum level of consecutive lines that have been formatted.
1036 unsigned RangeMinLevel = UINT_MAX;
1038 bool FirstLine = true;
1039 for (const AnnotatedLine *Line =
1040 Joiner.getNextMergedLine(DryRun, IndentTracker);
1041 Line; Line = NextLine, FirstLine = false) {
1042 const AnnotatedLine &TheLine = *Line;
1043 unsigned Indent = IndentTracker.getIndent();
1045 // We continue formatting unchanged lines to adjust their indent, e.g. if a
1046 // scope was added. However, we need to carefully stop doing this when we
1047 // exit the scope of affected lines to prevent indenting a the entire
1048 // remaining file if it currently missing a closing brace.
1049 bool PreviousRBrace =
1050 PreviousLine && PreviousLine->startsWith(tok::r_brace);
1051 bool ContinueFormatting =
1052 TheLine.Level > RangeMinLevel ||
1053 (TheLine.Level == RangeMinLevel && !PreviousRBrace &&
1054 !TheLine.startsWith(tok::r_brace));
1056 bool FixIndentation = (FixBadIndentation || ContinueFormatting) &&
1057 Indent != TheLine.First->OriginalColumn;
1058 bool ShouldFormat = TheLine.Affected || FixIndentation;
1059 // We cannot format this line; if the reason is that the line had a
1060 // parsing error, remember that.
1061 if (ShouldFormat && TheLine.Type == LT_Invalid && Status) {
1062 Status->FormatComplete = false;
1064 SourceMgr.getSpellingLineNumber(TheLine.First->Tok.getLocation());
1067 if (ShouldFormat && TheLine.Type != LT_Invalid) {
1069 bool LastLine = Line->First->is(tok::eof);
1070 formatFirstToken(TheLine, PreviousLine, Lines, Indent,
1071 LastLine ? LastStartColumn : NextStartColumn + Indent);
1074 NextLine = Joiner.getNextMergedLine(DryRun, IndentTracker);
1075 unsigned ColumnLimit = getColumnLimit(TheLine.InPPDirective, NextLine);
1076 bool FitsIntoOneLine =
1077 TheLine.Last->TotalLength + Indent <= ColumnLimit ||
1078 (TheLine.Type == LT_ImportStatement &&
1079 (Style.Language != FormatStyle::LK_JavaScript ||
1080 !Style.JavaScriptWrapImports));
1081 if (Style.ColumnLimit == 0)
1082 NoColumnLimitLineFormatter(Indenter, Whitespaces, Style, this)
1083 .formatLine(TheLine, NextStartColumn + Indent,
1084 FirstLine ? FirstStartColumn : 0, DryRun);
1085 else if (FitsIntoOneLine)
1086 Penalty += NoLineBreakFormatter(Indenter, Whitespaces, Style, this)
1087 .formatLine(TheLine, NextStartColumn + Indent,
1088 FirstLine ? FirstStartColumn : 0, DryRun);
1090 Penalty += OptimizingLineFormatter(Indenter, Whitespaces, Style, this)
1091 .formatLine(TheLine, NextStartColumn + Indent,
1092 FirstLine ? FirstStartColumn : 0, DryRun);
1093 RangeMinLevel = std::min(RangeMinLevel, TheLine.Level);
1095 // If no token in the current line is affected, we still need to format
1096 // affected children.
1097 if (TheLine.ChildrenAffected)
1098 for (const FormatToken *Tok = TheLine.First; Tok; Tok = Tok->Next)
1099 if (!Tok->Children.empty())
1100 format(Tok->Children, DryRun);
1102 // Adapt following lines on the current indent level to the same level
1103 // unless the current \c AnnotatedLine is not at the beginning of a line.
1104 bool StartsNewLine =
1105 TheLine.First->NewlinesBefore > 0 || TheLine.First->IsFirst;
1107 IndentTracker.adjustToUnmodifiedLine(TheLine);
1109 bool ReformatLeadingWhitespace =
1110 StartsNewLine && ((PreviousLine && PreviousLine->Affected) ||
1111 TheLine.LeadingEmptyLinesAffected);
1112 // Format the first token.
1113 if (ReformatLeadingWhitespace)
1114 formatFirstToken(TheLine, PreviousLine, Lines,
1115 TheLine.First->OriginalColumn,
1116 TheLine.First->OriginalColumn);
1118 Whitespaces->addUntouchableToken(*TheLine.First,
1119 TheLine.InPPDirective);
1121 // Notify the WhitespaceManager about the unchanged whitespace.
1122 for (FormatToken *Tok = TheLine.First->Next; Tok; Tok = Tok->Next)
1123 Whitespaces->addUntouchableToken(*Tok, TheLine.InPPDirective);
1125 NextLine = Joiner.getNextMergedLine(DryRun, IndentTracker);
1126 RangeMinLevel = UINT_MAX;
1129 markFinalized(TheLine.First);
1130 PreviousLine = &TheLine;
1132 PenaltyCache[CacheKey] = Penalty;
1136 void UnwrappedLineFormatter::formatFirstToken(
1137 const AnnotatedLine &Line, const AnnotatedLine *PreviousLine,
1138 const SmallVectorImpl<AnnotatedLine *> &Lines, unsigned Indent,
1139 unsigned NewlineIndent) {
1140 FormatToken &RootToken = *Line.First;
1141 if (RootToken.is(tok::eof)) {
1142 unsigned Newlines = std::min(RootToken.NewlinesBefore, 1u);
1143 unsigned TokenIndent = Newlines ? NewlineIndent : 0;
1144 Whitespaces->replaceWhitespace(RootToken, Newlines, TokenIndent,
1149 std::min(RootToken.NewlinesBefore, Style.MaxEmptyLinesToKeep + 1);
1150 // Remove empty lines before "}" where applicable.
1151 if (RootToken.is(tok::r_brace) &&
1153 (RootToken.Next->is(tok::semi) && !RootToken.Next->Next)) &&
1154 // Do not remove empty lines before namespace closing "}".
1155 !getNamespaceToken(&Line, Lines))
1156 Newlines = std::min(Newlines, 1u);
1157 // Remove empty lines at the start of nested blocks (lambdas/arrow functions)
1158 if (PreviousLine == nullptr && Line.Level > 0)
1159 Newlines = std::min(Newlines, 1u);
1160 if (Newlines == 0 && !RootToken.IsFirst)
1162 if (RootToken.IsFirst && !RootToken.HasUnescapedNewline)
1165 // Remove empty lines after "{".
1166 if (!Style.KeepEmptyLinesAtTheStartOfBlocks && PreviousLine &&
1167 PreviousLine->Last->is(tok::l_brace) &&
1168 !PreviousLine->startsWithNamespace() &&
1169 !startsExternCBlock(*PreviousLine))
1172 // Insert extra new line before access specifiers.
1173 if (PreviousLine && PreviousLine->Last->isOneOf(tok::semi, tok::r_brace) &&
1174 RootToken.isAccessSpecifier() && RootToken.NewlinesBefore == 1)
1177 // Remove empty lines after access specifiers.
1178 if (PreviousLine && PreviousLine->First->isAccessSpecifier() &&
1179 (!PreviousLine->InPPDirective || !RootToken.HasUnescapedNewline))
1180 Newlines = std::min(1u, Newlines);
1183 Indent = NewlineIndent;
1185 // Preprocessor directives get indented after the hash, if indented.
1186 if (Line.Type == LT_PreprocessorDirective || Line.Type == LT_ImportStatement)
1189 Whitespaces->replaceWhitespace(RootToken, Newlines, Indent, Indent,
1190 Line.InPPDirective &&
1191 !RootToken.HasUnescapedNewline);
1195 UnwrappedLineFormatter::getColumnLimit(bool InPPDirective,
1196 const AnnotatedLine *NextLine) const {
1197 // In preprocessor directives reserve two chars for trailing " \" if the
1198 // next line continues the preprocessor directive.
1199 bool ContinuesPPDirective =
1201 // If there is no next line, this is likely a child line and the parent
1202 // continues the preprocessor directive.
1204 (NextLine->InPPDirective &&
1205 // If there is an unescaped newline between this line and the next, the
1206 // next line starts a new preprocessor directive.
1207 !NextLine->First->HasUnescapedNewline));
1208 return Style.ColumnLimit - (ContinuesPPDirective ? 2 : 0);
1211 } // namespace format
1212 } // namespace clang