1 //===--- ContinuationIndenter.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 //===----------------------------------------------------------------------===//
11 /// \brief This file implements the continuation indenter.
13 //===----------------------------------------------------------------------===//
15 #include "BreakableToken.h"
16 #include "ContinuationIndenter.h"
17 #include "WhitespaceManager.h"
18 #include "clang/Basic/OperatorPrecedence.h"
19 #include "clang/Basic/SourceManager.h"
20 #include "clang/Format/Format.h"
21 #include "llvm/Support/Debug.h"
24 #define DEBUG_TYPE "format-formatter"
29 // Returns the length of everything up to the first possible line break after
30 // the ), ], } or > matching \c Tok.
31 static unsigned getLengthToMatchingParen(const FormatToken &Tok) {
32 if (!Tok.MatchingParen)
34 FormatToken *End = Tok.MatchingParen;
35 while (End->Next && !End->Next->CanBreakBefore) {
38 return End->TotalLength - Tok.TotalLength + 1;
41 // Returns \c true if \c Tok is the "." or "->" of a call and starts the next
42 // segment of a builder type call.
43 static bool startsSegmentOfBuilderTypeCall(const FormatToken &Tok) {
44 return Tok.isMemberAccess() && Tok.Previous && Tok.Previous->closesScope();
47 // Returns \c true if \c Current starts a new parameter.
48 static bool startsNextParameter(const FormatToken &Current,
49 const FormatStyle &Style) {
50 const FormatToken &Previous = *Current.Previous;
51 if (Current.Type == TT_CtorInitializerComma &&
52 Style.BreakConstructorInitializersBeforeComma)
54 return Previous.is(tok::comma) && !Current.isTrailingComment() &&
55 (Previous.Type != TT_CtorInitializerComma ||
56 !Style.BreakConstructorInitializersBeforeComma);
59 ContinuationIndenter::ContinuationIndenter(const FormatStyle &Style,
60 SourceManager &SourceMgr,
61 WhitespaceManager &Whitespaces,
62 encoding::Encoding Encoding,
63 bool BinPackInconclusiveFunctions)
64 : Style(Style), SourceMgr(SourceMgr), Whitespaces(Whitespaces),
66 BinPackInconclusiveFunctions(BinPackInconclusiveFunctions),
67 CommentPragmasRegex(Style.CommentPragmas) {}
69 LineState ContinuationIndenter::getInitialState(unsigned FirstIndent,
70 const AnnotatedLine *Line,
73 State.FirstIndent = FirstIndent;
74 State.Column = FirstIndent;
76 State.NextToken = Line->First;
77 State.Stack.push_back(ParenState(FirstIndent, Line->Level, FirstIndent,
78 /*AvoidBinPacking=*/false,
79 /*NoLineBreak=*/false));
80 State.LineContainsContinuedForLoopSection = false;
81 State.StartOfStringLiteral = 0;
82 State.StartOfLineLevel = 0;
83 State.LowestLevelOnLine = 0;
84 State.IgnoreStackForComparison = false;
86 // The first token has already been indented and thus consumed.
87 moveStateToNextToken(State, DryRun, /*Newline=*/false);
91 bool ContinuationIndenter::canBreak(const LineState &State) {
92 const FormatToken &Current = *State.NextToken;
93 const FormatToken &Previous = *Current.Previous;
94 assert(&Previous == Current.Previous);
95 if (!Current.CanBreakBefore && !(State.Stack.back().BreakBeforeClosingBrace &&
96 Current.closesBlockTypeList(Style)))
98 // The opening "{" of a braced list has to be on the same line as the first
99 // element if it is nested in another braced init list or function call.
100 if (!Current.MustBreakBefore && Previous.is(tok::l_brace) &&
101 Previous.Type != TT_DictLiteral && Previous.BlockKind == BK_BracedInit &&
103 Previous.Previous->isOneOf(tok::l_brace, tok::l_paren, tok::comma))
105 // This prevents breaks like:
107 // SomeParameter, OtherParameter).DoSomething(
109 // As they hide "DoSomething" and are generally bad for readability.
110 if (Previous.opensScope() && Previous.isNot(tok::l_brace) &&
111 State.LowestLevelOnLine < State.StartOfLineLevel &&
112 State.LowestLevelOnLine < Current.NestingLevel)
114 if (Current.isMemberAccess() && State.Stack.back().ContainsUnwrappedBuilder)
117 // Don't create a 'hanging' indent if there are multiple blocks in a single
119 if (Style.Language == FormatStyle::LK_JavaScript &&
120 Previous.is(tok::l_brace) && State.Stack.size() > 1 &&
121 State.Stack[State.Stack.size() - 2].JSFunctionInlined &&
122 State.Stack[State.Stack.size() - 2].HasMultipleNestedBlocks)
125 return !State.Stack.back().NoLineBreak;
128 bool ContinuationIndenter::mustBreak(const LineState &State) {
129 const FormatToken &Current = *State.NextToken;
130 const FormatToken &Previous = *Current.Previous;
131 if (Current.MustBreakBefore || Current.Type == TT_InlineASMColon)
133 if (State.Stack.back().BreakBeforeClosingBrace &&
134 Current.closesBlockTypeList(Style))
136 if (Previous.is(tok::semi) && State.LineContainsContinuedForLoopSection)
138 if ((startsNextParameter(Current, Style) || Previous.is(tok::semi) ||
139 (Style.BreakBeforeTernaryOperators &&
140 (Current.is(tok::question) || (Current.Type == TT_ConditionalExpr &&
141 Previous.isNot(tok::question)))) ||
142 (!Style.BreakBeforeTernaryOperators &&
143 (Previous.is(tok::question) || Previous.Type == TT_ConditionalExpr))) &&
144 State.Stack.back().BreakBeforeParameter && !Current.isTrailingComment() &&
145 !Current.isOneOf(tok::r_paren, tok::r_brace))
147 if (Style.AlwaysBreakBeforeMultilineStrings &&
148 State.Column > State.Stack.back().Indent && // Breaking saves columns.
149 !Previous.isOneOf(tok::kw_return, tok::lessless, tok::at) &&
150 Previous.Type != TT_InlineASMColon &&
151 Previous.Type != TT_ConditionalExpr && nextIsMultilineString(State))
153 if (((Previous.Type == TT_DictLiteral && Previous.is(tok::l_brace)) ||
154 Previous.Type == TT_ArrayInitializerLSquare) &&
155 Style.ColumnLimit > 0 &&
156 getLengthToMatchingParen(Previous) + State.Column > getColumnLimit(State))
158 if (Current.Type == TT_CtorInitializerColon &&
159 ((Style.AllowShortFunctionsOnASingleLine != FormatStyle::SFS_All) ||
160 Style.BreakConstructorInitializersBeforeComma || Style.ColumnLimit != 0))
163 if (State.Column < getNewLineColumn(State))
165 if (!Style.BreakBeforeBinaryOperators) {
166 // If we need to break somewhere inside the LHS of a binary expression, we
167 // should also break after the operator. Otherwise, the formatting would
168 // hide the operator precedence, e.g. in:
169 // if (aaaaaaaaaaaaaa ==
170 // bbbbbbbbbbbbbb && c) {..
171 // For comparisons, we only apply this rule, if the LHS is a binary
172 // expression itself as otherwise, the line breaks seem superfluous.
173 // We need special cases for ">>" which we have split into two ">" while
174 // lexing in order to make template parsing easier.
176 // FIXME: We'll need something similar for styles that break before binary
178 bool IsComparison = (Previous.getPrecedence() == prec::Relational ||
179 Previous.getPrecedence() == prec::Equality) &&
181 Previous.Previous->Type != TT_BinaryOperator; // For >>.
182 bool LHSIsBinaryExpr =
183 Previous.Previous && Previous.Previous->EndsBinaryExpression;
184 if (Previous.Type == TT_BinaryOperator &&
185 (!IsComparison || LHSIsBinaryExpr) &&
186 Current.Type != TT_BinaryOperator && // For >>.
187 !Current.isTrailingComment() && !Previous.is(tok::lessless) &&
188 Previous.getPrecedence() != prec::Assignment &&
189 State.Stack.back().BreakBeforeParameter)
193 // Same as above, but for the first "<<" operator.
194 if (Current.is(tok::lessless) && Current.Type != TT_OverloadedOperator &&
195 State.Stack.back().BreakBeforeParameter &&
196 State.Stack.back().FirstLessLess == 0)
199 if (Current.Type == TT_SelectorName &&
200 State.Stack.back().ObjCSelectorNameFound &&
201 State.Stack.back().BreakBeforeParameter)
203 if (Previous.ClosesTemplateDeclaration && Current.NestingLevel == 0 &&
204 !Current.isTrailingComment())
207 // If the return type spans multiple lines, wrap before the function name.
208 if ((Current.Type == TT_FunctionDeclarationName ||
209 Current.is(tok::kw_operator)) &&
210 State.Stack.back().BreakBeforeParameter)
213 if (startsSegmentOfBuilderTypeCall(Current) &&
214 (State.Stack.back().CallContinuation != 0 ||
215 (State.Stack.back().BreakBeforeParameter &&
216 State.Stack.back().ContainsUnwrappedBuilder)))
219 // The following could be precomputed as they do not depend on the state.
220 // However, as they should take effect only if the UnwrappedLine does not fit
221 // into the ColumnLimit, they are checked here in the ContinuationIndenter.
222 if (Style.ColumnLimit != 0 && Previous.BlockKind == BK_Block &&
223 Previous.is(tok::l_brace) && !Current.isOneOf(tok::r_brace, tok::comment))
229 unsigned ContinuationIndenter::addTokenToState(LineState &State, bool Newline,
231 unsigned ExtraSpaces) {
232 const FormatToken &Current = *State.NextToken;
234 assert(!State.Stack.empty());
235 if ((Current.Type == TT_ImplicitStringLiteral &&
236 (Current.Previous->Tok.getIdentifierInfo() == nullptr ||
237 Current.Previous->Tok.getIdentifierInfo()->getPPKeywordID() ==
238 tok::pp_not_keyword))) {
239 // FIXME: Is this correct?
240 int WhitespaceLength = SourceMgr.getSpellingColumnNumber(
241 State.NextToken->WhitespaceRange.getEnd()) -
242 SourceMgr.getSpellingColumnNumber(
243 State.NextToken->WhitespaceRange.getBegin());
244 State.Column += WhitespaceLength;
245 moveStateToNextToken(State, DryRun, /*Newline=*/false);
249 unsigned Penalty = 0;
251 Penalty = addTokenOnNewLine(State, DryRun);
253 addTokenOnCurrentLine(State, DryRun, ExtraSpaces);
255 return moveStateToNextToken(State, DryRun, Newline) + Penalty;
258 void ContinuationIndenter::addTokenOnCurrentLine(LineState &State, bool DryRun,
259 unsigned ExtraSpaces) {
260 FormatToken &Current = *State.NextToken;
261 const FormatToken &Previous = *State.NextToken->Previous;
262 if (Current.is(tok::equal) &&
263 (State.Line->First->is(tok::kw_for) || Current.NestingLevel == 0) &&
264 State.Stack.back().VariablePos == 0) {
265 State.Stack.back().VariablePos = State.Column;
266 // Move over * and & if they are bound to the variable name.
267 const FormatToken *Tok = &Previous;
268 while (Tok && State.Stack.back().VariablePos >= Tok->ColumnWidth) {
269 State.Stack.back().VariablePos -= Tok->ColumnWidth;
270 if (Tok->SpacesRequiredBefore != 0)
274 if (Previous.PartOfMultiVariableDeclStmt)
275 State.Stack.back().LastSpace = State.Stack.back().VariablePos;
278 unsigned Spaces = Current.SpacesRequiredBefore + ExtraSpaces;
281 Whitespaces.replaceWhitespace(Current, /*Newlines=*/0, /*IndentLevel=*/0,
282 Spaces, State.Column + Spaces);
284 if (Current.Type == TT_SelectorName &&
285 !State.Stack.back().ObjCSelectorNameFound) {
286 if (Current.LongestObjCSelectorName == 0)
287 State.Stack.back().AlignColons = false;
288 else if (State.Stack.back().Indent + Current.LongestObjCSelectorName >
289 State.Column + Spaces + Current.ColumnWidth)
290 State.Stack.back().ColonPos =
291 State.Stack.back().Indent + Current.LongestObjCSelectorName;
293 State.Stack.back().ColonPos = State.Column + Spaces + Current.ColumnWidth;
296 if (Previous.opensScope() && Previous.Type != TT_ObjCMethodExpr &&
297 (Current.Type != TT_LineComment || Previous.BlockKind == BK_BracedInit))
298 State.Stack.back().Indent = State.Column + Spaces;
299 if (State.Stack.back().AvoidBinPacking && startsNextParameter(Current, Style))
300 State.Stack.back().NoLineBreak = true;
301 if (startsSegmentOfBuilderTypeCall(Current))
302 State.Stack.back().ContainsUnwrappedBuilder = true;
304 State.Column += Spaces;
305 if (Current.isNot(tok::comment) && Previous.is(tok::l_paren) &&
306 Previous.Previous && Previous.Previous->isOneOf(tok::kw_if, tok::kw_for))
307 // Treat the condition inside an if as if it was a second function
308 // parameter, i.e. let nested calls have a continuation indent.
309 State.Stack.back().LastSpace = State.Column;
310 else if (!Current.isOneOf(tok::comment, tok::caret) &&
311 (Previous.is(tok::comma) ||
312 (Previous.is(tok::colon) && Previous.Type == TT_ObjCMethodExpr)))
313 State.Stack.back().LastSpace = State.Column;
314 else if ((Previous.Type == TT_BinaryOperator ||
315 Previous.Type == TT_ConditionalExpr ||
316 Previous.Type == TT_CtorInitializerColon) &&
317 ((Previous.getPrecedence() != prec::Assignment &&
318 (Previous.isNot(tok::lessless) || Previous.OperatorIndex != 0 ||
319 !Previous.LastOperator)) ||
320 Current.StartsBinaryExpression))
321 // Always indent relative to the RHS of the expression unless this is a
322 // simple assignment without binary expression on the RHS. Also indent
323 // relative to unary operators and the colons of constructor initializers.
324 State.Stack.back().LastSpace = State.Column;
325 else if (Previous.Type == TT_InheritanceColon) {
326 State.Stack.back().Indent = State.Column;
327 State.Stack.back().LastSpace = State.Column;
328 } else if (Previous.opensScope()) {
329 // If a function has a trailing call, indent all parameters from the
330 // opening parenthesis. This avoids confusing indents like:
331 // OuterFunction(InnerFunctionCall( // break
332 // ParameterToInnerFunction)) // break
333 // .SecondInnerFunctionCall();
334 bool HasTrailingCall = false;
335 if (Previous.MatchingParen) {
336 const FormatToken *Next = Previous.MatchingParen->getNextNonComment();
337 HasTrailingCall = Next && Next->isMemberAccess();
339 if (HasTrailingCall &&
340 State.Stack[State.Stack.size() - 2].CallContinuation == 0)
341 State.Stack.back().LastSpace = State.Column;
345 unsigned ContinuationIndenter::addTokenOnNewLine(LineState &State,
347 FormatToken &Current = *State.NextToken;
348 const FormatToken &Previous = *State.NextToken->Previous;
350 // Extra penalty that needs to be added because of the way certain line
351 // breaks are chosen.
352 unsigned Penalty = 0;
354 const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
355 const FormatToken *NextNonComment = Previous.getNextNonComment();
357 NextNonComment = &Current;
358 // The first line break on any NestingLevel causes an extra penalty in order
359 // prefer similar line breaks.
360 if (!State.Stack.back().ContainsLineBreak)
362 State.Stack.back().ContainsLineBreak = true;
364 Penalty += State.NextToken->SplitPenalty;
366 // Breaking before the first "<<" is generally not desirable if the LHS is
367 // short. Also always add the penalty if the LHS is split over mutliple lines
368 // to avoid unnecessary line breaks that just work around this penalty.
369 if (NextNonComment->is(tok::lessless) &&
370 State.Stack.back().FirstLessLess == 0 &&
371 (State.Column <= Style.ColumnLimit / 3 ||
372 State.Stack.back().BreakBeforeParameter))
373 Penalty += Style.PenaltyBreakFirstLessLess;
375 State.Column = getNewLineColumn(State);
376 if (NextNonComment->isMemberAccess()) {
377 if (State.Stack.back().CallContinuation == 0)
378 State.Stack.back().CallContinuation = State.Column;
379 } else if (NextNonComment->Type == TT_SelectorName) {
380 if (!State.Stack.back().ObjCSelectorNameFound) {
381 if (NextNonComment->LongestObjCSelectorName == 0) {
382 State.Stack.back().AlignColons = false;
384 State.Stack.back().ColonPos =
385 State.Stack.back().Indent + NextNonComment->LongestObjCSelectorName;
387 } else if (State.Stack.back().AlignColons &&
388 State.Stack.back().ColonPos <= NextNonComment->ColumnWidth) {
389 State.Stack.back().ColonPos = State.Column + NextNonComment->ColumnWidth;
391 } else if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
392 (PreviousNonComment->Type == TT_ObjCMethodExpr ||
393 PreviousNonComment->Type == TT_DictLiteral)) {
394 // FIXME: This is hacky, find a better way. The problem is that in an ObjC
395 // method expression, the block should be aligned to the line starting it,
397 // [aaaaaaaaaaaaaaa aaaaaaaaa: \\ break for some reason
401 // Thus, we set LastSpace of the next higher NestingLevel, to which we move
402 // when we consume all of the "}"'s FakeRParens at the "{".
403 if (State.Stack.size() > 1)
404 State.Stack[State.Stack.size() - 2].LastSpace =
405 std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) +
406 Style.ContinuationIndentWidth;
409 if ((Previous.isOneOf(tok::comma, tok::semi) &&
410 !State.Stack.back().AvoidBinPacking) ||
411 Previous.Type == TT_BinaryOperator)
412 State.Stack.back().BreakBeforeParameter = false;
413 if (Previous.Type == TT_TemplateCloser && Current.NestingLevel == 0)
414 State.Stack.back().BreakBeforeParameter = false;
415 if (NextNonComment->is(tok::question) ||
416 (PreviousNonComment && PreviousNonComment->is(tok::question)))
417 State.Stack.back().BreakBeforeParameter = true;
420 unsigned Newlines = std::max(
421 1u, std::min(Current.NewlinesBefore, Style.MaxEmptyLinesToKeep + 1));
422 Whitespaces.replaceWhitespace(Current, Newlines,
423 State.Stack.back().IndentLevel, State.Column,
424 State.Column, State.Line->InPPDirective);
427 if (!Current.isTrailingComment())
428 State.Stack.back().LastSpace = State.Column;
429 State.StartOfLineLevel = Current.NestingLevel;
430 State.LowestLevelOnLine = Current.NestingLevel;
432 // Any break on this level means that the parent level has been broken
433 // and we need to avoid bin packing there.
434 bool JavaScriptFormat = Style.Language == FormatStyle::LK_JavaScript &&
435 Current.is(tok::r_brace) &&
436 State.Stack.size() > 1 &&
437 State.Stack[State.Stack.size() - 2].JSFunctionInlined;
438 if (!JavaScriptFormat) {
439 for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i) {
440 State.Stack[i].BreakBeforeParameter = true;
444 if (PreviousNonComment &&
445 !PreviousNonComment->isOneOf(tok::comma, tok::semi) &&
446 PreviousNonComment->Type != TT_TemplateCloser &&
447 PreviousNonComment->Type != TT_BinaryOperator &&
448 Current.Type != TT_BinaryOperator && !PreviousNonComment->opensScope())
449 State.Stack.back().BreakBeforeParameter = true;
451 // If we break after { or the [ of an array initializer, we should also break
452 // before the corresponding } or ].
453 if (PreviousNonComment &&
454 (PreviousNonComment->is(tok::l_brace) ||
455 PreviousNonComment->Type == TT_ArrayInitializerLSquare))
456 State.Stack.back().BreakBeforeClosingBrace = true;
458 if (State.Stack.back().AvoidBinPacking) {
459 // If we are breaking after '(', '{', '<', this is not bin packing
460 // unless AllowAllParametersOfDeclarationOnNextLine is false or this is a
461 // dict/object literal.
462 if (!(Previous.isOneOf(tok::l_paren, tok::l_brace) ||
463 Previous.Type == TT_BinaryOperator) ||
464 (!Style.AllowAllParametersOfDeclarationOnNextLine &&
465 State.Line->MustBeDeclaration) ||
466 Previous.Type == TT_DictLiteral)
467 State.Stack.back().BreakBeforeParameter = true;
473 unsigned ContinuationIndenter::getNewLineColumn(const LineState &State) {
474 if (!State.NextToken || !State.NextToken->Previous)
476 FormatToken &Current = *State.NextToken;
477 const FormatToken &Previous = *State.NextToken->Previous;
478 // If we are continuing an expression, we want to use the continuation indent.
479 unsigned ContinuationIndent =
480 std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) +
481 Style.ContinuationIndentWidth;
482 const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
483 const FormatToken *NextNonComment = Previous.getNextNonComment();
485 NextNonComment = &Current;
486 if (NextNonComment->is(tok::l_brace) && NextNonComment->BlockKind == BK_Block)
487 return Current.NestingLevel == 0 ? State.FirstIndent
488 : State.Stack.back().Indent;
489 if (Current.isOneOf(tok::r_brace, tok::r_square)) {
490 if (State.Stack.size() > 1 &&
491 State.Stack[State.Stack.size() - 2].JSFunctionInlined)
492 return State.FirstIndent;
493 if (Current.closesBlockTypeList(Style) ||
494 (Current.MatchingParen &&
495 Current.MatchingParen->BlockKind == BK_BracedInit))
496 return State.Stack[State.Stack.size() - 2].LastSpace;
498 return State.FirstIndent;
500 if (Current.is(tok::identifier) && Current.Next &&
501 Current.Next->Type == TT_DictLiteral)
502 return State.Stack.back().Indent;
503 if (NextNonComment->isStringLiteral() && State.StartOfStringLiteral != 0)
504 return State.StartOfStringLiteral;
505 if (NextNonComment->is(tok::lessless) &&
506 State.Stack.back().FirstLessLess != 0)
507 return State.Stack.back().FirstLessLess;
508 if (NextNonComment->isMemberAccess()) {
509 if (State.Stack.back().CallContinuation == 0) {
510 return ContinuationIndent;
512 return State.Stack.back().CallContinuation;
515 if (State.Stack.back().QuestionColumn != 0 &&
516 ((NextNonComment->is(tok::colon) &&
517 NextNonComment->Type == TT_ConditionalExpr) ||
518 Previous.Type == TT_ConditionalExpr))
519 return State.Stack.back().QuestionColumn;
520 if (Previous.is(tok::comma) && State.Stack.back().VariablePos != 0)
521 return State.Stack.back().VariablePos;
522 if ((PreviousNonComment && (PreviousNonComment->ClosesTemplateDeclaration ||
523 PreviousNonComment->Type == TT_AttributeParen)) ||
524 (!Style.IndentWrappedFunctionNames &&
525 (NextNonComment->is(tok::kw_operator) ||
526 NextNonComment->Type == TT_FunctionDeclarationName)))
527 return std::max(State.Stack.back().LastSpace, State.Stack.back().Indent);
528 if (NextNonComment->Type == TT_SelectorName) {
529 if (!State.Stack.back().ObjCSelectorNameFound) {
530 if (NextNonComment->LongestObjCSelectorName == 0) {
531 return State.Stack.back().Indent;
533 return State.Stack.back().Indent +
534 NextNonComment->LongestObjCSelectorName -
535 NextNonComment->ColumnWidth;
537 } else if (!State.Stack.back().AlignColons) {
538 return State.Stack.back().Indent;
539 } else if (State.Stack.back().ColonPos > NextNonComment->ColumnWidth) {
540 return State.Stack.back().ColonPos - NextNonComment->ColumnWidth;
542 return State.Stack.back().Indent;
545 if (NextNonComment->Type == TT_ArraySubscriptLSquare) {
546 if (State.Stack.back().StartOfArraySubscripts != 0)
547 return State.Stack.back().StartOfArraySubscripts;
549 return ContinuationIndent;
551 if (NextNonComment->Type == TT_StartOfName ||
552 Previous.isOneOf(tok::coloncolon, tok::equal)) {
553 return ContinuationIndent;
555 if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
556 (PreviousNonComment->Type == TT_ObjCMethodExpr ||
557 PreviousNonComment->Type == TT_DictLiteral))
558 return ContinuationIndent;
559 if (NextNonComment->Type == TT_CtorInitializerColon)
560 return State.FirstIndent + Style.ConstructorInitializerIndentWidth;
561 if (NextNonComment->Type == TT_CtorInitializerComma)
562 return State.Stack.back().Indent;
563 if (State.Stack.back().Indent == State.FirstIndent && PreviousNonComment &&
564 PreviousNonComment->isNot(tok::r_brace))
565 // Ensure that we fall back to the continuation indent width instead of
566 // just flushing continuations left.
567 return State.Stack.back().Indent + Style.ContinuationIndentWidth;
568 return State.Stack.back().Indent;
571 unsigned ContinuationIndenter::moveStateToNextToken(LineState &State,
572 bool DryRun, bool Newline) {
573 assert(State.Stack.size());
574 const FormatToken &Current = *State.NextToken;
576 if (Current.Type == TT_InheritanceColon)
577 State.Stack.back().AvoidBinPacking = true;
578 if (Current.is(tok::lessless) && Current.Type != TT_OverloadedOperator) {
579 if (State.Stack.back().FirstLessLess == 0)
580 State.Stack.back().FirstLessLess = State.Column;
582 State.Stack.back().LastOperatorWrapped = Newline;
584 if ((Current.Type == TT_BinaryOperator && Current.isNot(tok::lessless)) ||
585 Current.Type == TT_ConditionalExpr)
586 State.Stack.back().LastOperatorWrapped = Newline;
587 if (Current.Type == TT_ArraySubscriptLSquare &&
588 State.Stack.back().StartOfArraySubscripts == 0)
589 State.Stack.back().StartOfArraySubscripts = State.Column;
590 if ((Current.is(tok::question) && Style.BreakBeforeTernaryOperators) ||
591 (Current.getPreviousNonComment() && Current.isNot(tok::colon) &&
592 Current.getPreviousNonComment()->is(tok::question) &&
593 !Style.BreakBeforeTernaryOperators))
594 State.Stack.back().QuestionColumn = State.Column;
595 if (!Current.opensScope() && !Current.closesScope())
596 State.LowestLevelOnLine =
597 std::min(State.LowestLevelOnLine, Current.NestingLevel);
598 if (Current.isMemberAccess())
599 State.Stack.back().StartOfFunctionCall =
600 Current.LastOperator ? 0 : State.Column + Current.ColumnWidth;
601 if (Current.Type == TT_SelectorName)
602 State.Stack.back().ObjCSelectorNameFound = true;
603 if (Current.Type == TT_CtorInitializerColon) {
604 // Indent 2 from the column, so:
605 // SomeClass::SomeClass()
609 State.Stack.back().Indent =
610 State.Column + (Style.BreakConstructorInitializersBeforeComma ? 0 : 2);
611 if (Style.ConstructorInitializerAllOnOneLineOrOnePerLine)
612 State.Stack.back().AvoidBinPacking = true;
613 State.Stack.back().BreakBeforeParameter = false;
616 // In ObjC method declaration we align on the ":" of parameters, but we need
617 // to ensure that we indent parameters on subsequent lines by at least our
618 // continuation indent width.
619 if (Current.Type == TT_ObjCMethodSpecifier)
620 State.Stack.back().Indent += Style.ContinuationIndentWidth;
622 // Insert scopes created by fake parenthesis.
623 const FormatToken *Previous = Current.getPreviousNonComment();
625 // Add special behavior to support a format commonly used for JavaScript
627 // SomeFunction(function() {
631 if (Style.Language == FormatStyle::LK_JavaScript) {
632 if (Current.isNot(tok::comment) && Previous && Previous->is(tok::l_brace) &&
633 State.Stack.size() > 1) {
634 if (State.Stack[State.Stack.size() - 2].JSFunctionInlined && Newline) {
635 for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i) {
636 State.Stack[i].NoLineBreak = true;
639 State.Stack[State.Stack.size() - 2].JSFunctionInlined = false;
641 if (Current.TokenText == "function")
642 State.Stack.back().JSFunctionInlined = !Newline;
645 moveStatePastFakeLParens(State, Newline);
646 moveStatePastScopeOpener(State, Newline);
647 moveStatePastScopeCloser(State);
648 moveStatePastFakeRParens(State);
650 if (Current.isStringLiteral() && State.StartOfStringLiteral == 0) {
651 State.StartOfStringLiteral = State.Column;
652 } else if (!Current.isOneOf(tok::comment, tok::identifier, tok::hash) &&
653 !Current.isStringLiteral()) {
654 State.StartOfStringLiteral = 0;
657 State.Column += Current.ColumnWidth;
658 State.NextToken = State.NextToken->Next;
659 unsigned Penalty = breakProtrudingToken(Current, State, DryRun);
660 if (State.Column > getColumnLimit(State)) {
661 unsigned ExcessCharacters = State.Column - getColumnLimit(State);
662 Penalty += Style.PenaltyExcessCharacter * ExcessCharacters;
666 Current.Role->formatFromToken(State, this, DryRun);
667 // If the previous has a special role, let it consume tokens as appropriate.
668 // It is necessary to start at the previous token for the only implemented
669 // role (comma separated list). That way, the decision whether or not to break
670 // after the "{" is already done and both options are tried and evaluated.
671 // FIXME: This is ugly, find a better way.
672 if (Previous && Previous->Role)
673 Penalty += Previous->Role->formatAfterToken(State, this, DryRun);
678 void ContinuationIndenter::moveStatePastFakeLParens(LineState &State,
680 const FormatToken &Current = *State.NextToken;
681 const FormatToken *Previous = Current.getPreviousNonComment();
683 // Don't add extra indentation for the first fake parenthesis after
684 // 'return', assignments or opening <({[. The indentation for these cases
686 bool SkipFirstExtraIndent =
687 (Previous && (Previous->opensScope() || Previous->is(tok::kw_return) ||
688 Previous->getPrecedence() == prec::Assignment ||
689 Previous->Type == TT_ObjCMethodExpr));
690 for (SmallVectorImpl<prec::Level>::const_reverse_iterator
691 I = Current.FakeLParens.rbegin(),
692 E = Current.FakeLParens.rend();
694 ParenState NewParenState = State.Stack.back();
695 NewParenState.ContainsLineBreak = false;
697 // Indent from 'LastSpace' unless this the fake parentheses encapsulating a
698 // builder type call after 'return'. If such a call is line-wrapped, we
699 // commonly just want to indent from the start of the line.
700 if (!Previous || Previous->isNot(tok::kw_return) || *I > 0)
701 NewParenState.Indent =
702 std::max(std::max(State.Column, NewParenState.Indent),
703 State.Stack.back().LastSpace);
705 // Don't allow the RHS of an operator to be split over multiple lines unless
706 // there is a line-break right after the operator.
707 // Exclude relational operators, as there, it is always more desirable to
708 // have the LHS 'left' of the RHS.
709 if (Previous && Previous->getPrecedence() > prec::Assignment &&
710 (Previous->Type == TT_BinaryOperator ||
711 Previous->Type == TT_ConditionalExpr) &&
712 Previous->getPrecedence() != prec::Relational) {
713 bool BreakBeforeOperator = Previous->is(tok::lessless) ||
714 (Previous->Type == TT_BinaryOperator &&
715 Style.BreakBeforeBinaryOperators) ||
716 (Previous->Type == TT_ConditionalExpr &&
717 Style.BreakBeforeTernaryOperators);
718 if ((!Newline && !BreakBeforeOperator) ||
719 (!State.Stack.back().LastOperatorWrapped && BreakBeforeOperator))
720 NewParenState.NoLineBreak = true;
723 // Do not indent relative to the fake parentheses inserted for "." or "->".
724 // This is a special case to make the following to statements consistent:
725 // OuterFunction(InnerFunctionCall( // break
726 // ParameterToInnerFunction));
727 // OuterFunction(SomeObject.InnerFunctionCall( // break
728 // ParameterToInnerFunction));
729 if (*I > prec::Unknown)
730 NewParenState.LastSpace = std::max(NewParenState.LastSpace, State.Column);
731 NewParenState.StartOfFunctionCall = State.Column;
733 // Always indent conditional expressions. Never indent expression where
734 // the 'operator' is ',', ';' or an assignment (i.e. *I <=
735 // prec::Assignment) as those have different indentation rules. Indent
736 // other expression, unless the indentation needs to be skipped.
737 if (*I == prec::Conditional ||
738 (!SkipFirstExtraIndent && *I > prec::Assignment &&
739 !Style.BreakBeforeBinaryOperators))
740 NewParenState.Indent += Style.ContinuationIndentWidth;
741 if ((Previous && !Previous->opensScope()) || *I > prec::Comma)
742 NewParenState.BreakBeforeParameter = false;
743 State.Stack.push_back(NewParenState);
744 SkipFirstExtraIndent = false;
748 // Remove the fake r_parens after 'Tok'.
749 static void consumeRParens(LineState& State, const FormatToken &Tok) {
750 for (unsigned i = 0, e = Tok.FakeRParens; i != e; ++i) {
751 unsigned VariablePos = State.Stack.back().VariablePos;
752 assert(State.Stack.size() > 1);
753 if (State.Stack.size() == 1) {
754 // Do not pop the last element.
757 State.Stack.pop_back();
758 State.Stack.back().VariablePos = VariablePos;
762 // Returns whether 'Tok' opens or closes a scope requiring special handling
763 // of the subsequent fake r_parens.
765 // For example, if this is an l_brace starting a nested block, we pretend (wrt.
766 // to indentation) that we already consumed the corresponding r_brace. Thus, we
767 // remove all ParenStates caused by fake parentheses that end at the r_brace.
768 // The net effect of this is that we don't indent relative to the l_brace, if
769 // the nested block is the last parameter of a function. This formats:
771 // SomeFunction(a, [] {
776 // SomeFunction(a, [] {
779 static bool fakeRParenSpecialCase(const LineState &State) {
780 const FormatToken &Tok = *State.NextToken;
781 if (!Tok.MatchingParen)
783 const FormatToken *Left = &Tok;
784 if (Tok.isOneOf(tok::r_brace, tok::r_square))
785 Left = Tok.MatchingParen;
786 return !State.Stack.back().HasMultipleNestedBlocks &&
787 Left->isOneOf(tok::l_brace, tok::l_square) &&
788 (Left->BlockKind == BK_Block ||
789 Left->Type == TT_ArrayInitializerLSquare ||
790 Left->Type == TT_DictLiteral);
793 void ContinuationIndenter::moveStatePastFakeRParens(LineState &State) {
794 // Don't remove FakeRParens attached to r_braces that surround nested blocks
795 // as they will have been removed early (see above).
796 if (fakeRParenSpecialCase(State))
799 consumeRParens(State, *State.NextToken);
802 void ContinuationIndenter::moveStatePastScopeOpener(LineState &State,
804 const FormatToken &Current = *State.NextToken;
805 if (!Current.opensScope())
808 if (Current.MatchingParen && Current.BlockKind == BK_Block) {
809 moveStateToNewBlock(State);
814 unsigned NewIndentLevel = State.Stack.back().IndentLevel;
815 bool AvoidBinPacking;
816 bool BreakBeforeParameter = false;
817 if (Current.is(tok::l_brace) || Current.Type == TT_ArrayInitializerLSquare) {
818 if (fakeRParenSpecialCase(State))
819 consumeRParens(State, *Current.MatchingParen);
821 NewIndent = State.Stack.back().LastSpace;
822 if (Current.opensBlockTypeList(Style)) {
823 NewIndent += Style.IndentWidth;
824 NewIndent = std::min(State.Column + 2, NewIndent);
827 NewIndent += Style.ContinuationIndentWidth;
828 NewIndent = std::min(State.Column + 1, NewIndent);
830 const FormatToken *NextNoComment = Current.getNextNonComment();
831 AvoidBinPacking = Current.Type == TT_ArrayInitializerLSquare ||
832 Current.Type == TT_DictLiteral ||
833 Style.Language == FormatStyle::LK_Proto ||
834 !Style.BinPackParameters ||
836 NextNoComment->Type == TT_DesignatedInitializerPeriod);
838 NewIndent = Style.ContinuationIndentWidth +
839 std::max(State.Stack.back().LastSpace,
840 State.Stack.back().StartOfFunctionCall);
841 AvoidBinPacking = !Style.BinPackParameters ||
842 (Style.ExperimentalAutoDetectBinPacking &&
843 (Current.PackingKind == PPK_OnePerLine ||
844 (!BinPackInconclusiveFunctions &&
845 Current.PackingKind == PPK_Inconclusive)));
846 // If this '[' opens an ObjC call, determine whether all parameters fit
847 // into one line and put one per line if they don't.
848 if (Current.Type == TT_ObjCMethodExpr && Style.ColumnLimit != 0 &&
849 getLengthToMatchingParen(Current) + State.Column >
850 getColumnLimit(State))
851 BreakBeforeParameter = true;
853 bool NoLineBreak = State.Stack.back().NoLineBreak ||
854 (Current.Type == TT_TemplateOpener &&
855 State.Stack.back().ContainsUnwrappedBuilder);
856 State.Stack.push_back(ParenState(NewIndent, NewIndentLevel,
857 State.Stack.back().LastSpace,
858 AvoidBinPacking, NoLineBreak));
859 State.Stack.back().BreakBeforeParameter = BreakBeforeParameter;
860 State.Stack.back().HasMultipleNestedBlocks = Current.BlockParameterCount > 1;
863 void ContinuationIndenter::moveStatePastScopeCloser(LineState &State) {
864 const FormatToken &Current = *State.NextToken;
865 if (!Current.closesScope())
868 // If we encounter a closing ), ], } or >, we can remove a level from our
870 if (State.Stack.size() > 1 &&
871 (Current.isOneOf(tok::r_paren, tok::r_square) ||
872 (Current.is(tok::r_brace) && State.NextToken != State.Line->First) ||
873 State.NextToken->Type == TT_TemplateCloser))
874 State.Stack.pop_back();
876 if (Current.is(tok::r_square)) {
877 // If this ends the array subscript expr, reset the corresponding value.
878 const FormatToken *NextNonComment = Current.getNextNonComment();
879 if (NextNonComment && NextNonComment->isNot(tok::l_square))
880 State.Stack.back().StartOfArraySubscripts = 0;
884 void ContinuationIndenter::moveStateToNewBlock(LineState &State) {
885 // If we have already found more than one lambda introducers on this level, we
886 // opt out of this because similarity between the lambdas is more important.
887 if (fakeRParenSpecialCase(State))
888 consumeRParens(State, *State.NextToken->MatchingParen);
890 // For some reason, ObjC blocks are indented like continuations.
891 unsigned NewIndent = State.Stack.back().LastSpace +
892 (State.NextToken->Type == TT_ObjCBlockLBrace
893 ? Style.ContinuationIndentWidth
894 : Style.IndentWidth);
895 State.Stack.push_back(ParenState(
896 NewIndent, /*NewIndentLevel=*/State.Stack.back().IndentLevel + 1,
897 State.Stack.back().LastSpace, /*AvoidBinPacking=*/true,
898 State.Stack.back().NoLineBreak));
899 State.Stack.back().BreakBeforeParameter = true;
902 unsigned ContinuationIndenter::addMultilineToken(const FormatToken &Current,
904 // Break before further function parameters on all levels.
905 for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
906 State.Stack[i].BreakBeforeParameter = true;
908 unsigned ColumnsUsed = State.Column;
909 // We can only affect layout of the first and the last line, so the penalty
910 // for all other lines is constant, and we ignore it.
911 State.Column = Current.LastLineColumnWidth;
913 if (ColumnsUsed > getColumnLimit(State))
914 return Style.PenaltyExcessCharacter * (ColumnsUsed - getColumnLimit(State));
918 static bool getRawStringLiteralPrefixPostfix(StringRef Text, StringRef &Prefix,
919 StringRef &Postfix) {
920 if (Text.startswith(Prefix = "R\"") || Text.startswith(Prefix = "uR\"") ||
921 Text.startswith(Prefix = "UR\"") || Text.startswith(Prefix = "u8R\"") ||
922 Text.startswith(Prefix = "LR\"")) {
923 size_t ParenPos = Text.find('(');
924 if (ParenPos != StringRef::npos) {
925 StringRef Delimiter =
926 Text.substr(Prefix.size(), ParenPos - Prefix.size());
927 Prefix = Text.substr(0, ParenPos + 1);
928 Postfix = Text.substr(Text.size() - 2 - Delimiter.size());
929 return Postfix.front() == ')' && Postfix.back() == '"' &&
930 Postfix.substr(1).startswith(Delimiter);
936 unsigned ContinuationIndenter::breakProtrudingToken(const FormatToken &Current,
939 // Don't break multi-line tokens other than block comments. Instead, just
941 if (Current.Type != TT_BlockComment && Current.IsMultiline)
942 return addMultilineToken(Current, State);
944 // Don't break implicit string literals.
945 if (Current.Type == TT_ImplicitStringLiteral)
948 if (!Current.isStringLiteral() && !Current.is(tok::comment))
951 std::unique_ptr<BreakableToken> Token;
952 unsigned StartColumn = State.Column - Current.ColumnWidth;
953 unsigned ColumnLimit = getColumnLimit(State);
955 if (Current.isStringLiteral()) {
956 // Don't break string literals inside preprocessor directives (except for
957 // #define directives, as their contents are stored in separate lines and
958 // are not affected by this check).
959 // This way we avoid breaking code with line directives and unknown
960 // preprocessor directives that contain long string literals.
961 if (State.Line->Type == LT_PreprocessorDirective)
963 // Exempts unterminated string literals from line breaking. The user will
964 // likely want to terminate the string before any line breaking is done.
965 if (Current.IsUnterminatedLiteral)
968 StringRef Text = Current.TokenText;
971 bool IsNSStringLiteral = false;
972 // FIXME: Handle whitespace between '_T', '(', '"..."', and ')'.
973 // FIXME: Store Prefix and Suffix (or PrefixLength and SuffixLength to
974 // reduce the overhead) for each FormatToken, which is a string, so that we
975 // don't run multiple checks here on the hot path.
976 if (Text.startswith("\"") && Current.Previous &&
977 Current.Previous->is(tok::at)) {
978 IsNSStringLiteral = true;
981 if ((Text.endswith(Postfix = "\"") &&
982 (IsNSStringLiteral || Text.startswith(Prefix = "\"") ||
983 Text.startswith(Prefix = "u\"") || Text.startswith(Prefix = "U\"") ||
984 Text.startswith(Prefix = "u8\"") ||
985 Text.startswith(Prefix = "L\""))) ||
986 (Text.startswith(Prefix = "_T(\"") && Text.endswith(Postfix = "\")")) ||
987 getRawStringLiteralPrefixPostfix(Text, Prefix, Postfix)) {
988 Token.reset(new BreakableStringLiteral(
989 Current, State.Line->Level, StartColumn, Prefix, Postfix,
990 State.Line->InPPDirective, Encoding, Style));
994 } else if (Current.Type == TT_BlockComment && Current.isTrailingComment()) {
995 if (CommentPragmasRegex.match(Current.TokenText.substr(2)))
997 Token.reset(new BreakableBlockComment(
998 Current, State.Line->Level, StartColumn, Current.OriginalColumn,
999 !Current.Previous, State.Line->InPPDirective, Encoding, Style));
1000 } else if (Current.Type == TT_LineComment &&
1001 (Current.Previous == nullptr ||
1002 Current.Previous->Type != TT_ImplicitStringLiteral)) {
1003 if (CommentPragmasRegex.match(Current.TokenText.substr(2)))
1005 Token.reset(new BreakableLineComment(Current, State.Line->Level,
1006 StartColumn, /*InPPDirective=*/false,
1008 // We don't insert backslashes when breaking line comments.
1009 ColumnLimit = Style.ColumnLimit;
1013 if (Current.UnbreakableTailLength >= ColumnLimit)
1016 unsigned RemainingSpace = ColumnLimit - Current.UnbreakableTailLength;
1017 bool BreakInserted = false;
1018 unsigned Penalty = 0;
1019 unsigned RemainingTokenColumns = 0;
1020 for (unsigned LineIndex = 0, EndIndex = Token->getLineCount();
1021 LineIndex != EndIndex; ++LineIndex) {
1023 Token->replaceWhitespaceBefore(LineIndex, Whitespaces);
1024 unsigned TailOffset = 0;
1025 RemainingTokenColumns =
1026 Token->getLineLengthAfterSplit(LineIndex, TailOffset, StringRef::npos);
1027 while (RemainingTokenColumns > RemainingSpace) {
1028 BreakableToken::Split Split =
1029 Token->getSplit(LineIndex, TailOffset, ColumnLimit);
1030 if (Split.first == StringRef::npos) {
1031 // The last line's penalty is handled in addNextStateToQueue().
1032 if (LineIndex < EndIndex - 1)
1033 Penalty += Style.PenaltyExcessCharacter *
1034 (RemainingTokenColumns - RemainingSpace);
1037 assert(Split.first != 0);
1038 unsigned NewRemainingTokenColumns = Token->getLineLengthAfterSplit(
1039 LineIndex, TailOffset + Split.first + Split.second, StringRef::npos);
1041 // We can remove extra whitespace instead of breaking the line.
1042 if (RemainingTokenColumns + 1 - Split.second <= RemainingSpace) {
1043 RemainingTokenColumns = 0;
1045 Token->replaceWhitespace(LineIndex, TailOffset, Split, Whitespaces);
1049 // When breaking before a tab character, it may be moved by a few columns,
1050 // but will still be expanded to the next tab stop, so we don't save any
1052 if (NewRemainingTokenColumns == RemainingTokenColumns)
1055 assert(NewRemainingTokenColumns < RemainingTokenColumns);
1057 Token->insertBreak(LineIndex, TailOffset, Split, Whitespaces);
1058 Penalty += Current.SplitPenalty;
1059 unsigned ColumnsUsed =
1060 Token->getLineLengthAfterSplit(LineIndex, TailOffset, Split.first);
1061 if (ColumnsUsed > ColumnLimit) {
1062 Penalty += Style.PenaltyExcessCharacter * (ColumnsUsed - ColumnLimit);
1064 TailOffset += Split.first + Split.second;
1065 RemainingTokenColumns = NewRemainingTokenColumns;
1066 BreakInserted = true;
1070 State.Column = RemainingTokenColumns;
1072 if (BreakInserted) {
1073 // If we break the token inside a parameter list, we need to break before
1074 // the next parameter on all levels, so that the next parameter is clearly
1075 // visible. Line comments already introduce a break.
1076 if (Current.Type != TT_LineComment) {
1077 for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
1078 State.Stack[i].BreakBeforeParameter = true;
1081 Penalty += Current.isStringLiteral() ? Style.PenaltyBreakString
1082 : Style.PenaltyBreakComment;
1084 State.Stack.back().LastSpace = StartColumn;
1089 unsigned ContinuationIndenter::getColumnLimit(const LineState &State) const {
1090 // In preprocessor directives reserve two chars for trailing " \"
1091 return Style.ColumnLimit - (State.Line->InPPDirective ? 2 : 0);
1094 bool ContinuationIndenter::nextIsMultilineString(const LineState &State) {
1095 const FormatToken &Current = *State.NextToken;
1096 if (!Current.isStringLiteral() || Current.Type == TT_ImplicitStringLiteral)
1098 // We never consider raw string literals "multiline" for the purpose of
1099 // AlwaysBreakBeforeMultilineStrings implementation as they are special-cased
1100 // (see TokenAnnotator::mustBreakBefore().
1101 if (Current.TokenText.startswith("R\""))
1103 if (Current.IsMultiline)
1105 if (Current.getNextNonComment() &&
1106 Current.getNextNonComment()->isStringLiteral())
1107 return true; // Implicit concatenation.
1108 if (State.Column + Current.ColumnWidth + Current.UnbreakableTailLength >
1110 return true; // String will be split.
1114 } // namespace format
1115 } // namespace clang