xref: /llvm-project/clang/lib/Format/ContinuationIndenter.cpp (revision e2402615a5a76d46a433dfcc1de10b38a1263c9d)
1 //===--- ContinuationIndenter.cpp - Format C++ code -----------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 ///
9 /// \file
10 /// This file implements the continuation indenter.
11 ///
12 //===----------------------------------------------------------------------===//
13 
14 #include "ContinuationIndenter.h"
15 #include "BreakableToken.h"
16 #include "FormatInternal.h"
17 #include "FormatToken.h"
18 #include "WhitespaceManager.h"
19 #include "clang/Basic/OperatorPrecedence.h"
20 #include "clang/Basic/SourceManager.h"
21 #include "clang/Basic/TokenKinds.h"
22 #include "clang/Format/Format.h"
23 #include "llvm/ADT/StringSet.h"
24 #include "llvm/Support/Debug.h"
25 #include <optional>
26 
27 #define DEBUG_TYPE "format-indenter"
28 
29 namespace clang {
30 namespace format {
31 
32 // Returns true if a TT_SelectorName should be indented when wrapped,
33 // false otherwise.
34 static bool shouldIndentWrappedSelectorName(const FormatStyle &Style,
35                                             LineType LineType) {
36   return Style.IndentWrappedFunctionNames || LineType == LT_ObjCMethodDecl;
37 }
38 
39 // Returns true if a binary operator following \p Tok should be unindented when
40 // the style permits it.
41 static bool shouldUnindentNextOperator(const FormatToken &Tok) {
42   const FormatToken *Previous = Tok.getPreviousNonComment();
43   return Previous && (Previous->getPrecedence() == prec::Assignment ||
44                       Previous->isOneOf(tok::kw_return, TT_RequiresClause));
45 }
46 
47 // Returns the length of everything up to the first possible line break after
48 // the ), ], } or > matching \c Tok.
49 static unsigned getLengthToMatchingParen(const FormatToken &Tok,
50                                          ArrayRef<ParenState> Stack) {
51   // Normally whether or not a break before T is possible is calculated and
52   // stored in T.CanBreakBefore. Braces, array initializers and text proto
53   // messages like `key: < ... >` are an exception: a break is possible
54   // before a closing brace R if a break was inserted after the corresponding
55   // opening brace. The information about whether or not a break is needed
56   // before a closing brace R is stored in the ParenState field
57   // S.BreakBeforeClosingBrace where S is the state that R closes.
58   //
59   // In order to decide whether there can be a break before encountered right
60   // braces, this implementation iterates over the sequence of tokens and over
61   // the paren stack in lockstep, keeping track of the stack level which visited
62   // right braces correspond to in MatchingStackIndex.
63   //
64   // For example, consider:
65   // L. <- line number
66   // 1. {
67   // 2. {1},
68   // 3. {2},
69   // 4. {{3}}}
70   //     ^ where we call this method with this token.
71   // The paren stack at this point contains 3 brace levels:
72   //  0. { at line 1, BreakBeforeClosingBrace: true
73   //  1. first { at line 4, BreakBeforeClosingBrace: false
74   //  2. second { at line 4, BreakBeforeClosingBrace: false,
75   //  where there might be fake parens levels in-between these levels.
76   // The algorithm will start at the first } on line 4, which is the matching
77   // brace of the initial left brace and at level 2 of the stack. Then,
78   // examining BreakBeforeClosingBrace: false at level 2, it will continue to
79   // the second } on line 4, and will traverse the stack downwards until it
80   // finds the matching { on level 1. Then, examining BreakBeforeClosingBrace:
81   // false at level 1, it will continue to the third } on line 4 and will
82   // traverse the stack downwards until it finds the matching { on level 0.
83   // Then, examining BreakBeforeClosingBrace: true at level 0, the algorithm
84   // will stop and will use the second } on line 4 to determine the length to
85   // return, as in this example the range will include the tokens: {3}}
86   //
87   // The algorithm will only traverse the stack if it encounters braces, array
88   // initializer squares or text proto angle brackets.
89   if (!Tok.MatchingParen)
90     return 0;
91   FormatToken *End = Tok.MatchingParen;
92   // Maintains a stack level corresponding to the current End token.
93   int MatchingStackIndex = Stack.size() - 1;
94   // Traverses the stack downwards, looking for the level to which LBrace
95   // corresponds. Returns either a pointer to the matching level or nullptr if
96   // LParen is not found in the initial portion of the stack up to
97   // MatchingStackIndex.
98   auto FindParenState = [&](const FormatToken *LBrace) -> const ParenState * {
99     while (MatchingStackIndex >= 0 && Stack[MatchingStackIndex].Tok != LBrace)
100       --MatchingStackIndex;
101     return MatchingStackIndex >= 0 ? &Stack[MatchingStackIndex] : nullptr;
102   };
103   for (; End->Next; End = End->Next) {
104     if (End->Next->CanBreakBefore)
105       break;
106     if (!End->Next->closesScope())
107       continue;
108     if (End->Next->MatchingParen &&
109         End->Next->MatchingParen->isOneOf(
110             tok::l_brace, TT_ArrayInitializerLSquare, tok::less)) {
111       const ParenState *State = FindParenState(End->Next->MatchingParen);
112       if (State && State->BreakBeforeClosingBrace)
113         break;
114     }
115   }
116   return End->TotalLength - Tok.TotalLength + 1;
117 }
118 
119 static unsigned getLengthToNextOperator(const FormatToken &Tok) {
120   if (!Tok.NextOperator)
121     return 0;
122   return Tok.NextOperator->TotalLength - Tok.TotalLength;
123 }
124 
125 // Returns \c true if \c Tok is the "." or "->" of a call and starts the next
126 // segment of a builder type call.
127 static bool startsSegmentOfBuilderTypeCall(const FormatToken &Tok) {
128   return Tok.isMemberAccess() && Tok.Previous && Tok.Previous->closesScope();
129 }
130 
131 // Returns \c true if \c Token in an alignable binary operator
132 static bool isAlignableBinaryOperator(const FormatToken &Token) {
133   // No need to align binary operators that only have two operands.
134   bool HasTwoOperands = Token.OperatorIndex == 0 && !Token.NextOperator;
135   return Token.is(TT_BinaryOperator) && !HasTwoOperands &&
136          Token.getPrecedence() > prec::Conditional &&
137          Token.getPrecedence() < prec::PointerToMember;
138 }
139 
140 // Returns \c true if \c Current starts the next operand in a binary operation.
141 static bool startsNextOperand(const FormatToken &Current) {
142   assert(Current.Previous);
143   const auto &Previous = *Current.Previous;
144   return isAlignableBinaryOperator(Previous) && !Current.isTrailingComment();
145 }
146 
147 // Returns \c true if \c Current is a binary operation that must break.
148 static bool mustBreakBinaryOperation(const FormatToken &Current,
149                                      const FormatStyle &Style) {
150   return Style.BreakBinaryOperations != FormatStyle::BBO_Never &&
151          Current.CanBreakBefore &&
152          (Style.BreakBeforeBinaryOperators == FormatStyle::BOS_None
153               ? startsNextOperand
154               : isAlignableBinaryOperator)(Current);
155 }
156 
157 static bool opensProtoMessageField(const FormatToken &LessTok,
158                                    const FormatStyle &Style) {
159   if (LessTok.isNot(tok::less))
160     return false;
161   return Style.Language == FormatStyle::LK_TextProto ||
162          (Style.Language == FormatStyle::LK_Proto &&
163           (LessTok.NestingLevel > 0 ||
164            (LessTok.Previous && LessTok.Previous->is(tok::equal))));
165 }
166 
167 // Returns the delimiter of a raw string literal, or std::nullopt if TokenText
168 // is not the text of a raw string literal. The delimiter could be the empty
169 // string.  For example, the delimiter of R"deli(cont)deli" is deli.
170 static std::optional<StringRef> getRawStringDelimiter(StringRef TokenText) {
171   if (TokenText.size() < 5 // The smallest raw string possible is 'R"()"'.
172       || !TokenText.starts_with("R\"") || !TokenText.ends_with("\"")) {
173     return std::nullopt;
174   }
175 
176   // A raw string starts with 'R"<delimiter>(' and delimiter is ascii and has
177   // size at most 16 by the standard, so the first '(' must be among the first
178   // 19 bytes.
179   size_t LParenPos = TokenText.substr(0, 19).find_first_of('(');
180   if (LParenPos == StringRef::npos)
181     return std::nullopt;
182   StringRef Delimiter = TokenText.substr(2, LParenPos - 2);
183 
184   // Check that the string ends in ')Delimiter"'.
185   size_t RParenPos = TokenText.size() - Delimiter.size() - 2;
186   if (TokenText[RParenPos] != ')')
187     return std::nullopt;
188   if (!TokenText.substr(RParenPos + 1).starts_with(Delimiter))
189     return std::nullopt;
190   return Delimiter;
191 }
192 
193 // Returns the canonical delimiter for \p Language, or the empty string if no
194 // canonical delimiter is specified.
195 static StringRef
196 getCanonicalRawStringDelimiter(const FormatStyle &Style,
197                                FormatStyle::LanguageKind Language) {
198   for (const auto &Format : Style.RawStringFormats)
199     if (Format.Language == Language)
200       return StringRef(Format.CanonicalDelimiter);
201   return "";
202 }
203 
204 RawStringFormatStyleManager::RawStringFormatStyleManager(
205     const FormatStyle &CodeStyle) {
206   for (const auto &RawStringFormat : CodeStyle.RawStringFormats) {
207     std::optional<FormatStyle> LanguageStyle =
208         CodeStyle.GetLanguageStyle(RawStringFormat.Language);
209     if (!LanguageStyle) {
210       FormatStyle PredefinedStyle;
211       if (!getPredefinedStyle(RawStringFormat.BasedOnStyle,
212                               RawStringFormat.Language, &PredefinedStyle)) {
213         PredefinedStyle = getLLVMStyle();
214         PredefinedStyle.Language = RawStringFormat.Language;
215       }
216       LanguageStyle = PredefinedStyle;
217     }
218     LanguageStyle->ColumnLimit = CodeStyle.ColumnLimit;
219     for (StringRef Delimiter : RawStringFormat.Delimiters)
220       DelimiterStyle.insert({Delimiter, *LanguageStyle});
221     for (StringRef EnclosingFunction : RawStringFormat.EnclosingFunctions)
222       EnclosingFunctionStyle.insert({EnclosingFunction, *LanguageStyle});
223   }
224 }
225 
226 std::optional<FormatStyle>
227 RawStringFormatStyleManager::getDelimiterStyle(StringRef Delimiter) const {
228   auto It = DelimiterStyle.find(Delimiter);
229   if (It == DelimiterStyle.end())
230     return std::nullopt;
231   return It->second;
232 }
233 
234 std::optional<FormatStyle>
235 RawStringFormatStyleManager::getEnclosingFunctionStyle(
236     StringRef EnclosingFunction) const {
237   auto It = EnclosingFunctionStyle.find(EnclosingFunction);
238   if (It == EnclosingFunctionStyle.end())
239     return std::nullopt;
240   return It->second;
241 }
242 
243 ContinuationIndenter::ContinuationIndenter(const FormatStyle &Style,
244                                            const AdditionalKeywords &Keywords,
245                                            const SourceManager &SourceMgr,
246                                            WhitespaceManager &Whitespaces,
247                                            encoding::Encoding Encoding,
248                                            bool BinPackInconclusiveFunctions)
249     : Style(Style), Keywords(Keywords), SourceMgr(SourceMgr),
250       Whitespaces(Whitespaces), Encoding(Encoding),
251       BinPackInconclusiveFunctions(BinPackInconclusiveFunctions),
252       CommentPragmasRegex(Style.CommentPragmas), RawStringFormats(Style) {}
253 
254 LineState ContinuationIndenter::getInitialState(unsigned FirstIndent,
255                                                 unsigned FirstStartColumn,
256                                                 const AnnotatedLine *Line,
257                                                 bool DryRun) {
258   LineState State;
259   State.FirstIndent = FirstIndent;
260   if (FirstStartColumn && Line->First->NewlinesBefore == 0)
261     State.Column = FirstStartColumn;
262   else
263     State.Column = FirstIndent;
264   // With preprocessor directive indentation, the line starts on column 0
265   // since it's indented after the hash, but FirstIndent is set to the
266   // preprocessor indent.
267   if (Style.IndentPPDirectives == FormatStyle::PPDIS_AfterHash &&
268       (Line->Type == LT_PreprocessorDirective ||
269        Line->Type == LT_ImportStatement)) {
270     State.Column = 0;
271   }
272   State.Line = Line;
273   State.NextToken = Line->First;
274   State.Stack.push_back(ParenState(/*Tok=*/nullptr, FirstIndent, FirstIndent,
275                                    /*AvoidBinPacking=*/false,
276                                    /*NoLineBreak=*/false));
277   State.NoContinuation = false;
278   State.StartOfStringLiteral = 0;
279   State.NoLineBreak = false;
280   State.StartOfLineLevel = 0;
281   State.LowestLevelOnLine = 0;
282   State.IgnoreStackForComparison = false;
283 
284   if (Style.Language == FormatStyle::LK_TextProto) {
285     // We need this in order to deal with the bin packing of text fields at
286     // global scope.
287     auto &CurrentState = State.Stack.back();
288     CurrentState.AvoidBinPacking = true;
289     CurrentState.BreakBeforeParameter = true;
290     CurrentState.AlignColons = false;
291   }
292 
293   // The first token has already been indented and thus consumed.
294   moveStateToNextToken(State, DryRun, /*Newline=*/false);
295   return State;
296 }
297 
298 bool ContinuationIndenter::canBreak(const LineState &State) {
299   const FormatToken &Current = *State.NextToken;
300   const FormatToken &Previous = *Current.Previous;
301   const auto &CurrentState = State.Stack.back();
302   assert(&Previous == Current.Previous);
303   if (!Current.CanBreakBefore && !(CurrentState.BreakBeforeClosingBrace &&
304                                    Current.closesBlockOrBlockTypeList(Style))) {
305     return false;
306   }
307   // The opening "{" of a braced list has to be on the same line as the first
308   // element if it is nested in another braced init list or function call.
309   if (!Current.MustBreakBefore && Previous.is(tok::l_brace) &&
310       Previous.isNot(TT_DictLiteral) && Previous.is(BK_BracedInit) &&
311       Previous.Previous &&
312       Previous.Previous->isOneOf(tok::l_brace, tok::l_paren, tok::comma)) {
313     return false;
314   }
315   // This prevents breaks like:
316   //   ...
317   //   SomeParameter, OtherParameter).DoSomething(
318   //   ...
319   // As they hide "DoSomething" and are generally bad for readability.
320   if (Previous.opensScope() && Previous.isNot(tok::l_brace) &&
321       State.LowestLevelOnLine < State.StartOfLineLevel &&
322       State.LowestLevelOnLine < Current.NestingLevel) {
323     return false;
324   }
325   if (Current.isMemberAccess() && CurrentState.ContainsUnwrappedBuilder)
326     return false;
327 
328   // Don't create a 'hanging' indent if there are multiple blocks in a single
329   // statement and we are aligning lambda blocks to their signatures.
330   if (Previous.is(tok::l_brace) && State.Stack.size() > 1 &&
331       State.Stack[State.Stack.size() - 2].NestedBlockInlined &&
332       State.Stack[State.Stack.size() - 2].HasMultipleNestedBlocks &&
333       Style.LambdaBodyIndentation == FormatStyle::LBI_Signature) {
334     return false;
335   }
336 
337   // Don't break after very short return types (e.g. "void") as that is often
338   // unexpected.
339   if (Current.is(TT_FunctionDeclarationName)) {
340     if (Style.BreakAfterReturnType == FormatStyle::RTBS_None &&
341         State.Column < 6) {
342       return false;
343     }
344 
345     if (Style.BreakAfterReturnType == FormatStyle::RTBS_ExceptShortType) {
346       assert(State.Column >= State.FirstIndent);
347       if (State.Column - State.FirstIndent < 6)
348         return false;
349     }
350   }
351 
352   // Don't allow breaking before a closing brace of a block-indented braced list
353   // initializer if there isn't already a break.
354   if (Current.is(tok::r_brace) && Current.MatchingParen &&
355       Current.isBlockIndentedInitRBrace(Style)) {
356     return CurrentState.BreakBeforeClosingBrace;
357   }
358 
359   // If binary operators are moved to the next line (including commas for some
360   // styles of constructor initializers), that's always ok.
361   if (!Current.isOneOf(TT_BinaryOperator, tok::comma) &&
362       // Allow breaking opening brace of lambdas (when passed as function
363       // arguments) to a new line when BeforeLambdaBody brace wrapping is
364       // enabled.
365       (!Style.BraceWrapping.BeforeLambdaBody ||
366        Current.isNot(TT_LambdaLBrace)) &&
367       CurrentState.NoLineBreakInOperand) {
368     return false;
369   }
370 
371   if (Previous.is(tok::l_square) && Previous.is(TT_ObjCMethodExpr))
372     return false;
373 
374   if (Current.is(TT_ConditionalExpr) && Previous.is(tok::r_paren) &&
375       Previous.MatchingParen && Previous.MatchingParen->Previous &&
376       Previous.MatchingParen->Previous->MatchingParen &&
377       Previous.MatchingParen->Previous->MatchingParen->is(TT_LambdaLBrace)) {
378     // We have a lambda within a conditional expression, allow breaking here.
379     assert(Previous.MatchingParen->Previous->is(tok::r_brace));
380     return true;
381   }
382 
383   return !State.NoLineBreak && !CurrentState.NoLineBreak;
384 }
385 
386 bool ContinuationIndenter::mustBreak(const LineState &State) {
387   const FormatToken &Current = *State.NextToken;
388   const FormatToken &Previous = *Current.Previous;
389   const auto &CurrentState = State.Stack.back();
390   if (Style.BraceWrapping.BeforeLambdaBody && Current.CanBreakBefore &&
391       Current.is(TT_LambdaLBrace) && Previous.isNot(TT_LineComment)) {
392     auto LambdaBodyLength = getLengthToMatchingParen(Current, State.Stack);
393     return LambdaBodyLength > getColumnLimit(State);
394   }
395   if (Current.MustBreakBefore ||
396       (Current.is(TT_InlineASMColon) &&
397        (Style.BreakBeforeInlineASMColon == FormatStyle::BBIAS_Always ||
398         (Style.BreakBeforeInlineASMColon == FormatStyle::BBIAS_OnlyMultiline &&
399          Style.ColumnLimit > 0)))) {
400     return true;
401   }
402   if (CurrentState.BreakBeforeClosingBrace &&
403       (Current.closesBlockOrBlockTypeList(Style) ||
404        (Current.is(tok::r_brace) &&
405         Current.isBlockIndentedInitRBrace(Style)))) {
406     return true;
407   }
408   if (CurrentState.BreakBeforeClosingParen && Current.is(tok::r_paren))
409     return true;
410   if (Style.Language == FormatStyle::LK_ObjC &&
411       Style.ObjCBreakBeforeNestedBlockParam &&
412       Current.ObjCSelectorNameParts > 1 &&
413       Current.startsSequence(TT_SelectorName, tok::colon, tok::caret)) {
414     return true;
415   }
416   // Avoid producing inconsistent states by requiring breaks where they are not
417   // permitted for C# generic type constraints.
418   if (CurrentState.IsCSharpGenericTypeConstraint &&
419       Previous.isNot(TT_CSharpGenericTypeConstraintComma)) {
420     return false;
421   }
422   if ((startsNextParameter(Current, Style) || Previous.is(tok::semi) ||
423        (Previous.is(TT_TemplateCloser) && Current.is(TT_StartOfName) &&
424         State.Line->First->isNot(TT_AttributeSquare) && Style.isCpp() &&
425         // FIXME: This is a temporary workaround for the case where clang-format
426         // sets BreakBeforeParameter to avoid bin packing and this creates a
427         // completely unnecessary line break after a template type that isn't
428         // line-wrapped.
429         (Previous.NestingLevel == 1 ||
430          Style.BinPackParameters == FormatStyle::BPPS_BinPack)) ||
431        (Style.BreakBeforeTernaryOperators && Current.is(TT_ConditionalExpr) &&
432         Previous.isNot(tok::question)) ||
433        (!Style.BreakBeforeTernaryOperators &&
434         Previous.is(TT_ConditionalExpr))) &&
435       CurrentState.BreakBeforeParameter && !Current.isTrailingComment() &&
436       !Current.isOneOf(tok::r_paren, tok::r_brace)) {
437     return true;
438   }
439   if (CurrentState.IsChainedConditional &&
440       ((Style.BreakBeforeTernaryOperators && Current.is(TT_ConditionalExpr) &&
441         Current.is(tok::colon)) ||
442        (!Style.BreakBeforeTernaryOperators && Previous.is(TT_ConditionalExpr) &&
443         Previous.is(tok::colon)))) {
444     return true;
445   }
446   if (((Previous.is(TT_DictLiteral) && Previous.is(tok::l_brace)) ||
447        (Previous.is(TT_ArrayInitializerLSquare) &&
448         Previous.ParameterCount > 1) ||
449        opensProtoMessageField(Previous, Style)) &&
450       Style.ColumnLimit > 0 &&
451       getLengthToMatchingParen(Previous, State.Stack) + State.Column - 1 >
452           getColumnLimit(State)) {
453     return true;
454   }
455 
456   const FormatToken &BreakConstructorInitializersToken =
457       Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon
458           ? Previous
459           : Current;
460   if (BreakConstructorInitializersToken.is(TT_CtorInitializerColon) &&
461       (State.Column + State.Line->Last->TotalLength - Previous.TotalLength >
462            getColumnLimit(State) ||
463        CurrentState.BreakBeforeParameter) &&
464       (!Current.isTrailingComment() || Current.NewlinesBefore > 0) &&
465       (Style.BreakConstructorInitializers != FormatStyle::BCIS_BeforeColon ||
466        Style.ColumnLimit > 0 || Current.NewlinesBefore > 0)) {
467     return true;
468   }
469 
470   if (Current.is(TT_ObjCMethodExpr) && Previous.isNot(TT_SelectorName) &&
471       State.Line->startsWith(TT_ObjCMethodSpecifier)) {
472     return true;
473   }
474   if (Current.is(TT_SelectorName) && Previous.isNot(tok::at) &&
475       CurrentState.ObjCSelectorNameFound && CurrentState.BreakBeforeParameter &&
476       (Style.ObjCBreakBeforeNestedBlockParam ||
477        !Current.startsSequence(TT_SelectorName, tok::colon, tok::caret))) {
478     return true;
479   }
480 
481   unsigned NewLineColumn = getNewLineColumn(State);
482   if (Current.isMemberAccess() && Style.ColumnLimit != 0 &&
483       State.Column + getLengthToNextOperator(Current) > Style.ColumnLimit &&
484       (State.Column > NewLineColumn ||
485        Current.NestingLevel < State.StartOfLineLevel)) {
486     return true;
487   }
488 
489   if (startsSegmentOfBuilderTypeCall(Current) &&
490       (CurrentState.CallContinuation != 0 ||
491        CurrentState.BreakBeforeParameter) &&
492       // JavaScript is treated different here as there is a frequent pattern:
493       //   SomeFunction(function() {
494       //     ...
495       //   }.bind(...));
496       // FIXME: We should find a more generic solution to this problem.
497       !(State.Column <= NewLineColumn && Style.isJavaScript()) &&
498       !(Previous.closesScopeAfterBlock() && State.Column <= NewLineColumn)) {
499     return true;
500   }
501 
502   // If the template declaration spans multiple lines, force wrap before the
503   // function/class declaration.
504   if (Previous.ClosesTemplateDeclaration && CurrentState.BreakBeforeParameter &&
505       Current.CanBreakBefore) {
506     return true;
507   }
508 
509   if (State.Line->First->isNot(tok::kw_enum) && State.Column <= NewLineColumn)
510     return false;
511 
512   if (Style.AlwaysBreakBeforeMultilineStrings &&
513       (NewLineColumn == State.FirstIndent + Style.ContinuationIndentWidth ||
514        Previous.is(tok::comma) || Current.NestingLevel < 2) &&
515       !Previous.isOneOf(tok::kw_return, tok::lessless, tok::at,
516                         Keywords.kw_dollar) &&
517       !Previous.isOneOf(TT_InlineASMColon, TT_ConditionalExpr) &&
518       nextIsMultilineString(State)) {
519     return true;
520   }
521 
522   // Using CanBreakBefore here and below takes care of the decision whether the
523   // current style uses wrapping before or after operators for the given
524   // operator.
525   if (Previous.is(TT_BinaryOperator) && Current.CanBreakBefore) {
526     const auto PreviousPrecedence = Previous.getPrecedence();
527     if (PreviousPrecedence != prec::Assignment &&
528         CurrentState.BreakBeforeParameter && !Current.isTrailingComment()) {
529       const bool LHSIsBinaryExpr =
530           Previous.Previous && Previous.Previous->EndsBinaryExpression;
531       if (LHSIsBinaryExpr)
532         return true;
533       // If we need to break somewhere inside the LHS of a binary expression, we
534       // should also break after the operator. Otherwise, the formatting would
535       // hide the operator precedence, e.g. in:
536       //   if (aaaaaaaaaaaaaa ==
537       //           bbbbbbbbbbbbbb && c) {..
538       // For comparisons, we only apply this rule, if the LHS is a binary
539       // expression itself as otherwise, the line breaks seem superfluous.
540       // We need special cases for ">>" which we have split into two ">" while
541       // lexing in order to make template parsing easier.
542       const bool IsComparison =
543           (PreviousPrecedence == prec::Relational ||
544            PreviousPrecedence == prec::Equality ||
545            PreviousPrecedence == prec::Spaceship) &&
546           Previous.Previous &&
547           Previous.Previous->isNot(TT_BinaryOperator); // For >>.
548       if (!IsComparison)
549         return true;
550     }
551   } else if (Current.is(TT_BinaryOperator) && Current.CanBreakBefore &&
552              CurrentState.BreakBeforeParameter) {
553     return true;
554   }
555 
556   // Same as above, but for the first "<<" operator.
557   if (Current.is(tok::lessless) && Current.isNot(TT_OverloadedOperator) &&
558       CurrentState.BreakBeforeParameter && CurrentState.FirstLessLess == 0) {
559     return true;
560   }
561 
562   if (Current.NestingLevel == 0 && !Current.isTrailingComment()) {
563     // Always break after "template <...>"(*) and leading annotations. This is
564     // only for cases where the entire line does not fit on a single line as a
565     // different LineFormatter would be used otherwise.
566     // *: Except when another option interferes with that, like concepts.
567     if (Previous.ClosesTemplateDeclaration) {
568       if (Current.is(tok::kw_concept)) {
569         switch (Style.BreakBeforeConceptDeclarations) {
570         case FormatStyle::BBCDS_Allowed:
571           break;
572         case FormatStyle::BBCDS_Always:
573           return true;
574         case FormatStyle::BBCDS_Never:
575           return false;
576         }
577       }
578       if (Current.is(TT_RequiresClause)) {
579         switch (Style.RequiresClausePosition) {
580         case FormatStyle::RCPS_SingleLine:
581         case FormatStyle::RCPS_WithPreceding:
582           return false;
583         default:
584           return true;
585         }
586       }
587       return Style.BreakTemplateDeclarations != FormatStyle::BTDS_No &&
588              (Style.BreakTemplateDeclarations != FormatStyle::BTDS_Leave ||
589               Current.NewlinesBefore > 0);
590     }
591     if (Previous.is(TT_FunctionAnnotationRParen) &&
592         State.Line->Type != LT_PreprocessorDirective) {
593       return true;
594     }
595     if (Previous.is(TT_LeadingJavaAnnotation) && Current.isNot(tok::l_paren) &&
596         Current.isNot(TT_LeadingJavaAnnotation)) {
597       return true;
598     }
599   }
600 
601   if (Style.isJavaScript() && Previous.is(tok::r_paren) &&
602       Previous.is(TT_JavaAnnotation)) {
603     // Break after the closing parenthesis of TypeScript decorators before
604     // functions, getters and setters.
605     static const llvm::StringSet<> BreakBeforeDecoratedTokens = {"get", "set",
606                                                                  "function"};
607     if (BreakBeforeDecoratedTokens.contains(Current.TokenText))
608       return true;
609   }
610 
611   if (Current.is(TT_FunctionDeclarationName) &&
612       !State.Line->ReturnTypeWrapped &&
613       // Don't break before a C# function when no break after return type.
614       (!Style.isCSharp() ||
615        Style.BreakAfterReturnType > FormatStyle::RTBS_ExceptShortType) &&
616       // Don't always break between a JavaScript `function` and the function
617       // name.
618       !Style.isJavaScript() && Previous.isNot(tok::kw_template) &&
619       CurrentState.BreakBeforeParameter) {
620     return true;
621   }
622 
623   // The following could be precomputed as they do not depend on the state.
624   // However, as they should take effect only if the UnwrappedLine does not fit
625   // into the ColumnLimit, they are checked here in the ContinuationIndenter.
626   if (Style.ColumnLimit != 0 && Previous.is(BK_Block) &&
627       Previous.is(tok::l_brace) &&
628       !Current.isOneOf(tok::r_brace, tok::comment)) {
629     return true;
630   }
631 
632   if (Current.is(tok::lessless) &&
633       ((Previous.is(tok::identifier) && Previous.TokenText == "endl") ||
634        (Previous.Tok.isLiteral() && (Previous.TokenText.ends_with("\\n\"") ||
635                                      Previous.TokenText == "\'\\n\'")))) {
636     return true;
637   }
638 
639   if (Previous.is(TT_BlockComment) && Previous.IsMultiline)
640     return true;
641 
642   if (State.NoContinuation)
643     return true;
644 
645   return false;
646 }
647 
648 unsigned ContinuationIndenter::addTokenToState(LineState &State, bool Newline,
649                                                bool DryRun,
650                                                unsigned ExtraSpaces) {
651   const FormatToken &Current = *State.NextToken;
652   assert(State.NextToken->Previous);
653   const FormatToken &Previous = *State.NextToken->Previous;
654 
655   assert(!State.Stack.empty());
656   State.NoContinuation = false;
657 
658   if (Current.is(TT_ImplicitStringLiteral) &&
659       (!Previous.Tok.getIdentifierInfo() ||
660        Previous.Tok.getIdentifierInfo()->getPPKeywordID() ==
661            tok::pp_not_keyword)) {
662     unsigned EndColumn =
663         SourceMgr.getSpellingColumnNumber(Current.WhitespaceRange.getEnd());
664     if (Current.LastNewlineOffset != 0) {
665       // If there is a newline within this token, the final column will solely
666       // determined by the current end column.
667       State.Column = EndColumn;
668     } else {
669       unsigned StartColumn =
670           SourceMgr.getSpellingColumnNumber(Current.WhitespaceRange.getBegin());
671       assert(EndColumn >= StartColumn);
672       State.Column += EndColumn - StartColumn;
673     }
674     moveStateToNextToken(State, DryRun, /*Newline=*/false);
675     return 0;
676   }
677 
678   unsigned Penalty = 0;
679   if (Newline)
680     Penalty = addTokenOnNewLine(State, DryRun);
681   else
682     addTokenOnCurrentLine(State, DryRun, ExtraSpaces);
683 
684   return moveStateToNextToken(State, DryRun, Newline) + Penalty;
685 }
686 
687 void ContinuationIndenter::addTokenOnCurrentLine(LineState &State, bool DryRun,
688                                                  unsigned ExtraSpaces) {
689   FormatToken &Current = *State.NextToken;
690   assert(State.NextToken->Previous);
691   const FormatToken &Previous = *State.NextToken->Previous;
692   auto &CurrentState = State.Stack.back();
693 
694   bool DisallowLineBreaksOnThisLine =
695       Style.LambdaBodyIndentation == FormatStyle::LBI_Signature &&
696       // Deal with lambda arguments in C++. The aim here is to ensure that we
697       // don't over-indent lambda function bodies when lambdas are passed as
698       // arguments to function calls. We do this by ensuring that either all
699       // arguments (including any lambdas) go on the same line as the function
700       // call, or we break before the first argument.
701       Style.isCpp() && [&] {
702         // For example, `/*Newline=*/false`.
703         if (Previous.is(TT_BlockComment) && Current.SpacesRequiredBefore == 0)
704           return false;
705         const auto *PrevNonComment = Current.getPreviousNonComment();
706         if (!PrevNonComment || PrevNonComment->isNot(tok::l_paren))
707           return false;
708         if (Current.isOneOf(tok::comment, tok::l_paren, TT_LambdaLSquare))
709           return false;
710         auto BlockParameterCount = PrevNonComment->BlockParameterCount;
711         if (BlockParameterCount == 0)
712           return false;
713 
714         // Multiple lambdas in the same function call.
715         if (BlockParameterCount > 1)
716           return true;
717 
718         // A lambda followed by another arg.
719         if (!PrevNonComment->Role)
720           return false;
721         auto Comma = PrevNonComment->Role->lastComma();
722         if (!Comma)
723           return false;
724         auto Next = Comma->getNextNonComment();
725         return Next &&
726                !Next->isOneOf(TT_LambdaLSquare, tok::l_brace, tok::caret);
727       }();
728 
729   if (DisallowLineBreaksOnThisLine)
730     State.NoLineBreak = true;
731 
732   if (Current.is(tok::equal) &&
733       (State.Line->First->is(tok::kw_for) || Current.NestingLevel == 0) &&
734       CurrentState.VariablePos == 0 &&
735       (!Previous.Previous ||
736        Previous.Previous->isNot(TT_DesignatedInitializerPeriod))) {
737     CurrentState.VariablePos = State.Column;
738     // Move over * and & if they are bound to the variable name.
739     const FormatToken *Tok = &Previous;
740     while (Tok && CurrentState.VariablePos >= Tok->ColumnWidth) {
741       CurrentState.VariablePos -= Tok->ColumnWidth;
742       if (Tok->SpacesRequiredBefore != 0)
743         break;
744       Tok = Tok->Previous;
745     }
746     if (Previous.PartOfMultiVariableDeclStmt)
747       CurrentState.LastSpace = CurrentState.VariablePos;
748   }
749 
750   unsigned Spaces = Current.SpacesRequiredBefore + ExtraSpaces;
751 
752   // Indent preprocessor directives after the hash if required.
753   int PPColumnCorrection = 0;
754   if (Style.IndentPPDirectives == FormatStyle::PPDIS_AfterHash &&
755       Previous.is(tok::hash) && State.FirstIndent > 0 &&
756       &Previous == State.Line->First &&
757       (State.Line->Type == LT_PreprocessorDirective ||
758        State.Line->Type == LT_ImportStatement)) {
759     Spaces += State.FirstIndent;
760 
761     // For preprocessor indent with tabs, State.Column will be 1 because of the
762     // hash. This causes second-level indents onward to have an extra space
763     // after the tabs. We avoid this misalignment by subtracting 1 from the
764     // column value passed to replaceWhitespace().
765     if (Style.UseTab != FormatStyle::UT_Never)
766       PPColumnCorrection = -1;
767   }
768 
769   if (!DryRun) {
770     Whitespaces.replaceWhitespace(Current, /*Newlines=*/0, Spaces,
771                                   State.Column + Spaces + PPColumnCorrection,
772                                   /*IsAligned=*/false, State.Line->InMacroBody);
773   }
774 
775   // If "BreakBeforeInheritanceComma" mode, don't break within the inheritance
776   // declaration unless there is multiple inheritance.
777   if (Style.BreakInheritanceList == FormatStyle::BILS_BeforeComma &&
778       Current.is(TT_InheritanceColon)) {
779     CurrentState.NoLineBreak = true;
780   }
781   if (Style.BreakInheritanceList == FormatStyle::BILS_AfterColon &&
782       Previous.is(TT_InheritanceColon)) {
783     CurrentState.NoLineBreak = true;
784   }
785 
786   if (Current.is(TT_SelectorName) && !CurrentState.ObjCSelectorNameFound) {
787     unsigned MinIndent = std::max(
788         State.FirstIndent + Style.ContinuationIndentWidth, CurrentState.Indent);
789     unsigned FirstColonPos = State.Column + Spaces + Current.ColumnWidth;
790     if (Current.LongestObjCSelectorName == 0)
791       CurrentState.AlignColons = false;
792     else if (MinIndent + Current.LongestObjCSelectorName > FirstColonPos)
793       CurrentState.ColonPos = MinIndent + Current.LongestObjCSelectorName;
794     else
795       CurrentState.ColonPos = FirstColonPos;
796   }
797 
798   // In "AlwaysBreak" or "BlockIndent" mode, enforce wrapping directly after the
799   // parenthesis by disallowing any further line breaks if there is no line
800   // break after the opening parenthesis. Don't break if it doesn't conserve
801   // columns.
802   auto IsOpeningBracket = [&](const FormatToken &Tok) {
803     auto IsStartOfBracedList = [&]() {
804       return Tok.is(tok::l_brace) && Tok.isNot(BK_Block) &&
805              Style.Cpp11BracedListStyle;
806     };
807     if (!Tok.isOneOf(tok::l_paren, TT_TemplateOpener, tok::l_square) &&
808         !IsStartOfBracedList()) {
809       return false;
810     }
811     if (!Tok.Previous)
812       return true;
813     if (Tok.Previous->isIf())
814       return Style.AlignAfterOpenBracket == FormatStyle::BAS_AlwaysBreak;
815     return !Tok.Previous->isOneOf(TT_CastRParen, tok::kw_for, tok::kw_while,
816                                   tok::kw_switch) &&
817            !(Style.isJavaScript() && Tok.Previous->is(Keywords.kw_await));
818   };
819   auto IsFunctionCallParen = [](const FormatToken &Tok) {
820     return Tok.is(tok::l_paren) && Tok.ParameterCount > 0 && Tok.Previous &&
821            Tok.Previous->is(tok::identifier);
822   };
823   auto IsInTemplateString = [this](const FormatToken &Tok) {
824     if (!Style.isJavaScript())
825       return false;
826     for (const auto *Prev = &Tok; Prev; Prev = Prev->Previous) {
827       if (Prev->is(TT_TemplateString) && Prev->opensScope())
828         return true;
829       if (Prev->opensScope() ||
830           (Prev->is(TT_TemplateString) && Prev->closesScope())) {
831         break;
832       }
833     }
834     return false;
835   };
836   // Identifies simple (no expression) one-argument function calls.
837   auto StartsSimpleOneArgList = [&](const FormatToken &TokAfterLParen) {
838     assert(TokAfterLParen.isNot(tok::comment) || TokAfterLParen.Next);
839     const auto &Tok =
840         TokAfterLParen.is(tok::comment) ? *TokAfterLParen.Next : TokAfterLParen;
841     if (!Tok.FakeLParens.empty() && Tok.FakeLParens.back() > prec::Unknown)
842       return false;
843     // Nested calls that involve `new` expressions also look like simple
844     // function calls, eg:
845     // - foo(new Bar())
846     // - foo(::new Bar())
847     if (Tok.is(tok::kw_new) || Tok.startsSequence(tok::coloncolon, tok::kw_new))
848       return true;
849     if (Tok.is(TT_UnaryOperator) ||
850         (Style.isJavaScript() &&
851          Tok.isOneOf(tok::ellipsis, Keywords.kw_await))) {
852       return true;
853     }
854     const auto *Previous = Tok.Previous;
855     if (!Previous || (!Previous->isOneOf(TT_FunctionDeclarationLParen,
856                                          TT_LambdaDefinitionLParen) &&
857                       !IsFunctionCallParen(*Previous))) {
858       return true;
859     }
860     if (IsOpeningBracket(Tok) || IsInTemplateString(Tok))
861       return true;
862     const auto *Next = Tok.Next;
863     return !Next || Next->isMemberAccess() ||
864            Next->is(TT_FunctionDeclarationLParen) || IsFunctionCallParen(*Next);
865   };
866   if ((Style.AlignAfterOpenBracket == FormatStyle::BAS_AlwaysBreak ||
867        Style.AlignAfterOpenBracket == FormatStyle::BAS_BlockIndent) &&
868       IsOpeningBracket(Previous) && State.Column > getNewLineColumn(State) &&
869       // Don't do this for simple (no expressions) one-argument function calls
870       // as that feels like needlessly wasting whitespace, e.g.:
871       //
872       //   caaaaaaaaaaaall(
873       //       caaaaaaaaaaaall(
874       //           caaaaaaaaaaaall(
875       //               caaaaaaaaaaaaaaaaaaaaaaall(aaaaaaaaaaaaaa, aaaaaaaaa))));
876       //  or
877       //  caaaaaaaaaaaaaaaaaaaaal(
878       //       new SomethingElseeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee());
879       !StartsSimpleOneArgList(Current)) {
880     CurrentState.NoLineBreak = true;
881   }
882 
883   if (Previous.is(TT_TemplateString) && Previous.opensScope())
884     CurrentState.NoLineBreak = true;
885 
886   // Align following lines within parentheses / brackets if configured.
887   // Note: This doesn't apply to macro expansion lines, which are MACRO( , , )
888   // with args as children of the '(' and ',' tokens. It does not make sense to
889   // align the commas with the opening paren.
890   if (Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign &&
891       !CurrentState.IsCSharpGenericTypeConstraint && Previous.opensScope() &&
892       Previous.isNot(TT_ObjCMethodExpr) && Previous.isNot(TT_RequiresClause) &&
893       Previous.isNot(TT_TableGenDAGArgOpener) &&
894       Previous.isNot(TT_TableGenDAGArgOpenerToBreak) &&
895       !(Current.MacroParent && Previous.MacroParent) &&
896       (Current.isNot(TT_LineComment) ||
897        Previous.isOneOf(BK_BracedInit, TT_VerilogMultiLineListLParen)) &&
898       !IsInTemplateString(Current)) {
899     CurrentState.Indent = State.Column + Spaces;
900     CurrentState.IsAligned = true;
901   }
902   if (CurrentState.AvoidBinPacking && startsNextParameter(Current, Style))
903     CurrentState.NoLineBreak = true;
904   if (mustBreakBinaryOperation(Current, Style))
905     CurrentState.NoLineBreak = true;
906 
907   if (startsSegmentOfBuilderTypeCall(Current) &&
908       State.Column > getNewLineColumn(State)) {
909     CurrentState.ContainsUnwrappedBuilder = true;
910   }
911 
912   if (Current.is(TT_LambdaArrow) && Style.Language == FormatStyle::LK_Java)
913     CurrentState.NoLineBreak = true;
914   if (Current.isMemberAccess() && Previous.is(tok::r_paren) &&
915       (Previous.MatchingParen &&
916        (Previous.TotalLength - Previous.MatchingParen->TotalLength > 10))) {
917     // If there is a function call with long parameters, break before trailing
918     // calls. This prevents things like:
919     //   EXPECT_CALL(SomeLongParameter).Times(
920     //       2);
921     // We don't want to do this for short parameters as they can just be
922     // indexes.
923     CurrentState.NoLineBreak = true;
924   }
925 
926   // Don't allow the RHS of an operator to be split over multiple lines unless
927   // there is a line-break right after the operator.
928   // Exclude relational operators, as there, it is always more desirable to
929   // have the LHS 'left' of the RHS.
930   const FormatToken *P = Current.getPreviousNonComment();
931   if (Current.isNot(tok::comment) && P &&
932       (P->isOneOf(TT_BinaryOperator, tok::comma) ||
933        (P->is(TT_ConditionalExpr) && P->is(tok::colon))) &&
934       !P->isOneOf(TT_OverloadedOperator, TT_CtorInitializerComma) &&
935       P->getPrecedence() != prec::Assignment &&
936       P->getPrecedence() != prec::Relational &&
937       P->getPrecedence() != prec::Spaceship) {
938     bool BreakBeforeOperator =
939         P->MustBreakBefore || P->is(tok::lessless) ||
940         (P->is(TT_BinaryOperator) &&
941          Style.BreakBeforeBinaryOperators != FormatStyle::BOS_None) ||
942         (P->is(TT_ConditionalExpr) && Style.BreakBeforeTernaryOperators);
943     // Don't do this if there are only two operands. In these cases, there is
944     // always a nice vertical separation between them and the extra line break
945     // does not help.
946     bool HasTwoOperands = P->OperatorIndex == 0 && !P->NextOperator &&
947                           P->isNot(TT_ConditionalExpr);
948     if ((!BreakBeforeOperator &&
949          !(HasTwoOperands &&
950            Style.AlignOperands != FormatStyle::OAS_DontAlign)) ||
951         (!CurrentState.LastOperatorWrapped && BreakBeforeOperator)) {
952       CurrentState.NoLineBreakInOperand = true;
953     }
954   }
955 
956   State.Column += Spaces;
957   if (Current.isNot(tok::comment) && Previous.is(tok::l_paren) &&
958       Previous.Previous &&
959       (Previous.Previous->is(tok::kw_for) || Previous.Previous->isIf())) {
960     // Treat the condition inside an if as if it was a second function
961     // parameter, i.e. let nested calls have a continuation indent.
962     CurrentState.LastSpace = State.Column;
963     CurrentState.NestedBlockIndent = State.Column;
964   } else if (!Current.isOneOf(tok::comment, tok::caret) &&
965              ((Previous.is(tok::comma) &&
966                Previous.isNot(TT_OverloadedOperator)) ||
967               (Previous.is(tok::colon) && Previous.is(TT_ObjCMethodExpr)))) {
968     CurrentState.LastSpace = State.Column;
969   } else if (Previous.is(TT_CtorInitializerColon) &&
970              (!Current.isTrailingComment() || Current.NewlinesBefore > 0) &&
971              Style.BreakConstructorInitializers ==
972                  FormatStyle::BCIS_AfterColon) {
973     CurrentState.Indent = State.Column;
974     CurrentState.LastSpace = State.Column;
975   } else if (Previous.isOneOf(TT_ConditionalExpr, TT_CtorInitializerColon)) {
976     CurrentState.LastSpace = State.Column;
977   } else if (Previous.is(TT_BinaryOperator) &&
978              ((Previous.getPrecedence() != prec::Assignment &&
979                (Previous.isNot(tok::lessless) || Previous.OperatorIndex != 0 ||
980                 Previous.NextOperator)) ||
981               Current.StartsBinaryExpression)) {
982     // Indent relative to the RHS of the expression unless this is a simple
983     // assignment without binary expression on the RHS.
984     if (Style.BreakBeforeBinaryOperators == FormatStyle::BOS_None)
985       CurrentState.LastSpace = State.Column;
986   } else if (Previous.is(TT_InheritanceColon)) {
987     CurrentState.Indent = State.Column;
988     CurrentState.LastSpace = State.Column;
989   } else if (Current.is(TT_CSharpGenericTypeConstraintColon)) {
990     CurrentState.ColonPos = State.Column;
991   } else if (Previous.opensScope()) {
992     // If a function has a trailing call, indent all parameters from the
993     // opening parenthesis. This avoids confusing indents like:
994     //   OuterFunction(InnerFunctionCall( // break
995     //       ParameterToInnerFunction))   // break
996     //       .SecondInnerFunctionCall();
997     if (Previous.MatchingParen) {
998       const FormatToken *Next = Previous.MatchingParen->getNextNonComment();
999       if (Next && Next->isMemberAccess() && State.Stack.size() > 1 &&
1000           State.Stack[State.Stack.size() - 2].CallContinuation == 0) {
1001         CurrentState.LastSpace = State.Column;
1002       }
1003     }
1004   }
1005 }
1006 
1007 unsigned ContinuationIndenter::addTokenOnNewLine(LineState &State,
1008                                                  bool DryRun) {
1009   FormatToken &Current = *State.NextToken;
1010   assert(State.NextToken->Previous);
1011   const FormatToken &Previous = *State.NextToken->Previous;
1012   auto &CurrentState = State.Stack.back();
1013 
1014   // Extra penalty that needs to be added because of the way certain line
1015   // breaks are chosen.
1016   unsigned Penalty = 0;
1017 
1018   const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
1019   const FormatToken *NextNonComment = Previous.getNextNonComment();
1020   if (!NextNonComment)
1021     NextNonComment = &Current;
1022   // The first line break on any NestingLevel causes an extra penalty in order
1023   // prefer similar line breaks.
1024   if (!CurrentState.ContainsLineBreak)
1025     Penalty += 15;
1026   CurrentState.ContainsLineBreak = true;
1027 
1028   Penalty += State.NextToken->SplitPenalty;
1029 
1030   // Breaking before the first "<<" is generally not desirable if the LHS is
1031   // short. Also always add the penalty if the LHS is split over multiple lines
1032   // to avoid unnecessary line breaks that just work around this penalty.
1033   if (NextNonComment->is(tok::lessless) && CurrentState.FirstLessLess == 0 &&
1034       (State.Column <= Style.ColumnLimit / 3 ||
1035        CurrentState.BreakBeforeParameter)) {
1036     Penalty += Style.PenaltyBreakFirstLessLess;
1037   }
1038 
1039   State.Column = getNewLineColumn(State);
1040 
1041   // Add Penalty proportional to amount of whitespace away from FirstColumn
1042   // This tends to penalize several lines that are far-right indented,
1043   // and prefers a line-break prior to such a block, e.g:
1044   //
1045   // Constructor() :
1046   //   member(value), looooooooooooooooong_member(
1047   //                      looooooooooong_call(param_1, param_2, param_3))
1048   // would then become
1049   // Constructor() :
1050   //   member(value),
1051   //   looooooooooooooooong_member(
1052   //       looooooooooong_call(param_1, param_2, param_3))
1053   if (State.Column > State.FirstIndent) {
1054     Penalty +=
1055         Style.PenaltyIndentedWhitespace * (State.Column - State.FirstIndent);
1056   }
1057 
1058   // Indent nested blocks relative to this column, unless in a very specific
1059   // JavaScript special case where:
1060   //
1061   //   var loooooong_name =
1062   //       function() {
1063   //     // code
1064   //   }
1065   //
1066   // is common and should be formatted like a free-standing function. The same
1067   // goes for wrapping before the lambda return type arrow.
1068   if (Current.isNot(TT_LambdaArrow) &&
1069       (!Style.isJavaScript() || Current.NestingLevel != 0 ||
1070        !PreviousNonComment || PreviousNonComment->isNot(tok::equal) ||
1071        !Current.isOneOf(Keywords.kw_async, Keywords.kw_function))) {
1072     CurrentState.NestedBlockIndent = State.Column;
1073   }
1074 
1075   if (NextNonComment->isMemberAccess()) {
1076     if (CurrentState.CallContinuation == 0)
1077       CurrentState.CallContinuation = State.Column;
1078   } else if (NextNonComment->is(TT_SelectorName)) {
1079     if (!CurrentState.ObjCSelectorNameFound) {
1080       if (NextNonComment->LongestObjCSelectorName == 0) {
1081         CurrentState.AlignColons = false;
1082       } else {
1083         CurrentState.ColonPos =
1084             (shouldIndentWrappedSelectorName(Style, State.Line->Type)
1085                  ? std::max(CurrentState.Indent,
1086                             State.FirstIndent + Style.ContinuationIndentWidth)
1087                  : CurrentState.Indent) +
1088             std::max(NextNonComment->LongestObjCSelectorName,
1089                      NextNonComment->ColumnWidth);
1090       }
1091     } else if (CurrentState.AlignColons &&
1092                CurrentState.ColonPos <= NextNonComment->ColumnWidth) {
1093       CurrentState.ColonPos = State.Column + NextNonComment->ColumnWidth;
1094     }
1095   } else if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
1096              PreviousNonComment->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral)) {
1097     // FIXME: This is hacky, find a better way. The problem is that in an ObjC
1098     // method expression, the block should be aligned to the line starting it,
1099     // e.g.:
1100     //   [aaaaaaaaaaaaaaa aaaaaaaaa: \\ break for some reason
1101     //                        ^(int *i) {
1102     //                            // ...
1103     //                        }];
1104     // Thus, we set LastSpace of the next higher NestingLevel, to which we move
1105     // when we consume all of the "}"'s FakeRParens at the "{".
1106     if (State.Stack.size() > 1) {
1107       State.Stack[State.Stack.size() - 2].LastSpace =
1108           std::max(CurrentState.LastSpace, CurrentState.Indent) +
1109           Style.ContinuationIndentWidth;
1110     }
1111   }
1112 
1113   if ((PreviousNonComment &&
1114        PreviousNonComment->isOneOf(tok::comma, tok::semi) &&
1115        !CurrentState.AvoidBinPacking) ||
1116       Previous.is(TT_BinaryOperator)) {
1117     CurrentState.BreakBeforeParameter = false;
1118   }
1119   if (PreviousNonComment &&
1120       (PreviousNonComment->isOneOf(TT_TemplateCloser, TT_JavaAnnotation) ||
1121        PreviousNonComment->ClosesRequiresClause) &&
1122       Current.NestingLevel == 0) {
1123     CurrentState.BreakBeforeParameter = false;
1124   }
1125   if (NextNonComment->is(tok::question) ||
1126       (PreviousNonComment && PreviousNonComment->is(tok::question))) {
1127     CurrentState.BreakBeforeParameter = true;
1128   }
1129   if (Current.is(TT_BinaryOperator) && Current.CanBreakBefore)
1130     CurrentState.BreakBeforeParameter = false;
1131 
1132   if (!DryRun) {
1133     unsigned MaxEmptyLinesToKeep = Style.MaxEmptyLinesToKeep + 1;
1134     if (Current.is(tok::r_brace) && Current.MatchingParen &&
1135         // Only strip trailing empty lines for l_braces that have children, i.e.
1136         // for function expressions (lambdas, arrows, etc).
1137         !Current.MatchingParen->Children.empty()) {
1138       // lambdas and arrow functions are expressions, thus their r_brace is not
1139       // on its own line, and thus not covered by UnwrappedLineFormatter's logic
1140       // about removing empty lines on closing blocks. Special case them here.
1141       MaxEmptyLinesToKeep = 1;
1142     }
1143     unsigned Newlines =
1144         std::max(1u, std::min(Current.NewlinesBefore, MaxEmptyLinesToKeep));
1145     bool ContinuePPDirective =
1146         State.Line->InPPDirective && State.Line->Type != LT_ImportStatement;
1147     Whitespaces.replaceWhitespace(Current, Newlines, State.Column, State.Column,
1148                                   CurrentState.IsAligned, ContinuePPDirective);
1149   }
1150 
1151   if (!Current.isTrailingComment())
1152     CurrentState.LastSpace = State.Column;
1153   if (Current.is(tok::lessless)) {
1154     // If we are breaking before a "<<", we always want to indent relative to
1155     // RHS. This is necessary only for "<<", as we special-case it and don't
1156     // always indent relative to the RHS.
1157     CurrentState.LastSpace += 3; // 3 -> width of "<< ".
1158   }
1159 
1160   State.StartOfLineLevel = Current.NestingLevel;
1161   State.LowestLevelOnLine = Current.NestingLevel;
1162 
1163   // Any break on this level means that the parent level has been broken
1164   // and we need to avoid bin packing there.
1165   bool NestedBlockSpecialCase =
1166       (!Style.isCpp() && Current.is(tok::r_brace) && State.Stack.size() > 1 &&
1167        State.Stack[State.Stack.size() - 2].NestedBlockInlined) ||
1168       (Style.Language == FormatStyle::LK_ObjC && Current.is(tok::r_brace) &&
1169        State.Stack.size() > 1 && !Style.ObjCBreakBeforeNestedBlockParam);
1170   // Do not force parameter break for statements with requires expressions.
1171   NestedBlockSpecialCase =
1172       NestedBlockSpecialCase ||
1173       (Current.MatchingParen &&
1174        Current.MatchingParen->is(TT_RequiresExpressionLBrace));
1175   if (!NestedBlockSpecialCase) {
1176     auto ParentLevelIt = std::next(State.Stack.rbegin());
1177     if (Style.LambdaBodyIndentation == FormatStyle::LBI_OuterScope &&
1178         Current.MatchingParen && Current.MatchingParen->is(TT_LambdaLBrace)) {
1179       // If the first character on the new line is a lambda's closing brace, the
1180       // stack still contains that lambda's parenthesis. As such, we need to
1181       // recurse further down the stack than usual to find the parenthesis level
1182       // containing the lambda, which is where we want to set
1183       // BreakBeforeParameter.
1184       //
1185       // We specifically special case "OuterScope"-formatted lambdas here
1186       // because, when using that setting, breaking before the parameter
1187       // directly following the lambda is particularly unsightly. However, when
1188       // "OuterScope" is not set, the logic to find the parent parenthesis level
1189       // still appears to be sometimes incorrect. It has not been fixed yet
1190       // because it would lead to significant changes in existing behaviour.
1191       //
1192       // TODO: fix the non-"OuterScope" case too.
1193       auto FindCurrentLevel = [&](const auto &It) {
1194         return std::find_if(It, State.Stack.rend(), [](const auto &PState) {
1195           return PState.Tok != nullptr; // Ignore fake parens.
1196         });
1197       };
1198       auto MaybeIncrement = [&](const auto &It) {
1199         return It != State.Stack.rend() ? std::next(It) : It;
1200       };
1201       auto LambdaLevelIt = FindCurrentLevel(State.Stack.rbegin());
1202       auto LevelContainingLambdaIt =
1203           FindCurrentLevel(MaybeIncrement(LambdaLevelIt));
1204       ParentLevelIt = MaybeIncrement(LevelContainingLambdaIt);
1205     }
1206     for (auto I = ParentLevelIt, E = State.Stack.rend(); I != E; ++I)
1207       I->BreakBeforeParameter = true;
1208   }
1209 
1210   if (PreviousNonComment &&
1211       !PreviousNonComment->isOneOf(tok::comma, tok::colon, tok::semi) &&
1212       ((PreviousNonComment->isNot(TT_TemplateCloser) &&
1213         !PreviousNonComment->ClosesRequiresClause) ||
1214        Current.NestingLevel != 0) &&
1215       !PreviousNonComment->isOneOf(
1216           TT_BinaryOperator, TT_FunctionAnnotationRParen, TT_JavaAnnotation,
1217           TT_LeadingJavaAnnotation) &&
1218       Current.isNot(TT_BinaryOperator) && !PreviousNonComment->opensScope() &&
1219       // We don't want to enforce line breaks for subsequent arguments just
1220       // because we have been forced to break before a lambda body.
1221       (!Style.BraceWrapping.BeforeLambdaBody ||
1222        Current.isNot(TT_LambdaLBrace))) {
1223     CurrentState.BreakBeforeParameter = true;
1224   }
1225 
1226   // If we break after { or the [ of an array initializer, we should also break
1227   // before the corresponding } or ].
1228   if (PreviousNonComment &&
1229       (PreviousNonComment->isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) ||
1230        opensProtoMessageField(*PreviousNonComment, Style))) {
1231     CurrentState.BreakBeforeClosingBrace = true;
1232   }
1233 
1234   if (PreviousNonComment && PreviousNonComment->is(tok::l_paren)) {
1235     CurrentState.BreakBeforeClosingParen =
1236         Style.AlignAfterOpenBracket == FormatStyle::BAS_BlockIndent;
1237   }
1238 
1239   if (CurrentState.AvoidBinPacking) {
1240     // If we are breaking after '(', '{', '<', or this is the break after a ':'
1241     // to start a member initializer list in a constructor, this should not
1242     // be considered bin packing unless the relevant AllowAll option is false or
1243     // this is a dict/object literal.
1244     bool PreviousIsBreakingCtorInitializerColon =
1245         PreviousNonComment && PreviousNonComment->is(TT_CtorInitializerColon) &&
1246         Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon;
1247     bool AllowAllConstructorInitializersOnNextLine =
1248         Style.PackConstructorInitializers == FormatStyle::PCIS_NextLine ||
1249         Style.PackConstructorInitializers == FormatStyle::PCIS_NextLineOnly;
1250     if (!(Previous.isOneOf(tok::l_paren, tok::l_brace, TT_BinaryOperator) ||
1251           PreviousIsBreakingCtorInitializerColon) ||
1252         (!Style.AllowAllParametersOfDeclarationOnNextLine &&
1253          State.Line->MustBeDeclaration) ||
1254         (!Style.AllowAllArgumentsOnNextLine &&
1255          !State.Line->MustBeDeclaration) ||
1256         (!AllowAllConstructorInitializersOnNextLine &&
1257          PreviousIsBreakingCtorInitializerColon) ||
1258         Previous.is(TT_DictLiteral)) {
1259       CurrentState.BreakBeforeParameter = true;
1260     }
1261 
1262     // If we are breaking after a ':' to start a member initializer list,
1263     // and we allow all arguments on the next line, we should not break
1264     // before the next parameter.
1265     if (PreviousIsBreakingCtorInitializerColon &&
1266         AllowAllConstructorInitializersOnNextLine) {
1267       CurrentState.BreakBeforeParameter = false;
1268     }
1269   }
1270 
1271   if (mustBreakBinaryOperation(Current, Style))
1272     CurrentState.BreakBeforeParameter = true;
1273 
1274   return Penalty;
1275 }
1276 
1277 unsigned ContinuationIndenter::getNewLineColumn(const LineState &State) {
1278   if (!State.NextToken || !State.NextToken->Previous)
1279     return 0;
1280 
1281   FormatToken &Current = *State.NextToken;
1282   const auto &CurrentState = State.Stack.back();
1283 
1284   if (CurrentState.IsCSharpGenericTypeConstraint &&
1285       Current.isNot(TT_CSharpGenericTypeConstraint)) {
1286     return CurrentState.ColonPos + 2;
1287   }
1288 
1289   const FormatToken &Previous = *Current.Previous;
1290   // If we are continuing an expression, we want to use the continuation indent.
1291   unsigned ContinuationIndent =
1292       std::max(CurrentState.LastSpace, CurrentState.Indent) +
1293       Style.ContinuationIndentWidth;
1294   const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
1295   const FormatToken *NextNonComment = Previous.getNextNonComment();
1296   if (!NextNonComment)
1297     NextNonComment = &Current;
1298 
1299   // Java specific bits.
1300   if (Style.Language == FormatStyle::LK_Java &&
1301       Current.isOneOf(Keywords.kw_implements, Keywords.kw_extends)) {
1302     return std::max(CurrentState.LastSpace,
1303                     CurrentState.Indent + Style.ContinuationIndentWidth);
1304   }
1305 
1306   // Indentation of the statement following a Verilog case label is taken care
1307   // of in moveStateToNextToken.
1308   if (Style.isVerilog() && PreviousNonComment &&
1309       Keywords.isVerilogEndOfLabel(*PreviousNonComment)) {
1310     return State.FirstIndent;
1311   }
1312 
1313   if (Style.BreakBeforeBraces == FormatStyle::BS_Whitesmiths &&
1314       State.Line->First->is(tok::kw_enum)) {
1315     return (Style.IndentWidth * State.Line->First->IndentLevel) +
1316            Style.IndentWidth;
1317   }
1318 
1319   if ((NextNonComment->is(tok::l_brace) && NextNonComment->is(BK_Block)) ||
1320       (Style.isVerilog() && Keywords.isVerilogBegin(*NextNonComment))) {
1321     if (Current.NestingLevel == 0 ||
1322         (Style.LambdaBodyIndentation == FormatStyle::LBI_OuterScope &&
1323          State.NextToken->is(TT_LambdaLBrace))) {
1324       return State.FirstIndent;
1325     }
1326     return CurrentState.Indent;
1327   }
1328   if (Current.is(TT_LambdaArrow) &&
1329       Previous.isOneOf(tok::kw_noexcept, tok::kw_mutable, tok::kw_constexpr,
1330                        tok::kw_consteval, tok::kw_static, TT_AttributeSquare)) {
1331     return ContinuationIndent;
1332   }
1333   if ((Current.isOneOf(tok::r_brace, tok::r_square) ||
1334        (Current.is(tok::greater) && (Style.isProto() || Style.isTableGen()))) &&
1335       State.Stack.size() > 1) {
1336     if (Current.closesBlockOrBlockTypeList(Style))
1337       return State.Stack[State.Stack.size() - 2].NestedBlockIndent;
1338     if (Current.MatchingParen && Current.MatchingParen->is(BK_BracedInit))
1339       return State.Stack[State.Stack.size() - 2].LastSpace;
1340     return State.FirstIndent;
1341   }
1342   // Indent a closing parenthesis at the previous level if followed by a semi,
1343   // const, or opening brace. This allows indentations such as:
1344   //     foo(
1345   //       a,
1346   //     );
1347   //     int Foo::getter(
1348   //         //
1349   //     ) const {
1350   //       return foo;
1351   //     }
1352   //     function foo(
1353   //       a,
1354   //     ) {
1355   //       code(); //
1356   //     }
1357   if (Current.is(tok::r_paren) && State.Stack.size() > 1 &&
1358       (!Current.Next ||
1359        Current.Next->isOneOf(tok::semi, tok::kw_const, tok::l_brace))) {
1360     return State.Stack[State.Stack.size() - 2].LastSpace;
1361   }
1362   // When DAGArg closer exists top of line, it should be aligned in the similar
1363   // way as function call above.
1364   if (Style.isTableGen() && Current.is(TT_TableGenDAGArgCloser) &&
1365       State.Stack.size() > 1) {
1366     return State.Stack[State.Stack.size() - 2].LastSpace;
1367   }
1368   if (Style.AlignAfterOpenBracket == FormatStyle::BAS_BlockIndent &&
1369       (Current.is(tok::r_paren) ||
1370        (Current.is(tok::r_brace) && Current.MatchingParen &&
1371         Current.MatchingParen->is(BK_BracedInit))) &&
1372       State.Stack.size() > 1) {
1373     return State.Stack[State.Stack.size() - 2].LastSpace;
1374   }
1375   if (NextNonComment->is(TT_TemplateString) && NextNonComment->closesScope())
1376     return State.Stack[State.Stack.size() - 2].LastSpace;
1377   // Field labels in a nested type should be aligned to the brace. For example
1378   // in ProtoBuf:
1379   //   optional int32 b = 2 [(foo_options) = {aaaaaaaaaaaaaaaaaaa: 123,
1380   //                                          bbbbbbbbbbbbbbbbbbbbbbbb:"baz"}];
1381   // For Verilog, a quote following a brace is treated as an identifier.  And
1382   // Both braces and colons get annotated as TT_DictLiteral.  So we have to
1383   // check.
1384   if (Current.is(tok::identifier) && Current.Next &&
1385       (!Style.isVerilog() || Current.Next->is(tok::colon)) &&
1386       (Current.Next->is(TT_DictLiteral) ||
1387        (Style.isProto() && Current.Next->isOneOf(tok::less, tok::l_brace)))) {
1388     return CurrentState.Indent;
1389   }
1390   if (NextNonComment->is(TT_ObjCStringLiteral) &&
1391       State.StartOfStringLiteral != 0) {
1392     return State.StartOfStringLiteral - 1;
1393   }
1394   if (NextNonComment->isStringLiteral() && State.StartOfStringLiteral != 0)
1395     return State.StartOfStringLiteral;
1396   if (NextNonComment->is(tok::lessless) && CurrentState.FirstLessLess != 0)
1397     return CurrentState.FirstLessLess;
1398   if (NextNonComment->isMemberAccess()) {
1399     if (CurrentState.CallContinuation == 0)
1400       return ContinuationIndent;
1401     return CurrentState.CallContinuation;
1402   }
1403   if (CurrentState.QuestionColumn != 0 &&
1404       ((NextNonComment->is(tok::colon) &&
1405         NextNonComment->is(TT_ConditionalExpr)) ||
1406        Previous.is(TT_ConditionalExpr))) {
1407     if (((NextNonComment->is(tok::colon) && NextNonComment->Next &&
1408           !NextNonComment->Next->FakeLParens.empty() &&
1409           NextNonComment->Next->FakeLParens.back() == prec::Conditional) ||
1410          (Previous.is(tok::colon) && !Current.FakeLParens.empty() &&
1411           Current.FakeLParens.back() == prec::Conditional)) &&
1412         !CurrentState.IsWrappedConditional) {
1413       // NOTE: we may tweak this slightly:
1414       //    * not remove the 'lead' ContinuationIndentWidth
1415       //    * always un-indent by the operator when
1416       //    BreakBeforeTernaryOperators=true
1417       unsigned Indent = CurrentState.Indent;
1418       if (Style.AlignOperands != FormatStyle::OAS_DontAlign)
1419         Indent -= Style.ContinuationIndentWidth;
1420       if (Style.BreakBeforeTernaryOperators && CurrentState.UnindentOperator)
1421         Indent -= 2;
1422       return Indent;
1423     }
1424     return CurrentState.QuestionColumn;
1425   }
1426   if (Previous.is(tok::comma) && CurrentState.VariablePos != 0)
1427     return CurrentState.VariablePos;
1428   if (Current.is(TT_RequiresClause)) {
1429     if (Style.IndentRequiresClause)
1430       return CurrentState.Indent + Style.IndentWidth;
1431     switch (Style.RequiresClausePosition) {
1432     case FormatStyle::RCPS_OwnLine:
1433     case FormatStyle::RCPS_WithFollowing:
1434     case FormatStyle::RCPS_OwnLineWithBrace:
1435       return CurrentState.Indent;
1436     default:
1437       break;
1438     }
1439   }
1440   if (NextNonComment->isOneOf(TT_CtorInitializerColon, TT_InheritanceColon,
1441                               TT_InheritanceComma)) {
1442     return State.FirstIndent + Style.ConstructorInitializerIndentWidth;
1443   }
1444   if ((PreviousNonComment &&
1445        (PreviousNonComment->ClosesTemplateDeclaration ||
1446         PreviousNonComment->ClosesRequiresClause ||
1447         (PreviousNonComment->is(TT_AttributeMacro) &&
1448          Current.isNot(tok::l_paren)) ||
1449         PreviousNonComment->isOneOf(
1450             TT_AttributeRParen, TT_AttributeSquare, TT_FunctionAnnotationRParen,
1451             TT_JavaAnnotation, TT_LeadingJavaAnnotation))) ||
1452       (!Style.IndentWrappedFunctionNames &&
1453        NextNonComment->isOneOf(tok::kw_operator, TT_FunctionDeclarationName))) {
1454     return std::max(CurrentState.LastSpace, CurrentState.Indent);
1455   }
1456   if (NextNonComment->is(TT_SelectorName)) {
1457     if (!CurrentState.ObjCSelectorNameFound) {
1458       unsigned MinIndent = CurrentState.Indent;
1459       if (shouldIndentWrappedSelectorName(Style, State.Line->Type)) {
1460         MinIndent = std::max(MinIndent,
1461                              State.FirstIndent + Style.ContinuationIndentWidth);
1462       }
1463       // If LongestObjCSelectorName is 0, we are indenting the first
1464       // part of an ObjC selector (or a selector component which is
1465       // not colon-aligned due to block formatting).
1466       //
1467       // Otherwise, we are indenting a subsequent part of an ObjC
1468       // selector which should be colon-aligned to the longest
1469       // component of the ObjC selector.
1470       //
1471       // In either case, we want to respect Style.IndentWrappedFunctionNames.
1472       return MinIndent +
1473              std::max(NextNonComment->LongestObjCSelectorName,
1474                       NextNonComment->ColumnWidth) -
1475              NextNonComment->ColumnWidth;
1476     }
1477     if (!CurrentState.AlignColons)
1478       return CurrentState.Indent;
1479     if (CurrentState.ColonPos > NextNonComment->ColumnWidth)
1480       return CurrentState.ColonPos - NextNonComment->ColumnWidth;
1481     return CurrentState.Indent;
1482   }
1483   if (NextNonComment->is(tok::colon) && NextNonComment->is(TT_ObjCMethodExpr))
1484     return CurrentState.ColonPos;
1485   if (NextNonComment->is(TT_ArraySubscriptLSquare)) {
1486     if (CurrentState.StartOfArraySubscripts != 0) {
1487       return CurrentState.StartOfArraySubscripts;
1488     } else if (Style.isCSharp()) { // C# allows `["key"] = value` inside object
1489                                    // initializers.
1490       return CurrentState.Indent;
1491     }
1492     return ContinuationIndent;
1493   }
1494 
1495   // OpenMP clauses want to get additional indentation when they are pushed onto
1496   // the next line.
1497   if (State.Line->InPragmaDirective) {
1498     FormatToken *PragmaType = State.Line->First->Next->Next;
1499     if (PragmaType && PragmaType->TokenText == "omp")
1500       return CurrentState.Indent + Style.ContinuationIndentWidth;
1501   }
1502 
1503   // This ensure that we correctly format ObjC methods calls without inputs,
1504   // i.e. where the last element isn't selector like: [callee method];
1505   if (NextNonComment->is(tok::identifier) && NextNonComment->FakeRParens == 0 &&
1506       NextNonComment->Next && NextNonComment->Next->is(TT_ObjCMethodExpr)) {
1507     return CurrentState.Indent;
1508   }
1509 
1510   if (NextNonComment->isOneOf(TT_StartOfName, TT_PointerOrReference) ||
1511       Previous.isOneOf(tok::coloncolon, tok::equal, TT_JsTypeColon)) {
1512     return ContinuationIndent;
1513   }
1514   if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
1515       PreviousNonComment->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral)) {
1516     return ContinuationIndent;
1517   }
1518   if (NextNonComment->is(TT_CtorInitializerComma))
1519     return CurrentState.Indent;
1520   if (PreviousNonComment && PreviousNonComment->is(TT_CtorInitializerColon) &&
1521       Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon) {
1522     return CurrentState.Indent;
1523   }
1524   if (PreviousNonComment && PreviousNonComment->is(TT_InheritanceColon) &&
1525       Style.BreakInheritanceList == FormatStyle::BILS_AfterColon) {
1526     return CurrentState.Indent;
1527   }
1528   if (Previous.is(tok::r_paren) &&
1529       Previous.isNot(TT_TableGenDAGArgOperatorToBreak) &&
1530       !Current.isBinaryOperator() &&
1531       !Current.isOneOf(tok::colon, tok::comment)) {
1532     return ContinuationIndent;
1533   }
1534   if (Current.is(TT_ProtoExtensionLSquare))
1535     return CurrentState.Indent;
1536   if (Current.isBinaryOperator() && CurrentState.UnindentOperator) {
1537     return CurrentState.Indent - Current.Tok.getLength() -
1538            Current.SpacesRequiredBefore;
1539   }
1540   if (Current.is(tok::comment) && NextNonComment->isBinaryOperator() &&
1541       CurrentState.UnindentOperator) {
1542     return CurrentState.Indent - NextNonComment->Tok.getLength() -
1543            NextNonComment->SpacesRequiredBefore;
1544   }
1545   if (CurrentState.Indent == State.FirstIndent && PreviousNonComment &&
1546       !PreviousNonComment->isOneOf(tok::r_brace, TT_CtorInitializerComma)) {
1547     // Ensure that we fall back to the continuation indent width instead of
1548     // just flushing continuations left.
1549     return CurrentState.Indent + Style.ContinuationIndentWidth;
1550   }
1551   return CurrentState.Indent;
1552 }
1553 
1554 static bool hasNestedBlockInlined(const FormatToken *Previous,
1555                                   const FormatToken &Current,
1556                                   const FormatStyle &Style) {
1557   if (Previous->isNot(tok::l_paren))
1558     return true;
1559   if (Previous->ParameterCount > 1)
1560     return true;
1561 
1562   // Also a nested block if contains a lambda inside function with 1 parameter.
1563   return Style.BraceWrapping.BeforeLambdaBody && Current.is(TT_LambdaLSquare);
1564 }
1565 
1566 unsigned ContinuationIndenter::moveStateToNextToken(LineState &State,
1567                                                     bool DryRun, bool Newline) {
1568   assert(State.Stack.size());
1569   const FormatToken &Current = *State.NextToken;
1570   auto &CurrentState = State.Stack.back();
1571 
1572   if (Current.is(TT_CSharpGenericTypeConstraint))
1573     CurrentState.IsCSharpGenericTypeConstraint = true;
1574   if (Current.isOneOf(tok::comma, TT_BinaryOperator))
1575     CurrentState.NoLineBreakInOperand = false;
1576   if (Current.isOneOf(TT_InheritanceColon, TT_CSharpGenericTypeConstraintColon))
1577     CurrentState.AvoidBinPacking = true;
1578   if (Current.is(tok::lessless) && Current.isNot(TT_OverloadedOperator)) {
1579     if (CurrentState.FirstLessLess == 0)
1580       CurrentState.FirstLessLess = State.Column;
1581     else
1582       CurrentState.LastOperatorWrapped = Newline;
1583   }
1584   if (Current.is(TT_BinaryOperator) && Current.isNot(tok::lessless))
1585     CurrentState.LastOperatorWrapped = Newline;
1586   if (Current.is(TT_ConditionalExpr) && Current.Previous &&
1587       Current.Previous->isNot(TT_ConditionalExpr)) {
1588     CurrentState.LastOperatorWrapped = Newline;
1589   }
1590   if (Current.is(TT_ArraySubscriptLSquare) &&
1591       CurrentState.StartOfArraySubscripts == 0) {
1592     CurrentState.StartOfArraySubscripts = State.Column;
1593   }
1594 
1595   auto IsWrappedConditional = [](const FormatToken &Tok) {
1596     if (!(Tok.is(TT_ConditionalExpr) && Tok.is(tok::question)))
1597       return false;
1598     if (Tok.MustBreakBefore)
1599       return true;
1600 
1601     const FormatToken *Next = Tok.getNextNonComment();
1602     return Next && Next->MustBreakBefore;
1603   };
1604   if (IsWrappedConditional(Current))
1605     CurrentState.IsWrappedConditional = true;
1606   if (Style.BreakBeforeTernaryOperators && Current.is(tok::question))
1607     CurrentState.QuestionColumn = State.Column;
1608   if (!Style.BreakBeforeTernaryOperators && Current.isNot(tok::colon)) {
1609     const FormatToken *Previous = Current.Previous;
1610     while (Previous && Previous->isTrailingComment())
1611       Previous = Previous->Previous;
1612     if (Previous && Previous->is(tok::question))
1613       CurrentState.QuestionColumn = State.Column;
1614   }
1615   if (!Current.opensScope() && !Current.closesScope() &&
1616       Current.isNot(TT_PointerOrReference)) {
1617     State.LowestLevelOnLine =
1618         std::min(State.LowestLevelOnLine, Current.NestingLevel);
1619   }
1620   if (Current.isMemberAccess())
1621     CurrentState.StartOfFunctionCall = !Current.NextOperator ? 0 : State.Column;
1622   if (Current.is(TT_SelectorName))
1623     CurrentState.ObjCSelectorNameFound = true;
1624   if (Current.is(TT_CtorInitializerColon) &&
1625       Style.BreakConstructorInitializers != FormatStyle::BCIS_AfterColon) {
1626     // Indent 2 from the column, so:
1627     // SomeClass::SomeClass()
1628     //     : First(...), ...
1629     //       Next(...)
1630     //       ^ line up here.
1631     CurrentState.Indent = State.Column + (Style.BreakConstructorInitializers ==
1632                                                   FormatStyle::BCIS_BeforeComma
1633                                               ? 0
1634                                               : 2);
1635     CurrentState.NestedBlockIndent = CurrentState.Indent;
1636     if (Style.PackConstructorInitializers > FormatStyle::PCIS_BinPack) {
1637       CurrentState.AvoidBinPacking = true;
1638       CurrentState.BreakBeforeParameter =
1639           Style.ColumnLimit > 0 &&
1640           Style.PackConstructorInitializers != FormatStyle::PCIS_NextLine &&
1641           Style.PackConstructorInitializers != FormatStyle::PCIS_NextLineOnly;
1642     } else {
1643       CurrentState.BreakBeforeParameter = false;
1644     }
1645   }
1646   if (Current.is(TT_CtorInitializerColon) &&
1647       Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon) {
1648     CurrentState.Indent =
1649         State.FirstIndent + Style.ConstructorInitializerIndentWidth;
1650     CurrentState.NestedBlockIndent = CurrentState.Indent;
1651     if (Style.PackConstructorInitializers > FormatStyle::PCIS_BinPack)
1652       CurrentState.AvoidBinPacking = true;
1653     else
1654       CurrentState.BreakBeforeParameter = false;
1655   }
1656   if (Current.is(TT_InheritanceColon)) {
1657     CurrentState.Indent =
1658         State.FirstIndent + Style.ConstructorInitializerIndentWidth;
1659   }
1660   if (Current.isOneOf(TT_BinaryOperator, TT_ConditionalExpr) && Newline)
1661     CurrentState.NestedBlockIndent = State.Column + Current.ColumnWidth + 1;
1662   if (Current.isOneOf(TT_LambdaLSquare, TT_LambdaArrow))
1663     CurrentState.LastSpace = State.Column;
1664   if (Current.is(TT_RequiresExpression) &&
1665       Style.RequiresExpressionIndentation == FormatStyle::REI_Keyword) {
1666     CurrentState.NestedBlockIndent = State.Column;
1667   }
1668 
1669   // Insert scopes created by fake parenthesis.
1670   const FormatToken *Previous = Current.getPreviousNonComment();
1671 
1672   // Add special behavior to support a format commonly used for JavaScript
1673   // closures:
1674   //   SomeFunction(function() {
1675   //     foo();
1676   //     bar();
1677   //   }, a, b, c);
1678   if (Current.isNot(tok::comment) && !Current.ClosesRequiresClause &&
1679       Previous && Previous->isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) &&
1680       Previous->isNot(TT_DictLiteral) && State.Stack.size() > 1 &&
1681       !CurrentState.HasMultipleNestedBlocks) {
1682     if (State.Stack[State.Stack.size() - 2].NestedBlockInlined && Newline)
1683       for (ParenState &PState : llvm::drop_end(State.Stack))
1684         PState.NoLineBreak = true;
1685     State.Stack[State.Stack.size() - 2].NestedBlockInlined = false;
1686   }
1687   if (Previous && (Previous->isOneOf(TT_BinaryOperator, TT_ConditionalExpr) ||
1688                    (Previous->isOneOf(tok::l_paren, tok::comma, tok::colon) &&
1689                     !Previous->isOneOf(TT_DictLiteral, TT_ObjCMethodExpr)))) {
1690     CurrentState.NestedBlockInlined =
1691         !Newline && hasNestedBlockInlined(Previous, Current, Style);
1692   }
1693 
1694   moveStatePastFakeLParens(State, Newline);
1695   moveStatePastScopeCloser(State);
1696   // Do not use CurrentState here, since the two functions before may change the
1697   // Stack.
1698   bool AllowBreak = !State.Stack.back().NoLineBreak &&
1699                     !State.Stack.back().NoLineBreakInOperand;
1700   moveStatePastScopeOpener(State, Newline);
1701   moveStatePastFakeRParens(State);
1702 
1703   if (Current.is(TT_ObjCStringLiteral) && State.StartOfStringLiteral == 0)
1704     State.StartOfStringLiteral = State.Column + 1;
1705   if (Current.is(TT_CSharpStringLiteral) && State.StartOfStringLiteral == 0) {
1706     State.StartOfStringLiteral = State.Column + 1;
1707   } else if (Current.is(TT_TableGenMultiLineString) &&
1708              State.StartOfStringLiteral == 0) {
1709     State.StartOfStringLiteral = State.Column + 1;
1710   } else if (Current.isStringLiteral() && State.StartOfStringLiteral == 0) {
1711     State.StartOfStringLiteral = State.Column;
1712   } else if (!Current.isOneOf(tok::comment, tok::identifier, tok::hash) &&
1713              !Current.isStringLiteral()) {
1714     State.StartOfStringLiteral = 0;
1715   }
1716 
1717   State.Column += Current.ColumnWidth;
1718   State.NextToken = State.NextToken->Next;
1719   // Verilog case labels are on the same unwrapped lines as the statements that
1720   // follow. TokenAnnotator identifies them and sets MustBreakBefore.
1721   // Indentation is taken care of here. A case label can only have 1 statement
1722   // in Verilog, so we don't have to worry about lines that follow.
1723   if (Style.isVerilog() && State.NextToken &&
1724       State.NextToken->MustBreakBefore &&
1725       Keywords.isVerilogEndOfLabel(Current)) {
1726     State.FirstIndent += Style.IndentWidth;
1727     CurrentState.Indent = State.FirstIndent;
1728   }
1729 
1730   unsigned Penalty =
1731       handleEndOfLine(Current, State, DryRun, AllowBreak, Newline);
1732 
1733   if (Current.Role)
1734     Current.Role->formatFromToken(State, this, DryRun);
1735   // If the previous has a special role, let it consume tokens as appropriate.
1736   // It is necessary to start at the previous token for the only implemented
1737   // role (comma separated list). That way, the decision whether or not to break
1738   // after the "{" is already done and both options are tried and evaluated.
1739   // FIXME: This is ugly, find a better way.
1740   if (Previous && Previous->Role)
1741     Penalty += Previous->Role->formatAfterToken(State, this, DryRun);
1742 
1743   return Penalty;
1744 }
1745 
1746 void ContinuationIndenter::moveStatePastFakeLParens(LineState &State,
1747                                                     bool Newline) {
1748   const FormatToken &Current = *State.NextToken;
1749   if (Current.FakeLParens.empty())
1750     return;
1751 
1752   const FormatToken *Previous = Current.getPreviousNonComment();
1753 
1754   // Don't add extra indentation for the first fake parenthesis after
1755   // 'return', assignments, opening <({[, or requires clauses. The indentation
1756   // for these cases is special cased.
1757   bool SkipFirstExtraIndent =
1758       Previous &&
1759       (Previous->opensScope() ||
1760        Previous->isOneOf(tok::semi, tok::kw_return, TT_RequiresClause) ||
1761        (Previous->getPrecedence() == prec::Assignment &&
1762         Style.AlignOperands != FormatStyle::OAS_DontAlign) ||
1763        Previous->is(TT_ObjCMethodExpr));
1764   for (const auto &PrecedenceLevel : llvm::reverse(Current.FakeLParens)) {
1765     const auto &CurrentState = State.Stack.back();
1766     ParenState NewParenState = CurrentState;
1767     NewParenState.Tok = nullptr;
1768     NewParenState.ContainsLineBreak = false;
1769     NewParenState.LastOperatorWrapped = true;
1770     NewParenState.IsChainedConditional = false;
1771     NewParenState.IsWrappedConditional = false;
1772     NewParenState.UnindentOperator = false;
1773     NewParenState.NoLineBreak =
1774         NewParenState.NoLineBreak || CurrentState.NoLineBreakInOperand;
1775 
1776     // Don't propagate AvoidBinPacking into subexpressions of arg/param lists.
1777     if (PrecedenceLevel > prec::Comma)
1778       NewParenState.AvoidBinPacking = false;
1779 
1780     // Indent from 'LastSpace' unless these are fake parentheses encapsulating
1781     // a builder type call after 'return' or, if the alignment after opening
1782     // brackets is disabled.
1783     if (!Current.isTrailingComment() &&
1784         (Style.AlignOperands != FormatStyle::OAS_DontAlign ||
1785          PrecedenceLevel < prec::Assignment) &&
1786         (!Previous || Previous->isNot(tok::kw_return) ||
1787          (Style.Language != FormatStyle::LK_Java && PrecedenceLevel > 0)) &&
1788         (Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign ||
1789          PrecedenceLevel > prec::Comma || Current.NestingLevel == 0) &&
1790         (!Style.isTableGen() ||
1791          (Previous && Previous->isOneOf(TT_TableGenDAGArgListComma,
1792                                         TT_TableGenDAGArgListCommaToBreak)))) {
1793       NewParenState.Indent = std::max(
1794           std::max(State.Column, NewParenState.Indent), CurrentState.LastSpace);
1795     }
1796 
1797     // Special case for generic selection expressions, its comma-separated
1798     // expressions are not aligned to the opening paren like regular calls, but
1799     // rather continuation-indented relative to the _Generic keyword.
1800     if (Previous && Previous->endsSequence(tok::l_paren, tok::kw__Generic) &&
1801         State.Stack.size() > 1) {
1802       NewParenState.Indent = State.Stack[State.Stack.size() - 2].Indent +
1803                              Style.ContinuationIndentWidth;
1804     }
1805 
1806     if ((shouldUnindentNextOperator(Current) ||
1807          (Previous &&
1808           (PrecedenceLevel == prec::Conditional &&
1809            Previous->is(tok::question) && Previous->is(TT_ConditionalExpr)))) &&
1810         !Newline) {
1811       // If BreakBeforeBinaryOperators is set, un-indent a bit to account for
1812       // the operator and keep the operands aligned.
1813       if (Style.AlignOperands == FormatStyle::OAS_AlignAfterOperator)
1814         NewParenState.UnindentOperator = true;
1815       // Mark indentation as alignment if the expression is aligned.
1816       if (Style.AlignOperands != FormatStyle::OAS_DontAlign)
1817         NewParenState.IsAligned = true;
1818     }
1819 
1820     // Do not indent relative to the fake parentheses inserted for "." or "->".
1821     // This is a special case to make the following to statements consistent:
1822     //   OuterFunction(InnerFunctionCall( // break
1823     //       ParameterToInnerFunction));
1824     //   OuterFunction(SomeObject.InnerFunctionCall( // break
1825     //       ParameterToInnerFunction));
1826     if (PrecedenceLevel > prec::Unknown)
1827       NewParenState.LastSpace = std::max(NewParenState.LastSpace, State.Column);
1828     if (PrecedenceLevel != prec::Conditional &&
1829         Current.isNot(TT_UnaryOperator) &&
1830         Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign) {
1831       NewParenState.StartOfFunctionCall = State.Column;
1832     }
1833 
1834     // Indent conditional expressions, unless they are chained "else-if"
1835     // conditionals. Never indent expression where the 'operator' is ',', ';' or
1836     // an assignment (i.e. *I <= prec::Assignment) as those have different
1837     // indentation rules. Indent other expression, unless the indentation needs
1838     // to be skipped.
1839     if (PrecedenceLevel == prec::Conditional && Previous &&
1840         Previous->is(tok::colon) && Previous->is(TT_ConditionalExpr) &&
1841         &PrecedenceLevel == &Current.FakeLParens.back() &&
1842         !CurrentState.IsWrappedConditional) {
1843       NewParenState.IsChainedConditional = true;
1844       NewParenState.UnindentOperator = State.Stack.back().UnindentOperator;
1845     } else if (PrecedenceLevel == prec::Conditional ||
1846                (!SkipFirstExtraIndent && PrecedenceLevel > prec::Assignment &&
1847                 !Current.isTrailingComment())) {
1848       NewParenState.Indent += Style.ContinuationIndentWidth;
1849     }
1850     if ((Previous && !Previous->opensScope()) || PrecedenceLevel != prec::Comma)
1851       NewParenState.BreakBeforeParameter = false;
1852     State.Stack.push_back(NewParenState);
1853     SkipFirstExtraIndent = false;
1854   }
1855 }
1856 
1857 void ContinuationIndenter::moveStatePastFakeRParens(LineState &State) {
1858   for (unsigned i = 0, e = State.NextToken->FakeRParens; i != e; ++i) {
1859     unsigned VariablePos = State.Stack.back().VariablePos;
1860     if (State.Stack.size() == 1) {
1861       // Do not pop the last element.
1862       break;
1863     }
1864     State.Stack.pop_back();
1865     State.Stack.back().VariablePos = VariablePos;
1866   }
1867 
1868   if (State.NextToken->ClosesRequiresClause && Style.IndentRequiresClause) {
1869     // Remove the indentation of the requires clauses (which is not in Indent,
1870     // but in LastSpace).
1871     State.Stack.back().LastSpace -= Style.IndentWidth;
1872   }
1873 }
1874 
1875 void ContinuationIndenter::moveStatePastScopeOpener(LineState &State,
1876                                                     bool Newline) {
1877   const FormatToken &Current = *State.NextToken;
1878   if (!Current.opensScope())
1879     return;
1880 
1881   const auto &CurrentState = State.Stack.back();
1882 
1883   // Don't allow '<' or '(' in C# generic type constraints to start new scopes.
1884   if (Current.isOneOf(tok::less, tok::l_paren) &&
1885       CurrentState.IsCSharpGenericTypeConstraint) {
1886     return;
1887   }
1888 
1889   if (Current.MatchingParen && Current.is(BK_Block)) {
1890     moveStateToNewBlock(State, Newline);
1891     return;
1892   }
1893 
1894   unsigned NewIndent;
1895   unsigned LastSpace = CurrentState.LastSpace;
1896   bool AvoidBinPacking;
1897   bool BreakBeforeParameter = false;
1898   unsigned NestedBlockIndent = std::max(CurrentState.StartOfFunctionCall,
1899                                         CurrentState.NestedBlockIndent);
1900   if (Current.isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) ||
1901       opensProtoMessageField(Current, Style)) {
1902     if (Current.opensBlockOrBlockTypeList(Style)) {
1903       NewIndent = Style.IndentWidth +
1904                   std::min(State.Column, CurrentState.NestedBlockIndent);
1905     } else if (Current.is(tok::l_brace)) {
1906       NewIndent =
1907           CurrentState.LastSpace + Style.BracedInitializerIndentWidth.value_or(
1908                                        Style.ContinuationIndentWidth);
1909     } else {
1910       NewIndent = CurrentState.LastSpace + Style.ContinuationIndentWidth;
1911     }
1912     const FormatToken *NextNonComment = Current.getNextNonComment();
1913     bool EndsInComma = Current.MatchingParen &&
1914                        Current.MatchingParen->Previous &&
1915                        Current.MatchingParen->Previous->is(tok::comma);
1916     AvoidBinPacking = EndsInComma || Current.is(TT_DictLiteral) ||
1917                       Style.isProto() || !Style.BinPackArguments ||
1918                       (NextNonComment && NextNonComment->isOneOf(
1919                                              TT_DesignatedInitializerPeriod,
1920                                              TT_DesignatedInitializerLSquare));
1921     BreakBeforeParameter = EndsInComma;
1922     if (Current.ParameterCount > 1)
1923       NestedBlockIndent = std::max(NestedBlockIndent, State.Column + 1);
1924   } else {
1925     NewIndent =
1926         Style.ContinuationIndentWidth +
1927         std::max(CurrentState.LastSpace, CurrentState.StartOfFunctionCall);
1928 
1929     if (Style.isTableGen() && Current.is(TT_TableGenDAGArgOpenerToBreak) &&
1930         Style.TableGenBreakInsideDAGArg == FormatStyle::DAS_BreakElements) {
1931       // For the case the next token is a TableGen DAGArg operator identifier
1932       // that is not marked to have a line break after it.
1933       // In this case the option DAS_BreakElements requires to align the
1934       // DAGArg elements to the operator.
1935       const FormatToken *Next = Current.Next;
1936       if (Next && Next->is(TT_TableGenDAGArgOperatorID))
1937         NewIndent = State.Column + Next->TokenText.size() + 2;
1938     }
1939 
1940     // Ensure that different different brackets force relative alignment, e.g.:
1941     // void SomeFunction(vector<  // break
1942     //                       int> v);
1943     // FIXME: We likely want to do this for more combinations of brackets.
1944     if (Current.is(tok::less) && Current.ParentBracket == tok::l_paren) {
1945       NewIndent = std::max(NewIndent, CurrentState.Indent);
1946       LastSpace = std::max(LastSpace, CurrentState.Indent);
1947     }
1948 
1949     bool EndsInComma =
1950         Current.MatchingParen &&
1951         Current.MatchingParen->getPreviousNonComment() &&
1952         Current.MatchingParen->getPreviousNonComment()->is(tok::comma);
1953 
1954     // If ObjCBinPackProtocolList is unspecified, fall back to BinPackParameters
1955     // for backwards compatibility.
1956     bool ObjCBinPackProtocolList =
1957         (Style.ObjCBinPackProtocolList == FormatStyle::BPS_Auto &&
1958          Style.BinPackParameters == FormatStyle::BPPS_BinPack) ||
1959         Style.ObjCBinPackProtocolList == FormatStyle::BPS_Always;
1960 
1961     bool BinPackDeclaration =
1962         (State.Line->Type != LT_ObjCDecl &&
1963          Style.BinPackParameters == FormatStyle::BPPS_BinPack) ||
1964         (State.Line->Type == LT_ObjCDecl && ObjCBinPackProtocolList);
1965 
1966     bool GenericSelection =
1967         Current.getPreviousNonComment() &&
1968         Current.getPreviousNonComment()->is(tok::kw__Generic);
1969 
1970     AvoidBinPacking =
1971         (CurrentState.IsCSharpGenericTypeConstraint) || GenericSelection ||
1972         (Style.isJavaScript() && EndsInComma) ||
1973         (State.Line->MustBeDeclaration && !BinPackDeclaration) ||
1974         (!State.Line->MustBeDeclaration && !Style.BinPackArguments) ||
1975         (Style.ExperimentalAutoDetectBinPacking &&
1976          (Current.is(PPK_OnePerLine) ||
1977           (!BinPackInconclusiveFunctions && Current.is(PPK_Inconclusive))));
1978 
1979     if (Current.is(TT_ObjCMethodExpr) && Current.MatchingParen &&
1980         Style.ObjCBreakBeforeNestedBlockParam) {
1981       if (Style.ColumnLimit) {
1982         // If this '[' opens an ObjC call, determine whether all parameters fit
1983         // into one line and put one per line if they don't.
1984         if (getLengthToMatchingParen(Current, State.Stack) + State.Column >
1985             getColumnLimit(State)) {
1986           BreakBeforeParameter = true;
1987         }
1988       } else {
1989         // For ColumnLimit = 0, we have to figure out whether there is or has to
1990         // be a line break within this call.
1991         for (const FormatToken *Tok = &Current;
1992              Tok && Tok != Current.MatchingParen; Tok = Tok->Next) {
1993           if (Tok->MustBreakBefore ||
1994               (Tok->CanBreakBefore && Tok->NewlinesBefore > 0)) {
1995             BreakBeforeParameter = true;
1996             break;
1997           }
1998         }
1999       }
2000     }
2001 
2002     if (Style.isJavaScript() && EndsInComma)
2003       BreakBeforeParameter = true;
2004   }
2005   // Generally inherit NoLineBreak from the current scope to nested scope.
2006   // However, don't do this for non-empty nested blocks, dict literals and
2007   // array literals as these follow different indentation rules.
2008   bool NoLineBreak =
2009       Current.Children.empty() &&
2010       !Current.isOneOf(TT_DictLiteral, TT_ArrayInitializerLSquare) &&
2011       (CurrentState.NoLineBreak || CurrentState.NoLineBreakInOperand ||
2012        (Current.is(TT_TemplateOpener) &&
2013         CurrentState.ContainsUnwrappedBuilder));
2014   State.Stack.push_back(
2015       ParenState(&Current, NewIndent, LastSpace, AvoidBinPacking, NoLineBreak));
2016   auto &NewState = State.Stack.back();
2017   NewState.NestedBlockIndent = NestedBlockIndent;
2018   NewState.BreakBeforeParameter = BreakBeforeParameter;
2019   NewState.HasMultipleNestedBlocks = (Current.BlockParameterCount > 1);
2020 
2021   if (Style.BraceWrapping.BeforeLambdaBody && Current.Next &&
2022       Current.is(tok::l_paren)) {
2023     // Search for any parameter that is a lambda.
2024     FormatToken const *next = Current.Next;
2025     while (next) {
2026       if (next->is(TT_LambdaLSquare)) {
2027         NewState.HasMultipleNestedBlocks = true;
2028         break;
2029       }
2030       next = next->Next;
2031     }
2032   }
2033 
2034   NewState.IsInsideObjCArrayLiteral = Current.is(TT_ArrayInitializerLSquare) &&
2035                                       Current.Previous &&
2036                                       Current.Previous->is(tok::at);
2037 }
2038 
2039 void ContinuationIndenter::moveStatePastScopeCloser(LineState &State) {
2040   const FormatToken &Current = *State.NextToken;
2041   if (!Current.closesScope())
2042     return;
2043 
2044   // If we encounter a closing ), ], } or >, we can remove a level from our
2045   // stacks.
2046   if (State.Stack.size() > 1 &&
2047       (Current.isOneOf(tok::r_paren, tok::r_square, TT_TemplateString) ||
2048        (Current.is(tok::r_brace) && State.NextToken != State.Line->First) ||
2049        State.NextToken->is(TT_TemplateCloser) ||
2050        State.NextToken->is(TT_TableGenListCloser) ||
2051        (Current.is(tok::greater) && Current.is(TT_DictLiteral)))) {
2052     State.Stack.pop_back();
2053   }
2054 
2055   auto &CurrentState = State.Stack.back();
2056 
2057   // Reevaluate whether ObjC message arguments fit into one line.
2058   // If a receiver spans multiple lines, e.g.:
2059   //   [[object block:^{
2060   //     return 42;
2061   //   }] a:42 b:42];
2062   // BreakBeforeParameter is calculated based on an incorrect assumption
2063   // (it is checked whether the whole expression fits into one line without
2064   // considering a line break inside a message receiver).
2065   // We check whether arguments fit after receiver scope closer (into the same
2066   // line).
2067   if (CurrentState.BreakBeforeParameter && Current.MatchingParen &&
2068       Current.MatchingParen->Previous) {
2069     const FormatToken &CurrentScopeOpener = *Current.MatchingParen->Previous;
2070     if (CurrentScopeOpener.is(TT_ObjCMethodExpr) &&
2071         CurrentScopeOpener.MatchingParen) {
2072       int NecessarySpaceInLine =
2073           getLengthToMatchingParen(CurrentScopeOpener, State.Stack) +
2074           CurrentScopeOpener.TotalLength - Current.TotalLength - 1;
2075       if (State.Column + Current.ColumnWidth + NecessarySpaceInLine <=
2076           Style.ColumnLimit) {
2077         CurrentState.BreakBeforeParameter = false;
2078       }
2079     }
2080   }
2081 
2082   if (Current.is(tok::r_square)) {
2083     // If this ends the array subscript expr, reset the corresponding value.
2084     const FormatToken *NextNonComment = Current.getNextNonComment();
2085     if (NextNonComment && NextNonComment->isNot(tok::l_square))
2086       CurrentState.StartOfArraySubscripts = 0;
2087   }
2088 }
2089 
2090 void ContinuationIndenter::moveStateToNewBlock(LineState &State, bool NewLine) {
2091   if (Style.LambdaBodyIndentation == FormatStyle::LBI_OuterScope &&
2092       State.NextToken->is(TT_LambdaLBrace) &&
2093       !State.Line->MightBeFunctionDecl) {
2094     State.Stack.back().NestedBlockIndent = State.FirstIndent;
2095   }
2096   unsigned NestedBlockIndent = State.Stack.back().NestedBlockIndent;
2097   // ObjC block sometimes follow special indentation rules.
2098   unsigned NewIndent =
2099       NestedBlockIndent + (State.NextToken->is(TT_ObjCBlockLBrace)
2100                                ? Style.ObjCBlockIndentWidth
2101                                : Style.IndentWidth);
2102 
2103   // Even when wrapping before lambda body, the left brace can still be added to
2104   // the same line. This occurs when checking whether the whole lambda body can
2105   // go on a single line. In this case we have to make sure there are no line
2106   // breaks in the body, otherwise we could just end up with a regular lambda
2107   // body without the brace wrapped.
2108   bool NoLineBreak = Style.BraceWrapping.BeforeLambdaBody && !NewLine &&
2109                      State.NextToken->is(TT_LambdaLBrace);
2110 
2111   State.Stack.push_back(ParenState(State.NextToken, NewIndent,
2112                                    State.Stack.back().LastSpace,
2113                                    /*AvoidBinPacking=*/true, NoLineBreak));
2114   State.Stack.back().NestedBlockIndent = NestedBlockIndent;
2115   State.Stack.back().BreakBeforeParameter = true;
2116 }
2117 
2118 static unsigned getLastLineEndColumn(StringRef Text, unsigned StartColumn,
2119                                      unsigned TabWidth,
2120                                      encoding::Encoding Encoding) {
2121   size_t LastNewlinePos = Text.find_last_of("\n");
2122   if (LastNewlinePos == StringRef::npos) {
2123     return StartColumn +
2124            encoding::columnWidthWithTabs(Text, StartColumn, TabWidth, Encoding);
2125   } else {
2126     return encoding::columnWidthWithTabs(Text.substr(LastNewlinePos),
2127                                          /*StartColumn=*/0, TabWidth, Encoding);
2128   }
2129 }
2130 
2131 unsigned ContinuationIndenter::reformatRawStringLiteral(
2132     const FormatToken &Current, LineState &State,
2133     const FormatStyle &RawStringStyle, bool DryRun, bool Newline) {
2134   unsigned StartColumn = State.Column - Current.ColumnWidth;
2135   StringRef OldDelimiter = *getRawStringDelimiter(Current.TokenText);
2136   StringRef NewDelimiter =
2137       getCanonicalRawStringDelimiter(Style, RawStringStyle.Language);
2138   if (NewDelimiter.empty())
2139     NewDelimiter = OldDelimiter;
2140   // The text of a raw string is between the leading 'R"delimiter(' and the
2141   // trailing 'delimiter)"'.
2142   unsigned OldPrefixSize = 3 + OldDelimiter.size();
2143   unsigned OldSuffixSize = 2 + OldDelimiter.size();
2144   // We create a virtual text environment which expects a null-terminated
2145   // string, so we cannot use StringRef.
2146   std::string RawText = std::string(
2147       Current.TokenText.substr(OldPrefixSize).drop_back(OldSuffixSize));
2148   if (NewDelimiter != OldDelimiter) {
2149     // Don't update to the canonical delimiter 'deli' if ')deli"' occurs in the
2150     // raw string.
2151     std::string CanonicalDelimiterSuffix = (")" + NewDelimiter + "\"").str();
2152     if (StringRef(RawText).contains(CanonicalDelimiterSuffix))
2153       NewDelimiter = OldDelimiter;
2154   }
2155 
2156   unsigned NewPrefixSize = 3 + NewDelimiter.size();
2157   unsigned NewSuffixSize = 2 + NewDelimiter.size();
2158 
2159   // The first start column is the column the raw text starts after formatting.
2160   unsigned FirstStartColumn = StartColumn + NewPrefixSize;
2161 
2162   // The next start column is the intended indentation a line break inside
2163   // the raw string at level 0. It is determined by the following rules:
2164   //   - if the content starts on newline, it is one level more than the current
2165   //     indent, and
2166   //   - if the content does not start on a newline, it is the first start
2167   //     column.
2168   // These rules have the advantage that the formatted content both does not
2169   // violate the rectangle rule and visually flows within the surrounding
2170   // source.
2171   bool ContentStartsOnNewline = Current.TokenText[OldPrefixSize] == '\n';
2172   // If this token is the last parameter (checked by looking if it's followed by
2173   // `)` and is not on a newline, the base the indent off the line's nested
2174   // block indent. Otherwise, base the indent off the arguments indent, so we
2175   // can achieve:
2176   //
2177   // fffffffffff(1, 2, 3, R"pb(
2178   //     key1: 1  #
2179   //     key2: 2)pb");
2180   //
2181   // fffffffffff(1, 2, 3,
2182   //             R"pb(
2183   //               key1: 1  #
2184   //               key2: 2
2185   //             )pb");
2186   //
2187   // fffffffffff(1, 2, 3,
2188   //             R"pb(
2189   //               key1: 1  #
2190   //               key2: 2
2191   //             )pb",
2192   //             5);
2193   unsigned CurrentIndent =
2194       (!Newline && Current.Next && Current.Next->is(tok::r_paren))
2195           ? State.Stack.back().NestedBlockIndent
2196           : State.Stack.back().Indent;
2197   unsigned NextStartColumn = ContentStartsOnNewline
2198                                  ? CurrentIndent + Style.IndentWidth
2199                                  : FirstStartColumn;
2200 
2201   // The last start column is the column the raw string suffix starts if it is
2202   // put on a newline.
2203   // The last start column is the intended indentation of the raw string postfix
2204   // if it is put on a newline. It is determined by the following rules:
2205   //   - if the raw string prefix starts on a newline, it is the column where
2206   //     that raw string prefix starts, and
2207   //   - if the raw string prefix does not start on a newline, it is the current
2208   //     indent.
2209   unsigned LastStartColumn =
2210       Current.NewlinesBefore ? FirstStartColumn - NewPrefixSize : CurrentIndent;
2211 
2212   std::pair<tooling::Replacements, unsigned> Fixes = internal::reformat(
2213       RawStringStyle, RawText, {tooling::Range(0, RawText.size())},
2214       FirstStartColumn, NextStartColumn, LastStartColumn, "<stdin>",
2215       /*Status=*/nullptr);
2216 
2217   auto NewCode = applyAllReplacements(RawText, Fixes.first);
2218   tooling::Replacements NoFixes;
2219   if (!NewCode)
2220     return addMultilineToken(Current, State);
2221   if (!DryRun) {
2222     if (NewDelimiter != OldDelimiter) {
2223       // In 'R"delimiter(...', the delimiter starts 2 characters after the start
2224       // of the token.
2225       SourceLocation PrefixDelimiterStart =
2226           Current.Tok.getLocation().getLocWithOffset(2);
2227       auto PrefixErr = Whitespaces.addReplacement(tooling::Replacement(
2228           SourceMgr, PrefixDelimiterStart, OldDelimiter.size(), NewDelimiter));
2229       if (PrefixErr) {
2230         llvm::errs()
2231             << "Failed to update the prefix delimiter of a raw string: "
2232             << llvm::toString(std::move(PrefixErr)) << "\n";
2233       }
2234       // In 'R"delimiter(...)delimiter"', the suffix delimiter starts at
2235       // position length - 1 - |delimiter|.
2236       SourceLocation SuffixDelimiterStart =
2237           Current.Tok.getLocation().getLocWithOffset(Current.TokenText.size() -
2238                                                      1 - OldDelimiter.size());
2239       auto SuffixErr = Whitespaces.addReplacement(tooling::Replacement(
2240           SourceMgr, SuffixDelimiterStart, OldDelimiter.size(), NewDelimiter));
2241       if (SuffixErr) {
2242         llvm::errs()
2243             << "Failed to update the suffix delimiter of a raw string: "
2244             << llvm::toString(std::move(SuffixErr)) << "\n";
2245       }
2246     }
2247     SourceLocation OriginLoc =
2248         Current.Tok.getLocation().getLocWithOffset(OldPrefixSize);
2249     for (const tooling::Replacement &Fix : Fixes.first) {
2250       auto Err = Whitespaces.addReplacement(tooling::Replacement(
2251           SourceMgr, OriginLoc.getLocWithOffset(Fix.getOffset()),
2252           Fix.getLength(), Fix.getReplacementText()));
2253       if (Err) {
2254         llvm::errs() << "Failed to reformat raw string: "
2255                      << llvm::toString(std::move(Err)) << "\n";
2256       }
2257     }
2258   }
2259   unsigned RawLastLineEndColumn = getLastLineEndColumn(
2260       *NewCode, FirstStartColumn, Style.TabWidth, Encoding);
2261   State.Column = RawLastLineEndColumn + NewSuffixSize;
2262   // Since we're updating the column to after the raw string literal here, we
2263   // have to manually add the penalty for the prefix R"delim( over the column
2264   // limit.
2265   unsigned PrefixExcessCharacters =
2266       StartColumn + NewPrefixSize > Style.ColumnLimit
2267           ? StartColumn + NewPrefixSize - Style.ColumnLimit
2268           : 0;
2269   bool IsMultiline =
2270       ContentStartsOnNewline || (NewCode->find('\n') != std::string::npos);
2271   if (IsMultiline) {
2272     // Break before further function parameters on all levels.
2273     for (ParenState &Paren : State.Stack)
2274       Paren.BreakBeforeParameter = true;
2275   }
2276   return Fixes.second + PrefixExcessCharacters * Style.PenaltyExcessCharacter;
2277 }
2278 
2279 unsigned ContinuationIndenter::addMultilineToken(const FormatToken &Current,
2280                                                  LineState &State) {
2281   // Break before further function parameters on all levels.
2282   for (ParenState &Paren : State.Stack)
2283     Paren.BreakBeforeParameter = true;
2284 
2285   unsigned ColumnsUsed = State.Column;
2286   // We can only affect layout of the first and the last line, so the penalty
2287   // for all other lines is constant, and we ignore it.
2288   State.Column = Current.LastLineColumnWidth;
2289 
2290   if (ColumnsUsed > getColumnLimit(State))
2291     return Style.PenaltyExcessCharacter * (ColumnsUsed - getColumnLimit(State));
2292   return 0;
2293 }
2294 
2295 unsigned ContinuationIndenter::handleEndOfLine(const FormatToken &Current,
2296                                                LineState &State, bool DryRun,
2297                                                bool AllowBreak, bool Newline) {
2298   unsigned Penalty = 0;
2299   // Compute the raw string style to use in case this is a raw string literal
2300   // that can be reformatted.
2301   auto RawStringStyle = getRawStringStyle(Current, State);
2302   if (RawStringStyle && !Current.Finalized) {
2303     Penalty = reformatRawStringLiteral(Current, State, *RawStringStyle, DryRun,
2304                                        Newline);
2305   } else if (Current.IsMultiline && Current.isNot(TT_BlockComment)) {
2306     // Don't break multi-line tokens other than block comments and raw string
2307     // literals. Instead, just update the state.
2308     Penalty = addMultilineToken(Current, State);
2309   } else if (State.Line->Type != LT_ImportStatement) {
2310     // We generally don't break import statements.
2311     LineState OriginalState = State;
2312 
2313     // Whether we force the reflowing algorithm to stay strictly within the
2314     // column limit.
2315     bool Strict = false;
2316     // Whether the first non-strict attempt at reflowing did intentionally
2317     // exceed the column limit.
2318     bool Exceeded = false;
2319     std::tie(Penalty, Exceeded) = breakProtrudingToken(
2320         Current, State, AllowBreak, /*DryRun=*/true, Strict);
2321     if (Exceeded) {
2322       // If non-strict reflowing exceeds the column limit, try whether strict
2323       // reflowing leads to an overall lower penalty.
2324       LineState StrictState = OriginalState;
2325       unsigned StrictPenalty =
2326           breakProtrudingToken(Current, StrictState, AllowBreak,
2327                                /*DryRun=*/true, /*Strict=*/true)
2328               .first;
2329       Strict = StrictPenalty <= Penalty;
2330       if (Strict) {
2331         Penalty = StrictPenalty;
2332         State = StrictState;
2333       }
2334     }
2335     if (!DryRun) {
2336       // If we're not in dry-run mode, apply the changes with the decision on
2337       // strictness made above.
2338       breakProtrudingToken(Current, OriginalState, AllowBreak, /*DryRun=*/false,
2339                            Strict);
2340     }
2341   }
2342   if (State.Column > getColumnLimit(State)) {
2343     unsigned ExcessCharacters = State.Column - getColumnLimit(State);
2344     Penalty += Style.PenaltyExcessCharacter * ExcessCharacters;
2345   }
2346   return Penalty;
2347 }
2348 
2349 // Returns the enclosing function name of a token, or the empty string if not
2350 // found.
2351 static StringRef getEnclosingFunctionName(const FormatToken &Current) {
2352   // Look for: 'function(' or 'function<templates>(' before Current.
2353   auto Tok = Current.getPreviousNonComment();
2354   if (!Tok || Tok->isNot(tok::l_paren))
2355     return "";
2356   Tok = Tok->getPreviousNonComment();
2357   if (!Tok)
2358     return "";
2359   if (Tok->is(TT_TemplateCloser)) {
2360     Tok = Tok->MatchingParen;
2361     if (Tok)
2362       Tok = Tok->getPreviousNonComment();
2363   }
2364   if (!Tok || Tok->isNot(tok::identifier))
2365     return "";
2366   return Tok->TokenText;
2367 }
2368 
2369 std::optional<FormatStyle>
2370 ContinuationIndenter::getRawStringStyle(const FormatToken &Current,
2371                                         const LineState &State) {
2372   if (!Current.isStringLiteral())
2373     return std::nullopt;
2374   auto Delimiter = getRawStringDelimiter(Current.TokenText);
2375   if (!Delimiter)
2376     return std::nullopt;
2377   auto RawStringStyle = RawStringFormats.getDelimiterStyle(*Delimiter);
2378   if (!RawStringStyle && Delimiter->empty()) {
2379     RawStringStyle = RawStringFormats.getEnclosingFunctionStyle(
2380         getEnclosingFunctionName(Current));
2381   }
2382   if (!RawStringStyle)
2383     return std::nullopt;
2384   RawStringStyle->ColumnLimit = getColumnLimit(State);
2385   return RawStringStyle;
2386 }
2387 
2388 std::unique_ptr<BreakableToken>
2389 ContinuationIndenter::createBreakableToken(const FormatToken &Current,
2390                                            LineState &State, bool AllowBreak) {
2391   unsigned StartColumn = State.Column - Current.ColumnWidth;
2392   if (Current.isStringLiteral()) {
2393     // Strings in JSON cannot be broken. Breaking strings in JavaScript is
2394     // disabled for now.
2395     if (Style.isJson() || Style.isJavaScript() || !Style.BreakStringLiterals ||
2396         !AllowBreak) {
2397       return nullptr;
2398     }
2399 
2400     // Don't break string literals inside preprocessor directives (except for
2401     // #define directives, as their contents are stored in separate lines and
2402     // are not affected by this check).
2403     // This way we avoid breaking code with line directives and unknown
2404     // preprocessor directives that contain long string literals.
2405     if (State.Line->Type == LT_PreprocessorDirective)
2406       return nullptr;
2407     // Exempts unterminated string literals from line breaking. The user will
2408     // likely want to terminate the string before any line breaking is done.
2409     if (Current.IsUnterminatedLiteral)
2410       return nullptr;
2411     // Don't break string literals inside Objective-C array literals (doing so
2412     // raises the warning -Wobjc-string-concatenation).
2413     if (State.Stack.back().IsInsideObjCArrayLiteral)
2414       return nullptr;
2415 
2416     // The "DPI"/"DPI-C" in SystemVerilog direct programming interface
2417     // imports/exports cannot be split, e.g.
2418     // `import "DPI" function foo();`
2419     // FIXME: make this use same infra as C++ import checks
2420     if (Style.isVerilog() && Current.Previous &&
2421         Current.Previous->isOneOf(tok::kw_export, Keywords.kw_import)) {
2422       return nullptr;
2423     }
2424     StringRef Text = Current.TokenText;
2425 
2426     // We need this to address the case where there is an unbreakable tail only
2427     // if certain other formatting decisions have been taken. The
2428     // UnbreakableTailLength of Current is an overapproximation in that case and
2429     // we need to be correct here.
2430     unsigned UnbreakableTailLength = (State.NextToken && canBreak(State))
2431                                          ? 0
2432                                          : Current.UnbreakableTailLength;
2433 
2434     if (Style.isVerilog() || Style.Language == FormatStyle::LK_Java ||
2435         Style.isJavaScript() || Style.isCSharp()) {
2436       BreakableStringLiteralUsingOperators::QuoteStyleType QuoteStyle;
2437       if (Style.isJavaScript() && Text.starts_with("'") &&
2438           Text.ends_with("'")) {
2439         QuoteStyle = BreakableStringLiteralUsingOperators::SingleQuotes;
2440       } else if (Style.isCSharp() && Text.starts_with("@\"") &&
2441                  Text.ends_with("\"")) {
2442         QuoteStyle = BreakableStringLiteralUsingOperators::AtDoubleQuotes;
2443       } else if (Text.starts_with("\"") && Text.ends_with("\"")) {
2444         QuoteStyle = BreakableStringLiteralUsingOperators::DoubleQuotes;
2445       } else {
2446         return nullptr;
2447       }
2448       return std::make_unique<BreakableStringLiteralUsingOperators>(
2449           Current, QuoteStyle,
2450           /*UnindentPlus=*/shouldUnindentNextOperator(Current), StartColumn,
2451           UnbreakableTailLength, State.Line->InPPDirective, Encoding, Style);
2452     }
2453 
2454     StringRef Prefix;
2455     StringRef Postfix;
2456     // FIXME: Handle whitespace between '_T', '(', '"..."', and ')'.
2457     // FIXME: Store Prefix and Suffix (or PrefixLength and SuffixLength to
2458     // reduce the overhead) for each FormatToken, which is a string, so that we
2459     // don't run multiple checks here on the hot path.
2460     if ((Text.ends_with(Postfix = "\"") &&
2461          (Text.starts_with(Prefix = "@\"") || Text.starts_with(Prefix = "\"") ||
2462           Text.starts_with(Prefix = "u\"") ||
2463           Text.starts_with(Prefix = "U\"") ||
2464           Text.starts_with(Prefix = "u8\"") ||
2465           Text.starts_with(Prefix = "L\""))) ||
2466         (Text.starts_with(Prefix = "_T(\"") &&
2467          Text.ends_with(Postfix = "\")"))) {
2468       return std::make_unique<BreakableStringLiteral>(
2469           Current, StartColumn, Prefix, Postfix, UnbreakableTailLength,
2470           State.Line->InPPDirective, Encoding, Style);
2471     }
2472   } else if (Current.is(TT_BlockComment)) {
2473     if (Style.ReflowComments == FormatStyle::RCS_Never ||
2474         // If a comment token switches formatting, like
2475         // /* clang-format on */, we don't want to break it further,
2476         // but we may still want to adjust its indentation.
2477         switchesFormatting(Current)) {
2478       return nullptr;
2479     }
2480     return std::make_unique<BreakableBlockComment>(
2481         Current, StartColumn, Current.OriginalColumn, !Current.Previous,
2482         State.Line->InPPDirective, Encoding, Style, Whitespaces.useCRLF());
2483   } else if (Current.is(TT_LineComment) &&
2484              (!Current.Previous ||
2485               Current.Previous->isNot(TT_ImplicitStringLiteral))) {
2486     bool RegularComments = [&]() {
2487       for (const FormatToken *T = &Current; T && T->is(TT_LineComment);
2488            T = T->Next) {
2489         if (!(T->TokenText.starts_with("//") || T->TokenText.starts_with("#")))
2490           return false;
2491       }
2492       return true;
2493     }();
2494     if (Style.ReflowComments == FormatStyle::RCS_Never ||
2495         CommentPragmasRegex.match(Current.TokenText.substr(2)) ||
2496         switchesFormatting(Current) || !RegularComments) {
2497       return nullptr;
2498     }
2499     return std::make_unique<BreakableLineCommentSection>(
2500         Current, StartColumn, /*InPPDirective=*/false, Encoding, Style);
2501   }
2502   return nullptr;
2503 }
2504 
2505 std::pair<unsigned, bool>
2506 ContinuationIndenter::breakProtrudingToken(const FormatToken &Current,
2507                                            LineState &State, bool AllowBreak,
2508                                            bool DryRun, bool Strict) {
2509   std::unique_ptr<const BreakableToken> Token =
2510       createBreakableToken(Current, State, AllowBreak);
2511   if (!Token)
2512     return {0, false};
2513   assert(Token->getLineCount() > 0);
2514   unsigned ColumnLimit = getColumnLimit(State);
2515   if (Current.is(TT_LineComment)) {
2516     // We don't insert backslashes when breaking line comments.
2517     ColumnLimit = Style.ColumnLimit;
2518   }
2519   if (ColumnLimit == 0) {
2520     // To make the rest of the function easier set the column limit to the
2521     // maximum, if there should be no limit.
2522     ColumnLimit = std::numeric_limits<decltype(ColumnLimit)>::max();
2523   }
2524   if (Current.UnbreakableTailLength >= ColumnLimit)
2525     return {0, false};
2526   // ColumnWidth was already accounted into State.Column before calling
2527   // breakProtrudingToken.
2528   unsigned StartColumn = State.Column - Current.ColumnWidth;
2529   unsigned NewBreakPenalty = Current.isStringLiteral()
2530                                  ? Style.PenaltyBreakString
2531                                  : Style.PenaltyBreakComment;
2532   // Stores whether we intentionally decide to let a line exceed the column
2533   // limit.
2534   bool Exceeded = false;
2535   // Stores whether we introduce a break anywhere in the token.
2536   bool BreakInserted = Token->introducesBreakBeforeToken();
2537   // Store whether we inserted a new line break at the end of the previous
2538   // logical line.
2539   bool NewBreakBefore = false;
2540   // We use a conservative reflowing strategy. Reflow starts after a line is
2541   // broken or the corresponding whitespace compressed. Reflow ends as soon as a
2542   // line that doesn't get reflown with the previous line is reached.
2543   bool Reflow = false;
2544   // Keep track of where we are in the token:
2545   // Where we are in the content of the current logical line.
2546   unsigned TailOffset = 0;
2547   // The column number we're currently at.
2548   unsigned ContentStartColumn =
2549       Token->getContentStartColumn(0, /*Break=*/false);
2550   // The number of columns left in the current logical line after TailOffset.
2551   unsigned RemainingTokenColumns =
2552       Token->getRemainingLength(0, TailOffset, ContentStartColumn);
2553   // Adapt the start of the token, for example indent.
2554   if (!DryRun)
2555     Token->adaptStartOfLine(0, Whitespaces);
2556 
2557   unsigned ContentIndent = 0;
2558   unsigned Penalty = 0;
2559   LLVM_DEBUG(llvm::dbgs() << "Breaking protruding token at column "
2560                           << StartColumn << ".\n");
2561   for (unsigned LineIndex = 0, EndIndex = Token->getLineCount();
2562        LineIndex != EndIndex; ++LineIndex) {
2563     LLVM_DEBUG(llvm::dbgs()
2564                << "  Line: " << LineIndex << " (Reflow: " << Reflow << ")\n");
2565     NewBreakBefore = false;
2566     // If we did reflow the previous line, we'll try reflowing again. Otherwise
2567     // we'll start reflowing if the current line is broken or whitespace is
2568     // compressed.
2569     bool TryReflow = Reflow;
2570     // Break the current token until we can fit the rest of the line.
2571     while (ContentStartColumn + RemainingTokenColumns > ColumnLimit) {
2572       LLVM_DEBUG(llvm::dbgs() << "    Over limit, need: "
2573                               << (ContentStartColumn + RemainingTokenColumns)
2574                               << ", space: " << ColumnLimit
2575                               << ", reflown prefix: " << ContentStartColumn
2576                               << ", offset in line: " << TailOffset << "\n");
2577       // If the current token doesn't fit, find the latest possible split in the
2578       // current line so that breaking at it will be under the column limit.
2579       // FIXME: Use the earliest possible split while reflowing to correctly
2580       // compress whitespace within a line.
2581       BreakableToken::Split Split =
2582           Token->getSplit(LineIndex, TailOffset, ColumnLimit,
2583                           ContentStartColumn, CommentPragmasRegex);
2584       if (Split.first == StringRef::npos) {
2585         // No break opportunity - update the penalty and continue with the next
2586         // logical line.
2587         if (LineIndex < EndIndex - 1) {
2588           // The last line's penalty is handled in addNextStateToQueue() or when
2589           // calling replaceWhitespaceAfterLastLine below.
2590           Penalty += Style.PenaltyExcessCharacter *
2591                      (ContentStartColumn + RemainingTokenColumns - ColumnLimit);
2592         }
2593         LLVM_DEBUG(llvm::dbgs() << "    No break opportunity.\n");
2594         break;
2595       }
2596       assert(Split.first != 0);
2597 
2598       if (Token->supportsReflow()) {
2599         // Check whether the next natural split point after the current one can
2600         // still fit the line, either because we can compress away whitespace,
2601         // or because the penalty the excess characters introduce is lower than
2602         // the break penalty.
2603         // We only do this for tokens that support reflowing, and thus allow us
2604         // to change the whitespace arbitrarily (e.g. comments).
2605         // Other tokens, like string literals, can be broken on arbitrary
2606         // positions.
2607 
2608         // First, compute the columns from TailOffset to the next possible split
2609         // position.
2610         // For example:
2611         // ColumnLimit:     |
2612         // // Some text   that    breaks
2613         //    ^ tail offset
2614         //             ^-- split
2615         //    ^-------- to split columns
2616         //                    ^--- next split
2617         //    ^--------------- to next split columns
2618         unsigned ToSplitColumns = Token->getRangeLength(
2619             LineIndex, TailOffset, Split.first, ContentStartColumn);
2620         LLVM_DEBUG(llvm::dbgs() << "    ToSplit: " << ToSplitColumns << "\n");
2621 
2622         BreakableToken::Split NextSplit = Token->getSplit(
2623             LineIndex, TailOffset + Split.first + Split.second, ColumnLimit,
2624             ContentStartColumn + ToSplitColumns + 1, CommentPragmasRegex);
2625         // Compute the columns necessary to fit the next non-breakable sequence
2626         // into the current line.
2627         unsigned ToNextSplitColumns = 0;
2628         if (NextSplit.first == StringRef::npos) {
2629           ToNextSplitColumns = Token->getRemainingLength(LineIndex, TailOffset,
2630                                                          ContentStartColumn);
2631         } else {
2632           ToNextSplitColumns = Token->getRangeLength(
2633               LineIndex, TailOffset,
2634               Split.first + Split.second + NextSplit.first, ContentStartColumn);
2635         }
2636         // Compress the whitespace between the break and the start of the next
2637         // unbreakable sequence.
2638         ToNextSplitColumns =
2639             Token->getLengthAfterCompression(ToNextSplitColumns, Split);
2640         LLVM_DEBUG(llvm::dbgs()
2641                    << "    ContentStartColumn: " << ContentStartColumn << "\n");
2642         LLVM_DEBUG(llvm::dbgs()
2643                    << "    ToNextSplit: " << ToNextSplitColumns << "\n");
2644         // If the whitespace compression makes us fit, continue on the current
2645         // line.
2646         bool ContinueOnLine =
2647             ContentStartColumn + ToNextSplitColumns <= ColumnLimit;
2648         unsigned ExcessCharactersPenalty = 0;
2649         if (!ContinueOnLine && !Strict) {
2650           // Similarly, if the excess characters' penalty is lower than the
2651           // penalty of introducing a new break, continue on the current line.
2652           ExcessCharactersPenalty =
2653               (ContentStartColumn + ToNextSplitColumns - ColumnLimit) *
2654               Style.PenaltyExcessCharacter;
2655           LLVM_DEBUG(llvm::dbgs()
2656                      << "    Penalty excess: " << ExcessCharactersPenalty
2657                      << "\n            break : " << NewBreakPenalty << "\n");
2658           if (ExcessCharactersPenalty < NewBreakPenalty) {
2659             Exceeded = true;
2660             ContinueOnLine = true;
2661           }
2662         }
2663         if (ContinueOnLine) {
2664           LLVM_DEBUG(llvm::dbgs() << "    Continuing on line...\n");
2665           // The current line fits after compressing the whitespace - reflow
2666           // the next line into it if possible.
2667           TryReflow = true;
2668           if (!DryRun) {
2669             Token->compressWhitespace(LineIndex, TailOffset, Split,
2670                                       Whitespaces);
2671           }
2672           // When we continue on the same line, leave one space between content.
2673           ContentStartColumn += ToSplitColumns + 1;
2674           Penalty += ExcessCharactersPenalty;
2675           TailOffset += Split.first + Split.second;
2676           RemainingTokenColumns = Token->getRemainingLength(
2677               LineIndex, TailOffset, ContentStartColumn);
2678           continue;
2679         }
2680       }
2681       LLVM_DEBUG(llvm::dbgs() << "    Breaking...\n");
2682       // Update the ContentIndent only if the current line was not reflown with
2683       // the previous line, since in that case the previous line should still
2684       // determine the ContentIndent. Also never intent the last line.
2685       if (!Reflow)
2686         ContentIndent = Token->getContentIndent(LineIndex);
2687       LLVM_DEBUG(llvm::dbgs()
2688                  << "    ContentIndent: " << ContentIndent << "\n");
2689       ContentStartColumn = ContentIndent + Token->getContentStartColumn(
2690                                                LineIndex, /*Break=*/true);
2691 
2692       unsigned NewRemainingTokenColumns = Token->getRemainingLength(
2693           LineIndex, TailOffset + Split.first + Split.second,
2694           ContentStartColumn);
2695       if (NewRemainingTokenColumns == 0) {
2696         // No content to indent.
2697         ContentIndent = 0;
2698         ContentStartColumn =
2699             Token->getContentStartColumn(LineIndex, /*Break=*/true);
2700         NewRemainingTokenColumns = Token->getRemainingLength(
2701             LineIndex, TailOffset + Split.first + Split.second,
2702             ContentStartColumn);
2703       }
2704 
2705       // When breaking before a tab character, it may be moved by a few columns,
2706       // but will still be expanded to the next tab stop, so we don't save any
2707       // columns.
2708       if (NewRemainingTokenColumns >= RemainingTokenColumns) {
2709         // FIXME: Do we need to adjust the penalty?
2710         break;
2711       }
2712 
2713       LLVM_DEBUG(llvm::dbgs() << "    Breaking at: " << TailOffset + Split.first
2714                               << ", " << Split.second << "\n");
2715       if (!DryRun) {
2716         Token->insertBreak(LineIndex, TailOffset, Split, ContentIndent,
2717                            Whitespaces);
2718       }
2719 
2720       Penalty += NewBreakPenalty;
2721       TailOffset += Split.first + Split.second;
2722       RemainingTokenColumns = NewRemainingTokenColumns;
2723       BreakInserted = true;
2724       NewBreakBefore = true;
2725     }
2726     // In case there's another line, prepare the state for the start of the next
2727     // line.
2728     if (LineIndex + 1 != EndIndex) {
2729       unsigned NextLineIndex = LineIndex + 1;
2730       if (NewBreakBefore) {
2731         // After breaking a line, try to reflow the next line into the current
2732         // one once RemainingTokenColumns fits.
2733         TryReflow = true;
2734       }
2735       if (TryReflow) {
2736         // We decided that we want to try reflowing the next line into the
2737         // current one.
2738         // We will now adjust the state as if the reflow is successful (in
2739         // preparation for the next line), and see whether that works. If we
2740         // decide that we cannot reflow, we will later reset the state to the
2741         // start of the next line.
2742         Reflow = false;
2743         // As we did not continue breaking the line, RemainingTokenColumns is
2744         // known to fit after ContentStartColumn. Adapt ContentStartColumn to
2745         // the position at which we want to format the next line if we do
2746         // actually reflow.
2747         // When we reflow, we need to add a space between the end of the current
2748         // line and the next line's start column.
2749         ContentStartColumn += RemainingTokenColumns + 1;
2750         // Get the split that we need to reflow next logical line into the end
2751         // of the current one; the split will include any leading whitespace of
2752         // the next logical line.
2753         BreakableToken::Split SplitBeforeNext =
2754             Token->getReflowSplit(NextLineIndex, CommentPragmasRegex);
2755         LLVM_DEBUG(llvm::dbgs()
2756                    << "    Size of reflown text: " << ContentStartColumn
2757                    << "\n    Potential reflow split: ");
2758         if (SplitBeforeNext.first != StringRef::npos) {
2759           LLVM_DEBUG(llvm::dbgs() << SplitBeforeNext.first << ", "
2760                                   << SplitBeforeNext.second << "\n");
2761           TailOffset = SplitBeforeNext.first + SplitBeforeNext.second;
2762           // If the rest of the next line fits into the current line below the
2763           // column limit, we can safely reflow.
2764           RemainingTokenColumns = Token->getRemainingLength(
2765               NextLineIndex, TailOffset, ContentStartColumn);
2766           Reflow = true;
2767           if (ContentStartColumn + RemainingTokenColumns > ColumnLimit) {
2768             LLVM_DEBUG(llvm::dbgs()
2769                        << "    Over limit after reflow, need: "
2770                        << (ContentStartColumn + RemainingTokenColumns)
2771                        << ", space: " << ColumnLimit
2772                        << ", reflown prefix: " << ContentStartColumn
2773                        << ", offset in line: " << TailOffset << "\n");
2774             // If the whole next line does not fit, try to find a point in
2775             // the next line at which we can break so that attaching the part
2776             // of the next line to that break point onto the current line is
2777             // below the column limit.
2778             BreakableToken::Split Split =
2779                 Token->getSplit(NextLineIndex, TailOffset, ColumnLimit,
2780                                 ContentStartColumn, CommentPragmasRegex);
2781             if (Split.first == StringRef::npos) {
2782               LLVM_DEBUG(llvm::dbgs() << "    Did not find later break\n");
2783               Reflow = false;
2784             } else {
2785               // Check whether the first split point gets us below the column
2786               // limit. Note that we will execute this split below as part of
2787               // the normal token breaking and reflow logic within the line.
2788               unsigned ToSplitColumns = Token->getRangeLength(
2789                   NextLineIndex, TailOffset, Split.first, ContentStartColumn);
2790               if (ContentStartColumn + ToSplitColumns > ColumnLimit) {
2791                 LLVM_DEBUG(llvm::dbgs() << "    Next split protrudes, need: "
2792                                         << (ContentStartColumn + ToSplitColumns)
2793                                         << ", space: " << ColumnLimit);
2794                 unsigned ExcessCharactersPenalty =
2795                     (ContentStartColumn + ToSplitColumns - ColumnLimit) *
2796                     Style.PenaltyExcessCharacter;
2797                 if (NewBreakPenalty < ExcessCharactersPenalty)
2798                   Reflow = false;
2799               }
2800             }
2801           }
2802         } else {
2803           LLVM_DEBUG(llvm::dbgs() << "not found.\n");
2804         }
2805       }
2806       if (!Reflow) {
2807         // If we didn't reflow into the next line, the only space to consider is
2808         // the next logical line. Reset our state to match the start of the next
2809         // line.
2810         TailOffset = 0;
2811         ContentStartColumn =
2812             Token->getContentStartColumn(NextLineIndex, /*Break=*/false);
2813         RemainingTokenColumns = Token->getRemainingLength(
2814             NextLineIndex, TailOffset, ContentStartColumn);
2815         // Adapt the start of the token, for example indent.
2816         if (!DryRun)
2817           Token->adaptStartOfLine(NextLineIndex, Whitespaces);
2818       } else {
2819         // If we found a reflow split and have added a new break before the next
2820         // line, we are going to remove the line break at the start of the next
2821         // logical line. For example, here we'll add a new line break after
2822         // 'text', and subsequently delete the line break between 'that' and
2823         // 'reflows'.
2824         //   // some text that
2825         //   // reflows
2826         // ->
2827         //   // some text
2828         //   // that reflows
2829         // When adding the line break, we also added the penalty for it, so we
2830         // need to subtract that penalty again when we remove the line break due
2831         // to reflowing.
2832         if (NewBreakBefore) {
2833           assert(Penalty >= NewBreakPenalty);
2834           Penalty -= NewBreakPenalty;
2835         }
2836         if (!DryRun)
2837           Token->reflow(NextLineIndex, Whitespaces);
2838       }
2839     }
2840   }
2841 
2842   BreakableToken::Split SplitAfterLastLine =
2843       Token->getSplitAfterLastLine(TailOffset);
2844   if (SplitAfterLastLine.first != StringRef::npos) {
2845     LLVM_DEBUG(llvm::dbgs() << "Replacing whitespace after last line.\n");
2846 
2847     // We add the last line's penalty here, since that line is going to be split
2848     // now.
2849     Penalty += Style.PenaltyExcessCharacter *
2850                (ContentStartColumn + RemainingTokenColumns - ColumnLimit);
2851 
2852     if (!DryRun) {
2853       Token->replaceWhitespaceAfterLastLine(TailOffset, SplitAfterLastLine,
2854                                             Whitespaces);
2855     }
2856     ContentStartColumn =
2857         Token->getContentStartColumn(Token->getLineCount() - 1, /*Break=*/true);
2858     RemainingTokenColumns = Token->getRemainingLength(
2859         Token->getLineCount() - 1,
2860         TailOffset + SplitAfterLastLine.first + SplitAfterLastLine.second,
2861         ContentStartColumn);
2862   }
2863 
2864   State.Column = ContentStartColumn + RemainingTokenColumns -
2865                  Current.UnbreakableTailLength;
2866 
2867   if (BreakInserted) {
2868     if (!DryRun)
2869       Token->updateAfterBroken(Whitespaces);
2870 
2871     // If we break the token inside a parameter list, we need to break before
2872     // the next parameter on all levels, so that the next parameter is clearly
2873     // visible. Line comments already introduce a break.
2874     if (Current.isNot(TT_LineComment))
2875       for (ParenState &Paren : State.Stack)
2876         Paren.BreakBeforeParameter = true;
2877 
2878     if (Current.is(TT_BlockComment))
2879       State.NoContinuation = true;
2880 
2881     State.Stack.back().LastSpace = StartColumn;
2882   }
2883 
2884   Token->updateNextToken(State);
2885 
2886   return {Penalty, Exceeded};
2887 }
2888 
2889 unsigned ContinuationIndenter::getColumnLimit(const LineState &State) const {
2890   // In preprocessor directives reserve two chars for trailing " \".
2891   return Style.ColumnLimit - (State.Line->InPPDirective ? 2 : 0);
2892 }
2893 
2894 bool ContinuationIndenter::nextIsMultilineString(const LineState &State) {
2895   const FormatToken &Current = *State.NextToken;
2896   if (!Current.isStringLiteral() || Current.is(TT_ImplicitStringLiteral))
2897     return false;
2898   // We never consider raw string literals "multiline" for the purpose of
2899   // AlwaysBreakBeforeMultilineStrings implementation as they are special-cased
2900   // (see TokenAnnotator::mustBreakBefore().
2901   if (Current.TokenText.starts_with("R\""))
2902     return false;
2903   if (Current.IsMultiline)
2904     return true;
2905   if (Current.getNextNonComment() &&
2906       Current.getNextNonComment()->isStringLiteral()) {
2907     return true; // Implicit concatenation.
2908   }
2909   if (Style.ColumnLimit != 0 && Style.BreakStringLiterals &&
2910       State.Column + Current.ColumnWidth + Current.UnbreakableTailLength >
2911           Style.ColumnLimit) {
2912     return true; // String will be split.
2913   }
2914   return false;
2915 }
2916 
2917 } // namespace format
2918 } // namespace clang
2919