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.
shouldIndentWrappedSelectorName(const FormatStyle & Style,LineType LineType)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.
shouldUnindentNextOperator(const FormatToken & Tok)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.
getLengthToMatchingParen(const FormatToken & Tok,ArrayRef<ParenState> Stack)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
getLengthToNextOperator(const FormatToken & Tok)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.
startsSegmentOfBuilderTypeCall(const FormatToken & Tok)127 static bool startsSegmentOfBuilderTypeCall(const FormatToken &Tok) {
128 return Tok.isMemberAccess() && Tok.Previous && Tok.Previous->closesScope();
129 }
130
131 // Returns \c true if \c Current starts a new parameter.
startsNextParameter(const FormatToken & Current,const FormatStyle & Style)132 static bool startsNextParameter(const FormatToken &Current,
133 const FormatStyle &Style) {
134 const FormatToken &Previous = *Current.Previous;
135 if (Current.is(TT_CtorInitializerComma) &&
136 Style.BreakConstructorInitializers == FormatStyle::BCIS_BeforeComma) {
137 return true;
138 }
139 if (Style.Language == FormatStyle::LK_Proto && Current.is(TT_SelectorName))
140 return true;
141 return Previous.is(tok::comma) && !Current.isTrailingComment() &&
142 ((Previous.isNot(TT_CtorInitializerComma) ||
143 Style.BreakConstructorInitializers !=
144 FormatStyle::BCIS_BeforeComma) &&
145 (Previous.isNot(TT_InheritanceComma) ||
146 Style.BreakInheritanceList != FormatStyle::BILS_BeforeComma));
147 }
148
opensProtoMessageField(const FormatToken & LessTok,const FormatStyle & Style)149 static bool opensProtoMessageField(const FormatToken &LessTok,
150 const FormatStyle &Style) {
151 if (LessTok.isNot(tok::less))
152 return false;
153 return Style.Language == FormatStyle::LK_TextProto ||
154 (Style.Language == FormatStyle::LK_Proto &&
155 (LessTok.NestingLevel > 0 ||
156 (LessTok.Previous && LessTok.Previous->is(tok::equal))));
157 }
158
159 // Returns the delimiter of a raw string literal, or std::nullopt if TokenText
160 // is not the text of a raw string literal. The delimiter could be the empty
161 // string. For example, the delimiter of R"deli(cont)deli" is deli.
getRawStringDelimiter(StringRef TokenText)162 static std::optional<StringRef> getRawStringDelimiter(StringRef TokenText) {
163 if (TokenText.size() < 5 // The smallest raw string possible is 'R"()"'.
164 || !TokenText.starts_with("R\"") || !TokenText.ends_with("\"")) {
165 return std::nullopt;
166 }
167
168 // A raw string starts with 'R"<delimiter>(' and delimiter is ascii and has
169 // size at most 16 by the standard, so the first '(' must be among the first
170 // 19 bytes.
171 size_t LParenPos = TokenText.substr(0, 19).find_first_of('(');
172 if (LParenPos == StringRef::npos)
173 return std::nullopt;
174 StringRef Delimiter = TokenText.substr(2, LParenPos - 2);
175
176 // Check that the string ends in ')Delimiter"'.
177 size_t RParenPos = TokenText.size() - Delimiter.size() - 2;
178 if (TokenText[RParenPos] != ')')
179 return std::nullopt;
180 if (!TokenText.substr(RParenPos + 1).starts_with(Delimiter))
181 return std::nullopt;
182 return Delimiter;
183 }
184
185 // Returns the canonical delimiter for \p Language, or the empty string if no
186 // canonical delimiter is specified.
187 static StringRef
getCanonicalRawStringDelimiter(const FormatStyle & Style,FormatStyle::LanguageKind Language)188 getCanonicalRawStringDelimiter(const FormatStyle &Style,
189 FormatStyle::LanguageKind Language) {
190 for (const auto &Format : Style.RawStringFormats)
191 if (Format.Language == Language)
192 return StringRef(Format.CanonicalDelimiter);
193 return "";
194 }
195
RawStringFormatStyleManager(const FormatStyle & CodeStyle)196 RawStringFormatStyleManager::RawStringFormatStyleManager(
197 const FormatStyle &CodeStyle) {
198 for (const auto &RawStringFormat : CodeStyle.RawStringFormats) {
199 std::optional<FormatStyle> LanguageStyle =
200 CodeStyle.GetLanguageStyle(RawStringFormat.Language);
201 if (!LanguageStyle) {
202 FormatStyle PredefinedStyle;
203 if (!getPredefinedStyle(RawStringFormat.BasedOnStyle,
204 RawStringFormat.Language, &PredefinedStyle)) {
205 PredefinedStyle = getLLVMStyle();
206 PredefinedStyle.Language = RawStringFormat.Language;
207 }
208 LanguageStyle = PredefinedStyle;
209 }
210 LanguageStyle->ColumnLimit = CodeStyle.ColumnLimit;
211 for (StringRef Delimiter : RawStringFormat.Delimiters)
212 DelimiterStyle.insert({Delimiter, *LanguageStyle});
213 for (StringRef EnclosingFunction : RawStringFormat.EnclosingFunctions)
214 EnclosingFunctionStyle.insert({EnclosingFunction, *LanguageStyle});
215 }
216 }
217
218 std::optional<FormatStyle>
getDelimiterStyle(StringRef Delimiter) const219 RawStringFormatStyleManager::getDelimiterStyle(StringRef Delimiter) const {
220 auto It = DelimiterStyle.find(Delimiter);
221 if (It == DelimiterStyle.end())
222 return std::nullopt;
223 return It->second;
224 }
225
226 std::optional<FormatStyle>
getEnclosingFunctionStyle(StringRef EnclosingFunction) const227 RawStringFormatStyleManager::getEnclosingFunctionStyle(
228 StringRef EnclosingFunction) const {
229 auto It = EnclosingFunctionStyle.find(EnclosingFunction);
230 if (It == EnclosingFunctionStyle.end())
231 return std::nullopt;
232 return It->second;
233 }
234
ContinuationIndenter(const FormatStyle & Style,const AdditionalKeywords & Keywords,const SourceManager & SourceMgr,WhitespaceManager & Whitespaces,encoding::Encoding Encoding,bool BinPackInconclusiveFunctions)235 ContinuationIndenter::ContinuationIndenter(const FormatStyle &Style,
236 const AdditionalKeywords &Keywords,
237 const SourceManager &SourceMgr,
238 WhitespaceManager &Whitespaces,
239 encoding::Encoding Encoding,
240 bool BinPackInconclusiveFunctions)
241 : Style(Style), Keywords(Keywords), SourceMgr(SourceMgr),
242 Whitespaces(Whitespaces), Encoding(Encoding),
243 BinPackInconclusiveFunctions(BinPackInconclusiveFunctions),
244 CommentPragmasRegex(Style.CommentPragmas), RawStringFormats(Style) {}
245
getInitialState(unsigned FirstIndent,unsigned FirstStartColumn,const AnnotatedLine * Line,bool DryRun)246 LineState ContinuationIndenter::getInitialState(unsigned FirstIndent,
247 unsigned FirstStartColumn,
248 const AnnotatedLine *Line,
249 bool DryRun) {
250 LineState State;
251 State.FirstIndent = FirstIndent;
252 if (FirstStartColumn && Line->First->NewlinesBefore == 0)
253 State.Column = FirstStartColumn;
254 else
255 State.Column = FirstIndent;
256 // With preprocessor directive indentation, the line starts on column 0
257 // since it's indented after the hash, but FirstIndent is set to the
258 // preprocessor indent.
259 if (Style.IndentPPDirectives == FormatStyle::PPDIS_AfterHash &&
260 (Line->Type == LT_PreprocessorDirective ||
261 Line->Type == LT_ImportStatement)) {
262 State.Column = 0;
263 }
264 State.Line = Line;
265 State.NextToken = Line->First;
266 State.Stack.push_back(ParenState(/*Tok=*/nullptr, FirstIndent, FirstIndent,
267 /*AvoidBinPacking=*/false,
268 /*NoLineBreak=*/false));
269 State.NoContinuation = false;
270 State.StartOfStringLiteral = 0;
271 State.NoLineBreak = false;
272 State.StartOfLineLevel = 0;
273 State.LowestLevelOnLine = 0;
274 State.IgnoreStackForComparison = false;
275
276 if (Style.Language == FormatStyle::LK_TextProto) {
277 // We need this in order to deal with the bin packing of text fields at
278 // global scope.
279 auto &CurrentState = State.Stack.back();
280 CurrentState.AvoidBinPacking = true;
281 CurrentState.BreakBeforeParameter = true;
282 CurrentState.AlignColons = false;
283 }
284
285 // The first token has already been indented and thus consumed.
286 moveStateToNextToken(State, DryRun, /*Newline=*/false);
287 return State;
288 }
289
canBreak(const LineState & State)290 bool ContinuationIndenter::canBreak(const LineState &State) {
291 const FormatToken &Current = *State.NextToken;
292 const FormatToken &Previous = *Current.Previous;
293 const auto &CurrentState = State.Stack.back();
294 assert(&Previous == Current.Previous);
295 if (!Current.CanBreakBefore && !(CurrentState.BreakBeforeClosingBrace &&
296 Current.closesBlockOrBlockTypeList(Style))) {
297 return false;
298 }
299 // The opening "{" of a braced list has to be on the same line as the first
300 // element if it is nested in another braced init list or function call.
301 if (!Current.MustBreakBefore && Previous.is(tok::l_brace) &&
302 Previous.isNot(TT_DictLiteral) && Previous.is(BK_BracedInit) &&
303 Previous.Previous &&
304 Previous.Previous->isOneOf(tok::l_brace, tok::l_paren, tok::comma)) {
305 return false;
306 }
307 // This prevents breaks like:
308 // ...
309 // SomeParameter, OtherParameter).DoSomething(
310 // ...
311 // As they hide "DoSomething" and are generally bad for readability.
312 if (Previous.opensScope() && Previous.isNot(tok::l_brace) &&
313 State.LowestLevelOnLine < State.StartOfLineLevel &&
314 State.LowestLevelOnLine < Current.NestingLevel) {
315 return false;
316 }
317 if (Current.isMemberAccess() && CurrentState.ContainsUnwrappedBuilder)
318 return false;
319
320 // Don't create a 'hanging' indent if there are multiple blocks in a single
321 // statement and we are aligning lambda blocks to their signatures.
322 if (Previous.is(tok::l_brace) && State.Stack.size() > 1 &&
323 State.Stack[State.Stack.size() - 2].NestedBlockInlined &&
324 State.Stack[State.Stack.size() - 2].HasMultipleNestedBlocks &&
325 Style.LambdaBodyIndentation == FormatStyle::LBI_Signature) {
326 return false;
327 }
328
329 // Don't break after very short return types (e.g. "void") as that is often
330 // unexpected.
331 if (Current.is(TT_FunctionDeclarationName) && State.Column < 6) {
332 if (Style.AlwaysBreakAfterReturnType == FormatStyle::RTBS_None)
333 return false;
334 }
335
336 // If binary operators are moved to the next line (including commas for some
337 // styles of constructor initializers), that's always ok.
338 if (!Current.isOneOf(TT_BinaryOperator, tok::comma) &&
339 // Allow breaking opening brace of lambdas (when passed as function
340 // arguments) to a new line when BeforeLambdaBody brace wrapping is
341 // enabled.
342 (!Style.BraceWrapping.BeforeLambdaBody ||
343 Current.isNot(TT_LambdaLBrace)) &&
344 CurrentState.NoLineBreakInOperand) {
345 return false;
346 }
347
348 if (Previous.is(tok::l_square) && Previous.is(TT_ObjCMethodExpr))
349 return false;
350
351 if (Current.is(TT_ConditionalExpr) && Previous.is(tok::r_paren) &&
352 Previous.MatchingParen && Previous.MatchingParen->Previous &&
353 Previous.MatchingParen->Previous->MatchingParen &&
354 Previous.MatchingParen->Previous->MatchingParen->is(TT_LambdaLBrace)) {
355 // We have a lambda within a conditional expression, allow breaking here.
356 assert(Previous.MatchingParen->Previous->is(tok::r_brace));
357 return true;
358 }
359
360 return !State.NoLineBreak && !CurrentState.NoLineBreak;
361 }
362
mustBreak(const LineState & State)363 bool ContinuationIndenter::mustBreak(const LineState &State) {
364 const FormatToken &Current = *State.NextToken;
365 const FormatToken &Previous = *Current.Previous;
366 const auto &CurrentState = State.Stack.back();
367 if (Style.BraceWrapping.BeforeLambdaBody && Current.CanBreakBefore &&
368 Current.is(TT_LambdaLBrace) && Previous.isNot(TT_LineComment)) {
369 auto LambdaBodyLength = getLengthToMatchingParen(Current, State.Stack);
370 return LambdaBodyLength > getColumnLimit(State);
371 }
372 if (Current.MustBreakBefore ||
373 (Current.is(TT_InlineASMColon) &&
374 (Style.BreakBeforeInlineASMColon == FormatStyle::BBIAS_Always ||
375 (Style.BreakBeforeInlineASMColon == FormatStyle::BBIAS_OnlyMultiline &&
376 Style.ColumnLimit > 0)))) {
377 return true;
378 }
379 if (CurrentState.BreakBeforeClosingBrace &&
380 (Current.closesBlockOrBlockTypeList(Style) ||
381 (Current.is(tok::r_brace) &&
382 Current.isBlockIndentedInitRBrace(Style)))) {
383 return true;
384 }
385 if (CurrentState.BreakBeforeClosingParen && Current.is(tok::r_paren))
386 return true;
387 if (Style.Language == FormatStyle::LK_ObjC &&
388 Style.ObjCBreakBeforeNestedBlockParam &&
389 Current.ObjCSelectorNameParts > 1 &&
390 Current.startsSequence(TT_SelectorName, tok::colon, tok::caret)) {
391 return true;
392 }
393 // Avoid producing inconsistent states by requiring breaks where they are not
394 // permitted for C# generic type constraints.
395 if (CurrentState.IsCSharpGenericTypeConstraint &&
396 Previous.isNot(TT_CSharpGenericTypeConstraintComma)) {
397 return false;
398 }
399 if ((startsNextParameter(Current, Style) || Previous.is(tok::semi) ||
400 (Previous.is(TT_TemplateCloser) && Current.is(TT_StartOfName) &&
401 State.Line->First->isNot(TT_AttributeSquare) && Style.isCpp() &&
402 // FIXME: This is a temporary workaround for the case where clang-format
403 // sets BreakBeforeParameter to avoid bin packing and this creates a
404 // completely unnecessary line break after a template type that isn't
405 // line-wrapped.
406 (Previous.NestingLevel == 1 || Style.BinPackParameters)) ||
407 (Style.BreakBeforeTernaryOperators && Current.is(TT_ConditionalExpr) &&
408 Previous.isNot(tok::question)) ||
409 (!Style.BreakBeforeTernaryOperators &&
410 Previous.is(TT_ConditionalExpr))) &&
411 CurrentState.BreakBeforeParameter && !Current.isTrailingComment() &&
412 !Current.isOneOf(tok::r_paren, tok::r_brace)) {
413 return true;
414 }
415 if (CurrentState.IsChainedConditional &&
416 ((Style.BreakBeforeTernaryOperators && Current.is(TT_ConditionalExpr) &&
417 Current.is(tok::colon)) ||
418 (!Style.BreakBeforeTernaryOperators && Previous.is(TT_ConditionalExpr) &&
419 Previous.is(tok::colon)))) {
420 return true;
421 }
422 if (((Previous.is(TT_DictLiteral) && Previous.is(tok::l_brace)) ||
423 (Previous.is(TT_ArrayInitializerLSquare) &&
424 Previous.ParameterCount > 1) ||
425 opensProtoMessageField(Previous, Style)) &&
426 Style.ColumnLimit > 0 &&
427 getLengthToMatchingParen(Previous, State.Stack) + State.Column - 1 >
428 getColumnLimit(State)) {
429 return true;
430 }
431
432 const FormatToken &BreakConstructorInitializersToken =
433 Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon
434 ? Previous
435 : Current;
436 if (BreakConstructorInitializersToken.is(TT_CtorInitializerColon) &&
437 (State.Column + State.Line->Last->TotalLength - Previous.TotalLength >
438 getColumnLimit(State) ||
439 CurrentState.BreakBeforeParameter) &&
440 (!Current.isTrailingComment() || Current.NewlinesBefore > 0) &&
441 (Style.AllowShortFunctionsOnASingleLine != FormatStyle::SFS_All ||
442 Style.BreakConstructorInitializers != FormatStyle::BCIS_BeforeColon ||
443 Style.ColumnLimit != 0)) {
444 return true;
445 }
446
447 if (Current.is(TT_ObjCMethodExpr) && Previous.isNot(TT_SelectorName) &&
448 State.Line->startsWith(TT_ObjCMethodSpecifier)) {
449 return true;
450 }
451 if (Current.is(TT_SelectorName) && Previous.isNot(tok::at) &&
452 CurrentState.ObjCSelectorNameFound && CurrentState.BreakBeforeParameter &&
453 (Style.ObjCBreakBeforeNestedBlockParam ||
454 !Current.startsSequence(TT_SelectorName, tok::colon, tok::caret))) {
455 return true;
456 }
457
458 unsigned NewLineColumn = getNewLineColumn(State);
459 if (Current.isMemberAccess() && Style.ColumnLimit != 0 &&
460 State.Column + getLengthToNextOperator(Current) > Style.ColumnLimit &&
461 (State.Column > NewLineColumn ||
462 Current.NestingLevel < State.StartOfLineLevel)) {
463 return true;
464 }
465
466 if (startsSegmentOfBuilderTypeCall(Current) &&
467 (CurrentState.CallContinuation != 0 ||
468 CurrentState.BreakBeforeParameter) &&
469 // JavaScript is treated different here as there is a frequent pattern:
470 // SomeFunction(function() {
471 // ...
472 // }.bind(...));
473 // FIXME: We should find a more generic solution to this problem.
474 !(State.Column <= NewLineColumn && Style.isJavaScript()) &&
475 !(Previous.closesScopeAfterBlock() && State.Column <= NewLineColumn)) {
476 return true;
477 }
478
479 // If the template declaration spans multiple lines, force wrap before the
480 // function/class declaration.
481 if (Previous.ClosesTemplateDeclaration && CurrentState.BreakBeforeParameter &&
482 Current.CanBreakBefore) {
483 return true;
484 }
485
486 if (State.Line->First->isNot(tok::kw_enum) && State.Column <= NewLineColumn)
487 return false;
488
489 if (Style.AlwaysBreakBeforeMultilineStrings &&
490 (NewLineColumn == State.FirstIndent + Style.ContinuationIndentWidth ||
491 Previous.is(tok::comma) || Current.NestingLevel < 2) &&
492 !Previous.isOneOf(tok::kw_return, tok::lessless, tok::at,
493 Keywords.kw_dollar) &&
494 !Previous.isOneOf(TT_InlineASMColon, TT_ConditionalExpr) &&
495 nextIsMultilineString(State)) {
496 return true;
497 }
498
499 // Using CanBreakBefore here and below takes care of the decision whether the
500 // current style uses wrapping before or after operators for the given
501 // operator.
502 if (Previous.is(TT_BinaryOperator) && Current.CanBreakBefore) {
503 const auto PreviousPrecedence = Previous.getPrecedence();
504 if (PreviousPrecedence != prec::Assignment &&
505 CurrentState.BreakBeforeParameter && !Current.isTrailingComment()) {
506 const bool LHSIsBinaryExpr =
507 Previous.Previous && Previous.Previous->EndsBinaryExpression;
508 if (LHSIsBinaryExpr)
509 return true;
510 // If we need to break somewhere inside the LHS of a binary expression, we
511 // should also break after the operator. Otherwise, the formatting would
512 // hide the operator precedence, e.g. in:
513 // if (aaaaaaaaaaaaaa ==
514 // bbbbbbbbbbbbbb && c) {..
515 // For comparisons, we only apply this rule, if the LHS is a binary
516 // expression itself as otherwise, the line breaks seem superfluous.
517 // We need special cases for ">>" which we have split into two ">" while
518 // lexing in order to make template parsing easier.
519 const bool IsComparison =
520 (PreviousPrecedence == prec::Relational ||
521 PreviousPrecedence == prec::Equality ||
522 PreviousPrecedence == prec::Spaceship) &&
523 Previous.Previous &&
524 Previous.Previous->isNot(TT_BinaryOperator); // For >>.
525 if (!IsComparison)
526 return true;
527 }
528 } else if (Current.is(TT_BinaryOperator) && Current.CanBreakBefore &&
529 CurrentState.BreakBeforeParameter) {
530 return true;
531 }
532
533 // Same as above, but for the first "<<" operator.
534 if (Current.is(tok::lessless) && Current.isNot(TT_OverloadedOperator) &&
535 CurrentState.BreakBeforeParameter && CurrentState.FirstLessLess == 0) {
536 return true;
537 }
538
539 if (Current.NestingLevel == 0 && !Current.isTrailingComment()) {
540 // Always break after "template <...>"(*) and leading annotations. This is
541 // only for cases where the entire line does not fit on a single line as a
542 // different LineFormatter would be used otherwise.
543 // *: Except when another option interferes with that, like concepts.
544 if (Previous.ClosesTemplateDeclaration) {
545 if (Current.is(tok::kw_concept)) {
546 switch (Style.BreakBeforeConceptDeclarations) {
547 case FormatStyle::BBCDS_Allowed:
548 break;
549 case FormatStyle::BBCDS_Always:
550 return true;
551 case FormatStyle::BBCDS_Never:
552 return false;
553 }
554 }
555 if (Current.is(TT_RequiresClause)) {
556 switch (Style.RequiresClausePosition) {
557 case FormatStyle::RCPS_SingleLine:
558 case FormatStyle::RCPS_WithPreceding:
559 return false;
560 default:
561 return true;
562 }
563 }
564 return Style.AlwaysBreakTemplateDeclarations != FormatStyle::BTDS_No;
565 }
566 if (Previous.is(TT_FunctionAnnotationRParen) &&
567 State.Line->Type != LT_PreprocessorDirective) {
568 return true;
569 }
570 if (Previous.is(TT_LeadingJavaAnnotation) && Current.isNot(tok::l_paren) &&
571 Current.isNot(TT_LeadingJavaAnnotation)) {
572 return true;
573 }
574 }
575
576 if (Style.isJavaScript() && Previous.is(tok::r_paren) &&
577 Previous.is(TT_JavaAnnotation)) {
578 // Break after the closing parenthesis of TypeScript decorators before
579 // functions, getters and setters.
580 static const llvm::StringSet<> BreakBeforeDecoratedTokens = {"get", "set",
581 "function"};
582 if (BreakBeforeDecoratedTokens.contains(Current.TokenText))
583 return true;
584 }
585
586 if (Current.is(TT_FunctionDeclarationName) &&
587 !State.Line->ReturnTypeWrapped &&
588 // Don't break before a C# function when no break after return type.
589 (!Style.isCSharp() ||
590 Style.AlwaysBreakAfterReturnType != FormatStyle::RTBS_None) &&
591 // Don't always break between a JavaScript `function` and the function
592 // name.
593 !Style.isJavaScript() && Previous.isNot(tok::kw_template) &&
594 CurrentState.BreakBeforeParameter) {
595 return true;
596 }
597
598 // The following could be precomputed as they do not depend on the state.
599 // However, as they should take effect only if the UnwrappedLine does not fit
600 // into the ColumnLimit, they are checked here in the ContinuationIndenter.
601 if (Style.ColumnLimit != 0 && Previous.is(BK_Block) &&
602 Previous.is(tok::l_brace) &&
603 !Current.isOneOf(tok::r_brace, tok::comment)) {
604 return true;
605 }
606
607 if (Current.is(tok::lessless) &&
608 ((Previous.is(tok::identifier) && Previous.TokenText == "endl") ||
609 (Previous.Tok.isLiteral() && (Previous.TokenText.ends_with("\\n\"") ||
610 Previous.TokenText == "\'\\n\'")))) {
611 return true;
612 }
613
614 if (Previous.is(TT_BlockComment) && Previous.IsMultiline)
615 return true;
616
617 if (State.NoContinuation)
618 return true;
619
620 return false;
621 }
622
addTokenToState(LineState & State,bool Newline,bool DryRun,unsigned ExtraSpaces)623 unsigned ContinuationIndenter::addTokenToState(LineState &State, bool Newline,
624 bool DryRun,
625 unsigned ExtraSpaces) {
626 const FormatToken &Current = *State.NextToken;
627 assert(State.NextToken->Previous);
628 const FormatToken &Previous = *State.NextToken->Previous;
629
630 assert(!State.Stack.empty());
631 State.NoContinuation = false;
632
633 if (Current.is(TT_ImplicitStringLiteral) &&
634 (!Previous.Tok.getIdentifierInfo() ||
635 Previous.Tok.getIdentifierInfo()->getPPKeywordID() ==
636 tok::pp_not_keyword)) {
637 unsigned EndColumn =
638 SourceMgr.getSpellingColumnNumber(Current.WhitespaceRange.getEnd());
639 if (Current.LastNewlineOffset != 0) {
640 // If there is a newline within this token, the final column will solely
641 // determined by the current end column.
642 State.Column = EndColumn;
643 } else {
644 unsigned StartColumn =
645 SourceMgr.getSpellingColumnNumber(Current.WhitespaceRange.getBegin());
646 assert(EndColumn >= StartColumn);
647 State.Column += EndColumn - StartColumn;
648 }
649 moveStateToNextToken(State, DryRun, /*Newline=*/false);
650 return 0;
651 }
652
653 unsigned Penalty = 0;
654 if (Newline)
655 Penalty = addTokenOnNewLine(State, DryRun);
656 else
657 addTokenOnCurrentLine(State, DryRun, ExtraSpaces);
658
659 return moveStateToNextToken(State, DryRun, Newline) + Penalty;
660 }
661
addTokenOnCurrentLine(LineState & State,bool DryRun,unsigned ExtraSpaces)662 void ContinuationIndenter::addTokenOnCurrentLine(LineState &State, bool DryRun,
663 unsigned ExtraSpaces) {
664 FormatToken &Current = *State.NextToken;
665 assert(State.NextToken->Previous);
666 const FormatToken &Previous = *State.NextToken->Previous;
667 auto &CurrentState = State.Stack.back();
668
669 bool DisallowLineBreaksOnThisLine =
670 Style.LambdaBodyIndentation == FormatStyle::LBI_Signature &&
671 Style.isCpp() && [&Current] {
672 // Deal with lambda arguments in C++. The aim here is to ensure that we
673 // don't over-indent lambda function bodies when lambdas are passed as
674 // arguments to function calls. We do this by ensuring that either all
675 // arguments (including any lambdas) go on the same line as the function
676 // call, or we break before the first argument.
677 const auto *Prev = Current.Previous;
678 if (!Prev)
679 return false;
680 // For example, `/*Newline=*/false`.
681 if (Prev->is(TT_BlockComment) && Current.SpacesRequiredBefore == 0)
682 return false;
683 const auto *PrevNonComment = Current.getPreviousNonComment();
684 if (!PrevNonComment || PrevNonComment->isNot(tok::l_paren))
685 return false;
686 if (Current.isOneOf(tok::comment, tok::l_paren, TT_LambdaLSquare))
687 return false;
688 auto BlockParameterCount = PrevNonComment->BlockParameterCount;
689 if (BlockParameterCount == 0)
690 return false;
691
692 // Multiple lambdas in the same function call.
693 if (BlockParameterCount > 1)
694 return true;
695
696 // A lambda followed by another arg.
697 if (!PrevNonComment->Role)
698 return false;
699 auto Comma = PrevNonComment->Role->lastComma();
700 if (!Comma)
701 return false;
702 auto Next = Comma->getNextNonComment();
703 return Next &&
704 !Next->isOneOf(TT_LambdaLSquare, tok::l_brace, tok::caret);
705 }();
706
707 if (DisallowLineBreaksOnThisLine)
708 State.NoLineBreak = true;
709
710 if (Current.is(tok::equal) &&
711 (State.Line->First->is(tok::kw_for) || Current.NestingLevel == 0) &&
712 CurrentState.VariablePos == 0 &&
713 (!Previous.Previous ||
714 Previous.Previous->isNot(TT_DesignatedInitializerPeriod))) {
715 CurrentState.VariablePos = State.Column;
716 // Move over * and & if they are bound to the variable name.
717 const FormatToken *Tok = &Previous;
718 while (Tok && CurrentState.VariablePos >= Tok->ColumnWidth) {
719 CurrentState.VariablePos -= Tok->ColumnWidth;
720 if (Tok->SpacesRequiredBefore != 0)
721 break;
722 Tok = Tok->Previous;
723 }
724 if (Previous.PartOfMultiVariableDeclStmt)
725 CurrentState.LastSpace = CurrentState.VariablePos;
726 }
727
728 unsigned Spaces = Current.SpacesRequiredBefore + ExtraSpaces;
729
730 // Indent preprocessor directives after the hash if required.
731 int PPColumnCorrection = 0;
732 if (Style.IndentPPDirectives == FormatStyle::PPDIS_AfterHash &&
733 Previous.is(tok::hash) && State.FirstIndent > 0 &&
734 &Previous == State.Line->First &&
735 (State.Line->Type == LT_PreprocessorDirective ||
736 State.Line->Type == LT_ImportStatement)) {
737 Spaces += State.FirstIndent;
738
739 // For preprocessor indent with tabs, State.Column will be 1 because of the
740 // hash. This causes second-level indents onward to have an extra space
741 // after the tabs. We avoid this misalignment by subtracting 1 from the
742 // column value passed to replaceWhitespace().
743 if (Style.UseTab != FormatStyle::UT_Never)
744 PPColumnCorrection = -1;
745 }
746
747 if (!DryRun) {
748 Whitespaces.replaceWhitespace(Current, /*Newlines=*/0, Spaces,
749 State.Column + Spaces + PPColumnCorrection,
750 /*IsAligned=*/false, State.Line->InMacroBody);
751 }
752
753 // If "BreakBeforeInheritanceComma" mode, don't break within the inheritance
754 // declaration unless there is multiple inheritance.
755 if (Style.BreakInheritanceList == FormatStyle::BILS_BeforeComma &&
756 Current.is(TT_InheritanceColon)) {
757 CurrentState.NoLineBreak = true;
758 }
759 if (Style.BreakInheritanceList == FormatStyle::BILS_AfterColon &&
760 Previous.is(TT_InheritanceColon)) {
761 CurrentState.NoLineBreak = true;
762 }
763
764 if (Current.is(TT_SelectorName) && !CurrentState.ObjCSelectorNameFound) {
765 unsigned MinIndent = std::max(
766 State.FirstIndent + Style.ContinuationIndentWidth, CurrentState.Indent);
767 unsigned FirstColonPos = State.Column + Spaces + Current.ColumnWidth;
768 if (Current.LongestObjCSelectorName == 0)
769 CurrentState.AlignColons = false;
770 else if (MinIndent + Current.LongestObjCSelectorName > FirstColonPos)
771 CurrentState.ColonPos = MinIndent + Current.LongestObjCSelectorName;
772 else
773 CurrentState.ColonPos = FirstColonPos;
774 }
775
776 // In "AlwaysBreak" or "BlockIndent" mode, enforce wrapping directly after the
777 // parenthesis by disallowing any further line breaks if there is no line
778 // break after the opening parenthesis. Don't break if it doesn't conserve
779 // columns.
780 auto IsOpeningBracket = [&](const FormatToken &Tok) {
781 auto IsStartOfBracedList = [&]() {
782 return Tok.is(tok::l_brace) && Tok.isNot(BK_Block) &&
783 Style.Cpp11BracedListStyle;
784 };
785 if (!Tok.isOneOf(tok::l_paren, TT_TemplateOpener, tok::l_square) &&
786 !IsStartOfBracedList()) {
787 return false;
788 }
789 if (!Tok.Previous)
790 return true;
791 if (Tok.Previous->isIf())
792 return Style.AlignAfterOpenBracket == FormatStyle::BAS_AlwaysBreak;
793 return !Tok.Previous->isOneOf(TT_CastRParen, tok::kw_for, tok::kw_while,
794 tok::kw_switch);
795 };
796 if ((Style.AlignAfterOpenBracket == FormatStyle::BAS_AlwaysBreak ||
797 Style.AlignAfterOpenBracket == FormatStyle::BAS_BlockIndent) &&
798 IsOpeningBracket(Previous) && State.Column > getNewLineColumn(State) &&
799 // Don't do this for simple (no expressions) one-argument function calls
800 // as that feels like needlessly wasting whitespace, e.g.:
801 //
802 // caaaaaaaaaaaall(
803 // caaaaaaaaaaaall(
804 // caaaaaaaaaaaall(
805 // caaaaaaaaaaaaaaaaaaaaaaall(aaaaaaaaaaaaaa, aaaaaaaaa))));
806 Current.FakeLParens.size() > 0 &&
807 Current.FakeLParens.back() > prec::Unknown) {
808 CurrentState.NoLineBreak = true;
809 }
810 if (Previous.is(TT_TemplateString) && Previous.opensScope())
811 CurrentState.NoLineBreak = true;
812
813 // Align following lines within parentheses / brackets if configured.
814 // Note: This doesn't apply to macro expansion lines, which are MACRO( , , )
815 // with args as children of the '(' and ',' tokens. It does not make sense to
816 // align the commas with the opening paren.
817 if (Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign &&
818 !CurrentState.IsCSharpGenericTypeConstraint && Previous.opensScope() &&
819 Previous.isNot(TT_ObjCMethodExpr) && Previous.isNot(TT_RequiresClause) &&
820 !(Current.MacroParent && Previous.MacroParent) &&
821 (Current.isNot(TT_LineComment) ||
822 Previous.isOneOf(BK_BracedInit, TT_VerilogMultiLineListLParen))) {
823 CurrentState.Indent = State.Column + Spaces;
824 CurrentState.IsAligned = true;
825 }
826 if (CurrentState.AvoidBinPacking && startsNextParameter(Current, Style))
827 CurrentState.NoLineBreak = true;
828 if (startsSegmentOfBuilderTypeCall(Current) &&
829 State.Column > getNewLineColumn(State)) {
830 CurrentState.ContainsUnwrappedBuilder = true;
831 }
832
833 if (Current.is(TT_TrailingReturnArrow) &&
834 Style.Language == FormatStyle::LK_Java) {
835 CurrentState.NoLineBreak = true;
836 }
837 if (Current.isMemberAccess() && Previous.is(tok::r_paren) &&
838 (Previous.MatchingParen &&
839 (Previous.TotalLength - Previous.MatchingParen->TotalLength > 10))) {
840 // If there is a function call with long parameters, break before trailing
841 // calls. This prevents things like:
842 // EXPECT_CALL(SomeLongParameter).Times(
843 // 2);
844 // We don't want to do this for short parameters as they can just be
845 // indexes.
846 CurrentState.NoLineBreak = true;
847 }
848
849 // Don't allow the RHS of an operator to be split over multiple lines unless
850 // there is a line-break right after the operator.
851 // Exclude relational operators, as there, it is always more desirable to
852 // have the LHS 'left' of the RHS.
853 const FormatToken *P = Current.getPreviousNonComment();
854 if (Current.isNot(tok::comment) && P &&
855 (P->isOneOf(TT_BinaryOperator, tok::comma) ||
856 (P->is(TT_ConditionalExpr) && P->is(tok::colon))) &&
857 !P->isOneOf(TT_OverloadedOperator, TT_CtorInitializerComma) &&
858 P->getPrecedence() != prec::Assignment &&
859 P->getPrecedence() != prec::Relational &&
860 P->getPrecedence() != prec::Spaceship) {
861 bool BreakBeforeOperator =
862 P->MustBreakBefore || P->is(tok::lessless) ||
863 (P->is(TT_BinaryOperator) &&
864 Style.BreakBeforeBinaryOperators != FormatStyle::BOS_None) ||
865 (P->is(TT_ConditionalExpr) && Style.BreakBeforeTernaryOperators);
866 // Don't do this if there are only two operands. In these cases, there is
867 // always a nice vertical separation between them and the extra line break
868 // does not help.
869 bool HasTwoOperands = P->OperatorIndex == 0 && !P->NextOperator &&
870 P->isNot(TT_ConditionalExpr);
871 if ((!BreakBeforeOperator &&
872 !(HasTwoOperands &&
873 Style.AlignOperands != FormatStyle::OAS_DontAlign)) ||
874 (!CurrentState.LastOperatorWrapped && BreakBeforeOperator)) {
875 CurrentState.NoLineBreakInOperand = true;
876 }
877 }
878
879 State.Column += Spaces;
880 if (Current.isNot(tok::comment) && Previous.is(tok::l_paren) &&
881 Previous.Previous &&
882 (Previous.Previous->is(tok::kw_for) || Previous.Previous->isIf())) {
883 // Treat the condition inside an if as if it was a second function
884 // parameter, i.e. let nested calls have a continuation indent.
885 CurrentState.LastSpace = State.Column;
886 CurrentState.NestedBlockIndent = State.Column;
887 } else if (!Current.isOneOf(tok::comment, tok::caret) &&
888 ((Previous.is(tok::comma) &&
889 Previous.isNot(TT_OverloadedOperator)) ||
890 (Previous.is(tok::colon) && Previous.is(TT_ObjCMethodExpr)))) {
891 CurrentState.LastSpace = State.Column;
892 } else if (Previous.is(TT_CtorInitializerColon) &&
893 (!Current.isTrailingComment() || Current.NewlinesBefore > 0) &&
894 Style.BreakConstructorInitializers ==
895 FormatStyle::BCIS_AfterColon) {
896 CurrentState.Indent = State.Column;
897 CurrentState.LastSpace = State.Column;
898 } else if (Previous.isOneOf(TT_ConditionalExpr, TT_CtorInitializerColon)) {
899 CurrentState.LastSpace = State.Column;
900 } else if (Previous.is(TT_BinaryOperator) &&
901 ((Previous.getPrecedence() != prec::Assignment &&
902 (Previous.isNot(tok::lessless) || Previous.OperatorIndex != 0 ||
903 Previous.NextOperator)) ||
904 Current.StartsBinaryExpression)) {
905 // Indent relative to the RHS of the expression unless this is a simple
906 // assignment without binary expression on the RHS.
907 if (Style.BreakBeforeBinaryOperators == FormatStyle::BOS_None)
908 CurrentState.LastSpace = State.Column;
909 } else if (Previous.is(TT_InheritanceColon)) {
910 CurrentState.Indent = State.Column;
911 CurrentState.LastSpace = State.Column;
912 } else if (Current.is(TT_CSharpGenericTypeConstraintColon)) {
913 CurrentState.ColonPos = State.Column;
914 } else if (Previous.opensScope()) {
915 // If a function has a trailing call, indent all parameters from the
916 // opening parenthesis. This avoids confusing indents like:
917 // OuterFunction(InnerFunctionCall( // break
918 // ParameterToInnerFunction)) // break
919 // .SecondInnerFunctionCall();
920 if (Previous.MatchingParen) {
921 const FormatToken *Next = Previous.MatchingParen->getNextNonComment();
922 if (Next && Next->isMemberAccess() && State.Stack.size() > 1 &&
923 State.Stack[State.Stack.size() - 2].CallContinuation == 0) {
924 CurrentState.LastSpace = State.Column;
925 }
926 }
927 }
928 }
929
addTokenOnNewLine(LineState & State,bool DryRun)930 unsigned ContinuationIndenter::addTokenOnNewLine(LineState &State,
931 bool DryRun) {
932 FormatToken &Current = *State.NextToken;
933 assert(State.NextToken->Previous);
934 const FormatToken &Previous = *State.NextToken->Previous;
935 auto &CurrentState = State.Stack.back();
936
937 // Extra penalty that needs to be added because of the way certain line
938 // breaks are chosen.
939 unsigned Penalty = 0;
940
941 const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
942 const FormatToken *NextNonComment = Previous.getNextNonComment();
943 if (!NextNonComment)
944 NextNonComment = &Current;
945 // The first line break on any NestingLevel causes an extra penalty in order
946 // prefer similar line breaks.
947 if (!CurrentState.ContainsLineBreak)
948 Penalty += 15;
949 CurrentState.ContainsLineBreak = true;
950
951 Penalty += State.NextToken->SplitPenalty;
952
953 // Breaking before the first "<<" is generally not desirable if the LHS is
954 // short. Also always add the penalty if the LHS is split over multiple lines
955 // to avoid unnecessary line breaks that just work around this penalty.
956 if (NextNonComment->is(tok::lessless) && CurrentState.FirstLessLess == 0 &&
957 (State.Column <= Style.ColumnLimit / 3 ||
958 CurrentState.BreakBeforeParameter)) {
959 Penalty += Style.PenaltyBreakFirstLessLess;
960 }
961
962 State.Column = getNewLineColumn(State);
963
964 // Add Penalty proportional to amount of whitespace away from FirstColumn
965 // This tends to penalize several lines that are far-right indented,
966 // and prefers a line-break prior to such a block, e.g:
967 //
968 // Constructor() :
969 // member(value), looooooooooooooooong_member(
970 // looooooooooong_call(param_1, param_2, param_3))
971 // would then become
972 // Constructor() :
973 // member(value),
974 // looooooooooooooooong_member(
975 // looooooooooong_call(param_1, param_2, param_3))
976 if (State.Column > State.FirstIndent) {
977 Penalty +=
978 Style.PenaltyIndentedWhitespace * (State.Column - State.FirstIndent);
979 }
980
981 // Indent nested blocks relative to this column, unless in a very specific
982 // JavaScript special case where:
983 //
984 // var loooooong_name =
985 // function() {
986 // // code
987 // }
988 //
989 // is common and should be formatted like a free-standing function. The same
990 // goes for wrapping before the lambda return type arrow.
991 if (Current.isNot(TT_TrailingReturnArrow) &&
992 (!Style.isJavaScript() || Current.NestingLevel != 0 ||
993 !PreviousNonComment || PreviousNonComment->isNot(tok::equal) ||
994 !Current.isOneOf(Keywords.kw_async, Keywords.kw_function))) {
995 CurrentState.NestedBlockIndent = State.Column;
996 }
997
998 if (NextNonComment->isMemberAccess()) {
999 if (CurrentState.CallContinuation == 0)
1000 CurrentState.CallContinuation = State.Column;
1001 } else if (NextNonComment->is(TT_SelectorName)) {
1002 if (!CurrentState.ObjCSelectorNameFound) {
1003 if (NextNonComment->LongestObjCSelectorName == 0) {
1004 CurrentState.AlignColons = false;
1005 } else {
1006 CurrentState.ColonPos =
1007 (shouldIndentWrappedSelectorName(Style, State.Line->Type)
1008 ? std::max(CurrentState.Indent,
1009 State.FirstIndent + Style.ContinuationIndentWidth)
1010 : CurrentState.Indent) +
1011 std::max(NextNonComment->LongestObjCSelectorName,
1012 NextNonComment->ColumnWidth);
1013 }
1014 } else if (CurrentState.AlignColons &&
1015 CurrentState.ColonPos <= NextNonComment->ColumnWidth) {
1016 CurrentState.ColonPos = State.Column + NextNonComment->ColumnWidth;
1017 }
1018 } else if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
1019 PreviousNonComment->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral)) {
1020 // FIXME: This is hacky, find a better way. The problem is that in an ObjC
1021 // method expression, the block should be aligned to the line starting it,
1022 // e.g.:
1023 // [aaaaaaaaaaaaaaa aaaaaaaaa: \\ break for some reason
1024 // ^(int *i) {
1025 // // ...
1026 // }];
1027 // Thus, we set LastSpace of the next higher NestingLevel, to which we move
1028 // when we consume all of the "}"'s FakeRParens at the "{".
1029 if (State.Stack.size() > 1) {
1030 State.Stack[State.Stack.size() - 2].LastSpace =
1031 std::max(CurrentState.LastSpace, CurrentState.Indent) +
1032 Style.ContinuationIndentWidth;
1033 }
1034 }
1035
1036 if ((PreviousNonComment &&
1037 PreviousNonComment->isOneOf(tok::comma, tok::semi) &&
1038 !CurrentState.AvoidBinPacking) ||
1039 Previous.is(TT_BinaryOperator)) {
1040 CurrentState.BreakBeforeParameter = false;
1041 }
1042 if (PreviousNonComment &&
1043 (PreviousNonComment->isOneOf(TT_TemplateCloser, TT_JavaAnnotation) ||
1044 PreviousNonComment->ClosesRequiresClause) &&
1045 Current.NestingLevel == 0) {
1046 CurrentState.BreakBeforeParameter = false;
1047 }
1048 if (NextNonComment->is(tok::question) ||
1049 (PreviousNonComment && PreviousNonComment->is(tok::question))) {
1050 CurrentState.BreakBeforeParameter = true;
1051 }
1052 if (Current.is(TT_BinaryOperator) && Current.CanBreakBefore)
1053 CurrentState.BreakBeforeParameter = false;
1054
1055 if (!DryRun) {
1056 unsigned MaxEmptyLinesToKeep = Style.MaxEmptyLinesToKeep + 1;
1057 if (Current.is(tok::r_brace) && Current.MatchingParen &&
1058 // Only strip trailing empty lines for l_braces that have children, i.e.
1059 // for function expressions (lambdas, arrows, etc).
1060 !Current.MatchingParen->Children.empty()) {
1061 // lambdas and arrow functions are expressions, thus their r_brace is not
1062 // on its own line, and thus not covered by UnwrappedLineFormatter's logic
1063 // about removing empty lines on closing blocks. Special case them here.
1064 MaxEmptyLinesToKeep = 1;
1065 }
1066 unsigned Newlines =
1067 std::max(1u, std::min(Current.NewlinesBefore, MaxEmptyLinesToKeep));
1068 bool ContinuePPDirective =
1069 State.Line->InPPDirective && State.Line->Type != LT_ImportStatement;
1070 Whitespaces.replaceWhitespace(Current, Newlines, State.Column, State.Column,
1071 CurrentState.IsAligned, ContinuePPDirective);
1072 }
1073
1074 if (!Current.isTrailingComment())
1075 CurrentState.LastSpace = State.Column;
1076 if (Current.is(tok::lessless)) {
1077 // If we are breaking before a "<<", we always want to indent relative to
1078 // RHS. This is necessary only for "<<", as we special-case it and don't
1079 // always indent relative to the RHS.
1080 CurrentState.LastSpace += 3; // 3 -> width of "<< ".
1081 }
1082
1083 State.StartOfLineLevel = Current.NestingLevel;
1084 State.LowestLevelOnLine = Current.NestingLevel;
1085
1086 // Any break on this level means that the parent level has been broken
1087 // and we need to avoid bin packing there.
1088 bool NestedBlockSpecialCase =
1089 (!Style.isCpp() && Current.is(tok::r_brace) && State.Stack.size() > 1 &&
1090 State.Stack[State.Stack.size() - 2].NestedBlockInlined) ||
1091 (Style.Language == FormatStyle::LK_ObjC && Current.is(tok::r_brace) &&
1092 State.Stack.size() > 1 && !Style.ObjCBreakBeforeNestedBlockParam);
1093 // Do not force parameter break for statements with requires expressions.
1094 NestedBlockSpecialCase =
1095 NestedBlockSpecialCase ||
1096 (Current.MatchingParen &&
1097 Current.MatchingParen->is(TT_RequiresExpressionLBrace));
1098 if (!NestedBlockSpecialCase) {
1099 auto ParentLevelIt = std::next(State.Stack.rbegin());
1100 if (Style.LambdaBodyIndentation == FormatStyle::LBI_OuterScope &&
1101 Current.MatchingParen && Current.MatchingParen->is(TT_LambdaLBrace)) {
1102 // If the first character on the new line is a lambda's closing brace, the
1103 // stack still contains that lambda's parenthesis. As such, we need to
1104 // recurse further down the stack than usual to find the parenthesis level
1105 // containing the lambda, which is where we want to set
1106 // BreakBeforeParameter.
1107 //
1108 // We specifically special case "OuterScope"-formatted lambdas here
1109 // because, when using that setting, breaking before the parameter
1110 // directly following the lambda is particularly unsightly. However, when
1111 // "OuterScope" is not set, the logic to find the parent parenthesis level
1112 // still appears to be sometimes incorrect. It has not been fixed yet
1113 // because it would lead to significant changes in existing behaviour.
1114 //
1115 // TODO: fix the non-"OuterScope" case too.
1116 auto FindCurrentLevel = [&](const auto &It) {
1117 return std::find_if(It, State.Stack.rend(), [](const auto &PState) {
1118 return PState.Tok != nullptr; // Ignore fake parens.
1119 });
1120 };
1121 auto MaybeIncrement = [&](const auto &It) {
1122 return It != State.Stack.rend() ? std::next(It) : It;
1123 };
1124 auto LambdaLevelIt = FindCurrentLevel(State.Stack.rbegin());
1125 auto LevelContainingLambdaIt =
1126 FindCurrentLevel(MaybeIncrement(LambdaLevelIt));
1127 ParentLevelIt = MaybeIncrement(LevelContainingLambdaIt);
1128 }
1129 for (auto I = ParentLevelIt, E = State.Stack.rend(); I != E; ++I)
1130 I->BreakBeforeParameter = true;
1131 }
1132
1133 if (PreviousNonComment &&
1134 !PreviousNonComment->isOneOf(tok::comma, tok::colon, tok::semi) &&
1135 ((PreviousNonComment->isNot(TT_TemplateCloser) &&
1136 !PreviousNonComment->ClosesRequiresClause) ||
1137 Current.NestingLevel != 0) &&
1138 !PreviousNonComment->isOneOf(
1139 TT_BinaryOperator, TT_FunctionAnnotationRParen, TT_JavaAnnotation,
1140 TT_LeadingJavaAnnotation) &&
1141 Current.isNot(TT_BinaryOperator) && !PreviousNonComment->opensScope() &&
1142 // We don't want to enforce line breaks for subsequent arguments just
1143 // because we have been forced to break before a lambda body.
1144 (!Style.BraceWrapping.BeforeLambdaBody ||
1145 Current.isNot(TT_LambdaLBrace))) {
1146 CurrentState.BreakBeforeParameter = true;
1147 }
1148
1149 // If we break after { or the [ of an array initializer, we should also break
1150 // before the corresponding } or ].
1151 if (PreviousNonComment &&
1152 (PreviousNonComment->isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) ||
1153 opensProtoMessageField(*PreviousNonComment, Style))) {
1154 CurrentState.BreakBeforeClosingBrace = true;
1155 }
1156
1157 if (PreviousNonComment && PreviousNonComment->is(tok::l_paren)) {
1158 CurrentState.BreakBeforeClosingParen =
1159 Style.AlignAfterOpenBracket == FormatStyle::BAS_BlockIndent;
1160 }
1161
1162 if (CurrentState.AvoidBinPacking) {
1163 // If we are breaking after '(', '{', '<', or this is the break after a ':'
1164 // to start a member initializer list in a constructor, this should not
1165 // be considered bin packing unless the relevant AllowAll option is false or
1166 // this is a dict/object literal.
1167 bool PreviousIsBreakingCtorInitializerColon =
1168 PreviousNonComment && PreviousNonComment->is(TT_CtorInitializerColon) &&
1169 Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon;
1170 bool AllowAllConstructorInitializersOnNextLine =
1171 Style.PackConstructorInitializers == FormatStyle::PCIS_NextLine ||
1172 Style.PackConstructorInitializers == FormatStyle::PCIS_NextLineOnly;
1173 if (!(Previous.isOneOf(tok::l_paren, tok::l_brace, TT_BinaryOperator) ||
1174 PreviousIsBreakingCtorInitializerColon) ||
1175 (!Style.AllowAllParametersOfDeclarationOnNextLine &&
1176 State.Line->MustBeDeclaration) ||
1177 (!Style.AllowAllArgumentsOnNextLine &&
1178 !State.Line->MustBeDeclaration) ||
1179 (!AllowAllConstructorInitializersOnNextLine &&
1180 PreviousIsBreakingCtorInitializerColon) ||
1181 Previous.is(TT_DictLiteral)) {
1182 CurrentState.BreakBeforeParameter = true;
1183 }
1184
1185 // If we are breaking after a ':' to start a member initializer list,
1186 // and we allow all arguments on the next line, we should not break
1187 // before the next parameter.
1188 if (PreviousIsBreakingCtorInitializerColon &&
1189 AllowAllConstructorInitializersOnNextLine) {
1190 CurrentState.BreakBeforeParameter = false;
1191 }
1192 }
1193
1194 return Penalty;
1195 }
1196
getNewLineColumn(const LineState & State)1197 unsigned ContinuationIndenter::getNewLineColumn(const LineState &State) {
1198 if (!State.NextToken || !State.NextToken->Previous)
1199 return 0;
1200
1201 FormatToken &Current = *State.NextToken;
1202 const auto &CurrentState = State.Stack.back();
1203
1204 if (CurrentState.IsCSharpGenericTypeConstraint &&
1205 Current.isNot(TT_CSharpGenericTypeConstraint)) {
1206 return CurrentState.ColonPos + 2;
1207 }
1208
1209 const FormatToken &Previous = *Current.Previous;
1210 // If we are continuing an expression, we want to use the continuation indent.
1211 unsigned ContinuationIndent =
1212 std::max(CurrentState.LastSpace, CurrentState.Indent) +
1213 Style.ContinuationIndentWidth;
1214 const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
1215 const FormatToken *NextNonComment = Previous.getNextNonComment();
1216 if (!NextNonComment)
1217 NextNonComment = &Current;
1218
1219 // Java specific bits.
1220 if (Style.Language == FormatStyle::LK_Java &&
1221 Current.isOneOf(Keywords.kw_implements, Keywords.kw_extends)) {
1222 return std::max(CurrentState.LastSpace,
1223 CurrentState.Indent + Style.ContinuationIndentWidth);
1224 }
1225
1226 // Indentation of the statement following a Verilog case label is taken care
1227 // of in moveStateToNextToken.
1228 if (Style.isVerilog() && PreviousNonComment &&
1229 Keywords.isVerilogEndOfLabel(*PreviousNonComment)) {
1230 return State.FirstIndent;
1231 }
1232
1233 if (Style.BreakBeforeBraces == FormatStyle::BS_Whitesmiths &&
1234 State.Line->First->is(tok::kw_enum)) {
1235 return (Style.IndentWidth * State.Line->First->IndentLevel) +
1236 Style.IndentWidth;
1237 }
1238
1239 if ((NextNonComment->is(tok::l_brace) && NextNonComment->is(BK_Block)) ||
1240 (Style.isVerilog() && Keywords.isVerilogBegin(*NextNonComment))) {
1241 if (Current.NestingLevel == 0 ||
1242 (Style.LambdaBodyIndentation == FormatStyle::LBI_OuterScope &&
1243 State.NextToken->is(TT_LambdaLBrace))) {
1244 return State.FirstIndent;
1245 }
1246 return CurrentState.Indent;
1247 }
1248 if ((Current.isOneOf(tok::r_brace, tok::r_square) ||
1249 (Current.is(tok::greater) && Style.isProto())) &&
1250 State.Stack.size() > 1) {
1251 if (Current.closesBlockOrBlockTypeList(Style))
1252 return State.Stack[State.Stack.size() - 2].NestedBlockIndent;
1253 if (Current.MatchingParen && Current.MatchingParen->is(BK_BracedInit))
1254 return State.Stack[State.Stack.size() - 2].LastSpace;
1255 return State.FirstIndent;
1256 }
1257 // Indent a closing parenthesis at the previous level if followed by a semi,
1258 // const, or opening brace. This allows indentations such as:
1259 // foo(
1260 // a,
1261 // );
1262 // int Foo::getter(
1263 // //
1264 // ) const {
1265 // return foo;
1266 // }
1267 // function foo(
1268 // a,
1269 // ) {
1270 // code(); //
1271 // }
1272 if (Current.is(tok::r_paren) && State.Stack.size() > 1 &&
1273 (!Current.Next ||
1274 Current.Next->isOneOf(tok::semi, tok::kw_const, tok::l_brace))) {
1275 return State.Stack[State.Stack.size() - 2].LastSpace;
1276 }
1277 if (Style.AlignAfterOpenBracket == FormatStyle::BAS_BlockIndent &&
1278 (Current.is(tok::r_paren) ||
1279 (Current.is(tok::r_brace) && Current.MatchingParen &&
1280 Current.MatchingParen->is(BK_BracedInit))) &&
1281 State.Stack.size() > 1) {
1282 return State.Stack[State.Stack.size() - 2].LastSpace;
1283 }
1284 if (NextNonComment->is(TT_TemplateString) && NextNonComment->closesScope())
1285 return State.Stack[State.Stack.size() - 2].LastSpace;
1286 // Field labels in a nested type should be aligned to the brace. For example
1287 // in ProtoBuf:
1288 // optional int32 b = 2 [(foo_options) = {aaaaaaaaaaaaaaaaaaa: 123,
1289 // bbbbbbbbbbbbbbbbbbbbbbbb:"baz"}];
1290 // For Verilog, a quote following a brace is treated as an identifier. And
1291 // Both braces and colons get annotated as TT_DictLiteral. So we have to
1292 // check.
1293 if (Current.is(tok::identifier) && Current.Next &&
1294 (!Style.isVerilog() || Current.Next->is(tok::colon)) &&
1295 (Current.Next->is(TT_DictLiteral) ||
1296 (Style.isProto() && Current.Next->isOneOf(tok::less, tok::l_brace)))) {
1297 return CurrentState.Indent;
1298 }
1299 if (NextNonComment->is(TT_ObjCStringLiteral) &&
1300 State.StartOfStringLiteral != 0) {
1301 return State.StartOfStringLiteral - 1;
1302 }
1303 if (NextNonComment->isStringLiteral() && State.StartOfStringLiteral != 0)
1304 return State.StartOfStringLiteral;
1305 if (NextNonComment->is(tok::lessless) && CurrentState.FirstLessLess != 0)
1306 return CurrentState.FirstLessLess;
1307 if (NextNonComment->isMemberAccess()) {
1308 if (CurrentState.CallContinuation == 0)
1309 return ContinuationIndent;
1310 return CurrentState.CallContinuation;
1311 }
1312 if (CurrentState.QuestionColumn != 0 &&
1313 ((NextNonComment->is(tok::colon) &&
1314 NextNonComment->is(TT_ConditionalExpr)) ||
1315 Previous.is(TT_ConditionalExpr))) {
1316 if (((NextNonComment->is(tok::colon) && NextNonComment->Next &&
1317 !NextNonComment->Next->FakeLParens.empty() &&
1318 NextNonComment->Next->FakeLParens.back() == prec::Conditional) ||
1319 (Previous.is(tok::colon) && !Current.FakeLParens.empty() &&
1320 Current.FakeLParens.back() == prec::Conditional)) &&
1321 !CurrentState.IsWrappedConditional) {
1322 // NOTE: we may tweak this slightly:
1323 // * not remove the 'lead' ContinuationIndentWidth
1324 // * always un-indent by the operator when
1325 // BreakBeforeTernaryOperators=true
1326 unsigned Indent = CurrentState.Indent;
1327 if (Style.AlignOperands != FormatStyle::OAS_DontAlign)
1328 Indent -= Style.ContinuationIndentWidth;
1329 if (Style.BreakBeforeTernaryOperators && CurrentState.UnindentOperator)
1330 Indent -= 2;
1331 return Indent;
1332 }
1333 return CurrentState.QuestionColumn;
1334 }
1335 if (Previous.is(tok::comma) && CurrentState.VariablePos != 0)
1336 return CurrentState.VariablePos;
1337 if (Current.is(TT_RequiresClause)) {
1338 if (Style.IndentRequiresClause)
1339 return CurrentState.Indent + Style.IndentWidth;
1340 switch (Style.RequiresClausePosition) {
1341 case FormatStyle::RCPS_OwnLine:
1342 case FormatStyle::RCPS_WithFollowing:
1343 return CurrentState.Indent;
1344 default:
1345 break;
1346 }
1347 }
1348 if (NextNonComment->isOneOf(TT_CtorInitializerColon, TT_InheritanceColon,
1349 TT_InheritanceComma)) {
1350 return State.FirstIndent + Style.ConstructorInitializerIndentWidth;
1351 }
1352 if ((PreviousNonComment &&
1353 (PreviousNonComment->ClosesTemplateDeclaration ||
1354 PreviousNonComment->ClosesRequiresClause ||
1355 (PreviousNonComment->is(TT_AttributeMacro) &&
1356 Current.isNot(tok::l_paren)) ||
1357 PreviousNonComment->isOneOf(
1358 TT_AttributeRParen, TT_AttributeSquare, TT_FunctionAnnotationRParen,
1359 TT_JavaAnnotation, TT_LeadingJavaAnnotation))) ||
1360 (!Style.IndentWrappedFunctionNames &&
1361 NextNonComment->isOneOf(tok::kw_operator, TT_FunctionDeclarationName))) {
1362 return std::max(CurrentState.LastSpace, CurrentState.Indent);
1363 }
1364 if (NextNonComment->is(TT_SelectorName)) {
1365 if (!CurrentState.ObjCSelectorNameFound) {
1366 unsigned MinIndent = CurrentState.Indent;
1367 if (shouldIndentWrappedSelectorName(Style, State.Line->Type)) {
1368 MinIndent = std::max(MinIndent,
1369 State.FirstIndent + Style.ContinuationIndentWidth);
1370 }
1371 // If LongestObjCSelectorName is 0, we are indenting the first
1372 // part of an ObjC selector (or a selector component which is
1373 // not colon-aligned due to block formatting).
1374 //
1375 // Otherwise, we are indenting a subsequent part of an ObjC
1376 // selector which should be colon-aligned to the longest
1377 // component of the ObjC selector.
1378 //
1379 // In either case, we want to respect Style.IndentWrappedFunctionNames.
1380 return MinIndent +
1381 std::max(NextNonComment->LongestObjCSelectorName,
1382 NextNonComment->ColumnWidth) -
1383 NextNonComment->ColumnWidth;
1384 }
1385 if (!CurrentState.AlignColons)
1386 return CurrentState.Indent;
1387 if (CurrentState.ColonPos > NextNonComment->ColumnWidth)
1388 return CurrentState.ColonPos - NextNonComment->ColumnWidth;
1389 return CurrentState.Indent;
1390 }
1391 if (NextNonComment->is(tok::colon) && NextNonComment->is(TT_ObjCMethodExpr))
1392 return CurrentState.ColonPos;
1393 if (NextNonComment->is(TT_ArraySubscriptLSquare)) {
1394 if (CurrentState.StartOfArraySubscripts != 0) {
1395 return CurrentState.StartOfArraySubscripts;
1396 } else if (Style.isCSharp()) { // C# allows `["key"] = value` inside object
1397 // initializers.
1398 return CurrentState.Indent;
1399 }
1400 return ContinuationIndent;
1401 }
1402
1403 // OpenMP clauses want to get additional indentation when they are pushed onto
1404 // the next line.
1405 if (State.Line->InPragmaDirective) {
1406 FormatToken *PragmaType = State.Line->First->Next->Next;
1407 if (PragmaType && PragmaType->TokenText.equals("omp"))
1408 return CurrentState.Indent + Style.ContinuationIndentWidth;
1409 }
1410
1411 // This ensure that we correctly format ObjC methods calls without inputs,
1412 // i.e. where the last element isn't selector like: [callee method];
1413 if (NextNonComment->is(tok::identifier) && NextNonComment->FakeRParens == 0 &&
1414 NextNonComment->Next && NextNonComment->Next->is(TT_ObjCMethodExpr)) {
1415 return CurrentState.Indent;
1416 }
1417
1418 if (NextNonComment->isOneOf(TT_StartOfName, TT_PointerOrReference) ||
1419 Previous.isOneOf(tok::coloncolon, tok::equal, TT_JsTypeColon)) {
1420 return ContinuationIndent;
1421 }
1422 if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
1423 PreviousNonComment->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral)) {
1424 return ContinuationIndent;
1425 }
1426 if (NextNonComment->is(TT_CtorInitializerComma))
1427 return CurrentState.Indent;
1428 if (PreviousNonComment && PreviousNonComment->is(TT_CtorInitializerColon) &&
1429 Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon) {
1430 return CurrentState.Indent;
1431 }
1432 if (PreviousNonComment && PreviousNonComment->is(TT_InheritanceColon) &&
1433 Style.BreakInheritanceList == FormatStyle::BILS_AfterColon) {
1434 return CurrentState.Indent;
1435 }
1436 if (Previous.is(tok::r_paren) && !Current.isBinaryOperator() &&
1437 !Current.isOneOf(tok::colon, tok::comment)) {
1438 return ContinuationIndent;
1439 }
1440 if (Current.is(TT_ProtoExtensionLSquare))
1441 return CurrentState.Indent;
1442 if (Current.isBinaryOperator() && CurrentState.UnindentOperator) {
1443 return CurrentState.Indent - Current.Tok.getLength() -
1444 Current.SpacesRequiredBefore;
1445 }
1446 if (Current.is(tok::comment) && NextNonComment->isBinaryOperator() &&
1447 CurrentState.UnindentOperator) {
1448 return CurrentState.Indent - NextNonComment->Tok.getLength() -
1449 NextNonComment->SpacesRequiredBefore;
1450 }
1451 if (CurrentState.Indent == State.FirstIndent && PreviousNonComment &&
1452 !PreviousNonComment->isOneOf(tok::r_brace, TT_CtorInitializerComma)) {
1453 // Ensure that we fall back to the continuation indent width instead of
1454 // just flushing continuations left.
1455 return CurrentState.Indent + Style.ContinuationIndentWidth;
1456 }
1457 return CurrentState.Indent;
1458 }
1459
hasNestedBlockInlined(const FormatToken * Previous,const FormatToken & Current,const FormatStyle & Style)1460 static bool hasNestedBlockInlined(const FormatToken *Previous,
1461 const FormatToken &Current,
1462 const FormatStyle &Style) {
1463 if (Previous->isNot(tok::l_paren))
1464 return true;
1465 if (Previous->ParameterCount > 1)
1466 return true;
1467
1468 // Also a nested block if contains a lambda inside function with 1 parameter.
1469 return Style.BraceWrapping.BeforeLambdaBody && Current.is(TT_LambdaLSquare);
1470 }
1471
moveStateToNextToken(LineState & State,bool DryRun,bool Newline)1472 unsigned ContinuationIndenter::moveStateToNextToken(LineState &State,
1473 bool DryRun, bool Newline) {
1474 assert(State.Stack.size());
1475 const FormatToken &Current = *State.NextToken;
1476 auto &CurrentState = State.Stack.back();
1477
1478 if (Current.is(TT_CSharpGenericTypeConstraint))
1479 CurrentState.IsCSharpGenericTypeConstraint = true;
1480 if (Current.isOneOf(tok::comma, TT_BinaryOperator))
1481 CurrentState.NoLineBreakInOperand = false;
1482 if (Current.isOneOf(TT_InheritanceColon, TT_CSharpGenericTypeConstraintColon))
1483 CurrentState.AvoidBinPacking = true;
1484 if (Current.is(tok::lessless) && Current.isNot(TT_OverloadedOperator)) {
1485 if (CurrentState.FirstLessLess == 0)
1486 CurrentState.FirstLessLess = State.Column;
1487 else
1488 CurrentState.LastOperatorWrapped = Newline;
1489 }
1490 if (Current.is(TT_BinaryOperator) && Current.isNot(tok::lessless))
1491 CurrentState.LastOperatorWrapped = Newline;
1492 if (Current.is(TT_ConditionalExpr) && Current.Previous &&
1493 Current.Previous->isNot(TT_ConditionalExpr)) {
1494 CurrentState.LastOperatorWrapped = Newline;
1495 }
1496 if (Current.is(TT_ArraySubscriptLSquare) &&
1497 CurrentState.StartOfArraySubscripts == 0) {
1498 CurrentState.StartOfArraySubscripts = State.Column;
1499 }
1500
1501 auto IsWrappedConditional = [](const FormatToken &Tok) {
1502 if (!(Tok.is(TT_ConditionalExpr) && Tok.is(tok::question)))
1503 return false;
1504 if (Tok.MustBreakBefore)
1505 return true;
1506
1507 const FormatToken *Next = Tok.getNextNonComment();
1508 return Next && Next->MustBreakBefore;
1509 };
1510 if (IsWrappedConditional(Current))
1511 CurrentState.IsWrappedConditional = true;
1512 if (Style.BreakBeforeTernaryOperators && Current.is(tok::question))
1513 CurrentState.QuestionColumn = State.Column;
1514 if (!Style.BreakBeforeTernaryOperators && Current.isNot(tok::colon)) {
1515 const FormatToken *Previous = Current.Previous;
1516 while (Previous && Previous->isTrailingComment())
1517 Previous = Previous->Previous;
1518 if (Previous && Previous->is(tok::question))
1519 CurrentState.QuestionColumn = State.Column;
1520 }
1521 if (!Current.opensScope() && !Current.closesScope() &&
1522 Current.isNot(TT_PointerOrReference)) {
1523 State.LowestLevelOnLine =
1524 std::min(State.LowestLevelOnLine, Current.NestingLevel);
1525 }
1526 if (Current.isMemberAccess())
1527 CurrentState.StartOfFunctionCall = !Current.NextOperator ? 0 : State.Column;
1528 if (Current.is(TT_SelectorName))
1529 CurrentState.ObjCSelectorNameFound = true;
1530 if (Current.is(TT_CtorInitializerColon) &&
1531 Style.BreakConstructorInitializers != FormatStyle::BCIS_AfterColon) {
1532 // Indent 2 from the column, so:
1533 // SomeClass::SomeClass()
1534 // : First(...), ...
1535 // Next(...)
1536 // ^ line up here.
1537 CurrentState.Indent = State.Column + (Style.BreakConstructorInitializers ==
1538 FormatStyle::BCIS_BeforeComma
1539 ? 0
1540 : 2);
1541 CurrentState.NestedBlockIndent = CurrentState.Indent;
1542 if (Style.PackConstructorInitializers > FormatStyle::PCIS_BinPack) {
1543 CurrentState.AvoidBinPacking = true;
1544 CurrentState.BreakBeforeParameter =
1545 Style.ColumnLimit > 0 &&
1546 Style.PackConstructorInitializers != FormatStyle::PCIS_NextLine &&
1547 Style.PackConstructorInitializers != FormatStyle::PCIS_NextLineOnly;
1548 } else {
1549 CurrentState.BreakBeforeParameter = false;
1550 }
1551 }
1552 if (Current.is(TT_CtorInitializerColon) &&
1553 Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon) {
1554 CurrentState.Indent =
1555 State.FirstIndent + Style.ConstructorInitializerIndentWidth;
1556 CurrentState.NestedBlockIndent = CurrentState.Indent;
1557 if (Style.PackConstructorInitializers > FormatStyle::PCIS_BinPack)
1558 CurrentState.AvoidBinPacking = true;
1559 else
1560 CurrentState.BreakBeforeParameter = false;
1561 }
1562 if (Current.is(TT_InheritanceColon)) {
1563 CurrentState.Indent =
1564 State.FirstIndent + Style.ConstructorInitializerIndentWidth;
1565 }
1566 if (Current.isOneOf(TT_BinaryOperator, TT_ConditionalExpr) && Newline)
1567 CurrentState.NestedBlockIndent = State.Column + Current.ColumnWidth + 1;
1568 if (Current.isOneOf(TT_LambdaLSquare, TT_TrailingReturnArrow))
1569 CurrentState.LastSpace = State.Column;
1570 if (Current.is(TT_RequiresExpression) &&
1571 Style.RequiresExpressionIndentation == FormatStyle::REI_Keyword) {
1572 CurrentState.NestedBlockIndent = State.Column;
1573 }
1574
1575 // Insert scopes created by fake parenthesis.
1576 const FormatToken *Previous = Current.getPreviousNonComment();
1577
1578 // Add special behavior to support a format commonly used for JavaScript
1579 // closures:
1580 // SomeFunction(function() {
1581 // foo();
1582 // bar();
1583 // }, a, b, c);
1584 if (Current.isNot(tok::comment) && !Current.ClosesRequiresClause &&
1585 Previous && Previous->isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) &&
1586 Previous->isNot(TT_DictLiteral) && State.Stack.size() > 1 &&
1587 !CurrentState.HasMultipleNestedBlocks) {
1588 if (State.Stack[State.Stack.size() - 2].NestedBlockInlined && Newline)
1589 for (ParenState &PState : llvm::drop_end(State.Stack))
1590 PState.NoLineBreak = true;
1591 State.Stack[State.Stack.size() - 2].NestedBlockInlined = false;
1592 }
1593 if (Previous && (Previous->isOneOf(TT_BinaryOperator, TT_ConditionalExpr) ||
1594 (Previous->isOneOf(tok::l_paren, tok::comma, tok::colon) &&
1595 !Previous->isOneOf(TT_DictLiteral, TT_ObjCMethodExpr)))) {
1596 CurrentState.NestedBlockInlined =
1597 !Newline && hasNestedBlockInlined(Previous, Current, Style);
1598 }
1599
1600 moveStatePastFakeLParens(State, Newline);
1601 moveStatePastScopeCloser(State);
1602 // Do not use CurrentState here, since the two functions before may change the
1603 // Stack.
1604 bool AllowBreak = !State.Stack.back().NoLineBreak &&
1605 !State.Stack.back().NoLineBreakInOperand;
1606 moveStatePastScopeOpener(State, Newline);
1607 moveStatePastFakeRParens(State);
1608
1609 if (Current.is(TT_ObjCStringLiteral) && State.StartOfStringLiteral == 0)
1610 State.StartOfStringLiteral = State.Column + 1;
1611 if (Current.is(TT_CSharpStringLiteral) && State.StartOfStringLiteral == 0) {
1612 State.StartOfStringLiteral = State.Column + 1;
1613 } else if (Current.is(TT_TableGenMultiLineString) &&
1614 State.StartOfStringLiteral == 0) {
1615 State.StartOfStringLiteral = State.Column + 1;
1616 } else if (Current.isStringLiteral() && State.StartOfStringLiteral == 0) {
1617 State.StartOfStringLiteral = State.Column;
1618 } else if (!Current.isOneOf(tok::comment, tok::identifier, tok::hash) &&
1619 !Current.isStringLiteral()) {
1620 State.StartOfStringLiteral = 0;
1621 }
1622
1623 State.Column += Current.ColumnWidth;
1624 State.NextToken = State.NextToken->Next;
1625 // Verilog case labels are on the same unwrapped lines as the statements that
1626 // follow. TokenAnnotator identifies them and sets MustBreakBefore.
1627 // Indentation is taken care of here. A case label can only have 1 statement
1628 // in Verilog, so we don't have to worry about lines that follow.
1629 if (Style.isVerilog() && State.NextToken &&
1630 State.NextToken->MustBreakBefore &&
1631 Keywords.isVerilogEndOfLabel(Current)) {
1632 State.FirstIndent += Style.IndentWidth;
1633 CurrentState.Indent = State.FirstIndent;
1634 }
1635
1636 unsigned Penalty =
1637 handleEndOfLine(Current, State, DryRun, AllowBreak, Newline);
1638
1639 if (Current.Role)
1640 Current.Role->formatFromToken(State, this, DryRun);
1641 // If the previous has a special role, let it consume tokens as appropriate.
1642 // It is necessary to start at the previous token for the only implemented
1643 // role (comma separated list). That way, the decision whether or not to break
1644 // after the "{" is already done and both options are tried and evaluated.
1645 // FIXME: This is ugly, find a better way.
1646 if (Previous && Previous->Role)
1647 Penalty += Previous->Role->formatAfterToken(State, this, DryRun);
1648
1649 return Penalty;
1650 }
1651
moveStatePastFakeLParens(LineState & State,bool Newline)1652 void ContinuationIndenter::moveStatePastFakeLParens(LineState &State,
1653 bool Newline) {
1654 const FormatToken &Current = *State.NextToken;
1655 if (Current.FakeLParens.empty())
1656 return;
1657
1658 const FormatToken *Previous = Current.getPreviousNonComment();
1659
1660 // Don't add extra indentation for the first fake parenthesis after
1661 // 'return', assignments, opening <({[, or requires clauses. The indentation
1662 // for these cases is special cased.
1663 bool SkipFirstExtraIndent =
1664 Previous &&
1665 (Previous->opensScope() ||
1666 Previous->isOneOf(tok::semi, tok::kw_return, TT_RequiresClause) ||
1667 (Previous->getPrecedence() == prec::Assignment &&
1668 Style.AlignOperands != FormatStyle::OAS_DontAlign) ||
1669 Previous->is(TT_ObjCMethodExpr));
1670 for (const auto &PrecedenceLevel : llvm::reverse(Current.FakeLParens)) {
1671 const auto &CurrentState = State.Stack.back();
1672 ParenState NewParenState = CurrentState;
1673 NewParenState.Tok = nullptr;
1674 NewParenState.ContainsLineBreak = false;
1675 NewParenState.LastOperatorWrapped = true;
1676 NewParenState.IsChainedConditional = false;
1677 NewParenState.IsWrappedConditional = false;
1678 NewParenState.UnindentOperator = false;
1679 NewParenState.NoLineBreak =
1680 NewParenState.NoLineBreak || CurrentState.NoLineBreakInOperand;
1681
1682 // Don't propagate AvoidBinPacking into subexpressions of arg/param lists.
1683 if (PrecedenceLevel > prec::Comma)
1684 NewParenState.AvoidBinPacking = false;
1685
1686 // Indent from 'LastSpace' unless these are fake parentheses encapsulating
1687 // a builder type call after 'return' or, if the alignment after opening
1688 // brackets is disabled.
1689 if (!Current.isTrailingComment() &&
1690 (Style.AlignOperands != FormatStyle::OAS_DontAlign ||
1691 PrecedenceLevel < prec::Assignment) &&
1692 (!Previous || Previous->isNot(tok::kw_return) ||
1693 (Style.Language != FormatStyle::LK_Java && PrecedenceLevel > 0)) &&
1694 (Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign ||
1695 PrecedenceLevel != prec::Comma || Current.NestingLevel == 0)) {
1696 NewParenState.Indent = std::max(
1697 std::max(State.Column, NewParenState.Indent), CurrentState.LastSpace);
1698 }
1699
1700 // Special case for generic selection expressions, its comma-separated
1701 // expressions are not aligned to the opening paren like regular calls, but
1702 // rather continuation-indented relative to the _Generic keyword.
1703 if (Previous && Previous->endsSequence(tok::l_paren, tok::kw__Generic))
1704 NewParenState.Indent = CurrentState.LastSpace;
1705
1706 if ((shouldUnindentNextOperator(Current) ||
1707 (Previous &&
1708 (PrecedenceLevel == prec::Conditional &&
1709 Previous->is(tok::question) && Previous->is(TT_ConditionalExpr)))) &&
1710 !Newline) {
1711 // If BreakBeforeBinaryOperators is set, un-indent a bit to account for
1712 // the operator and keep the operands aligned.
1713 if (Style.AlignOperands == FormatStyle::OAS_AlignAfterOperator)
1714 NewParenState.UnindentOperator = true;
1715 // Mark indentation as alignment if the expression is aligned.
1716 if (Style.AlignOperands != FormatStyle::OAS_DontAlign)
1717 NewParenState.IsAligned = true;
1718 }
1719
1720 // Do not indent relative to the fake parentheses inserted for "." or "->".
1721 // This is a special case to make the following to statements consistent:
1722 // OuterFunction(InnerFunctionCall( // break
1723 // ParameterToInnerFunction));
1724 // OuterFunction(SomeObject.InnerFunctionCall( // break
1725 // ParameterToInnerFunction));
1726 if (PrecedenceLevel > prec::Unknown)
1727 NewParenState.LastSpace = std::max(NewParenState.LastSpace, State.Column);
1728 if (PrecedenceLevel != prec::Conditional &&
1729 Current.isNot(TT_UnaryOperator) &&
1730 Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign) {
1731 NewParenState.StartOfFunctionCall = State.Column;
1732 }
1733
1734 // Indent conditional expressions, unless they are chained "else-if"
1735 // conditionals. Never indent expression where the 'operator' is ',', ';' or
1736 // an assignment (i.e. *I <= prec::Assignment) as those have different
1737 // indentation rules. Indent other expression, unless the indentation needs
1738 // to be skipped.
1739 if (PrecedenceLevel == prec::Conditional && Previous &&
1740 Previous->is(tok::colon) && Previous->is(TT_ConditionalExpr) &&
1741 &PrecedenceLevel == &Current.FakeLParens.back() &&
1742 !CurrentState.IsWrappedConditional) {
1743 NewParenState.IsChainedConditional = true;
1744 NewParenState.UnindentOperator = State.Stack.back().UnindentOperator;
1745 } else if (PrecedenceLevel == prec::Conditional ||
1746 (!SkipFirstExtraIndent && PrecedenceLevel > prec::Assignment &&
1747 !Current.isTrailingComment())) {
1748 NewParenState.Indent += Style.ContinuationIndentWidth;
1749 }
1750 if ((Previous && !Previous->opensScope()) || PrecedenceLevel != prec::Comma)
1751 NewParenState.BreakBeforeParameter = false;
1752 State.Stack.push_back(NewParenState);
1753 SkipFirstExtraIndent = false;
1754 }
1755 }
1756
moveStatePastFakeRParens(LineState & State)1757 void ContinuationIndenter::moveStatePastFakeRParens(LineState &State) {
1758 for (unsigned i = 0, e = State.NextToken->FakeRParens; i != e; ++i) {
1759 unsigned VariablePos = State.Stack.back().VariablePos;
1760 if (State.Stack.size() == 1) {
1761 // Do not pop the last element.
1762 break;
1763 }
1764 State.Stack.pop_back();
1765 State.Stack.back().VariablePos = VariablePos;
1766 }
1767
1768 if (State.NextToken->ClosesRequiresClause && Style.IndentRequiresClause) {
1769 // Remove the indentation of the requires clauses (which is not in Indent,
1770 // but in LastSpace).
1771 State.Stack.back().LastSpace -= Style.IndentWidth;
1772 }
1773 }
1774
moveStatePastScopeOpener(LineState & State,bool Newline)1775 void ContinuationIndenter::moveStatePastScopeOpener(LineState &State,
1776 bool Newline) {
1777 const FormatToken &Current = *State.NextToken;
1778 if (!Current.opensScope())
1779 return;
1780
1781 const auto &CurrentState = State.Stack.back();
1782
1783 // Don't allow '<' or '(' in C# generic type constraints to start new scopes.
1784 if (Current.isOneOf(tok::less, tok::l_paren) &&
1785 CurrentState.IsCSharpGenericTypeConstraint) {
1786 return;
1787 }
1788
1789 if (Current.MatchingParen && Current.is(BK_Block)) {
1790 moveStateToNewBlock(State);
1791 return;
1792 }
1793
1794 unsigned NewIndent;
1795 unsigned LastSpace = CurrentState.LastSpace;
1796 bool AvoidBinPacking;
1797 bool BreakBeforeParameter = false;
1798 unsigned NestedBlockIndent = std::max(CurrentState.StartOfFunctionCall,
1799 CurrentState.NestedBlockIndent);
1800 if (Current.isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) ||
1801 opensProtoMessageField(Current, Style)) {
1802 if (Current.opensBlockOrBlockTypeList(Style)) {
1803 NewIndent = Style.IndentWidth +
1804 std::min(State.Column, CurrentState.NestedBlockIndent);
1805 } else if (Current.is(tok::l_brace)) {
1806 NewIndent =
1807 CurrentState.LastSpace + Style.BracedInitializerIndentWidth.value_or(
1808 Style.ContinuationIndentWidth);
1809 } else {
1810 NewIndent = CurrentState.LastSpace + Style.ContinuationIndentWidth;
1811 }
1812 const FormatToken *NextNonComment = Current.getNextNonComment();
1813 bool EndsInComma = Current.MatchingParen &&
1814 Current.MatchingParen->Previous &&
1815 Current.MatchingParen->Previous->is(tok::comma);
1816 AvoidBinPacking = EndsInComma || Current.is(TT_DictLiteral) ||
1817 Style.isProto() || !Style.BinPackArguments ||
1818 (NextNonComment && NextNonComment->isOneOf(
1819 TT_DesignatedInitializerPeriod,
1820 TT_DesignatedInitializerLSquare));
1821 BreakBeforeParameter = EndsInComma;
1822 if (Current.ParameterCount > 1)
1823 NestedBlockIndent = std::max(NestedBlockIndent, State.Column + 1);
1824 } else {
1825 NewIndent =
1826 Style.ContinuationIndentWidth +
1827 std::max(CurrentState.LastSpace, CurrentState.StartOfFunctionCall);
1828
1829 // Ensure that different different brackets force relative alignment, e.g.:
1830 // void SomeFunction(vector< // break
1831 // int> v);
1832 // FIXME: We likely want to do this for more combinations of brackets.
1833 if (Current.is(tok::less) && Current.ParentBracket == tok::l_paren) {
1834 NewIndent = std::max(NewIndent, CurrentState.Indent);
1835 LastSpace = std::max(LastSpace, CurrentState.Indent);
1836 }
1837
1838 bool EndsInComma =
1839 Current.MatchingParen &&
1840 Current.MatchingParen->getPreviousNonComment() &&
1841 Current.MatchingParen->getPreviousNonComment()->is(tok::comma);
1842
1843 // If ObjCBinPackProtocolList is unspecified, fall back to BinPackParameters
1844 // for backwards compatibility.
1845 bool ObjCBinPackProtocolList =
1846 (Style.ObjCBinPackProtocolList == FormatStyle::BPS_Auto &&
1847 Style.BinPackParameters) ||
1848 Style.ObjCBinPackProtocolList == FormatStyle::BPS_Always;
1849
1850 bool BinPackDeclaration =
1851 (State.Line->Type != LT_ObjCDecl && Style.BinPackParameters) ||
1852 (State.Line->Type == LT_ObjCDecl && ObjCBinPackProtocolList);
1853
1854 bool GenericSelection =
1855 Current.getPreviousNonComment() &&
1856 Current.getPreviousNonComment()->is(tok::kw__Generic);
1857
1858 AvoidBinPacking =
1859 (CurrentState.IsCSharpGenericTypeConstraint) || GenericSelection ||
1860 (Style.isJavaScript() && EndsInComma) ||
1861 (State.Line->MustBeDeclaration && !BinPackDeclaration) ||
1862 (!State.Line->MustBeDeclaration && !Style.BinPackArguments) ||
1863 (Style.ExperimentalAutoDetectBinPacking &&
1864 (Current.is(PPK_OnePerLine) ||
1865 (!BinPackInconclusiveFunctions && Current.is(PPK_Inconclusive))));
1866
1867 if (Current.is(TT_ObjCMethodExpr) && Current.MatchingParen &&
1868 Style.ObjCBreakBeforeNestedBlockParam) {
1869 if (Style.ColumnLimit) {
1870 // If this '[' opens an ObjC call, determine whether all parameters fit
1871 // into one line and put one per line if they don't.
1872 if (getLengthToMatchingParen(Current, State.Stack) + State.Column >
1873 getColumnLimit(State)) {
1874 BreakBeforeParameter = true;
1875 }
1876 } else {
1877 // For ColumnLimit = 0, we have to figure out whether there is or has to
1878 // be a line break within this call.
1879 for (const FormatToken *Tok = &Current;
1880 Tok && Tok != Current.MatchingParen; Tok = Tok->Next) {
1881 if (Tok->MustBreakBefore ||
1882 (Tok->CanBreakBefore && Tok->NewlinesBefore > 0)) {
1883 BreakBeforeParameter = true;
1884 break;
1885 }
1886 }
1887 }
1888 }
1889
1890 if (Style.isJavaScript() && EndsInComma)
1891 BreakBeforeParameter = true;
1892 }
1893 // Generally inherit NoLineBreak from the current scope to nested scope.
1894 // However, don't do this for non-empty nested blocks, dict literals and
1895 // array literals as these follow different indentation rules.
1896 bool NoLineBreak =
1897 Current.Children.empty() &&
1898 !Current.isOneOf(TT_DictLiteral, TT_ArrayInitializerLSquare) &&
1899 (CurrentState.NoLineBreak || CurrentState.NoLineBreakInOperand ||
1900 (Current.is(TT_TemplateOpener) &&
1901 CurrentState.ContainsUnwrappedBuilder));
1902 State.Stack.push_back(
1903 ParenState(&Current, NewIndent, LastSpace, AvoidBinPacking, NoLineBreak));
1904 auto &NewState = State.Stack.back();
1905 NewState.NestedBlockIndent = NestedBlockIndent;
1906 NewState.BreakBeforeParameter = BreakBeforeParameter;
1907 NewState.HasMultipleNestedBlocks = (Current.BlockParameterCount > 1);
1908
1909 if (Style.BraceWrapping.BeforeLambdaBody && Current.Next &&
1910 Current.is(tok::l_paren)) {
1911 // Search for any parameter that is a lambda.
1912 FormatToken const *next = Current.Next;
1913 while (next) {
1914 if (next->is(TT_LambdaLSquare)) {
1915 NewState.HasMultipleNestedBlocks = true;
1916 break;
1917 }
1918 next = next->Next;
1919 }
1920 }
1921
1922 NewState.IsInsideObjCArrayLiteral = Current.is(TT_ArrayInitializerLSquare) &&
1923 Current.Previous &&
1924 Current.Previous->is(tok::at);
1925 }
1926
moveStatePastScopeCloser(LineState & State)1927 void ContinuationIndenter::moveStatePastScopeCloser(LineState &State) {
1928 const FormatToken &Current = *State.NextToken;
1929 if (!Current.closesScope())
1930 return;
1931
1932 // If we encounter a closing ), ], } or >, we can remove a level from our
1933 // stacks.
1934 if (State.Stack.size() > 1 &&
1935 (Current.isOneOf(tok::r_paren, tok::r_square, TT_TemplateString) ||
1936 (Current.is(tok::r_brace) && State.NextToken != State.Line->First) ||
1937 State.NextToken->is(TT_TemplateCloser) ||
1938 (Current.is(tok::greater) && Current.is(TT_DictLiteral)))) {
1939 State.Stack.pop_back();
1940 }
1941
1942 auto &CurrentState = State.Stack.back();
1943
1944 // Reevaluate whether ObjC message arguments fit into one line.
1945 // If a receiver spans multiple lines, e.g.:
1946 // [[object block:^{
1947 // return 42;
1948 // }] a:42 b:42];
1949 // BreakBeforeParameter is calculated based on an incorrect assumption
1950 // (it is checked whether the whole expression fits into one line without
1951 // considering a line break inside a message receiver).
1952 // We check whether arguments fit after receiver scope closer (into the same
1953 // line).
1954 if (CurrentState.BreakBeforeParameter && Current.MatchingParen &&
1955 Current.MatchingParen->Previous) {
1956 const FormatToken &CurrentScopeOpener = *Current.MatchingParen->Previous;
1957 if (CurrentScopeOpener.is(TT_ObjCMethodExpr) &&
1958 CurrentScopeOpener.MatchingParen) {
1959 int NecessarySpaceInLine =
1960 getLengthToMatchingParen(CurrentScopeOpener, State.Stack) +
1961 CurrentScopeOpener.TotalLength - Current.TotalLength - 1;
1962 if (State.Column + Current.ColumnWidth + NecessarySpaceInLine <=
1963 Style.ColumnLimit) {
1964 CurrentState.BreakBeforeParameter = false;
1965 }
1966 }
1967 }
1968
1969 if (Current.is(tok::r_square)) {
1970 // If this ends the array subscript expr, reset the corresponding value.
1971 const FormatToken *NextNonComment = Current.getNextNonComment();
1972 if (NextNonComment && NextNonComment->isNot(tok::l_square))
1973 CurrentState.StartOfArraySubscripts = 0;
1974 }
1975 }
1976
moveStateToNewBlock(LineState & State)1977 void ContinuationIndenter::moveStateToNewBlock(LineState &State) {
1978 if (Style.LambdaBodyIndentation == FormatStyle::LBI_OuterScope &&
1979 State.NextToken->is(TT_LambdaLBrace) &&
1980 !State.Line->MightBeFunctionDecl) {
1981 State.Stack.back().NestedBlockIndent = State.FirstIndent;
1982 }
1983 unsigned NestedBlockIndent = State.Stack.back().NestedBlockIndent;
1984 // ObjC block sometimes follow special indentation rules.
1985 unsigned NewIndent =
1986 NestedBlockIndent + (State.NextToken->is(TT_ObjCBlockLBrace)
1987 ? Style.ObjCBlockIndentWidth
1988 : Style.IndentWidth);
1989 State.Stack.push_back(ParenState(State.NextToken, NewIndent,
1990 State.Stack.back().LastSpace,
1991 /*AvoidBinPacking=*/true,
1992 /*NoLineBreak=*/false));
1993 State.Stack.back().NestedBlockIndent = NestedBlockIndent;
1994 State.Stack.back().BreakBeforeParameter = true;
1995 }
1996
getLastLineEndColumn(StringRef Text,unsigned StartColumn,unsigned TabWidth,encoding::Encoding Encoding)1997 static unsigned getLastLineEndColumn(StringRef Text, unsigned StartColumn,
1998 unsigned TabWidth,
1999 encoding::Encoding Encoding) {
2000 size_t LastNewlinePos = Text.find_last_of("\n");
2001 if (LastNewlinePos == StringRef::npos) {
2002 return StartColumn +
2003 encoding::columnWidthWithTabs(Text, StartColumn, TabWidth, Encoding);
2004 } else {
2005 return encoding::columnWidthWithTabs(Text.substr(LastNewlinePos),
2006 /*StartColumn=*/0, TabWidth, Encoding);
2007 }
2008 }
2009
reformatRawStringLiteral(const FormatToken & Current,LineState & State,const FormatStyle & RawStringStyle,bool DryRun,bool Newline)2010 unsigned ContinuationIndenter::reformatRawStringLiteral(
2011 const FormatToken &Current, LineState &State,
2012 const FormatStyle &RawStringStyle, bool DryRun, bool Newline) {
2013 unsigned StartColumn = State.Column - Current.ColumnWidth;
2014 StringRef OldDelimiter = *getRawStringDelimiter(Current.TokenText);
2015 StringRef NewDelimiter =
2016 getCanonicalRawStringDelimiter(Style, RawStringStyle.Language);
2017 if (NewDelimiter.empty())
2018 NewDelimiter = OldDelimiter;
2019 // The text of a raw string is between the leading 'R"delimiter(' and the
2020 // trailing 'delimiter)"'.
2021 unsigned OldPrefixSize = 3 + OldDelimiter.size();
2022 unsigned OldSuffixSize = 2 + OldDelimiter.size();
2023 // We create a virtual text environment which expects a null-terminated
2024 // string, so we cannot use StringRef.
2025 std::string RawText = std::string(
2026 Current.TokenText.substr(OldPrefixSize).drop_back(OldSuffixSize));
2027 if (NewDelimiter != OldDelimiter) {
2028 // Don't update to the canonical delimiter 'deli' if ')deli"' occurs in the
2029 // raw string.
2030 std::string CanonicalDelimiterSuffix = (")" + NewDelimiter + "\"").str();
2031 if (StringRef(RawText).contains(CanonicalDelimiterSuffix))
2032 NewDelimiter = OldDelimiter;
2033 }
2034
2035 unsigned NewPrefixSize = 3 + NewDelimiter.size();
2036 unsigned NewSuffixSize = 2 + NewDelimiter.size();
2037
2038 // The first start column is the column the raw text starts after formatting.
2039 unsigned FirstStartColumn = StartColumn + NewPrefixSize;
2040
2041 // The next start column is the intended indentation a line break inside
2042 // the raw string at level 0. It is determined by the following rules:
2043 // - if the content starts on newline, it is one level more than the current
2044 // indent, and
2045 // - if the content does not start on a newline, it is the first start
2046 // column.
2047 // These rules have the advantage that the formatted content both does not
2048 // violate the rectangle rule and visually flows within the surrounding
2049 // source.
2050 bool ContentStartsOnNewline = Current.TokenText[OldPrefixSize] == '\n';
2051 // If this token is the last parameter (checked by looking if it's followed by
2052 // `)` and is not on a newline, the base the indent off the line's nested
2053 // block indent. Otherwise, base the indent off the arguments indent, so we
2054 // can achieve:
2055 //
2056 // fffffffffff(1, 2, 3, R"pb(
2057 // key1: 1 #
2058 // key2: 2)pb");
2059 //
2060 // fffffffffff(1, 2, 3,
2061 // R"pb(
2062 // key1: 1 #
2063 // key2: 2
2064 // )pb");
2065 //
2066 // fffffffffff(1, 2, 3,
2067 // R"pb(
2068 // key1: 1 #
2069 // key2: 2
2070 // )pb",
2071 // 5);
2072 unsigned CurrentIndent =
2073 (!Newline && Current.Next && Current.Next->is(tok::r_paren))
2074 ? State.Stack.back().NestedBlockIndent
2075 : State.Stack.back().Indent;
2076 unsigned NextStartColumn = ContentStartsOnNewline
2077 ? CurrentIndent + Style.IndentWidth
2078 : FirstStartColumn;
2079
2080 // The last start column is the column the raw string suffix starts if it is
2081 // put on a newline.
2082 // The last start column is the intended indentation of the raw string postfix
2083 // if it is put on a newline. It is determined by the following rules:
2084 // - if the raw string prefix starts on a newline, it is the column where
2085 // that raw string prefix starts, and
2086 // - if the raw string prefix does not start on a newline, it is the current
2087 // indent.
2088 unsigned LastStartColumn =
2089 Current.NewlinesBefore ? FirstStartColumn - NewPrefixSize : CurrentIndent;
2090
2091 std::pair<tooling::Replacements, unsigned> Fixes = internal::reformat(
2092 RawStringStyle, RawText, {tooling::Range(0, RawText.size())},
2093 FirstStartColumn, NextStartColumn, LastStartColumn, "<stdin>",
2094 /*Status=*/nullptr);
2095
2096 auto NewCode = applyAllReplacements(RawText, Fixes.first);
2097 tooling::Replacements NoFixes;
2098 if (!NewCode)
2099 return addMultilineToken(Current, State);
2100 if (!DryRun) {
2101 if (NewDelimiter != OldDelimiter) {
2102 // In 'R"delimiter(...', the delimiter starts 2 characters after the start
2103 // of the token.
2104 SourceLocation PrefixDelimiterStart =
2105 Current.Tok.getLocation().getLocWithOffset(2);
2106 auto PrefixErr = Whitespaces.addReplacement(tooling::Replacement(
2107 SourceMgr, PrefixDelimiterStart, OldDelimiter.size(), NewDelimiter));
2108 if (PrefixErr) {
2109 llvm::errs()
2110 << "Failed to update the prefix delimiter of a raw string: "
2111 << llvm::toString(std::move(PrefixErr)) << "\n";
2112 }
2113 // In 'R"delimiter(...)delimiter"', the suffix delimiter starts at
2114 // position length - 1 - |delimiter|.
2115 SourceLocation SuffixDelimiterStart =
2116 Current.Tok.getLocation().getLocWithOffset(Current.TokenText.size() -
2117 1 - OldDelimiter.size());
2118 auto SuffixErr = Whitespaces.addReplacement(tooling::Replacement(
2119 SourceMgr, SuffixDelimiterStart, OldDelimiter.size(), NewDelimiter));
2120 if (SuffixErr) {
2121 llvm::errs()
2122 << "Failed to update the suffix delimiter of a raw string: "
2123 << llvm::toString(std::move(SuffixErr)) << "\n";
2124 }
2125 }
2126 SourceLocation OriginLoc =
2127 Current.Tok.getLocation().getLocWithOffset(OldPrefixSize);
2128 for (const tooling::Replacement &Fix : Fixes.first) {
2129 auto Err = Whitespaces.addReplacement(tooling::Replacement(
2130 SourceMgr, OriginLoc.getLocWithOffset(Fix.getOffset()),
2131 Fix.getLength(), Fix.getReplacementText()));
2132 if (Err) {
2133 llvm::errs() << "Failed to reformat raw string: "
2134 << llvm::toString(std::move(Err)) << "\n";
2135 }
2136 }
2137 }
2138 unsigned RawLastLineEndColumn = getLastLineEndColumn(
2139 *NewCode, FirstStartColumn, Style.TabWidth, Encoding);
2140 State.Column = RawLastLineEndColumn + NewSuffixSize;
2141 // Since we're updating the column to after the raw string literal here, we
2142 // have to manually add the penalty for the prefix R"delim( over the column
2143 // limit.
2144 unsigned PrefixExcessCharacters =
2145 StartColumn + NewPrefixSize > Style.ColumnLimit
2146 ? StartColumn + NewPrefixSize - Style.ColumnLimit
2147 : 0;
2148 bool IsMultiline =
2149 ContentStartsOnNewline || (NewCode->find('\n') != std::string::npos);
2150 if (IsMultiline) {
2151 // Break before further function parameters on all levels.
2152 for (ParenState &Paren : State.Stack)
2153 Paren.BreakBeforeParameter = true;
2154 }
2155 return Fixes.second + PrefixExcessCharacters * Style.PenaltyExcessCharacter;
2156 }
2157
addMultilineToken(const FormatToken & Current,LineState & State)2158 unsigned ContinuationIndenter::addMultilineToken(const FormatToken &Current,
2159 LineState &State) {
2160 // Break before further function parameters on all levels.
2161 for (ParenState &Paren : State.Stack)
2162 Paren.BreakBeforeParameter = true;
2163
2164 unsigned ColumnsUsed = State.Column;
2165 // We can only affect layout of the first and the last line, so the penalty
2166 // for all other lines is constant, and we ignore it.
2167 State.Column = Current.LastLineColumnWidth;
2168
2169 if (ColumnsUsed > getColumnLimit(State))
2170 return Style.PenaltyExcessCharacter * (ColumnsUsed - getColumnLimit(State));
2171 return 0;
2172 }
2173
handleEndOfLine(const FormatToken & Current,LineState & State,bool DryRun,bool AllowBreak,bool Newline)2174 unsigned ContinuationIndenter::handleEndOfLine(const FormatToken &Current,
2175 LineState &State, bool DryRun,
2176 bool AllowBreak, bool Newline) {
2177 unsigned Penalty = 0;
2178 // Compute the raw string style to use in case this is a raw string literal
2179 // that can be reformatted.
2180 auto RawStringStyle = getRawStringStyle(Current, State);
2181 if (RawStringStyle && !Current.Finalized) {
2182 Penalty = reformatRawStringLiteral(Current, State, *RawStringStyle, DryRun,
2183 Newline);
2184 } else if (Current.IsMultiline && Current.isNot(TT_BlockComment)) {
2185 // Don't break multi-line tokens other than block comments and raw string
2186 // literals. Instead, just update the state.
2187 Penalty = addMultilineToken(Current, State);
2188 } else if (State.Line->Type != LT_ImportStatement) {
2189 // We generally don't break import statements.
2190 LineState OriginalState = State;
2191
2192 // Whether we force the reflowing algorithm to stay strictly within the
2193 // column limit.
2194 bool Strict = false;
2195 // Whether the first non-strict attempt at reflowing did intentionally
2196 // exceed the column limit.
2197 bool Exceeded = false;
2198 std::tie(Penalty, Exceeded) = breakProtrudingToken(
2199 Current, State, AllowBreak, /*DryRun=*/true, Strict);
2200 if (Exceeded) {
2201 // If non-strict reflowing exceeds the column limit, try whether strict
2202 // reflowing leads to an overall lower penalty.
2203 LineState StrictState = OriginalState;
2204 unsigned StrictPenalty =
2205 breakProtrudingToken(Current, StrictState, AllowBreak,
2206 /*DryRun=*/true, /*Strict=*/true)
2207 .first;
2208 Strict = StrictPenalty <= Penalty;
2209 if (Strict) {
2210 Penalty = StrictPenalty;
2211 State = StrictState;
2212 }
2213 }
2214 if (!DryRun) {
2215 // If we're not in dry-run mode, apply the changes with the decision on
2216 // strictness made above.
2217 breakProtrudingToken(Current, OriginalState, AllowBreak, /*DryRun=*/false,
2218 Strict);
2219 }
2220 }
2221 if (State.Column > getColumnLimit(State)) {
2222 unsigned ExcessCharacters = State.Column - getColumnLimit(State);
2223 Penalty += Style.PenaltyExcessCharacter * ExcessCharacters;
2224 }
2225 return Penalty;
2226 }
2227
2228 // Returns the enclosing function name of a token, or the empty string if not
2229 // found.
getEnclosingFunctionName(const FormatToken & Current)2230 static StringRef getEnclosingFunctionName(const FormatToken &Current) {
2231 // Look for: 'function(' or 'function<templates>(' before Current.
2232 auto Tok = Current.getPreviousNonComment();
2233 if (!Tok || Tok->isNot(tok::l_paren))
2234 return "";
2235 Tok = Tok->getPreviousNonComment();
2236 if (!Tok)
2237 return "";
2238 if (Tok->is(TT_TemplateCloser)) {
2239 Tok = Tok->MatchingParen;
2240 if (Tok)
2241 Tok = Tok->getPreviousNonComment();
2242 }
2243 if (!Tok || Tok->isNot(tok::identifier))
2244 return "";
2245 return Tok->TokenText;
2246 }
2247
2248 std::optional<FormatStyle>
getRawStringStyle(const FormatToken & Current,const LineState & State)2249 ContinuationIndenter::getRawStringStyle(const FormatToken &Current,
2250 const LineState &State) {
2251 if (!Current.isStringLiteral())
2252 return std::nullopt;
2253 auto Delimiter = getRawStringDelimiter(Current.TokenText);
2254 if (!Delimiter)
2255 return std::nullopt;
2256 auto RawStringStyle = RawStringFormats.getDelimiterStyle(*Delimiter);
2257 if (!RawStringStyle && Delimiter->empty()) {
2258 RawStringStyle = RawStringFormats.getEnclosingFunctionStyle(
2259 getEnclosingFunctionName(Current));
2260 }
2261 if (!RawStringStyle)
2262 return std::nullopt;
2263 RawStringStyle->ColumnLimit = getColumnLimit(State);
2264 return RawStringStyle;
2265 }
2266
2267 std::unique_ptr<BreakableToken>
createBreakableToken(const FormatToken & Current,LineState & State,bool AllowBreak)2268 ContinuationIndenter::createBreakableToken(const FormatToken &Current,
2269 LineState &State, bool AllowBreak) {
2270 unsigned StartColumn = State.Column - Current.ColumnWidth;
2271 if (Current.isStringLiteral()) {
2272 // Strings in JSON cannot be broken. Breaking strings in JavaScript is
2273 // disabled for now.
2274 if (Style.isJson() || Style.isJavaScript() || !Style.BreakStringLiterals ||
2275 !AllowBreak) {
2276 return nullptr;
2277 }
2278
2279 // Don't break string literals inside preprocessor directives (except for
2280 // #define directives, as their contents are stored in separate lines and
2281 // are not affected by this check).
2282 // This way we avoid breaking code with line directives and unknown
2283 // preprocessor directives that contain long string literals.
2284 if (State.Line->Type == LT_PreprocessorDirective)
2285 return nullptr;
2286 // Exempts unterminated string literals from line breaking. The user will
2287 // likely want to terminate the string before any line breaking is done.
2288 if (Current.IsUnterminatedLiteral)
2289 return nullptr;
2290 // Don't break string literals inside Objective-C array literals (doing so
2291 // raises the warning -Wobjc-string-concatenation).
2292 if (State.Stack.back().IsInsideObjCArrayLiteral)
2293 return nullptr;
2294
2295 // The "DPI"/"DPI-C" in SystemVerilog direct programming interface
2296 // imports/exports cannot be split, e.g.
2297 // `import "DPI" function foo();`
2298 // FIXME: make this use same infra as C++ import checks
2299 if (Style.isVerilog() && Current.Previous &&
2300 Current.Previous->isOneOf(tok::kw_export, Keywords.kw_import)) {
2301 return nullptr;
2302 }
2303 StringRef Text = Current.TokenText;
2304
2305 // We need this to address the case where there is an unbreakable tail only
2306 // if certain other formatting decisions have been taken. The
2307 // UnbreakableTailLength of Current is an overapproximation in that case and
2308 // we need to be correct here.
2309 unsigned UnbreakableTailLength = (State.NextToken && canBreak(State))
2310 ? 0
2311 : Current.UnbreakableTailLength;
2312
2313 if (Style.isVerilog() || Style.Language == FormatStyle::LK_Java ||
2314 Style.isJavaScript() || Style.isCSharp()) {
2315 BreakableStringLiteralUsingOperators::QuoteStyleType QuoteStyle;
2316 if (Style.isJavaScript() && Text.starts_with("'") &&
2317 Text.ends_with("'")) {
2318 QuoteStyle = BreakableStringLiteralUsingOperators::SingleQuotes;
2319 } else if (Style.isCSharp() && Text.starts_with("@\"") &&
2320 Text.ends_with("\"")) {
2321 QuoteStyle = BreakableStringLiteralUsingOperators::AtDoubleQuotes;
2322 } else if (Text.starts_with("\"") && Text.ends_with("\"")) {
2323 QuoteStyle = BreakableStringLiteralUsingOperators::DoubleQuotes;
2324 } else {
2325 return nullptr;
2326 }
2327 return std::make_unique<BreakableStringLiteralUsingOperators>(
2328 Current, QuoteStyle,
2329 /*UnindentPlus=*/shouldUnindentNextOperator(Current), StartColumn,
2330 UnbreakableTailLength, State.Line->InPPDirective, Encoding, Style);
2331 }
2332
2333 StringRef Prefix;
2334 StringRef Postfix;
2335 // FIXME: Handle whitespace between '_T', '(', '"..."', and ')'.
2336 // FIXME: Store Prefix and Suffix (or PrefixLength and SuffixLength to
2337 // reduce the overhead) for each FormatToken, which is a string, so that we
2338 // don't run multiple checks here on the hot path.
2339 if ((Text.ends_with(Postfix = "\"") &&
2340 (Text.starts_with(Prefix = "@\"") || Text.starts_with(Prefix = "\"") ||
2341 Text.starts_with(Prefix = "u\"") ||
2342 Text.starts_with(Prefix = "U\"") ||
2343 Text.starts_with(Prefix = "u8\"") ||
2344 Text.starts_with(Prefix = "L\""))) ||
2345 (Text.starts_with(Prefix = "_T(\"") &&
2346 Text.ends_with(Postfix = "\")"))) {
2347 return std::make_unique<BreakableStringLiteral>(
2348 Current, StartColumn, Prefix, Postfix, UnbreakableTailLength,
2349 State.Line->InPPDirective, Encoding, Style);
2350 }
2351 } else if (Current.is(TT_BlockComment)) {
2352 if (!Style.ReflowComments ||
2353 // If a comment token switches formatting, like
2354 // /* clang-format on */, we don't want to break it further,
2355 // but we may still want to adjust its indentation.
2356 switchesFormatting(Current)) {
2357 return nullptr;
2358 }
2359 return std::make_unique<BreakableBlockComment>(
2360 Current, StartColumn, Current.OriginalColumn, !Current.Previous,
2361 State.Line->InPPDirective, Encoding, Style, Whitespaces.useCRLF());
2362 } else if (Current.is(TT_LineComment) &&
2363 (!Current.Previous ||
2364 Current.Previous->isNot(TT_ImplicitStringLiteral))) {
2365 bool RegularComments = [&]() {
2366 for (const FormatToken *T = &Current; T && T->is(TT_LineComment);
2367 T = T->Next) {
2368 if (!(T->TokenText.starts_with("//") || T->TokenText.starts_with("#")))
2369 return false;
2370 }
2371 return true;
2372 }();
2373 if (!Style.ReflowComments ||
2374 CommentPragmasRegex.match(Current.TokenText.substr(2)) ||
2375 switchesFormatting(Current) || !RegularComments) {
2376 return nullptr;
2377 }
2378 return std::make_unique<BreakableLineCommentSection>(
2379 Current, StartColumn, /*InPPDirective=*/false, Encoding, Style);
2380 }
2381 return nullptr;
2382 }
2383
2384 std::pair<unsigned, bool>
breakProtrudingToken(const FormatToken & Current,LineState & State,bool AllowBreak,bool DryRun,bool Strict)2385 ContinuationIndenter::breakProtrudingToken(const FormatToken &Current,
2386 LineState &State, bool AllowBreak,
2387 bool DryRun, bool Strict) {
2388 std::unique_ptr<const BreakableToken> Token =
2389 createBreakableToken(Current, State, AllowBreak);
2390 if (!Token)
2391 return {0, false};
2392 assert(Token->getLineCount() > 0);
2393 unsigned ColumnLimit = getColumnLimit(State);
2394 if (Current.is(TT_LineComment)) {
2395 // We don't insert backslashes when breaking line comments.
2396 ColumnLimit = Style.ColumnLimit;
2397 }
2398 if (ColumnLimit == 0) {
2399 // To make the rest of the function easier set the column limit to the
2400 // maximum, if there should be no limit.
2401 ColumnLimit = std::numeric_limits<decltype(ColumnLimit)>::max();
2402 }
2403 if (Current.UnbreakableTailLength >= ColumnLimit)
2404 return {0, false};
2405 // ColumnWidth was already accounted into State.Column before calling
2406 // breakProtrudingToken.
2407 unsigned StartColumn = State.Column - Current.ColumnWidth;
2408 unsigned NewBreakPenalty = Current.isStringLiteral()
2409 ? Style.PenaltyBreakString
2410 : Style.PenaltyBreakComment;
2411 // Stores whether we intentionally decide to let a line exceed the column
2412 // limit.
2413 bool Exceeded = false;
2414 // Stores whether we introduce a break anywhere in the token.
2415 bool BreakInserted = Token->introducesBreakBeforeToken();
2416 // Store whether we inserted a new line break at the end of the previous
2417 // logical line.
2418 bool NewBreakBefore = false;
2419 // We use a conservative reflowing strategy. Reflow starts after a line is
2420 // broken or the corresponding whitespace compressed. Reflow ends as soon as a
2421 // line that doesn't get reflown with the previous line is reached.
2422 bool Reflow = false;
2423 // Keep track of where we are in the token:
2424 // Where we are in the content of the current logical line.
2425 unsigned TailOffset = 0;
2426 // The column number we're currently at.
2427 unsigned ContentStartColumn =
2428 Token->getContentStartColumn(0, /*Break=*/false);
2429 // The number of columns left in the current logical line after TailOffset.
2430 unsigned RemainingTokenColumns =
2431 Token->getRemainingLength(0, TailOffset, ContentStartColumn);
2432 // Adapt the start of the token, for example indent.
2433 if (!DryRun)
2434 Token->adaptStartOfLine(0, Whitespaces);
2435
2436 unsigned ContentIndent = 0;
2437 unsigned Penalty = 0;
2438 LLVM_DEBUG(llvm::dbgs() << "Breaking protruding token at column "
2439 << StartColumn << ".\n");
2440 for (unsigned LineIndex = 0, EndIndex = Token->getLineCount();
2441 LineIndex != EndIndex; ++LineIndex) {
2442 LLVM_DEBUG(llvm::dbgs()
2443 << " Line: " << LineIndex << " (Reflow: " << Reflow << ")\n");
2444 NewBreakBefore = false;
2445 // If we did reflow the previous line, we'll try reflowing again. Otherwise
2446 // we'll start reflowing if the current line is broken or whitespace is
2447 // compressed.
2448 bool TryReflow = Reflow;
2449 // Break the current token until we can fit the rest of the line.
2450 while (ContentStartColumn + RemainingTokenColumns > ColumnLimit) {
2451 LLVM_DEBUG(llvm::dbgs() << " Over limit, need: "
2452 << (ContentStartColumn + RemainingTokenColumns)
2453 << ", space: " << ColumnLimit
2454 << ", reflown prefix: " << ContentStartColumn
2455 << ", offset in line: " << TailOffset << "\n");
2456 // If the current token doesn't fit, find the latest possible split in the
2457 // current line so that breaking at it will be under the column limit.
2458 // FIXME: Use the earliest possible split while reflowing to correctly
2459 // compress whitespace within a line.
2460 BreakableToken::Split Split =
2461 Token->getSplit(LineIndex, TailOffset, ColumnLimit,
2462 ContentStartColumn, CommentPragmasRegex);
2463 if (Split.first == StringRef::npos) {
2464 // No break opportunity - update the penalty and continue with the next
2465 // logical line.
2466 if (LineIndex < EndIndex - 1) {
2467 // The last line's penalty is handled in addNextStateToQueue() or when
2468 // calling replaceWhitespaceAfterLastLine below.
2469 Penalty += Style.PenaltyExcessCharacter *
2470 (ContentStartColumn + RemainingTokenColumns - ColumnLimit);
2471 }
2472 LLVM_DEBUG(llvm::dbgs() << " No break opportunity.\n");
2473 break;
2474 }
2475 assert(Split.first != 0);
2476
2477 if (Token->supportsReflow()) {
2478 // Check whether the next natural split point after the current one can
2479 // still fit the line, either because we can compress away whitespace,
2480 // or because the penalty the excess characters introduce is lower than
2481 // the break penalty.
2482 // We only do this for tokens that support reflowing, and thus allow us
2483 // to change the whitespace arbitrarily (e.g. comments).
2484 // Other tokens, like string literals, can be broken on arbitrary
2485 // positions.
2486
2487 // First, compute the columns from TailOffset to the next possible split
2488 // position.
2489 // For example:
2490 // ColumnLimit: |
2491 // // Some text that breaks
2492 // ^ tail offset
2493 // ^-- split
2494 // ^-------- to split columns
2495 // ^--- next split
2496 // ^--------------- to next split columns
2497 unsigned ToSplitColumns = Token->getRangeLength(
2498 LineIndex, TailOffset, Split.first, ContentStartColumn);
2499 LLVM_DEBUG(llvm::dbgs() << " ToSplit: " << ToSplitColumns << "\n");
2500
2501 BreakableToken::Split NextSplit = Token->getSplit(
2502 LineIndex, TailOffset + Split.first + Split.second, ColumnLimit,
2503 ContentStartColumn + ToSplitColumns + 1, CommentPragmasRegex);
2504 // Compute the columns necessary to fit the next non-breakable sequence
2505 // into the current line.
2506 unsigned ToNextSplitColumns = 0;
2507 if (NextSplit.first == StringRef::npos) {
2508 ToNextSplitColumns = Token->getRemainingLength(LineIndex, TailOffset,
2509 ContentStartColumn);
2510 } else {
2511 ToNextSplitColumns = Token->getRangeLength(
2512 LineIndex, TailOffset,
2513 Split.first + Split.second + NextSplit.first, ContentStartColumn);
2514 }
2515 // Compress the whitespace between the break and the start of the next
2516 // unbreakable sequence.
2517 ToNextSplitColumns =
2518 Token->getLengthAfterCompression(ToNextSplitColumns, Split);
2519 LLVM_DEBUG(llvm::dbgs()
2520 << " ContentStartColumn: " << ContentStartColumn << "\n");
2521 LLVM_DEBUG(llvm::dbgs()
2522 << " ToNextSplit: " << ToNextSplitColumns << "\n");
2523 // If the whitespace compression makes us fit, continue on the current
2524 // line.
2525 bool ContinueOnLine =
2526 ContentStartColumn + ToNextSplitColumns <= ColumnLimit;
2527 unsigned ExcessCharactersPenalty = 0;
2528 if (!ContinueOnLine && !Strict) {
2529 // Similarly, if the excess characters' penalty is lower than the
2530 // penalty of introducing a new break, continue on the current line.
2531 ExcessCharactersPenalty =
2532 (ContentStartColumn + ToNextSplitColumns - ColumnLimit) *
2533 Style.PenaltyExcessCharacter;
2534 LLVM_DEBUG(llvm::dbgs()
2535 << " Penalty excess: " << ExcessCharactersPenalty
2536 << "\n break : " << NewBreakPenalty << "\n");
2537 if (ExcessCharactersPenalty < NewBreakPenalty) {
2538 Exceeded = true;
2539 ContinueOnLine = true;
2540 }
2541 }
2542 if (ContinueOnLine) {
2543 LLVM_DEBUG(llvm::dbgs() << " Continuing on line...\n");
2544 // The current line fits after compressing the whitespace - reflow
2545 // the next line into it if possible.
2546 TryReflow = true;
2547 if (!DryRun) {
2548 Token->compressWhitespace(LineIndex, TailOffset, Split,
2549 Whitespaces);
2550 }
2551 // When we continue on the same line, leave one space between content.
2552 ContentStartColumn += ToSplitColumns + 1;
2553 Penalty += ExcessCharactersPenalty;
2554 TailOffset += Split.first + Split.second;
2555 RemainingTokenColumns = Token->getRemainingLength(
2556 LineIndex, TailOffset, ContentStartColumn);
2557 continue;
2558 }
2559 }
2560 LLVM_DEBUG(llvm::dbgs() << " Breaking...\n");
2561 // Update the ContentIndent only if the current line was not reflown with
2562 // the previous line, since in that case the previous line should still
2563 // determine the ContentIndent. Also never intent the last line.
2564 if (!Reflow)
2565 ContentIndent = Token->getContentIndent(LineIndex);
2566 LLVM_DEBUG(llvm::dbgs()
2567 << " ContentIndent: " << ContentIndent << "\n");
2568 ContentStartColumn = ContentIndent + Token->getContentStartColumn(
2569 LineIndex, /*Break=*/true);
2570
2571 unsigned NewRemainingTokenColumns = Token->getRemainingLength(
2572 LineIndex, TailOffset + Split.first + Split.second,
2573 ContentStartColumn);
2574 if (NewRemainingTokenColumns == 0) {
2575 // No content to indent.
2576 ContentIndent = 0;
2577 ContentStartColumn =
2578 Token->getContentStartColumn(LineIndex, /*Break=*/true);
2579 NewRemainingTokenColumns = Token->getRemainingLength(
2580 LineIndex, TailOffset + Split.first + Split.second,
2581 ContentStartColumn);
2582 }
2583
2584 // When breaking before a tab character, it may be moved by a few columns,
2585 // but will still be expanded to the next tab stop, so we don't save any
2586 // columns.
2587 if (NewRemainingTokenColumns >= RemainingTokenColumns) {
2588 // FIXME: Do we need to adjust the penalty?
2589 break;
2590 }
2591
2592 LLVM_DEBUG(llvm::dbgs() << " Breaking at: " << TailOffset + Split.first
2593 << ", " << Split.second << "\n");
2594 if (!DryRun) {
2595 Token->insertBreak(LineIndex, TailOffset, Split, ContentIndent,
2596 Whitespaces);
2597 }
2598
2599 Penalty += NewBreakPenalty;
2600 TailOffset += Split.first + Split.second;
2601 RemainingTokenColumns = NewRemainingTokenColumns;
2602 BreakInserted = true;
2603 NewBreakBefore = true;
2604 }
2605 // In case there's another line, prepare the state for the start of the next
2606 // line.
2607 if (LineIndex + 1 != EndIndex) {
2608 unsigned NextLineIndex = LineIndex + 1;
2609 if (NewBreakBefore) {
2610 // After breaking a line, try to reflow the next line into the current
2611 // one once RemainingTokenColumns fits.
2612 TryReflow = true;
2613 }
2614 if (TryReflow) {
2615 // We decided that we want to try reflowing the next line into the
2616 // current one.
2617 // We will now adjust the state as if the reflow is successful (in
2618 // preparation for the next line), and see whether that works. If we
2619 // decide that we cannot reflow, we will later reset the state to the
2620 // start of the next line.
2621 Reflow = false;
2622 // As we did not continue breaking the line, RemainingTokenColumns is
2623 // known to fit after ContentStartColumn. Adapt ContentStartColumn to
2624 // the position at which we want to format the next line if we do
2625 // actually reflow.
2626 // When we reflow, we need to add a space between the end of the current
2627 // line and the next line's start column.
2628 ContentStartColumn += RemainingTokenColumns + 1;
2629 // Get the split that we need to reflow next logical line into the end
2630 // of the current one; the split will include any leading whitespace of
2631 // the next logical line.
2632 BreakableToken::Split SplitBeforeNext =
2633 Token->getReflowSplit(NextLineIndex, CommentPragmasRegex);
2634 LLVM_DEBUG(llvm::dbgs()
2635 << " Size of reflown text: " << ContentStartColumn
2636 << "\n Potential reflow split: ");
2637 if (SplitBeforeNext.first != StringRef::npos) {
2638 LLVM_DEBUG(llvm::dbgs() << SplitBeforeNext.first << ", "
2639 << SplitBeforeNext.second << "\n");
2640 TailOffset = SplitBeforeNext.first + SplitBeforeNext.second;
2641 // If the rest of the next line fits into the current line below the
2642 // column limit, we can safely reflow.
2643 RemainingTokenColumns = Token->getRemainingLength(
2644 NextLineIndex, TailOffset, ContentStartColumn);
2645 Reflow = true;
2646 if (ContentStartColumn + RemainingTokenColumns > ColumnLimit) {
2647 LLVM_DEBUG(llvm::dbgs()
2648 << " Over limit after reflow, need: "
2649 << (ContentStartColumn + RemainingTokenColumns)
2650 << ", space: " << ColumnLimit
2651 << ", reflown prefix: " << ContentStartColumn
2652 << ", offset in line: " << TailOffset << "\n");
2653 // If the whole next line does not fit, try to find a point in
2654 // the next line at which we can break so that attaching the part
2655 // of the next line to that break point onto the current line is
2656 // below the column limit.
2657 BreakableToken::Split Split =
2658 Token->getSplit(NextLineIndex, TailOffset, ColumnLimit,
2659 ContentStartColumn, CommentPragmasRegex);
2660 if (Split.first == StringRef::npos) {
2661 LLVM_DEBUG(llvm::dbgs() << " Did not find later break\n");
2662 Reflow = false;
2663 } else {
2664 // Check whether the first split point gets us below the column
2665 // limit. Note that we will execute this split below as part of
2666 // the normal token breaking and reflow logic within the line.
2667 unsigned ToSplitColumns = Token->getRangeLength(
2668 NextLineIndex, TailOffset, Split.first, ContentStartColumn);
2669 if (ContentStartColumn + ToSplitColumns > ColumnLimit) {
2670 LLVM_DEBUG(llvm::dbgs() << " Next split protrudes, need: "
2671 << (ContentStartColumn + ToSplitColumns)
2672 << ", space: " << ColumnLimit);
2673 unsigned ExcessCharactersPenalty =
2674 (ContentStartColumn + ToSplitColumns - ColumnLimit) *
2675 Style.PenaltyExcessCharacter;
2676 if (NewBreakPenalty < ExcessCharactersPenalty)
2677 Reflow = false;
2678 }
2679 }
2680 }
2681 } else {
2682 LLVM_DEBUG(llvm::dbgs() << "not found.\n");
2683 }
2684 }
2685 if (!Reflow) {
2686 // If we didn't reflow into the next line, the only space to consider is
2687 // the next logical line. Reset our state to match the start of the next
2688 // line.
2689 TailOffset = 0;
2690 ContentStartColumn =
2691 Token->getContentStartColumn(NextLineIndex, /*Break=*/false);
2692 RemainingTokenColumns = Token->getRemainingLength(
2693 NextLineIndex, TailOffset, ContentStartColumn);
2694 // Adapt the start of the token, for example indent.
2695 if (!DryRun)
2696 Token->adaptStartOfLine(NextLineIndex, Whitespaces);
2697 } else {
2698 // If we found a reflow split and have added a new break before the next
2699 // line, we are going to remove the line break at the start of the next
2700 // logical line. For example, here we'll add a new line break after
2701 // 'text', and subsequently delete the line break between 'that' and
2702 // 'reflows'.
2703 // // some text that
2704 // // reflows
2705 // ->
2706 // // some text
2707 // // that reflows
2708 // When adding the line break, we also added the penalty for it, so we
2709 // need to subtract that penalty again when we remove the line break due
2710 // to reflowing.
2711 if (NewBreakBefore) {
2712 assert(Penalty >= NewBreakPenalty);
2713 Penalty -= NewBreakPenalty;
2714 }
2715 if (!DryRun)
2716 Token->reflow(NextLineIndex, Whitespaces);
2717 }
2718 }
2719 }
2720
2721 BreakableToken::Split SplitAfterLastLine =
2722 Token->getSplitAfterLastLine(TailOffset);
2723 if (SplitAfterLastLine.first != StringRef::npos) {
2724 LLVM_DEBUG(llvm::dbgs() << "Replacing whitespace after last line.\n");
2725
2726 // We add the last line's penalty here, since that line is going to be split
2727 // now.
2728 Penalty += Style.PenaltyExcessCharacter *
2729 (ContentStartColumn + RemainingTokenColumns - ColumnLimit);
2730
2731 if (!DryRun) {
2732 Token->replaceWhitespaceAfterLastLine(TailOffset, SplitAfterLastLine,
2733 Whitespaces);
2734 }
2735 ContentStartColumn =
2736 Token->getContentStartColumn(Token->getLineCount() - 1, /*Break=*/true);
2737 RemainingTokenColumns = Token->getRemainingLength(
2738 Token->getLineCount() - 1,
2739 TailOffset + SplitAfterLastLine.first + SplitAfterLastLine.second,
2740 ContentStartColumn);
2741 }
2742
2743 State.Column = ContentStartColumn + RemainingTokenColumns -
2744 Current.UnbreakableTailLength;
2745
2746 if (BreakInserted) {
2747 if (!DryRun)
2748 Token->updateAfterBroken(Whitespaces);
2749
2750 // If we break the token inside a parameter list, we need to break before
2751 // the next parameter on all levels, so that the next parameter is clearly
2752 // visible. Line comments already introduce a break.
2753 if (Current.isNot(TT_LineComment))
2754 for (ParenState &Paren : State.Stack)
2755 Paren.BreakBeforeParameter = true;
2756
2757 if (Current.is(TT_BlockComment))
2758 State.NoContinuation = true;
2759
2760 State.Stack.back().LastSpace = StartColumn;
2761 }
2762
2763 Token->updateNextToken(State);
2764
2765 return {Penalty, Exceeded};
2766 }
2767
getColumnLimit(const LineState & State) const2768 unsigned ContinuationIndenter::getColumnLimit(const LineState &State) const {
2769 // In preprocessor directives reserve two chars for trailing " \".
2770 return Style.ColumnLimit - (State.Line->InPPDirective ? 2 : 0);
2771 }
2772
nextIsMultilineString(const LineState & State)2773 bool ContinuationIndenter::nextIsMultilineString(const LineState &State) {
2774 const FormatToken &Current = *State.NextToken;
2775 if (!Current.isStringLiteral() || Current.is(TT_ImplicitStringLiteral))
2776 return false;
2777 // We never consider raw string literals "multiline" for the purpose of
2778 // AlwaysBreakBeforeMultilineStrings implementation as they are special-cased
2779 // (see TokenAnnotator::mustBreakBefore().
2780 if (Current.TokenText.starts_with("R\""))
2781 return false;
2782 if (Current.IsMultiline)
2783 return true;
2784 if (Current.getNextNonComment() &&
2785 Current.getNextNonComment()->isStringLiteral()) {
2786 return true; // Implicit concatenation.
2787 }
2788 if (Style.ColumnLimit != 0 && Style.BreakStringLiterals &&
2789 State.Column + Current.ColumnWidth + Current.UnbreakableTailLength >
2790 Style.ColumnLimit) {
2791 return true; // String will be split.
2792 }
2793 return false;
2794 }
2795
2796 } // namespace format
2797 } // namespace clang
2798