1 //===--- ContinuationIndenter.cpp - Format C++ code -----------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 ///
10 /// \file
11 /// \brief This file implements the continuation indenter.
12 ///
13 //===----------------------------------------------------------------------===//
14
15 #include "BreakableToken.h"
16 #include "ContinuationIndenter.h"
17 #include "WhitespaceManager.h"
18 #include "clang/Basic/OperatorPrecedence.h"
19 #include "clang/Basic/SourceManager.h"
20 #include "clang/Format/Format.h"
21 #include "llvm/Support/Debug.h"
22 #include <string>
23
24 #define DEBUG_TYPE "format-formatter"
25
26 namespace clang {
27 namespace format {
28
29 // Returns the length of everything up to the first possible line break after
30 // the ), ], } or > matching \c Tok.
getLengthToMatchingParen(const FormatToken & Tok)31 static unsigned getLengthToMatchingParen(const FormatToken &Tok) {
32 if (!Tok.MatchingParen)
33 return 0;
34 FormatToken *End = Tok.MatchingParen;
35 while (End->Next && !End->Next->CanBreakBefore) {
36 End = End->Next;
37 }
38 return End->TotalLength - Tok.TotalLength + 1;
39 }
40
41 // Returns \c true if \c Tok is the "." or "->" of a call and starts the next
42 // segment of a builder type call.
startsSegmentOfBuilderTypeCall(const FormatToken & Tok)43 static bool startsSegmentOfBuilderTypeCall(const FormatToken &Tok) {
44 return Tok.isMemberAccess() && Tok.Previous && Tok.Previous->closesScope();
45 }
46
47 // Returns \c true if \c Current starts a new parameter.
startsNextParameter(const FormatToken & Current,const FormatStyle & Style)48 static bool startsNextParameter(const FormatToken &Current,
49 const FormatStyle &Style) {
50 const FormatToken &Previous = *Current.Previous;
51 if (Current.is(TT_CtorInitializerComma) &&
52 Style.BreakConstructorInitializersBeforeComma)
53 return true;
54 return Previous.is(tok::comma) && !Current.isTrailingComment() &&
55 (Previous.isNot(TT_CtorInitializerComma) ||
56 !Style.BreakConstructorInitializersBeforeComma);
57 }
58
ContinuationIndenter(const FormatStyle & Style,const AdditionalKeywords & Keywords,SourceManager & SourceMgr,WhitespaceManager & Whitespaces,encoding::Encoding Encoding,bool BinPackInconclusiveFunctions)59 ContinuationIndenter::ContinuationIndenter(const FormatStyle &Style,
60 const AdditionalKeywords &Keywords,
61 SourceManager &SourceMgr,
62 WhitespaceManager &Whitespaces,
63 encoding::Encoding Encoding,
64 bool BinPackInconclusiveFunctions)
65 : Style(Style), Keywords(Keywords), SourceMgr(SourceMgr),
66 Whitespaces(Whitespaces), Encoding(Encoding),
67 BinPackInconclusiveFunctions(BinPackInconclusiveFunctions),
68 CommentPragmasRegex(Style.CommentPragmas) {}
69
getInitialState(unsigned FirstIndent,const AnnotatedLine * Line,bool DryRun)70 LineState ContinuationIndenter::getInitialState(unsigned FirstIndent,
71 const AnnotatedLine *Line,
72 bool DryRun) {
73 LineState State;
74 State.FirstIndent = FirstIndent;
75 State.Column = FirstIndent;
76 State.Line = Line;
77 State.NextToken = Line->First;
78 State.Stack.push_back(ParenState(FirstIndent, Line->Level, FirstIndent,
79 /*AvoidBinPacking=*/false,
80 /*NoLineBreak=*/false));
81 State.LineContainsContinuedForLoopSection = false;
82 State.StartOfStringLiteral = 0;
83 State.StartOfLineLevel = 0;
84 State.LowestLevelOnLine = 0;
85 State.IgnoreStackForComparison = false;
86
87 // The first token has already been indented and thus consumed.
88 moveStateToNextToken(State, DryRun, /*Newline=*/false);
89 return State;
90 }
91
canBreak(const LineState & State)92 bool ContinuationIndenter::canBreak(const LineState &State) {
93 const FormatToken &Current = *State.NextToken;
94 const FormatToken &Previous = *Current.Previous;
95 assert(&Previous == Current.Previous);
96 if (!Current.CanBreakBefore &&
97 !(State.Stack.back().BreakBeforeClosingBrace &&
98 Current.closesBlockTypeList(Style)))
99 return false;
100 // The opening "{" of a braced list has to be on the same line as the first
101 // element if it is nested in another braced init list or function call.
102 if (!Current.MustBreakBefore && Previous.is(tok::l_brace) &&
103 Previous.isNot(TT_DictLiteral) && Previous.BlockKind == BK_BracedInit &&
104 Previous.Previous &&
105 Previous.Previous->isOneOf(tok::l_brace, tok::l_paren, tok::comma))
106 return false;
107 // This prevents breaks like:
108 // ...
109 // SomeParameter, OtherParameter).DoSomething(
110 // ...
111 // As they hide "DoSomething" and are generally bad for readability.
112 if (Previous.opensScope() && Previous.isNot(tok::l_brace) &&
113 State.LowestLevelOnLine < State.StartOfLineLevel &&
114 State.LowestLevelOnLine < Current.NestingLevel)
115 return false;
116 if (Current.isMemberAccess() && State.Stack.back().ContainsUnwrappedBuilder)
117 return false;
118
119 // Don't create a 'hanging' indent if there are multiple blocks in a single
120 // statement.
121 if (Previous.is(tok::l_brace) && State.Stack.size() > 1 &&
122 State.Stack[State.Stack.size() - 2].NestedBlockInlined &&
123 State.Stack[State.Stack.size() - 2].HasMultipleNestedBlocks)
124 return false;
125
126 // Don't break after very short return types (e.g. "void") as that is often
127 // unexpected.
128 if (Current.is(TT_FunctionDeclarationName) &&
129 !Style.AlwaysBreakAfterDefinitionReturnType && State.Column < 6)
130 return false;
131
132 return !State.Stack.back().NoLineBreak;
133 }
134
mustBreak(const LineState & State)135 bool ContinuationIndenter::mustBreak(const LineState &State) {
136 const FormatToken &Current = *State.NextToken;
137 const FormatToken &Previous = *Current.Previous;
138 if (Current.MustBreakBefore || Current.is(TT_InlineASMColon))
139 return true;
140 if (State.Stack.back().BreakBeforeClosingBrace &&
141 Current.closesBlockTypeList(Style))
142 return true;
143 if (Previous.is(tok::semi) && State.LineContainsContinuedForLoopSection)
144 return true;
145 if ((startsNextParameter(Current, Style) || Previous.is(tok::semi) ||
146 (Style.BreakBeforeTernaryOperators &&
147 (Current.is(tok::question) ||
148 (Current.is(TT_ConditionalExpr) && Previous.isNot(tok::question)))) ||
149 (!Style.BreakBeforeTernaryOperators &&
150 (Previous.is(tok::question) || Previous.is(TT_ConditionalExpr)))) &&
151 State.Stack.back().BreakBeforeParameter && !Current.isTrailingComment() &&
152 !Current.isOneOf(tok::r_paren, tok::r_brace))
153 return true;
154 if (Style.AlwaysBreakBeforeMultilineStrings &&
155 State.Column > State.Stack.back().Indent && // Breaking saves columns.
156 !Previous.isOneOf(tok::kw_return, tok::lessless, tok::at) &&
157 !Previous.isOneOf(TT_InlineASMColon, TT_ConditionalExpr) &&
158 nextIsMultilineString(State))
159 return true;
160 if (((Previous.is(TT_DictLiteral) && Previous.is(tok::l_brace)) ||
161 Previous.is(TT_ArrayInitializerLSquare)) &&
162 Style.ColumnLimit > 0 &&
163 getLengthToMatchingParen(Previous) + State.Column > getColumnLimit(State))
164 return true;
165 if (Current.is(TT_CtorInitializerColon) &&
166 ((Style.AllowShortFunctionsOnASingleLine != FormatStyle::SFS_All) ||
167 Style.BreakConstructorInitializersBeforeComma || Style.ColumnLimit != 0))
168 return true;
169
170 if (State.Column < getNewLineColumn(State))
171 return false;
172 if (Style.BreakBeforeBinaryOperators == FormatStyle::BOS_None) {
173 // If we need to break somewhere inside the LHS of a binary expression, we
174 // should also break after the operator. Otherwise, the formatting would
175 // hide the operator precedence, e.g. in:
176 // if (aaaaaaaaaaaaaa ==
177 // bbbbbbbbbbbbbb && c) {..
178 // For comparisons, we only apply this rule, if the LHS is a binary
179 // expression itself as otherwise, the line breaks seem superfluous.
180 // We need special cases for ">>" which we have split into two ">" while
181 // lexing in order to make template parsing easier.
182 bool IsComparison = (Previous.getPrecedence() == prec::Relational ||
183 Previous.getPrecedence() == prec::Equality) &&
184 Previous.Previous &&
185 Previous.Previous->isNot(TT_BinaryOperator); // For >>.
186 bool LHSIsBinaryExpr =
187 Previous.Previous && Previous.Previous->EndsBinaryExpression;
188 if (Previous.is(TT_BinaryOperator) && (!IsComparison || LHSIsBinaryExpr) &&
189 Current.isNot(TT_BinaryOperator) && // For >>.
190 !Current.isTrailingComment() && !Previous.is(tok::lessless) &&
191 Previous.getPrecedence() != prec::Assignment &&
192 State.Stack.back().BreakBeforeParameter)
193 return true;
194 } else {
195 if (Current.is(TT_BinaryOperator) && Previous.EndsBinaryExpression &&
196 State.Stack.back().BreakBeforeParameter)
197 return true;
198 }
199
200 // Same as above, but for the first "<<" operator.
201 if (Current.is(tok::lessless) && Current.isNot(TT_OverloadedOperator) &&
202 State.Stack.back().BreakBeforeParameter &&
203 State.Stack.back().FirstLessLess == 0)
204 return true;
205
206 if (Current.is(TT_SelectorName) && State.Stack.back().ObjCSelectorNameFound &&
207 State.Stack.back().BreakBeforeParameter)
208 return true;
209 if (Current.NestingLevel == 0 && !Current.isTrailingComment()) {
210 if (Previous.ClosesTemplateDeclaration)
211 return true;
212 if (Previous.is(TT_LeadingJavaAnnotation) && Current.isNot(tok::l_paren) &&
213 Current.isNot(TT_LeadingJavaAnnotation))
214 return true;
215 }
216
217 // If the return type spans multiple lines, wrap before the function name.
218 if (Current.isOneOf(TT_FunctionDeclarationName, tok::kw_operator) &&
219 State.Stack.back().BreakBeforeParameter)
220 return true;
221
222 if (startsSegmentOfBuilderTypeCall(Current) &&
223 (State.Stack.back().CallContinuation != 0 ||
224 State.Stack.back().BreakBeforeParameter))
225 return true;
226
227 // The following could be precomputed as they do not depend on the state.
228 // However, as they should take effect only if the UnwrappedLine does not fit
229 // into the ColumnLimit, they are checked here in the ContinuationIndenter.
230 if (Style.ColumnLimit != 0 && Previous.BlockKind == BK_Block &&
231 Previous.is(tok::l_brace) && !Current.isOneOf(tok::r_brace, tok::comment))
232 return true;
233
234 if (Current.is(tok::lessless) && Previous.is(tok::identifier) &&
235 Previous.TokenText == "endl")
236 return true;
237
238 return false;
239 }
240
addTokenToState(LineState & State,bool Newline,bool DryRun,unsigned ExtraSpaces)241 unsigned ContinuationIndenter::addTokenToState(LineState &State, bool Newline,
242 bool DryRun,
243 unsigned ExtraSpaces) {
244 const FormatToken &Current = *State.NextToken;
245
246 assert(!State.Stack.empty());
247 if ((Current.is(TT_ImplicitStringLiteral) &&
248 (Current.Previous->Tok.getIdentifierInfo() == nullptr ||
249 Current.Previous->Tok.getIdentifierInfo()->getPPKeywordID() ==
250 tok::pp_not_keyword))) {
251 unsigned EndColumn =
252 SourceMgr.getSpellingColumnNumber(Current.WhitespaceRange.getEnd());
253 if (Current.LastNewlineOffset != 0) {
254 // If there is a newline within this token, the final column will solely
255 // determined by the current end column.
256 State.Column = EndColumn;
257 } else {
258 unsigned StartColumn =
259 SourceMgr.getSpellingColumnNumber(Current.WhitespaceRange.getBegin());
260 assert(EndColumn >= StartColumn);
261 State.Column += EndColumn - StartColumn;
262 }
263 moveStateToNextToken(State, DryRun, /*Newline=*/false);
264 return 0;
265 }
266
267 unsigned Penalty = 0;
268 if (Newline)
269 Penalty = addTokenOnNewLine(State, DryRun);
270 else
271 addTokenOnCurrentLine(State, DryRun, ExtraSpaces);
272
273 return moveStateToNextToken(State, DryRun, Newline) + Penalty;
274 }
275
addTokenOnCurrentLine(LineState & State,bool DryRun,unsigned ExtraSpaces)276 void ContinuationIndenter::addTokenOnCurrentLine(LineState &State, bool DryRun,
277 unsigned ExtraSpaces) {
278 FormatToken &Current = *State.NextToken;
279 const FormatToken &Previous = *State.NextToken->Previous;
280 if (Current.is(tok::equal) &&
281 (State.Line->First->is(tok::kw_for) || Current.NestingLevel == 0) &&
282 State.Stack.back().VariablePos == 0) {
283 State.Stack.back().VariablePos = State.Column;
284 // Move over * and & if they are bound to the variable name.
285 const FormatToken *Tok = &Previous;
286 while (Tok && State.Stack.back().VariablePos >= Tok->ColumnWidth) {
287 State.Stack.back().VariablePos -= Tok->ColumnWidth;
288 if (Tok->SpacesRequiredBefore != 0)
289 break;
290 Tok = Tok->Previous;
291 }
292 if (Previous.PartOfMultiVariableDeclStmt)
293 State.Stack.back().LastSpace = State.Stack.back().VariablePos;
294 }
295
296 unsigned Spaces = Current.SpacesRequiredBefore + ExtraSpaces;
297
298 if (!DryRun)
299 Whitespaces.replaceWhitespace(Current, /*Newlines=*/0, /*IndentLevel=*/0,
300 Spaces, State.Column + Spaces);
301
302 if (Current.is(TT_SelectorName) &&
303 !State.Stack.back().ObjCSelectorNameFound) {
304 if (Current.LongestObjCSelectorName == 0)
305 State.Stack.back().AlignColons = false;
306 else if (State.Stack.back().Indent + Current.LongestObjCSelectorName >
307 State.Column + Spaces + Current.ColumnWidth)
308 State.Stack.back().ColonPos =
309 std::max(State.FirstIndent + Style.ContinuationIndentWidth,
310 State.Stack.back().Indent) +
311 Current.LongestObjCSelectorName;
312 else
313 State.Stack.back().ColonPos = State.Column + Spaces + Current.ColumnWidth;
314 }
315
316 if (Style.AlignAfterOpenBracket && Previous.opensScope() &&
317 Previous.isNot(TT_ObjCMethodExpr) &&
318 (Current.isNot(TT_LineComment) || Previous.BlockKind == BK_BracedInit))
319 State.Stack.back().Indent = State.Column + Spaces;
320 if (State.Stack.back().AvoidBinPacking && startsNextParameter(Current, Style))
321 State.Stack.back().NoLineBreak = true;
322 if (startsSegmentOfBuilderTypeCall(Current))
323 State.Stack.back().ContainsUnwrappedBuilder = true;
324
325 if (Current.is(TT_LambdaArrow))
326 State.Stack.back().NoLineBreak = true;
327 if (Current.isMemberAccess() && Previous.is(tok::r_paren) &&
328 (Previous.MatchingParen &&
329 (Previous.TotalLength - Previous.MatchingParen->TotalLength > 10))) {
330 // If there is a function call with long parameters, break before trailing
331 // calls. This prevents things like:
332 // EXPECT_CALL(SomeLongParameter).Times(
333 // 2);
334 // We don't want to do this for short parameters as they can just be
335 // indexes.
336 State.Stack.back().NoLineBreak = true;
337 }
338
339 State.Column += Spaces;
340 if (Current.isNot(tok::comment) && Previous.is(tok::l_paren) &&
341 Previous.Previous &&
342 Previous.Previous->isOneOf(tok::kw_if, tok::kw_for)) {
343 // Treat the condition inside an if as if it was a second function
344 // parameter, i.e. let nested calls have a continuation indent.
345 State.Stack.back().LastSpace = State.Column;
346 State.Stack.back().NestedBlockIndent = State.Column;
347 } else if (!Current.isOneOf(tok::comment, tok::caret) &&
348 (Previous.is(tok::comma) ||
349 (Previous.is(tok::colon) && Previous.is(TT_ObjCMethodExpr)))) {
350 State.Stack.back().LastSpace = State.Column;
351 } else if ((Previous.isOneOf(TT_BinaryOperator, TT_ConditionalExpr,
352 TT_CtorInitializerColon)) &&
353 ((Previous.getPrecedence() != prec::Assignment &&
354 (Previous.isNot(tok::lessless) || Previous.OperatorIndex != 0 ||
355 !Previous.LastOperator)) ||
356 Current.StartsBinaryExpression)) {
357 // Always indent relative to the RHS of the expression unless this is a
358 // simple assignment without binary expression on the RHS. Also indent
359 // relative to unary operators and the colons of constructor initializers.
360 State.Stack.back().LastSpace = State.Column;
361 } else if (Previous.is(TT_InheritanceColon)) {
362 State.Stack.back().Indent = State.Column;
363 State.Stack.back().LastSpace = State.Column;
364 } else if (Previous.opensScope()) {
365 // If a function has a trailing call, indent all parameters from the
366 // opening parenthesis. This avoids confusing indents like:
367 // OuterFunction(InnerFunctionCall( // break
368 // ParameterToInnerFunction)) // break
369 // .SecondInnerFunctionCall();
370 bool HasTrailingCall = false;
371 if (Previous.MatchingParen) {
372 const FormatToken *Next = Previous.MatchingParen->getNextNonComment();
373 HasTrailingCall = Next && Next->isMemberAccess();
374 }
375 if (HasTrailingCall && State.Stack.size() > 1 &&
376 State.Stack[State.Stack.size() - 2].CallContinuation == 0)
377 State.Stack.back().LastSpace = State.Column;
378 }
379 }
380
addTokenOnNewLine(LineState & State,bool DryRun)381 unsigned ContinuationIndenter::addTokenOnNewLine(LineState &State,
382 bool DryRun) {
383 FormatToken &Current = *State.NextToken;
384 const FormatToken &Previous = *State.NextToken->Previous;
385
386 // Extra penalty that needs to be added because of the way certain line
387 // breaks are chosen.
388 unsigned Penalty = 0;
389
390 const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
391 const FormatToken *NextNonComment = Previous.getNextNonComment();
392 if (!NextNonComment)
393 NextNonComment = &Current;
394 // The first line break on any NestingLevel causes an extra penalty in order
395 // prefer similar line breaks.
396 if (!State.Stack.back().ContainsLineBreak)
397 Penalty += 15;
398 State.Stack.back().ContainsLineBreak = true;
399
400 Penalty += State.NextToken->SplitPenalty;
401
402 // Breaking before the first "<<" is generally not desirable if the LHS is
403 // short. Also always add the penalty if the LHS is split over mutliple lines
404 // to avoid unnecessary line breaks that just work around this penalty.
405 if (NextNonComment->is(tok::lessless) &&
406 State.Stack.back().FirstLessLess == 0 &&
407 (State.Column <= Style.ColumnLimit / 3 ||
408 State.Stack.back().BreakBeforeParameter))
409 Penalty += Style.PenaltyBreakFirstLessLess;
410
411 State.Column = getNewLineColumn(State);
412 State.Stack.back().NestedBlockIndent = State.Column;
413 if (NextNonComment->isMemberAccess()) {
414 if (State.Stack.back().CallContinuation == 0)
415 State.Stack.back().CallContinuation = State.Column;
416 } else if (NextNonComment->is(TT_SelectorName)) {
417 if (!State.Stack.back().ObjCSelectorNameFound) {
418 if (NextNonComment->LongestObjCSelectorName == 0) {
419 State.Stack.back().AlignColons = false;
420 } else {
421 State.Stack.back().ColonPos =
422 State.Stack.back().Indent + NextNonComment->LongestObjCSelectorName;
423 }
424 } else if (State.Stack.back().AlignColons &&
425 State.Stack.back().ColonPos <= NextNonComment->ColumnWidth) {
426 State.Stack.back().ColonPos = State.Column + NextNonComment->ColumnWidth;
427 }
428 } else if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
429 PreviousNonComment->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral)) {
430 // FIXME: This is hacky, find a better way. The problem is that in an ObjC
431 // method expression, the block should be aligned to the line starting it,
432 // e.g.:
433 // [aaaaaaaaaaaaaaa aaaaaaaaa: \\ break for some reason
434 // ^(int *i) {
435 // // ...
436 // }];
437 // Thus, we set LastSpace of the next higher NestingLevel, to which we move
438 // when we consume all of the "}"'s FakeRParens at the "{".
439 if (State.Stack.size() > 1)
440 State.Stack[State.Stack.size() - 2].LastSpace =
441 std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) +
442 Style.ContinuationIndentWidth;
443 }
444
445 if ((Previous.isOneOf(tok::comma, tok::semi) &&
446 !State.Stack.back().AvoidBinPacking) ||
447 Previous.is(TT_BinaryOperator))
448 State.Stack.back().BreakBeforeParameter = false;
449 if (Previous.isOneOf(TT_TemplateCloser, TT_JavaAnnotation) &&
450 Current.NestingLevel == 0)
451 State.Stack.back().BreakBeforeParameter = false;
452 if (NextNonComment->is(tok::question) ||
453 (PreviousNonComment && PreviousNonComment->is(tok::question)))
454 State.Stack.back().BreakBeforeParameter = true;
455
456 if (!DryRun) {
457 unsigned Newlines = std::max(
458 1u, std::min(Current.NewlinesBefore, Style.MaxEmptyLinesToKeep + 1));
459 Whitespaces.replaceWhitespace(Current, Newlines,
460 State.Stack.back().IndentLevel, State.Column,
461 State.Column, State.Line->InPPDirective);
462 }
463
464 if (!Current.isTrailingComment())
465 State.Stack.back().LastSpace = State.Column;
466 State.StartOfLineLevel = Current.NestingLevel;
467 State.LowestLevelOnLine = Current.NestingLevel;
468
469 // Any break on this level means that the parent level has been broken
470 // and we need to avoid bin packing there.
471 bool NestedBlockSpecialCase =
472 Current.is(tok::r_brace) && State.Stack.size() > 1 &&
473 State.Stack[State.Stack.size() - 2].NestedBlockInlined;
474 if (!NestedBlockSpecialCase) {
475 for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i) {
476 State.Stack[i].BreakBeforeParameter = true;
477 }
478 }
479
480 if (PreviousNonComment &&
481 !PreviousNonComment->isOneOf(tok::comma, tok::semi) &&
482 (PreviousNonComment->isNot(TT_TemplateCloser) ||
483 Current.NestingLevel != 0) &&
484 !PreviousNonComment->isOneOf(TT_BinaryOperator, TT_JavaAnnotation,
485 TT_LeadingJavaAnnotation) &&
486 Current.isNot(TT_BinaryOperator) && !PreviousNonComment->opensScope())
487 State.Stack.back().BreakBeforeParameter = true;
488
489 // If we break after { or the [ of an array initializer, we should also break
490 // before the corresponding } or ].
491 if (PreviousNonComment &&
492 (PreviousNonComment->isOneOf(tok::l_brace, TT_ArrayInitializerLSquare)))
493 State.Stack.back().BreakBeforeClosingBrace = true;
494
495 if (State.Stack.back().AvoidBinPacking) {
496 // If we are breaking after '(', '{', '<', this is not bin packing
497 // unless AllowAllParametersOfDeclarationOnNextLine is false or this is a
498 // dict/object literal.
499 if (!Previous.isOneOf(tok::l_paren, tok::l_brace, TT_BinaryOperator) ||
500 (!Style.AllowAllParametersOfDeclarationOnNextLine &&
501 State.Line->MustBeDeclaration) ||
502 Previous.is(TT_DictLiteral))
503 State.Stack.back().BreakBeforeParameter = true;
504 }
505
506 return Penalty;
507 }
508
getNewLineColumn(const LineState & State)509 unsigned ContinuationIndenter::getNewLineColumn(const LineState &State) {
510 if (!State.NextToken || !State.NextToken->Previous)
511 return 0;
512 FormatToken &Current = *State.NextToken;
513 const FormatToken &Previous = *Current.Previous;
514 // If we are continuing an expression, we want to use the continuation indent.
515 unsigned ContinuationIndent =
516 std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) +
517 Style.ContinuationIndentWidth;
518 const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
519 const FormatToken *NextNonComment = Previous.getNextNonComment();
520 if (!NextNonComment)
521 NextNonComment = &Current;
522
523 // Java specific bits.
524 if (Style.Language == FormatStyle::LK_Java &&
525 Current.isOneOf(Keywords.kw_implements, Keywords.kw_extends))
526 return std::max(State.Stack.back().LastSpace,
527 State.Stack.back().Indent + Style.ContinuationIndentWidth);
528
529 if (NextNonComment->is(tok::l_brace) && NextNonComment->BlockKind == BK_Block)
530 return Current.NestingLevel == 0 ? State.FirstIndent
531 : State.Stack.back().Indent;
532 if (Current.isOneOf(tok::r_brace, tok::r_square) && State.Stack.size() > 1) {
533 if (Current.closesBlockTypeList(Style))
534 return State.Stack[State.Stack.size() - 2].NestedBlockIndent;
535 if (Current.MatchingParen &&
536 Current.MatchingParen->BlockKind == BK_BracedInit)
537 return State.Stack[State.Stack.size() - 2].LastSpace;
538 return State.FirstIndent;
539 }
540 if (Current.is(tok::identifier) && Current.Next &&
541 Current.Next->is(TT_DictLiteral))
542 return State.Stack.back().Indent;
543 if (NextNonComment->isStringLiteral() && State.StartOfStringLiteral != 0)
544 return State.StartOfStringLiteral;
545 if (NextNonComment->is(tok::lessless) &&
546 State.Stack.back().FirstLessLess != 0)
547 return State.Stack.back().FirstLessLess;
548 if (NextNonComment->isMemberAccess()) {
549 if (State.Stack.back().CallContinuation == 0)
550 return ContinuationIndent;
551 return State.Stack.back().CallContinuation;
552 }
553 if (State.Stack.back().QuestionColumn != 0 &&
554 ((NextNonComment->is(tok::colon) &&
555 NextNonComment->is(TT_ConditionalExpr)) ||
556 Previous.is(TT_ConditionalExpr)))
557 return State.Stack.back().QuestionColumn;
558 if (Previous.is(tok::comma) && State.Stack.back().VariablePos != 0)
559 return State.Stack.back().VariablePos;
560 if ((PreviousNonComment &&
561 (PreviousNonComment->ClosesTemplateDeclaration ||
562 PreviousNonComment->isOneOf(TT_AttributeParen, TT_JavaAnnotation,
563 TT_LeadingJavaAnnotation))) ||
564 (!Style.IndentWrappedFunctionNames &&
565 NextNonComment->isOneOf(tok::kw_operator, TT_FunctionDeclarationName)))
566 return std::max(State.Stack.back().LastSpace, State.Stack.back().Indent);
567 if (NextNonComment->is(TT_SelectorName)) {
568 if (!State.Stack.back().ObjCSelectorNameFound) {
569 if (NextNonComment->LongestObjCSelectorName == 0)
570 return State.Stack.back().Indent;
571 return State.Stack.back().Indent +
572 NextNonComment->LongestObjCSelectorName -
573 NextNonComment->ColumnWidth;
574 }
575 if (!State.Stack.back().AlignColons)
576 return State.Stack.back().Indent;
577 if (State.Stack.back().ColonPos > NextNonComment->ColumnWidth)
578 return State.Stack.back().ColonPos - NextNonComment->ColumnWidth;
579 return State.Stack.back().Indent;
580 }
581 if (NextNonComment->is(TT_ArraySubscriptLSquare)) {
582 if (State.Stack.back().StartOfArraySubscripts != 0)
583 return State.Stack.back().StartOfArraySubscripts;
584 return ContinuationIndent;
585 }
586 if (NextNonComment->isOneOf(TT_StartOfName, TT_PointerOrReference) ||
587 Previous.isOneOf(tok::coloncolon, tok::equal)) {
588 return ContinuationIndent;
589 }
590 if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
591 PreviousNonComment->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral))
592 return ContinuationIndent;
593 if (NextNonComment->is(TT_CtorInitializerColon))
594 return State.FirstIndent + Style.ConstructorInitializerIndentWidth;
595 if (NextNonComment->is(TT_CtorInitializerComma))
596 return State.Stack.back().Indent;
597 if (Previous.is(tok::r_paren) && !Current.isBinaryOperator() &&
598 !Current.isOneOf(tok::colon, tok::comment))
599 return ContinuationIndent;
600 if (State.Stack.back().Indent == State.FirstIndent && PreviousNonComment &&
601 PreviousNonComment->isNot(tok::r_brace))
602 // Ensure that we fall back to the continuation indent width instead of
603 // just flushing continuations left.
604 return State.Stack.back().Indent + Style.ContinuationIndentWidth;
605 return State.Stack.back().Indent;
606 }
607
moveStateToNextToken(LineState & State,bool DryRun,bool Newline)608 unsigned ContinuationIndenter::moveStateToNextToken(LineState &State,
609 bool DryRun, bool Newline) {
610 assert(State.Stack.size());
611 const FormatToken &Current = *State.NextToken;
612
613 if (Current.is(TT_InheritanceColon))
614 State.Stack.back().AvoidBinPacking = true;
615 if (Current.is(tok::lessless) && Current.isNot(TT_OverloadedOperator)) {
616 if (State.Stack.back().FirstLessLess == 0)
617 State.Stack.back().FirstLessLess = State.Column;
618 else
619 State.Stack.back().LastOperatorWrapped = Newline;
620 }
621 if ((Current.is(TT_BinaryOperator) && Current.isNot(tok::lessless)) ||
622 Current.is(TT_ConditionalExpr))
623 State.Stack.back().LastOperatorWrapped = Newline;
624 if (Current.is(TT_ArraySubscriptLSquare) &&
625 State.Stack.back().StartOfArraySubscripts == 0)
626 State.Stack.back().StartOfArraySubscripts = State.Column;
627 if ((Current.is(tok::question) && Style.BreakBeforeTernaryOperators) ||
628 (Current.getPreviousNonComment() && Current.isNot(tok::colon) &&
629 Current.getPreviousNonComment()->is(tok::question) &&
630 !Style.BreakBeforeTernaryOperators))
631 State.Stack.back().QuestionColumn = State.Column;
632 if (!Current.opensScope() && !Current.closesScope())
633 State.LowestLevelOnLine =
634 std::min(State.LowestLevelOnLine, Current.NestingLevel);
635 if (Current.isMemberAccess())
636 State.Stack.back().StartOfFunctionCall =
637 Current.LastOperator ? 0 : State.Column;
638 if (Current.is(TT_SelectorName))
639 State.Stack.back().ObjCSelectorNameFound = true;
640 if (Current.is(TT_CtorInitializerColon)) {
641 // Indent 2 from the column, so:
642 // SomeClass::SomeClass()
643 // : First(...), ...
644 // Next(...)
645 // ^ line up here.
646 State.Stack.back().Indent =
647 State.Column + (Style.BreakConstructorInitializersBeforeComma ? 0 : 2);
648 State.Stack.back().NestedBlockIndent = State.Stack.back().Indent;
649 if (Style.ConstructorInitializerAllOnOneLineOrOnePerLine)
650 State.Stack.back().AvoidBinPacking = true;
651 State.Stack.back().BreakBeforeParameter = false;
652 }
653
654 // Insert scopes created by fake parenthesis.
655 const FormatToken *Previous = Current.getPreviousNonComment();
656
657 // Add special behavior to support a format commonly used for JavaScript
658 // closures:
659 // SomeFunction(function() {
660 // foo();
661 // bar();
662 // }, a, b, c);
663 if (Current.isNot(tok::comment) && Previous && Previous->is(tok::l_brace) &&
664 State.Stack.size() > 1) {
665 if (State.Stack[State.Stack.size() - 2].NestedBlockInlined && Newline) {
666 for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i) {
667 State.Stack[i].NoLineBreak = true;
668 }
669 }
670 State.Stack[State.Stack.size() - 2].NestedBlockInlined = false;
671 }
672 if (Previous && (Previous->isOneOf(tok::l_paren, tok::comma, tok::colon) ||
673 Previous->isOneOf(TT_BinaryOperator, TT_ConditionalExpr)) &&
674 !Previous->isOneOf(TT_DictLiteral, TT_ObjCMethodExpr)) {
675 State.Stack.back().NestedBlockInlined =
676 !Newline &&
677 (Previous->isNot(tok::l_paren) || Previous->ParameterCount > 1);
678 }
679
680 moveStatePastFakeLParens(State, Newline);
681 moveStatePastScopeOpener(State, Newline);
682 moveStatePastScopeCloser(State);
683 moveStatePastFakeRParens(State);
684
685 if (Current.isStringLiteral() && State.StartOfStringLiteral == 0) {
686 State.StartOfStringLiteral = State.Column;
687 } else if (!Current.isOneOf(tok::comment, tok::identifier, tok::hash) &&
688 !Current.isStringLiteral()) {
689 State.StartOfStringLiteral = 0;
690 }
691
692 State.Column += Current.ColumnWidth;
693 State.NextToken = State.NextToken->Next;
694 unsigned Penalty = breakProtrudingToken(Current, State, DryRun);
695 if (State.Column > getColumnLimit(State)) {
696 unsigned ExcessCharacters = State.Column - getColumnLimit(State);
697 Penalty += Style.PenaltyExcessCharacter * ExcessCharacters;
698 }
699
700 if (Current.Role)
701 Current.Role->formatFromToken(State, this, DryRun);
702 // If the previous has a special role, let it consume tokens as appropriate.
703 // It is necessary to start at the previous token for the only implemented
704 // role (comma separated list). That way, the decision whether or not to break
705 // after the "{" is already done and both options are tried and evaluated.
706 // FIXME: This is ugly, find a better way.
707 if (Previous && Previous->Role)
708 Penalty += Previous->Role->formatAfterToken(State, this, DryRun);
709
710 return Penalty;
711 }
712
moveStatePastFakeLParens(LineState & State,bool Newline)713 void ContinuationIndenter::moveStatePastFakeLParens(LineState &State,
714 bool Newline) {
715 const FormatToken &Current = *State.NextToken;
716 const FormatToken *Previous = Current.getPreviousNonComment();
717
718 // Don't add extra indentation for the first fake parenthesis after
719 // 'return', assignments or opening <({[. The indentation for these cases
720 // is special cased.
721 bool SkipFirstExtraIndent =
722 (Previous && (Previous->opensScope() ||
723 Previous->isOneOf(tok::semi, tok::kw_return) ||
724 (Previous->getPrecedence() == prec::Assignment &&
725 Style.AlignOperands) ||
726 Previous->is(TT_ObjCMethodExpr)));
727 for (SmallVectorImpl<prec::Level>::const_reverse_iterator
728 I = Current.FakeLParens.rbegin(),
729 E = Current.FakeLParens.rend();
730 I != E; ++I) {
731 ParenState NewParenState = State.Stack.back();
732 NewParenState.ContainsLineBreak = false;
733
734 // Indent from 'LastSpace' unless these are fake parentheses encapsulating
735 // a builder type call after 'return' or, if the alignment after opening
736 // brackets is disabled.
737 if (!Current.isTrailingComment() &&
738 (Style.AlignOperands || *I < prec::Assignment) &&
739 (!Previous || Previous->isNot(tok::kw_return) ||
740 (Style.Language != FormatStyle::LK_Java && *I > 0)) &&
741 (Style.AlignAfterOpenBracket || *I != prec::Comma ||
742 Current.NestingLevel == 0))
743 NewParenState.Indent =
744 std::max(std::max(State.Column, NewParenState.Indent),
745 State.Stack.back().LastSpace);
746
747 // Don't allow the RHS of an operator to be split over multiple lines unless
748 // there is a line-break right after the operator.
749 // Exclude relational operators, as there, it is always more desirable to
750 // have the LHS 'left' of the RHS.
751 if (Previous && Previous->getPrecedence() > prec::Assignment &&
752 Previous->isOneOf(TT_BinaryOperator, TT_ConditionalExpr) &&
753 Previous->getPrecedence() != prec::Relational) {
754 bool BreakBeforeOperator =
755 Previous->is(tok::lessless) ||
756 (Previous->is(TT_BinaryOperator) &&
757 Style.BreakBeforeBinaryOperators != FormatStyle::BOS_None) ||
758 (Previous->is(TT_ConditionalExpr) &&
759 Style.BreakBeforeTernaryOperators);
760 if ((!Newline && !BreakBeforeOperator) ||
761 (!State.Stack.back().LastOperatorWrapped && BreakBeforeOperator))
762 NewParenState.NoLineBreak = true;
763 }
764
765 // Do not indent relative to the fake parentheses inserted for "." or "->".
766 // This is a special case to make the following to statements consistent:
767 // OuterFunction(InnerFunctionCall( // break
768 // ParameterToInnerFunction));
769 // OuterFunction(SomeObject.InnerFunctionCall( // break
770 // ParameterToInnerFunction));
771 if (*I > prec::Unknown)
772 NewParenState.LastSpace = std::max(NewParenState.LastSpace, State.Column);
773 if (*I != prec::Conditional)
774 NewParenState.StartOfFunctionCall = State.Column;
775
776 // Always indent conditional expressions. Never indent expression where
777 // the 'operator' is ',', ';' or an assignment (i.e. *I <=
778 // prec::Assignment) as those have different indentation rules. Indent
779 // other expression, unless the indentation needs to be skipped.
780 if (*I == prec::Conditional ||
781 (!SkipFirstExtraIndent && *I > prec::Assignment &&
782 !Current.isTrailingComment()))
783 NewParenState.Indent += Style.ContinuationIndentWidth;
784 if ((Previous && !Previous->opensScope()) || *I > prec::Comma)
785 NewParenState.BreakBeforeParameter = false;
786 State.Stack.push_back(NewParenState);
787 SkipFirstExtraIndent = false;
788 }
789 }
790
moveStatePastFakeRParens(LineState & State)791 void ContinuationIndenter::moveStatePastFakeRParens(LineState &State) {
792 for (unsigned i = 0, e = State.NextToken->FakeRParens; i != e; ++i) {
793 unsigned VariablePos = State.Stack.back().VariablePos;
794 if (State.Stack.size() == 1) {
795 // Do not pop the last element.
796 break;
797 }
798 State.Stack.pop_back();
799 State.Stack.back().VariablePos = VariablePos;
800 }
801 }
802
moveStatePastScopeOpener(LineState & State,bool Newline)803 void ContinuationIndenter::moveStatePastScopeOpener(LineState &State,
804 bool Newline) {
805 const FormatToken &Current = *State.NextToken;
806 if (!Current.opensScope())
807 return;
808
809 if (Current.MatchingParen && Current.BlockKind == BK_Block) {
810 moveStateToNewBlock(State);
811 return;
812 }
813
814 unsigned NewIndent;
815 unsigned NewIndentLevel = State.Stack.back().IndentLevel;
816 bool AvoidBinPacking;
817 bool BreakBeforeParameter = false;
818 if (Current.isOneOf(tok::l_brace, TT_ArrayInitializerLSquare)) {
819 if (Current.opensBlockTypeList(Style)) {
820 NewIndent = State.Stack.back().NestedBlockIndent + Style.IndentWidth;
821 NewIndent = std::min(State.Column + 2, NewIndent);
822 ++NewIndentLevel;
823 } else {
824 NewIndent = State.Stack.back().LastSpace + Style.ContinuationIndentWidth;
825 }
826 const FormatToken *NextNoComment = Current.getNextNonComment();
827 AvoidBinPacking =
828 Current.isOneOf(TT_ArrayInitializerLSquare, TT_DictLiteral) ||
829 Style.Language == FormatStyle::LK_Proto || !Style.BinPackParameters ||
830 (NextNoComment && NextNoComment->is(TT_DesignatedInitializerPeriod));
831 } else {
832 NewIndent = Style.ContinuationIndentWidth +
833 std::max(State.Stack.back().LastSpace,
834 State.Stack.back().StartOfFunctionCall);
835 AvoidBinPacking =
836 (State.Line->MustBeDeclaration && !Style.BinPackParameters) ||
837 (!State.Line->MustBeDeclaration && !Style.BinPackArguments) ||
838 (Style.ExperimentalAutoDetectBinPacking &&
839 (Current.PackingKind == PPK_OnePerLine ||
840 (!BinPackInconclusiveFunctions &&
841 Current.PackingKind == PPK_Inconclusive)));
842 // If this '[' opens an ObjC call, determine whether all parameters fit
843 // into one line and put one per line if they don't.
844 if (Current.is(TT_ObjCMethodExpr) && Style.ColumnLimit != 0 &&
845 getLengthToMatchingParen(Current) + State.Column >
846 getColumnLimit(State))
847 BreakBeforeParameter = true;
848 }
849 bool NoLineBreak = State.Stack.back().NoLineBreak ||
850 (Current.is(TT_TemplateOpener) &&
851 State.Stack.back().ContainsUnwrappedBuilder);
852 unsigned NestedBlockIndent = std::max(State.Stack.back().StartOfFunctionCall,
853 State.Stack.back().NestedBlockIndent);
854 State.Stack.push_back(ParenState(NewIndent, NewIndentLevel,
855 State.Stack.back().LastSpace,
856 AvoidBinPacking, NoLineBreak));
857 State.Stack.back().NestedBlockIndent = NestedBlockIndent;
858 State.Stack.back().BreakBeforeParameter = BreakBeforeParameter;
859 State.Stack.back().HasMultipleNestedBlocks = Current.BlockParameterCount > 1;
860 }
861
moveStatePastScopeCloser(LineState & State)862 void ContinuationIndenter::moveStatePastScopeCloser(LineState &State) {
863 const FormatToken &Current = *State.NextToken;
864 if (!Current.closesScope())
865 return;
866
867 // If we encounter a closing ), ], } or >, we can remove a level from our
868 // stacks.
869 if (State.Stack.size() > 1 &&
870 (Current.isOneOf(tok::r_paren, tok::r_square) ||
871 (Current.is(tok::r_brace) && State.NextToken != State.Line->First) ||
872 State.NextToken->is(TT_TemplateCloser)))
873 State.Stack.pop_back();
874
875 if (Current.is(tok::r_square)) {
876 // If this ends the array subscript expr, reset the corresponding value.
877 const FormatToken *NextNonComment = Current.getNextNonComment();
878 if (NextNonComment && NextNonComment->isNot(tok::l_square))
879 State.Stack.back().StartOfArraySubscripts = 0;
880 }
881 }
882
moveStateToNewBlock(LineState & State)883 void ContinuationIndenter::moveStateToNewBlock(LineState &State) {
884 unsigned NestedBlockIndent = State.Stack.back().NestedBlockIndent;
885 // ObjC block sometimes follow special indentation rules.
886 unsigned NewIndent =
887 NestedBlockIndent + (State.NextToken->is(TT_ObjCBlockLBrace)
888 ? Style.ObjCBlockIndentWidth
889 : Style.IndentWidth);
890 State.Stack.push_back(ParenState(
891 NewIndent, /*NewIndentLevel=*/State.Stack.back().IndentLevel + 1,
892 State.Stack.back().LastSpace, /*AvoidBinPacking=*/true,
893 State.Stack.back().NoLineBreak));
894 State.Stack.back().NestedBlockIndent = NestedBlockIndent;
895 State.Stack.back().BreakBeforeParameter = true;
896 }
897
addMultilineToken(const FormatToken & Current,LineState & State)898 unsigned ContinuationIndenter::addMultilineToken(const FormatToken &Current,
899 LineState &State) {
900 // Break before further function parameters on all levels.
901 for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
902 State.Stack[i].BreakBeforeParameter = true;
903
904 unsigned ColumnsUsed = State.Column;
905 // We can only affect layout of the first and the last line, so the penalty
906 // for all other lines is constant, and we ignore it.
907 State.Column = Current.LastLineColumnWidth;
908
909 if (ColumnsUsed > getColumnLimit(State))
910 return Style.PenaltyExcessCharacter * (ColumnsUsed - getColumnLimit(State));
911 return 0;
912 }
913
breakProtrudingToken(const FormatToken & Current,LineState & State,bool DryRun)914 unsigned ContinuationIndenter::breakProtrudingToken(const FormatToken &Current,
915 LineState &State,
916 bool DryRun) {
917 // Don't break multi-line tokens other than block comments. Instead, just
918 // update the state.
919 if (Current.isNot(TT_BlockComment) && Current.IsMultiline)
920 return addMultilineToken(Current, State);
921
922 // Don't break implicit string literals or import statements.
923 if (Current.is(TT_ImplicitStringLiteral) ||
924 State.Line->Type == LT_ImportStatement)
925 return 0;
926
927 if (!Current.isStringLiteral() && !Current.is(tok::comment))
928 return 0;
929
930 std::unique_ptr<BreakableToken> Token;
931 unsigned StartColumn = State.Column - Current.ColumnWidth;
932 unsigned ColumnLimit = getColumnLimit(State);
933
934 if (Current.isStringLiteral()) {
935 // FIXME: String literal breaking is currently disabled for Java and JS, as
936 // it requires strings to be merged using "+" which we don't support.
937 if (Style.Language == FormatStyle::LK_Java ||
938 Style.Language == FormatStyle::LK_JavaScript)
939 return 0;
940
941 // Don't break string literals inside preprocessor directives (except for
942 // #define directives, as their contents are stored in separate lines and
943 // are not affected by this check).
944 // This way we avoid breaking code with line directives and unknown
945 // preprocessor directives that contain long string literals.
946 if (State.Line->Type == LT_PreprocessorDirective)
947 return 0;
948 // Exempts unterminated string literals from line breaking. The user will
949 // likely want to terminate the string before any line breaking is done.
950 if (Current.IsUnterminatedLiteral)
951 return 0;
952
953 StringRef Text = Current.TokenText;
954 StringRef Prefix;
955 StringRef Postfix;
956 bool IsNSStringLiteral = false;
957 // FIXME: Handle whitespace between '_T', '(', '"..."', and ')'.
958 // FIXME: Store Prefix and Suffix (or PrefixLength and SuffixLength to
959 // reduce the overhead) for each FormatToken, which is a string, so that we
960 // don't run multiple checks here on the hot path.
961 if (Text.startswith("\"") && Current.Previous &&
962 Current.Previous->is(tok::at)) {
963 IsNSStringLiteral = true;
964 Prefix = "@\"";
965 }
966 if ((Text.endswith(Postfix = "\"") &&
967 (IsNSStringLiteral || Text.startswith(Prefix = "\"") ||
968 Text.startswith(Prefix = "u\"") || Text.startswith(Prefix = "U\"") ||
969 Text.startswith(Prefix = "u8\"") ||
970 Text.startswith(Prefix = "L\""))) ||
971 (Text.startswith(Prefix = "_T(\"") && Text.endswith(Postfix = "\")"))) {
972 Token.reset(new BreakableStringLiteral(
973 Current, State.Line->Level, StartColumn, Prefix, Postfix,
974 State.Line->InPPDirective, Encoding, Style));
975 } else {
976 return 0;
977 }
978 } else if (Current.is(TT_BlockComment) && Current.isTrailingComment()) {
979 if (CommentPragmasRegex.match(Current.TokenText.substr(2)))
980 return 0;
981 Token.reset(new BreakableBlockComment(
982 Current, State.Line->Level, StartColumn, Current.OriginalColumn,
983 !Current.Previous, State.Line->InPPDirective, Encoding, Style));
984 } else if (Current.is(TT_LineComment) &&
985 (Current.Previous == nullptr ||
986 Current.Previous->isNot(TT_ImplicitStringLiteral))) {
987 if (CommentPragmasRegex.match(Current.TokenText.substr(2)))
988 return 0;
989 Token.reset(new BreakableLineComment(Current, State.Line->Level,
990 StartColumn, /*InPPDirective=*/false,
991 Encoding, Style));
992 // We don't insert backslashes when breaking line comments.
993 ColumnLimit = Style.ColumnLimit;
994 } else {
995 return 0;
996 }
997 if (Current.UnbreakableTailLength >= ColumnLimit)
998 return 0;
999
1000 unsigned RemainingSpace = ColumnLimit - Current.UnbreakableTailLength;
1001 bool BreakInserted = false;
1002 unsigned Penalty = 0;
1003 unsigned RemainingTokenColumns = 0;
1004 for (unsigned LineIndex = 0, EndIndex = Token->getLineCount();
1005 LineIndex != EndIndex; ++LineIndex) {
1006 if (!DryRun)
1007 Token->replaceWhitespaceBefore(LineIndex, Whitespaces);
1008 unsigned TailOffset = 0;
1009 RemainingTokenColumns =
1010 Token->getLineLengthAfterSplit(LineIndex, TailOffset, StringRef::npos);
1011 while (RemainingTokenColumns > RemainingSpace) {
1012 BreakableToken::Split Split =
1013 Token->getSplit(LineIndex, TailOffset, ColumnLimit);
1014 if (Split.first == StringRef::npos) {
1015 // The last line's penalty is handled in addNextStateToQueue().
1016 if (LineIndex < EndIndex - 1)
1017 Penalty += Style.PenaltyExcessCharacter *
1018 (RemainingTokenColumns - RemainingSpace);
1019 break;
1020 }
1021 assert(Split.first != 0);
1022 unsigned NewRemainingTokenColumns = Token->getLineLengthAfterSplit(
1023 LineIndex, TailOffset + Split.first + Split.second, StringRef::npos);
1024
1025 // We can remove extra whitespace instead of breaking the line.
1026 if (RemainingTokenColumns + 1 - Split.second <= RemainingSpace) {
1027 RemainingTokenColumns = 0;
1028 if (!DryRun)
1029 Token->replaceWhitespace(LineIndex, TailOffset, Split, Whitespaces);
1030 break;
1031 }
1032
1033 // When breaking before a tab character, it may be moved by a few columns,
1034 // but will still be expanded to the next tab stop, so we don't save any
1035 // columns.
1036 if (NewRemainingTokenColumns == RemainingTokenColumns)
1037 break;
1038
1039 assert(NewRemainingTokenColumns < RemainingTokenColumns);
1040 if (!DryRun)
1041 Token->insertBreak(LineIndex, TailOffset, Split, Whitespaces);
1042 Penalty += Current.SplitPenalty;
1043 unsigned ColumnsUsed =
1044 Token->getLineLengthAfterSplit(LineIndex, TailOffset, Split.first);
1045 if (ColumnsUsed > ColumnLimit) {
1046 Penalty += Style.PenaltyExcessCharacter * (ColumnsUsed - ColumnLimit);
1047 }
1048 TailOffset += Split.first + Split.second;
1049 RemainingTokenColumns = NewRemainingTokenColumns;
1050 BreakInserted = true;
1051 }
1052 }
1053
1054 State.Column = RemainingTokenColumns;
1055
1056 if (BreakInserted) {
1057 // If we break the token inside a parameter list, we need to break before
1058 // the next parameter on all levels, so that the next parameter is clearly
1059 // visible. Line comments already introduce a break.
1060 if (Current.isNot(TT_LineComment)) {
1061 for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
1062 State.Stack[i].BreakBeforeParameter = true;
1063 }
1064
1065 Penalty += Current.isStringLiteral() ? Style.PenaltyBreakString
1066 : Style.PenaltyBreakComment;
1067
1068 State.Stack.back().LastSpace = StartColumn;
1069 }
1070 return Penalty;
1071 }
1072
getColumnLimit(const LineState & State) const1073 unsigned ContinuationIndenter::getColumnLimit(const LineState &State) const {
1074 // In preprocessor directives reserve two chars for trailing " \"
1075 return Style.ColumnLimit - (State.Line->InPPDirective ? 2 : 0);
1076 }
1077
nextIsMultilineString(const LineState & State)1078 bool ContinuationIndenter::nextIsMultilineString(const LineState &State) {
1079 const FormatToken &Current = *State.NextToken;
1080 if (!Current.isStringLiteral() || Current.is(TT_ImplicitStringLiteral))
1081 return false;
1082 // We never consider raw string literals "multiline" for the purpose of
1083 // AlwaysBreakBeforeMultilineStrings implementation as they are special-cased
1084 // (see TokenAnnotator::mustBreakBefore().
1085 if (Current.TokenText.startswith("R\""))
1086 return false;
1087 if (Current.IsMultiline)
1088 return true;
1089 if (Current.getNextNonComment() &&
1090 Current.getNextNonComment()->isStringLiteral())
1091 return true; // Implicit concatenation.
1092 if (Style.ColumnLimit != 0 &&
1093 State.Column + Current.ColumnWidth + Current.UnbreakableTailLength >
1094 Style.ColumnLimit)
1095 return true; // String will be split.
1096 return false;
1097 }
1098
1099 } // namespace format
1100 } // namespace clang
1101