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
26namespace clang {
27namespace format {
28
29// Returns the length of everything up to the first possible line break after
30// the ), ], } or > matching \c Tok.
31static 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
41static unsigned getLengthToNextOperator(const FormatToken &Tok) {
42  if (!Tok.NextOperator)
43    return 0;
44  return Tok.NextOperator->TotalLength - Tok.TotalLength;
45}
46
47// Returns \c true if \c Tok is the "." or "->" of a call and starts the next
48// segment of a builder type call.
49static bool startsSegmentOfBuilderTypeCall(const FormatToken &Tok) {
50  return Tok.isMemberAccess() && Tok.Previous && Tok.Previous->closesScope();
51}
52
53// Returns \c true if \c Current starts a new parameter.
54static bool startsNextParameter(const FormatToken &Current,
55                                const FormatStyle &Style) {
56  const FormatToken &Previous = *Current.Previous;
57  if (Current.is(TT_CtorInitializerComma) &&
58      Style.BreakConstructorInitializersBeforeComma)
59    return true;
60  return Previous.is(tok::comma) && !Current.isTrailingComment() &&
61         (Previous.isNot(TT_CtorInitializerComma) ||
62          !Style.BreakConstructorInitializersBeforeComma);
63}
64
65ContinuationIndenter::ContinuationIndenter(const FormatStyle &Style,
66                                           const AdditionalKeywords &Keywords,
67                                           const SourceManager &SourceMgr,
68                                           WhitespaceManager &Whitespaces,
69                                           encoding::Encoding Encoding,
70                                           bool BinPackInconclusiveFunctions)
71    : Style(Style), Keywords(Keywords), SourceMgr(SourceMgr),
72      Whitespaces(Whitespaces), Encoding(Encoding),
73      BinPackInconclusiveFunctions(BinPackInconclusiveFunctions),
74      CommentPragmasRegex(Style.CommentPragmas) {}
75
76LineState ContinuationIndenter::getInitialState(unsigned FirstIndent,
77                                                const AnnotatedLine *Line,
78                                                bool DryRun) {
79  LineState State;
80  State.FirstIndent = FirstIndent;
81  State.Column = FirstIndent;
82  State.Line = Line;
83  State.NextToken = Line->First;
84  State.Stack.push_back(ParenState(FirstIndent, Line->Level, FirstIndent,
85                                   /*AvoidBinPacking=*/false,
86                                   /*NoLineBreak=*/false));
87  State.LineContainsContinuedForLoopSection = false;
88  State.StartOfStringLiteral = 0;
89  State.StartOfLineLevel = 0;
90  State.LowestLevelOnLine = 0;
91  State.IgnoreStackForComparison = false;
92
93  // The first token has already been indented and thus consumed.
94  moveStateToNextToken(State, DryRun, /*Newline=*/false);
95  return State;
96}
97
98bool ContinuationIndenter::canBreak(const LineState &State) {
99  const FormatToken &Current = *State.NextToken;
100  const FormatToken &Previous = *Current.Previous;
101  assert(&Previous == Current.Previous);
102  if (!Current.CanBreakBefore &&
103      !(State.Stack.back().BreakBeforeClosingBrace &&
104        Current.closesBlockOrBlockTypeList(Style)))
105    return false;
106  // The opening "{" of a braced list has to be on the same line as the first
107  // element if it is nested in another braced init list or function call.
108  if (!Current.MustBreakBefore && Previous.is(tok::l_brace) &&
109      Previous.isNot(TT_DictLiteral) && Previous.BlockKind == BK_BracedInit &&
110      Previous.Previous &&
111      Previous.Previous->isOneOf(tok::l_brace, tok::l_paren, tok::comma))
112    return false;
113  // This prevents breaks like:
114  //   ...
115  //   SomeParameter, OtherParameter).DoSomething(
116  //   ...
117  // As they hide "DoSomething" and are generally bad for readability.
118  if (Previous.opensScope() && Previous.isNot(tok::l_brace) &&
119      State.LowestLevelOnLine < State.StartOfLineLevel &&
120      State.LowestLevelOnLine < Current.NestingLevel)
121    return false;
122  if (Current.isMemberAccess() && State.Stack.back().ContainsUnwrappedBuilder)
123    return false;
124
125  // Don't create a 'hanging' indent if there are multiple blocks in a single
126  // statement.
127  if (Previous.is(tok::l_brace) && State.Stack.size() > 1 &&
128      State.Stack[State.Stack.size() - 2].NestedBlockInlined &&
129      State.Stack[State.Stack.size() - 2].HasMultipleNestedBlocks)
130    return false;
131
132  // Don't break after very short return types (e.g. "void") as that is often
133  // unexpected.
134  if (Current.is(TT_FunctionDeclarationName) && State.Column < 6) {
135    if (Style.AlwaysBreakAfterReturnType == FormatStyle::RTBS_None)
136      return false;
137  }
138
139  return !State.Stack.back().NoLineBreak;
140}
141
142bool ContinuationIndenter::mustBreak(const LineState &State) {
143  const FormatToken &Current = *State.NextToken;
144  const FormatToken &Previous = *Current.Previous;
145  if (Current.MustBreakBefore || Current.is(TT_InlineASMColon))
146    return true;
147  if (State.Stack.back().BreakBeforeClosingBrace &&
148      Current.closesBlockOrBlockTypeList(Style))
149    return true;
150  if (Previous.is(tok::semi) && State.LineContainsContinuedForLoopSection)
151    return true;
152  if ((startsNextParameter(Current, Style) || Previous.is(tok::semi) ||
153       (Previous.is(TT_TemplateCloser) && Current.is(TT_StartOfName) &&
154        Style.Language == FormatStyle::LK_Cpp &&
155        // FIXME: This is a temporary workaround for the case where clang-format
156        // sets BreakBeforeParameter to avoid bin packing and this creates a
157        // completely unnecessary line break after a template type that isn't
158        // line-wrapped.
159        (Previous.NestingLevel == 1 || Style.BinPackParameters)) ||
160       (Style.BreakBeforeTernaryOperators && Current.is(TT_ConditionalExpr) &&
161        Previous.isNot(tok::question)) ||
162       (!Style.BreakBeforeTernaryOperators &&
163        Previous.is(TT_ConditionalExpr))) &&
164      State.Stack.back().BreakBeforeParameter && !Current.isTrailingComment() &&
165      !Current.isOneOf(tok::r_paren, tok::r_brace))
166    return true;
167  if (((Previous.is(TT_DictLiteral) && Previous.is(tok::l_brace)) ||
168       (Previous.is(TT_ArrayInitializerLSquare) &&
169        Previous.ParameterCount > 1)) &&
170      Style.ColumnLimit > 0 &&
171      getLengthToMatchingParen(Previous) + State.Column - 1 >
172          getColumnLimit(State))
173    return true;
174  if (Current.is(TT_CtorInitializerColon) &&
175      (State.Column + State.Line->Last->TotalLength - Current.TotalLength + 2 >
176           getColumnLimit(State) ||
177       State.Stack.back().BreakBeforeParameter) &&
178      ((Style.AllowShortFunctionsOnASingleLine != FormatStyle::SFS_All) ||
179       Style.BreakConstructorInitializersBeforeComma || Style.ColumnLimit != 0))
180    return true;
181  if (Current.is(TT_SelectorName) && State.Stack.back().ObjCSelectorNameFound &&
182      State.Stack.back().BreakBeforeParameter)
183    return true;
184
185  unsigned NewLineColumn = getNewLineColumn(State);
186  if (Current.isMemberAccess() && Style.ColumnLimit != 0 &&
187      State.Column + getLengthToNextOperator(Current) > Style.ColumnLimit &&
188      (State.Column > NewLineColumn ||
189       Current.NestingLevel < State.StartOfLineLevel))
190    return true;
191
192  if (State.Column <= NewLineColumn)
193    return false;
194
195  if (Style.AlwaysBreakBeforeMultilineStrings &&
196      (NewLineColumn == State.FirstIndent + Style.ContinuationIndentWidth ||
197       Previous.is(tok::comma) || Current.NestingLevel < 2) &&
198      !Previous.isOneOf(tok::kw_return, tok::lessless, tok::at) &&
199      !Previous.isOneOf(TT_InlineASMColon, TT_ConditionalExpr) &&
200      nextIsMultilineString(State))
201    return true;
202
203  // Using CanBreakBefore here and below takes care of the decision whether the
204  // current style uses wrapping before or after operators for the given
205  // operator.
206  if (Previous.is(TT_BinaryOperator) && Current.CanBreakBefore) {
207    // If we need to break somewhere inside the LHS of a binary expression, we
208    // should also break after the operator. Otherwise, the formatting would
209    // hide the operator precedence, e.g. in:
210    //   if (aaaaaaaaaaaaaa ==
211    //           bbbbbbbbbbbbbb && c) {..
212    // For comparisons, we only apply this rule, if the LHS is a binary
213    // expression itself as otherwise, the line breaks seem superfluous.
214    // We need special cases for ">>" which we have split into two ">" while
215    // lexing in order to make template parsing easier.
216    bool IsComparison = (Previous.getPrecedence() == prec::Relational ||
217                         Previous.getPrecedence() == prec::Equality) &&
218                        Previous.Previous &&
219                        Previous.Previous->isNot(TT_BinaryOperator); // For >>.
220    bool LHSIsBinaryExpr =
221        Previous.Previous && Previous.Previous->EndsBinaryExpression;
222    if ((!IsComparison || LHSIsBinaryExpr) && !Current.isTrailingComment() &&
223        Previous.getPrecedence() != prec::Assignment &&
224        State.Stack.back().BreakBeforeParameter)
225      return true;
226  } else if (Current.is(TT_BinaryOperator) && Current.CanBreakBefore &&
227             State.Stack.back().BreakBeforeParameter) {
228    return true;
229  }
230
231  // Same as above, but for the first "<<" operator.
232  if (Current.is(tok::lessless) && Current.isNot(TT_OverloadedOperator) &&
233      State.Stack.back().BreakBeforeParameter &&
234      State.Stack.back().FirstLessLess == 0)
235    return true;
236
237  if (Current.NestingLevel == 0 && !Current.isTrailingComment()) {
238    // Always break after "template <...>" and leading annotations. This is only
239    // for cases where the entire line does not fit on a single line as a
240    // different LineFormatter would be used otherwise.
241    if (Previous.ClosesTemplateDeclaration)
242      return true;
243    if (Previous.is(TT_FunctionAnnotationRParen))
244      return true;
245    if (Previous.is(TT_LeadingJavaAnnotation) && Current.isNot(tok::l_paren) &&
246        Current.isNot(TT_LeadingJavaAnnotation))
247      return true;
248  }
249
250  // If the return type spans multiple lines, wrap before the function name.
251  if ((Current.is(TT_FunctionDeclarationName) ||
252       (Current.is(tok::kw_operator) && !Previous.is(tok::coloncolon))) &&
253      !Previous.is(tok::kw_template) && State.Stack.back().BreakBeforeParameter)
254    return true;
255
256  if (startsSegmentOfBuilderTypeCall(Current) &&
257      (State.Stack.back().CallContinuation != 0 ||
258       State.Stack.back().BreakBeforeParameter))
259    return true;
260
261  // The following could be precomputed as they do not depend on the state.
262  // However, as they should take effect only if the UnwrappedLine does not fit
263  // into the ColumnLimit, they are checked here in the ContinuationIndenter.
264  if (Style.ColumnLimit != 0 && Previous.BlockKind == BK_Block &&
265      Previous.is(tok::l_brace) && !Current.isOneOf(tok::r_brace, tok::comment))
266    return true;
267
268  if (Current.is(tok::lessless) &&
269      ((Previous.is(tok::identifier) && Previous.TokenText == "endl") ||
270       (Previous.Tok.isLiteral() && (Previous.TokenText.endswith("\\n\"") ||
271                                     Previous.TokenText == "\'\\n\'"))))
272    return true;
273
274  return false;
275}
276
277unsigned ContinuationIndenter::addTokenToState(LineState &State, bool Newline,
278                                               bool DryRun,
279                                               unsigned ExtraSpaces) {
280  const FormatToken &Current = *State.NextToken;
281
282  assert(!State.Stack.empty());
283  if ((Current.is(TT_ImplicitStringLiteral) &&
284       (Current.Previous->Tok.getIdentifierInfo() == nullptr ||
285        Current.Previous->Tok.getIdentifierInfo()->getPPKeywordID() ==
286            tok::pp_not_keyword))) {
287    unsigned EndColumn =
288        SourceMgr.getSpellingColumnNumber(Current.WhitespaceRange.getEnd());
289    if (Current.LastNewlineOffset != 0) {
290      // If there is a newline within this token, the final column will solely
291      // determined by the current end column.
292      State.Column = EndColumn;
293    } else {
294      unsigned StartColumn =
295          SourceMgr.getSpellingColumnNumber(Current.WhitespaceRange.getBegin());
296      assert(EndColumn >= StartColumn);
297      State.Column += EndColumn - StartColumn;
298    }
299    moveStateToNextToken(State, DryRun, /*Newline=*/false);
300    return 0;
301  }
302
303  unsigned Penalty = 0;
304  if (Newline)
305    Penalty = addTokenOnNewLine(State, DryRun);
306  else
307    addTokenOnCurrentLine(State, DryRun, ExtraSpaces);
308
309  return moveStateToNextToken(State, DryRun, Newline) + Penalty;
310}
311
312void ContinuationIndenter::addTokenOnCurrentLine(LineState &State, bool DryRun,
313                                                 unsigned ExtraSpaces) {
314  FormatToken &Current = *State.NextToken;
315  const FormatToken &Previous = *State.NextToken->Previous;
316  if (Current.is(tok::equal) &&
317      (State.Line->First->is(tok::kw_for) || Current.NestingLevel == 0) &&
318      State.Stack.back().VariablePos == 0) {
319    State.Stack.back().VariablePos = State.Column;
320    // Move over * and & if they are bound to the variable name.
321    const FormatToken *Tok = &Previous;
322    while (Tok && State.Stack.back().VariablePos >= Tok->ColumnWidth) {
323      State.Stack.back().VariablePos -= Tok->ColumnWidth;
324      if (Tok->SpacesRequiredBefore != 0)
325        break;
326      Tok = Tok->Previous;
327    }
328    if (Previous.PartOfMultiVariableDeclStmt)
329      State.Stack.back().LastSpace = State.Stack.back().VariablePos;
330  }
331
332  unsigned Spaces = Current.SpacesRequiredBefore + ExtraSpaces;
333
334  if (!DryRun)
335    Whitespaces.replaceWhitespace(Current, /*Newlines=*/0, /*IndentLevel=*/0,
336                                  Spaces, State.Column + Spaces);
337
338  if (Current.is(TT_SelectorName) &&
339      !State.Stack.back().ObjCSelectorNameFound) {
340    unsigned MinIndent =
341        std::max(State.FirstIndent + Style.ContinuationIndentWidth,
342                 State.Stack.back().Indent);
343    unsigned FirstColonPos = State.Column + Spaces + Current.ColumnWidth;
344    if (Current.LongestObjCSelectorName == 0)
345      State.Stack.back().AlignColons = false;
346    else if (MinIndent + Current.LongestObjCSelectorName > FirstColonPos)
347      State.Stack.back().ColonPos = MinIndent + Current.LongestObjCSelectorName;
348    else
349      State.Stack.back().ColonPos = FirstColonPos;
350  }
351
352  // In "AlwaysBreak" mode, enforce wrapping directly after the parenthesis by
353  // disallowing any further line breaks if there is no line break after the
354  // opening parenthesis. Don't break if it doesn't conserve columns.
355  if (Style.AlignAfterOpenBracket == FormatStyle::BAS_AlwaysBreak &&
356      Previous.isOneOf(tok::l_paren, TT_TemplateOpener, tok::l_square) &&
357      State.Column > getNewLineColumn(State) &&
358      (!Previous.Previous ||
359       !Previous.Previous->isOneOf(tok::kw_for, tok::kw_while,
360                                   tok::kw_switch)) &&
361      // Don't do this for simple (no expressions) one-argument function calls
362      // as that feels like needlessly wasting whitespace, e.g.:
363      //
364      //   caaaaaaaaaaaall(
365      //       caaaaaaaaaaaall(
366      //           caaaaaaaaaaaall(
367      //               caaaaaaaaaaaaaaaaaaaaaaall(aaaaaaaaaaaaaa, aaaaaaaaa))));
368      Current.FakeLParens.size() > 0 &&
369      Current.FakeLParens.back() > prec::Unknown)
370    State.Stack.back().NoLineBreak = true;
371
372  if (Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign &&
373      Previous.opensScope() && Previous.isNot(TT_ObjCMethodExpr) &&
374      (Current.isNot(TT_LineComment) || Previous.BlockKind == BK_BracedInit))
375    State.Stack.back().Indent = State.Column + Spaces;
376  if (State.Stack.back().AvoidBinPacking && startsNextParameter(Current, Style))
377    State.Stack.back().NoLineBreak = true;
378  if (startsSegmentOfBuilderTypeCall(Current) &&
379      State.Column > getNewLineColumn(State))
380    State.Stack.back().ContainsUnwrappedBuilder = true;
381
382  if (Current.is(TT_LambdaArrow) && Style.Language == FormatStyle::LK_Java)
383    State.Stack.back().NoLineBreak = true;
384  if (Current.isMemberAccess() && Previous.is(tok::r_paren) &&
385      (Previous.MatchingParen &&
386       (Previous.TotalLength - Previous.MatchingParen->TotalLength > 10))) {
387    // If there is a function call with long parameters, break before trailing
388    // calls. This prevents things like:
389    //   EXPECT_CALL(SomeLongParameter).Times(
390    //       2);
391    // We don't want to do this for short parameters as they can just be
392    // indexes.
393    State.Stack.back().NoLineBreak = true;
394  }
395
396  State.Column += Spaces;
397  if (Current.isNot(tok::comment) && Previous.is(tok::l_paren) &&
398      Previous.Previous &&
399      Previous.Previous->isOneOf(tok::kw_if, tok::kw_for)) {
400    // Treat the condition inside an if as if it was a second function
401    // parameter, i.e. let nested calls have a continuation indent.
402    State.Stack.back().LastSpace = State.Column;
403    State.Stack.back().NestedBlockIndent = State.Column;
404  } else if (!Current.isOneOf(tok::comment, tok::caret) &&
405             ((Previous.is(tok::comma) &&
406               !Previous.is(TT_OverloadedOperator)) ||
407              (Previous.is(tok::colon) && Previous.is(TT_ObjCMethodExpr)))) {
408    State.Stack.back().LastSpace = State.Column;
409  } else if ((Previous.isOneOf(TT_BinaryOperator, TT_ConditionalExpr,
410                               TT_CtorInitializerColon)) &&
411             ((Previous.getPrecedence() != prec::Assignment &&
412               (Previous.isNot(tok::lessless) || Previous.OperatorIndex != 0 ||
413                Previous.NextOperator)) ||
414              Current.StartsBinaryExpression)) {
415    // Indent relative to the RHS of the expression unless this is a simple
416    // assignment without binary expression on the RHS. Also indent relative to
417    // unary operators and the colons of constructor initializers.
418    State.Stack.back().LastSpace = State.Column;
419  } else if (Previous.is(TT_InheritanceColon)) {
420    State.Stack.back().Indent = State.Column;
421    State.Stack.back().LastSpace = State.Column;
422  } else if (Previous.opensScope()) {
423    // If a function has a trailing call, indent all parameters from the
424    // opening parenthesis. This avoids confusing indents like:
425    //   OuterFunction(InnerFunctionCall( // break
426    //       ParameterToInnerFunction))   // break
427    //       .SecondInnerFunctionCall();
428    bool HasTrailingCall = false;
429    if (Previous.MatchingParen) {
430      const FormatToken *Next = Previous.MatchingParen->getNextNonComment();
431      HasTrailingCall = Next && Next->isMemberAccess();
432    }
433    if (HasTrailingCall && State.Stack.size() > 1 &&
434        State.Stack[State.Stack.size() - 2].CallContinuation == 0)
435      State.Stack.back().LastSpace = State.Column;
436  }
437}
438
439unsigned ContinuationIndenter::addTokenOnNewLine(LineState &State,
440                                                 bool DryRun) {
441  FormatToken &Current = *State.NextToken;
442  const FormatToken &Previous = *State.NextToken->Previous;
443
444  // Extra penalty that needs to be added because of the way certain line
445  // breaks are chosen.
446  unsigned Penalty = 0;
447
448  const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
449  const FormatToken *NextNonComment = Previous.getNextNonComment();
450  if (!NextNonComment)
451    NextNonComment = &Current;
452  // The first line break on any NestingLevel causes an extra penalty in order
453  // prefer similar line breaks.
454  if (!State.Stack.back().ContainsLineBreak)
455    Penalty += 15;
456  State.Stack.back().ContainsLineBreak = true;
457
458  Penalty += State.NextToken->SplitPenalty;
459
460  // Breaking before the first "<<" is generally not desirable if the LHS is
461  // short. Also always add the penalty if the LHS is split over mutliple lines
462  // to avoid unnecessary line breaks that just work around this penalty.
463  if (NextNonComment->is(tok::lessless) &&
464      State.Stack.back().FirstLessLess == 0 &&
465      (State.Column <= Style.ColumnLimit / 3 ||
466       State.Stack.back().BreakBeforeParameter))
467    Penalty += Style.PenaltyBreakFirstLessLess;
468
469  State.Column = getNewLineColumn(State);
470
471  // Indent nested blocks relative to this column, unless in a very specific
472  // JavaScript special case where:
473  //
474  //   var loooooong_name =
475  //       function() {
476  //     // code
477  //   }
478  //
479  // is common and should be formatted like a free-standing function. The same
480  // goes for wrapping before the lambda return type arrow.
481  if (!Current.is(TT_LambdaArrow) &&
482      (Style.Language != FormatStyle::LK_JavaScript ||
483       Current.NestingLevel != 0 || !PreviousNonComment ||
484       !PreviousNonComment->is(tok::equal) ||
485       !Current.isOneOf(Keywords.kw_async, Keywords.kw_function)))
486    State.Stack.back().NestedBlockIndent = State.Column;
487
488  if (NextNonComment->isMemberAccess()) {
489    if (State.Stack.back().CallContinuation == 0)
490      State.Stack.back().CallContinuation = State.Column;
491  } else if (NextNonComment->is(TT_SelectorName)) {
492    if (!State.Stack.back().ObjCSelectorNameFound) {
493      if (NextNonComment->LongestObjCSelectorName == 0) {
494        State.Stack.back().AlignColons = false;
495      } else {
496        State.Stack.back().ColonPos =
497            (Style.IndentWrappedFunctionNames
498                 ? std::max(State.Stack.back().Indent,
499                            State.FirstIndent + Style.ContinuationIndentWidth)
500                 : State.Stack.back().Indent) +
501            NextNonComment->LongestObjCSelectorName;
502      }
503    } else if (State.Stack.back().AlignColons &&
504               State.Stack.back().ColonPos <= NextNonComment->ColumnWidth) {
505      State.Stack.back().ColonPos = State.Column + NextNonComment->ColumnWidth;
506    }
507  } else if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
508             PreviousNonComment->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral)) {
509    // FIXME: This is hacky, find a better way. The problem is that in an ObjC
510    // method expression, the block should be aligned to the line starting it,
511    // e.g.:
512    //   [aaaaaaaaaaaaaaa aaaaaaaaa: \\ break for some reason
513    //                        ^(int *i) {
514    //                            // ...
515    //                        }];
516    // Thus, we set LastSpace of the next higher NestingLevel, to which we move
517    // when we consume all of the "}"'s FakeRParens at the "{".
518    if (State.Stack.size() > 1)
519      State.Stack[State.Stack.size() - 2].LastSpace =
520          std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) +
521          Style.ContinuationIndentWidth;
522  }
523
524  if ((Previous.isOneOf(tok::comma, tok::semi) &&
525       !State.Stack.back().AvoidBinPacking) ||
526      Previous.is(TT_BinaryOperator))
527    State.Stack.back().BreakBeforeParameter = false;
528  if (Previous.isOneOf(TT_TemplateCloser, TT_JavaAnnotation) &&
529      Current.NestingLevel == 0)
530    State.Stack.back().BreakBeforeParameter = false;
531  if (NextNonComment->is(tok::question) ||
532      (PreviousNonComment && PreviousNonComment->is(tok::question)))
533    State.Stack.back().BreakBeforeParameter = true;
534  if (Current.is(TT_BinaryOperator) && Current.CanBreakBefore)
535    State.Stack.back().BreakBeforeParameter = false;
536
537  if (!DryRun) {
538    unsigned Newlines = std::max(
539        1u, std::min(Current.NewlinesBefore, Style.MaxEmptyLinesToKeep + 1));
540    Whitespaces.replaceWhitespace(Current, Newlines,
541                                  State.Stack.back().IndentLevel, State.Column,
542                                  State.Column, State.Line->InPPDirective);
543  }
544
545  if (!Current.isTrailingComment())
546    State.Stack.back().LastSpace = State.Column;
547  if (Current.is(tok::lessless))
548    // If we are breaking before a "<<", we always want to indent relative to
549    // RHS. This is necessary only for "<<", as we special-case it and don't
550    // always indent relative to the RHS.
551    State.Stack.back().LastSpace += 3; // 3 -> width of "<< ".
552
553  State.StartOfLineLevel = Current.NestingLevel;
554  State.LowestLevelOnLine = Current.NestingLevel;
555
556  // Any break on this level means that the parent level has been broken
557  // and we need to avoid bin packing there.
558  bool NestedBlockSpecialCase =
559      Style.Language != FormatStyle::LK_Cpp &&
560      Current.is(tok::r_brace) && State.Stack.size() > 1 &&
561      State.Stack[State.Stack.size() - 2].NestedBlockInlined;
562  if (!NestedBlockSpecialCase)
563    for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i)
564      State.Stack[i].BreakBeforeParameter = true;
565
566  if (PreviousNonComment &&
567      !PreviousNonComment->isOneOf(tok::comma, tok::semi) &&
568      (PreviousNonComment->isNot(TT_TemplateCloser) ||
569       Current.NestingLevel != 0) &&
570      !PreviousNonComment->isOneOf(
571          TT_BinaryOperator, TT_FunctionAnnotationRParen, TT_JavaAnnotation,
572          TT_LeadingJavaAnnotation) &&
573      Current.isNot(TT_BinaryOperator) && !PreviousNonComment->opensScope())
574    State.Stack.back().BreakBeforeParameter = true;
575
576  // If we break after { or the [ of an array initializer, we should also break
577  // before the corresponding } or ].
578  if (PreviousNonComment &&
579      (PreviousNonComment->isOneOf(tok::l_brace, TT_ArrayInitializerLSquare)))
580    State.Stack.back().BreakBeforeClosingBrace = true;
581
582  if (State.Stack.back().AvoidBinPacking) {
583    // If we are breaking after '(', '{', '<', this is not bin packing
584    // unless AllowAllParametersOfDeclarationOnNextLine is false or this is a
585    // dict/object literal.
586    if (!Previous.isOneOf(tok::l_paren, tok::l_brace, TT_BinaryOperator) ||
587        (!Style.AllowAllParametersOfDeclarationOnNextLine &&
588         State.Line->MustBeDeclaration) ||
589        Previous.is(TT_DictLiteral))
590      State.Stack.back().BreakBeforeParameter = true;
591  }
592
593  return Penalty;
594}
595
596unsigned ContinuationIndenter::getNewLineColumn(const LineState &State) {
597  if (!State.NextToken || !State.NextToken->Previous)
598    return 0;
599  FormatToken &Current = *State.NextToken;
600  const FormatToken &Previous = *Current.Previous;
601  // If we are continuing an expression, we want to use the continuation indent.
602  unsigned ContinuationIndent =
603      std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) +
604      Style.ContinuationIndentWidth;
605  const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
606  const FormatToken *NextNonComment = Previous.getNextNonComment();
607  if (!NextNonComment)
608    NextNonComment = &Current;
609
610  // Java specific bits.
611  if (Style.Language == FormatStyle::LK_Java &&
612      Current.isOneOf(Keywords.kw_implements, Keywords.kw_extends))
613    return std::max(State.Stack.back().LastSpace,
614                    State.Stack.back().Indent + Style.ContinuationIndentWidth);
615
616  if (NextNonComment->is(tok::l_brace) && NextNonComment->BlockKind == BK_Block)
617    return Current.NestingLevel == 0 ? State.FirstIndent
618                                     : State.Stack.back().Indent;
619  if (Current.isOneOf(tok::r_brace, tok::r_square) && State.Stack.size() > 1) {
620    if (Current.closesBlockOrBlockTypeList(Style))
621      return State.Stack[State.Stack.size() - 2].NestedBlockIndent;
622    if (Current.MatchingParen &&
623        Current.MatchingParen->BlockKind == BK_BracedInit)
624      return State.Stack[State.Stack.size() - 2].LastSpace;
625    return State.FirstIndent;
626  }
627  if (Current.is(tok::identifier) && Current.Next &&
628      Current.Next->is(TT_DictLiteral))
629    return State.Stack.back().Indent;
630  if (NextNonComment->isStringLiteral() && State.StartOfStringLiteral != 0)
631    return State.StartOfStringLiteral;
632  if (NextNonComment->is(TT_ObjCStringLiteral) &&
633      State.StartOfStringLiteral != 0)
634    return State.StartOfStringLiteral - 1;
635  if (NextNonComment->is(tok::lessless) &&
636      State.Stack.back().FirstLessLess != 0)
637    return State.Stack.back().FirstLessLess;
638  if (NextNonComment->isMemberAccess()) {
639    if (State.Stack.back().CallContinuation == 0)
640      return ContinuationIndent;
641    return State.Stack.back().CallContinuation;
642  }
643  if (State.Stack.back().QuestionColumn != 0 &&
644      ((NextNonComment->is(tok::colon) &&
645        NextNonComment->is(TT_ConditionalExpr)) ||
646       Previous.is(TT_ConditionalExpr)))
647    return State.Stack.back().QuestionColumn;
648  if (Previous.is(tok::comma) && State.Stack.back().VariablePos != 0)
649    return State.Stack.back().VariablePos;
650  if ((PreviousNonComment &&
651       (PreviousNonComment->ClosesTemplateDeclaration ||
652        PreviousNonComment->isOneOf(
653            TT_AttributeParen, TT_FunctionAnnotationRParen, TT_JavaAnnotation,
654            TT_LeadingJavaAnnotation))) ||
655      (!Style.IndentWrappedFunctionNames &&
656       NextNonComment->isOneOf(tok::kw_operator, TT_FunctionDeclarationName)))
657    return std::max(State.Stack.back().LastSpace, State.Stack.back().Indent);
658  if (NextNonComment->is(TT_SelectorName)) {
659    if (!State.Stack.back().ObjCSelectorNameFound) {
660      if (NextNonComment->LongestObjCSelectorName == 0)
661        return State.Stack.back().Indent;
662      return (Style.IndentWrappedFunctionNames
663                  ? std::max(State.Stack.back().Indent,
664                             State.FirstIndent + Style.ContinuationIndentWidth)
665                  : State.Stack.back().Indent) +
666             NextNonComment->LongestObjCSelectorName -
667             NextNonComment->ColumnWidth;
668    }
669    if (!State.Stack.back().AlignColons)
670      return State.Stack.back().Indent;
671    if (State.Stack.back().ColonPos > NextNonComment->ColumnWidth)
672      return State.Stack.back().ColonPos - NextNonComment->ColumnWidth;
673    return State.Stack.back().Indent;
674  }
675  if (NextNonComment->is(TT_ArraySubscriptLSquare)) {
676    if (State.Stack.back().StartOfArraySubscripts != 0)
677      return State.Stack.back().StartOfArraySubscripts;
678    return ContinuationIndent;
679  }
680
681  // This ensure that we correctly format ObjC methods calls without inputs,
682  // i.e. where the last element isn't selector like: [callee method];
683  if (NextNonComment->is(tok::identifier) && NextNonComment->FakeRParens == 0 &&
684      NextNonComment->Next && NextNonComment->Next->is(TT_ObjCMethodExpr))
685    return State.Stack.back().Indent;
686
687  if (NextNonComment->isOneOf(TT_StartOfName, TT_PointerOrReference) ||
688      Previous.isOneOf(tok::coloncolon, tok::equal, TT_JsTypeColon))
689    return ContinuationIndent;
690  if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
691      PreviousNonComment->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral))
692    return ContinuationIndent;
693  if (NextNonComment->is(TT_CtorInitializerColon))
694    return State.FirstIndent + Style.ConstructorInitializerIndentWidth;
695  if (NextNonComment->is(TT_CtorInitializerComma))
696    return State.Stack.back().Indent;
697  if (Previous.is(tok::r_paren) && !Current.isBinaryOperator() &&
698      !Current.isOneOf(tok::colon, tok::comment))
699    return ContinuationIndent;
700  if (State.Stack.back().Indent == State.FirstIndent && PreviousNonComment &&
701      PreviousNonComment->isNot(tok::r_brace))
702    // Ensure that we fall back to the continuation indent width instead of
703    // just flushing continuations left.
704    return State.Stack.back().Indent + Style.ContinuationIndentWidth;
705  return State.Stack.back().Indent;
706}
707
708unsigned ContinuationIndenter::moveStateToNextToken(LineState &State,
709                                                    bool DryRun, bool Newline) {
710  assert(State.Stack.size());
711  const FormatToken &Current = *State.NextToken;
712
713  if (Current.is(TT_InheritanceColon))
714    State.Stack.back().AvoidBinPacking = true;
715  if (Current.is(tok::lessless) && Current.isNot(TT_OverloadedOperator)) {
716    if (State.Stack.back().FirstLessLess == 0)
717      State.Stack.back().FirstLessLess = State.Column;
718    else
719      State.Stack.back().LastOperatorWrapped = Newline;
720  }
721  if ((Current.is(TT_BinaryOperator) && Current.isNot(tok::lessless)) ||
722      Current.is(TT_ConditionalExpr))
723    State.Stack.back().LastOperatorWrapped = Newline;
724  if (Current.is(TT_ArraySubscriptLSquare) &&
725      State.Stack.back().StartOfArraySubscripts == 0)
726    State.Stack.back().StartOfArraySubscripts = State.Column;
727  if (Style.BreakBeforeTernaryOperators && Current.is(tok::question))
728    State.Stack.back().QuestionColumn = State.Column;
729  if (!Style.BreakBeforeTernaryOperators && Current.isNot(tok::colon)) {
730    const FormatToken *Previous = Current.Previous;
731    while (Previous && Previous->isTrailingComment())
732      Previous = Previous->Previous;
733    if (Previous && Previous->is(tok::question))
734      State.Stack.back().QuestionColumn = State.Column;
735  }
736  if (!Current.opensScope() && !Current.closesScope())
737    State.LowestLevelOnLine =
738        std::min(State.LowestLevelOnLine, Current.NestingLevel);
739  if (Current.isMemberAccess())
740    State.Stack.back().StartOfFunctionCall =
741        !Current.NextOperator ? 0 : State.Column;
742  if (Current.is(TT_SelectorName)) {
743    State.Stack.back().ObjCSelectorNameFound = true;
744    if (Style.IndentWrappedFunctionNames) {
745      State.Stack.back().Indent =
746          State.FirstIndent + Style.ContinuationIndentWidth;
747    }
748  }
749  if (Current.is(TT_CtorInitializerColon)) {
750    // Indent 2 from the column, so:
751    // SomeClass::SomeClass()
752    //     : First(...), ...
753    //       Next(...)
754    //       ^ line up here.
755    State.Stack.back().Indent =
756        State.Column + (Style.BreakConstructorInitializersBeforeComma ? 0 : 2);
757    State.Stack.back().NestedBlockIndent = State.Stack.back().Indent;
758    if (Style.ConstructorInitializerAllOnOneLineOrOnePerLine)
759      State.Stack.back().AvoidBinPacking = true;
760    State.Stack.back().BreakBeforeParameter = false;
761  }
762  if (Current.isOneOf(TT_BinaryOperator, TT_ConditionalExpr) && Newline)
763    State.Stack.back().NestedBlockIndent =
764        State.Column + Current.ColumnWidth + 1;
765
766  // Insert scopes created by fake parenthesis.
767  const FormatToken *Previous = Current.getPreviousNonComment();
768
769  // Add special behavior to support a format commonly used for JavaScript
770  // closures:
771  //   SomeFunction(function() {
772  //     foo();
773  //     bar();
774  //   }, a, b, c);
775  if (Current.isNot(tok::comment) && Previous &&
776      Previous->isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) &&
777      !Previous->is(TT_DictLiteral) && State.Stack.size() > 1) {
778    if (State.Stack[State.Stack.size() - 2].NestedBlockInlined && Newline)
779      for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i)
780        State.Stack[i].NoLineBreak = true;
781    State.Stack[State.Stack.size() - 2].NestedBlockInlined = false;
782  }
783  if (Previous && (Previous->isOneOf(tok::l_paren, tok::comma, tok::colon) ||
784                   Previous->isOneOf(TT_BinaryOperator, TT_ConditionalExpr)) &&
785      !Previous->isOneOf(TT_DictLiteral, TT_ObjCMethodExpr)) {
786    State.Stack.back().NestedBlockInlined =
787        !Newline &&
788        (Previous->isNot(tok::l_paren) || Previous->ParameterCount > 1);
789  }
790
791  moveStatePastFakeLParens(State, Newline);
792  moveStatePastScopeOpener(State, Newline);
793  moveStatePastScopeCloser(State);
794  moveStatePastFakeRParens(State);
795
796  if (Current.isStringLiteral() && State.StartOfStringLiteral == 0)
797    State.StartOfStringLiteral = State.Column;
798  if (Current.is(TT_ObjCStringLiteral) && State.StartOfStringLiteral == 0)
799    State.StartOfStringLiteral = State.Column + 1;
800  else if (!Current.isOneOf(tok::comment, tok::identifier, tok::hash) &&
801           !Current.isStringLiteral())
802    State.StartOfStringLiteral = 0;
803
804  State.Column += Current.ColumnWidth;
805  State.NextToken = State.NextToken->Next;
806  unsigned Penalty = breakProtrudingToken(Current, State, DryRun);
807  if (State.Column > getColumnLimit(State)) {
808    unsigned ExcessCharacters = State.Column - getColumnLimit(State);
809    Penalty += Style.PenaltyExcessCharacter * ExcessCharacters;
810  }
811
812  if (Current.Role)
813    Current.Role->formatFromToken(State, this, DryRun);
814  // If the previous has a special role, let it consume tokens as appropriate.
815  // It is necessary to start at the previous token for the only implemented
816  // role (comma separated list). That way, the decision whether or not to break
817  // after the "{" is already done and both options are tried and evaluated.
818  // FIXME: This is ugly, find a better way.
819  if (Previous && Previous->Role)
820    Penalty += Previous->Role->formatAfterToken(State, this, DryRun);
821
822  return Penalty;
823}
824
825void ContinuationIndenter::moveStatePastFakeLParens(LineState &State,
826                                                    bool Newline) {
827  const FormatToken &Current = *State.NextToken;
828  const FormatToken *Previous = Current.getPreviousNonComment();
829
830  // Don't add extra indentation for the first fake parenthesis after
831  // 'return', assignments or opening <({[. The indentation for these cases
832  // is special cased.
833  bool SkipFirstExtraIndent =
834      (Previous && (Previous->opensScope() ||
835                    Previous->isOneOf(tok::semi, tok::kw_return) ||
836                    (Previous->getPrecedence() == prec::Assignment &&
837                     Style.AlignOperands) ||
838                    Previous->is(TT_ObjCMethodExpr)));
839  for (SmallVectorImpl<prec::Level>::const_reverse_iterator
840           I = Current.FakeLParens.rbegin(),
841           E = Current.FakeLParens.rend();
842       I != E; ++I) {
843    ParenState NewParenState = State.Stack.back();
844    NewParenState.ContainsLineBreak = false;
845
846    // Indent from 'LastSpace' unless these are fake parentheses encapsulating
847    // a builder type call after 'return' or, if the alignment after opening
848    // brackets is disabled.
849    if (!Current.isTrailingComment() &&
850        (Style.AlignOperands || *I < prec::Assignment) &&
851        (!Previous || Previous->isNot(tok::kw_return) ||
852         (Style.Language != FormatStyle::LK_Java && *I > 0)) &&
853        (Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign ||
854         *I != prec::Comma || Current.NestingLevel == 0))
855      NewParenState.Indent =
856          std::max(std::max(State.Column, NewParenState.Indent),
857                   State.Stack.back().LastSpace);
858
859    // Don't allow the RHS of an operator to be split over multiple lines unless
860    // there is a line-break right after the operator.
861    // Exclude relational operators, as there, it is always more desirable to
862    // have the LHS 'left' of the RHS.
863    if (Previous && Previous->getPrecedence() != prec::Assignment &&
864        Previous->isOneOf(TT_BinaryOperator, TT_ConditionalExpr) &&
865        Previous->getPrecedence() != prec::Relational) {
866      bool BreakBeforeOperator =
867          Previous->is(tok::lessless) ||
868          (Previous->is(TT_BinaryOperator) &&
869           Style.BreakBeforeBinaryOperators != FormatStyle::BOS_None) ||
870          (Previous->is(TT_ConditionalExpr) &&
871           Style.BreakBeforeTernaryOperators);
872      if ((!Newline && !BreakBeforeOperator) ||
873          (!State.Stack.back().LastOperatorWrapped && BreakBeforeOperator))
874        NewParenState.NoLineBreak = true;
875    }
876
877    // Do not indent relative to the fake parentheses inserted for "." or "->".
878    // This is a special case to make the following to statements consistent:
879    //   OuterFunction(InnerFunctionCall( // break
880    //       ParameterToInnerFunction));
881    //   OuterFunction(SomeObject.InnerFunctionCall( // break
882    //       ParameterToInnerFunction));
883    if (*I > prec::Unknown)
884      NewParenState.LastSpace = std::max(NewParenState.LastSpace, State.Column);
885    if (*I != prec::Conditional && !Current.is(TT_UnaryOperator) &&
886        Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign)
887      NewParenState.StartOfFunctionCall = State.Column;
888
889    // Always indent conditional expressions. Never indent expression where
890    // the 'operator' is ',', ';' or an assignment (i.e. *I <=
891    // prec::Assignment) as those have different indentation rules. Indent
892    // other expression, unless the indentation needs to be skipped.
893    if (*I == prec::Conditional ||
894        (!SkipFirstExtraIndent && *I > prec::Assignment &&
895         !Current.isTrailingComment()))
896      NewParenState.Indent += Style.ContinuationIndentWidth;
897    if ((Previous && !Previous->opensScope()) || *I != prec::Comma)
898      NewParenState.BreakBeforeParameter = false;
899    State.Stack.push_back(NewParenState);
900    SkipFirstExtraIndent = false;
901  }
902}
903
904void ContinuationIndenter::moveStatePastFakeRParens(LineState &State) {
905  for (unsigned i = 0, e = State.NextToken->FakeRParens; i != e; ++i) {
906    unsigned VariablePos = State.Stack.back().VariablePos;
907    if (State.Stack.size() == 1) {
908      // Do not pop the last element.
909      break;
910    }
911    State.Stack.pop_back();
912    State.Stack.back().VariablePos = VariablePos;
913  }
914}
915
916void ContinuationIndenter::moveStatePastScopeOpener(LineState &State,
917                                                    bool Newline) {
918  const FormatToken &Current = *State.NextToken;
919  if (!Current.opensScope())
920    return;
921
922  if (Current.MatchingParen && Current.BlockKind == BK_Block) {
923    moveStateToNewBlock(State);
924    return;
925  }
926
927  unsigned NewIndent;
928  unsigned NewIndentLevel = State.Stack.back().IndentLevel;
929  unsigned LastSpace = State.Stack.back().LastSpace;
930  bool AvoidBinPacking;
931  bool BreakBeforeParameter = false;
932  unsigned NestedBlockIndent = std::max(State.Stack.back().StartOfFunctionCall,
933                                        State.Stack.back().NestedBlockIndent);
934  if (Current.isOneOf(tok::l_brace, TT_ArrayInitializerLSquare)) {
935    if (Current.opensBlockOrBlockTypeList(Style)) {
936      NewIndent = State.Stack.back().NestedBlockIndent + Style.IndentWidth;
937      NewIndent = std::min(State.Column + 2, NewIndent);
938      ++NewIndentLevel;
939    } else {
940      NewIndent = State.Stack.back().LastSpace + Style.ContinuationIndentWidth;
941    }
942    const FormatToken *NextNoComment = Current.getNextNonComment();
943    bool EndsInComma = Current.MatchingParen &&
944                       Current.MatchingParen->Previous &&
945                       Current.MatchingParen->Previous->is(tok::comma);
946    AvoidBinPacking =
947        (Current.is(TT_ArrayInitializerLSquare) && EndsInComma) ||
948        Current.is(TT_DictLiteral) ||
949        Style.Language == FormatStyle::LK_Proto || !Style.BinPackArguments ||
950        (NextNoComment && NextNoComment->is(TT_DesignatedInitializerPeriod));
951    if (Current.ParameterCount > 1)
952      NestedBlockIndent = std::max(NestedBlockIndent, State.Column + 1);
953  } else {
954    NewIndent = Style.ContinuationIndentWidth +
955                std::max(State.Stack.back().LastSpace,
956                         State.Stack.back().StartOfFunctionCall);
957
958    // Ensure that different different brackets force relative alignment, e.g.:
959    // void SomeFunction(vector<  // break
960    //                       int> v);
961    // FIXME: We likely want to do this for more combinations of brackets.
962    // Verify that it is wanted for ObjC, too.
963    if (Current.Tok.getKind() == tok::less &&
964        Current.ParentBracket == tok::l_paren) {
965      NewIndent = std::max(NewIndent, State.Stack.back().Indent);
966      LastSpace = std::max(LastSpace, State.Stack.back().Indent);
967    }
968
969    AvoidBinPacking =
970        (State.Line->MustBeDeclaration && !Style.BinPackParameters) ||
971        (!State.Line->MustBeDeclaration && !Style.BinPackArguments) ||
972        (Style.ExperimentalAutoDetectBinPacking &&
973         (Current.PackingKind == PPK_OnePerLine ||
974          (!BinPackInconclusiveFunctions &&
975           Current.PackingKind == PPK_Inconclusive)));
976    if (Current.is(TT_ObjCMethodExpr) && Current.MatchingParen) {
977      if (Style.ColumnLimit) {
978        // If this '[' opens an ObjC call, determine whether all parameters fit
979        // into one line and put one per line if they don't.
980        if (getLengthToMatchingParen(Current) + State.Column >
981            getColumnLimit(State))
982          BreakBeforeParameter = true;
983      } else {
984        // For ColumnLimit = 0, we have to figure out whether there is or has to
985        // be a line break within this call.
986        for (const FormatToken *Tok = &Current;
987             Tok && Tok != Current.MatchingParen; Tok = Tok->Next) {
988          if (Tok->MustBreakBefore ||
989              (Tok->CanBreakBefore && Tok->NewlinesBefore > 0)) {
990            BreakBeforeParameter = true;
991            break;
992          }
993        }
994      }
995    }
996  }
997  // Generally inherit NoLineBreak from the current scope to nested scope.
998  // However, don't do this for non-empty nested blocks, dict literals and
999  // array literals as these follow different indentation rules.
1000  bool NoLineBreak =
1001      Current.Children.empty() &&
1002      !Current.isOneOf(TT_DictLiteral, TT_ArrayInitializerLSquare) &&
1003      (State.Stack.back().NoLineBreak ||
1004       (Current.is(TT_TemplateOpener) &&
1005        State.Stack.back().ContainsUnwrappedBuilder));
1006  State.Stack.push_back(ParenState(NewIndent, NewIndentLevel, LastSpace,
1007                                   AvoidBinPacking, NoLineBreak));
1008  State.Stack.back().NestedBlockIndent = NestedBlockIndent;
1009  State.Stack.back().BreakBeforeParameter = BreakBeforeParameter;
1010  State.Stack.back().HasMultipleNestedBlocks = Current.BlockParameterCount > 1;
1011}
1012
1013void ContinuationIndenter::moveStatePastScopeCloser(LineState &State) {
1014  const FormatToken &Current = *State.NextToken;
1015  if (!Current.closesScope())
1016    return;
1017
1018  // If we encounter a closing ), ], } or >, we can remove a level from our
1019  // stacks.
1020  if (State.Stack.size() > 1 &&
1021      (Current.isOneOf(tok::r_paren, tok::r_square) ||
1022       (Current.is(tok::r_brace) && State.NextToken != State.Line->First) ||
1023       State.NextToken->is(TT_TemplateCloser)))
1024    State.Stack.pop_back();
1025
1026  if (Current.is(tok::r_square)) {
1027    // If this ends the array subscript expr, reset the corresponding value.
1028    const FormatToken *NextNonComment = Current.getNextNonComment();
1029    if (NextNonComment && NextNonComment->isNot(tok::l_square))
1030      State.Stack.back().StartOfArraySubscripts = 0;
1031  }
1032}
1033
1034void ContinuationIndenter::moveStateToNewBlock(LineState &State) {
1035  unsigned NestedBlockIndent = State.Stack.back().NestedBlockIndent;
1036  // ObjC block sometimes follow special indentation rules.
1037  unsigned NewIndent =
1038      NestedBlockIndent + (State.NextToken->is(TT_ObjCBlockLBrace)
1039                               ? Style.ObjCBlockIndentWidth
1040                               : Style.IndentWidth);
1041  State.Stack.push_back(ParenState(
1042      NewIndent, /*NewIndentLevel=*/State.Stack.back().IndentLevel + 1,
1043      State.Stack.back().LastSpace, /*AvoidBinPacking=*/true,
1044      /*NoLineBreak=*/false));
1045  State.Stack.back().NestedBlockIndent = NestedBlockIndent;
1046  State.Stack.back().BreakBeforeParameter = true;
1047}
1048
1049unsigned ContinuationIndenter::addMultilineToken(const FormatToken &Current,
1050                                                 LineState &State) {
1051  if (!Current.IsMultiline)
1052    return 0;
1053
1054  // Break before further function parameters on all levels.
1055  for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
1056    State.Stack[i].BreakBeforeParameter = true;
1057
1058  unsigned ColumnsUsed = State.Column;
1059  // We can only affect layout of the first and the last line, so the penalty
1060  // for all other lines is constant, and we ignore it.
1061  State.Column = Current.LastLineColumnWidth;
1062
1063  if (ColumnsUsed > getColumnLimit(State))
1064    return Style.PenaltyExcessCharacter * (ColumnsUsed - getColumnLimit(State));
1065  return 0;
1066}
1067
1068unsigned ContinuationIndenter::breakProtrudingToken(const FormatToken &Current,
1069                                                    LineState &State,
1070                                                    bool DryRun) {
1071  // Don't break multi-line tokens other than block comments. Instead, just
1072  // update the state.
1073  if (Current.isNot(TT_BlockComment) && Current.IsMultiline)
1074    return addMultilineToken(Current, State);
1075
1076  // Don't break implicit string literals or import statements.
1077  if (Current.is(TT_ImplicitStringLiteral) ||
1078      State.Line->Type == LT_ImportStatement)
1079    return 0;
1080
1081  if (!Current.isStringLiteral() && !Current.is(tok::comment))
1082    return 0;
1083
1084  std::unique_ptr<BreakableToken> Token;
1085  unsigned StartColumn = State.Column - Current.ColumnWidth;
1086  unsigned ColumnLimit = getColumnLimit(State);
1087
1088  if (Current.isStringLiteral()) {
1089    // FIXME: String literal breaking is currently disabled for Java and JS, as
1090    // it requires strings to be merged using "+" which we don't support.
1091    if (Style.Language == FormatStyle::LK_Java ||
1092        Style.Language == FormatStyle::LK_JavaScript ||
1093        !Style.BreakStringLiterals)
1094      return 0;
1095
1096    // Don't break string literals inside preprocessor directives (except for
1097    // #define directives, as their contents are stored in separate lines and
1098    // are not affected by this check).
1099    // This way we avoid breaking code with line directives and unknown
1100    // preprocessor directives that contain long string literals.
1101    if (State.Line->Type == LT_PreprocessorDirective)
1102      return 0;
1103    // Exempts unterminated string literals from line breaking. The user will
1104    // likely want to terminate the string before any line breaking is done.
1105    if (Current.IsUnterminatedLiteral)
1106      return 0;
1107
1108    StringRef Text = Current.TokenText;
1109    StringRef Prefix;
1110    StringRef Postfix;
1111    bool IsNSStringLiteral = false;
1112    // FIXME: Handle whitespace between '_T', '(', '"..."', and ')'.
1113    // FIXME: Store Prefix and Suffix (or PrefixLength and SuffixLength to
1114    // reduce the overhead) for each FormatToken, which is a string, so that we
1115    // don't run multiple checks here on the hot path.
1116    if (Text.startswith("\"") && Current.Previous &&
1117        Current.Previous->is(tok::at)) {
1118      IsNSStringLiteral = true;
1119      Prefix = "@\"";
1120    }
1121    if ((Text.endswith(Postfix = "\"") &&
1122         (IsNSStringLiteral || Text.startswith(Prefix = "\"") ||
1123          Text.startswith(Prefix = "u\"") || Text.startswith(Prefix = "U\"") ||
1124          Text.startswith(Prefix = "u8\"") ||
1125          Text.startswith(Prefix = "L\""))) ||
1126        (Text.startswith(Prefix = "_T(\"") && Text.endswith(Postfix = "\")"))) {
1127      Token.reset(new BreakableStringLiteral(
1128          Current, State.Line->Level, StartColumn, Prefix, Postfix,
1129          State.Line->InPPDirective, Encoding, Style));
1130    } else {
1131      return 0;
1132    }
1133  } else if (Current.is(TT_BlockComment)) {
1134    if (!Current.isTrailingComment() || !Style.ReflowComments ||
1135        CommentPragmasRegex.match(Current.TokenText.substr(2)))
1136      return addMultilineToken(Current, State);
1137    Token.reset(new BreakableBlockComment(
1138        Current, State.Line->Level, StartColumn, Current.OriginalColumn,
1139        !Current.Previous, State.Line->InPPDirective, Encoding, Style));
1140  } else if (Current.is(TT_LineComment) &&
1141             (Current.Previous == nullptr ||
1142              Current.Previous->isNot(TT_ImplicitStringLiteral))) {
1143    if (!Style.ReflowComments ||
1144        CommentPragmasRegex.match(Current.TokenText.substr(2)))
1145      return 0;
1146    Token.reset(new BreakableLineComment(Current, State.Line->Level,
1147                                         StartColumn, /*InPPDirective=*/false,
1148                                         Encoding, Style));
1149    // We don't insert backslashes when breaking line comments.
1150    ColumnLimit = Style.ColumnLimit;
1151  } else {
1152    return 0;
1153  }
1154  if (Current.UnbreakableTailLength >= ColumnLimit)
1155    return 0;
1156
1157  unsigned RemainingSpace = ColumnLimit - Current.UnbreakableTailLength;
1158  bool BreakInserted = false;
1159  unsigned Penalty = 0;
1160  unsigned RemainingTokenColumns = 0;
1161  for (unsigned LineIndex = 0, EndIndex = Token->getLineCount();
1162       LineIndex != EndIndex; ++LineIndex) {
1163    if (!DryRun)
1164      Token->replaceWhitespaceBefore(LineIndex, Whitespaces);
1165    unsigned TailOffset = 0;
1166    RemainingTokenColumns =
1167        Token->getLineLengthAfterSplit(LineIndex, TailOffset, StringRef::npos);
1168    while (RemainingTokenColumns > RemainingSpace) {
1169      BreakableToken::Split Split =
1170          Token->getSplit(LineIndex, TailOffset, ColumnLimit);
1171      if (Split.first == StringRef::npos) {
1172        // The last line's penalty is handled in addNextStateToQueue().
1173        if (LineIndex < EndIndex - 1)
1174          Penalty += Style.PenaltyExcessCharacter *
1175                     (RemainingTokenColumns - RemainingSpace);
1176        break;
1177      }
1178      assert(Split.first != 0);
1179      unsigned NewRemainingTokenColumns = Token->getLineLengthAfterSplit(
1180          LineIndex, TailOffset + Split.first + Split.second, StringRef::npos);
1181
1182      // We can remove extra whitespace instead of breaking the line.
1183      if (RemainingTokenColumns + 1 - Split.second <= RemainingSpace) {
1184        RemainingTokenColumns = 0;
1185        if (!DryRun)
1186          Token->replaceWhitespace(LineIndex, TailOffset, Split, Whitespaces);
1187        break;
1188      }
1189
1190      // When breaking before a tab character, it may be moved by a few columns,
1191      // but will still be expanded to the next tab stop, so we don't save any
1192      // columns.
1193      if (NewRemainingTokenColumns == RemainingTokenColumns)
1194        break;
1195
1196      assert(NewRemainingTokenColumns < RemainingTokenColumns);
1197      if (!DryRun)
1198        Token->insertBreak(LineIndex, TailOffset, Split, Whitespaces);
1199      Penalty += Current.SplitPenalty;
1200      unsigned ColumnsUsed =
1201          Token->getLineLengthAfterSplit(LineIndex, TailOffset, Split.first);
1202      if (ColumnsUsed > ColumnLimit) {
1203        Penalty += Style.PenaltyExcessCharacter * (ColumnsUsed - ColumnLimit);
1204      }
1205      TailOffset += Split.first + Split.second;
1206      RemainingTokenColumns = NewRemainingTokenColumns;
1207      BreakInserted = true;
1208    }
1209  }
1210
1211  State.Column = RemainingTokenColumns;
1212
1213  if (BreakInserted) {
1214    // If we break the token inside a parameter list, we need to break before
1215    // the next parameter on all levels, so that the next parameter is clearly
1216    // visible. Line comments already introduce a break.
1217    if (Current.isNot(TT_LineComment)) {
1218      for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
1219        State.Stack[i].BreakBeforeParameter = true;
1220    }
1221
1222    Penalty += Current.isStringLiteral() ? Style.PenaltyBreakString
1223                                         : Style.PenaltyBreakComment;
1224
1225    State.Stack.back().LastSpace = StartColumn;
1226  }
1227  return Penalty;
1228}
1229
1230unsigned ContinuationIndenter::getColumnLimit(const LineState &State) const {
1231  // In preprocessor directives reserve two chars for trailing " \"
1232  return Style.ColumnLimit - (State.Line->InPPDirective ? 2 : 0);
1233}
1234
1235bool ContinuationIndenter::nextIsMultilineString(const LineState &State) {
1236  const FormatToken &Current = *State.NextToken;
1237  if (!Current.isStringLiteral() || Current.is(TT_ImplicitStringLiteral))
1238    return false;
1239  // We never consider raw string literals "multiline" for the purpose of
1240  // AlwaysBreakBeforeMultilineStrings implementation as they are special-cased
1241  // (see TokenAnnotator::mustBreakBefore().
1242  if (Current.TokenText.startswith("R\""))
1243    return false;
1244  if (Current.IsMultiline)
1245    return true;
1246  if (Current.getNextNonComment() &&
1247      Current.getNextNonComment()->isStringLiteral())
1248    return true; // Implicit concatenation.
1249  if (Style.ColumnLimit != 0 &&
1250      State.Column + Current.ColumnWidth + Current.UnbreakableTailLength >
1251          Style.ColumnLimit)
1252    return true; // String will be split.
1253  return false;
1254}
1255
1256} // namespace format
1257} // namespace clang
1258