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llvm-project/clang/lib/Format/ContinuationIndenter.cpp

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//===--- ContinuationIndenter.cpp - Format C++ code -----------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief This file implements the continuation indenter.
///
//===----------------------------------------------------------------------===//
#include "BreakableToken.h"
#include "ContinuationIndenter.h"
#include "WhitespaceManager.h"
#include "clang/Basic/OperatorPrecedence.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Format/Format.h"
#include "llvm/Support/Debug.h"
#include <string>
#define DEBUG_TYPE "format-formatter"
namespace clang {
namespace format {
// Returns the length of everything up to the first possible line break after
// the ), ], } or > matching \c Tok.
static unsigned getLengthToMatchingParen(const FormatToken &Tok) {
if (!Tok.MatchingParen)
return 0;
FormatToken *End = Tok.MatchingParen;
while (End->Next && !End->Next->CanBreakBefore) {
End = End->Next;
}
return End->TotalLength - Tok.TotalLength + 1;
}
// Returns \c true if \c Tok is the "." or "->" of a call and starts the next
// segment of a builder type call.
static bool startsSegmentOfBuilderTypeCall(const FormatToken &Tok) {
return Tok.isMemberAccess() && Tok.Previous && Tok.Previous->closesScope();
}
// Returns \c true if \c Current starts a new parameter.
static bool startsNextParameter(const FormatToken &Current,
const FormatStyle &Style) {
const FormatToken &Previous = *Current.Previous;
if (Current.Type == TT_CtorInitializerComma &&
Style.BreakConstructorInitializersBeforeComma)
return true;
return Previous.is(tok::comma) && !Current.isTrailingComment() &&
(Previous.Type != TT_CtorInitializerComma ||
!Style.BreakConstructorInitializersBeforeComma);
}
ContinuationIndenter::ContinuationIndenter(const FormatStyle &Style,
SourceManager &SourceMgr,
WhitespaceManager &Whitespaces,
encoding::Encoding Encoding,
bool BinPackInconclusiveFunctions)
: Style(Style), SourceMgr(SourceMgr), Whitespaces(Whitespaces),
Encoding(Encoding),
BinPackInconclusiveFunctions(BinPackInconclusiveFunctions),
CommentPragmasRegex(Style.CommentPragmas) {}
LineState ContinuationIndenter::getInitialState(unsigned FirstIndent,
const AnnotatedLine *Line,
bool DryRun) {
LineState State;
State.FirstIndent = FirstIndent;
State.Column = FirstIndent;
State.Line = Line;
State.NextToken = Line->First;
State.Stack.push_back(ParenState(FirstIndent, Line->Level, FirstIndent,
/*AvoidBinPacking=*/false,
/*NoLineBreak=*/false));
State.LineContainsContinuedForLoopSection = false;
State.StartOfStringLiteral = 0;
State.StartOfLineLevel = 0;
State.LowestLevelOnLine = 0;
State.IgnoreStackForComparison = false;
// The first token has already been indented and thus consumed.
moveStateToNextToken(State, DryRun, /*Newline=*/false);
return State;
}
bool ContinuationIndenter::canBreak(const LineState &State) {
const FormatToken &Current = *State.NextToken;
const FormatToken &Previous = *Current.Previous;
assert(&Previous == Current.Previous);
if (!Current.CanBreakBefore && !(State.Stack.back().BreakBeforeClosingBrace &&
Current.closesBlockTypeList(Style)))
return false;
// The opening "{" of a braced list has to be on the same line as the first
// element if it is nested in another braced init list or function call.
if (!Current.MustBreakBefore && Previous.is(tok::l_brace) &&
Previous.Type != TT_DictLiteral && Previous.BlockKind == BK_BracedInit &&
Previous.Previous &&
Previous.Previous->isOneOf(tok::l_brace, tok::l_paren, tok::comma))
return false;
// This prevents breaks like:
// ...
// SomeParameter, OtherParameter).DoSomething(
// ...
// As they hide "DoSomething" and are generally bad for readability.
if (Previous.opensScope() && Previous.isNot(tok::l_brace) &&
State.LowestLevelOnLine < State.StartOfLineLevel)
return false;
if (Current.isMemberAccess() && State.Stack.back().ContainsUnwrappedBuilder)
return false;
// Don't create a 'hanging' indent if there are multiple blocks in a single
// statement.
if (Style.Language == FormatStyle::LK_JavaScript &&
Previous.is(tok::l_brace) && State.Stack.size() > 1 &&
State.Stack[State.Stack.size() - 2].JSFunctionInlined &&
State.Stack[State.Stack.size() - 2].HasMultipleNestedBlocks)
return false;
return !State.Stack.back().NoLineBreak;
}
bool ContinuationIndenter::mustBreak(const LineState &State) {
const FormatToken &Current = *State.NextToken;
const FormatToken &Previous = *Current.Previous;
if (Current.MustBreakBefore || Current.Type == TT_InlineASMColon)
return true;
if (State.Stack.back().BreakBeforeClosingBrace &&
Current.closesBlockTypeList(Style))
return true;
if (Previous.is(tok::semi) && State.LineContainsContinuedForLoopSection)
return true;
if ((startsNextParameter(Current, Style) || Previous.is(tok::semi) ||
(Style.BreakBeforeTernaryOperators &&
(Current.is(tok::question) || (Current.Type == TT_ConditionalExpr &&
Previous.isNot(tok::question)))) ||
(!Style.BreakBeforeTernaryOperators &&
(Previous.is(tok::question) || Previous.Type == TT_ConditionalExpr))) &&
State.Stack.back().BreakBeforeParameter && !Current.isTrailingComment() &&
!Current.isOneOf(tok::r_paren, tok::r_brace))
return true;
if (Style.AlwaysBreakBeforeMultilineStrings &&
State.Column > State.Stack.back().Indent && // Breaking saves columns.
!Previous.isOneOf(tok::kw_return, tok::lessless, tok::at) &&
Previous.Type != TT_InlineASMColon &&
Previous.Type != TT_ConditionalExpr && nextIsMultilineString(State))
return true;
if (((Previous.Type == TT_DictLiteral && Previous.is(tok::l_brace)) ||
Previous.Type == TT_ArrayInitializerLSquare) &&
Style.ColumnLimit > 0 &&
getLengthToMatchingParen(Previous) + State.Column > getColumnLimit(State))
return true;
if (Current.Type == TT_CtorInitializerColon &&
((Style.AllowShortFunctionsOnASingleLine != FormatStyle::SFS_All) ||
Style.BreakConstructorInitializersBeforeComma || Style.ColumnLimit != 0))
return true;
if (State.Column < getNewLineColumn(State))
return false;
if (!Style.BreakBeforeBinaryOperators) {
// If we need to break somewhere inside the LHS of a binary expression, we
// should also break after the operator. Otherwise, the formatting would
// hide the operator precedence, e.g. in:
// if (aaaaaaaaaaaaaa ==
// bbbbbbbbbbbbbb && c) {..
// For comparisons, we only apply this rule, if the LHS is a binary
// expression itself as otherwise, the line breaks seem superfluous.
// We need special cases for ">>" which we have split into two ">" while
// lexing in order to make template parsing easier.
//
// FIXME: We'll need something similar for styles that break before binary
// operators.
bool IsComparison = (Previous.getPrecedence() == prec::Relational ||
Previous.getPrecedence() == prec::Equality) &&
Previous.Previous &&
Previous.Previous->Type != TT_BinaryOperator; // For >>.
bool LHSIsBinaryExpr =
Previous.Previous && Previous.Previous->EndsBinaryExpression;
if (Previous.Type == TT_BinaryOperator &&
(!IsComparison || LHSIsBinaryExpr) &&
Current.Type != TT_BinaryOperator && // For >>.
!Current.isTrailingComment() && !Previous.is(tok::lessless) &&
Previous.getPrecedence() != prec::Assignment &&
State.Stack.back().BreakBeforeParameter)
return true;
}
// Same as above, but for the first "<<" operator.
if (Current.is(tok::lessless) && Current.Type != TT_OverloadedOperator &&
State.Stack.back().BreakBeforeParameter &&
State.Stack.back().FirstLessLess == 0)
return true;
if (Current.Type == TT_SelectorName &&
State.Stack.back().ObjCSelectorNameFound &&
State.Stack.back().BreakBeforeParameter)
return true;
if (Previous.ClosesTemplateDeclaration && Current.NestingLevel == 0 &&
!Current.isTrailingComment())
return true;
if ((Current.Type == TT_StartOfName || Current.is(tok::kw_operator)) &&
State.Line->MightBeFunctionDecl &&
State.Stack.back().BreakBeforeParameter && Current.NestingLevel == 0)
return true;
if (startsSegmentOfBuilderTypeCall(Current) &&
(State.Stack.back().CallContinuation != 0 ||
(State.Stack.back().BreakBeforeParameter &&
State.Stack.back().ContainsUnwrappedBuilder)))
return true;
// The following could be precomputed as they do not depend on the state.
// However, as they should take effect only if the UnwrappedLine does not fit
// into the ColumnLimit, they are checked here in the ContinuationIndenter.
if (Style.ColumnLimit != 0 && Previous.BlockKind == BK_Block &&
Previous.is(tok::l_brace) && !Current.isOneOf(tok::r_brace, tok::comment))
return true;
return false;
}
unsigned ContinuationIndenter::addTokenToState(LineState &State, bool Newline,
bool DryRun,
unsigned ExtraSpaces) {
const FormatToken &Current = *State.NextToken;
assert(!State.Stack.empty());
if ((Current.Type == TT_ImplicitStringLiteral &&
(Current.Previous->Tok.getIdentifierInfo() == nullptr ||
Current.Previous->Tok.getIdentifierInfo()->getPPKeywordID() ==
tok::pp_not_keyword))) {
// FIXME: Is this correct?
int WhitespaceLength = SourceMgr.getSpellingColumnNumber(
State.NextToken->WhitespaceRange.getEnd()) -
SourceMgr.getSpellingColumnNumber(
State.NextToken->WhitespaceRange.getBegin());
State.Column += WhitespaceLength;
moveStateToNextToken(State, DryRun, /*Newline=*/false);
return 0;
}
unsigned Penalty = 0;
if (Newline)
Penalty = addTokenOnNewLine(State, DryRun);
else
addTokenOnCurrentLine(State, DryRun, ExtraSpaces);
return moveStateToNextToken(State, DryRun, Newline) + Penalty;
}
void ContinuationIndenter::addTokenOnCurrentLine(LineState &State, bool DryRun,
unsigned ExtraSpaces) {
FormatToken &Current = *State.NextToken;
const FormatToken &Previous = *State.NextToken->Previous;
if (Current.is(tok::equal) &&
(State.Line->First->is(tok::kw_for) || Current.NestingLevel == 0) &&
State.Stack.back().VariablePos == 0) {
State.Stack.back().VariablePos = State.Column;
// Move over * and & if they are bound to the variable name.
const FormatToken *Tok = &Previous;
while (Tok && State.Stack.back().VariablePos >= Tok->ColumnWidth) {
State.Stack.back().VariablePos -= Tok->ColumnWidth;
if (Tok->SpacesRequiredBefore != 0)
break;
Tok = Tok->Previous;
}
if (Previous.PartOfMultiVariableDeclStmt)
State.Stack.back().LastSpace = State.Stack.back().VariablePos;
}
unsigned Spaces = Current.SpacesRequiredBefore + ExtraSpaces;
if (!DryRun)
Whitespaces.replaceWhitespace(Current, /*Newlines=*/0, /*IndentLevel=*/0,
Spaces, State.Column + Spaces);
if (Current.Type == TT_SelectorName &&
!State.Stack.back().ObjCSelectorNameFound) {
if (Current.LongestObjCSelectorName == 0)
State.Stack.back().AlignColons = false;
else if (State.Stack.back().Indent + Current.LongestObjCSelectorName >
State.Column + Spaces + Current.ColumnWidth)
State.Stack.back().ColonPos =
State.Stack.back().Indent + Current.LongestObjCSelectorName;
else
State.Stack.back().ColonPos = State.Column + Spaces + Current.ColumnWidth;
}
if (Previous.opensScope() && Previous.Type != TT_ObjCMethodExpr &&
(Current.Type != TT_LineComment || Previous.BlockKind == BK_BracedInit))
State.Stack.back().Indent = State.Column + Spaces;
if (State.Stack.back().AvoidBinPacking && startsNextParameter(Current, Style))
State.Stack.back().NoLineBreak = true;
if (startsSegmentOfBuilderTypeCall(Current))
State.Stack.back().ContainsUnwrappedBuilder = true;
State.Column += Spaces;
if (Current.isNot(tok::comment) && Previous.is(tok::l_paren) &&
Previous.Previous && Previous.Previous->isOneOf(tok::kw_if, tok::kw_for))
// Treat the condition inside an if as if it was a second function
// parameter, i.e. let nested calls have a continuation indent.
State.Stack.back().LastSpace = State.Column;
else if (!Current.isOneOf(tok::comment, tok::caret) &&
(Previous.is(tok::comma) ||
(Previous.is(tok::colon) && Previous.Type == TT_ObjCMethodExpr)))
State.Stack.back().LastSpace = State.Column;
else if ((Previous.Type == TT_BinaryOperator ||
Previous.Type == TT_ConditionalExpr ||
Previous.Type == TT_CtorInitializerColon) &&
((Previous.getPrecedence() != prec::Assignment &&
(Previous.isNot(tok::lessless) || Previous.OperatorIndex != 0 ||
!Previous.LastOperator)) ||
Current.StartsBinaryExpression))
// Always indent relative to the RHS of the expression unless this is a
// simple assignment without binary expression on the RHS. Also indent
// relative to unary operators and the colons of constructor initializers.
State.Stack.back().LastSpace = State.Column;
else if (Previous.Type == TT_InheritanceColon) {
State.Stack.back().Indent = State.Column;
State.Stack.back().LastSpace = State.Column;
} else if (Previous.opensScope()) {
// If a function has a trailing call, indent all parameters from the
// opening parenthesis. This avoids confusing indents like:
// OuterFunction(InnerFunctionCall( // break
// ParameterToInnerFunction)) // break
// .SecondInnerFunctionCall();
bool HasTrailingCall = false;
if (Previous.MatchingParen) {
const FormatToken *Next = Previous.MatchingParen->getNextNonComment();
HasTrailingCall = Next && Next->isMemberAccess();
}
if (HasTrailingCall &&
State.Stack[State.Stack.size() - 2].CallContinuation == 0)
State.Stack.back().LastSpace = State.Column;
}
}
unsigned ContinuationIndenter::addTokenOnNewLine(LineState &State,
bool DryRun) {
FormatToken &Current = *State.NextToken;
const FormatToken &Previous = *State.NextToken->Previous;
// Extra penalty that needs to be added because of the way certain line
// breaks are chosen.
unsigned Penalty = 0;
const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
const FormatToken *NextNonComment = Previous.getNextNonComment();
if (!NextNonComment)
NextNonComment = &Current;
// The first line break on any NestingLevel causes an extra penalty in order
// prefer similar line breaks.
if (!State.Stack.back().ContainsLineBreak)
Penalty += 15;
State.Stack.back().ContainsLineBreak = true;
Penalty += State.NextToken->SplitPenalty;
// Breaking before the first "<<" is generally not desirable if the LHS is
// short. Also always add the penalty if the LHS is split over mutliple lines
// to avoid unnecessary line breaks that just work around this penalty.
if (NextNonComment->is(tok::lessless) &&
State.Stack.back().FirstLessLess == 0 &&
(State.Column <= Style.ColumnLimit / 3 ||
State.Stack.back().BreakBeforeParameter))
Penalty += Style.PenaltyBreakFirstLessLess;
State.Column = getNewLineColumn(State);
if (NextNonComment->isMemberAccess()) {
if (State.Stack.back().CallContinuation == 0)
State.Stack.back().CallContinuation = State.Column;
} else if (NextNonComment->Type == TT_SelectorName) {
if (!State.Stack.back().ObjCSelectorNameFound) {
if (NextNonComment->LongestObjCSelectorName == 0) {
State.Stack.back().AlignColons = false;
} else {
State.Stack.back().ColonPos =
State.Stack.back().Indent + NextNonComment->LongestObjCSelectorName;
}
} else if (State.Stack.back().AlignColons &&
State.Stack.back().ColonPos <= NextNonComment->ColumnWidth) {
State.Stack.back().ColonPos = State.Column + NextNonComment->ColumnWidth;
}
} else if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
(PreviousNonComment->Type == TT_ObjCMethodExpr ||
PreviousNonComment->Type == TT_DictLiteral)) {
// FIXME: This is hacky, find a better way. The problem is that in an ObjC
// method expression, the block should be aligned to the line starting it,
// e.g.:
// [aaaaaaaaaaaaaaa aaaaaaaaa: \\ break for some reason
// ^(int *i) {
// // ...
// }];
// Thus, we set LastSpace of the next higher NestingLevel, to which we move
// when we consume all of the "}"'s FakeRParens at the "{".
if (State.Stack.size() > 1)
State.Stack[State.Stack.size() - 2].LastSpace =
std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) +
Style.ContinuationIndentWidth;
}
if ((Previous.isOneOf(tok::comma, tok::semi) &&
!State.Stack.back().AvoidBinPacking) ||
Previous.Type == TT_BinaryOperator)
State.Stack.back().BreakBeforeParameter = false;
if (Previous.Type == TT_TemplateCloser && Current.NestingLevel == 0)
State.Stack.back().BreakBeforeParameter = false;
if (NextNonComment->is(tok::question) ||
(PreviousNonComment && PreviousNonComment->is(tok::question)))
State.Stack.back().BreakBeforeParameter = true;
if (!DryRun) {
unsigned Newlines = std::max(
1u, std::min(Current.NewlinesBefore, Style.MaxEmptyLinesToKeep + 1));
Whitespaces.replaceWhitespace(Current, Newlines,
State.Stack.back().IndentLevel, State.Column,
State.Column, State.Line->InPPDirective);
}
if (!Current.isTrailingComment())
State.Stack.back().LastSpace = State.Column;
State.StartOfLineLevel = Current.NestingLevel;
State.LowestLevelOnLine = Current.NestingLevel;
// Any break on this level means that the parent level has been broken
// and we need to avoid bin packing there.
bool JavaScriptFormat = Style.Language == FormatStyle::LK_JavaScript &&
Current.is(tok::r_brace) &&
State.Stack.size() > 1 &&
State.Stack[State.Stack.size() - 2].JSFunctionInlined;
if (!JavaScriptFormat) {
for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i) {
State.Stack[i].BreakBeforeParameter = true;
}
}
if (PreviousNonComment &&
!PreviousNonComment->isOneOf(tok::comma, tok::semi) &&
PreviousNonComment->Type != TT_TemplateCloser &&
PreviousNonComment->Type != TT_BinaryOperator &&
Current.Type != TT_BinaryOperator && !PreviousNonComment->opensScope())
State.Stack.back().BreakBeforeParameter = true;
// If we break after { or the [ of an array initializer, we should also break
// before the corresponding } or ].
if (PreviousNonComment &&
(PreviousNonComment->is(tok::l_brace) ||
PreviousNonComment->Type == TT_ArrayInitializerLSquare))
State.Stack.back().BreakBeforeClosingBrace = true;
if (State.Stack.back().AvoidBinPacking) {
// If we are breaking after '(', '{', '<', this is not bin packing
// unless AllowAllParametersOfDeclarationOnNextLine is false or this is a
// dict/object literal.
if (!(Previous.isOneOf(tok::l_paren, tok::l_brace) ||
Previous.Type == TT_BinaryOperator) ||
(!Style.AllowAllParametersOfDeclarationOnNextLine &&
State.Line->MustBeDeclaration) ||
Previous.Type == TT_DictLiteral)
State.Stack.back().BreakBeforeParameter = true;
}
return Penalty;
}
unsigned ContinuationIndenter::getNewLineColumn(const LineState &State) {
if (!State.NextToken || !State.NextToken->Previous)
return 0;
FormatToken &Current = *State.NextToken;
const FormatToken &Previous = *State.NextToken->Previous;
// If we are continuing an expression, we want to use the continuation indent.
unsigned ContinuationIndent =
std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) +
Style.ContinuationIndentWidth;
const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
const FormatToken *NextNonComment = Previous.getNextNonComment();
if (!NextNonComment)
NextNonComment = &Current;
if (NextNonComment->is(tok::l_brace) && NextNonComment->BlockKind == BK_Block)
return Current.NestingLevel == 0 ? State.FirstIndent
: State.Stack.back().Indent;
if (Current.isOneOf(tok::r_brace, tok::r_square)) {
if (State.Stack.size() > 1 &&
State.Stack[State.Stack.size() - 2].JSFunctionInlined)
return State.FirstIndent;
if (Current.closesBlockTypeList(Style) ||
(Current.MatchingParen &&
Current.MatchingParen->BlockKind == BK_BracedInit))
return State.Stack[State.Stack.size() - 2].LastSpace;
else
return State.FirstIndent;
}
if (Current.is(tok::identifier) && Current.Next &&
Current.Next->Type == TT_DictLiteral)
return State.Stack.back().Indent;
if (NextNonComment->isStringLiteral() && State.StartOfStringLiteral != 0)
return State.StartOfStringLiteral;
if (NextNonComment->is(tok::lessless) &&
State.Stack.back().FirstLessLess != 0)
return State.Stack.back().FirstLessLess;
if (NextNonComment->isMemberAccess()) {
if (State.Stack.back().CallContinuation == 0) {
return ContinuationIndent;
} else {
return State.Stack.back().CallContinuation;
}
}
if (State.Stack.back().QuestionColumn != 0 &&
((NextNonComment->is(tok::colon) &&
NextNonComment->Type == TT_ConditionalExpr) ||
Previous.Type == TT_ConditionalExpr))
return State.Stack.back().QuestionColumn;
if (Previous.is(tok::comma) && State.Stack.back().VariablePos != 0)
return State.Stack.back().VariablePos;
if ((PreviousNonComment && (PreviousNonComment->ClosesTemplateDeclaration ||
PreviousNonComment->Type == TT_AttributeParen)) ||
((NextNonComment->Type == TT_StartOfName ||
NextNonComment->is(tok::kw_operator)) &&
Current.NestingLevel == 0 &&
(!Style.IndentFunctionDeclarationAfterType ||
State.Line->StartsDefinition)))
return std::max(State.Stack.back().LastSpace, State.Stack.back().Indent);
if (NextNonComment->Type == TT_SelectorName) {
if (!State.Stack.back().ObjCSelectorNameFound) {
if (NextNonComment->LongestObjCSelectorName == 0) {
return State.Stack.back().Indent;
} else {
return State.Stack.back().Indent +
NextNonComment->LongestObjCSelectorName -
NextNonComment->ColumnWidth;
}
} else if (!State.Stack.back().AlignColons) {
return State.Stack.back().Indent;
} else if (State.Stack.back().ColonPos > NextNonComment->ColumnWidth) {
return State.Stack.back().ColonPos - NextNonComment->ColumnWidth;
} else {
return State.Stack.back().Indent;
}
}
if (NextNonComment->Type == TT_ArraySubscriptLSquare) {
if (State.Stack.back().StartOfArraySubscripts != 0)
return State.Stack.back().StartOfArraySubscripts;
else
return ContinuationIndent;
}
if (NextNonComment->Type == TT_StartOfName ||
Previous.isOneOf(tok::coloncolon, tok::equal)) {
return ContinuationIndent;
}
if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
(PreviousNonComment->Type == TT_ObjCMethodExpr ||
PreviousNonComment->Type == TT_DictLiteral))
return ContinuationIndent;
if (NextNonComment->Type == TT_CtorInitializerColon)
return State.FirstIndent + Style.ConstructorInitializerIndentWidth;
if (NextNonComment->Type == TT_CtorInitializerComma)
return State.Stack.back().Indent;
if (State.Stack.back().Indent == State.FirstIndent && PreviousNonComment &&
PreviousNonComment->isNot(tok::r_brace))
// Ensure that we fall back to the continuation indent width instead of
// just flushing continuations left.
return State.Stack.back().Indent + Style.ContinuationIndentWidth;
return State.Stack.back().Indent;
}
unsigned ContinuationIndenter::moveStateToNextToken(LineState &State,
bool DryRun, bool Newline) {
assert(State.Stack.size());
const FormatToken &Current = *State.NextToken;
if (Current.Type == TT_InheritanceColon)
State.Stack.back().AvoidBinPacking = true;
if (Current.is(tok::lessless) && Current.Type != TT_OverloadedOperator) {
if (State.Stack.back().FirstLessLess == 0)
State.Stack.back().FirstLessLess = State.Column;
else
State.Stack.back().LastOperatorWrapped = Newline;
}
if ((Current.Type == TT_BinaryOperator && Current.isNot(tok::lessless)) ||
Current.Type == TT_ConditionalExpr)
State.Stack.back().LastOperatorWrapped = Newline;
if (Current.Type == TT_ArraySubscriptLSquare &&
State.Stack.back().StartOfArraySubscripts == 0)
State.Stack.back().StartOfArraySubscripts = State.Column;
if ((Current.is(tok::question) && Style.BreakBeforeTernaryOperators) ||
(Current.getPreviousNonComment() && Current.isNot(tok::colon) &&
Current.getPreviousNonComment()->is(tok::question) &&
!Style.BreakBeforeTernaryOperators))
State.Stack.back().QuestionColumn = State.Column;
if (!Current.opensScope() && !Current.closesScope())
State.LowestLevelOnLine =
std::min(State.LowestLevelOnLine, Current.NestingLevel);
if (Current.isMemberAccess())
State.Stack.back().StartOfFunctionCall =
Current.LastOperator ? 0 : State.Column + Current.ColumnWidth;
if (Current.Type == TT_SelectorName)
State.Stack.back().ObjCSelectorNameFound = true;
if (Current.Type == TT_CtorInitializerColon) {
// Indent 2 from the column, so:
// SomeClass::SomeClass()
// : First(...), ...
// Next(...)
// ^ line up here.
State.Stack.back().Indent =
State.Column + (Style.BreakConstructorInitializersBeforeComma ? 0 : 2);
if (Style.ConstructorInitializerAllOnOneLineOrOnePerLine)
State.Stack.back().AvoidBinPacking = true;
State.Stack.back().BreakBeforeParameter = false;
}
// In ObjC method declaration we align on the ":" of parameters, but we need
// to ensure that we indent parameters on subsequent lines by at least our
// continuation indent width.
if (Current.Type == TT_ObjCMethodSpecifier)
State.Stack.back().Indent += Style.ContinuationIndentWidth;
// Insert scopes created by fake parenthesis.
const FormatToken *Previous = Current.getPreviousNonComment();
// Add special behavior to support a format commonly used for JavaScript
// closures:
// SomeFunction(function() {
// foo();
// bar();
// }, a, b, c);
if (Style.Language == FormatStyle::LK_JavaScript) {
if (Current.isNot(tok::comment) && Previous && Previous->is(tok::l_brace) &&
State.Stack.size() > 1) {
if (State.Stack[State.Stack.size() - 2].JSFunctionInlined && Newline) {
for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i) {
State.Stack[i].NoLineBreak = true;
}
}
State.Stack[State.Stack.size() - 2].JSFunctionInlined = false;
}
if (Current.TokenText == "function")
State.Stack.back().JSFunctionInlined = !Newline;
}
moveStatePastFakeLParens(State, Newline);
moveStatePastScopeOpener(State, Newline);
moveStatePastScopeCloser(State);
moveStatePastFakeRParens(State);
if (Current.isStringLiteral() && State.StartOfStringLiteral == 0) {
State.StartOfStringLiteral = State.Column;
} else if (!Current.isOneOf(tok::comment, tok::identifier, tok::hash) &&
!Current.isStringLiteral()) {
State.StartOfStringLiteral = 0;
}
State.Column += Current.ColumnWidth;
State.NextToken = State.NextToken->Next;
unsigned Penalty = breakProtrudingToken(Current, State, DryRun);
if (State.Column > getColumnLimit(State)) {
unsigned ExcessCharacters = State.Column - getColumnLimit(State);
Penalty += Style.PenaltyExcessCharacter * ExcessCharacters;
}
if (Current.Role)
Current.Role->formatFromToken(State, this, DryRun);
// If the previous has a special role, let it consume tokens as appropriate.
// It is necessary to start at the previous token for the only implemented
// role (comma separated list). That way, the decision whether or not to break
// after the "{" is already done and both options are tried and evaluated.
// FIXME: This is ugly, find a better way.
if (Previous && Previous->Role)
Penalty += Previous->Role->formatAfterToken(State, this, DryRun);
return Penalty;
}
void ContinuationIndenter::moveStatePastFakeLParens(LineState &State,
bool Newline) {
const FormatToken &Current = *State.NextToken;
const FormatToken *Previous = Current.getPreviousNonComment();
// Don't add extra indentation for the first fake parenthesis after
// 'return', assignments or opening <({[. The indentation for these cases
// is special cased.
bool SkipFirstExtraIndent =
(Previous && (Previous->opensScope() || Previous->is(tok::kw_return) ||
Previous->getPrecedence() == prec::Assignment ||
Previous->Type == TT_ObjCMethodExpr));
for (SmallVectorImpl<prec::Level>::const_reverse_iterator
I = Current.FakeLParens.rbegin(),
E = Current.FakeLParens.rend();
I != E; ++I) {
ParenState NewParenState = State.Stack.back();
NewParenState.ContainsLineBreak = false;
// Indent from 'LastSpace' unless this the fake parentheses encapsulating a
// builder type call after 'return'. If such a call is line-wrapped, we
// commonly just want to indent from the start of the line.
if (!Previous || Previous->isNot(tok::kw_return) || *I > 0)
NewParenState.Indent =
std::max(std::max(State.Column, NewParenState.Indent),
State.Stack.back().LastSpace);
// Don't allow the RHS of an operator to be split over multiple lines unless
// there is a line-break right after the operator.
// Exclude relational operators, as there, it is always more desirable to
// have the LHS 'left' of the RHS.
if (Previous && Previous->getPrecedence() > prec::Assignment &&
(Previous->Type == TT_BinaryOperator ||
Previous->Type == TT_ConditionalExpr) &&
Previous->getPrecedence() != prec::Relational) {
bool BreakBeforeOperator = Previous->is(tok::lessless) ||
(Previous->Type == TT_BinaryOperator &&
Style.BreakBeforeBinaryOperators) ||
(Previous->Type == TT_ConditionalExpr &&
Style.BreakBeforeTernaryOperators);
if ((!Newline && !BreakBeforeOperator) ||
(!State.Stack.back().LastOperatorWrapped && BreakBeforeOperator))
NewParenState.NoLineBreak = true;
}
// Do not indent relative to the fake parentheses inserted for "." or "->".
// This is a special case to make the following to statements consistent:
// OuterFunction(InnerFunctionCall( // break
// ParameterToInnerFunction));
// OuterFunction(SomeObject.InnerFunctionCall( // break
// ParameterToInnerFunction));
if (*I > prec::Unknown)
NewParenState.LastSpace = std::max(NewParenState.LastSpace, State.Column);
NewParenState.StartOfFunctionCall = State.Column;
// Always indent conditional expressions. Never indent expression where
// the 'operator' is ',', ';' or an assignment (i.e. *I <=
// prec::Assignment) as those have different indentation rules. Indent
// other expression, unless the indentation needs to be skipped.
if (*I == prec::Conditional ||
(!SkipFirstExtraIndent && *I > prec::Assignment &&
!Style.BreakBeforeBinaryOperators))
NewParenState.Indent += Style.ContinuationIndentWidth;
if ((Previous && !Previous->opensScope()) || *I > prec::Comma)
NewParenState.BreakBeforeParameter = false;
State.Stack.push_back(NewParenState);
SkipFirstExtraIndent = false;
}
}
// Remove the fake r_parens after 'Tok'.
static void consumeRParens(LineState& State, const FormatToken &Tok) {
for (unsigned i = 0, e = Tok.FakeRParens; i != e; ++i) {
unsigned VariablePos = State.Stack.back().VariablePos;
assert(State.Stack.size() > 1);
if (State.Stack.size() == 1) {
// Do not pop the last element.
break;
}
State.Stack.pop_back();
State.Stack.back().VariablePos = VariablePos;
}
}
// Returns whether 'Tok' opens or closes a scope requiring special handling
// of the subsequent fake r_parens.
//
// For example, if this is an l_brace starting a nested block, we pretend (wrt.
// to indentation) that we already consumed the corresponding r_brace. Thus, we
// remove all ParenStates caused by fake parentheses that end at the r_brace.
// The net effect of this is that we don't indent relative to the l_brace, if
// the nested block is the last parameter of a function. This formats:
//
// SomeFunction(a, [] {
// f(); // break
// });
//
// instead of:
// SomeFunction(a, [] {
// f(); // break
// });
static bool fakeRParenSpecialCase(const LineState &State) {
const FormatToken &Tok = *State.NextToken;
if (!Tok.MatchingParen)
return false;
const FormatToken *Left = &Tok;
if (Tok.isOneOf(tok::r_brace, tok::r_square))
Left = Tok.MatchingParen;
return !State.Stack.back().HasMultipleNestedBlocks &&
Left->isOneOf(tok::l_brace, tok::l_square) &&
(Left->BlockKind == BK_Block ||
Left->Type == TT_ArrayInitializerLSquare ||
Left->Type == TT_DictLiteral);
}
void ContinuationIndenter::moveStatePastFakeRParens(LineState &State) {
// Don't remove FakeRParens attached to r_braces that surround nested blocks
// as they will have been removed early (see above).
if (fakeRParenSpecialCase(State))
return;
consumeRParens(State, *State.NextToken);
}
void ContinuationIndenter::moveStatePastScopeOpener(LineState &State,
bool Newline) {
const FormatToken &Current = *State.NextToken;
if (!Current.opensScope())
return;
if (Current.MatchingParen && Current.BlockKind == BK_Block) {
moveStateToNewBlock(State);
return;
}
unsigned NewIndent;
unsigned NewIndentLevel = State.Stack.back().IndentLevel;
bool AvoidBinPacking;
bool BreakBeforeParameter = false;
if (Current.is(tok::l_brace) || Current.Type == TT_ArrayInitializerLSquare) {
if (fakeRParenSpecialCase(State))
consumeRParens(State, *Current.MatchingParen);
NewIndent = State.Stack.back().LastSpace;
if (Current.opensBlockTypeList(Style)) {
NewIndent += Style.IndentWidth;
NewIndent = std::min(State.Column + 2, NewIndent);
++NewIndentLevel;
} else {
NewIndent += Style.ContinuationIndentWidth;
NewIndent = std::min(State.Column + 1, NewIndent);
}
const FormatToken *NextNoComment = Current.getNextNonComment();
AvoidBinPacking = Current.Type == TT_ArrayInitializerLSquare ||
Current.Type == TT_DictLiteral ||
Style.Language == FormatStyle::LK_Proto ||
!Style.BinPackParameters ||
(NextNoComment &&
NextNoComment->Type == TT_DesignatedInitializerPeriod);
} else {
NewIndent = Style.ContinuationIndentWidth +
std::max(State.Stack.back().LastSpace,
State.Stack.back().StartOfFunctionCall);
AvoidBinPacking = !Style.BinPackParameters ||
(Style.ExperimentalAutoDetectBinPacking &&
(Current.PackingKind == PPK_OnePerLine ||
(!BinPackInconclusiveFunctions &&
Current.PackingKind == PPK_Inconclusive)));
// If this '[' opens an ObjC call, determine whether all parameters fit
// into one line and put one per line if they don't.
if (Current.Type == TT_ObjCMethodExpr && Style.ColumnLimit != 0 &&
getLengthToMatchingParen(Current) + State.Column >
getColumnLimit(State))
BreakBeforeParameter = true;
}
bool NoLineBreak = State.Stack.back().NoLineBreak ||
(Current.Type == TT_TemplateOpener &&
State.Stack.back().ContainsUnwrappedBuilder);
State.Stack.push_back(ParenState(NewIndent, NewIndentLevel,
State.Stack.back().LastSpace,
AvoidBinPacking, NoLineBreak));
State.Stack.back().BreakBeforeParameter = BreakBeforeParameter;
State.Stack.back().HasMultipleNestedBlocks = Current.BlockParameterCount > 1;
}
void ContinuationIndenter::moveStatePastScopeCloser(LineState &State) {
const FormatToken &Current = *State.NextToken;
if (!Current.closesScope())
return;
// If we encounter a closing ), ], } or >, we can remove a level from our
// stacks.
if (State.Stack.size() > 1 &&
(Current.isOneOf(tok::r_paren, tok::r_square) ||
(Current.is(tok::r_brace) && State.NextToken != State.Line->First) ||
State.NextToken->Type == TT_TemplateCloser))
State.Stack.pop_back();
if (Current.is(tok::r_square)) {
// If this ends the array subscript expr, reset the corresponding value.
const FormatToken *NextNonComment = Current.getNextNonComment();
if (NextNonComment && NextNonComment->isNot(tok::l_square))
State.Stack.back().StartOfArraySubscripts = 0;
}
}
void ContinuationIndenter::moveStateToNewBlock(LineState &State) {
// If we have already found more than one lambda introducers on this level, we
// opt out of this because similarity between the lambdas is more important.
if (fakeRParenSpecialCase(State))
consumeRParens(State, *State.NextToken->MatchingParen);
// For some reason, ObjC blocks are indented like continuations.
unsigned NewIndent = State.Stack.back().LastSpace +
(State.NextToken->Type == TT_ObjCBlockLBrace
? Style.ContinuationIndentWidth
: Style.IndentWidth);
State.Stack.push_back(ParenState(
NewIndent, /*NewIndentLevel=*/State.Stack.back().IndentLevel + 1,
State.Stack.back().LastSpace, /*AvoidBinPacking=*/true,
State.Stack.back().NoLineBreak));
State.Stack.back().BreakBeforeParameter = true;
}
unsigned ContinuationIndenter::addMultilineToken(const FormatToken &Current,
LineState &State) {
// Break before further function parameters on all levels.
for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
State.Stack[i].BreakBeforeParameter = true;
unsigned ColumnsUsed = State.Column;
// We can only affect layout of the first and the last line, so the penalty
// for all other lines is constant, and we ignore it.
State.Column = Current.LastLineColumnWidth;
if (ColumnsUsed > getColumnLimit(State))
return Style.PenaltyExcessCharacter * (ColumnsUsed - getColumnLimit(State));
return 0;
}
static bool getRawStringLiteralPrefixPostfix(StringRef Text, StringRef &Prefix,
StringRef &Postfix) {
if (Text.startswith(Prefix = "R\"") || Text.startswith(Prefix = "uR\"") ||
Text.startswith(Prefix = "UR\"") || Text.startswith(Prefix = "u8R\"") ||
Text.startswith(Prefix = "LR\"")) {
size_t ParenPos = Text.find('(');
if (ParenPos != StringRef::npos) {
StringRef Delimiter =
Text.substr(Prefix.size(), ParenPos - Prefix.size());
Prefix = Text.substr(0, ParenPos + 1);
Postfix = Text.substr(Text.size() - 2 - Delimiter.size());
return Postfix.front() == ')' && Postfix.back() == '"' &&
Postfix.substr(1).startswith(Delimiter);
}
}
return false;
}
unsigned ContinuationIndenter::breakProtrudingToken(const FormatToken &Current,
LineState &State,
bool DryRun) {
// Don't break multi-line tokens other than block comments. Instead, just
// update the state.
if (Current.Type != TT_BlockComment && Current.IsMultiline)
return addMultilineToken(Current, State);
// Don't break implicit string literals.
if (Current.Type == TT_ImplicitStringLiteral)
return 0;
if (!Current.isStringLiteral() && !Current.is(tok::comment))
return 0;
std::unique_ptr<BreakableToken> Token;
unsigned StartColumn = State.Column - Current.ColumnWidth;
unsigned ColumnLimit = getColumnLimit(State);
if (Current.isStringLiteral()) {
// Don't break string literals inside preprocessor directives (except for
// #define directives, as their contents are stored in separate lines and
// are not affected by this check).
// This way we avoid breaking code with line directives and unknown
// preprocessor directives that contain long string literals.
if (State.Line->Type == LT_PreprocessorDirective)
return 0;
// Exempts unterminated string literals from line breaking. The user will
// likely want to terminate the string before any line breaking is done.
if (Current.IsUnterminatedLiteral)
return 0;
StringRef Text = Current.TokenText;
StringRef Prefix;
StringRef Postfix;
bool IsNSStringLiteral = false;
// FIXME: Handle whitespace between '_T', '(', '"..."', and ')'.
// FIXME: Store Prefix and Suffix (or PrefixLength and SuffixLength to
// reduce the overhead) for each FormatToken, which is a string, so that we
// don't run multiple checks here on the hot path.
if (Text.startswith("\"") && Current.Previous &&
Current.Previous->is(tok::at)) {
IsNSStringLiteral = true;
Prefix = "@\"";
}
if ((Text.endswith(Postfix = "\"") &&
(IsNSStringLiteral || Text.startswith(Prefix = "\"") ||
Text.startswith(Prefix = "u\"") || Text.startswith(Prefix = "U\"") ||
Text.startswith(Prefix = "u8\"") ||
Text.startswith(Prefix = "L\""))) ||
(Text.startswith(Prefix = "_T(\"") && Text.endswith(Postfix = "\")")) ||
getRawStringLiteralPrefixPostfix(Text, Prefix, Postfix)) {
Token.reset(new BreakableStringLiteral(
Current, State.Line->Level, StartColumn, Prefix, Postfix,
State.Line->InPPDirective, Encoding, Style));
} else {
return 0;
}
} else if (Current.Type == TT_BlockComment && Current.isTrailingComment()) {
if (CommentPragmasRegex.match(Current.TokenText.substr(2)))
return 0;
Token.reset(new BreakableBlockComment(
Current, State.Line->Level, StartColumn, Current.OriginalColumn,
!Current.Previous, State.Line->InPPDirective, Encoding, Style));
} else if (Current.Type == TT_LineComment &&
(Current.Previous == nullptr ||
Current.Previous->Type != TT_ImplicitStringLiteral)) {
if (CommentPragmasRegex.match(Current.TokenText.substr(2)))
return 0;
Token.reset(new BreakableLineComment(Current, State.Line->Level,
StartColumn, /*InPPDirective=*/false,
Encoding, Style));
// We don't insert backslashes when breaking line comments.
ColumnLimit = Style.ColumnLimit;
} else {
return 0;
}
if (Current.UnbreakableTailLength >= ColumnLimit)
return 0;
unsigned RemainingSpace = ColumnLimit - Current.UnbreakableTailLength;
bool BreakInserted = false;
unsigned Penalty = 0;
unsigned RemainingTokenColumns = 0;
for (unsigned LineIndex = 0, EndIndex = Token->getLineCount();
LineIndex != EndIndex; ++LineIndex) {
if (!DryRun)
Token->replaceWhitespaceBefore(LineIndex, Whitespaces);
unsigned TailOffset = 0;
RemainingTokenColumns =
Token->getLineLengthAfterSplit(LineIndex, TailOffset, StringRef::npos);
while (RemainingTokenColumns > RemainingSpace) {
BreakableToken::Split Split =
Token->getSplit(LineIndex, TailOffset, ColumnLimit);
if (Split.first == StringRef::npos) {
// The last line's penalty is handled in addNextStateToQueue().
if (LineIndex < EndIndex - 1)
Penalty += Style.PenaltyExcessCharacter *
(RemainingTokenColumns - RemainingSpace);
break;
}
assert(Split.first != 0);
unsigned NewRemainingTokenColumns = Token->getLineLengthAfterSplit(
LineIndex, TailOffset + Split.first + Split.second, StringRef::npos);
// We can remove extra whitespace instead of breaking the line.
if (RemainingTokenColumns + 1 - Split.second <= RemainingSpace) {
RemainingTokenColumns = 0;
if (!DryRun)
Token->replaceWhitespace(LineIndex, TailOffset, Split, Whitespaces);
break;
}
// When breaking before a tab character, it may be moved by a few columns,
// but will still be expanded to the next tab stop, so we don't save any
// columns.
if (NewRemainingTokenColumns == RemainingTokenColumns)
break;
assert(NewRemainingTokenColumns < RemainingTokenColumns);
if (!DryRun)
Token->insertBreak(LineIndex, TailOffset, Split, Whitespaces);
Penalty += Current.SplitPenalty;
unsigned ColumnsUsed =
Token->getLineLengthAfterSplit(LineIndex, TailOffset, Split.first);
if (ColumnsUsed > ColumnLimit) {
Penalty += Style.PenaltyExcessCharacter * (ColumnsUsed - ColumnLimit);
}
TailOffset += Split.first + Split.second;
RemainingTokenColumns = NewRemainingTokenColumns;
BreakInserted = true;
}
}
State.Column = RemainingTokenColumns;
if (BreakInserted) {
// If we break the token inside a parameter list, we need to break before
// the next parameter on all levels, so that the next parameter is clearly
// visible. Line comments already introduce a break.
if (Current.Type != TT_LineComment) {
for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
State.Stack[i].BreakBeforeParameter = true;
}
Penalty += Current.isStringLiteral() ? Style.PenaltyBreakString
: Style.PenaltyBreakComment;
State.Stack.back().LastSpace = StartColumn;
}
return Penalty;
}
unsigned ContinuationIndenter::getColumnLimit(const LineState &State) const {
// In preprocessor directives reserve two chars for trailing " \"
return Style.ColumnLimit - (State.Line->InPPDirective ? 2 : 0);
}
bool ContinuationIndenter::nextIsMultilineString(const LineState &State) {
const FormatToken &Current = *State.NextToken;
if (!Current.isStringLiteral() || Current.Type == TT_ImplicitStringLiteral)
return false;
// We never consider raw string literals "multiline" for the purpose of
// AlwaysBreakBeforeMultilineStrings implementation as they are special-cased
// (see TokenAnnotator::mustBreakBefore().
if (Current.TokenText.startswith("R\""))
return false;
if (Current.IsMultiline)
return true;
if (Current.getNextNonComment() &&
Current.getNextNonComment()->isStringLiteral())
return true; // Implicit concatenation.
if (State.Column + Current.ColumnWidth + Current.UnbreakableTailLength >
Style.ColumnLimit)
return true; // String will be split.
return false;
}
} // namespace format
} // namespace clang
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