| //===--- UnwrappedLineFormatter.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. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "UnwrappedLineFormatter.h" |
| #include "WhitespaceManager.h" |
| #include "llvm/Support/Debug.h" |
| |
| #define DEBUG_TYPE "format-formatter" |
| |
| namespace clang { |
| namespace format { |
| |
| namespace { |
| |
| bool startsExternCBlock(const AnnotatedLine &Line) { |
| const FormatToken *Next = Line.First->getNextNonComment(); |
| const FormatToken *NextNext = Next ? Next->getNextNonComment() : nullptr; |
| return Line.startsWith(tok::kw_extern) && Next && Next->isStringLiteral() && |
| NextNext && NextNext->is(tok::l_brace); |
| } |
| |
| /// \brief Tracks the indent level of \c AnnotatedLines across levels. |
| /// |
| /// \c nextLine must be called for each \c AnnotatedLine, after which \c |
| /// getIndent() will return the indent for the last line \c nextLine was called |
| /// with. |
| /// If the line is not formatted (and thus the indent does not change), calling |
| /// \c adjustToUnmodifiedLine after the call to \c nextLine will cause |
| /// subsequent lines on the same level to be indented at the same level as the |
| /// given line. |
| class LevelIndentTracker { |
| public: |
| LevelIndentTracker(const FormatStyle &Style, |
| const AdditionalKeywords &Keywords, unsigned StartLevel, |
| int AdditionalIndent) |
| : Style(Style), Keywords(Keywords), AdditionalIndent(AdditionalIndent) { |
| for (unsigned i = 0; i != StartLevel; ++i) |
| IndentForLevel.push_back(Style.IndentWidth * i + AdditionalIndent); |
| } |
| |
| /// \brief Returns the indent for the current line. |
| unsigned getIndent() const { return Indent; } |
| |
| /// \brief Update the indent state given that \p Line is going to be formatted |
| /// next. |
| void nextLine(const AnnotatedLine &Line) { |
| Offset = getIndentOffset(*Line.First); |
| // Update the indent level cache size so that we can rely on it |
| // having the right size in adjustToUnmodifiedline. |
| while (IndentForLevel.size() <= Line.Level) |
| IndentForLevel.push_back(-1); |
| if (Line.InPPDirective) { |
| Indent = Line.Level * Style.IndentWidth + AdditionalIndent; |
| } else { |
| IndentForLevel.resize(Line.Level + 1); |
| Indent = getIndent(IndentForLevel, Line.Level); |
| } |
| if (static_cast<int>(Indent) + Offset >= 0) |
| Indent += Offset; |
| } |
| |
| /// \brief Update the level indent to adapt to the given \p Line. |
| /// |
| /// When a line is not formatted, we move the subsequent lines on the same |
| /// level to the same indent. |
| /// Note that \c nextLine must have been called before this method. |
| void adjustToUnmodifiedLine(const AnnotatedLine &Line) { |
| unsigned LevelIndent = Line.First->OriginalColumn; |
| if (static_cast<int>(LevelIndent) - Offset >= 0) |
| LevelIndent -= Offset; |
| if ((!Line.First->is(tok::comment) || IndentForLevel[Line.Level] == -1) && |
| !Line.InPPDirective) |
| IndentForLevel[Line.Level] = LevelIndent; |
| } |
| |
| private: |
| /// \brief Get the offset of the line relatively to the level. |
| /// |
| /// For example, 'public:' labels in classes are offset by 1 or 2 |
| /// characters to the left from their level. |
| int getIndentOffset(const FormatToken &RootToken) { |
| if (Style.Language == FormatStyle::LK_Java || |
| Style.Language == FormatStyle::LK_JavaScript) |
| return 0; |
| if (RootToken.isAccessSpecifier(false) || |
| RootToken.isObjCAccessSpecifier() || |
| (RootToken.isOneOf(Keywords.kw_signals, Keywords.kw_qsignals) && |
| RootToken.Next && RootToken.Next->is(tok::colon))) |
| return Style.AccessModifierOffset; |
| return 0; |
| } |
| |
| /// \brief Get the indent of \p Level from \p IndentForLevel. |
| /// |
| /// \p IndentForLevel must contain the indent for the level \c l |
| /// at \p IndentForLevel[l], or a value < 0 if the indent for |
| /// that level is unknown. |
| unsigned getIndent(ArrayRef<int> IndentForLevel, unsigned Level) { |
| if (IndentForLevel[Level] != -1) |
| return IndentForLevel[Level]; |
| if (Level == 0) |
| return 0; |
| return getIndent(IndentForLevel, Level - 1) + Style.IndentWidth; |
| } |
| |
| const FormatStyle &Style; |
| const AdditionalKeywords &Keywords; |
| const unsigned AdditionalIndent; |
| |
| /// \brief The indent in characters for each level. |
| std::vector<int> IndentForLevel; |
| |
| /// \brief Offset of the current line relative to the indent level. |
| /// |
| /// For example, the 'public' keywords is often indented with a negative |
| /// offset. |
| int Offset = 0; |
| |
| /// \brief The current line's indent. |
| unsigned Indent = 0; |
| }; |
| |
| class LineJoiner { |
| public: |
| LineJoiner(const FormatStyle &Style, const AdditionalKeywords &Keywords, |
| const SmallVectorImpl<AnnotatedLine *> &Lines) |
| : Style(Style), Keywords(Keywords), End(Lines.end()), |
| Next(Lines.begin()) {} |
| |
| /// \brief Returns the next line, merging multiple lines into one if possible. |
| const AnnotatedLine *getNextMergedLine(bool DryRun, |
| LevelIndentTracker &IndentTracker) { |
| if (Next == End) |
| return nullptr; |
| const AnnotatedLine *Current = *Next; |
| IndentTracker.nextLine(*Current); |
| unsigned MergedLines = |
| tryFitMultipleLinesInOne(IndentTracker.getIndent(), Next, End); |
| if (MergedLines > 0 && Style.ColumnLimit == 0) |
| // Disallow line merging if there is a break at the start of one of the |
| // input lines. |
| for (unsigned i = 0; i < MergedLines; ++i) |
| if (Next[i + 1]->First->NewlinesBefore > 0) |
| MergedLines = 0; |
| if (!DryRun) |
| for (unsigned i = 0; i < MergedLines; ++i) |
| join(*Next[i], *Next[i + 1]); |
| Next = Next + MergedLines + 1; |
| return Current; |
| } |
| |
| private: |
| /// \brief Calculates how many lines can be merged into 1 starting at \p I. |
| unsigned |
| tryFitMultipleLinesInOne(unsigned Indent, |
| SmallVectorImpl<AnnotatedLine *>::const_iterator I, |
| SmallVectorImpl<AnnotatedLine *>::const_iterator E) { |
| // Can't join the last line with anything. |
| if (I + 1 == E) |
| return 0; |
| // We can never merge stuff if there are trailing line comments. |
| const AnnotatedLine *TheLine = *I; |
| if (TheLine->Last->is(TT_LineComment)) |
| return 0; |
| if (I[1]->Type == LT_Invalid || I[1]->First->MustBreakBefore) |
| return 0; |
| if (TheLine->InPPDirective && |
| (!I[1]->InPPDirective || I[1]->First->HasUnescapedNewline)) |
| return 0; |
| |
| if (Style.ColumnLimit > 0 && Indent > Style.ColumnLimit) |
| return 0; |
| |
| unsigned Limit = |
| Style.ColumnLimit == 0 ? UINT_MAX : Style.ColumnLimit - Indent; |
| // If we already exceed the column limit, we set 'Limit' to 0. The different |
| // tryMerge..() functions can then decide whether to still do merging. |
| Limit = TheLine->Last->TotalLength > Limit |
| ? 0 |
| : Limit - TheLine->Last->TotalLength; |
| |
| // FIXME: TheLine->Level != 0 might or might not be the right check to do. |
| // If necessary, change to something smarter. |
| bool MergeShortFunctions = |
| Style.AllowShortFunctionsOnASingleLine == FormatStyle::SFS_All || |
| (Style.AllowShortFunctionsOnASingleLine >= FormatStyle::SFS_Empty && |
| I[1]->First->is(tok::r_brace)) || |
| (Style.AllowShortFunctionsOnASingleLine == FormatStyle::SFS_Inline && |
| TheLine->Level != 0); |
| |
| if (TheLine->Last->is(TT_FunctionLBrace) && |
| TheLine->First != TheLine->Last) { |
| return MergeShortFunctions ? tryMergeSimpleBlock(I, E, Limit) : 0; |
| } |
| if (TheLine->Last->is(tok::l_brace)) { |
| return !Style.BraceWrapping.AfterFunction |
| ? tryMergeSimpleBlock(I, E, Limit) |
| : 0; |
| } |
| if (I[1]->First->is(TT_FunctionLBrace) && |
| Style.BraceWrapping.AfterFunction) { |
| if (I[1]->Last->is(TT_LineComment)) |
| return 0; |
| |
| // Check for Limit <= 2 to account for the " {". |
| if (Limit <= 2 || (Style.ColumnLimit == 0 && containsMustBreak(TheLine))) |
| return 0; |
| Limit -= 2; |
| |
| unsigned MergedLines = 0; |
| if (MergeShortFunctions) { |
| MergedLines = tryMergeSimpleBlock(I + 1, E, Limit); |
| // If we managed to merge the block, count the function header, which is |
| // on a separate line. |
| if (MergedLines > 0) |
| ++MergedLines; |
| } |
| return MergedLines; |
| } |
| if (TheLine->First->is(tok::kw_if)) { |
| return Style.AllowShortIfStatementsOnASingleLine |
| ? tryMergeSimpleControlStatement(I, E, Limit) |
| : 0; |
| } |
| if (TheLine->First->isOneOf(tok::kw_for, tok::kw_while)) { |
| return Style.AllowShortLoopsOnASingleLine |
| ? tryMergeSimpleControlStatement(I, E, Limit) |
| : 0; |
| } |
| if (TheLine->First->isOneOf(tok::kw_case, tok::kw_default)) { |
| return Style.AllowShortCaseLabelsOnASingleLine |
| ? tryMergeShortCaseLabels(I, E, Limit) |
| : 0; |
| } |
| if (TheLine->InPPDirective && |
| (TheLine->First->HasUnescapedNewline || TheLine->First->IsFirst)) { |
| return tryMergeSimplePPDirective(I, E, Limit); |
| } |
| return 0; |
| } |
| |
| unsigned |
| tryMergeSimplePPDirective(SmallVectorImpl<AnnotatedLine *>::const_iterator I, |
| SmallVectorImpl<AnnotatedLine *>::const_iterator E, |
| unsigned Limit) { |
| if (Limit == 0) |
| return 0; |
| if (I + 2 != E && I[2]->InPPDirective && !I[2]->First->HasUnescapedNewline) |
| return 0; |
| if (1 + I[1]->Last->TotalLength > Limit) |
| return 0; |
| return 1; |
| } |
| |
| unsigned tryMergeSimpleControlStatement( |
| SmallVectorImpl<AnnotatedLine *>::const_iterator I, |
| SmallVectorImpl<AnnotatedLine *>::const_iterator E, unsigned Limit) { |
| if (Limit == 0) |
| return 0; |
| if (Style.BraceWrapping.AfterControlStatement && |
| (I[1]->First->is(tok::l_brace) && !Style.AllowShortBlocksOnASingleLine)) |
| return 0; |
| if (I[1]->InPPDirective != (*I)->InPPDirective || |
| (I[1]->InPPDirective && I[1]->First->HasUnescapedNewline)) |
| return 0; |
| Limit = limitConsideringMacros(I + 1, E, Limit); |
| AnnotatedLine &Line = **I; |
| if (Line.Last->isNot(tok::r_paren)) |
| return 0; |
| if (1 + I[1]->Last->TotalLength > Limit) |
| return 0; |
| if (I[1]->First->isOneOf(tok::semi, tok::kw_if, tok::kw_for, tok::kw_while, |
| TT_LineComment)) |
| return 0; |
| // Only inline simple if's (no nested if or else). |
| if (I + 2 != E && Line.startsWith(tok::kw_if) && |
| I[2]->First->is(tok::kw_else)) |
| return 0; |
| return 1; |
| } |
| |
| unsigned |
| tryMergeShortCaseLabels(SmallVectorImpl<AnnotatedLine *>::const_iterator I, |
| SmallVectorImpl<AnnotatedLine *>::const_iterator E, |
| unsigned Limit) { |
| if (Limit == 0 || I + 1 == E || |
| I[1]->First->isOneOf(tok::kw_case, tok::kw_default)) |
| return 0; |
| unsigned NumStmts = 0; |
| unsigned Length = 0; |
| bool InPPDirective = I[0]->InPPDirective; |
| for (; NumStmts < 3; ++NumStmts) { |
| if (I + 1 + NumStmts == E) |
| break; |
| const AnnotatedLine *Line = I[1 + NumStmts]; |
| if (Line->InPPDirective != InPPDirective) |
| break; |
| if (Line->First->isOneOf(tok::kw_case, tok::kw_default, tok::r_brace)) |
| break; |
| if (Line->First->isOneOf(tok::kw_if, tok::kw_for, tok::kw_switch, |
| tok::kw_while, tok::comment) || |
| Line->Last->is(tok::comment)) |
| return 0; |
| Length += I[1 + NumStmts]->Last->TotalLength + 1; // 1 for the space. |
| } |
| if (NumStmts == 0 || NumStmts == 3 || Length > Limit) |
| return 0; |
| return NumStmts; |
| } |
| |
| unsigned |
| tryMergeSimpleBlock(SmallVectorImpl<AnnotatedLine *>::const_iterator I, |
| SmallVectorImpl<AnnotatedLine *>::const_iterator E, |
| unsigned Limit) { |
| AnnotatedLine &Line = **I; |
| |
| // Don't merge ObjC @ keywords and methods. |
| // FIXME: If an option to allow short exception handling clauses on a single |
| // line is added, change this to not return for @try and friends. |
| if (Style.Language != FormatStyle::LK_Java && |
| Line.First->isOneOf(tok::at, tok::minus, tok::plus)) |
| return 0; |
| |
| // Check that the current line allows merging. This depends on whether we |
| // are in a control flow statements as well as several style flags. |
| if (Line.First->isOneOf(tok::kw_else, tok::kw_case) || |
| (Line.First->Next && Line.First->Next->is(tok::kw_else))) |
| return 0; |
| if (Line.First->isOneOf(tok::kw_if, tok::kw_while, tok::kw_do, tok::kw_try, |
| tok::kw___try, tok::kw_catch, tok::kw___finally, |
| tok::kw_for, tok::r_brace, Keywords.kw___except)) { |
| if (!Style.AllowShortBlocksOnASingleLine) |
| return 0; |
| if (!Style.AllowShortIfStatementsOnASingleLine && |
| Line.startsWith(tok::kw_if)) |
| return 0; |
| if (!Style.AllowShortLoopsOnASingleLine && |
| Line.First->isOneOf(tok::kw_while, tok::kw_do, tok::kw_for)) |
| return 0; |
| // FIXME: Consider an option to allow short exception handling clauses on |
| // a single line. |
| // FIXME: This isn't covered by tests. |
| // FIXME: For catch, __except, __finally the first token on the line |
| // is '}', so this isn't correct here. |
| if (Line.First->isOneOf(tok::kw_try, tok::kw___try, tok::kw_catch, |
| Keywords.kw___except, tok::kw___finally)) |
| return 0; |
| } |
| |
| FormatToken *Tok = I[1]->First; |
| if (Tok->is(tok::r_brace) && !Tok->MustBreakBefore && |
| (Tok->getNextNonComment() == nullptr || |
| Tok->getNextNonComment()->is(tok::semi))) { |
| // We merge empty blocks even if the line exceeds the column limit. |
| Tok->SpacesRequiredBefore = 0; |
| Tok->CanBreakBefore = true; |
| return 1; |
| } else if (Limit != 0 && !Line.startsWith(tok::kw_namespace) && |
| !startsExternCBlock(Line)) { |
| // We don't merge short records. |
| if (Line.First->isOneOf(tok::kw_class, tok::kw_union, tok::kw_struct, |
| Keywords.kw_interface)) |
| return 0; |
| |
| // Check that we still have three lines and they fit into the limit. |
| if (I + 2 == E || I[2]->Type == LT_Invalid) |
| return 0; |
| Limit = limitConsideringMacros(I + 2, E, Limit); |
| |
| if (!nextTwoLinesFitInto(I, Limit)) |
| return 0; |
| |
| // Second, check that the next line does not contain any braces - if it |
| // does, readability declines when putting it into a single line. |
| if (I[1]->Last->is(TT_LineComment)) |
| return 0; |
| do { |
| if (Tok->is(tok::l_brace) && Tok->BlockKind != BK_BracedInit) |
| return 0; |
| Tok = Tok->Next; |
| } while (Tok); |
| |
| // Last, check that the third line starts with a closing brace. |
| Tok = I[2]->First; |
| if (Tok->isNot(tok::r_brace)) |
| return 0; |
| |
| // Don't merge "if (a) { .. } else {". |
| if (Tok->Next && Tok->Next->is(tok::kw_else)) |
| return 0; |
| |
| return 2; |
| } |
| return 0; |
| } |
| |
| /// Returns the modified column limit for \p I if it is inside a macro and |
| /// needs a trailing '\'. |
| unsigned |
| limitConsideringMacros(SmallVectorImpl<AnnotatedLine *>::const_iterator I, |
| SmallVectorImpl<AnnotatedLine *>::const_iterator E, |
| unsigned Limit) { |
| if (I[0]->InPPDirective && I + 1 != E && |
| !I[1]->First->HasUnescapedNewline && !I[1]->First->is(tok::eof)) { |
| return Limit < 2 ? 0 : Limit - 2; |
| } |
| return Limit; |
| } |
| |
| bool nextTwoLinesFitInto(SmallVectorImpl<AnnotatedLine *>::const_iterator I, |
| unsigned Limit) { |
| if (I[1]->First->MustBreakBefore || I[2]->First->MustBreakBefore) |
| return false; |
| return 1 + I[1]->Last->TotalLength + 1 + I[2]->Last->TotalLength <= Limit; |
| } |
| |
| bool containsMustBreak(const AnnotatedLine *Line) { |
| for (const FormatToken *Tok = Line->First; Tok; Tok = Tok->Next) { |
| if (Tok->MustBreakBefore) |
| return true; |
| } |
| return false; |
| } |
| |
| void join(AnnotatedLine &A, const AnnotatedLine &B) { |
| assert(!A.Last->Next); |
| assert(!B.First->Previous); |
| if (B.Affected) |
| A.Affected = true; |
| A.Last->Next = B.First; |
| B.First->Previous = A.Last; |
| B.First->CanBreakBefore = true; |
| unsigned LengthA = A.Last->TotalLength + B.First->SpacesRequiredBefore; |
| for (FormatToken *Tok = B.First; Tok; Tok = Tok->Next) { |
| Tok->TotalLength += LengthA; |
| A.Last = Tok; |
| } |
| } |
| |
| const FormatStyle &Style; |
| const AdditionalKeywords &Keywords; |
| const SmallVectorImpl<AnnotatedLine *>::const_iterator End; |
| |
| SmallVectorImpl<AnnotatedLine *>::const_iterator Next; |
| }; |
| |
| static void markFinalized(FormatToken *Tok) { |
| for (; Tok; Tok = Tok->Next) { |
| Tok->Finalized = true; |
| for (AnnotatedLine *Child : Tok->Children) |
| markFinalized(Child->First); |
| } |
| } |
| |
| #ifndef NDEBUG |
| static void printLineState(const LineState &State) { |
| llvm::dbgs() << "State: "; |
| for (const ParenState &P : State.Stack) { |
| llvm::dbgs() << P.Indent << "|" << P.LastSpace << "|" << P.NestedBlockIndent |
| << " "; |
| } |
| llvm::dbgs() << State.NextToken->TokenText << "\n"; |
| } |
| #endif |
| |
| /// \brief Base class for classes that format one \c AnnotatedLine. |
| class LineFormatter { |
| public: |
| LineFormatter(ContinuationIndenter *Indenter, WhitespaceManager *Whitespaces, |
| const FormatStyle &Style, |
| UnwrappedLineFormatter *BlockFormatter) |
| : Indenter(Indenter), Whitespaces(Whitespaces), Style(Style), |
| BlockFormatter(BlockFormatter) {} |
| virtual ~LineFormatter() {} |
| |
| /// \brief Formats an \c AnnotatedLine and returns the penalty. |
| /// |
| /// If \p DryRun is \c false, directly applies the changes. |
| virtual unsigned formatLine(const AnnotatedLine &Line, unsigned FirstIndent, |
| bool DryRun) = 0; |
| |
| protected: |
| /// \brief If the \p State's next token is an r_brace closing a nested block, |
| /// format the nested block before it. |
| /// |
| /// Returns \c true if all children could be placed successfully and adapts |
| /// \p Penalty as well as \p State. If \p DryRun is false, also directly |
| /// creates changes using \c Whitespaces. |
| /// |
| /// The crucial idea here is that children always get formatted upon |
| /// encountering the closing brace right after the nested block. Now, if we |
| /// are currently trying to keep the "}" on the same line (i.e. \p NewLine is |
| /// \c false), the entire block has to be kept on the same line (which is only |
| /// possible if it fits on the line, only contains a single statement, etc. |
| /// |
| /// If \p NewLine is true, we format the nested block on separate lines, i.e. |
| /// break after the "{", format all lines with correct indentation and the put |
| /// the closing "}" on yet another new line. |
| /// |
| /// This enables us to keep the simple structure of the |
| /// \c UnwrappedLineFormatter, where we only have two options for each token: |
| /// break or don't break. |
| bool formatChildren(LineState &State, bool NewLine, bool DryRun, |
| unsigned &Penalty) { |
| const FormatToken *LBrace = State.NextToken->getPreviousNonComment(); |
| FormatToken &Previous = *State.NextToken->Previous; |
| if (!LBrace || LBrace->isNot(tok::l_brace) || |
| LBrace->BlockKind != BK_Block || Previous.Children.size() == 0) |
| // The previous token does not open a block. Nothing to do. We don't |
| // assert so that we can simply call this function for all tokens. |
| return true; |
| |
| if (NewLine) { |
| int AdditionalIndent = State.Stack.back().Indent - |
| Previous.Children[0]->Level * Style.IndentWidth; |
| |
| Penalty += |
| BlockFormatter->format(Previous.Children, DryRun, AdditionalIndent, |
| /*FixBadIndentation=*/true); |
| return true; |
| } |
| |
| if (Previous.Children[0]->First->MustBreakBefore) |
| return false; |
| |
| // Cannot merge multiple statements into a single line. |
| if (Previous.Children.size() > 1) |
| return false; |
| |
| // Cannot merge into one line if this line ends on a comment. |
| if (Previous.is(tok::comment)) |
| return false; |
| |
| // We can't put the closing "}" on a line with a trailing comment. |
| if (Previous.Children[0]->Last->isTrailingComment()) |
| return false; |
| |
| // If the child line exceeds the column limit, we wouldn't want to merge it. |
| // We add +2 for the trailing " }". |
| if (Style.ColumnLimit > 0 && |
| Previous.Children[0]->Last->TotalLength + State.Column + 2 > |
| Style.ColumnLimit) |
| return false; |
| |
| if (!DryRun) { |
| Whitespaces->replaceWhitespace( |
| *Previous.Children[0]->First, |
| /*Newlines=*/0, /*IndentLevel=*/0, /*Spaces=*/1, |
| /*StartOfTokenColumn=*/State.Column, State.Line->InPPDirective); |
| } |
| Penalty += formatLine(*Previous.Children[0], State.Column + 1, DryRun); |
| |
| State.Column += 1 + Previous.Children[0]->Last->TotalLength; |
| return true; |
| } |
| |
| ContinuationIndenter *Indenter; |
| |
| private: |
| WhitespaceManager *Whitespaces; |
| const FormatStyle &Style; |
| UnwrappedLineFormatter *BlockFormatter; |
| }; |
| |
| /// \brief Formatter that keeps the existing line breaks. |
| class NoColumnLimitLineFormatter : public LineFormatter { |
| public: |
| NoColumnLimitLineFormatter(ContinuationIndenter *Indenter, |
| WhitespaceManager *Whitespaces, |
| const FormatStyle &Style, |
| UnwrappedLineFormatter *BlockFormatter) |
| : LineFormatter(Indenter, Whitespaces, Style, BlockFormatter) {} |
| |
| /// \brief Formats the line, simply keeping all of the input's line breaking |
| /// decisions. |
| unsigned formatLine(const AnnotatedLine &Line, unsigned FirstIndent, |
| bool DryRun) override { |
| assert(!DryRun); |
| LineState State = |
| Indenter->getInitialState(FirstIndent, &Line, /*DryRun=*/false); |
| while (State.NextToken) { |
| bool Newline = |
| Indenter->mustBreak(State) || |
| (Indenter->canBreak(State) && State.NextToken->NewlinesBefore > 0); |
| unsigned Penalty = 0; |
| formatChildren(State, Newline, /*DryRun=*/false, Penalty); |
| Indenter->addTokenToState(State, Newline, /*DryRun=*/false); |
| } |
| return 0; |
| } |
| }; |
| |
| /// \brief Formatter that puts all tokens into a single line without breaks. |
| class NoLineBreakFormatter : public LineFormatter { |
| public: |
| NoLineBreakFormatter(ContinuationIndenter *Indenter, |
| WhitespaceManager *Whitespaces, const FormatStyle &Style, |
| UnwrappedLineFormatter *BlockFormatter) |
| : LineFormatter(Indenter, Whitespaces, Style, BlockFormatter) {} |
| |
| /// \brief Puts all tokens into a single line. |
| unsigned formatLine(const AnnotatedLine &Line, unsigned FirstIndent, |
| bool DryRun) override { |
| unsigned Penalty = 0; |
| LineState State = Indenter->getInitialState(FirstIndent, &Line, DryRun); |
| while (State.NextToken) { |
| formatChildren(State, /*Newline=*/false, DryRun, Penalty); |
| Indenter->addTokenToState(State, /*Newline=*/false, DryRun); |
| } |
| return Penalty; |
| } |
| }; |
| |
| /// \brief Finds the best way to break lines. |
| class OptimizingLineFormatter : public LineFormatter { |
| public: |
| OptimizingLineFormatter(ContinuationIndenter *Indenter, |
| WhitespaceManager *Whitespaces, |
| const FormatStyle &Style, |
| UnwrappedLineFormatter *BlockFormatter) |
| : LineFormatter(Indenter, Whitespaces, Style, BlockFormatter) {} |
| |
| /// \brief Formats the line by finding the best line breaks with line lengths |
| /// below the column limit. |
| unsigned formatLine(const AnnotatedLine &Line, unsigned FirstIndent, |
| bool DryRun) override { |
| LineState State = Indenter->getInitialState(FirstIndent, &Line, DryRun); |
| |
| // If the ObjC method declaration does not fit on a line, we should format |
| // it with one arg per line. |
| if (State.Line->Type == LT_ObjCMethodDecl) |
| State.Stack.back().BreakBeforeParameter = true; |
| |
| // Find best solution in solution space. |
| return analyzeSolutionSpace(State, DryRun); |
| } |
| |
| private: |
| struct CompareLineStatePointers { |
| bool operator()(LineState *obj1, LineState *obj2) const { |
| return *obj1 < *obj2; |
| } |
| }; |
| |
| /// \brief A pair of <penalty, count> that is used to prioritize the BFS on. |
| /// |
| /// In case of equal penalties, we want to prefer states that were inserted |
| /// first. During state generation we make sure that we insert states first |
| /// that break the line as late as possible. |
| typedef std::pair<unsigned, unsigned> OrderedPenalty; |
| |
| /// \brief An edge in the solution space from \c Previous->State to \c State, |
| /// inserting a newline dependent on the \c NewLine. |
| struct StateNode { |
| StateNode(const LineState &State, bool NewLine, StateNode *Previous) |
| : State(State), NewLine(NewLine), Previous(Previous) {} |
| LineState State; |
| bool NewLine; |
| StateNode *Previous; |
| }; |
| |
| /// \brief An item in the prioritized BFS search queue. The \c StateNode's |
| /// \c State has the given \c OrderedPenalty. |
| typedef std::pair<OrderedPenalty, StateNode *> QueueItem; |
| |
| /// \brief The BFS queue type. |
| typedef std::priority_queue<QueueItem, std::vector<QueueItem>, |
| std::greater<QueueItem>> QueueType; |
| |
| /// \brief Analyze the entire solution space starting from \p InitialState. |
| /// |
| /// This implements a variant of Dijkstra's algorithm on the graph that spans |
| /// the solution space (\c LineStates are the nodes). The algorithm tries to |
| /// find the shortest path (the one with lowest penalty) from \p InitialState |
| /// to a state where all tokens are placed. Returns the penalty. |
| /// |
| /// If \p DryRun is \c false, directly applies the changes. |
| unsigned analyzeSolutionSpace(LineState &InitialState, bool DryRun) { |
| std::set<LineState *, CompareLineStatePointers> Seen; |
| |
| // Increasing count of \c StateNode items we have created. This is used to |
| // create a deterministic order independent of the container. |
| unsigned Count = 0; |
| QueueType Queue; |
| |
| // Insert start element into queue. |
| StateNode *Node = |
| new (Allocator.Allocate()) StateNode(InitialState, false, nullptr); |
| Queue.push(QueueItem(OrderedPenalty(0, Count), Node)); |
| ++Count; |
| |
| unsigned Penalty = 0; |
| |
| // While not empty, take first element and follow edges. |
| while (!Queue.empty()) { |
| Penalty = Queue.top().first.first; |
| StateNode *Node = Queue.top().second; |
| if (!Node->State.NextToken) { |
| DEBUG(llvm::dbgs() << "\n---\nPenalty for line: " << Penalty << "\n"); |
| break; |
| } |
| Queue.pop(); |
| |
| // Cut off the analysis of certain solutions if the analysis gets too |
| // complex. See description of IgnoreStackForComparison. |
| if (Count > 50000) |
| Node->State.IgnoreStackForComparison = true; |
| |
| if (!Seen.insert(&Node->State).second) |
| // State already examined with lower penalty. |
| continue; |
| |
| FormatDecision LastFormat = Node->State.NextToken->Decision; |
| if (LastFormat == FD_Unformatted || LastFormat == FD_Continue) |
| addNextStateToQueue(Penalty, Node, /*NewLine=*/false, &Count, &Queue); |
| if (LastFormat == FD_Unformatted || LastFormat == FD_Break) |
| addNextStateToQueue(Penalty, Node, /*NewLine=*/true, &Count, &Queue); |
| } |
| |
| if (Queue.empty()) { |
| // We were unable to find a solution, do nothing. |
| // FIXME: Add diagnostic? |
| DEBUG(llvm::dbgs() << "Could not find a solution.\n"); |
| return 0; |
| } |
| |
| // Reconstruct the solution. |
| if (!DryRun) |
| reconstructPath(InitialState, Queue.top().second); |
| |
| DEBUG(llvm::dbgs() << "Total number of analyzed states: " << Count << "\n"); |
| DEBUG(llvm::dbgs() << "---\n"); |
| |
| return Penalty; |
| } |
| |
| /// \brief Add the following state to the analysis queue \c Queue. |
| /// |
| /// Assume the current state is \p PreviousNode and has been reached with a |
| /// penalty of \p Penalty. Insert a line break if \p NewLine is \c true. |
| void addNextStateToQueue(unsigned Penalty, StateNode *PreviousNode, |
| bool NewLine, unsigned *Count, QueueType *Queue) { |
| if (NewLine && !Indenter->canBreak(PreviousNode->State)) |
| return; |
| if (!NewLine && Indenter->mustBreak(PreviousNode->State)) |
| return; |
| |
| StateNode *Node = new (Allocator.Allocate()) |
| StateNode(PreviousNode->State, NewLine, PreviousNode); |
| if (!formatChildren(Node->State, NewLine, /*DryRun=*/true, Penalty)) |
| return; |
| |
| Penalty += Indenter->addTokenToState(Node->State, NewLine, true); |
| |
| Queue->push(QueueItem(OrderedPenalty(Penalty, *Count), Node)); |
| ++(*Count); |
| } |
| |
| /// \brief Applies the best formatting by reconstructing the path in the |
| /// solution space that leads to \c Best. |
| void reconstructPath(LineState &State, StateNode *Best) { |
| std::deque<StateNode *> Path; |
| // We do not need a break before the initial token. |
| while (Best->Previous) { |
| Path.push_front(Best); |
| Best = Best->Previous; |
| } |
| for (std::deque<StateNode *>::iterator I = Path.begin(), E = Path.end(); |
| I != E; ++I) { |
| unsigned Penalty = 0; |
| formatChildren(State, (*I)->NewLine, /*DryRun=*/false, Penalty); |
| Penalty += Indenter->addTokenToState(State, (*I)->NewLine, false); |
| |
| DEBUG({ |
| printLineState((*I)->Previous->State); |
| if ((*I)->NewLine) { |
| llvm::dbgs() << "Penalty for placing " |
| << (*I)->Previous->State.NextToken->Tok.getName() << ": " |
| << Penalty << "\n"; |
| } |
| }); |
| } |
| } |
| |
| llvm::SpecificBumpPtrAllocator<StateNode> Allocator; |
| }; |
| |
| } // anonymous namespace |
| |
| unsigned |
| UnwrappedLineFormatter::format(const SmallVectorImpl<AnnotatedLine *> &Lines, |
| bool DryRun, int AdditionalIndent, |
| bool FixBadIndentation) { |
| LineJoiner Joiner(Style, Keywords, Lines); |
| |
| // Try to look up already computed penalty in DryRun-mode. |
| std::pair<const SmallVectorImpl<AnnotatedLine *> *, unsigned> CacheKey( |
| &Lines, AdditionalIndent); |
| auto CacheIt = PenaltyCache.find(CacheKey); |
| if (DryRun && CacheIt != PenaltyCache.end()) |
| return CacheIt->second; |
| |
| assert(!Lines.empty()); |
| unsigned Penalty = 0; |
| LevelIndentTracker IndentTracker(Style, Keywords, Lines[0]->Level, |
| AdditionalIndent); |
| const AnnotatedLine *PreviousLine = nullptr; |
| const AnnotatedLine *NextLine = nullptr; |
| |
| // The minimum level of consecutive lines that have been formatted. |
| unsigned RangeMinLevel = UINT_MAX; |
| |
| for (const AnnotatedLine *Line = |
| Joiner.getNextMergedLine(DryRun, IndentTracker); |
| Line; Line = NextLine) { |
| const AnnotatedLine &TheLine = *Line; |
| unsigned Indent = IndentTracker.getIndent(); |
| |
| // We continue formatting unchanged lines to adjust their indent, e.g. if a |
| // scope was added. However, we need to carefully stop doing this when we |
| // exit the scope of affected lines to prevent indenting a the entire |
| // remaining file if it currently missing a closing brace. |
| bool ContinueFormatting = |
| TheLine.Level > RangeMinLevel || |
| (TheLine.Level == RangeMinLevel && !TheLine.startsWith(tok::r_brace)); |
| |
| bool FixIndentation = (FixBadIndentation || ContinueFormatting) && |
| Indent != TheLine.First->OriginalColumn; |
| bool ShouldFormat = TheLine.Affected || FixIndentation; |
| // We cannot format this line; if the reason is that the line had a |
| // parsing error, remember that. |
| if (ShouldFormat && TheLine.Type == LT_Invalid && IncompleteFormat) |
| *IncompleteFormat = true; |
| |
| if (ShouldFormat && TheLine.Type != LT_Invalid) { |
| if (!DryRun) |
| formatFirstToken(*TheLine.First, PreviousLine, TheLine.Level, Indent, |
| TheLine.InPPDirective); |
| |
| NextLine = Joiner.getNextMergedLine(DryRun, IndentTracker); |
| unsigned ColumnLimit = getColumnLimit(TheLine.InPPDirective, NextLine); |
| bool FitsIntoOneLine = |
| TheLine.Last->TotalLength + Indent <= ColumnLimit || |
| (TheLine.Type == LT_ImportStatement && |
| (Style.Language != FormatStyle::LK_JavaScript || |
| !Style.JavaScriptWrapImports)); |
| |
| if (Style.ColumnLimit == 0) |
| NoColumnLimitLineFormatter(Indenter, Whitespaces, Style, this) |
| .formatLine(TheLine, Indent, DryRun); |
| else if (FitsIntoOneLine) |
| Penalty += NoLineBreakFormatter(Indenter, Whitespaces, Style, this) |
| .formatLine(TheLine, Indent, DryRun); |
| else |
| Penalty += OptimizingLineFormatter(Indenter, Whitespaces, Style, this) |
| .formatLine(TheLine, Indent, DryRun); |
| RangeMinLevel = std::min(RangeMinLevel, TheLine.Level); |
| } else { |
| // If no token in the current line is affected, we still need to format |
| // affected children. |
| if (TheLine.ChildrenAffected) |
| for (const FormatToken *Tok = TheLine.First; Tok; Tok = Tok->Next) |
| if (!Tok->Children.empty()) |
| format(Tok->Children, DryRun); |
| |
| // Adapt following lines on the current indent level to the same level |
| // unless the current \c AnnotatedLine is not at the beginning of a line. |
| bool StartsNewLine = |
| TheLine.First->NewlinesBefore > 0 || TheLine.First->IsFirst; |
| if (StartsNewLine) |
| IndentTracker.adjustToUnmodifiedLine(TheLine); |
| if (!DryRun) { |
| bool ReformatLeadingWhitespace = |
| StartsNewLine && ((PreviousLine && PreviousLine->Affected) || |
| TheLine.LeadingEmptyLinesAffected); |
| // Format the first token. |
| if (ReformatLeadingWhitespace) |
| formatFirstToken(*TheLine.First, PreviousLine, TheLine.Level, |
| TheLine.First->OriginalColumn, |
| TheLine.InPPDirective); |
| else |
| Whitespaces->addUntouchableToken(*TheLine.First, |
| TheLine.InPPDirective); |
| |
| // Notify the WhitespaceManager about the unchanged whitespace. |
| for (FormatToken *Tok = TheLine.First->Next; Tok; Tok = Tok->Next) |
| Whitespaces->addUntouchableToken(*Tok, TheLine.InPPDirective); |
| } |
| NextLine = Joiner.getNextMergedLine(DryRun, IndentTracker); |
| RangeMinLevel = UINT_MAX; |
| } |
| if (!DryRun) |
| markFinalized(TheLine.First); |
| PreviousLine = &TheLine; |
| } |
| PenaltyCache[CacheKey] = Penalty; |
| return Penalty; |
| } |
| |
| void UnwrappedLineFormatter::formatFirstToken(FormatToken &RootToken, |
| const AnnotatedLine *PreviousLine, |
| unsigned IndentLevel, |
| unsigned Indent, |
| bool InPPDirective) { |
| if (RootToken.is(tok::eof)) { |
| unsigned Newlines = std::min(RootToken.NewlinesBefore, 1u); |
| Whitespaces->replaceWhitespace(RootToken, Newlines, /*IndentLevel=*/0, |
| /*Spaces=*/0, /*TargetColumn=*/0); |
| return; |
| } |
| unsigned Newlines = |
| std::min(RootToken.NewlinesBefore, Style.MaxEmptyLinesToKeep + 1); |
| // Remove empty lines before "}" where applicable. |
| if (RootToken.is(tok::r_brace) && |
| (!RootToken.Next || |
| (RootToken.Next->is(tok::semi) && !RootToken.Next->Next))) |
| Newlines = std::min(Newlines, 1u); |
| if (Newlines == 0 && !RootToken.IsFirst) |
| Newlines = 1; |
| if (RootToken.IsFirst && !RootToken.HasUnescapedNewline) |
| Newlines = 0; |
| |
| // Remove empty lines after "{". |
| if (!Style.KeepEmptyLinesAtTheStartOfBlocks && PreviousLine && |
| PreviousLine->Last->is(tok::l_brace) && |
| PreviousLine->First->isNot(tok::kw_namespace) && |
| !startsExternCBlock(*PreviousLine)) |
| Newlines = 1; |
| |
| // Insert extra new line before access specifiers. |
| if (PreviousLine && PreviousLine->Last->isOneOf(tok::semi, tok::r_brace) && |
| RootToken.isAccessSpecifier() && RootToken.NewlinesBefore == 1) |
| ++Newlines; |
| |
| // Remove empty lines after access specifiers. |
| if (PreviousLine && PreviousLine->First->isAccessSpecifier() && |
| (!PreviousLine->InPPDirective || !RootToken.HasUnescapedNewline)) |
| Newlines = std::min(1u, Newlines); |
| |
| Whitespaces->replaceWhitespace(RootToken, Newlines, IndentLevel, Indent, |
| Indent, InPPDirective && |
| !RootToken.HasUnescapedNewline); |
| } |
| |
| unsigned |
| UnwrappedLineFormatter::getColumnLimit(bool InPPDirective, |
| const AnnotatedLine *NextLine) const { |
| // In preprocessor directives reserve two chars for trailing " \" if the |
| // next line continues the preprocessor directive. |
| bool ContinuesPPDirective = |
| InPPDirective && |
| // If there is no next line, this is likely a child line and the parent |
| // continues the preprocessor directive. |
| (!NextLine || |
| (NextLine->InPPDirective && |
| // If there is an unescaped newline between this line and the next, the |
| // next line starts a new preprocessor directive. |
| !NextLine->First->HasUnescapedNewline)); |
| return Style.ColumnLimit - (ContinuesPPDirective ? 2 : 0); |
| } |
| |
| } // namespace format |
| } // namespace clang |