r223936 - clang-format: Factor out UnwrappedLineFormatter into a separate file.
Daniel Jasper
djasper at google.com
Wed Dec 10 11:00:42 PST 2014
Author: djasper
Date: Wed Dec 10 13:00:42 2014
New Revision: 223936
URL: http://llvm.org/viewvc/llvm-project?rev=223936&view=rev
Log:
clang-format: Factor out UnwrappedLineFormatter into a separate file.
No functional changes intended.
Added:
cfe/trunk/lib/Format/UnwrappedLineFormatter.cpp
cfe/trunk/lib/Format/UnwrappedLineFormatter.h
Modified:
cfe/trunk/lib/Format/CMakeLists.txt
cfe/trunk/lib/Format/Format.cpp
Modified: cfe/trunk/lib/Format/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Format/CMakeLists.txt?rev=223936&r1=223935&r2=223936&view=diff
==============================================================================
--- cfe/trunk/lib/Format/CMakeLists.txt (original)
+++ cfe/trunk/lib/Format/CMakeLists.txt Wed Dec 10 13:00:42 2014
@@ -6,6 +6,7 @@ add_clang_library(clangFormat
Format.cpp
FormatToken.cpp
TokenAnnotator.cpp
+ UnwrappedLineFormatter.cpp
UnwrappedLineParser.cpp
WhitespaceManager.cpp
Modified: cfe/trunk/lib/Format/Format.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Format/Format.cpp?rev=223936&r1=223935&r2=223936&view=diff
==============================================================================
--- cfe/trunk/lib/Format/Format.cpp (original)
+++ cfe/trunk/lib/Format/Format.cpp Wed Dec 10 13:00:42 2014
@@ -15,6 +15,7 @@
#include "ContinuationIndenter.h"
#include "TokenAnnotator.h"
+#include "UnwrappedLineFormatter.h"
#include "UnwrappedLineParser.h"
#include "WhitespaceManager.h"
#include "clang/Basic/Diagnostic.h"
@@ -589,779 +590,6 @@ std::string configurationAsText(const Fo
namespace {
-bool startsExternCBlock(const AnnotatedLine &Line) {
- const FormatToken *Next = Line.First->getNextNonComment();
- const FormatToken *NextNext = Next ? Next->getNextNonComment() : nullptr;
- return Line.First->is(tok::kw_extern) && Next && Next->isStringLiteral() &&
- NextNext && NextNext->is(tok::l_brace);
-}
-
-class NoColumnLimitFormatter {
-public:
- NoColumnLimitFormatter(ContinuationIndenter *Indenter) : Indenter(Indenter) {}
-
- /// \brief Formats the line starting at \p State, simply keeping all of the
- /// input's line breaking decisions.
- void format(unsigned FirstIndent, const AnnotatedLine *Line) {
- LineState State =
- Indenter->getInitialState(FirstIndent, Line, /*DryRun=*/false);
- while (State.NextToken) {
- bool Newline =
- Indenter->mustBreak(State) ||
- (Indenter->canBreak(State) && State.NextToken->NewlinesBefore > 0);
- Indenter->addTokenToState(State, Newline, /*DryRun=*/false);
- }
- }
-
-private:
- ContinuationIndenter *Indenter;
-};
-
-class LineJoiner {
-public:
- LineJoiner(const FormatStyle &Style) : Style(Style) {}
-
- /// \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) {
- // We can never merge stuff if there are trailing line comments.
- const AnnotatedLine *TheLine = *I;
- if (TheLine->Last->is(TT_LineComment))
- 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;
-
- if (I + 1 == E || I[1]->Type == LT_Invalid || I[1]->First->MustBreakBefore)
- return 0;
-
- // 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.BreakBeforeBraces == FormatStyle::BS_Attach
- ? tryMergeSimpleBlock(I, E, Limit)
- : 0;
- }
- if (I[1]->First->is(TT_FunctionLBrace) &&
- Style.BreakBeforeBraces != FormatStyle::BS_Attach) {
- 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;
- }
-
-private:
- unsigned
- tryMergeSimplePPDirective(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
- SmallVectorImpl<AnnotatedLine *>::const_iterator E,
- unsigned Limit) {
- if (Limit == 0)
- return 0;
- if (!I[1]->InPPDirective || I[1]->First->HasUnescapedNewline)
- 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.BreakBeforeBraces == FormatStyle::BS_Allman ||
- Style.BreakBeforeBraces == FormatStyle::BS_GNU) &&
- (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.First->is(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))
- 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.
- 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))
- return 0;
- if (Line.First->isOneOf(tok::kw_if, tok::kw_while, tok::kw_do, tok::kw_try,
- tok::kw_catch, tok::kw_for, tok::r_brace)) {
- if (!Style.AllowShortBlocksOnASingleLine)
- return 0;
- if (!Style.AllowShortIfStatementsOnASingleLine &&
- Line.First->is(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.
- if (Line.First->isOneOf(tok::kw_try, tok::kw_catch))
- 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.First->isNot(tok::kw_namespace) &&
- !startsExternCBlock(Line)) {
- // We don't merge short records.
- if (Line.First->isOneOf(tok::kw_class, tok::kw_union, tok::kw_struct))
- 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;
-
- 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;
- }
-
- const FormatStyle &Style;
-};
-
-class UnwrappedLineFormatter {
-public:
- UnwrappedLineFormatter(ContinuationIndenter *Indenter,
- WhitespaceManager *Whitespaces,
- const FormatStyle &Style)
- : Indenter(Indenter), Whitespaces(Whitespaces), Style(Style),
- Joiner(Style) {}
-
- unsigned format(const SmallVectorImpl<AnnotatedLine *> &Lines, bool DryRun,
- int AdditionalIndent = 0, bool FixBadIndentation = false) {
- // 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;
- std::vector<int> IndentForLevel;
- for (unsigned i = 0, e = Lines[0]->Level; i != e; ++i)
- IndentForLevel.push_back(Style.IndentWidth * i + AdditionalIndent);
- const AnnotatedLine *PreviousLine = nullptr;
- for (SmallVectorImpl<AnnotatedLine *>::const_iterator I = Lines.begin(),
- E = Lines.end();
- I != E; ++I) {
- const AnnotatedLine &TheLine = **I;
- const FormatToken *FirstTok = TheLine.First;
- int Offset = getIndentOffset(*FirstTok);
-
- // Determine indent and try to merge multiple unwrapped lines.
- unsigned Indent;
- if (TheLine.InPPDirective) {
- Indent = TheLine.Level * Style.IndentWidth;
- } else {
- while (IndentForLevel.size() <= TheLine.Level)
- IndentForLevel.push_back(-1);
- IndentForLevel.resize(TheLine.Level + 1);
- Indent = getIndent(IndentForLevel, TheLine.Level);
- }
- unsigned LevelIndent = Indent;
- if (static_cast<int>(Indent) + Offset >= 0)
- Indent += Offset;
-
- // Merge multiple lines if possible.
- unsigned MergedLines = Joiner.tryFitMultipleLinesInOne(Indent, I, E);
- 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 (I[i + 1]->First->NewlinesBefore > 0)
- MergedLines = 0;
- }
- }
- if (!DryRun) {
- for (unsigned i = 0; i < MergedLines; ++i) {
- join(*I[i], *I[i + 1]);
- }
- }
- I += MergedLines;
-
- bool FixIndentation =
- FixBadIndentation && (LevelIndent != FirstTok->OriginalColumn);
- if (TheLine.First->is(tok::eof)) {
- if (PreviousLine && PreviousLine->Affected && !DryRun) {
- // Remove the file's trailing whitespace.
- unsigned Newlines = std::min(FirstTok->NewlinesBefore, 1u);
- Whitespaces->replaceWhitespace(*TheLine.First, Newlines,
- /*IndentLevel=*/0, /*Spaces=*/0,
- /*TargetColumn=*/0);
- }
- } else if (TheLine.Type != LT_Invalid &&
- (TheLine.Affected || FixIndentation)) {
- if (FirstTok->WhitespaceRange.isValid()) {
- if (!DryRun)
- formatFirstToken(*TheLine.First, PreviousLine, TheLine.Level,
- Indent, TheLine.InPPDirective);
- } else {
- Indent = LevelIndent = FirstTok->OriginalColumn;
- }
-
- // If everything fits on a single line, just put it there.
- unsigned ColumnLimit = Style.ColumnLimit;
- if (I + 1 != E) {
- AnnotatedLine *NextLine = I[1];
- if (NextLine->InPPDirective && !NextLine->First->HasUnescapedNewline)
- ColumnLimit = getColumnLimit(TheLine.InPPDirective);
- }
-
- if (TheLine.Last->TotalLength + Indent <= ColumnLimit ||
- TheLine.Type == LT_ImportStatement) {
- LineState State = Indenter->getInitialState(Indent, &TheLine, DryRun);
- while (State.NextToken) {
- formatChildren(State, /*Newline=*/false, /*DryRun=*/false, Penalty);
- Indenter->addTokenToState(State, /*Newline=*/false, DryRun);
- }
- } else if (Style.ColumnLimit == 0) {
- // FIXME: Implement nested blocks for ColumnLimit = 0.
- NoColumnLimitFormatter Formatter(Indenter);
- if (!DryRun)
- Formatter.format(Indent, &TheLine);
- } else {
- Penalty += format(TheLine, Indent, DryRun);
- }
-
- if (!TheLine.InPPDirective)
- IndentForLevel[TheLine.Level] = LevelIndent;
- } else if (TheLine.ChildrenAffected) {
- format(TheLine.Children, DryRun);
- } else {
- // Format the first token if necessary, and notify the WhitespaceManager
- // about the unchanged whitespace.
- for (FormatToken *Tok = TheLine.First; Tok; Tok = Tok->Next) {
- if (Tok == TheLine.First &&
- (Tok->NewlinesBefore > 0 || Tok->IsFirst)) {
- unsigned LevelIndent = Tok->OriginalColumn;
- if (!DryRun) {
- // Remove trailing whitespace of the previous line.
- if ((PreviousLine && PreviousLine->Affected) ||
- TheLine.LeadingEmptyLinesAffected) {
- formatFirstToken(*Tok, PreviousLine, TheLine.Level, LevelIndent,
- TheLine.InPPDirective);
- } else {
- Whitespaces->addUntouchableToken(*Tok, TheLine.InPPDirective);
- }
- }
-
- if (static_cast<int>(LevelIndent) - Offset >= 0)
- LevelIndent -= Offset;
- if (Tok->isNot(tok::comment) && !TheLine.InPPDirective)
- IndentForLevel[TheLine.Level] = LevelIndent;
- } else if (!DryRun) {
- Whitespaces->addUntouchableToken(*Tok, TheLine.InPPDirective);
- }
- }
- }
- if (!DryRun) {
- for (FormatToken *Tok = TheLine.First; Tok; Tok = Tok->Next) {
- Tok->Finalized = true;
- }
- }
- PreviousLine = *I;
- }
- PenaltyCache[CacheKey] = Penalty;
- return Penalty;
- }
-
-private:
- /// \brief Formats an \c AnnotatedLine and returns the penalty.
- ///
- /// If \p DryRun is \c false, directly applies the changes.
- unsigned format(const AnnotatedLine &Line, unsigned FirstIndent,
- bool DryRun) {
- 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);
- }
-
- /// \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 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 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 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)
- return 0;
- if (RootToken.isAccessSpecifier(false) || RootToken.isObjCAccessSpecifier())
- return Style.AccessModifierOffset;
- return 0;
- }
-
- /// \brief Add a new line and the required indent before the first Token
- /// of the \c UnwrappedLine if there was no structural parsing error.
- void formatFirstToken(FormatToken &RootToken,
- const AnnotatedLine *PreviousLine, unsigned IndentLevel,
- unsigned Indent, bool InPPDirective) {
- 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())
- Newlines = std::min(1u, Newlines);
-
- Whitespaces->replaceWhitespace(RootToken, Newlines, IndentLevel, Indent,
- Indent, InPPDirective &&
- !RootToken.HasUnescapedNewline);
- }
-
- /// \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;
- }
-
- 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;
- }
- }
-
- unsigned getColumnLimit(bool InPPDirective) const {
- // In preprocessor directives reserve two chars for trailing " \"
- return Style.ColumnLimit - (InPPDirective ? 2 : 0);
- }
-
- struct CompareLineStatePointers {
- bool operator()(LineState *obj1, LineState *obj2) const {
- return *obj1 < *obj2;
- }
- };
-
- /// \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 = false) {
- 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 > 10000)
- 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;
- }
-
- void reconstructPath(LineState &State, StateNode *Current) {
- std::deque<StateNode *> Path;
- // We do not need a break before the initial token.
- while (Current->Previous) {
- Path.push_front(Current);
- Current = Current->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({
- if ((*I)->NewLine) {
- llvm::dbgs() << "Penalty for placing "
- << (*I)->Previous->State.NextToken->Tok.getName() << ": "
- << Penalty << "\n";
- }
- });
- }
- }
-
- /// \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 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) {
- FormatToken &Previous = *State.NextToken->Previous;
- const FormatToken *LBrace = State.NextToken->getPreviousNonComment();
- 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.FirstIndent - State.Line->Level * Style.IndentWidth;
- if (State.Stack.size() < 2 ||
- !State.Stack[State.Stack.size() - 2].NestedBlockInlined) {
- AdditionalIndent = State.Stack.back().Indent -
- Previous.Children[0]->Level * Style.IndentWidth;
- }
-
- Penalty += 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 += format(*Previous.Children[0], State.Column + 1, DryRun);
-
- State.Column += 1 + Previous.Children[0]->Last->TotalLength;
- return true;
- }
-
- ContinuationIndenter *Indenter;
- WhitespaceManager *Whitespaces;
- FormatStyle Style;
- LineJoiner Joiner;
-
- llvm::SpecificBumpPtrAllocator<StateNode> Allocator;
-
- // Cache to store the penalty of formatting a vector of AnnotatedLines
- // starting from a specific additional offset. Improves performance if there
- // are many nested blocks.
- std::map<std::pair<const SmallVectorImpl<AnnotatedLine *> *, unsigned>,
- unsigned> PenaltyCache;
-};
-
class FormatTokenLexer {
public:
FormatTokenLexer(SourceManager &SourceMgr, FileID ID, FormatStyle &Style,
Added: cfe/trunk/lib/Format/UnwrappedLineFormatter.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Format/UnwrappedLineFormatter.cpp?rev=223936&view=auto
==============================================================================
--- cfe/trunk/lib/Format/UnwrappedLineFormatter.cpp (added)
+++ cfe/trunk/lib/Format/UnwrappedLineFormatter.cpp Wed Dec 10 13:00:42 2014
@@ -0,0 +1,699 @@
+//===--- 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.First->is(tok::kw_extern) && Next && Next->isStringLiteral() &&
+ NextNext && NextNext->is(tok::l_brace);
+}
+
+class LineJoiner {
+public:
+ LineJoiner(const FormatStyle &Style) : Style(Style) {}
+
+ /// \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) {
+ // We can never merge stuff if there are trailing line comments.
+ const AnnotatedLine *TheLine = *I;
+ if (TheLine->Last->is(TT_LineComment))
+ 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;
+
+ if (I + 1 == E || I[1]->Type == LT_Invalid || I[1]->First->MustBreakBefore)
+ return 0;
+
+ // 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.BreakBeforeBraces == FormatStyle::BS_Attach
+ ? tryMergeSimpleBlock(I, E, Limit)
+ : 0;
+ }
+ if (I[1]->First->is(TT_FunctionLBrace) &&
+ Style.BreakBeforeBraces != FormatStyle::BS_Attach) {
+ 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;
+ }
+
+private:
+ unsigned
+ tryMergeSimplePPDirective(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
+ SmallVectorImpl<AnnotatedLine *>::const_iterator E,
+ unsigned Limit) {
+ if (Limit == 0)
+ return 0;
+ if (!I[1]->InPPDirective || I[1]->First->HasUnescapedNewline)
+ 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.BreakBeforeBraces == FormatStyle::BS_Allman ||
+ Style.BreakBeforeBraces == FormatStyle::BS_GNU) &&
+ (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.First->is(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))
+ 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.
+ 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))
+ return 0;
+ if (Line.First->isOneOf(tok::kw_if, tok::kw_while, tok::kw_do, tok::kw_try,
+ tok::kw_catch, tok::kw_for, tok::r_brace)) {
+ if (!Style.AllowShortBlocksOnASingleLine)
+ return 0;
+ if (!Style.AllowShortIfStatementsOnASingleLine &&
+ Line.First->is(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.
+ if (Line.First->isOneOf(tok::kw_try, tok::kw_catch))
+ 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.First->isNot(tok::kw_namespace) &&
+ !startsExternCBlock(Line)) {
+ // We don't merge short records.
+ if (Line.First->isOneOf(tok::kw_class, tok::kw_union, tok::kw_struct))
+ 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;
+
+ 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;
+ }
+
+ const FormatStyle &Style;
+};
+
+class NoColumnLimitFormatter {
+public:
+ NoColumnLimitFormatter(ContinuationIndenter *Indenter) : Indenter(Indenter) {}
+
+ /// \brief Formats the line starting at \p State, simply keeping all of the
+ /// input's line breaking decisions.
+ void format(unsigned FirstIndent, const AnnotatedLine *Line) {
+ LineState State =
+ Indenter->getInitialState(FirstIndent, Line, /*DryRun=*/false);
+ while (State.NextToken) {
+ bool Newline =
+ Indenter->mustBreak(State) ||
+ (Indenter->canBreak(State) && State.NextToken->NewlinesBefore > 0);
+ Indenter->addTokenToState(State, Newline, /*DryRun=*/false);
+ }
+ }
+
+private:
+ ContinuationIndenter *Indenter;
+};
+
+} // namespace
+
+unsigned
+UnwrappedLineFormatter::format(const SmallVectorImpl<AnnotatedLine *> &Lines,
+ bool DryRun, int AdditionalIndent,
+ bool FixBadIndentation) {
+ LineJoiner Joiner(Style);
+
+ // 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;
+ std::vector<int> IndentForLevel;
+ for (unsigned i = 0, e = Lines[0]->Level; i != e; ++i)
+ IndentForLevel.push_back(Style.IndentWidth * i + AdditionalIndent);
+ const AnnotatedLine *PreviousLine = nullptr;
+ for (SmallVectorImpl<AnnotatedLine *>::const_iterator I = Lines.begin(),
+ E = Lines.end();
+ I != E; ++I) {
+ const AnnotatedLine &TheLine = **I;
+ const FormatToken *FirstTok = TheLine.First;
+ int Offset = getIndentOffset(*FirstTok);
+
+ // Determine indent and try to merge multiple unwrapped lines.
+ unsigned Indent;
+ if (TheLine.InPPDirective) {
+ Indent = TheLine.Level * Style.IndentWidth;
+ } else {
+ while (IndentForLevel.size() <= TheLine.Level)
+ IndentForLevel.push_back(-1);
+ IndentForLevel.resize(TheLine.Level + 1);
+ Indent = getIndent(IndentForLevel, TheLine.Level);
+ }
+ unsigned LevelIndent = Indent;
+ if (static_cast<int>(Indent) + Offset >= 0)
+ Indent += Offset;
+
+ // Merge multiple lines if possible.
+ unsigned MergedLines = Joiner.tryFitMultipleLinesInOne(Indent, I, E);
+ 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 (I[i + 1]->First->NewlinesBefore > 0)
+ MergedLines = 0;
+ }
+ }
+ if (!DryRun) {
+ for (unsigned i = 0; i < MergedLines; ++i) {
+ join(*I[i], *I[i + 1]);
+ }
+ }
+ I += MergedLines;
+
+ bool FixIndentation =
+ FixBadIndentation && (LevelIndent != FirstTok->OriginalColumn);
+ if (TheLine.First->is(tok::eof)) {
+ if (PreviousLine && PreviousLine->Affected && !DryRun) {
+ // Remove the file's trailing whitespace.
+ unsigned Newlines = std::min(FirstTok->NewlinesBefore, 1u);
+ Whitespaces->replaceWhitespace(*TheLine.First, Newlines,
+ /*IndentLevel=*/0, /*Spaces=*/0,
+ /*TargetColumn=*/0);
+ }
+ } else if (TheLine.Type != LT_Invalid &&
+ (TheLine.Affected || FixIndentation)) {
+ if (FirstTok->WhitespaceRange.isValid()) {
+ if (!DryRun)
+ formatFirstToken(*TheLine.First, PreviousLine, TheLine.Level, Indent,
+ TheLine.InPPDirective);
+ } else {
+ Indent = LevelIndent = FirstTok->OriginalColumn;
+ }
+
+ // If everything fits on a single line, just put it there.
+ unsigned ColumnLimit = Style.ColumnLimit;
+ if (I + 1 != E) {
+ AnnotatedLine *NextLine = I[1];
+ if (NextLine->InPPDirective && !NextLine->First->HasUnescapedNewline)
+ ColumnLimit = getColumnLimit(TheLine.InPPDirective);
+ }
+
+ if (TheLine.Last->TotalLength + Indent <= ColumnLimit ||
+ TheLine.Type == LT_ImportStatement) {
+ LineState State = Indenter->getInitialState(Indent, &TheLine, DryRun);
+ while (State.NextToken) {
+ formatChildren(State, /*Newline=*/false, /*DryRun=*/false, Penalty);
+ Indenter->addTokenToState(State, /*Newline=*/false, DryRun);
+ }
+ } else if (Style.ColumnLimit == 0) {
+ // FIXME: Implement nested blocks for ColumnLimit = 0.
+ NoColumnLimitFormatter Formatter(Indenter);
+ if (!DryRun)
+ Formatter.format(Indent, &TheLine);
+ } else {
+ Penalty += format(TheLine, Indent, DryRun);
+ }
+
+ if (!TheLine.InPPDirective)
+ IndentForLevel[TheLine.Level] = LevelIndent;
+ } else if (TheLine.ChildrenAffected) {
+ format(TheLine.Children, DryRun);
+ } else {
+ // Format the first token if necessary, and notify the WhitespaceManager
+ // about the unchanged whitespace.
+ for (FormatToken *Tok = TheLine.First; Tok; Tok = Tok->Next) {
+ if (Tok == TheLine.First && (Tok->NewlinesBefore > 0 || Tok->IsFirst)) {
+ unsigned LevelIndent = Tok->OriginalColumn;
+ if (!DryRun) {
+ // Remove trailing whitespace of the previous line.
+ if ((PreviousLine && PreviousLine->Affected) ||
+ TheLine.LeadingEmptyLinesAffected) {
+ formatFirstToken(*Tok, PreviousLine, TheLine.Level, LevelIndent,
+ TheLine.InPPDirective);
+ } else {
+ Whitespaces->addUntouchableToken(*Tok, TheLine.InPPDirective);
+ }
+ }
+
+ if (static_cast<int>(LevelIndent) - Offset >= 0)
+ LevelIndent -= Offset;
+ if (Tok->isNot(tok::comment) && !TheLine.InPPDirective)
+ IndentForLevel[TheLine.Level] = LevelIndent;
+ } else if (!DryRun) {
+ Whitespaces->addUntouchableToken(*Tok, TheLine.InPPDirective);
+ }
+ }
+ }
+ if (!DryRun) {
+ for (FormatToken *Tok = TheLine.First; Tok; Tok = Tok->Next) {
+ Tok->Finalized = true;
+ }
+ }
+ PreviousLine = *I;
+ }
+ PenaltyCache[CacheKey] = Penalty;
+ return Penalty;
+}
+
+unsigned UnwrappedLineFormatter::format(const AnnotatedLine &Line,
+ unsigned FirstIndent, bool DryRun) {
+ 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);
+}
+
+void UnwrappedLineFormatter::formatFirstToken(FormatToken &RootToken,
+ const AnnotatedLine *PreviousLine,
+ unsigned IndentLevel,
+ unsigned Indent,
+ bool InPPDirective) {
+ 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())
+ Newlines = std::min(1u, Newlines);
+
+ Whitespaces->replaceWhitespace(RootToken, Newlines, IndentLevel, Indent,
+ Indent, InPPDirective &&
+ !RootToken.HasUnescapedNewline);
+}
+
+/// \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 UnwrappedLineFormatter::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;
+}
+
+void UnwrappedLineFormatter::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;
+ }
+}
+
+unsigned UnwrappedLineFormatter::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 > 10000)
+ 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;
+}
+
+void UnwrappedLineFormatter::reconstructPath(LineState &State,
+ StateNode *Current) {
+ std::deque<StateNode *> Path;
+ // We do not need a break before the initial token.
+ while (Current->Previous) {
+ Path.push_front(Current);
+ Current = Current->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({
+ if ((*I)->NewLine) {
+ llvm::dbgs() << "Penalty for placing "
+ << (*I)->Previous->State.NextToken->Tok.getName() << ": "
+ << Penalty << "\n";
+ }
+ });
+ }
+}
+
+void UnwrappedLineFormatter::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);
+}
+
+bool UnwrappedLineFormatter::formatChildren(LineState &State, bool NewLine,
+ bool DryRun, unsigned &Penalty) {
+ FormatToken &Previous = *State.NextToken->Previous;
+ const FormatToken *LBrace = State.NextToken->getPreviousNonComment();
+ 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.FirstIndent - State.Line->Level * Style.IndentWidth;
+ if (State.Stack.size() < 2 ||
+ !State.Stack[State.Stack.size() - 2].NestedBlockInlined) {
+ AdditionalIndent = State.Stack.back().Indent -
+ Previous.Children[0]->Level * Style.IndentWidth;
+ }
+
+ Penalty += 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 += format(*Previous.Children[0], State.Column + 1, DryRun);
+
+ State.Column += 1 + Previous.Children[0]->Last->TotalLength;
+ return true;
+}
+
+} // namespace format
+} // namespace clang
Added: cfe/trunk/lib/Format/UnwrappedLineFormatter.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Format/UnwrappedLineFormatter.h?rev=223936&view=auto
==============================================================================
--- cfe/trunk/lib/Format/UnwrappedLineFormatter.h (added)
+++ cfe/trunk/lib/Format/UnwrappedLineFormatter.h Wed Dec 10 13:00:42 2014
@@ -0,0 +1,168 @@
+//===--- UnwrappedLineFormatter.h - Format C++ code -------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// \brief Implements a combinartorial exploration of all the different
+/// linebreaks unwrapped lines can be formatted in.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_LIB_FORMAT_UNWRAPPEDLINEFORMATTER_H
+#define LLVM_CLANG_LIB_FORMAT_UNWRAPPEDLINEFORMATTER_H
+
+#include "ContinuationIndenter.h"
+#include "clang/Format/Format.h"
+#include <map>
+#include <queue>
+#include <string>
+
+namespace clang {
+namespace format {
+
+class ContinuationIndenter;
+class WhitespaceManager;
+
+class UnwrappedLineFormatter {
+public:
+ UnwrappedLineFormatter(ContinuationIndenter *Indenter,
+ WhitespaceManager *Whitespaces,
+ const FormatStyle &Style)
+ : Indenter(Indenter), Whitespaces(Whitespaces), Style(Style) {}
+
+ unsigned format(const SmallVectorImpl<AnnotatedLine *> &Lines, bool DryRun,
+ int AdditionalIndent = 0, bool FixBadIndentation = false);
+
+private:
+ /// \brief Formats an \c AnnotatedLine and returns the penalty.
+ ///
+ /// If \p DryRun is \c false, directly applies the changes.
+ unsigned format(const AnnotatedLine &Line, unsigned FirstIndent,
+ bool DryRun);
+
+ /// \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 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 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 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)
+ return 0;
+ if (RootToken.isAccessSpecifier(false) || RootToken.isObjCAccessSpecifier())
+ return Style.AccessModifierOffset;
+ return 0;
+ }
+
+ /// \brief Add a new line and the required indent before the first Token
+ /// of the \c UnwrappedLine if there was no structural parsing error.
+ void formatFirstToken(FormatToken &RootToken,
+ const AnnotatedLine *PreviousLine, unsigned IndentLevel,
+ unsigned Indent, bool InPPDirective);
+
+ /// \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);
+
+ void join(AnnotatedLine &A, const AnnotatedLine &B);
+
+ unsigned getColumnLimit(bool InPPDirective) const {
+ // In preprocessor directives reserve two chars for trailing " \"
+ return Style.ColumnLimit - (InPPDirective ? 2 : 0);
+ }
+
+ struct CompareLineStatePointers {
+ bool operator()(LineState *obj1, LineState *obj2) const {
+ return *obj1 < *obj2;
+ }
+ };
+
+ /// \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 = false);
+
+ void reconstructPath(LineState &State, StateNode *Current);
+
+ /// \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);
+
+ /// \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);
+
+ ContinuationIndenter *Indenter;
+ WhitespaceManager *Whitespaces;
+ FormatStyle Style;
+
+ llvm::SpecificBumpPtrAllocator<StateNode> Allocator;
+
+ // Cache to store the penalty of formatting a vector of AnnotatedLines
+ // starting from a specific additional offset. Improves performance if there
+ // are many nested blocks.
+ std::map<std::pair<const SmallVectorImpl<AnnotatedLine *> *, unsigned>,
+ unsigned> PenaltyCache;
+};
+} // end namespace format
+} // end namespace clang
+
+#endif // LLVM_CLANG_LIB_FORMAT_UNWRAPPEDLINEFORMATTER_H
More information about the cfe-commits
mailing list