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Refactor the formatter of clang-format. 

Pull various parts of the UnwrappedLineFormatter into their own
abstractions. NFC.

There are two things left for subsequent changes (to keep this
reasonably small)
- the UnwrappedLineFormatter now has a bad name
- the UnwrappedLineFormatter::format function is still too large

llvm-svn: 236974
This commit is contained in:
Manuel Klimek 2015-05-11 08:21:35 +00:00
parent f0d68d788b
commit d3585dbd1a
3 changed files with 356 additions and 315 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
clang/lib/Format/Format.cpp
View File

@ -1269,9 +1269,9 @@ public:
ContinuationIndenter Indenter(Style, Tokens.getKeywords(), SourceMgr,
Whitespaces, Encoding,
BinPackInconclusiveFunctions);
UnwrappedLineFormatter Formatter(&Indenter, &Whitespaces, Style,
Tokens.getKeywords(), IncompleteFormat);
Formatter.format(AnnotatedLines, /*DryRun=*/false);
UnwrappedLineFormatter(&Indenter, &Whitespaces, Style, Tokens.getKeywords(),
IncompleteFormat)
.format(AnnotatedLines);
return Whitespaces.generateReplacements();
}

568
clang/lib/Format/UnwrappedLineFormatter.cpp
View File

@ -151,8 +151,8 @@ private:
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))
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) &&
@ -161,9 +161,10 @@ private:
return 1;
}
unsigned tryMergeShortCaseLabels(
SmallVectorImpl<AnnotatedLine *>::const_iterator I,
SmallVectorImpl<AnnotatedLine *>::const_iterator E, unsigned Limit) {
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;
@ -307,33 +308,6 @@ private:
const AdditionalKeywords &Keywords;
};
class NoColumnLimitFormatter {
public:
NoColumnLimitFormatter(ContinuationIndenter *Indenter,
UnwrappedLineFormatter *Formatter)
: Indenter(Indenter), Formatter(Formatter) {}
/// \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);
unsigned Penalty = 0;
Formatter->formatChildren(State, Newline, /*DryRun=*/false, Penalty);
Indenter->addTokenToState(State, Newline, /*DryRun=*/false);
}
}
private:
ContinuationIndenter *Indenter;
UnwrappedLineFormatter *Formatter;
};
static void markFinalized(FormatToken *Tok) {
for (; Tok; Tok = Tok->Next) {
Tok->Finalized = true;
@ -342,6 +316,339 @@ static void markFinalized(FormatToken *Tok) {
}
}
#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) {
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) {
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 > 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;
}
/// \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;
};
} // namespace
unsigned
@ -431,17 +738,14 @@ UnwrappedLineFormatter::format(const SmallVectorImpl<AnnotatedLine *> &Lines,
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, Penalty);
Indenter->addTokenToState(State, /*Newline=*/false, DryRun);
}
Penalty += NoLineBreakFormatter(Indenter, Whitespaces, Style, this)
.formatLine(TheLine, Indent, DryRun);
} else if (Style.ColumnLimit == 0) {
NoColumnLimitFormatter Formatter(Indenter, this);
if (!DryRun)
Formatter.format(Indent, &TheLine);
NoColumnLimitLineFormatter(Indenter, Whitespaces, Style, this)
.formatLine(TheLine, Indent, DryRun);
} else {
Penalty += format(TheLine, Indent, DryRun);
Penalty += OptimizingLineFormatter(Indenter, Whitespaces, Style, this)
.formatLine(TheLine, Indent, DryRun);
}
if (!TheLine.InPPDirective)
@ -486,19 +790,6 @@ UnwrappedLineFormatter::format(const SmallVectorImpl<AnnotatedLine *> &Lines,
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,
@ -567,174 +858,5 @@ void UnwrappedLineFormatter::join(AnnotatedLine &A, const AnnotatedLine &B) {
}
}
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;
}
#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
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({
printLineState((*I)->Previous->State);
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) {
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 += 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

97
clang/lib/Format/UnwrappedLineFormatter.h
View File

@ -38,65 +38,12 @@ public:
: Indenter(Indenter), Whitespaces(Whitespaces), Style(Style),
Keywords(Keywords), IncompleteFormat(IncompleteFormat) {}
unsigned format(const SmallVectorImpl<AnnotatedLine *> &Lines, bool DryRun,
int AdditionalIndent = 0, bool FixBadIndentation = false);
/// \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);
/// \brief Format the current block and return the penalty.
unsigned format(const SmallVectorImpl<AnnotatedLine *> &Lines,
bool DryRun = false, 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
@ -133,44 +80,16 @@ private:
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);
ContinuationIndenter *Indenter;
WhitespaceManager *Whitespaces;
FormatStyle Style;
const AdditionalKeywords &Keywords;
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;
ContinuationIndenter *Indenter;
WhitespaceManager *Whitespaces;
const FormatStyle &Style;
const AdditionalKeywords &Keywords;
bool *IncompleteFormat;
};
} // end namespace format