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

705 lines
23 KiB
C++

//===--- Format.cpp - Format C++ code -------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief This file implements functions declared in Format.h. This will be
/// split into separate files as we go.
///
/// This is EXPERIMENTAL code under heavy development. It is not in a state yet,
/// where it can be used to format real code.
///
//===----------------------------------------------------------------------===//
#include "clang/Format/Format.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Lex/Lexer.h"
#include "UnwrappedLineParser.h"
namespace clang {
namespace format {
// FIXME: Move somewhere sane.
struct TokenAnnotation {
enum TokenType { TT_Unknown, TT_TemplateOpener, TT_BinaryOperator,
TT_UnaryOperator, TT_OverloadedOperator, TT_PointerOrReference,
TT_ConditionalExpr, TT_LineComment, TT_BlockComment };
TokenType Type;
/// \brief The current parenthesis level, i.e. the number of opening minus
/// the number of closing parenthesis left of the current position.
unsigned ParenLevel;
bool SpaceRequiredBefore;
bool CanBreakBefore;
bool MustBreakBefore;
};
using llvm::MutableArrayRef;
FormatStyle getLLVMStyle() {
FormatStyle LLVMStyle;
LLVMStyle.ColumnLimit = 80;
LLVMStyle.MaxEmptyLinesToKeep = 1;
LLVMStyle.PointerAndReferenceBindToType = false;
LLVMStyle.AccessModifierOffset = -2;
LLVMStyle.SplitTemplateClosingGreater = true;
return LLVMStyle;
}
FormatStyle getGoogleStyle() {
FormatStyle GoogleStyle;
GoogleStyle.ColumnLimit = 80;
GoogleStyle.MaxEmptyLinesToKeep = 1;
GoogleStyle.PointerAndReferenceBindToType = true;
GoogleStyle.AccessModifierOffset = -1;
GoogleStyle.SplitTemplateClosingGreater = false;
return GoogleStyle;
}
struct OptimizationParameters {
unsigned PenaltyExtraLine;
unsigned PenaltyIndentLevel;
};
class UnwrappedLineFormatter {
public:
UnwrappedLineFormatter(const FormatStyle &Style, SourceManager &SourceMgr,
const UnwrappedLine &Line,
const std::vector<TokenAnnotation> &Annotations,
tooling::Replacements &Replaces)
: Style(Style),
SourceMgr(SourceMgr),
Line(Line),
Annotations(Annotations),
Replaces(Replaces) {
Parameters.PenaltyExtraLine = 100;
Parameters.PenaltyIndentLevel = 5;
}
void format() {
formatFirstToken();
count = 0;
IndentState State;
State.Column = Line.Level * 2 + Line.Tokens[0].Tok.getLength();
State.CtorInitializerOnNewLine = false;
State.InCtorInitializer = false;
State.ConsumedTokens = 1;
//State.UsedIndent.push_back(Line.Level * 2);
State.Indent.push_back(Line.Level * 2 + 4);
State.LastSpace.push_back(Line.Level * 2);
// Start iterating at 1 as we have correctly formatted of Token #0 above.
for (unsigned i = 1, n = Line.Tokens.size(); i != n; ++i) {
unsigned NoBreak = calcPenalty(State, false, UINT_MAX);
unsigned Break = calcPenalty(State, true, NoBreak);
addToken(Break < NoBreak, false, State);
}
}
private:
/// \brief The current state when indenting a unwrapped line.
///
/// As the indenting tries different combinations this is copied by value.
struct IndentState {
/// \brief The number of used columns in the current line.
unsigned Column;
/// \brief The number of tokens already consumed.
unsigned ConsumedTokens;
/// \brief The position to which a specific parenthesis level needs to be
/// indented.
std::vector<unsigned> Indent;
std::vector<unsigned> LastSpace;
bool CtorInitializerOnNewLine;
bool InCtorInitializer;
/// \brief Comparison operator to be able to used \c IndentState in \c map.
bool operator<(const IndentState &Other) const {
if (Other.ConsumedTokens != ConsumedTokens)
return Other.ConsumedTokens > ConsumedTokens;
if (Other.Column != Column)
return Other.Column > Column;
if (Other.Indent.size() != Indent.size())
return Other.Indent.size() > Indent.size();
for (int i = 0, e = Indent.size(); i != e; ++i) {
if (Other.Indent[i] != Indent[i])
return Other.Indent[i] > Indent[i];
}
if (Other.LastSpace.size() != LastSpace.size())
return Other.LastSpace.size() > LastSpace.size();
for (int i = 0, e = LastSpace.size(); i != e; ++i) {
if (Other.LastSpace[i] != LastSpace[i])
return Other.LastSpace[i] > LastSpace[i];
}
return false;
}
};
/// Append the next token to \p State.
void addToken(bool Newline, bool DryRun, IndentState &State) {
unsigned Index = State.ConsumedTokens;
const FormatToken &Current = Line.Tokens[Index];
const FormatToken &Previous = Line.Tokens[Index - 1];
unsigned ParenLevel = Annotations[Index].ParenLevel;
if (Current.Tok.is(tok::l_paren) || Current.Tok.is(tok::l_square) ||
Annotations[Index].Type == TokenAnnotation::TT_TemplateOpener) {
State.Indent.push_back(4 + State.LastSpace.back());
State.LastSpace.push_back(State.LastSpace.back());
}
if (Newline) {
if (Current.Tok.is(tok::string_literal) &&
Previous.Tok.is(tok::string_literal))
State.Column = State.Column - Previous.Tok.getLength();
else if (Previous.Tok.is(tok::equal) && ParenLevel != 0)
State.Column = State.Indent[ParenLevel] + 4;
else
State.Column = State.Indent[ParenLevel];
if (!DryRun)
replaceWhitespace(Current, 1, State.Column);
State.Column += Current.Tok.getLength();
State.LastSpace[ParenLevel] = State.Indent[ParenLevel];
if (Current.Tok.is(tok::colon) &&
Annotations[Index].Type != TokenAnnotation::TT_ConditionalExpr) {
State.Indent[ParenLevel] += 2;
State.CtorInitializerOnNewLine = true;
State.InCtorInitializer = true;
}
} else {
unsigned Spaces = Annotations[Index].SpaceRequiredBefore ? 1 : 0;
if (Annotations[Index].Type == TokenAnnotation::TT_LineComment)
Spaces = 2;
if (!DryRun)
replaceWhitespace(Current, 0, Spaces);
if (Previous.Tok.is(tok::l_paren))
State.Indent[ParenLevel] = State.Column;
if (Previous.Tok.is(tok::less) &&
Annotations[Index - 1].Type == TokenAnnotation::TT_TemplateOpener)
State.Indent[ParenLevel] = State.Column;
if (Current.Tok.is(tok::colon)) {
State.Indent[ParenLevel] = State.Column + 3;
State.InCtorInitializer = true;
}
// Top-level spaces are exempt as that mostly leads to better results.
if (Spaces > 0 && ParenLevel != 0)
State.LastSpace[ParenLevel] = State.Column + Spaces;
State.Column += Current.Tok.getLength() + Spaces;
}
if (Current.Tok.is(tok::r_paren) || Current.Tok.is(tok::r_square) ||
Annotations[Index].Type == TokenAnnotation::TT_TemplateOpener) {
State.Indent.pop_back();
State.LastSpace.pop_back();
}
++State.ConsumedTokens;
}
typedef std::map<IndentState, unsigned> StateMap;
StateMap Memory;
unsigned splitPenalty(const FormatToken &Token) {
if (Token.Tok.is(tok::semi))
return 0;
if (Token.Tok.is(tok::comma))
return 1;
if (Token.Tok.is(tok::equal) || Token.Tok.is(tok::l_paren) ||
Token.Tok.is(tok::pipepipe) || Token.Tok.is(tok::ampamp))
return 2;
return 3;
}
/// \brief Calculate the number of lines needed to format the remaining part
/// of the unwrapped line.
///
/// Assumes the formatting so far has led to
/// the \c IndentState \p State. If \p NewLine is set, a new line will be
/// added after the previous token.
///
/// \param StopAt is used for optimization. If we can determine that we'll
/// definitely need at least \p StopAt additional lines, we already know of a
/// better solution.
unsigned calcPenalty(IndentState State, bool NewLine, unsigned StopAt) {
// We are at the end of the unwrapped line, so we don't need any more lines.
if (State.ConsumedTokens >= Line.Tokens.size())
return 0;
if (!NewLine && Annotations[State.ConsumedTokens].MustBreakBefore)
return UINT_MAX;
if (NewLine && !Annotations[State.ConsumedTokens].CanBreakBefore)
return UINT_MAX;
if (State.ConsumedTokens > 0 && !NewLine &&
State.CtorInitializerOnNewLine &&
Line.Tokens[State.ConsumedTokens - 1].Tok.is(tok::comma))
return UINT_MAX;
if (NewLine && State.InCtorInitializer && !State.CtorInitializerOnNewLine)
return UINT_MAX;
addToken(NewLine, true, State);
// Exceeding column limit is bad.
if (State.Column > Style.ColumnLimit)
return UINT_MAX;
unsigned CurrentPenalty = 0;
if (NewLine) {
CurrentPenalty += Parameters.PenaltyIndentLevel *
Annotations[State.ConsumedTokens - 1].ParenLevel +
Parameters.PenaltyExtraLine +
splitPenalty(Line.Tokens[State.ConsumedTokens - 2]);
}
if (StopAt <= CurrentPenalty)
return UINT_MAX;
StopAt -= CurrentPenalty;
// Has this state already been examined?
StateMap::iterator I = Memory.find(State);
if (I != Memory.end())
return I->second;
++count;
unsigned NoBreak = calcPenalty(State, false, StopAt);
unsigned WithBreak = calcPenalty(State, true, std::min(StopAt, NoBreak));
unsigned Result = std::min(NoBreak, WithBreak);
if (Result != UINT_MAX)
Result += CurrentPenalty;
Memory[State] = Result;
assert(Memory.find(State) != Memory.end());
return Result;
}
/// \brief Replaces the whitespace in front of \p Tok. Only call once for
/// each \c FormatToken.
void replaceWhitespace(const FormatToken &Tok, unsigned NewLines,
unsigned Spaces) {
Replaces.insert(tooling::Replacement(
SourceMgr, Tok.WhiteSpaceStart, Tok.WhiteSpaceLength,
std::string(NewLines, '\n') + std::string(Spaces, ' ')));
}
/// \brief Add a new line and the required indent before the first Token
/// of the \c UnwrappedLine.
void formatFirstToken() {
const FormatToken &Token = Line.Tokens[0];
if (Token.WhiteSpaceStart.isValid()) {
unsigned Newlines =
std::min(Token.NewlinesBefore, Style.MaxEmptyLinesToKeep + 1);
unsigned Offset = SourceMgr.getFileOffset(Token.WhiteSpaceStart);
if (Newlines == 0 && Offset != 0)
Newlines = 1;
unsigned Indent = Line.Level * 2;
if (Token.Tok.is(tok::kw_public) || Token.Tok.is(tok::kw_protected) ||
Token.Tok.is(tok::kw_private))
Indent += Style.AccessModifierOffset;
replaceWhitespace(Token, Newlines, Indent);
}
}
FormatStyle Style;
SourceManager &SourceMgr;
const UnwrappedLine &Line;
const std::vector<TokenAnnotation> &Annotations;
tooling::Replacements &Replaces;
unsigned int count;
OptimizationParameters Parameters;
};
/// \brief Determines extra information about the tokens comprising an
/// \c UnwrappedLine.
class TokenAnnotator {
public:
TokenAnnotator(const UnwrappedLine &Line, const FormatStyle &Style,
SourceManager &SourceMgr)
: Line(Line),
Style(Style),
SourceMgr(SourceMgr) {
}
/// \brief A parser that gathers additional information about tokens.
///
/// The \c TokenAnnotator tries to matches parenthesis and square brakets and
/// store a parenthesis levels. It also tries to resolve matching "<" and ">"
/// into template parameter lists.
class AnnotatingParser {
public:
AnnotatingParser(const SourceManager &SourceMgr,
const SmallVector<FormatToken, 16> &Tokens,
std::vector<TokenAnnotation> &Annotations)
: SourceMgr(SourceMgr),
Tokens(Tokens),
Annotations(Annotations),
Index(0) {
}
bool parseAngle(unsigned Level) {
while (Index < Tokens.size()) {
if (Tokens[Index].Tok.is(tok::greater)) {
Annotations[Index].Type = TokenAnnotation::TT_TemplateOpener;
Annotations[Index].ParenLevel = Level;
next();
return true;
}
if (Tokens[Index].Tok.is(tok::r_paren) ||
Tokens[Index].Tok.is(tok::r_square))
return false;
if (Tokens[Index].Tok.is(tok::pipepipe) ||
Tokens[Index].Tok.is(tok::ampamp) ||
Tokens[Index].Tok.is(tok::question) ||
Tokens[Index].Tok.is(tok::colon))
return false;
consumeToken(Level);
}
return false;
}
bool parseParens(unsigned Level) {
while (Index < Tokens.size()) {
if (Tokens[Index].Tok.is(tok::r_paren)) {
Annotations[Index].ParenLevel = Level;
next();
return true;
}
if (Tokens[Index].Tok.is(tok::r_square))
return false;
consumeToken(Level);
}
return false;
}
bool parseSquare(unsigned Level) {
while (Index < Tokens.size()) {
if (Tokens[Index].Tok.is(tok::r_square)) {
Annotations[Index].ParenLevel = Level;
next();
return true;
}
if (Tokens[Index].Tok.is(tok::r_paren))
return false;
consumeToken(Level);
}
return false;
}
bool parseConditional(unsigned Level) {
while (Index < Tokens.size()) {
if (Tokens[Index].Tok.is(tok::colon)) {
Annotations[Index].Type = TokenAnnotation::TT_ConditionalExpr;
next();
return true;
}
consumeToken(Level);
}
return false;
}
void consumeToken(unsigned Level) {
Annotations[Index].ParenLevel = Level;
unsigned CurrentIndex = Index;
next();
switch (Tokens[CurrentIndex].Tok.getKind()) {
case tok::l_paren:
parseParens(Level + 1);
break;
case tok::l_square:
parseSquare(Level + 1);
break;
case tok::less:
if (parseAngle(Level + 1))
Annotations[CurrentIndex].Type = TokenAnnotation::TT_TemplateOpener;
else {
Annotations[CurrentIndex].Type = TokenAnnotation::TT_BinaryOperator;
Index = CurrentIndex + 1;
}
break;
case tok::greater:
Annotations[CurrentIndex].Type = TokenAnnotation::TT_BinaryOperator;
break;
case tok::kw_operator:
if (!Tokens[Index].Tok.is(tok::l_paren))
Annotations[Index].Type = TokenAnnotation::TT_OverloadedOperator;
next();
break;
case tok::question:
parseConditional(Level);
break;
default:
break;
}
}
void parseLine() {
while (Index < Tokens.size()) {
consumeToken(0);
}
}
void next() {
++Index;
}
private:
const SourceManager &SourceMgr;
const SmallVector<FormatToken, 16> &Tokens;
std::vector<TokenAnnotation> &Annotations;
unsigned Index;
};
void annotate() {
Annotations.clear();
for (int i = 0, e = Line.Tokens.size(); i != e; ++i) {
Annotations.push_back(TokenAnnotation());
}
AnnotatingParser Parser(SourceMgr, Line.Tokens, Annotations);
Parser.parseLine();
determineTokenTypes();
for (int i = 1, e = Line.Tokens.size(); i != e; ++i) {
TokenAnnotation &Annotation = Annotations[i];
Annotation.CanBreakBefore =
canBreakBetween(Line.Tokens[i - 1], Line.Tokens[i]);
if (Line.Tokens[i].Tok.is(tok::colon)) {
if (Line.Tokens[0].Tok.is(tok::kw_case) || i == e - 1) {
Annotation.SpaceRequiredBefore = false;
} else {
Annotation.SpaceRequiredBefore = TokenAnnotation::TT_ConditionalExpr;
}
} else if (Annotations[i - 1].Type == TokenAnnotation::TT_UnaryOperator) {
Annotation.SpaceRequiredBefore = false;
} else if (Annotation.Type == TokenAnnotation::TT_UnaryOperator) {
Annotation.SpaceRequiredBefore =
Line.Tokens[i - 1].Tok.isNot(tok::l_paren);
} else if (Line.Tokens[i - 1].Tok.is(tok::greater) &&
Line.Tokens[i].Tok.is(tok::greater)) {
if (Annotation.Type == TokenAnnotation::TT_TemplateOpener &&
Annotations[i - 1].Type == TokenAnnotation::TT_TemplateOpener)
Annotation.SpaceRequiredBefore = Style.SplitTemplateClosingGreater;
else
Annotation.SpaceRequiredBefore = false;
} else if (
Annotation.Type == TokenAnnotation::TT_BinaryOperator ||
Annotations[i - 1].Type == TokenAnnotation::TT_BinaryOperator) {
Annotation.SpaceRequiredBefore = true;
} else if (
Annotations[i - 1].Type == TokenAnnotation::TT_TemplateOpener &&
Line.Tokens[i].Tok.is(tok::l_paren)) {
Annotation.SpaceRequiredBefore = false;
} else {
Annotation.SpaceRequiredBefore =
spaceRequiredBetween(Line.Tokens[i - 1].Tok, Line.Tokens[i].Tok);
}
if (Annotations[i - 1].Type == TokenAnnotation::TT_LineComment ||
(Line.Tokens[i].Tok.is(tok::string_literal) &&
Line.Tokens[i - 1].Tok.is(tok::string_literal))) {
Annotation.MustBreakBefore = true;
}
if (Annotation.MustBreakBefore)
Annotation.CanBreakBefore = true;
}
}
const std::vector<TokenAnnotation> &getAnnotations() {
return Annotations;
}
private:
void determineTokenTypes() {
for (int i = 0, e = Line.Tokens.size(); i != e; ++i) {
TokenAnnotation &Annotation = Annotations[i];
const FormatToken &Tok = Line.Tokens[i];
if (Tok.Tok.is(tok::star) || Tok.Tok.is(tok::amp))
Annotation.Type = determineStarAmpUsage(i);
else if (Tok.Tok.is(tok::minus) && Line.Tokens[i - 1].Tok.is(tok::equal))
Annotation.Type = TokenAnnotation::TT_UnaryOperator;
else if (isBinaryOperator(Line.Tokens[i]))
Annotation.Type = TokenAnnotation::TT_BinaryOperator;
else if (Tok.Tok.is(tok::comment)) {
StringRef Data(SourceMgr.getCharacterData(Tok.Tok.getLocation()),
Tok.Tok.getLength());
if (Data.startswith("//"))
Annotation.Type = TokenAnnotation::TT_LineComment;
else
Annotation.Type = TokenAnnotation::TT_BlockComment;
}
}
}
bool isBinaryOperator(const FormatToken &Tok) {
switch (Tok.Tok.getKind()) {
case tok::equal:
case tok::equalequal:
case tok::star:
//case tok::amp:
case tok::plus:
case tok::slash:
case tok::minus:
case tok::ampamp:
case tok::pipe:
case tok::pipepipe:
case tok::percent:
return true;
default:
return false;
}
}
TokenAnnotation::TokenType determineStarAmpUsage(unsigned Index) {
if (Index == Annotations.size())
return TokenAnnotation::TT_Unknown;
if (Index == 0 || Line.Tokens[Index - 1].Tok.is(tok::l_paren) ||
Line.Tokens[Index - 1].Tok.is(tok::comma) ||
Annotations[Index - 1].Type == TokenAnnotation::TT_BinaryOperator)
return TokenAnnotation::TT_UnaryOperator;
if (Line.Tokens[Index - 1].Tok.isLiteral() ||
Line.Tokens[Index + 1].Tok.isLiteral())
return TokenAnnotation::TT_BinaryOperator;
return TokenAnnotation::TT_PointerOrReference;
}
bool isIfForOrWhile(Token Tok) {
return Tok.is(tok::kw_if) || Tok.is(tok::kw_for) || Tok.is(tok::kw_while);
}
bool spaceRequiredBetween(Token Left, Token Right) {
if (Left.is(tok::kw_template) && Right.is(tok::less))
return true;
if (Left.is(tok::arrow) || Right.is(tok::arrow))
return false;
if (Left.is(tok::exclaim) || Left.is(tok::tilde))
return false;
if (Left.is(tok::less) || Right.is(tok::greater) || Right.is(tok::less))
return false;
if (Left.is(tok::amp) || Left.is(tok::star))
return Right.isLiteral() || Style.PointerAndReferenceBindToType;
if (Right.is(tok::star) && Left.is(tok::l_paren))
return false;
if (Right.is(tok::amp) || Right.is(tok::star))
return Left.isLiteral() || !Style.PointerAndReferenceBindToType;
if (Left.is(tok::l_square) || Right.is(tok::l_square) ||
Right.is(tok::r_square))
return false;
if (Left.is(tok::coloncolon) || Right.is(tok::coloncolon))
return false;
if (Left.is(tok::period) || Right.is(tok::period))
return false;
if (Left.is(tok::colon) || Right.is(tok::colon))
return true;
if ((Left.is(tok::plusplus) && Right.isAnyIdentifier()) ||
(Left.isAnyIdentifier() && Right.is(tok::plusplus)) ||
(Left.is(tok::minusminus) && Right.isAnyIdentifier()) ||
(Left.isAnyIdentifier() && Right.is(tok::minusminus)))
return false;
if (Left.is(tok::l_paren))
return false;
if (Left.is(tok::hash))
return false;
if (Right.is(tok::r_paren) || Right.is(tok::semi) || Right.is(tok::comma))
return false;
if (Right.is(tok::l_paren)) {
return !Left.isAnyIdentifier() || isIfForOrWhile(Left);
}
return true;
}
bool canBreakBetween(const FormatToken &Left, const FormatToken &Right) {
if (Right.Tok.is(tok::r_paren))
return false;
if (isBinaryOperator(Left))
return true;
return Right.Tok.is(tok::colon) || Left.Tok.is(tok::comma) || Left.Tok.is(
tok::semi) || Left.Tok.is(tok::equal) || Left.Tok.is(tok::ampamp) ||
(Left.Tok.is(tok::l_paren) && !Right.Tok.is(tok::r_paren));
}
const UnwrappedLine &Line;
FormatStyle Style;
SourceManager &SourceMgr;
std::vector<TokenAnnotation> Annotations;
};
class Formatter : public UnwrappedLineConsumer {
public:
Formatter(const FormatStyle &Style, Lexer &Lex, SourceManager &SourceMgr,
const std::vector<CharSourceRange> &Ranges)
: Style(Style),
Lex(Lex),
SourceMgr(SourceMgr),
Ranges(Ranges) {
}
tooling::Replacements format() {
UnwrappedLineParser Parser(Lex, SourceMgr, *this);
Parser.parse();
return Replaces;
}
private:
virtual void formatUnwrappedLine(const UnwrappedLine &TheLine) {
if (TheLine.Tokens.size() == 0)
return;
CharSourceRange LineRange =
CharSourceRange::getTokenRange(TheLine.Tokens.front().Tok.getLocation(),
TheLine.Tokens.back().Tok.getLocation());
for (unsigned i = 0, e = Ranges.size(); i != e; ++i) {
if (SourceMgr.isBeforeInTranslationUnit(LineRange.getEnd(),
Ranges[i].getBegin()) ||
SourceMgr.isBeforeInTranslationUnit(Ranges[i].getEnd(),
LineRange.getBegin()))
continue;
TokenAnnotator Annotator(TheLine, Style, SourceMgr);
Annotator.annotate();
UnwrappedLineFormatter Formatter(Style, SourceMgr, TheLine,
Annotator.getAnnotations(), Replaces);
Formatter.format();
return;
}
}
FormatStyle Style;
Lexer &Lex;
SourceManager &SourceMgr;
tooling::Replacements Replaces;
std::vector<CharSourceRange> Ranges;
};
tooling::Replacements reformat(const FormatStyle &Style, Lexer &Lex,
SourceManager &SourceMgr,
std::vector<CharSourceRange> Ranges) {
Formatter formatter(Style, Lex, SourceMgr, Ranges);
return formatter.format();
}
} // namespace format
} // namespace clang