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

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//===--- 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.
///
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "format-formatter"
#include "BreakableToken.h"
#include "TokenAnnotator.h"
#include "UnwrappedLineParser.h"
#include "WhitespaceManager.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/OperatorPrecedence.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Format/Format.h"
#include "clang/Lex/Lexer.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/YAMLTraits.h"
#include <queue>
#include <string>
namespace llvm {
namespace yaml {
template <>
struct ScalarEnumerationTraits<clang::format::FormatStyle::LanguageStandard> {
static void enumeration(IO &IO,
clang::format::FormatStyle::LanguageStandard &Value) {
IO.enumCase(Value, "C++03", clang::format::FormatStyle::LS_Cpp03);
IO.enumCase(Value, "C++11", clang::format::FormatStyle::LS_Cpp11);
IO.enumCase(Value, "Auto", clang::format::FormatStyle::LS_Auto);
}
};
template <>
struct ScalarEnumerationTraits<clang::format::FormatStyle::BraceBreakingStyle> {
static void
enumeration(IO &IO, clang::format::FormatStyle::BraceBreakingStyle &Value) {
IO.enumCase(Value, "Attach", clang::format::FormatStyle::BS_Attach);
IO.enumCase(Value, "Linux", clang::format::FormatStyle::BS_Linux);
IO.enumCase(Value, "Stroustrup", clang::format::FormatStyle::BS_Stroustrup);
}
};
template <> struct MappingTraits<clang::format::FormatStyle> {
static void mapping(llvm::yaml::IO &IO, clang::format::FormatStyle &Style) {
if (IO.outputting()) {
StringRef StylesArray[] = { "LLVM", "Google", "Chromium", "Mozilla" };
ArrayRef<StringRef> Styles(StylesArray);
for (size_t i = 0, e = Styles.size(); i < e; ++i) {
StringRef StyleName(Styles[i]);
clang::format::FormatStyle PredefinedStyle;
if (clang::format::getPredefinedStyle(StyleName, &PredefinedStyle) &&
Style == PredefinedStyle) {
IO.mapOptional("# BasedOnStyle", StyleName);
break;
}
}
} else {
StringRef BasedOnStyle;
IO.mapOptional("BasedOnStyle", BasedOnStyle);
if (!BasedOnStyle.empty())
if (!clang::format::getPredefinedStyle(BasedOnStyle, &Style)) {
IO.setError(Twine("Unknown value for BasedOnStyle: ", BasedOnStyle));
return;
}
}
IO.mapOptional("AccessModifierOffset", Style.AccessModifierOffset);
IO.mapOptional("AlignEscapedNewlinesLeft", Style.AlignEscapedNewlinesLeft);
IO.mapOptional("AllowAllParametersOfDeclarationOnNextLine",
Style.AllowAllParametersOfDeclarationOnNextLine);
IO.mapOptional("AllowShortIfStatementsOnASingleLine",
Style.AllowShortIfStatementsOnASingleLine);
IO.mapOptional("AllowShortLoopsOnASingleLine",
Style.AllowShortLoopsOnASingleLine);
IO.mapOptional("AlwaysBreakTemplateDeclarations",
Style.AlwaysBreakTemplateDeclarations);
IO.mapOptional("BinPackParameters", Style.BinPackParameters);
IO.mapOptional("ColumnLimit", Style.ColumnLimit);
IO.mapOptional("ConstructorInitializerAllOnOneLineOrOnePerLine",
Style.ConstructorInitializerAllOnOneLineOrOnePerLine);
IO.mapOptional("DerivePointerBinding", Style.DerivePointerBinding);
IO.mapOptional("IndentCaseLabels", Style.IndentCaseLabels);
IO.mapOptional("MaxEmptyLinesToKeep", Style.MaxEmptyLinesToKeep);
IO.mapOptional("ObjCSpaceBeforeProtocolList",
Style.ObjCSpaceBeforeProtocolList);
IO.mapOptional("PenaltyBreakComment", Style.PenaltyBreakComment);
IO.mapOptional("PenaltyBreakString", Style.PenaltyBreakString);
IO.mapOptional("PenaltyExcessCharacter", Style.PenaltyExcessCharacter);
IO.mapOptional("PenaltyReturnTypeOnItsOwnLine",
Style.PenaltyReturnTypeOnItsOwnLine);
IO.mapOptional("PointerBindsToType", Style.PointerBindsToType);
IO.mapOptional("SpacesBeforeTrailingComments",
Style.SpacesBeforeTrailingComments);
IO.mapOptional("SpacesInBracedLists", Style.SpacesInBracedLists);
IO.mapOptional("Standard", Style.Standard);
IO.mapOptional("IndentWidth", Style.IndentWidth);
IO.mapOptional("UseTab", Style.UseTab);
IO.mapOptional("BreakBeforeBraces", Style.BreakBeforeBraces);
IO.mapOptional("IndentFunctionDeclarationAfterType",
Style.IndentFunctionDeclarationAfterType);
}
};
}
}
namespace clang {
namespace format {
FormatStyle getLLVMStyle() {
FormatStyle LLVMStyle;
LLVMStyle.AccessModifierOffset = -2;
LLVMStyle.AlignEscapedNewlinesLeft = false;
LLVMStyle.AllowAllParametersOfDeclarationOnNextLine = true;
LLVMStyle.AllowShortIfStatementsOnASingleLine = false;
LLVMStyle.AllowShortLoopsOnASingleLine = false;
LLVMStyle.AlwaysBreakTemplateDeclarations = false;
LLVMStyle.BinPackParameters = true;
LLVMStyle.ColumnLimit = 80;
LLVMStyle.ConstructorInitializerAllOnOneLineOrOnePerLine = false;
LLVMStyle.DerivePointerBinding = false;
LLVMStyle.IndentCaseLabels = false;
LLVMStyle.MaxEmptyLinesToKeep = 1;
LLVMStyle.ObjCSpaceBeforeProtocolList = true;
LLVMStyle.PenaltyBreakComment = 45;
LLVMStyle.PenaltyBreakString = 1000;
LLVMStyle.PenaltyExcessCharacter = 1000000;
LLVMStyle.PenaltyReturnTypeOnItsOwnLine = 75;
LLVMStyle.PointerBindsToType = false;
LLVMStyle.SpacesBeforeTrailingComments = 1;
LLVMStyle.SpacesInBracedLists = true;
LLVMStyle.Standard = FormatStyle::LS_Cpp03;
LLVMStyle.IndentWidth = 2;
LLVMStyle.UseTab = false;
LLVMStyle.BreakBeforeBraces = FormatStyle::BS_Attach;
LLVMStyle.IndentFunctionDeclarationAfterType = false;
return LLVMStyle;
}
FormatStyle getGoogleStyle() {
FormatStyle GoogleStyle;
GoogleStyle.AccessModifierOffset = -1;
GoogleStyle.AlignEscapedNewlinesLeft = true;
GoogleStyle.AllowAllParametersOfDeclarationOnNextLine = true;
GoogleStyle.AllowShortIfStatementsOnASingleLine = true;
GoogleStyle.AllowShortLoopsOnASingleLine = true;
GoogleStyle.AlwaysBreakTemplateDeclarations = true;
GoogleStyle.BinPackParameters = true;
GoogleStyle.ColumnLimit = 80;
GoogleStyle.ConstructorInitializerAllOnOneLineOrOnePerLine = true;
GoogleStyle.DerivePointerBinding = true;
GoogleStyle.IndentCaseLabels = true;
GoogleStyle.MaxEmptyLinesToKeep = 1;
GoogleStyle.ObjCSpaceBeforeProtocolList = false;
GoogleStyle.PenaltyBreakComment = 45;
GoogleStyle.PenaltyBreakString = 1000;
GoogleStyle.PenaltyExcessCharacter = 1000000;
GoogleStyle.PenaltyReturnTypeOnItsOwnLine = 200;
GoogleStyle.PointerBindsToType = true;
GoogleStyle.SpacesBeforeTrailingComments = 2;
GoogleStyle.SpacesInBracedLists = false;
GoogleStyle.Standard = FormatStyle::LS_Auto;
GoogleStyle.IndentWidth = 2;
GoogleStyle.UseTab = false;
GoogleStyle.BreakBeforeBraces = FormatStyle::BS_Attach;
GoogleStyle.IndentFunctionDeclarationAfterType = true;
return GoogleStyle;
}
FormatStyle getChromiumStyle() {
FormatStyle ChromiumStyle = getGoogleStyle();
ChromiumStyle.AllowAllParametersOfDeclarationOnNextLine = false;
ChromiumStyle.AllowShortIfStatementsOnASingleLine = false;
ChromiumStyle.AllowShortLoopsOnASingleLine = false;
ChromiumStyle.BinPackParameters = false;
ChromiumStyle.Standard = FormatStyle::LS_Cpp03;
ChromiumStyle.DerivePointerBinding = false;
return ChromiumStyle;
}
FormatStyle getMozillaStyle() {
FormatStyle MozillaStyle = getLLVMStyle();
MozillaStyle.AllowAllParametersOfDeclarationOnNextLine = false;
MozillaStyle.ConstructorInitializerAllOnOneLineOrOnePerLine = true;
MozillaStyle.DerivePointerBinding = true;
MozillaStyle.IndentCaseLabels = true;
MozillaStyle.ObjCSpaceBeforeProtocolList = false;
MozillaStyle.PenaltyReturnTypeOnItsOwnLine = 200;
MozillaStyle.PointerBindsToType = true;
return MozillaStyle;
}
bool getPredefinedStyle(StringRef Name, FormatStyle *Style) {
if (Name.equals_lower("llvm"))
*Style = getLLVMStyle();
else if (Name.equals_lower("chromium"))
*Style = getChromiumStyle();
else if (Name.equals_lower("mozilla"))
*Style = getMozillaStyle();
else if (Name.equals_lower("google"))
*Style = getGoogleStyle();
else
return false;
return true;
}
llvm::error_code parseConfiguration(StringRef Text, FormatStyle *Style) {
if (Text.trim().empty())
return llvm::make_error_code(llvm::errc::invalid_argument);
llvm::yaml::Input Input(Text);
Input >> *Style;
return Input.error();
}
std::string configurationAsText(const FormatStyle &Style) {
std::string Text;
llvm::raw_string_ostream Stream(Text);
llvm::yaml::Output Output(Stream);
// We use the same mapping method for input and output, so we need a non-const
// reference here.
FormatStyle NonConstStyle = Style;
Output << NonConstStyle;
return Stream.str();
}
// Returns the length of everything up to the first possible line break after
// the ), ], } or > matching \c Tok.
static unsigned getLengthToMatchingParen(const FormatToken &Tok) {
if (Tok.MatchingParen == NULL)
return 0;
FormatToken *End = Tok.MatchingParen;
while (End->Next && !End->Next->CanBreakBefore) {
End = End->Next;
}
return End->TotalLength - Tok.TotalLength + 1;
}
namespace {
class UnwrappedLineFormatter {
public:
UnwrappedLineFormatter(const FormatStyle &Style, SourceManager &SourceMgr,
const AnnotatedLine &Line, unsigned FirstIndent,
const FormatToken *RootToken,
WhitespaceManager &Whitespaces,
encoding::Encoding Encoding)
: Style(Style), SourceMgr(SourceMgr), Line(Line),
FirstIndent(FirstIndent), RootToken(RootToken),
Whitespaces(Whitespaces), Count(0), Encoding(Encoding) {}
/// \brief Formats an \c UnwrappedLine.
void format(const AnnotatedLine *NextLine) {
// Initialize state dependent on indent.
LineState State;
State.Column = FirstIndent;
State.NextToken = RootToken;
State.Stack.push_back(
ParenState(FirstIndent, FirstIndent, /*AvoidBinPacking=*/false,
/*NoLineBreak=*/false));
State.LineContainsContinuedForLoopSection = false;
State.ParenLevel = 0;
State.StartOfStringLiteral = 0;
State.StartOfLineLevel = State.ParenLevel;
State.LowestCallLevel = State.ParenLevel;
State.IgnoreStackForComparison = false;
// The first token has already been indented and thus consumed.
moveStateToNextToken(State, /*DryRun=*/false);
// If everything fits on a single line, just put it there.
unsigned ColumnLimit = Style.ColumnLimit;
if (NextLine && NextLine->InPPDirective &&
!NextLine->First->HasUnescapedNewline)
ColumnLimit = getColumnLimit();
if (Line.Last->TotalLength <= ColumnLimit - FirstIndent) {
while (State.NextToken != NULL) {
addTokenToState(false, false, State);
}
}
// If the ObjC method declaration does not fit on a line, we should format
// it with one arg per line.
if (Line.Type == LT_ObjCMethodDecl)
State.Stack.back().BreakBeforeParameter = true;
// Find best solution in solution space.
analyzeSolutionSpace(State);
}
private:
void DebugTokenState(const FormatToken &FormatTok) {
const Token &Tok = FormatTok.Tok;
llvm::dbgs() << StringRef(SourceMgr.getCharacterData(Tok.getLocation()),
Tok.getLength());
llvm::dbgs();
}
struct ParenState {
ParenState(unsigned Indent, unsigned LastSpace, bool AvoidBinPacking,
bool NoLineBreak)
: Indent(Indent), LastSpace(LastSpace), FirstLessLess(0),
BreakBeforeClosingBrace(false), QuestionColumn(0),
AvoidBinPacking(AvoidBinPacking), BreakBeforeParameter(false),
NoLineBreak(NoLineBreak), ColonPos(0), StartOfFunctionCall(0),
NestedNameSpecifierContinuation(0), CallContinuation(0),
VariablePos(0), ForFakeParenthesis(false) {}
/// \brief The position to which a specific parenthesis level needs to be
/// indented.
unsigned Indent;
/// \brief The position of the last space on each level.
///
/// Used e.g. to break like:
/// functionCall(Parameter, otherCall(
/// OtherParameter));
unsigned LastSpace;
/// \brief The position the first "<<" operator encountered on each level.
///
/// Used to align "<<" operators. 0 if no such operator has been encountered
/// on a level.
unsigned FirstLessLess;
/// \brief Whether a newline needs to be inserted before the block's closing
/// brace.
///
/// We only want to insert a newline before the closing brace if there also
/// was a newline after the beginning left brace.
bool BreakBeforeClosingBrace;
/// \brief The column of a \c ? in a conditional expression;
unsigned QuestionColumn;
/// \brief Avoid bin packing, i.e. multiple parameters/elements on multiple
/// lines, in this context.
bool AvoidBinPacking;
/// \brief Break after the next comma (or all the commas in this context if
/// \c AvoidBinPacking is \c true).
bool BreakBeforeParameter;
/// \brief Line breaking in this context would break a formatting rule.
bool NoLineBreak;
/// \brief The position of the colon in an ObjC method declaration/call.
unsigned ColonPos;
/// \brief The start of the most recent function in a builder-type call.
unsigned StartOfFunctionCall;
/// \brief If a nested name specifier was broken over multiple lines, this
/// contains the start column of the second line. Otherwise 0.
unsigned NestedNameSpecifierContinuation;
/// \brief If a call expression was broken over multiple lines, this
/// contains the start column of the second line. Otherwise 0.
unsigned CallContinuation;
/// \brief The column of the first variable name in a variable declaration.
///
/// Used to align further variables if necessary.
unsigned VariablePos;
/// \brief \c true if this \c ParenState was created for a fake parenthesis.
///
/// Does not need to be considered for memoization / the comparison function
/// as otherwise identical states will have the same fake/non-fake
/// \c ParenStates.
bool ForFakeParenthesis;
bool operator<(const ParenState &Other) const {
if (Indent != Other.Indent)
return Indent < Other.Indent;
if (LastSpace != Other.LastSpace)
return LastSpace < Other.LastSpace;
if (FirstLessLess != Other.FirstLessLess)
return FirstLessLess < Other.FirstLessLess;
if (BreakBeforeClosingBrace != Other.BreakBeforeClosingBrace)
return BreakBeforeClosingBrace;
if (QuestionColumn != Other.QuestionColumn)
return QuestionColumn < Other.QuestionColumn;
if (AvoidBinPacking != Other.AvoidBinPacking)
return AvoidBinPacking;
if (BreakBeforeParameter != Other.BreakBeforeParameter)
return BreakBeforeParameter;
if (NoLineBreak != Other.NoLineBreak)
return NoLineBreak;
if (ColonPos != Other.ColonPos)
return ColonPos < Other.ColonPos;
if (StartOfFunctionCall != Other.StartOfFunctionCall)
return StartOfFunctionCall < Other.StartOfFunctionCall;
if (CallContinuation != Other.CallContinuation)
return CallContinuation < Other.CallContinuation;
if (VariablePos != Other.VariablePos)
return VariablePos < Other.VariablePos;
return false;
}
};
/// \brief The current state when indenting a unwrapped line.
///
/// As the indenting tries different combinations this is copied by value.
struct LineState {
/// \brief The number of used columns in the current line.
unsigned Column;
/// \brief The token that needs to be next formatted.
const FormatToken *NextToken;
/// \brief \c true if this line contains a continued for-loop section.
bool LineContainsContinuedForLoopSection;
/// \brief The level of nesting inside (), [], <> and {}.
unsigned ParenLevel;
/// \brief The \c ParenLevel at the start of this line.
unsigned StartOfLineLevel;
/// \brief The lowest \c ParenLevel of "." or "->" on the current line.
unsigned LowestCallLevel;
/// \brief The start column of the string literal, if we're in a string
/// literal sequence, 0 otherwise.
unsigned StartOfStringLiteral;
/// \brief A stack keeping track of properties applying to parenthesis
/// levels.
std::vector<ParenState> Stack;
/// \brief Ignore the stack of \c ParenStates for state comparison.
///
/// In long and deeply nested unwrapped lines, the current algorithm can
/// be insufficient for finding the best formatting with a reasonable amount
/// of time and memory. Setting this flag will effectively lead to the
/// algorithm not analyzing some combinations. However, these combinations
/// rarely contain the optimal solution: In short, accepting a higher
/// penalty early would need to lead to different values in the \c
/// ParenState stack (in an otherwise identical state) and these different
/// values would need to lead to a significant amount of avoided penalty
/// later.
///
/// FIXME: Come up with a better algorithm instead.
bool IgnoreStackForComparison;
/// \brief Comparison operator to be able to used \c LineState in \c map.
bool operator<(const LineState &Other) const {
if (NextToken != Other.NextToken)
return NextToken < Other.NextToken;
if (Column != Other.Column)
return Column < Other.Column;
if (LineContainsContinuedForLoopSection !=
Other.LineContainsContinuedForLoopSection)
return LineContainsContinuedForLoopSection;
if (ParenLevel != Other.ParenLevel)
return ParenLevel < Other.ParenLevel;
if (StartOfLineLevel != Other.StartOfLineLevel)
return StartOfLineLevel < Other.StartOfLineLevel;
if (LowestCallLevel != Other.LowestCallLevel)
return LowestCallLevel < Other.LowestCallLevel;
if (StartOfStringLiteral != Other.StartOfStringLiteral)
return StartOfStringLiteral < Other.StartOfStringLiteral;
if (IgnoreStackForComparison || Other.IgnoreStackForComparison)
return false;
return Stack < Other.Stack;
}
};
/// \brief Appends the next token to \p State and updates information
/// necessary for indentation.
///
/// Puts the token on the current line if \p Newline is \c false and adds a
/// line break and necessary indentation otherwise.
///
/// If \p DryRun is \c false, also creates and stores the required
/// \c Replacement.
unsigned addTokenToState(bool Newline, bool DryRun, LineState &State) {
const FormatToken &Current = *State.NextToken;
const FormatToken &Previous = *State.NextToken->Previous;
if (State.Stack.size() == 0 || Current.Type == TT_ImplicitStringLiteral) {
// FIXME: Is this correct?
int WhitespaceLength = SourceMgr.getSpellingColumnNumber(
State.NextToken->WhitespaceRange.getEnd()) -
SourceMgr.getSpellingColumnNumber(
State.NextToken->WhitespaceRange.getBegin());
State.Column += WhitespaceLength + State.NextToken->CodePointCount;
State.NextToken = State.NextToken->Next;
return 0;
}
// If we are continuing an expression, we want to indent an extra 4 spaces.
unsigned ContinuationIndent =
std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) + 4;
if (Newline) {
if (Current.is(tok::r_brace)) {
State.Column = Line.Level * Style.IndentWidth;
} else if (Current.is(tok::string_literal) &&
State.StartOfStringLiteral != 0) {
State.Column = State.StartOfStringLiteral;
State.Stack.back().BreakBeforeParameter = true;
} else if (Current.is(tok::lessless) &&
State.Stack.back().FirstLessLess != 0) {
State.Column = State.Stack.back().FirstLessLess;
} else if (Current.isOneOf(tok::period, tok::arrow) &&
Current.Type != TT_DesignatedInitializerPeriod) {
if (State.Stack.back().CallContinuation == 0) {
State.Column = ContinuationIndent;
State.Stack.back().CallContinuation = State.Column;
} else {
State.Column = State.Stack.back().CallContinuation;
}
} else if (Current.Type == TT_ConditionalExpr) {
State.Column = State.Stack.back().QuestionColumn;
} else if (Previous.is(tok::comma) &&
State.Stack.back().VariablePos != 0) {
State.Column = State.Stack.back().VariablePos;
} else if (Previous.ClosesTemplateDeclaration ||
(Current.Type == TT_StartOfName && State.ParenLevel == 0 &&
(!Style.IndentFunctionDeclarationAfterType ||
Line.StartsDefinition))) {
State.Column = State.Stack.back().Indent;
} else if (Current.Type == TT_ObjCSelectorName) {
if (State.Stack.back().ColonPos > Current.CodePointCount) {
State.Column = State.Stack.back().ColonPos - Current.CodePointCount;
} else {
State.Column = State.Stack.back().Indent;
State.Stack.back().ColonPos = State.Column + Current.CodePointCount;
}
} else if (Current.Type == TT_StartOfName ||
Previous.isOneOf(tok::coloncolon, tok::equal) ||
Previous.Type == TT_ObjCMethodExpr) {
State.Column = ContinuationIndent;
} else {
State.Column = State.Stack.back().Indent;
// Ensure that we fall back to indenting 4 spaces instead of just
// flushing continuations left.
if (State.Column == FirstIndent)
State.Column += 4;
}
if (Current.is(tok::question))
State.Stack.back().BreakBeforeParameter = true;
if ((Previous.isOneOf(tok::comma, tok::semi) &&
!State.Stack.back().AvoidBinPacking) ||
Previous.Type == TT_BinaryOperator)
State.Stack.back().BreakBeforeParameter = false;
if (Previous.Type == TT_TemplateCloser && State.ParenLevel == 0)
State.Stack.back().BreakBeforeParameter = false;
if (!DryRun) {
unsigned NewLines = 1;
if (Current.is(tok::comment))
NewLines = std::max(
NewLines,
std::min(Current.NewlinesBefore, Style.MaxEmptyLinesToKeep + 1));
Whitespaces.replaceWhitespace(Current, NewLines, State.Column,
State.Column, Line.InPPDirective);
}
State.Stack.back().LastSpace = State.Column;
if (Current.isOneOf(tok::arrow, tok::period) &&
Current.Type != TT_DesignatedInitializerPeriod)
State.Stack.back().LastSpace += Current.CodePointCount;
State.StartOfLineLevel = State.ParenLevel;
State.LowestCallLevel = State.ParenLevel;
// Any break on this level means that the parent level has been broken
// and we need to avoid bin packing there.
for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i) {
State.Stack[i].BreakBeforeParameter = true;
}
const FormatToken *TokenBefore = Current.getPreviousNoneComment();
if (TokenBefore && !TokenBefore->isOneOf(tok::comma, tok::semi) &&
TokenBefore->Type != TT_TemplateCloser &&
TokenBefore->Type != TT_BinaryOperator && !TokenBefore->opensScope())
State.Stack.back().BreakBeforeParameter = true;
// If we break after {, we should also break before the corresponding }.
if (Previous.is(tok::l_brace))
State.Stack.back().BreakBeforeClosingBrace = true;
if (State.Stack.back().AvoidBinPacking) {
// If we are breaking after '(', '{', '<', this is not bin packing
// unless AllowAllParametersOfDeclarationOnNextLine is false.
if (!(Previous.isOneOf(tok::l_paren, tok::l_brace) ||
Previous.Type == TT_BinaryOperator) ||
(!Style.AllowAllParametersOfDeclarationOnNextLine &&
Line.MustBeDeclaration))
State.Stack.back().BreakBeforeParameter = true;
}
} else {
if (Current.is(tok::equal) &&
(RootToken->is(tok::kw_for) || State.ParenLevel == 0) &&
State.Stack.back().VariablePos == 0) {
State.Stack.back().VariablePos = State.Column;
// Move over * and & if they are bound to the variable name.
const FormatToken *Tok = &Previous;
while (Tok && State.Stack.back().VariablePos >= Tok->CodePointCount) {
State.Stack.back().VariablePos -= Tok->CodePointCount;
if (Tok->SpacesRequiredBefore != 0)
break;
Tok = Tok->Previous;
}
if (Previous.PartOfMultiVariableDeclStmt)
State.Stack.back().LastSpace = State.Stack.back().VariablePos;
}
unsigned Spaces = State.NextToken->SpacesRequiredBefore;
if (!DryRun)
Whitespaces.replaceWhitespace(Current, 0, Spaces,
State.Column + Spaces);
if (Current.Type == TT_ObjCSelectorName &&
State.Stack.back().ColonPos == 0) {
if (State.Stack.back().Indent + Current.LongestObjCSelectorName >
State.Column + Spaces + Current.CodePointCount)
State.Stack.back().ColonPos =
State.Stack.back().Indent + Current.LongestObjCSelectorName;
else
State.Stack.back().ColonPos =
State.Column + Spaces + Current.CodePointCount;
}
if (Previous.opensScope() && Previous.Type != TT_ObjCMethodExpr &&
Current.Type != TT_LineComment)
State.Stack.back().Indent = State.Column + Spaces;
if (Previous.is(tok::comma) && !Current.isTrailingComment() &&
State.Stack.back().AvoidBinPacking)
State.Stack.back().NoLineBreak = true;
State.Column += Spaces;
if (Current.is(tok::l_paren) && Previous.isOneOf(tok::kw_if, tok::kw_for))
// Treat the condition inside an if as if it was a second function
// parameter, i.e. let nested calls have an indent of 4.
State.Stack.back().LastSpace = State.Column + 1; // 1 is length of "(".
else if (Previous.is(tok::comma))
State.Stack.back().LastSpace = State.Column;
else if ((Previous.Type == TT_BinaryOperator ||
Previous.Type == TT_ConditionalExpr ||
Previous.Type == TT_CtorInitializerColon) &&
!(Previous.getPrecedence() == prec::Assignment &&
Current.FakeLParens.empty()))
// Always indent relative to the RHS of the expression unless this is a
// simple assignment without binary expression on the RHS.
State.Stack.back().LastSpace = State.Column;
else if (Previous.Type == TT_InheritanceColon)
State.Stack.back().Indent = State.Column;
else if (Previous.opensScope() && !Current.FakeLParens.empty())
// If this function has multiple parameters or a binary expression
// parameter, indent nested calls from the start of the first parameter.
State.Stack.back().LastSpace = State.Column;
}
return moveStateToNextToken(State, DryRun);
}
/// \brief Mark the next token as consumed in \p State and modify its stacks
/// accordingly.
unsigned moveStateToNextToken(LineState &State, bool DryRun) {
const FormatToken &Current = *State.NextToken;
assert(State.Stack.size());
if (Current.Type == TT_InheritanceColon)
State.Stack.back().AvoidBinPacking = true;
if (Current.is(tok::lessless) && State.Stack.back().FirstLessLess == 0)
State.Stack.back().FirstLessLess = State.Column;
if (Current.is(tok::question))
State.Stack.back().QuestionColumn = State.Column;
if (Current.isOneOf(tok::period, tok::arrow)) {
State.LowestCallLevel = std::min(State.LowestCallLevel, State.ParenLevel);
if (Line.Type == LT_BuilderTypeCall && State.ParenLevel == 0)
State.Stack.back().StartOfFunctionCall =
Current.LastInChainOfCalls ? 0
: State.Column + Current.CodePointCount;
}
if (Current.Type == TT_CtorInitializerColon) {
// Indent 2 from the column, so:
// SomeClass::SomeClass()
// : First(...), ...
// Next(...)
// ^ line up here.
State.Stack.back().Indent = State.Column + 2;
if (Style.ConstructorInitializerAllOnOneLineOrOnePerLine)
State.Stack.back().AvoidBinPacking = true;
State.Stack.back().BreakBeforeParameter = false;
}
// If return returns a binary expression, align after it.
if (Current.is(tok::kw_return) && !Current.FakeLParens.empty())
State.Stack.back().LastSpace = State.Column + 7;
// In ObjC method declaration we align on the ":" of parameters, but we need
// to ensure that we indent parameters on subsequent lines by at least 4.
if (Current.Type == TT_ObjCMethodSpecifier)
State.Stack.back().Indent += 4;
// Insert scopes created by fake parenthesis.
const FormatToken *Previous = Current.getPreviousNoneComment();
// Don't add extra indentation for the first fake parenthesis after
// 'return', assignements or opening <({[. The indentation for these cases
// is special cased.
bool SkipFirstExtraIndent =
Current.is(tok::kw_return) ||
(Previous && (Previous->opensScope() ||
Previous->getPrecedence() == prec::Assignment));
for (SmallVector<prec::Level, 4>::const_reverse_iterator
I = Current.FakeLParens.rbegin(),
E = Current.FakeLParens.rend();
I != E; ++I) {
ParenState NewParenState = State.Stack.back();
NewParenState.ForFakeParenthesis = true;
NewParenState.Indent =
std::max(std::max(State.Column, NewParenState.Indent),
State.Stack.back().LastSpace);
// Always indent conditional expressions. Never indent expression where
// the 'operator' is ',', ';' or an assignment (i.e. *I <=
// prec::Assignment) as those have different indentation rules. Indent
// other expression, unless the indentation needs to be skipped.
if (*I == prec::Conditional ||
(!SkipFirstExtraIndent && *I > prec::Assignment))
NewParenState.Indent += 4;
if (Previous && !Previous->opensScope())
NewParenState.BreakBeforeParameter = false;
State.Stack.push_back(NewParenState);
SkipFirstExtraIndent = false;
}
// If we encounter an opening (, [, { or <, we add a level to our stacks to
// prepare for the following tokens.
if (Current.opensScope()) {
unsigned NewIndent;
unsigned LastSpace = State.Stack.back().LastSpace;
bool AvoidBinPacking;
if (Current.is(tok::l_brace)) {
NewIndent = Style.IndentWidth + LastSpace;
const FormatToken *NextNoComment = Current.getNextNoneComment();
AvoidBinPacking = NextNoComment &&
NextNoComment->Type == TT_DesignatedInitializerPeriod;
} else {
NewIndent =
4 + std::max(LastSpace, State.Stack.back().StartOfFunctionCall);
AvoidBinPacking = !Style.BinPackParameters;
}
State.Stack.push_back(ParenState(NewIndent, LastSpace, AvoidBinPacking,
State.Stack.back().NoLineBreak));
++State.ParenLevel;
}
// If this '[' opens an ObjC call, determine whether all parameters fit into
// one line and put one per line if they don't.
if (Current.is(tok::l_square) && Current.Type == TT_ObjCMethodExpr &&
Current.MatchingParen != NULL) {
if (getLengthToMatchingParen(Current) + State.Column > getColumnLimit())
State.Stack.back().BreakBeforeParameter = true;
}
// If we encounter a closing ), ], } or >, we can remove a level from our
// stacks.
if (Current.isOneOf(tok::r_paren, tok::r_square) ||
(Current.is(tok::r_brace) && State.NextToken != RootToken) ||
State.NextToken->Type == TT_TemplateCloser) {
State.Stack.pop_back();
--State.ParenLevel;
}
// Remove scopes created by fake parenthesis.
for (unsigned i = 0, e = Current.FakeRParens; i != e; ++i) {
unsigned VariablePos = State.Stack.back().VariablePos;
State.Stack.pop_back();
State.Stack.back().VariablePos = VariablePos;
}
if (Current.is(tok::string_literal) && State.StartOfStringLiteral == 0) {
State.StartOfStringLiteral = State.Column;
} else if (!Current.isOneOf(tok::comment, tok::identifier, tok::hash,
tok::string_literal)) {
State.StartOfStringLiteral = 0;
}
State.Column += Current.CodePointCount;
State.NextToken = State.NextToken->Next;
return breakProtrudingToken(Current, State, DryRun);
}
/// \brief If the current token sticks out over the end of the line, break
/// it if possible.
///
/// \returns An extra penalty if a token was broken, otherwise 0.
///
/// The returned penalty will cover the cost of the additional line breaks and
/// column limit violation in all lines except for the last one. The penalty
/// for the column limit violation in the last line (and in single line
/// tokens) is handled in \c addNextStateToQueue.
unsigned breakProtrudingToken(const FormatToken &Current, LineState &State,
bool DryRun) {
llvm::OwningPtr<BreakableToken> Token;
unsigned StartColumn = State.Column - Current.CodePointCount;
unsigned OriginalStartColumn =
SourceMgr.getSpellingColumnNumber(Current.getStartOfNonWhitespace()) -
1;
if (Current.is(tok::string_literal) &&
Current.Type != TT_ImplicitStringLiteral) {
// Only break up default narrow strings.
if (!Current.TokenText.startswith("\""))
return 0;
Token.reset(new BreakableStringLiteral(Current, StartColumn,
Line.InPPDirective, Encoding));
} else if (Current.Type == TT_BlockComment) {
Token.reset(new BreakableBlockComment(
Style, Current, StartColumn, OriginalStartColumn, !Current.Previous,
Line.InPPDirective, Encoding));
} else if (Current.Type == TT_LineComment &&
(Current.Previous == NULL ||
Current.Previous->Type != TT_ImplicitStringLiteral)) {
Token.reset(new BreakableLineComment(Current, StartColumn,
Line.InPPDirective, Encoding));
} else {
return 0;
}
if (Current.UnbreakableTailLength >= getColumnLimit())
return 0;
unsigned RemainingSpace = getColumnLimit() - Current.UnbreakableTailLength;
bool BreakInserted = false;
unsigned Penalty = 0;
unsigned RemainingTokenColumns = 0;
for (unsigned LineIndex = 0, EndIndex = Token->getLineCount();
LineIndex != EndIndex; ++LineIndex) {
if (!DryRun)
Token->replaceWhitespaceBefore(LineIndex, Whitespaces);
unsigned TailOffset = 0;
RemainingTokenColumns = Token->getLineLengthAfterSplit(
LineIndex, TailOffset, StringRef::npos);
while (RemainingTokenColumns > RemainingSpace) {
BreakableToken::Split Split =
Token->getSplit(LineIndex, TailOffset, getColumnLimit());
if (Split.first == StringRef::npos) {
// The last line's penalty is handled in addNextStateToQueue().
if (LineIndex < EndIndex - 1)
Penalty += Style.PenaltyExcessCharacter *
(RemainingTokenColumns - RemainingSpace);
break;
}
assert(Split.first != 0);
unsigned NewRemainingTokenColumns = Token->getLineLengthAfterSplit(
LineIndex, TailOffset + Split.first + Split.second,
StringRef::npos);
assert(NewRemainingTokenColumns < RemainingTokenColumns);
if (!DryRun)
Token->insertBreak(LineIndex, TailOffset, Split, Whitespaces);
Penalty += Current.is(tok::string_literal) ? Style.PenaltyBreakString
: Style.PenaltyBreakComment;
unsigned ColumnsUsed =
Token->getLineLengthAfterSplit(LineIndex, TailOffset, Split.first);
if (ColumnsUsed > getColumnLimit()) {
Penalty +=
Style.PenaltyExcessCharacter * (ColumnsUsed - getColumnLimit());
}
TailOffset += Split.first + Split.second;
RemainingTokenColumns = NewRemainingTokenColumns;
BreakInserted = true;
}
}
State.Column = RemainingTokenColumns;
if (BreakInserted) {
// If we break the token inside a parameter list, we need to break before
// the next parameter on all levels, so that the next parameter is clearly
// visible. Line comments already introduce a break.
if (Current.Type != TT_LineComment) {
for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
State.Stack[i].BreakBeforeParameter = true;
}
State.Stack.back().LastSpace = StartColumn;
}
return Penalty;
}
unsigned getColumnLimit() {
// In preprocessor directives reserve two chars for trailing " \"
return Style.ColumnLimit - (Line.InPPDirective ? 2 : 0);
}
/// \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 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.
void analyzeSolutionSpace(LineState &InitialState) {
std::set<LineState> Seen;
// Insert start element into queue.
StateNode *Node =
new (Allocator.Allocate()) StateNode(InitialState, false, NULL);
Queue.push(QueueItem(OrderedPenalty(0, Count), Node));
++Count;
// While not empty, take first element and follow edges.
while (!Queue.empty()) {
unsigned Penalty = Queue.top().first.first;
StateNode *Node = Queue.top().second;
if (Node->State.NextToken == NULL) {
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;
addNextStateToQueue(Penalty, Node, /*NewLine=*/false);
addNextStateToQueue(Penalty, Node, /*NewLine=*/true);
}
if (Queue.empty())
// We were unable to find a solution, do nothing.
// FIXME: Add diagnostic?
return;
// Reconstruct the solution.
reconstructPath(InitialState, Queue.top().second);
DEBUG(llvm::dbgs() << "Total number of analyzed states: " << Count << "\n");
DEBUG(llvm::dbgs() << "---\n");
}
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) {
DEBUG({
if ((*I)->NewLine) {
llvm::dbgs() << "Penalty for splitting before "
<< (*I)->Previous->State.NextToken->Tok.getName() << ": "
<< (*I)->Previous->State.NextToken->SplitPenalty << "\n";
}
});
addTokenToState((*I)->NewLine, false, State);
}
}
/// \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) {
if (NewLine && !canBreak(PreviousNode->State))
return;
if (!NewLine && mustBreak(PreviousNode->State))
return;
if (NewLine)
Penalty += PreviousNode->State.NextToken->SplitPenalty;
StateNode *Node = new (Allocator.Allocate())
StateNode(PreviousNode->State, NewLine, PreviousNode);
Penalty += addTokenToState(NewLine, true, Node->State);
if (Node->State.Column > getColumnLimit()) {
unsigned ExcessCharacters = Node->State.Column - getColumnLimit();
Penalty += Style.PenaltyExcessCharacter * ExcessCharacters;
}
Queue.push(QueueItem(OrderedPenalty(Penalty, Count), Node));
++Count;
}
/// \brief Returns \c true, if a line break after \p State is allowed.
bool canBreak(const LineState &State) {
const FormatToken &Current = *State.NextToken;
const FormatToken &Previous = *Current.Previous;
assert(&Previous == Current.Previous);
if (!Current.CanBreakBefore &&
!(Current.is(tok::r_brace) &&
State.Stack.back().BreakBeforeClosingBrace))
return false;
// The opening "{" of a braced list has to be on the same line as the first
// element if it is nested in another braced init list or function call.
if (!Current.MustBreakBefore && Previous.is(tok::l_brace) &&
Previous.Previous &&
Previous.Previous->isOneOf(tok::l_brace, tok::l_paren, tok::comma))
return false;
// This prevents breaks like:
// ...
// SomeParameter, OtherParameter).DoSomething(
// ...
// As they hide "DoSomething" and are generally bad for readability.
if (Previous.opensScope() && State.LowestCallLevel < State.StartOfLineLevel)
return false;
return !State.Stack.back().NoLineBreak;
}
/// \brief Returns \c true, if a line break after \p State is mandatory.
bool mustBreak(const LineState &State) {
const FormatToken &Current = *State.NextToken;
const FormatToken &Previous = *Current.Previous;
if (Current.MustBreakBefore || Current.Type == TT_InlineASMColon)
return true;
if (Current.is(tok::r_brace) && State.Stack.back().BreakBeforeClosingBrace)
return true;
if (Previous.is(tok::semi) && State.LineContainsContinuedForLoopSection)
return true;
if ((Previous.isOneOf(tok::comma, tok::semi) || Current.is(tok::question) ||
Current.Type == TT_ConditionalExpr) &&
State.Stack.back().BreakBeforeParameter &&
!Current.isTrailingComment() &&
!Current.isOneOf(tok::r_paren, tok::r_brace))
return true;
// If we need to break somewhere inside the LHS of a binary expression, we
// should also break after the operator. Otherwise, the formatting would
// hide the operator precedence, e.g. in:
// if (aaaaaaaaaaaaaa ==
// bbbbbbbbbbbbbb && c) {..
// For comparisons, we only apply this rule, if the LHS is a binary
// expression itself as otherwise, the line breaks seem superfluous.
// We need special cases for ">>" which we have split into two ">" while
// lexing in order to make template parsing easier.
bool IsComparison = (Previous.getPrecedence() == prec::Relational ||
Previous.getPrecedence() == prec::Equality) &&
Previous.Previous &&
Previous.Previous->Type != TT_BinaryOperator; // For >>.
bool LHSIsBinaryExpr =
Previous.Previous && Previous.Previous->FakeRParens > 0;
if (Previous.Type == TT_BinaryOperator &&
(!IsComparison || LHSIsBinaryExpr) &&
Current.Type != TT_BinaryOperator && // For >>.
!Current.isTrailingComment() &&
!Previous.isOneOf(tok::lessless, tok::question) &&
Previous.getPrecedence() != prec::Assignment &&
State.Stack.back().BreakBeforeParameter)
return true;
// FIXME: Comparing LongestObjCSelectorName to 0 is a hacky way of finding
// out whether it is the first parameter. Clean this up.
if (Current.Type == TT_ObjCSelectorName &&
Current.LongestObjCSelectorName == 0 &&
State.Stack.back().BreakBeforeParameter)
return true;
if ((Current.Type == TT_CtorInitializerColon ||
(Previous.ClosesTemplateDeclaration && State.ParenLevel == 0)))
return true;
if (Current.Type == TT_StartOfName && Line.MightBeFunctionDecl &&
State.Stack.back().BreakBeforeParameter && State.ParenLevel == 0)
return true;
return false;
}
// Returns the total number of columns required for the remaining tokens.
unsigned getRemainingLength(const LineState &State) {
if (State.NextToken && State.NextToken->Previous)
return Line.Last->TotalLength - State.NextToken->Previous->TotalLength;
return 0;
}
FormatStyle Style;
SourceManager &SourceMgr;
const AnnotatedLine &Line;
const unsigned FirstIndent;
const FormatToken *RootToken;
WhitespaceManager &Whitespaces;
llvm::SpecificBumpPtrAllocator<StateNode> Allocator;
QueueType Queue;
// Increasing count of \c StateNode items we have created. This is used
// to create a deterministic order independent of the container.
unsigned Count;
encoding::Encoding Encoding;
};
class FormatTokenLexer {
public:
FormatTokenLexer(Lexer &Lex, SourceManager &SourceMgr,
encoding::Encoding Encoding)
: FormatTok(NULL), GreaterStashed(false), TrailingWhitespace(0), Lex(Lex),
SourceMgr(SourceMgr), IdentTable(Lex.getLangOpts()),
Encoding(Encoding) {
Lex.SetKeepWhitespaceMode(true);
}
ArrayRef<FormatToken *> lex() {
assert(Tokens.empty());
do {
Tokens.push_back(getNextToken());
} while (Tokens.back()->Tok.isNot(tok::eof));
return Tokens;
}
IdentifierTable &getIdentTable() { return IdentTable; }
private:
FormatToken *getNextToken() {
if (GreaterStashed) {
// Create a synthesized second '>' token.
Token Greater = FormatTok->Tok;
FormatTok = new (Allocator.Allocate()) FormatToken;
FormatTok->Tok = Greater;
SourceLocation GreaterLocation =
FormatTok->Tok.getLocation().getLocWithOffset(1);
FormatTok->WhitespaceRange =
SourceRange(GreaterLocation, GreaterLocation);
FormatTok->TokenText = ">";
FormatTok->CodePointCount = 1;
GreaterStashed = false;
return FormatTok;
}
FormatTok = new (Allocator.Allocate()) FormatToken;
Lex.LexFromRawLexer(FormatTok->Tok);
StringRef Text = rawTokenText(FormatTok->Tok);
SourceLocation WhitespaceStart =
FormatTok->Tok.getLocation().getLocWithOffset(-TrailingWhitespace);
if (SourceMgr.getFileOffset(WhitespaceStart) == 0)
FormatTok->IsFirst = true;
// Consume and record whitespace until we find a significant token.
unsigned WhitespaceLength = TrailingWhitespace;
while (FormatTok->Tok.is(tok::unknown)) {
unsigned Newlines = Text.count('\n');
if (Newlines > 0)
FormatTok->LastNewlineOffset = WhitespaceLength + Text.rfind('\n') + 1;
FormatTok->NewlinesBefore += Newlines;
unsigned EscapedNewlines = Text.count("\\\n");
FormatTok->HasUnescapedNewline |= EscapedNewlines != Newlines;
WhitespaceLength += FormatTok->Tok.getLength();
Lex.LexFromRawLexer(FormatTok->Tok);
Text = rawTokenText(FormatTok->Tok);
}
// In case the token starts with escaped newlines, we want to
// take them into account as whitespace - this pattern is quite frequent
// in macro definitions.
// FIXME: What do we want to do with other escaped spaces, and escaped
// spaces or newlines in the middle of tokens?
// FIXME: Add a more explicit test.
while (Text.size() > 1 && Text[0] == '\\' && Text[1] == '\n') {
// FIXME: ++FormatTok->NewlinesBefore is missing...
WhitespaceLength += 2;
Text = Text.substr(2);
}
TrailingWhitespace = 0;
if (FormatTok->Tok.is(tok::comment)) {
StringRef UntrimmedText = Text;
Text = Text.rtrim();
TrailingWhitespace = UntrimmedText.size() - Text.size();
} else if (FormatTok->Tok.is(tok::raw_identifier)) {
IdentifierInfo &Info = IdentTable.get(Text);
FormatTok->Tok.setIdentifierInfo(&Info);
FormatTok->Tok.setKind(Info.getTokenID());
} else if (FormatTok->Tok.is(tok::greatergreater)) {
FormatTok->Tok.setKind(tok::greater);
Text = Text.substr(0, 1);
GreaterStashed = true;
}
// Now FormatTok is the next non-whitespace token.
FormatTok->TokenText = Text;
FormatTok->CodePointCount = encoding::getCodePointCount(Text, Encoding);
FormatTok->WhitespaceRange = SourceRange(
WhitespaceStart, WhitespaceStart.getLocWithOffset(WhitespaceLength));
return FormatTok;
}
FormatToken *FormatTok;
bool GreaterStashed;
unsigned TrailingWhitespace;
Lexer &Lex;
SourceManager &SourceMgr;
IdentifierTable IdentTable;
encoding::Encoding Encoding;
llvm::SpecificBumpPtrAllocator<FormatToken> Allocator;
SmallVector<FormatToken *, 16> Tokens;
/// Returns the text of \c FormatTok.
StringRef rawTokenText(Token &Tok) {
return StringRef(SourceMgr.getCharacterData(Tok.getLocation()),
Tok.getLength());
}
};
class Formatter : public UnwrappedLineConsumer {
public:
Formatter(const FormatStyle &Style, Lexer &Lex, SourceManager &SourceMgr,
const std::vector<CharSourceRange> &Ranges)
: Style(Style), Lex(Lex), SourceMgr(SourceMgr),
Whitespaces(SourceMgr, Style), Ranges(Ranges),
Encoding(encoding::detectEncoding(Lex.getBuffer())) {
DEBUG(llvm::dbgs()
<< "File encoding: "
<< (Encoding == encoding::Encoding_UTF8 ? "UTF8" : "unknown")
<< "\n");
}
virtual ~Formatter() {}
tooling::Replacements format() {
FormatTokenLexer Tokens(Lex, SourceMgr, Encoding);
UnwrappedLineParser Parser(Style, Tokens.lex(), *this);
bool StructuralError = Parser.parse();
TokenAnnotator Annotator(Style, Tokens.getIdentTable().get("in"));
for (unsigned i = 0, e = AnnotatedLines.size(); i != e; ++i) {
Annotator.annotate(AnnotatedLines[i]);
}
deriveLocalStyle();
for (unsigned i = 0, e = AnnotatedLines.size(); i != e; ++i) {
Annotator.calculateFormattingInformation(AnnotatedLines[i]);
}
// Adapt level to the next line if this is a comment.
// FIXME: Can/should this be done in the UnwrappedLineParser?
const AnnotatedLine *NextNoneCommentLine = NULL;
for (unsigned i = AnnotatedLines.size() - 1; i > 0; --i) {
if (NextNoneCommentLine && AnnotatedLines[i].First->is(tok::comment) &&
!AnnotatedLines[i].First->Next)
AnnotatedLines[i].Level = NextNoneCommentLine->Level;
else
NextNoneCommentLine =
AnnotatedLines[i].First->isNot(tok::r_brace) ? &AnnotatedLines[i]
: NULL;
}
std::vector<int> IndentForLevel;
bool PreviousLineWasTouched = false;
const FormatToken *PreviousLineLastToken = 0;
bool FormatPPDirective = false;
for (std::vector<AnnotatedLine>::iterator I = AnnotatedLines.begin(),
E = AnnotatedLines.end();
I != E; ++I) {
const AnnotatedLine &TheLine = *I;
const FormatToken *FirstTok = TheLine.First;
int Offset = getIndentOffset(*TheLine.First);
// Check whether this line is part of a formatted preprocessor directive.
if (FirstTok->HasUnescapedNewline)
FormatPPDirective = false;
if (!FormatPPDirective && TheLine.InPPDirective &&
(touchesLine(TheLine) || touchesPPDirective(I + 1, E)))
FormatPPDirective = true;
// Determine indent and try to merge multiple unwrapped lines.
while (IndentForLevel.size() <= TheLine.Level)
IndentForLevel.push_back(-1);
IndentForLevel.resize(TheLine.Level + 1);
unsigned Indent = getIndent(IndentForLevel, TheLine.Level);
if (static_cast<int>(Indent) + Offset >= 0)
Indent += Offset;
tryFitMultipleLinesInOne(Indent, I, E);
bool WasMoved = PreviousLineWasTouched && FirstTok->NewlinesBefore == 0;
if (TheLine.First->is(tok::eof)) {
if (PreviousLineWasTouched) {
unsigned NewLines = std::min(FirstTok->NewlinesBefore, 1u);
Whitespaces.replaceWhitespace(*TheLine.First, NewLines, /*Indent*/ 0,
/*TargetColumn*/ 0);
}
} else if (TheLine.Type != LT_Invalid &&
(WasMoved || FormatPPDirective || touchesLine(TheLine))) {
unsigned LevelIndent = getIndent(IndentForLevel, TheLine.Level);
if (FirstTok->WhitespaceRange.isValid() &&
// Insert a break even if there is a structural error in case where
// we break apart a line consisting of multiple unwrapped lines.
(FirstTok->NewlinesBefore == 0 || !StructuralError)) {
formatFirstToken(*TheLine.First, PreviousLineLastToken, Indent,
TheLine.InPPDirective);
} else {
Indent = LevelIndent =
SourceMgr.getSpellingColumnNumber(FirstTok->Tok.getLocation()) -
1;
}
UnwrappedLineFormatter Formatter(Style, SourceMgr, TheLine, Indent,
TheLine.First, Whitespaces, Encoding);
Formatter.format(I + 1 != E ? &*(I + 1) : NULL);
IndentForLevel[TheLine.Level] = LevelIndent;
PreviousLineWasTouched = true;
} else {
// Format the first token if necessary, and notify the WhitespaceManager
// about the unchanged whitespace.
for (const FormatToken *Tok = TheLine.First; Tok != NULL;
Tok = Tok->Next) {
if (Tok == TheLine.First &&
(Tok->NewlinesBefore > 0 || Tok->IsFirst)) {
unsigned LevelIndent =
SourceMgr.getSpellingColumnNumber(Tok->Tok.getLocation()) - 1;
// Remove trailing whitespace of the previous line if it was
// touched.
if (PreviousLineWasTouched || touchesEmptyLineBefore(TheLine)) {
formatFirstToken(*Tok, PreviousLineLastToken, LevelIndent,
TheLine.InPPDirective);
} else {
Whitespaces.addUntouchableToken(*Tok, TheLine.InPPDirective);
}
if (static_cast<int>(LevelIndent) - Offset >= 0)
LevelIndent -= Offset;
if (Tok->isNot(tok::comment))
IndentForLevel[TheLine.Level] = LevelIndent;
} else {
Whitespaces.addUntouchableToken(*Tok, TheLine.InPPDirective);
}
}
// If we did not reformat this unwrapped line, the column at the end of
// the last token is unchanged - thus, we can calculate the end of the
// last token.
PreviousLineWasTouched = false;
}
PreviousLineLastToken = I->Last;
}
return Whitespaces.generateReplacements();
}
private:
void deriveLocalStyle() {
unsigned CountBoundToVariable = 0;
unsigned CountBoundToType = 0;
bool HasCpp03IncompatibleFormat = false;
for (unsigned i = 0, e = AnnotatedLines.size(); i != e; ++i) {
if (!AnnotatedLines[i].First->Next)
continue;
FormatToken *Tok = AnnotatedLines[i].First->Next;
while (Tok->Next) {
if (Tok->Type == TT_PointerOrReference) {
bool SpacesBefore =
Tok->WhitespaceRange.getBegin() != Tok->WhitespaceRange.getEnd();
bool SpacesAfter = Tok->Next->WhitespaceRange.getBegin() !=
Tok->Next->WhitespaceRange.getEnd();
if (SpacesBefore && !SpacesAfter)
++CountBoundToVariable;
else if (!SpacesBefore && SpacesAfter)
++CountBoundToType;
}
if (Tok->Type == TT_TemplateCloser &&
Tok->Previous->Type == TT_TemplateCloser &&
Tok->WhitespaceRange.getBegin() == Tok->WhitespaceRange.getEnd())
HasCpp03IncompatibleFormat = true;
Tok = Tok->Next;
}
}
if (Style.DerivePointerBinding) {
if (CountBoundToType > CountBoundToVariable)
Style.PointerBindsToType = true;
else if (CountBoundToType < CountBoundToVariable)
Style.PointerBindsToType = false;
}
if (Style.Standard == FormatStyle::LS_Auto) {
Style.Standard = HasCpp03IncompatibleFormat ? FormatStyle::LS_Cpp11
: FormatStyle::LS_Cpp03;
}
}
/// \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(const std::vector<int> IndentForLevel, unsigned Level) {
if (IndentForLevel[Level] != -1)
return IndentForLevel[Level];
if (Level == 0)
return 0;
return getIndent(IndentForLevel, Level - 1) + Style.IndentWidth;
}
/// \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 (RootToken.isAccessSpecifier(false) || RootToken.isObjCAccessSpecifier())
return Style.AccessModifierOffset;
return 0;
}
/// \brief Tries to merge lines into one.
///
/// This will change \c Line and \c AnnotatedLine to contain the merged line,
/// if possible; note that \c I will be incremented when lines are merged.
void tryFitMultipleLinesInOne(unsigned Indent,
std::vector<AnnotatedLine>::iterator &I,
std::vector<AnnotatedLine>::iterator E) {
// We can never merge stuff if there are trailing line comments.
if (I->Last->Type == TT_LineComment)
return;
unsigned Limit = 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 = I->Last->TotalLength > Limit ? 0 : Limit - I->Last->TotalLength;
if (I + 1 == E || (I + 1)->Type == LT_Invalid)
return;
if (I->Last->is(tok::l_brace)) {
tryMergeSimpleBlock(I, E, Limit);
} else if (Style.AllowShortIfStatementsOnASingleLine &&
I->First->is(tok::kw_if)) {
tryMergeSimpleControlStatement(I, E, Limit);
} else if (Style.AllowShortLoopsOnASingleLine &&
I->First->isOneOf(tok::kw_for, tok::kw_while)) {
tryMergeSimpleControlStatement(I, E, Limit);
} else if (I->InPPDirective &&
(I->First->HasUnescapedNewline || I->First->IsFirst)) {
tryMergeSimplePPDirective(I, E, Limit);
}
}
void tryMergeSimplePPDirective(std::vector<AnnotatedLine>::iterator &I,
std::vector<AnnotatedLine>::iterator E,
unsigned Limit) {
if (Limit == 0)
return;
AnnotatedLine &Line = *I;
if (!(I + 1)->InPPDirective || (I + 1)->First->HasUnescapedNewline)
return;
if (I + 2 != E && (I + 2)->InPPDirective &&
!(I + 2)->First->HasUnescapedNewline)
return;
if (1 + (I + 1)->Last->TotalLength > Limit)
return;
join(Line, *(++I));
}
void tryMergeSimpleControlStatement(std::vector<AnnotatedLine>::iterator &I,
std::vector<AnnotatedLine>::iterator E,
unsigned Limit) {
if (Limit == 0)
return;
if ((I + 1)->InPPDirective != I->InPPDirective ||
((I + 1)->InPPDirective && (I + 1)->First->HasUnescapedNewline))
return;
AnnotatedLine &Line = *I;
if (Line.Last->isNot(tok::r_paren))
return;
if (1 + (I + 1)->Last->TotalLength > Limit)
return;
if ((I + 1)->First->isOneOf(tok::semi, tok::kw_if, tok::kw_for,
tok::kw_while) ||
(I + 1)->First->Type == TT_LineComment)
return;
// 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;
join(Line, *(++I));
}
void tryMergeSimpleBlock(std::vector<AnnotatedLine>::iterator &I,
std::vector<AnnotatedLine>::iterator E,
unsigned Limit) {
// No merging if the brace already is on the next line.
if (Style.BreakBeforeBraces != FormatStyle::BS_Attach)
return;
// First, check that the current line allows merging. This is the case if
// we're not in a control flow statement and the last token is an opening
// brace.
AnnotatedLine &Line = *I;
if (Line.First->isOneOf(tok::kw_if, tok::kw_while, tok::kw_do, tok::r_brace,
tok::kw_else, tok::kw_try, tok::kw_catch,
tok::kw_for,
// This gets rid of all ObjC @ keywords and methods.
tok::at, tok::minus, tok::plus))
return;
FormatToken *Tok = (I + 1)->First;
if (Tok->is(tok::r_brace) && !Tok->MustBreakBefore &&
(Tok->getNextNoneComment() == NULL ||
Tok->getNextNoneComment()->is(tok::semi))) {
// We merge empty blocks even if the line exceeds the column limit.
Tok->SpacesRequiredBefore = 0;
Tok->CanBreakBefore = true;
join(Line, *(I + 1));
I += 1;
} else if (Limit != 0 && Line.First->isNot(tok::kw_namespace)) {
// Check that we still have three lines and they fit into the limit.
if (I + 2 == E || (I + 2)->Type == LT_Invalid ||
!nextTwoLinesFitInto(I, Limit))
return;
// 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->Type == TT_LineComment || Tok->MustBreakBefore)
return;
do {
if (Tok->isOneOf(tok::l_brace, tok::r_brace))
return;
Tok = Tok->Next;
} while (Tok != NULL);
// Last, check that the third line contains a single closing brace.
Tok = (I + 2)->First;
if (Tok->getNextNoneComment() != NULL || Tok->isNot(tok::r_brace) ||
Tok->MustBreakBefore)
return;
join(Line, *(I + 1));
join(Line, *(I + 2));
I += 2;
}
}
bool nextTwoLinesFitInto(std::vector<AnnotatedLine>::iterator I,
unsigned Limit) {
return 1 + (I + 1)->Last->TotalLength + 1 + (I + 2)->Last->TotalLength <=
Limit;
}
void join(AnnotatedLine &A, const AnnotatedLine &B) {
assert(!A.Last->Next);
assert(!B.First->Previous);
A.Last->Next = B.First;
B.First->Previous = A.Last;
unsigned LengthA = A.Last->TotalLength + B.First->SpacesRequiredBefore;
for (FormatToken *Tok = B.First; Tok; Tok = Tok->Next) {
Tok->TotalLength += LengthA;
A.Last = Tok;
}
}
bool touchesRanges(const CharSourceRange &Range) {
for (unsigned i = 0, e = Ranges.size(); i != e; ++i) {
if (!SourceMgr.isBeforeInTranslationUnit(Range.getEnd(),
Ranges[i].getBegin()) &&
!SourceMgr.isBeforeInTranslationUnit(Ranges[i].getEnd(),
Range.getBegin()))
return true;
}
return false;
}
bool touchesLine(const AnnotatedLine &TheLine) {
const FormatToken *First = TheLine.First;
const FormatToken *Last = TheLine.Last;
CharSourceRange LineRange = CharSourceRange::getCharRange(
First->WhitespaceRange.getBegin().getLocWithOffset(
First->LastNewlineOffset),
Last->Tok.getLocation().getLocWithOffset(Last->TokenText.size() - 1));
return touchesRanges(LineRange);
}
bool touchesPPDirective(std::vector<AnnotatedLine>::iterator I,
std::vector<AnnotatedLine>::iterator E) {
for (; I != E; ++I) {
if (I->First->HasUnescapedNewline)
return false;
if (touchesLine(*I))
return true;
}
return false;
}
bool touchesEmptyLineBefore(const AnnotatedLine &TheLine) {
const FormatToken *First = TheLine.First;
CharSourceRange LineRange = CharSourceRange::getCharRange(
First->WhitespaceRange.getBegin(),
First->WhitespaceRange.getBegin().getLocWithOffset(
First->LastNewlineOffset));
return touchesRanges(LineRange);
}
virtual void consumeUnwrappedLine(const UnwrappedLine &TheLine) {
AnnotatedLines.push_back(AnnotatedLine(TheLine));
}
/// \brief Add a new line and the required indent before the first Token
/// of the \c UnwrappedLine if there was no structural parsing error.
/// Returns the indent level of the \c UnwrappedLine.
void formatFirstToken(const FormatToken &RootToken,
const FormatToken *PreviousToken, 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;
// Insert extra new line before access specifiers.
if (PreviousToken && PreviousToken->isOneOf(tok::semi, tok::r_brace) &&
RootToken.isAccessSpecifier() && RootToken.NewlinesBefore == 1)
++Newlines;
Whitespaces.replaceWhitespace(
RootToken, Newlines, Indent, Indent,
InPPDirective && !RootToken.HasUnescapedNewline);
}
FormatStyle Style;
Lexer &Lex;
SourceManager &SourceMgr;
WhitespaceManager Whitespaces;
std::vector<CharSourceRange> Ranges;
std::vector<AnnotatedLine> AnnotatedLines;
encoding::Encoding Encoding;
};
} // end anonymous namespace
tooling::Replacements reformat(const FormatStyle &Style, Lexer &Lex,
SourceManager &SourceMgr,
std::vector<CharSourceRange> Ranges) {
Formatter formatter(Style, Lex, SourceMgr, Ranges);
return formatter.format();
}
tooling::Replacements reformat(const FormatStyle &Style, StringRef Code,
std::vector<tooling::Range> Ranges,
StringRef FileName) {
FileManager Files((FileSystemOptions()));
DiagnosticsEngine Diagnostics(
IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs),
new DiagnosticOptions);
SourceManager SourceMgr(Diagnostics, Files);
llvm::MemoryBuffer *Buf = llvm::MemoryBuffer::getMemBuffer(Code, FileName);
const clang::FileEntry *Entry =
Files.getVirtualFile(FileName, Buf->getBufferSize(), 0);
SourceMgr.overrideFileContents(Entry, Buf);
FileID ID =
SourceMgr.createFileID(Entry, SourceLocation(), clang::SrcMgr::C_User);
Lexer Lex(ID, SourceMgr.getBuffer(ID), SourceMgr,
getFormattingLangOpts(Style.Standard));
SourceLocation StartOfFile = SourceMgr.getLocForStartOfFile(ID);
std::vector<CharSourceRange> CharRanges;
for (unsigned i = 0, e = Ranges.size(); i != e; ++i) {
SourceLocation Start = StartOfFile.getLocWithOffset(Ranges[i].getOffset());
SourceLocation End = Start.getLocWithOffset(Ranges[i].getLength());
CharRanges.push_back(CharSourceRange::getCharRange(Start, End));
}
return reformat(Style, Lex, SourceMgr, CharRanges);
}
LangOptions getFormattingLangOpts(FormatStyle::LanguageStandard Standard) {
LangOptions LangOpts;
LangOpts.CPlusPlus = 1;
LangOpts.CPlusPlus11 = Standard == FormatStyle::LS_Cpp03 ? 0 : 1;
LangOpts.LineComment = 1;
LangOpts.Bool = 1;
LangOpts.ObjC1 = 1;
LangOpts.ObjC2 = 1;
return LangOpts;
}
} // namespace format
} // namespace clang
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