path: root/lib/Format/Format.cpp

//===--- 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 "UnwrappedLineParser.h"
#include "clang/Basic/OperatorPrecedence.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Lex/Lexer.h"
#include <string>

namespace clang {
namespace format {

// FIXME: Move somewhere sane.
struct TokenAnnotation {
  enum TokenType {
    TT_Unknown,
    TT_TemplateOpener,
    TT_TemplateCloser,
    TT_BinaryOperator,
    TT_UnaryOperator,
    TT_TrailingUnaryOperator,
    TT_OverloadedOperator,
    TT_PointerOrReference,
    TT_ConditionalExpr,
    TT_CtorInitializerColon,
    TT_LineComment,
    TT_BlockComment,
    TT_DirectorySeparator,
    TT_ObjCMethodSpecifier
  };

  TokenType Type;

  bool SpaceRequiredBefore;
  bool CanBreakBefore;
  bool MustBreakBefore;

  bool ClosesTemplateDeclaration;
};

static prec::Level getPrecedence(const FormatToken &Tok) {
  return getBinOpPrecedence(Tok.Tok.getKind(), true, true);
}

using llvm::MutableArrayRef;

FormatStyle getLLVMStyle() {
  FormatStyle LLVMStyle;
  LLVMStyle.ColumnLimit = 80;
  LLVMStyle.MaxEmptyLinesToKeep = 1;
  LLVMStyle.PointerAndReferenceBindToType = false;
  LLVMStyle.AccessModifierOffset = -2;
  LLVMStyle.SplitTemplateClosingGreater = true;
  LLVMStyle.IndentCaseLabels = false;
  return LLVMStyle;
}

FormatStyle getGoogleStyle() {
  FormatStyle GoogleStyle;
  GoogleStyle.ColumnLimit = 80;
  GoogleStyle.MaxEmptyLinesToKeep = 1;
  GoogleStyle.PointerAndReferenceBindToType = true;
  GoogleStyle.AccessModifierOffset = -1;
  GoogleStyle.SplitTemplateClosingGreater = false;
  GoogleStyle.IndentCaseLabels = true;
  return GoogleStyle;
}

struct OptimizationParameters {
  unsigned PenaltyIndentLevel;
  unsigned PenaltyLevelDecrease;
};

class UnwrappedLineFormatter {
public:
  UnwrappedLineFormatter(const FormatStyle &Style, SourceManager &SourceMgr,
                         const UnwrappedLine &Line,
                         unsigned PreviousEndOfLineColumn,
                         const std::vector<TokenAnnotation> &Annotations,
                         tooling::Replacements &Replaces, bool StructuralError)
      : Style(Style), SourceMgr(SourceMgr), Line(Line),
        PreviousEndOfLineColumn(PreviousEndOfLineColumn),
        Annotations(Annotations), Replaces(Replaces),
        StructuralError(StructuralError) {
    Parameters.PenaltyIndentLevel = 15;
    Parameters.PenaltyLevelDecrease = 30;
  }

  /// \brief Formats an \c UnwrappedLine.
  ///
  /// \returns The column after the last token in the last line of the
  /// \c UnwrappedLine.
  unsigned format() {
    // Format first token and initialize indent.
    unsigned Indent = formatFirstToken();

    // Initialize state dependent on indent.
    IndentState State;
    State.Column = Indent;
    State.ConsumedTokens = 0;
    State.Indent.push_back(Indent + 4);
    State.LastSpace.push_back(Indent);
    State.FirstLessLess.push_back(0);
    State.ForLoopVariablePos = 0;
    State.LineContainsContinuedForLoopSection = false;
    State.StartOfLineLevel = 1;

    // The first t