blob: 189b1aefa03f011c13face2301231574daf401ec [file] [log] [blame]
//===--- WhitespaceManager.h - Format C++ code ------------------*- C++ -*-===//
// The LLVM Compiler Infrastructure
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
/// \file
/// \brief WhitespaceManager class manages whitespace around tokens and their
/// replacements.
#include "TokenAnnotator.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Format/Format.h"
#include <string>
namespace clang {
namespace format {
/// \brief Manages the whitespaces around tokens and their replacements.
/// This includes special handling for certain constructs, e.g. the alignment of
/// trailing line comments.
/// To guarantee correctness of alignment operations, the \c WhitespaceManager
/// must be informed about every token in the source file; for each token, there
/// must be exactly one call to either \c replaceWhitespace or
/// \c addUntouchableToken.
/// There may be multiple calls to \c breakToken for a given token.
class WhitespaceManager {
WhitespaceManager(SourceManager &SourceMgr, const FormatStyle &Style,
bool UseCRLF)
: SourceMgr(SourceMgr), Style(Style), UseCRLF(UseCRLF) {}
/// \brief Prepares the \c WhitespaceManager for another run.
void reset();
/// \brief Replaces the whitespace in front of \p Tok. Only call once for
/// each \c AnnotatedToken.
void replaceWhitespace(FormatToken &Tok, unsigned Newlines,
unsigned IndentLevel, unsigned Spaces,
unsigned StartOfTokenColumn,
bool InPPDirective = false);
/// \brief Adds information about an unchangeable token's whitespace.
/// Needs to be called for every token for which \c replaceWhitespace
/// was not called.
void addUntouchableToken(const FormatToken &Tok, bool InPPDirective);
/// \brief Inserts or replaces whitespace in the middle of a token.
/// Inserts \p PreviousPostfix, \p Newlines, \p Spaces and \p CurrentPrefix
/// (in this order) at \p Offset inside \p Tok, replacing \p ReplaceChars
/// characters.
/// Note: \p Spaces can be negative to retain information about initial
/// relative column offset between a line of a block comment and the start of
/// the comment. This negative offset may be compensated by trailing comment
/// alignment here. In all other cases negative \p Spaces will be truncated to
/// 0.
/// When \p InPPDirective is true, escaped newlines are inserted. \p Spaces is
/// used to align backslashes correctly.
void replaceWhitespaceInToken(const FormatToken &Tok, unsigned Offset,
unsigned ReplaceChars,
StringRef PreviousPostfix,
StringRef CurrentPrefix, bool InPPDirective,
unsigned Newlines, unsigned IndentLevel,
int Spaces);
/// \brief Returns all the \c Replacements created during formatting.
const tooling::Replacements &generateReplacements();
/// \brief Represents a change before a token, a break inside a token,
/// or the layout of an unchanged token (or whitespace within).
struct Change {
/// \brief Functor to sort changes in original source order.
class IsBeforeInFile {
IsBeforeInFile(const SourceManager &SourceMgr) : SourceMgr(SourceMgr) {}
bool operator()(const Change &C1, const Change &C2) const;
const SourceManager &SourceMgr;
Change() {}
/// \brief Creates a \c Change.
/// The generated \c Change will replace the characters at
/// \p OriginalWhitespaceRange with a concatenation of
/// \p PreviousLinePostfix, \p NewlinesBefore line breaks, \p Spaces spaces
/// and \p CurrentLinePrefix.
/// \p StartOfTokenColumn and \p InPPDirective will be used to lay out
/// trailing comments and escaped newlines.
Change(bool CreateReplacement, const SourceRange &OriginalWhitespaceRange,
unsigned IndentLevel, int Spaces, unsigned StartOfTokenColumn,
unsigned NewlinesBefore, StringRef PreviousLinePostfix,
StringRef CurrentLinePrefix, tok::TokenKind Kind,
bool ContinuesPPDirective);
bool CreateReplacement;
// Changes might be in the middle of a token, so we cannot just keep the
// FormatToken around to query its information.
SourceRange OriginalWhitespaceRange;
unsigned StartOfTokenColumn;
unsigned NewlinesBefore;
std::string PreviousLinePostfix;
std::string CurrentLinePrefix;
// The kind of the token whose whitespace this change replaces, or in which
// this change inserts whitespace.
// FIXME: Currently this is not set correctly for breaks inside comments, as
// the \c BreakableToken is still doing its own alignment.
tok::TokenKind Kind;
bool ContinuesPPDirective;
// The number of nested blocks the token is in. This is used to add tabs
// only for the indentation, and not for alignment, when
// UseTab = US_ForIndentation.
unsigned IndentLevel;
// The number of spaces in front of the token or broken part of the token.
// This will be adapted when aligning tokens.
// Can be negative to retain information about the initial relative offset
// of the lines in a block comment. This is used when aligning trailing
// comments. Uncompensated negative offset is truncated to 0.
int Spaces;
// \c IsTrailingComment, \c TokenLength, \c PreviousEndOfTokenColumn and
// \c EscapedNewlineColumn will be calculated in
// \c calculateLineBreakInformation.
bool IsTrailingComment;
unsigned TokenLength;
unsigned PreviousEndOfTokenColumn;
unsigned EscapedNewlineColumn;
// These fields are used to retain correct relative line indentation in a
// block comment when aligning trailing comments.
// If this Change represents a continuation of a block comment,
// \c StartOfBlockComment is pointer to the first Change in the block
// comment. \c IndentationOffset is a relative column offset to this
// change, so that the correct column can be reconstructed at the end of
// the alignment process.
const Change *StartOfBlockComment;
int IndentationOffset;
/// \brief Calculate \c IsTrailingComment, \c TokenLength for the last tokens
/// or token parts in a line and \c PreviousEndOfTokenColumn and
/// \c EscapedNewlineColumn for the first tokens or token parts in a line.
void calculateLineBreakInformation();
/// \brief Align trailing comments over all \c Changes.
void alignTrailingComments();
/// \brief Align trailing comments from change \p Start to change \p End at
/// the specified \p Column.
void alignTrailingComments(unsigned Start, unsigned End, unsigned Column);
/// \brief Align escaped newlines over all \c Changes.
void alignEscapedNewlines();
/// \brief Align escaped newlines from change \p Start to change \p End at
/// the specified \p Column.
void alignEscapedNewlines(unsigned Start, unsigned End, unsigned Column);
/// \brief Fill \c Replaces with the replacements for all effective changes.
void generateChanges();
/// \brief Stores \p Text as the replacement for the whitespace in \p Range.
void storeReplacement(const SourceRange &Range, StringRef Text);
void appendNewlineText(std::string &Text, unsigned Newlines);
void appendNewlineText(std::string &Text, unsigned Newlines,
unsigned PreviousEndOfTokenColumn,
unsigned EscapedNewlineColumn);
void appendIndentText(std::string &Text, unsigned IndentLevel,
unsigned Spaces, unsigned WhitespaceStartColumn);
SmallVector<Change, 16> Changes;
SourceManager &SourceMgr;
tooling::Replacements Replaces;
const FormatStyle &Style;
bool UseCRLF;
} // namespace format
} // namespace clang