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//===--- UnwrappedLineParser.h - Format C++ code ----------------*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
/// \file
/// This file contains the declaration of the UnwrappedLineParser,
/// which turns a stream of tokens into UnwrappedLines.
#include "FormatToken.h"
#include "clang/Basic/IdentifierTable.h"
#include "clang/Format/Format.h"
#include "llvm/Support/Regex.h"
#include <stack>
#include <vector>
namespace clang {
namespace format {
struct UnwrappedLineNode;
/// An unwrapped line is a sequence of \c Token, that we would like to
/// put on a single line if there was no column limit.
/// This is used as a main interface between the \c UnwrappedLineParser and the
/// \c UnwrappedLineFormatter. The key property is that changing the formatting
/// within an unwrapped line does not affect any other unwrapped lines.
struct UnwrappedLine {
/// The \c Tokens comprising this \c UnwrappedLine.
std::vector<UnwrappedLineNode> Tokens;
/// The indent level of the \c UnwrappedLine.
unsigned Level;
/// Whether this \c UnwrappedLine is part of a preprocessor directive.
bool InPPDirective;
bool MustBeDeclaration;
/// If this \c UnwrappedLine closes a block in a sequence of lines,
/// \c MatchingOpeningBlockLineIndex stores the index of the corresponding
/// opening line. Otherwise, \c MatchingOpeningBlockLineIndex must be
/// \c kInvalidIndex.
size_t MatchingOpeningBlockLineIndex = kInvalidIndex;
/// If this \c UnwrappedLine opens a block, stores the index of the
/// line with the corresponding closing brace.
size_t MatchingClosingBlockLineIndex = kInvalidIndex;
static const size_t kInvalidIndex = -1;
unsigned FirstStartColumn = 0;
class UnwrappedLineConsumer {
virtual ~UnwrappedLineConsumer() {}
virtual void consumeUnwrappedLine(const UnwrappedLine &Line) = 0;
virtual void finishRun() = 0;
class FormatTokenSource;
class UnwrappedLineParser {
UnwrappedLineParser(const FormatStyle &Style,
const AdditionalKeywords &Keywords,
unsigned FirstStartColumn, ArrayRef<FormatToken *> Tokens,
UnwrappedLineConsumer &Callback);
void parse();
void reset();
void parseFile();
void parseLevel(bool HasOpeningBrace);
void parseBlock(bool MustBeDeclaration = false, unsigned AddLevels = 1u,
bool MunchSemi = true,
bool UnindentWhitesmithsBraces = false);
void parseChildBlock();
void parsePPDirective();
void parsePPDefine();
void parsePPIf(bool IfDef);
void parsePPElIf();
void parsePPElse();
void parsePPEndIf();
void parsePPUnknown();
void readTokenWithJavaScriptASI();
void parseStructuralElement(bool IsTopLevel = false);
bool tryToParseBracedList();
bool parseBracedList(bool ContinueOnSemicolons = false, bool IsEnum = false,
tok::TokenKind ClosingBraceKind = tok::r_brace);
void parseParens();
void parseSquare(bool LambdaIntroducer = false);
void parseIfThenElse();
void parseTryCatch();
void parseForOrWhileLoop();
void parseDoWhile();
void parseLabel(bool LeftAlignLabel = false);
void parseCaseLabel();
void parseSwitch();
void parseNamespace();
void parseModuleImport();
void parseNew();
void parseAccessSpecifier();
bool parseEnum();
bool parseStructLike();
void parseConcept();
void parseRequires();
void parseRequiresExpression(unsigned int OriginalLevel);
void parseConstraintExpression(unsigned int OriginalLevel);
void parseJavaEnumBody();
// Parses a record (aka class) as a top level element. If ParseAsExpr is true,
// parses the record as a child block, i.e. if the class declaration is an
// expression.
void parseRecord(bool ParseAsExpr = false);
void parseObjCLightweightGenerics();
void parseObjCMethod();
void parseObjCProtocolList();
void parseObjCUntilAtEnd();
void parseObjCInterfaceOrImplementation();
bool parseObjCProtocol();
void parseJavaScriptEs6ImportExport();
void parseStatementMacro();
void parseCSharpAttribute();
// Parse a C# generic type constraint: `where T : IComparable<T>`.
// See:
void parseCSharpGenericTypeConstraint();
bool tryToParseLambda();
bool tryToParseLambdaIntroducer();
bool tryToParsePropertyAccessor();
void tryToParseJSFunction();
bool tryToParseSimpleAttribute();
// Used by addUnwrappedLine to denote whether to keep or remove a level
// when resetting the line state.
enum class LineLevel { Remove, Keep };
void addUnwrappedLine(LineLevel AdjustLevel = LineLevel::Remove);
bool eof() const;
// LevelDifference is the difference of levels after and before the current
// token. For example:
// - if the token is '{' and opens a block, LevelDifference is 1.
// - if the token is '}' and closes a block, LevelDifference is -1.
void nextToken(int LevelDifference = 0);
void readToken(int LevelDifference = 0);
// Decides which comment tokens should be added to the current line and which
// should be added as comments before the next token.
// Comments specifies the sequence of comment tokens to analyze. They get
// either pushed to the current line or added to the comments before the next
// token.
// NextTok specifies the next token. A null pointer NextTok is supported, and
// signifies either the absence of a next token, or that the next token
// shouldn't be taken into accunt for the analysis.
void distributeComments(const SmallVectorImpl<FormatToken *> &Comments,
const FormatToken *NextTok);
// Adds the comment preceding the next token to unwrapped lines.
void flushComments(bool NewlineBeforeNext);
void pushToken(FormatToken *Tok);
void calculateBraceTypes(bool ExpectClassBody = false);
// Marks a conditional compilation edge (for example, an '#if', '#ifdef',
// '#else' or merge conflict marker). If 'Unreachable' is true, assumes
// this branch either cannot be taken (for example '#if false'), or should
// not be taken in this round.
void conditionalCompilationCondition(bool Unreachable);
void conditionalCompilationStart(bool Unreachable);
void conditionalCompilationAlternative();
void conditionalCompilationEnd();
bool isOnNewLine(const FormatToken &FormatTok);
// Compute hash of the current preprocessor branch.
// This is used to identify the different branches, and thus track if block
// open and close in the same branch.
size_t computePPHash() const;
// FIXME: We are constantly running into bugs where Line.Level is incorrectly
// subtracted from beyond 0. Introduce a method to subtract from Line.Level
// and use that everywhere in the Parser.
std::unique_ptr<UnwrappedLine> Line;
// Comments are sorted into unwrapped lines by whether they are in the same
// line as the previous token, or not. If not, they belong to the next token.
// Since the next token might already be in a new unwrapped line, we need to
// store the comments belonging to that token.
SmallVector<FormatToken *, 1> CommentsBeforeNextToken;
FormatToken *FormatTok;
bool MustBreakBeforeNextToken;
// The parsed lines. Only added to through \c CurrentLines.
SmallVector<UnwrappedLine, 8> Lines;
// Preprocessor directives are parsed out-of-order from other unwrapped lines.
// Thus, we need to keep a list of preprocessor directives to be reported
// after an unwrapped line that has been started was finished.
SmallVector<UnwrappedLine, 4> PreprocessorDirectives;
// New unwrapped lines are added via CurrentLines.
// Usually points to \c &Lines. While parsing a preprocessor directive when
// there is an unfinished previous unwrapped line, will point to
// \c &PreprocessorDirectives.
SmallVectorImpl<UnwrappedLine> *CurrentLines;
// We store for each line whether it must be a declaration depending on
// whether we are in a compound statement or not.
std::vector<bool> DeclarationScopeStack;
const FormatStyle &Style;
const AdditionalKeywords &Keywords;
llvm::Regex CommentPragmasRegex;
FormatTokenSource *Tokens;
UnwrappedLineConsumer &Callback;
// FIXME: This is a temporary measure until we have reworked the ownership
// of the format tokens. The goal is to have the actual tokens created and
// owned outside of and handed into the UnwrappedLineParser.
ArrayRef<FormatToken *> AllTokens;
// Represents preprocessor branch type, so we can find matching
// #if/#else/#endif directives.
enum PPBranchKind {
PP_Conditional, // Any #if, #ifdef, #ifndef, #elif, block outside #if 0
PP_Unreachable // #if 0 or a conditional preprocessor block inside #if 0
struct PPBranch {
PPBranch(PPBranchKind Kind, size_t Line) : Kind(Kind), Line(Line) {}
PPBranchKind Kind;
size_t Line;
// Keeps a stack of currently active preprocessor branching directives.
SmallVector<PPBranch, 16> PPStack;
// The \c UnwrappedLineParser re-parses the code for each combination
// of preprocessor branches that can be taken.
// To that end, we take the same branch (#if, #else, or one of the #elif
// branches) for each nesting level of preprocessor branches.
// \c PPBranchLevel stores the current nesting level of preprocessor
// branches during one pass over the code.
int PPBranchLevel;
// Contains the current branch (#if, #else or one of the #elif branches)
// for each nesting level.
SmallVector<int, 8> PPLevelBranchIndex;
// Contains the maximum number of branches at each nesting level.
SmallVector<int, 8> PPLevelBranchCount;
// Contains the number of branches per nesting level we are currently
// in while parsing a preprocessor branch sequence.
// This is used to update PPLevelBranchCount at the end of a branch
// sequence.
std::stack<int> PPChainBranchIndex;
// Include guard search state. Used to fixup preprocessor indent levels
// so that include guards do not participate in indentation.
enum IncludeGuardState {
IG_Inited, // Search started, looking for #ifndef.
IG_IfNdefed, // #ifndef found, IncludeGuardToken points to condition.
IG_Defined, // Matching #define found, checking other requirements.
IG_Found, // All requirements met, need to fix indents.
IG_Rejected, // Search failed or never started.
// Current state of include guard search.
IncludeGuardState IncludeGuard;
// Points to the #ifndef condition for a potential include guard. Null unless
// IncludeGuardState == IG_IfNdefed.
FormatToken *IncludeGuardToken;
// Contains the first start column where the source begins. This is zero for
// normal source code and may be nonzero when formatting a code fragment that
// does not start at the beginning of the file.
unsigned FirstStartColumn;
friend class ScopedLineState;
friend class CompoundStatementIndenter;
struct UnwrappedLineNode {
UnwrappedLineNode() : Tok(nullptr) {}
UnwrappedLineNode(FormatToken *Tok) : Tok(Tok) {}
FormatToken *Tok;
SmallVector<UnwrappedLine, 0> Children;
inline UnwrappedLine::UnwrappedLine()
: Level(0), InPPDirective(false), MustBeDeclaration(false),
MatchingOpeningBlockLineIndex(kInvalidIndex) {}
} // end namespace format
} // end namespace clang