//===--- Token.h - Token interface ------------------------------*- C++ -*-===//
 
//
 
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 
// See https://llvm.org/LICENSE.txt for license information.
 
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
//
 
//===----------------------------------------------------------------------===//
 
//
 
//  This file defines the Token interface.
 
//
 
//===----------------------------------------------------------------------===//
 
 
 
#ifndef LLVM_CLANG_LEX_TOKEN_H
 
#define LLVM_CLANG_LEX_TOKEN_H
 
 
 
#include "clang/Basic/SourceLocation.h"
 
#include "clang/Basic/TokenKinds.h"
 
#include "llvm/ADT/ArrayRef.h"
 
#include "llvm/ADT/StringRef.h"
 
#include <cassert>
 
 
 
namespace clang {
 
 
 
class IdentifierInfo;
 
 
 
/// Token - This structure provides full information about a lexed token.
 
/// It is not intended to be space efficient, it is intended to return as much
 
/// information as possible about each returned token.  This is expected to be
 
/// compressed into a smaller form if memory footprint is important.
 
///
 
/// The parser can create a special "annotation token" representing a stream of
 
/// tokens that were parsed and semantically resolved, e.g.: "foo::MyClass<int>"
 
/// can be represented by a single typename annotation token that carries
 
/// information about the SourceRange of the tokens and the type object.
 
class Token {
 
  /// The location of the token. This is actually a SourceLocation.
 
  SourceLocation::UIntTy Loc;
 
 
 
  // Conceptually these next two fields could be in a union.  However, this
 
  // causes gcc 4.2 to pessimize LexTokenInternal, a very performance critical
 
  // routine. Keeping as separate members with casts until a more beautiful fix
 
  // presents itself.
 
 
 
  /// UintData - This holds either the length of the token text, when
 
  /// a normal token, or the end of the SourceRange when an annotation
 
  /// token.
 
  SourceLocation::UIntTy UintData;
 
 
 
  /// PtrData - This is a union of four different pointer types, which depends
 
  /// on what type of token this is:
 
  ///  Identifiers, keywords, etc:
 
  ///    This is an IdentifierInfo*, which contains the uniqued identifier
 
  ///    spelling.
 
  ///  Literals:  isLiteral() returns true.
 
  ///    This is a pointer to the start of the token in a text buffer, which
 
  ///    may be dirty (have trigraphs / escaped newlines).
 
  ///  Annotations (resolved type names, C++ scopes, etc): isAnnotation().
 
  ///    This is a pointer to sema-specific data for the annotation token.
 
  ///  Eof:
 
  //     This is a pointer to a Decl.
 
  ///  Other:
 
  ///    This is null.
 
  void *PtrData;
 
 
 
  /// Kind - The actual flavor of token this is.
 
  tok::TokenKind Kind;
 
 
 
  /// Flags - Bits we track about this token, members of the TokenFlags enum.
 
  unsigned short Flags;
 
 
 
public:
 
  // Various flags set per token:
 
  enum TokenFlags {
 
    StartOfLine = 0x01,   // At start of line or only after whitespace
 
                          // (considering the line after macro expansion).
 
    LeadingSpace = 0x02,  // Whitespace exists before this token (considering
 
                          // whitespace after macro expansion).
 
    DisableExpand = 0x04, // This identifier may never be macro expanded.
 
    NeedsCleaning = 0x08, // Contained an escaped newline or trigraph.
 
    LeadingEmptyMacro = 0x10, // Empty macro exists before this token.
 
    HasUDSuffix = 0x20,  // This string or character literal has a ud-suffix.
 
    HasUCN = 0x40,       // This identifier contains a UCN.
 
    IgnoredComma = 0x80, // This comma is not a macro argument separator (MS).
 
    StringifiedInMacro = 0x100, // This string or character literal is formed by
 
                                // macro stringizing or charizing operator.
 
    CommaAfterElided = 0x200, // The comma following this token was elided (MS).
 
    IsEditorPlaceholder = 0x400, // This identifier is a placeholder.
 
    IsReinjected = 0x800, // A phase 4 token that was produced before and
 
                          // re-added, e.g. via EnterTokenStream. Annotation
 
                          // tokens are *not* reinjected.
 
  };
 
 
 
  tok::TokenKind getKind() const { return Kind; }
 
  void setKind(tok::TokenKind K) { Kind = K; }
 
 
 
  /// is/isNot - Predicates to check if this token is a specific kind, as in
 
  /// "if (Tok.is(tok::l_brace)) {...}".
 
  bool is(tok::TokenKind K) const { return Kind == K; }
 
  bool isNot(tok::TokenKind K) const { return Kind != K; }
 
  bool isOneOf(tok::TokenKind K1, tok::TokenKind K2) const {
 
    return is(K1) || is(K2);
 
  }
 
  template <typename... Ts> bool isOneOf(tok::TokenKind K1, Ts... Ks) const {
 
    return is(K1) || isOneOf(Ks...);
 
  }
 
 
 
  /// Return true if this is a raw identifier (when lexing
 
  /// in raw mode) or a non-keyword identifier (when lexing in non-raw mode).
 
  bool isAnyIdentifier() const {
 
    return tok::isAnyIdentifier(getKind());
 
  }
 
 
 
  /// Return true if this is a "literal", like a numeric
 
  /// constant, string, etc.
 
  bool isLiteral() const {
 
    return tok::isLiteral(getKind());
 
  }
 
 
 
  /// Return true if this is any of tok::annot_* kind tokens.
 
  bool isAnnotation() const {
 
    return tok::isAnnotation(getKind());
 
  }
 
 
 
  /// Return a source location identifier for the specified
 
  /// offset in the current file.
 
  SourceLocation getLocation() const {
 
    return SourceLocation::getFromRawEncoding(Loc);
 
  }
 
  unsigned getLength() const {
 
    assert(!isAnnotation() && "Annotation tokens have no length field");
 
    return UintData;
 
  }
 
 
 
  void setLocation(SourceLocation L) { Loc = L.getRawEncoding(); }
 
  void setLength(unsigned Len) {
 
    assert(!isAnnotation() && "Annotation tokens have no length field");
 
    UintData = Len;
 
  }
 
 
 
  SourceLocation getAnnotationEndLoc() const {
 
    assert(isAnnotation() && "Used AnnotEndLocID on non-annotation token");
 
    return SourceLocation::getFromRawEncoding(UintData ? UintData : Loc);
 
  }
 
  void setAnnotationEndLoc(SourceLocation L) {
 
    assert(isAnnotation() && "Used AnnotEndLocID on non-annotation token");
 
    UintData = L.getRawEncoding();
 
  }
 
 
 
  SourceLocation getLastLoc() const {
 
    return isAnnotation() ? getAnnotationEndLoc() : getLocation();
 
  }
 
 
 
  SourceLocation getEndLoc() const {
 
    return isAnnotation() ? getAnnotationEndLoc()
 
                          : getLocation().getLocWithOffset(getLength());
 
  }
 
 
 
  /// SourceRange of the group of tokens that this annotation token
 
  /// represents.
 
  SourceRange getAnnotationRange() const {
 
    return SourceRange(getLocation(), getAnnotationEndLoc());
 
  }
 
  void setAnnotationRange(SourceRange R) {
 
    setLocation(R.getBegin());
 
    setAnnotationEndLoc(R.getEnd());
 
  }
 
 
 
  const char *getName() const { return tok::getTokenName(Kind); }
 
 
 
  /// Reset all flags to cleared.
 
  void startToken() {
 
    Kind = tok::unknown;
 
    Flags = 0;
 
    PtrData = nullptr;
 
    UintData = 0;
 
    Loc = SourceLocation().getRawEncoding();
 
  }
 
 
 
  bool hasPtrData() const { return PtrData != nullptr; }
 
 
 
  IdentifierInfo *getIdentifierInfo() const {
 
    assert(isNot(tok::raw_identifier) &&
 
           "getIdentifierInfo() on a tok::raw_identifier token!");
 
    assert(!isAnnotation() &&
 
           "getIdentifierInfo() on an annotation token!");
 
    if (isLiteral()) return nullptr;
 
    if (is(tok::eof)) return nullptr;
 
    return (IdentifierInfo*) PtrData;
 
  }
 
  void setIdentifierInfo(IdentifierInfo *II) {
 
    PtrData = (void*) II;
 
  }
 
 
 
  const void *getEofData() const {
 
    assert(is(tok::eof));
 
    return reinterpret_cast<const void *>(PtrData);
 
  }
 
  void setEofData(const void *D) {
 
    assert(is(tok::eof));
 
    assert(!PtrData);
 
    PtrData = const_cast<void *>(D);
 
  }
 
 
 
  /// getRawIdentifier - For a raw identifier token (i.e., an identifier
 
  /// lexed in raw mode), returns a reference to the text substring in the
 
  /// buffer if known.
 
  StringRef getRawIdentifier() const {
 
    assert(is(tok::raw_identifier));
 
    return StringRef(reinterpret_cast<const char *>(PtrData), getLength());
 
  }
 
  void setRawIdentifierData(const char *Ptr) {
 
    assert(is(tok::raw_identifier));
 
    PtrData = const_cast<char*>(Ptr);
 
  }
 
 
 
  /// getLiteralData - For a literal token (numeric constant, string, etc), this
 
  /// returns a pointer to the start of it in the text buffer if known, null
 
  /// otherwise.
 
  const char *getLiteralData() const {
 
    assert(isLiteral() && "Cannot get literal data of non-literal");
 
    return reinterpret_cast<const char*>(PtrData);
 
  }
 
  void setLiteralData(const char *Ptr) {
 
    assert(isLiteral() && "Cannot set literal data of non-literal");
 
    PtrData = const_cast<char*>(Ptr);
 
  }
 
 
 
  void *getAnnotationValue() const {
 
    assert(isAnnotation() && "Used AnnotVal on non-annotation token");
 
    return PtrData;
 
  }
 
  void setAnnotationValue(void *val) {
 
    assert(isAnnotation() && "Used AnnotVal on non-annotation token");
 
    PtrData = val;
 
  }
 
 
 
  /// Set the specified flag.
 
  void setFlag(TokenFlags Flag) {
 
    Flags |= Flag;
 
  }
 
 
 
  /// Get the specified flag.
 
  bool getFlag(TokenFlags Flag) const {
 
    return (Flags & Flag) != 0;
 
  }
 
 
 
  /// Unset the specified flag.
 
  void clearFlag(TokenFlags Flag) {
 
    Flags &= ~Flag;
 
  }
 
 
 
  /// Return the internal represtation of the flags.
 
  ///
 
  /// This is only intended for low-level operations such as writing tokens to
 
  /// disk.
 
  unsigned getFlags() const {
 
    return Flags;
 
  }
 
 
 
  /// Set a flag to either true or false.
 
  void setFlagValue(TokenFlags Flag, bool Val) {
 
    if (Val)
 
      setFlag(Flag);
 
    else
 
      clearFlag(Flag);
 
  }
 
 
 
  /// isAtStartOfLine - Return true if this token is at the start of a line.
 
  ///
 
  bool isAtStartOfLine() const { return getFlag(StartOfLine); }
 
 
 
  /// Return true if this token has whitespace before it.
 
  ///
 
  bool hasLeadingSpace() const { return getFlag(LeadingSpace); }
 
 
 
  /// Return true if this identifier token should never
 
  /// be expanded in the future, due to C99 6.10.3.4p2.
 
  bool isExpandDisabled() const { return getFlag(DisableExpand); }
 
 
 
  /// Return true if we have an ObjC keyword identifier.
 
  bool isObjCAtKeyword(tok::ObjCKeywordKind objcKey) const;
 
 
 
  /// Return the ObjC keyword kind.
 
  tok::ObjCKeywordKind getObjCKeywordID() const;
 
 
 
  /// Return true if this token has trigraphs or escaped newlines in it.
 
  bool needsCleaning() const { return getFlag(NeedsCleaning); }
 
 
 
  /// Return true if this token has an empty macro before it.
 
  ///
 
  bool hasLeadingEmptyMacro() const { return getFlag(LeadingEmptyMacro); }
 
 
 
  /// Return true if this token is a string or character literal which
 
  /// has a ud-suffix.
 
  bool hasUDSuffix() const { return getFlag(HasUDSuffix); }
 
 
 
  /// Returns true if this token contains a universal character name.
 
  bool hasUCN() const { return getFlag(HasUCN); }
 
 
 
  /// Returns true if this token is formed by macro by stringizing or charizing
 
  /// operator.
 
  bool stringifiedInMacro() const { return getFlag(StringifiedInMacro); }
 
 
 
  /// Returns true if the comma after this token was elided.
 
  bool commaAfterElided() const { return getFlag(CommaAfterElided); }
 
 
 
  /// Returns true if this token is an editor placeholder.
 
  ///
 
  /// Editor placeholders are produced by the code-completion engine and are
 
  /// represented as characters between '<#' and '#>' in the source code. The
 
  /// lexer uses identifier tokens to represent placeholders.
 
  bool isEditorPlaceholder() const { return getFlag(IsEditorPlaceholder); }
 
};
 
 
 
/// Information about the conditional stack (\#if directives)
 
/// currently active.
 
struct PPConditionalInfo {
 
  /// Location where the conditional started.
 
  SourceLocation IfLoc;
 
 
 
  /// True if this was contained in a skipping directive, e.g.,
 
  /// in a "\#if 0" block.
 
  bool WasSkipping;
 
 
 
  /// True if we have emitted tokens already, and now we're in
 
  /// an \#else block or something.  Only useful in Skipping blocks.
 
  bool FoundNonSkip;
 
 
 
  /// True if we've seen a \#else in this block.  If so,
 
  /// \#elif/\#else directives are not allowed.
 
  bool FoundElse;
 
};
 
 
 
// Extra information needed for annonation tokens.
 
struct PragmaLoopHintInfo {
 
  Token PragmaName;
 
  Token Option;
 
  ArrayRef<Token> Toks;
 
};
 
} // end namespace clang
 
 
 
#endif // LLVM_CLANG_LEX_TOKEN_H