lib/Parse/RAIIObjectsForParser.h - platform/external/clang - Git at Google

 //===--- RAIIObjectsForParser.h - RAII helpers for the parser ---*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file defines and implements the some simple RAII objects that are used
 // by the parser to manage bits in recursion.
 //
 //===----------------------------------------------------------------------===//

 #ifndef LLVM_CLANG_PARSE_RAII_OBJECTS_FOR_PARSER_H
 #define LLVM_CLANG_PARSE_RAII_OBJECTS_FOR_PARSER_H

 #include "clang/Parse/ParseDiagnostic.h"
 #include "clang/Parse/Parser.h"
 #include "clang/Sema/DelayedDiagnostic.h"
 #include "clang/Sema/Sema.h"

 namespace clang {
   // TODO: move ParsingClassDefinition here.
   // TODO: move TentativeParsingAction here.

   /// \brief A RAII object used to temporarily suppress access-like
   /// checking.  Access-like checks are those associated with
   /// controlling the use of a declaration, like C++ access control
   /// errors and deprecation warnings.  They are contextually
   /// dependent, in that they can only be resolved with full
   /// information about what's being declared.  They are also
   /// suppressed in certain contexts, like the template arguments of
   /// an explicit instantiation.  However, those suppression contexts
   /// cannot necessarily be fully determined in advance;  for
   /// example, something starting like this:
   ///   template <> class std::vector<A::PrivateType>
   /// might be the entirety of an explicit instantiation:
   ///   template <> class std::vector<A::PrivateType>;
   /// or just an elaborated type specifier:
   ///   template <> class std::vector<A::PrivateType> make_vector<>();
   /// Therefore this class collects all the diagnostics and permits
   /// them to be re-delayed in a new context.
   class SuppressAccessChecks {
     Sema &S;
     sema::DelayedDiagnosticPool DiagnosticPool;
     Sema::ParsingDeclState State;
     bool Active;

   public:
     /// Begin suppressing access-like checks
     SuppressAccessChecks(Parser &P, bool activate = true)
         : S(P.getActions()), DiagnosticPool(NULL) {
       if (activate) {
         State = S.PushParsingDeclaration(DiagnosticPool);
         Active = true;
       } else {
         Active = false;
       }
     }

     void done() {
       assert(Active && "trying to end an inactive suppression");
       S.PopParsingDeclaration(State, NULL);
       Active = false;
     }

     void redelay() {
       assert(!Active && "redelaying without having ended first");
       if (!DiagnosticPool.pool_empty())
         S.redelayDiagnostics(DiagnosticPool);
       assert(DiagnosticPool.pool_empty());
     }

     ~SuppressAccessChecks() {
       if (Active) done();
     }
   };

   /// \brief RAII object used to inform the actions that we're
   /// currently parsing a declaration.  This is active when parsing a
   /// variable's initializer, but not when parsing the body of a
   /// class or function definition.
   class ParsingDeclRAIIObject {
     Sema &Actions;
     sema::DelayedDiagnosticPool DiagnosticPool;
     Sema::ParsingDeclState State;
     bool Popped;

     ParsingDeclRAIIObject(const ParsingDeclRAIIObject &) LLVM_DELETED_FUNCTION;
     void operator=(const ParsingDeclRAIIObject &) LLVM_DELETED_FUNCTION;

   public:
     enum NoParent_t { NoParent };
     ParsingDeclRAIIObject(Parser &P, NoParent_t _)
         : Actions(P.getActions()), DiagnosticPool(NULL) {
       push();
     }

     /// Creates a RAII object whose pool is optionally parented by another.
     ParsingDeclRAIIObject(Parser &P,
                           const sema::DelayedDiagnosticPool *parentPool)
         : Actions(P.getActions()), DiagnosticPool(parentPool) {
       push();
     }

     /// Creates a RAII object and, optionally, initialize its
     /// diagnostics pool by stealing the diagnostics from another
     /// RAII object (which is assumed to be the current top pool).
     ParsingDeclRAIIObject(Parser &P, ParsingDeclRAIIObject *other)
         : Actions(P.getActions()),
           DiagnosticPool(other ? other->DiagnosticPool.getParent() : NULL) {
       if (other) {
         DiagnosticPool.steal(other->DiagnosticPool);
         other->abort();
       }
       push();
     }

     ~ParsingDeclRAIIObject() {
       abort();
     }

     sema::DelayedDiagnosticPool &getDelayedDiagnosticPool() {
       return DiagnosticPool;
     }
     const sema::DelayedDiagnosticPool &getDelayedDiagnosticPool() const {
       return DiagnosticPool;
     }

     /// Resets the RAII object for a new declaration.
     void reset() {
       abort();
       push();
     }

     /// Signals that the context was completed without an appropriate
     /// declaration being parsed.
     void abort() {
       pop(0);
     }

     void complete(Decl *D) {
       assert(!Popped && "ParsingDeclaration has already been popped!");
       pop(D);
     }

     /// Unregister this object from Sema, but remember all the
     /// diagnostics that were emitted into it.
     void abortAndRemember() {
       pop(0);
     }

   private:
     void push() {
       State = Actions.PushParsingDeclaration(DiagnosticPool);
       Popped = false;
     }

     void pop(Decl *D) {
       if (!Popped) {
         Actions.PopParsingDeclaration(State, D);
         Popped = true;
       }
     }
   };

   /// A class for parsing a DeclSpec.
   class ParsingDeclSpec : public DeclSpec {
     ParsingDeclRAIIObject ParsingRAII;

   public:
     ParsingDeclSpec(Parser &P)
       : DeclSpec(P.getAttrFactory()),
         ParsingRAII(P, ParsingDeclRAIIObject::NoParent) {}
     ParsingDeclSpec(Parser &P, ParsingDeclRAIIObject *RAII)
       : DeclSpec(P.getAttrFactory()),
         ParsingRAII(P, RAII) {}

     const sema::DelayedDiagnosticPool &getDelayedDiagnosticPool() const {
       return ParsingRAII.getDelayedDiagnosticPool();
     }

     void complete(Decl *D) {
       ParsingRAII.complete(D);
     }

     void abort() {
       ParsingRAII.abort();
     }
   };

   /// A class for parsing a declarator.
   class ParsingDeclarator : public Declarator {
     ParsingDeclRAIIObject ParsingRAII;

   public:
     ParsingDeclarator(Parser &P, const ParsingDeclSpec &DS, TheContext C)
       : Declarator(DS, C), ParsingRAII(P, &DS.getDelayedDiagnosticPool()) {
     }

     const ParsingDeclSpec &getDeclSpec() const {
       return static_cast<const ParsingDeclSpec&>(Declarator::getDeclSpec());
     }

     ParsingDeclSpec &getMutableDeclSpec() const {
       return const_cast<ParsingDeclSpec&>(getDeclSpec());
     }

     void clear() {
       Declarator::clear();
       ParsingRAII.reset();
     }

     void complete(Decl *D) {
       ParsingRAII.complete(D);
     }
   };

   /// A class for parsing a field declarator.
   class ParsingFieldDeclarator : public FieldDeclarator {
     ParsingDeclRAIIObject ParsingRAII;

   public:
     ParsingFieldDeclarator(Parser &P, const ParsingDeclSpec &DS)
       : FieldDeclarator(DS), ParsingRAII(P, &DS.getDelayedDiagnosticPool()) {
     }

     const ParsingDeclSpec &getDeclSpec() const {
       return static_cast<const ParsingDeclSpec&>(D.getDeclSpec());
     }

     ParsingDeclSpec &getMutableDeclSpec() const {
       return const_cast<ParsingDeclSpec&>(getDeclSpec());
     }

     void complete(Decl *D) {
       ParsingRAII.complete(D);
     }
   };

   /// ExtensionRAIIObject - This saves the state of extension warnings when
   /// constructed and disables them.  When destructed, it restores them back to
   /// the way they used to be.  This is used to handle __extension__ in the
   /// parser.
   class ExtensionRAIIObject {
     ExtensionRAIIObject(const ExtensionRAIIObject &) LLVM_DELETED_FUNCTION;
     void operator=(const ExtensionRAIIObject &) LLVM_DELETED_FUNCTION;

     DiagnosticsEngine &Diags;
   public:
     ExtensionRAIIObject(DiagnosticsEngine &diags) : Diags(diags) {
       Diags.IncrementAllExtensionsSilenced();
     }

     ~ExtensionRAIIObject() {
       Diags.DecrementAllExtensionsSilenced();
     }
   };

   /// ColonProtectionRAIIObject - This sets the Parser::ColonIsSacred bool and
   /// restores it when destroyed.  This says that "foo:" should not be
   /// considered a possible typo for "foo::" for error recovery purposes.
   class ColonProtectionRAIIObject {
     Parser &P;
     bool OldVal;
   public:
     ColonProtectionRAIIObject(Parser &p, bool Value = true)
       : P(p), OldVal(P.ColonIsSacred) {
       P.ColonIsSacred = Value;
     }

     /// restore - This can be used to restore the state early, before the dtor
     /// is run.
     void restore() {
       P.ColonIsSacred = OldVal;
     }

     ~ColonProtectionRAIIObject() {
       restore();
     }
   };

   /// \brief RAII object that makes '>' behave either as an operator
   /// or as the closing angle bracket for a template argument list.
   class GreaterThanIsOperatorScope {
     bool &GreaterThanIsOperator;
     bool OldGreaterThanIsOperator;
   public:
     GreaterThanIsOperatorScope(bool &GTIO, bool Val)
     : GreaterThanIsOperator(GTIO), OldGreaterThanIsOperator(GTIO) {
       GreaterThanIsOperator = Val;
     }

     ~GreaterThanIsOperatorScope() {
       GreaterThanIsOperator = OldGreaterThanIsOperator;
     }
   };

   class InMessageExpressionRAIIObject {
     bool &InMessageExpression;
     bool OldValue;

   public:
     InMessageExpressionRAIIObject(Parser &P, bool Value)
       : InMessageExpression(P.InMessageExpression),
         OldValue(P.InMessageExpression) {
       InMessageExpression = Value;
     }

     ~InMessageExpressionRAIIObject() {
       InMessageExpression = OldValue;
     }
   };

   /// \brief RAII object that makes sure paren/bracket/brace count is correct
   /// after declaration/statement parsing, even when there's a parsing error.
   class ParenBraceBracketBalancer {
     Parser &P;
     unsigned short ParenCount, BracketCount, BraceCount;
   public:
     ParenBraceBracketBalancer(Parser &p)
       : P(p), ParenCount(p.ParenCount), BracketCount(p.BracketCount),
         BraceCount(p.BraceCount) { }

     ~ParenBraceBracketBalancer() {
       P.ParenCount = ParenCount;
       P.BracketCount = BracketCount;
       P.BraceCount = BraceCount;
     }
   };

   class PoisonSEHIdentifiersRAIIObject {
     PoisonIdentifierRAIIObject Ident_AbnormalTermination;
     PoisonIdentifierRAIIObject Ident_GetExceptionCode;
     PoisonIdentifierRAIIObject Ident_GetExceptionInfo;
     PoisonIdentifierRAIIObject Ident__abnormal_termination;
     PoisonIdentifierRAIIObject Ident__exception_code;
     PoisonIdentifierRAIIObject Ident__exception_info;
     PoisonIdentifierRAIIObject Ident___abnormal_termination;
     PoisonIdentifierRAIIObject Ident___exception_code;
     PoisonIdentifierRAIIObject Ident___exception_info;
   public:
     PoisonSEHIdentifiersRAIIObject(Parser &Self, bool NewValue)
       : Ident_AbnormalTermination(Self.Ident_AbnormalTermination, NewValue),
         Ident_GetExceptionCode(Self.Ident_GetExceptionCode, NewValue),
         Ident_GetExceptionInfo(Self.Ident_GetExceptionInfo, NewValue),
         Ident__abnormal_termination(Self.Ident__abnormal_termination, NewValue),
         Ident__exception_code(Self.Ident__exception_code, NewValue),
         Ident__exception_info(Self.Ident__exception_info, NewValue),
         Ident___abnormal_termination(Self.Ident___abnormal_termination, NewValue),
         Ident___exception_code(Self.Ident___exception_code, NewValue),
         Ident___exception_info(Self.Ident___exception_info, NewValue) {
     }
   };

   /// \brief RAII class that helps handle the parsing of an open/close delimiter
   /// pair, such as braces { ... } or parentheses ( ... ).
   class BalancedDelimiterTracker : public GreaterThanIsOperatorScope {
     Parser& P;
     tok::TokenKind Kind, Close;
     SourceLocation (Parser::*Consumer)();
     SourceLocation LOpen, LClose;

     unsigned short &getDepth() {
       switch (Kind) {
         case tok::l_brace: return P.BraceCount;
         case tok::l_square: return P.BracketCount;
         case tok::l_paren: return P.ParenCount;
         default: llvm_unreachable("Wrong token kind");
       }
     }

     enum { MaxDepth = 256 };

     bool diagnoseOverflow();
     bool diagnoseMissingClose();

   public:
     BalancedDelimiterTracker(Parser& p, tok::TokenKind k)
       : GreaterThanIsOperatorScope(p.GreaterThanIsOperator, true),
         P(p), Kind(k)
     {
       switch (Kind) {
         default: llvm_unreachable("Unexpected balanced token");
         case tok::l_brace:
           Close = tok::r_brace;
           Consumer = &Parser::ConsumeBrace;
           break;
         case tok::l_paren:
           Close = tok::r_paren;
           Consumer = &Parser::ConsumeParen;
           break;

         case tok::l_square:
           Close = tok::r_square;
           Consumer = &Parser::ConsumeBracket;
           break;
       }
     }

     SourceLocation getOpenLocation() const { return LOpen; }
     SourceLocation getCloseLocation() const { return LClose; }
     SourceRange getRange() const { return SourceRange(LOpen, LClose); }

     bool consumeOpen() {
       if (!P.Tok.is(Kind))
         return true;

       if (getDepth() < P.getLangOpts().BracketDepth) {
         LOpen = (P.*Consumer)();
         return false;
       }

       return diagnoseOverflow();
     }

     bool expectAndConsume(unsigned DiagID,
                           const char *Msg = "",
                           tok::TokenKind SkipToTok = tok::unknown);
     bool consumeClose() {
       if (P.Tok.is(Close)) {
         LClose = (P.*Consumer)();
         return false;
       }

       return diagnoseMissingClose();
     }
     void skipToEnd();
   };

 } // end namespace clang

 #endif
	//===--- RAIIObjectsForParser.h - RAII helpers for the parser ---- C++ --===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This file defines and implements the some simple RAII objects that are used
	// by the parser to manage bits in recursion.
	//
	//===----------------------------------------------------------------------===//

	#ifndef LLVM_CLANG_PARSE_RAII_OBJECTS_FOR_PARSER_H
	#define LLVM_CLANG_PARSE_RAII_OBJECTS_FOR_PARSER_H

	#include "clang/Parse/ParseDiagnostic.h"
	#include "clang/Parse/Parser.h"
	#include "clang/Sema/DelayedDiagnostic.h"
	#include "clang/Sema/Sema.h"

	namespace clang {
	// TODO: move ParsingClassDefinition here.
	// TODO: move TentativeParsingAction here.

	/// \brief A RAII object used to temporarily suppress access-like
	/// checking. Access-like checks are those associated with
	/// controlling the use of a declaration, like C++ access control
	/// errors and deprecation warnings. They are contextually
	/// dependent, in that they can only be resolved with full
	/// information about what's being declared. They are also
	/// suppressed in certain contexts, like the template arguments of
	/// an explicit instantiation. However, those suppression contexts
	/// cannot necessarily be fully determined in advance; for
	/// example, something starting like this:
	/// template <> class std::vector<A::PrivateType>
	/// might be the entirety of an explicit instantiation:
	/// template <> class std::vector<A::PrivateType>;
	/// or just an elaborated type specifier:
	/// template <> class std::vector<A::PrivateType> make_vector<>();
	/// Therefore this class collects all the diagnostics and permits
	/// them to be re-delayed in a new context.
	class SuppressAccessChecks {
	Sema &S;
	sema::DelayedDiagnosticPool DiagnosticPool;
	Sema::ParsingDeclState State;
	bool Active;

	public:
	/// Begin suppressing access-like checks
	SuppressAccessChecks(Parser &P, bool activate = true)
	: S(P.getActions()), DiagnosticPool(NULL) {
	if (activate) {
	State = S.PushParsingDeclaration(DiagnosticPool);
	Active = true;
	} else {
	Active = false;
	}
	}

	void done() {
	assert(Active && "trying to end an inactive suppression");
	S.PopParsingDeclaration(State, NULL);
	Active = false;
	}

	void redelay() {
	assert(!Active && "redelaying without having ended first");
	if (!DiagnosticPool.pool_empty())
	S.redelayDiagnostics(DiagnosticPool);
	assert(DiagnosticPool.pool_empty());
	}

	~SuppressAccessChecks() {
	if (Active) done();
	}
	};

	/// \brief RAII object used to inform the actions that we're
	/// currently parsing a declaration. This is active when parsing a
	/// variable's initializer, but not when parsing the body of a
	/// class or function definition.
	class ParsingDeclRAIIObject {
	Sema &Actions;
	sema::DelayedDiagnosticPool DiagnosticPool;
	Sema::ParsingDeclState State;
	bool Popped;

	ParsingDeclRAIIObject(const ParsingDeclRAIIObject &) LLVM_DELETED_FUNCTION;
	void operator=(const ParsingDeclRAIIObject &) LLVM_DELETED_FUNCTION;

	public:
	enum NoParent_t { NoParent };
	ParsingDeclRAIIObject(Parser &P, NoParent_t _)
	: Actions(P.getActions()), DiagnosticPool(NULL) {
	push();
	}

	/// Creates a RAII object whose pool is optionally parented by another.
	ParsingDeclRAIIObject(Parser &P,
	const sema::DelayedDiagnosticPool *parentPool)
	: Actions(P.getActions()), DiagnosticPool(parentPool) {
	push();
	}

	/// Creates a RAII object and, optionally, initialize its
	/// diagnostics pool by stealing the diagnostics from another
	/// RAII object (which is assumed to be the current top pool).
	ParsingDeclRAIIObject(Parser &P, ParsingDeclRAIIObject *other)
	: Actions(P.getActions()),
	DiagnosticPool(other ? other->DiagnosticPool.getParent() : NULL) {
	if (other) {
	DiagnosticPool.steal(other->DiagnosticPool);
	other->abort();
	}
	push();
	}

	~ParsingDeclRAIIObject() {
	abort();
	}

	sema::DelayedDiagnosticPool &getDelayedDiagnosticPool() {
	return DiagnosticPool;
	}
	const sema::DelayedDiagnosticPool &getDelayedDiagnosticPool() const {
	return DiagnosticPool;
	}

	/// Resets the RAII object for a new declaration.
	void reset() {
	abort();
	push();
	}

	/// Signals that the context was completed without an appropriate
	/// declaration being parsed.
	void abort() {
	pop(0);
	}

	void complete(Decl *D) {
	assert(!Popped && "ParsingDeclaration has already been popped!");
	pop(D);
	}

	/// Unregister this object from Sema, but remember all the
	/// diagnostics that were emitted into it.
	void abortAndRemember() {
	pop(0);
	}

	private:
	void push() {
	State = Actions.PushParsingDeclaration(DiagnosticPool);
	Popped = false;
	}

	void pop(Decl *D) {
	if (!Popped) {
	Actions.PopParsingDeclaration(State, D);
	Popped = true;
	}
	}
	};

	/// A class for parsing a DeclSpec.
	class ParsingDeclSpec : public DeclSpec {
	ParsingDeclRAIIObject ParsingRAII;

	public:
	ParsingDeclSpec(Parser &P)
	: DeclSpec(P.getAttrFactory()),
	ParsingRAII(P, ParsingDeclRAIIObject::NoParent) {}
	ParsingDeclSpec(Parser &P, ParsingDeclRAIIObject *RAII)
	: DeclSpec(P.getAttrFactory()),
	ParsingRAII(P, RAII) {}

	const sema::DelayedDiagnosticPool &getDelayedDiagnosticPool() const {
	return ParsingRAII.getDelayedDiagnosticPool();
	}

	void complete(Decl *D) {
	ParsingRAII.complete(D);
	}

	void abort() {
	ParsingRAII.abort();
	}
	};

	/// A class for parsing a declarator.
	class ParsingDeclarator : public Declarator {
	ParsingDeclRAIIObject ParsingRAII;

	public:
	ParsingDeclarator(Parser &P, const ParsingDeclSpec &DS, TheContext C)
	: Declarator(DS, C), ParsingRAII(P, &DS.getDelayedDiagnosticPool()) {
	}

	const ParsingDeclSpec &getDeclSpec() const {
	return static_cast<const ParsingDeclSpec&>(Declarator::getDeclSpec());
	}

	ParsingDeclSpec &getMutableDeclSpec() const {
	return const_cast<ParsingDeclSpec&>(getDeclSpec());
	}

	void clear() {
	Declarator::clear();
	ParsingRAII.reset();
	}

	void complete(Decl *D) {
	ParsingRAII.complete(D);
	}
	};

	/// A class for parsing a field declarator.
	class ParsingFieldDeclarator : public FieldDeclarator {
	ParsingDeclRAIIObject ParsingRAII;

	public:
	ParsingFieldDeclarator(Parser &P, const ParsingDeclSpec &DS)
	: FieldDeclarator(DS), ParsingRAII(P, &DS.getDelayedDiagnosticPool()) {
	}

	const ParsingDeclSpec &getDeclSpec() const {
	return static_cast<const ParsingDeclSpec&>(D.getDeclSpec());
	}

	ParsingDeclSpec &getMutableDeclSpec() const {
	return const_cast<ParsingDeclSpec&>(getDeclSpec());
	}

	void complete(Decl *D) {
	ParsingRAII.complete(D);
	}
	};

	/// ExtensionRAIIObject - This saves the state of extension warnings when
	/// constructed and disables them. When destructed, it restores them back to
	/// the way they used to be. This is used to handle __extension__ in the
	/// parser.
	class ExtensionRAIIObject {
	ExtensionRAIIObject(const ExtensionRAIIObject &) LLVM_DELETED_FUNCTION;
	void operator=(const ExtensionRAIIObject &) LLVM_DELETED_FUNCTION;

	DiagnosticsEngine &Diags;
	public:
	ExtensionRAIIObject(DiagnosticsEngine &diags) : Diags(diags) {
	Diags.IncrementAllExtensionsSilenced();
	}

	~ExtensionRAIIObject() {
	Diags.DecrementAllExtensionsSilenced();
	}
	};

	/// ColonProtectionRAIIObject - This sets the Parser::ColonIsSacred bool and
	/// restores it when destroyed. This says that "foo:" should not be
	/// considered a possible typo for "foo::" for error recovery purposes.
	class ColonProtectionRAIIObject {
	Parser &P;
	bool OldVal;
	public:
	ColonProtectionRAIIObject(Parser &p, bool Value = true)
	: P(p), OldVal(P.ColonIsSacred) {
	P.ColonIsSacred = Value;
	}

	/// restore - This can be used to restore the state early, before the dtor
	/// is run.
	void restore() {
	P.ColonIsSacred = OldVal;
	}

	~ColonProtectionRAIIObject() {
	restore();
	}
	};

	/// \brief RAII object that makes '>' behave either as an operator
	/// or as the closing angle bracket for a template argument list.
	class GreaterThanIsOperatorScope {
	bool &GreaterThanIsOperator;
	bool OldGreaterThanIsOperator;
	public:
	GreaterThanIsOperatorScope(bool &GTIO, bool Val)
	: GreaterThanIsOperator(GTIO), OldGreaterThanIsOperator(GTIO) {
	GreaterThanIsOperator = Val;
	}

	~GreaterThanIsOperatorScope() {
	GreaterThanIsOperator = OldGreaterThanIsOperator;
	}
	};

	class InMessageExpressionRAIIObject {
	bool &InMessageExpression;
	bool OldValue;

	public:
	InMessageExpressionRAIIObject(Parser &P, bool Value)
	: InMessageExpression(P.InMessageExpression),
	OldValue(P.InMessageExpression) {
	InMessageExpression = Value;
	}

	~InMessageExpressionRAIIObject() {
	InMessageExpression = OldValue;
	}
	};

	/// \brief RAII object that makes sure paren/bracket/brace count is correct
	/// after declaration/statement parsing, even when there's a parsing error.
	class ParenBraceBracketBalancer {
	Parser &P;
	unsigned short ParenCount, BracketCount, BraceCount;
	public:
	ParenBraceBracketBalancer(Parser &p)
	: P(p), ParenCount(p.ParenCount), BracketCount(p.BracketCount),
	BraceCount(p.BraceCount) { }

	~ParenBraceBracketBalancer() {
	P.ParenCount = ParenCount;
	P.BracketCount = BracketCount;
	P.BraceCount = BraceCount;
	}
	};

	class PoisonSEHIdentifiersRAIIObject {
	PoisonIdentifierRAIIObject Ident_AbnormalTermination;
	PoisonIdentifierRAIIObject Ident_GetExceptionCode;
	PoisonIdentifierRAIIObject Ident_GetExceptionInfo;
	PoisonIdentifierRAIIObject Ident__abnormal_termination;
	PoisonIdentifierRAIIObject Ident__exception_code;
	PoisonIdentifierRAIIObject Ident__exception_info;
	PoisonIdentifierRAIIObject Ident___abnormal_termination;
	PoisonIdentifierRAIIObject Ident___exception_code;
	PoisonIdentifierRAIIObject Ident___exception_info;
	public:
	PoisonSEHIdentifiersRAIIObject(Parser &Self, bool NewValue)
	: Ident_AbnormalTermination(Self.Ident_AbnormalTermination, NewValue),
	Ident_GetExceptionCode(Self.Ident_GetExceptionCode, NewValue),
	Ident_GetExceptionInfo(Self.Ident_GetExceptionInfo, NewValue),
	Ident__abnormal_termination(Self.Ident__abnormal_termination, NewValue),
	Ident__exception_code(Self.Ident__exception_code, NewValue),
	Ident__exception_info(Self.Ident__exception_info, NewValue),
	Ident___abnormal_termination(Self.Ident___abnormal_termination, NewValue),
	Ident___exception_code(Self.Ident___exception_code, NewValue),
	Ident___exception_info(Self.Ident___exception_info, NewValue) {
	}
	};

	/// \brief RAII class that helps handle the parsing of an open/close delimiter
	/// pair, such as braces { ... } or parentheses ( ... ).
	class BalancedDelimiterTracker : public GreaterThanIsOperatorScope {
	Parser& P;
	tok::TokenKind Kind, Close;
	SourceLocation (Parser::*Consumer)();
	SourceLocation LOpen, LClose;

	unsigned short &getDepth() {
	switch (Kind) {
	case tok::l_brace: return P.BraceCount;
	case tok::l_square: return P.BracketCount;
	case tok::l_paren: return P.ParenCount;
	default: llvm_unreachable("Wrong token kind");
	}
	}

	enum { MaxDepth = 256 };

	bool diagnoseOverflow();
	bool diagnoseMissingClose();

	public:
	BalancedDelimiterTracker(Parser& p, tok::TokenKind k)
	: GreaterThanIsOperatorScope(p.GreaterThanIsOperator, true),
	P(p), Kind(k)
	{
	switch (Kind) {
	default: llvm_unreachable("Unexpected balanced token");
	case tok::l_brace:
	Close = tok::r_brace;
	Consumer = &Parser::ConsumeBrace;
	break;
	case tok::l_paren:
	Close = tok::r_paren;
	Consumer = &Parser::ConsumeParen;
	break;

	case tok::l_square:
	Close = tok::r_square;
	Consumer = &Parser::ConsumeBracket;
	break;
	}
	}

	SourceLocation getOpenLocation() const { return LOpen; }
	SourceLocation getCloseLocation() const { return LClose; }
	SourceRange getRange() const { return SourceRange(LOpen, LClose); }

	bool consumeOpen() {
	if (!P.Tok.is(Kind))
	return true;

	if (getDepth() < P.getLangOpts().BracketDepth) {
	LOpen = (P.*Consumer)();
	return false;
	}

	return diagnoseOverflow();
	}

	bool expectAndConsume(unsigned DiagID,
	const char *Msg = "",
	tok::TokenKind SkipToTok = tok::unknown);
	bool consumeClose() {
	if (P.Tok.is(Close)) {
	LClose = (P.*Consumer)();
	return false;
	}

	return diagnoseMissingClose();
	}
	void skipToEnd();
	};

	} // end namespace clang

	#endif