commit f8fd82ba49827db0f6a6ba00c55a7b56b12a19fa
author Shih-wei Liao <sliao@google.com> Wed Feb 10 11:10:31 2010 -0800
committer Shih-wei Liao <sliao@google.com> Wed Feb 10 11:10:31 2010 -0800
tree 07718e23380bc08b11f5039b0d185512c657f5e9

Check in LLVM r95781.

lib/Parse/RAIIObjectsForParser.h

diff --git a/lib/Parse/RAIIObjectsForParser.h b/lib/Parse/RAIIObjectsForParser.h
new file mode 100644
index 0000000..06bbbc2
--- /dev/null
+++ b/lib/Parse/RAIIObjectsForParser.h
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+//===--- 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"
+
+namespace clang {
+  // TODO: move ParsingDeclRAIIObject here.
+  // TODO: move ParsingClassDefinition here.
+  // TODO: move TentativeParsingAction here.
+  
+  
+  /// 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 {
+    void operator=(const ExtensionRAIIObject &);     // DO NOT IMPLEMENT
+    ExtensionRAIIObject(const ExtensionRAIIObject&); // DO NOT IMPLEMENT
+    Diagnostic &Diags;
+  public:
+    ExtensionRAIIObject(Diagnostic &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;
+    }
+  };
+  
+} // end namespace clang
+
+#endif