Add MCAsmParser interface.

[oota-llvm.git] / include / llvm / AbstractTypeUser.h

diff --git a/include/llvm/AbstractTypeUser.h b/include/llvm/AbstractTypeUser.h
index 2b6bc3194964454c7367189918331dd340f920a2..c1216baabf8fac950ba59fcd29efd55897f0b6aa 100644 (file)
--- a/include/llvm/AbstractTypeUser.h
+++ b/include/llvm/AbstractTypeUser.h
@@ -2,32 +2,24 @@
 //
 //                     The LLVM Compiler Infrastructure
 //
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
-// The AbstractTypeUser class is an interface to be implemented by classes who
-// could possible use an abstract type.  Abstract types are denoted by the
-// isAbstract flag set to true in the Type class.  These are classes that
-// contain an Opaque type in their structure somehow.
-//
-// Classes must implement this interface so that they may be notified when an
-// abstract type is resolved.  Abstract types may be resolved into more concrete
-// types through: linking, parsing, and bytecode reading.  When this happens,
-// all of the users of the type must be updated to reference the new, more
-// concrete type.  They are notified through the AbstractTypeUser interface.
-//
-// In addition to this, AbstractTypeUsers must keep the use list of the
-// potentially abstract type that they reference up-to-date.  To do this in a
-// nice, transparent way, the PATypeHandle class is used to hold "Potentially
-// Abstract Types", and keep the use list of the abstract types up-to-date.
+// This file declares the AbstractTypeUser class.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_ABSTRACT_TYPE_USER_H
 #define LLVM_ABSTRACT_TYPE_USER_H
 
+#if !defined(LLVM_TYPE_H) && !defined(LLVM_VALUE_H)
+#error Do not include this file directly.  Include Type.h instead.
+#error Some versions of GCC (e.g. 3.4 and 4.1) can not handle the inlined method
+#error PATypeHolder::dropRef() correctly otherwise.
+#endif
+
 // This is the "master" include for <cassert> Whether this file needs it or not,
 // it must always include <cassert> for the files which include
 // llvm/AbstractTypeUser.h
@@ -41,7 +33,25 @@ namespace llvm {
 
 class Type;
 class DerivedType;
+template<typename T> struct simplify_type;
 
+/// The AbstractTypeUser class is an interface to be implemented by classes who
+/// could possibly use an abstract type.  Abstract types are denoted by the
+/// isAbstract flag set to true in the Type class.  These are classes that
+/// contain an Opaque type in their structure somewhere.
+///
+/// Classes must implement this interface so that they may be notified when an
+/// abstract type is resolved.  Abstract types may be resolved into more 
+/// concrete types through: linking, parsing, and bitcode reading.  When this 
+/// happens, all of the users of the type must be updated to reference the new,
+/// more concrete type.  They are notified through the AbstractTypeUser 
+/// interface.
+///
+/// In addition to this, AbstractTypeUsers must keep the use list of the
+/// potentially abstract type that they reference up-to-date.  To do this in a
+/// nice, transparent way, the PATypeHandle class is used to hold "Potentially
+/// Abstract Types", and keep the use list of the abstract types up-to-date.
+/// @brief LLVM Abstract Type User Representation
 class AbstractTypeUser {
 protected:
   virtual ~AbstractTypeUser();                        // Derive from me
@@ -127,6 +137,7 @@ public:
 ///
 class PATypeHolder {
   mutable const Type *Ty;
+  void destroy();
 public:
   PATypeHolder(const Type *ty) : Ty(ty) {
     addRef();
@@ -135,7 +146,7 @@ public:
     addRef();
   }
 
-  ~PATypeHolder() { dropRef(); }
+  ~PATypeHolder() { if (Ty) dropRef(); }
 
   operator Type *() const { return get(); }
   Type *get() const;
@@ -163,8 +174,24 @@ public:
 private:
   void addRef();
   void dropRef();
+  friend class TypeMapBase;
 };
 
+// simplify_type - Allow clients to treat uses just like values when using
+// casting operators.
+template<> struct simplify_type<PATypeHolder> {
+  typedef const Type* SimpleType;
+  static SimpleType getSimplifiedValue(const PATypeHolder &Val) {
+    return static_cast<SimpleType>(Val.get());
+  }
+};
+template<> struct simplify_type<const PATypeHolder> {
+  typedef const Type* SimpleType;
+  static SimpleType getSimplifiedValue(const PATypeHolder &Val) {
+    return static_cast<SimpleType>(Val.get());
+  }
+};
+  
 } // End llvm namespace
 
 #endif