Do not segfault when the post-dominator tree is empty (ie, there are no return

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

diff --git a/include/llvm/GlobalVariable.h b/include/llvm/GlobalVariable.h
index 66ab21c42af04b112a3d48d1c1f2dcae7da20b75..1fd004cb809e05294586054ab0fd346944863b63 100644 (file)
--- a/include/llvm/GlobalVariable.h
+++ b/include/llvm/GlobalVariable.h
@@ -14,36 +14,60 @@
 #define LLVM_GLOBAL_VARIABLE_H
 
 #include "llvm/GlobalValue.h"
+
 class Module;
-class ConstPoolVal;
+class Constant;
 class PointerType;
+template<typename SC> struct ilist_traits;
+template<typename ValueSubClass, typename ItemParentClass, typename SymTabClass,
+         typename SubClass> class SymbolTableListTraits;
 
 class GlobalVariable : public GlobalValue {
-  friend class ValueHolder<GlobalVariable, Module, Module>;
-  void setParent(Module *parent) { Parent = parent; }
+  friend class SymbolTableListTraits<GlobalVariable, Module, Module,
+                                     ilist_traits<GlobalVariable> >;
+  void setParent(Module *parent);
+
+  GlobalVariable *Prev, *Next;
+  void setNext(GlobalVariable *N) { Next = N; }
+  void setPrev(GlobalVariable *N) { Prev = N; }
 
-  bool Constant;                   // Is this a global constant?
+  bool isConstantGlobal;               // Is this a global constant?
 public:
-  GlobalVariable(const Type *Ty, bool isConstant, ConstPoolVal *Initializer = 0,
-                const string &Name = "");
-  ~GlobalVariable() {}
+  /// GlobalVariable ctor - If a parent module is specified, the global is
+  /// automatically inserted into the end of the specified modules global list.
+  ///
+  GlobalVariable(const Type *Ty, bool isConstant, LinkageTypes Linkage,
+                Constant *Initializer = 0, const std::string &Name = "",
+                 Module *Parent = 0);
 
   // Specialize setName to handle symbol table majik...
-  virtual void setName(const string &name, SymbolTable *ST = 0);
+  virtual void setName(const std::string &name, SymbolTable *ST = 0);
+
+  /// isExternal - Is this global variable lacking an initializer?  If so, the
+  /// global variable is defined in some other translation unit, and is thus
+  /// externally defined here.
+  ///
+  virtual bool isExternal() const { return Operands.empty(); }
+
+  /// hasInitializer - Unless a global variable isExternal(), it has an
+  /// initializer.  The initializer for the global variable/constant is held by
+  /// Operands[0] if an initializer is specified.
+  ///
+  inline bool hasInitializer() const { return !isExternal(); }
 
-  // The initializer for the global variable/constant is held by Operands[0] if
-  // an initializer is specified.
-  //
-  inline bool hasInitializer() const { return !Operands.empty(); }
-  inline const ConstPoolVal *getInitializer() const {
+  /// getInitializer - Return the initializer for this global variable.  It is
+  /// illegal to call this method if the global is external, because we cannot
+  /// tell what the value is initialized to!
+  ///
+  inline Constant *getInitializer() const {
     assert(hasInitializer() && "GV doesn't have initializer!");
-    return (const ConstPoolVal*)Operands[0].get();
+    return (Constant*)Operands[0].get();
   }
-  inline ConstPoolVal *getInitializer() {
+  inline Constant *getInitializer() {
     assert(hasInitializer() && "GV doesn't have initializer!");
-    return (ConstPoolVal*)Operands[0].get();
+    return (Constant*)Operands[0].get();
   }
-  inline void setInitializer(ConstPoolVal *CPV) {
+  inline void setInitializer(Constant *CPV) {
     if (CPV == 0) {
       if (hasInitializer()) Operands.pop_back();
     } else {
@@ -52,12 +76,20 @@ public:
     }
   }
 
+  // getNext/Prev - Return the next or previous global variable in the list.
+        GlobalVariable *getNext()       { return Next; }
+  const GlobalVariable *getNext() const { return Next; }
+        GlobalVariable *getPrev()       { return Prev; }
+  const GlobalVariable *getPrev() const { return Prev; }
 
-  // If the value is a global constant, its value is immutable throughout the
-  // runtime execution of the program.  Assigning a value into the constant
-  // leads to undefined behavior.
-  //
-  inline bool isConstant() const { return Constant; }
+  /// If the value is a global constant, its value is immutable throughout the
+  /// runtime execution of the program.  Assigning a value into the constant
+  /// leads to undefined behavior.
+  ///
+  bool isConstant() const { return isConstantGlobal; }
+  void setConstant(bool Value) { isConstantGlobal = Value; }
+  
+  virtual void print(std::ostream &OS) const;
 
   // Methods for support type inquiry through isa, cast, and dyn_cast:
   static inline bool classof(const GlobalVariable *) { return true; }