Re-reapply "[IR] Move optional data in llvm::Function into a hungoff uselist"

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

diff --git a/include/llvm/IR/GlobalVariable.h b/include/llvm/IR/GlobalVariable.h
index 7b291605d45b813f012d2f686382a95322ade4ce..342bdc01bfbdca7f46edec7851abd855ae071941 100644 (file)
--- a/include/llvm/IR/GlobalVariable.h
+++ b/include/llvm/IR/GlobalVariable.h
@@ -29,11 +29,10 @@ namespace llvm {
 
 class Module;
 class Constant;
-template<typename ValueSubClass, typename ItemParentClass>
-  class SymbolTableListTraits;
+template <typename ValueSubClass> class SymbolTableListTraits;
 
 class GlobalVariable : public GlobalObject, public ilist_node<GlobalVariable> {
-  friend class SymbolTableListTraits<GlobalVariable, Module>;
+  friend class SymbolTableListTraits<GlobalVariable>;
   void *operator new(size_t, unsigned) = delete;
   void operator=(const GlobalVariable &) = delete;
   GlobalVariable(const GlobalVariable &) = delete;
@@ -45,7 +44,6 @@ class GlobalVariable : public GlobalObject, public ilist_node<GlobalVariable> {
                                                // can change from its initial
                                                // value before global
                                                // initializers are run?
-
 public:
   // allocate space for exactly one operand
   void *operator new(size_t s) {
@@ -107,18 +105,13 @@ public:
   /// hasUniqueInitializer - Whether the global variable has an initializer, and
   /// any changes made to the initializer will turn up in the final executable.
   inline bool hasUniqueInitializer() const {
-    return hasInitializer() &&
-      // It's not safe to modify initializers of global variables with weak
-      // linkage, because the linker might choose to discard the initializer and
-      // use the initializer from another instance of the global variable
-      // instead. It is wrong to modify the initializer of a global variable
-      // with *_odr linkage because then different instances of the global may
-      // have different initializers, breaking the One Definition Rule.
-      !isWeakForLinker() &&
-      // It is not safe to modify initializers of global variables with the
-      // external_initializer marker since the value may be changed at runtime
-      // before C++ initializers are evaluated.
-      !isExternallyInitialized();
+    return
+        // We need to be sure this is the definition that will actually be used
+        isStrongDefinitionForLinker() &&
+        // It is not safe to modify initializers of global variables with the
+        // external_initializer marker since the value may be changed at runtime
+        // before C++ initializers are evaluated.
+        !isExternallyInitialized();
   }
 
   /// getInitializer - Return the initializer for this global variable.  It is