Backout r66408, we don't want handling of globals to rely on the

module symbol table. The root problem inspiring this was fixed in
r66316 (and again in r66506).

llvm-svn: 66512

clang/lib/CodeGen/CodeGenModule.cpp

@@ -788,8 +788,7 @@ void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) {
 
 llvm::GlobalValue *
 CodeGenModule::EmitForwardFunctionDefinition(const FunctionDecl *D,
-                                             const llvm::Type *Ty,
-                                             bool ReplaceExisting) {
+                                             const llvm::Type *Ty) {
   bool DoSetAttributes = true;
   if (!Ty) {
     Ty = getTypes().ConvertType(D->getType());
@@ -802,13 +801,10 @@ CodeGenModule::EmitForwardFunctionDefinition(const FunctionDecl *D,
       DoSetAttributes = false;
     }
   }
-  const char *Name = getMangledName(D);
-  llvm::Function *F = getModule().getFunction(Name);
-  if (ReplaceExisting || !F || !F->hasExternalLinkage())
-    F = llvm::Function::Create(cast<llvm::FunctionType>(Ty), 
-                               llvm::Function::ExternalLinkage,
-                               Name,
-                               &getModule());
+  llvm::Function *F = llvm::Function::Create(cast<llvm::FunctionType>(Ty), 
+                                             llvm::Function::ExternalLinkage,
+                                             getMangledName(D),
+                                             &getModule());
   if (DoSetAttributes)
     SetFunctionAttributes(D, F);
   return F;
@@ -842,33 +838,33 @@ void CodeGenModule::EmitGlobalFunctionDefinition(const FunctionDecl *D) {
   llvm::GlobalValue *&Entry = GlobalDeclMap[getMangledName(D)];
   if (!Entry) {
     Entry = EmitForwardFunctionDefinition(D, Ty);
-  }
-
-  // If the types mismatch then we have to rewrite the definition.
-  if (Entry->getType() != llvm::PointerType::getUnqual(Ty)) {
-    // Otherwise, we have a definition after a prototype with the
-    // wrong type.  F is the Function* for the one with the wrong
-    // type, we must make a new Function* and update everything that
-    // used F (a declaration) with the new Function* (which will be
-    // a definition).
-    //
-    // This happens if there is a prototype for a function
-    // (e.g. "int f()") and then a definition of a different type
-    // (e.g. "int f(int x)").  Start by making a new function of the
-    // correct type, RAUW, then steal the name.
-    llvm::GlobalValue *NewFn = EmitForwardFunctionDefinition(D, Ty, true);
-    NewFn->takeName(Entry);
-  
-    // Replace uses of F with the Function we will endow with a body.
-    llvm::Constant *NewPtrForOldDecl = 
-      llvm::ConstantExpr::getBitCast(NewFn, Entry->getType());
-    Entry->replaceAllUsesWith(NewPtrForOldDecl);
-
-    // Ok, delete the old function now, which is dead.
-    assert(Entry->isDeclaration() && "Shouldn't replace non-declaration");
-    Entry->eraseFromParent();
-
-    Entry = NewFn;
+  } else {
+    // If the types mismatch then we have to rewrite the definition.
+    if (Entry->getType() != llvm::PointerType::getUnqual(Ty)) {
+      // Otherwise, we have a definition after a prototype with the
+      // wrong type.  F is the Function* for the one with the wrong
+      // type, we must make a new Function* and update everything that
+      // used F (a declaration) with the new Function* (which will be
+      // a definition).
+      //
+      // This happens if there is a prototype for a function
+      // (e.g. "int f()") and then a definition of a different type
+      // (e.g. "int f(int x)").  Start by making a new function of the
+      // correct type, RAUW, then steal the name.
+      llvm::GlobalValue *NewFn = EmitForwardFunctionDefinition(D, Ty);
+      NewFn->takeName(Entry);
+      
+      // Replace uses of F with the Function we will endow with a body.
+      llvm::Constant *NewPtrForOldDecl = 
+        llvm::ConstantExpr::getBitCast(NewFn, Entry->getType());
+      Entry->replaceAllUsesWith(NewPtrForOldDecl);
+            
+      // Ok, delete the old function now, which is dead.
+      assert(Entry->isDeclaration() && "Shouldn't replace non-declaration");
+      Entry->eraseFromParent();
+      
+      Entry = NewFn;
+    }
   }
 
   llvm::Function *Fn = cast<llvm::Function>(Entry);    

clang/lib/CodeGen/CodeGenModule.h

@@ -312,17 +312,14 @@ private:
 
   void EmitGlobalDefinition(const ValueDecl *D);
 
-  /// EmitForwardFunctionDefinition - Create a new function for the given decl
-  /// and set attributes as appropriate if ReplaceExisting is true, or if the
-  /// same named declaration doesn't already exist in the module table,
-  /// otherwise return the existing function from the module table.
+  /// EmitForwardFunctionDefinition - Create a new function for the
+  /// given decl and set attributes as appropriate.
   ///
-  /// \arg Ty - If non-null the LLVM function type to use for the decl; it is
-  /// the callers responsibility to make sure this is compatible with the
-  /// correct type.
+  /// \arg Ty - If non-null the LLVM function type to use for the
+  /// decl; it is the callers responsibility to make sure this is
+  /// compatible with the correct type.
   llvm::GlobalValue *EmitForwardFunctionDefinition(const FunctionDecl *D,
-                                                   const llvm::Type *Ty,
-                                                   bool ReplaceExisting=false);
+                                                   const llvm::Type *Ty);
 
   void EmitGlobalFunctionDefinition(const FunctionDecl *D);
   void EmitGlobalVarDefinition(const VarDecl *D);
@@ -340,19 +337,19 @@ private:
   void EmitAliases(void);
   void EmitAnnotations(void);
 
-  /// EmitDeferred - Emit any needed decls for which code generation was
-  /// deferred.
+  /// EmitDeferred - Emit any needed decls for which code generation
+  /// was deferred.
   void EmitDeferred(void);
 
-  /// EmitLLVMUsed - Emit the llvm.used metadata used to force references to
-  /// global which may otherwise be optimized out.
+  /// EmitLLVMUsed - Emit the llvm.used metadata used to force
+  /// references to global which may otherwise be optimized out.
   void EmitLLVMUsed(void);
 
   void BindRuntimeGlobals();
 
-  /// MayDeferGeneration - Determine if the given decl can be emitted lazily;
-  /// this is only relevant for definitions. The given decl must be either a
-  /// function or var decl.
+  /// MayDeferGeneration - Determine if the given decl can be emitted
+  /// lazily; this is only relevant for definitions. The given decl
+  /// must be either a function or var decl.
   bool MayDeferGeneration(const ValueDecl *D);
 };
 }  // end namespace CodeGen