Use references now that it is natural to do so.

The linker never takes ownership of a module or changes which module it
is refering to, making it natural to use references.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254449 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Linker/Linker.h

@@ -68,10 +68,10 @@ class Linker {
     InternalizeLinkedSymbols = (1 << 2)
   };
 
-  Linker(Module *M, DiagnosticHandlerFunction DiagnosticHandler);
-  Linker(Module *M);
+  Linker(Module &M, DiagnosticHandlerFunction DiagnosticHandler);
+  Linker(Module &M);
 
-  Module *getModule() const { return Composite; }
+  Module &getModule() const { return Composite; }
 
   /// \brief Link \p Src into the composite. The source is destroyed.
   /// Passing OverrideSymbols as true will have symbols from Src
@@ -80,19 +80,19 @@ class Linker {
   /// is passed. If a \p FuncToImport is provided, only that single
   /// function is imported from the source module.
   /// Returns true on error.
-  bool linkInModule(Module *Src, unsigned Flags = Flags::None,
+  bool linkInModule(Module &Src, unsigned Flags = Flags::None,
                     const FunctionInfoIndex *Index = nullptr,
                     Function *FuncToImport = nullptr);
 
-  static bool LinkModules(Module *Dest, Module *Src,
+  static bool linkModules(Module &Dest, Module &Src,
                           DiagnosticHandlerFunction DiagnosticHandler,
                           unsigned Flags = Flags::None);
 
-  static bool LinkModules(Module *Dest, Module *Src,
+  static bool linkModules(Module &Dest, Module &Src,
                           unsigned Flags = Flags::None);
 
 private:
-  Module *Composite;
+  Module &Composite;
 
   IdentifiedStructTypeSet IdentifiedStructTypes;
 

lib/LTO/LTOCodeGenerator.cpp

@@ -67,14 +67,14 @@ const char* LTOCodeGenerator::getVersionString() {
 LTOCodeGenerator::LTOCodeGenerator()
     : Context(getGlobalContext()),
       MergedModule(new Module("ld-temp.o", Context)),
-      IRLinker(new Linker(MergedModule.get())) {
+      IRLinker(new Linker(*MergedModule)) {
   initializeLTOPasses();
 }
 
 LTOCodeGenerator::LTOCodeGenerator(std::unique_ptr<LLVMContext> Context)
     : OwnedContext(std::move(Context)), Context(*OwnedContext),
       MergedModule(new Module("ld-temp.o", *OwnedContext)),
-      IRLinker(new Linker(MergedModule.get())) {
+      IRLinker(new Linker(*MergedModule)) {
   initializeLTOPasses();
 }
 
@@ -114,7 +114,7 @@ bool LTOCodeGenerator::addModule(LTOModule *Mod) {
   assert(&Mod->getModule().getContext() == &Context &&
          "Expected module in same context");
 
-  bool ret = IRLinker->linkInModule(&Mod->getModule());
+  bool ret = IRLinker->linkInModule(Mod->getModule());
 
   const std::vector<const char *> &undefs = Mod->getAsmUndefinedRefs();
   for (int i = 0, e = undefs.size(); i != e; ++i)
@@ -130,7 +130,7 @@ void LTOCodeGenerator::setModule(std::unique_ptr<LTOModule> Mod) {
   AsmUndefinedRefs.clear();
 
   MergedModule = Mod->takeModule();
-  IRLinker = make_unique<Linker>(MergedModule.get());
+  IRLinker = make_unique<Linker>(*MergedModule);
 
   const std::vector<const char*> &Undefs = Mod->getAsmUndefinedRefs();
   for (int I = 0, E = Undefs.size(); I != E; ++I)