ApplyIRLinkage cleanups

include/swift/IRGen/Linking.h

@@ -1043,31 +1043,35 @@ struct IRLinkage {
   llvm::GlobalValue::DLLStorageClassTypes DLLStorage;
 
   static const IRLinkage InternalLinkOnceODR;
+  static const IRLinkage InternalWeakODR;
   static const IRLinkage Internal;
+
+  static const IRLinkage ExternalImport;
+  static const IRLinkage ExternalExport;
 };
 
 class ApplyIRLinkage {
   IRLinkage IRL;
 public:
   ApplyIRLinkage(IRLinkage IRL) : IRL(IRL) {}
   void to(llvm::GlobalValue *GV) const {
+    llvm::Module *M = GV->getParent();
+    const llvm::Triple Triple(M->getTargetTriple());
+
     GV->setLinkage(IRL.Linkage);
     GV->setVisibility(IRL.Visibility);
-    GV->setDLLStorageClass(IRL.DLLStorage);
-
-    if (IRL.Linkage == llvm::GlobalValue::LinkOnceODRLinkage ||
-        IRL.Linkage == llvm::GlobalValue::WeakODRLinkage) {
-      llvm::Module *M = GV->getParent();
-      const llvm::Triple Triple(M->getTargetTriple());
+    if (Triple.isOSBinFormatCOFF() && !Triple.isOSCygMing())
+      GV->setDLLStorageClass(IRL.DLLStorage);
 
-      // TODO: BFD and gold do not handle COMDATs properly
-      if (Triple.isOSBinFormatELF())
-        return;
+    // TODO: BFD and gold do not handle COMDATs properly
+    if (Triple.isOSBinFormatELF())
+      return;
 
+    if (IRL.Linkage == llvm::GlobalValue::LinkOnceODRLinkage ||
+        IRL.Linkage == llvm::GlobalValue::WeakODRLinkage)
       if (Triple.supportsCOMDAT())
         if (llvm::GlobalObject *GO = dyn_cast<llvm::GlobalObject>(GV))
           GO->setComdat(M->getOrInsertComdat(GV->getName()));
-    }
   }
 };
 

lib/IRGen/GenDecl.cpp

@@ -1410,9 +1410,8 @@ void IRGenModule::emitVTableStubs() {
 
     if (F.getEffectiveSymbolLinkage() == SILLinkage::Hidden)
       alias->setVisibility(llvm::GlobalValue::HiddenVisibility);
-
-    if (useDllStorage())
-      alias->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
+    else
+      ApplyIRLinkage(IRLinkage::ExternalExport).to(alias);
   }
 }
 

lib/IRGen/GenFunc.cpp

@@ -77,6 +77,7 @@
 #include "swift/AST/PrettyStackTrace.h"
 #include "swift/AST/SubstitutionMap.h"
 #include "swift/AST/Types.h"
+#include "swift/IRGen/Linking.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/CodeGen/CodeGenABITypes.h"
 #include "llvm/IR/Constants.h"
@@ -1621,9 +1622,8 @@ void irgen::emitBlockHeader(IRGenFunction &IGF,
   auto NSConcreteStackBlock =
       IGF.IGM.getModule()->getOrInsertGlobal("_NSConcreteStackBlock",
                                              IGF.IGM.ObjCClassStructTy);
-  if (IGF.IGM.useDllStorage())
-    cast<llvm::GlobalVariable>(NSConcreteStackBlock)
-        ->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
+  ApplyIRLinkage(IRLinkage::ExternalImport)
+      .to(cast<llvm::GlobalVariable>(NSConcreteStackBlock));
 
   //
   // Set the flags.

lib/IRGen/GenReflection.cpp

@@ -230,10 +230,7 @@ llvm::Constant *IRGenModule::getMangledAssociatedConformance(
                                       llvm::GlobalValue::LinkOnceODRLinkage,
                                       nullptr,
                                       symbolName);
-  ApplyIRLinkage({llvm::GlobalValue::LinkOnceODRLinkage,
-                  llvm::GlobalValue::HiddenVisibility,
-                  llvm::GlobalValue::DefaultStorageClass})
-      .to(var);
+  ApplyIRLinkage(IRLinkage::InternalLinkOnceODR).to(var);
   var->setAlignment(2);
   setTrueConstGlobal(var);
   var->setSection(getReflectionTypeRefSectionName());

lib/IRGen/IRGenModule.cpp

@@ -659,8 +659,8 @@ IRGenModule::createStringConstant(StringRef Str,
       return NAME;                                                             \
     NAME = Module.getOrInsertGlobal(SYM, FullTypeMetadataStructTy);            \
     if (useDllStorage() && !isStandardLibrary())                               \
-      cast<llvm::GlobalVariable>(NAME)->setDLLStorageClass(                    \
-          llvm::GlobalValue::DLLImportStorageClass);                           \
+      ApplyIRLinkage(IRLinkage::ExternalImport)                                \
+          .to(cast<llvm::GlobalVariable>(NAME));                               \
     return NAME;                                                               \
   }
 
@@ -681,9 +681,8 @@ llvm::Constant *IRGenModule::getObjCEmptyCachePtr() {
     // struct objc_cache _objc_empty_cache;
     ObjCEmptyCachePtr = Module.getOrInsertGlobal("_objc_empty_cache",
                                                  OpaquePtrTy->getElementType());
-    if (useDllStorage())
-      cast<llvm::GlobalVariable>(ObjCEmptyCachePtr)
-          ->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
+    ApplyIRLinkage(IRLinkage::ExternalImport)
+        .to(cast<llvm::GlobalVariable>(ObjCEmptyCachePtr));
   } else {
     // FIXME: Remove even the null value per rdar://problem/18801263
     ObjCEmptyCachePtr = llvm::ConstantPointerNull::get(OpaquePtrTy);
@@ -714,9 +713,8 @@ Address IRGenModule::getAddrOfObjCISAMask() {
   assert(TargetInfo.hasISAMasking());
   if (!ObjCISAMaskPtr) {
     ObjCISAMaskPtr = Module.getOrInsertGlobal("swift_isaMask", IntPtrTy);
-    if (useDllStorage())
-      cast<llvm::GlobalVariable>(ObjCISAMaskPtr)
-          ->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
+    ApplyIRLinkage(IRLinkage::ExternalImport)
+        .to(cast<llvm::GlobalVariable>(ObjCISAMaskPtr));
   }
   return Address(ObjCISAMaskPtr, getPointerAlignment());
 }
@@ -960,11 +958,7 @@ void IRGenModule::addLinkLibrary(const LinkLibrary &linkLib) {
     encodeForceLoadSymbolName(buf, linkLib.getName());
     auto ForceImportThunk =
         Module.getOrInsertFunction(buf, llvm::FunctionType::get(VoidTy, false));
-    ApplyIRLinkage({llvm::GlobalValue::ExternalLinkage,
-                    llvm::GlobalValue::DefaultVisibility,
-                    useDllStorage()
-                        ? llvm::GlobalValue::DLLImportStorageClass
-                        : llvm::GlobalValue::DefaultStorageClass})
+    ApplyIRLinkage(IRLinkage::ExternalImport)
         .to(cast<llvm::GlobalValue>(ForceImportThunk));
 
     buf += "_$";
@@ -975,10 +969,7 @@ void IRGenModule::addLinkLibrary(const LinkLibrary &linkLib) {
                                           /*isConstant=*/true,
                                           llvm::GlobalValue::WeakODRLinkage,
                                           ForceImportThunk, buf.str());
-      ApplyIRLinkage({llvm::GlobalValue::WeakODRLinkage,
-                      llvm::GlobalValue::HiddenVisibility,
-                      llvm::GlobalValue::DefaultStorageClass})
-          .to(ref);
+      ApplyIRLinkage(IRLinkage::InternalWeakODR).to(ref);
       auto casted = llvm::ConstantExpr::getBitCast(ref, Int8PtrTy);
       LLVMUsed.push_back(casted);
     }
@@ -1089,12 +1080,7 @@ void IRGenModule::emitAutolinkInfo() {
         llvm::Function::Create(llvm::FunctionType::get(VoidTy, false),
                                llvm::GlobalValue::ExternalLinkage, buf,
                                &Module);
-    ApplyIRLinkage({llvm::GlobalValue::ExternalLinkage,
-                    llvm::GlobalValue::DefaultVisibility,
-                    useDllStorage()
-                        ? llvm::GlobalValue::DLLExportStorageClass
-                        : llvm::GlobalValue::DefaultStorageClass})
-        .to(ForceImportThunk);
+    ApplyIRLinkage(IRLinkage::ExternalExport).to(ForceImportThunk);
 
     auto BB = llvm::BasicBlock::Create(getLLVMContext(), "", ForceImportThunk);
     llvm::IRBuilder<> IRB(BB);

lib/IRGen/Linking.cpp

@@ -37,12 +37,30 @@ const IRLinkage IRLinkage::InternalLinkOnceODR = {
   llvm::GlobalValue::DefaultStorageClass,
 };
 
+const IRLinkage IRLinkage::InternalWeakODR = {
+  llvm::GlobalValue::WeakODRLinkage,
+  llvm::GlobalValue::HiddenVisibility,
+  llvm::GlobalValue::DefaultStorageClass,
+};
+
 const IRLinkage IRLinkage::Internal = {
   llvm::GlobalValue::InternalLinkage,
   llvm::GlobalValue::DefaultVisibility,
   llvm::GlobalValue::DefaultStorageClass,
 };
 
+const IRLinkage IRLinkage::ExternalImport = {
+  llvm::GlobalValue::ExternalLinkage,
+  llvm::GlobalValue::DefaultVisibility,
+  llvm::GlobalValue::DLLImportStorageClass,
+};
+
+const IRLinkage IRLinkage::ExternalExport = {
+  llvm::GlobalValue::ExternalLinkage,
+  llvm::GlobalValue::DefaultVisibility,
+  llvm::GlobalValue::DLLExportStorageClass,
+};
+
 bool swift::irgen::useDllStorage(const llvm::Triple &triple) {
   return triple.isOSBinFormatCOFF() && !triple.isOSCygMing();
 }

lib/IRGen/MetadataRequest.cpp

@@ -248,10 +248,7 @@ llvm::Constant *IRGenModule::getAddrOfStringForMetadataRef(
                                       nullptr,
                                       symbolName);
 
-  ApplyIRLinkage({llvm::GlobalValue::LinkOnceODRLinkage,
-    llvm::GlobalValue::HiddenVisibility,
-    llvm::GlobalValue::DefaultStorageClass})
-  .to(var);
+  ApplyIRLinkage(IRLinkage::InternalLinkOnceODR).to(var);
   if (alignment)
     var->setAlignment(alignment);
   setTrueConstGlobal(var);