Decouple dllexport/dllimport from linkage

Representing dllexport/dllimport as distinct linkage types prevents using
these attributes on templates and inline functions.

Instead of introducing further mixed linkage types to include linkonce and
weak ODR, the old import/export linkage types are replaced with a new
separate visibility-like specifier:

  define available_externally dllimport void @f() {}
  @Var = dllexport global i32 1, align 4

Linkage for dllexported globals and functions is now equal to their linkage
without dllexport. Imported globals and functions must be either
declarations with external linkage, or definitions with
AvailableExternallyLinkage.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199204 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 30 insertions, 4 deletions

diff --git a/lib/Target/CppBackend/CPPBackend.cpp b/lib/Target/CppBackend/CPPBackend.cpp
index 6e2dd0a8e7..b13709914b 100644
--- a/lib/Target/CppBackend/CPPBackend.cpp
+++ b/lib/Target/CppBackend/CPPBackend.cpp
@@ -131,6 +131,7 @@ namespace {
   private:
     void printLinkageType(GlobalValue::LinkageTypes LT);
     void printVisibilityType(GlobalValue::VisibilityTypes VisTypes);
+    void printDLLStorageClassType(GlobalValue::DLLStorageClassTypes DSCType);
     void printThreadLocalMode(GlobalVariable::ThreadLocalMode TLM);
     void printCallingConv(CallingConv::ID cc);
     void printEscapedString(const std::string& str);
@@ -300,10 +301,6 @@ void CppWriter::printLinkageType(GlobalValue::LinkageTypes LT) {
     Out << "GlobalValue::AppendingLinkage"; break;
   case GlobalValue::ExternalLinkage:
     Out << "GlobalValue::ExternalLinkage"; break;
-  case GlobalValue::DLLImportLinkage:
-    Out << "GlobalValue::DLLImportLinkage"; break;
-  case GlobalValue::DLLExportLinkage:
-    Out << "GlobalValue::DLLExportLinkage"; break;
   case GlobalValue::ExternalWeakLinkage:
     Out << "GlobalValue::ExternalWeakLinkage"; break;
   case GlobalValue::CommonLinkage:
@@ -325,6 +322,21 @@ void CppWriter::printVisibilityType(GlobalValue::VisibilityTypes VisType) {
   }
 }
 
+void CppWriter::printDLLStorageClassType(
+                                    GlobalValue::DLLStorageClassTypes DSCType) {
+  switch (DSCType) {
+  case GlobalValue::DefaultStorageClass:
+    Out << "GlobalValue::DefaultStorageClass";
+    break;
+  case GlobalValue::DLLImportStorageClass:
+    Out << "GlobalValue::DLLImportStorageClass";
+    break;
+  case GlobalValue::DLLExportStorageClass:
+    Out << "GlobalValue::DLLExportStorageClass";
+    break;
+  }
+}
+
 void CppWriter::printThreadLocalMode(GlobalVariable::ThreadLocalMode TLM) {
   switch (TLM) {
     case GlobalVariable::NotThreadLocal:
@@ -1028,6 +1040,13 @@ void CppWriter::printVariableHead(const GlobalVariable *GV) {
     Out << ");";
     nl(Out);
   }
+  if (GV->getDLLStorageClass() != GlobalValue::DefaultStorageClass) {
+    printCppName(GV);
+    Out << "->setDLLStorageClass(";
+    printDLLStorageClassType(GV->getDLLStorageClass());
+    Out << ");";
+    nl(Out);
+  }
   if (GV->isThreadLocal()) {
     printCppName(GV);
     Out << "->setThreadLocalMode(";
@@ -1746,6 +1765,13 @@ void CppWriter::printFunctionHead(const Function* F) {
     Out << ");";
     nl(Out);
   }
+  if (F->getDLLStorageClass() != GlobalValue::DefaultStorageClass) {
+    printCppName(F);
+    Out << "->setDLLStorageClass(";
+    printDLLStorageClassType(F->getDLLStorageClass());
+    Out << ");";
+    nl(Out);
+  }
   if (F->hasGC()) {
     printCppName(F);
     Out << "->setGC(\"" << F->getGC() << "\");";