CodeGen, Itanium: Properly dllimport RTTI data

We would blindly assume that RTTI data should have the same linkage as
the vtable because we didn't think the RTTI data was external.  This
oversight stemmed because we didn't take dllimport into account.

This fixes PR21512.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@221511 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/ItaniumCXXABI.cpp b/lib/CodeGen/ItaniumCXXABI.cpp
index 084fd3be5b3a943f65afa6683faa480e27195e02..66ea0f6844847fa5fd62923e6b645e7e5a5f581d 100644 (file)
--- a/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/lib/CodeGen/ItaniumCXXABI.cpp
@@ -2190,6 +2190,11 @@ ItaniumRTTIBuilder::GetAddrOfExternalRTTIDescriptor(QualType Ty) {
                                   /*Constant=*/true,
                                   llvm::GlobalValue::ExternalLinkage, nullptr,
                                   Name);
+    if (const RecordType *RecordTy = dyn_cast<RecordType>(Ty)) {
+      const CXXRecordDecl *RD = cast<CXXRecordDecl>(RecordTy->getDecl());
+      if (RD->hasAttr<DLLImportAttr>())
+        GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
+    }
   }
 
   return llvm::ConstantExpr::getBitCast(GV, CGM.Int8PtrTy);
@@ -2312,7 +2317,11 @@ static bool ShouldUseExternalRTTIDescriptor(CodeGenModule &CGM,
 
     // FIXME: this may need to be reconsidered if the key function
     // changes.
-    return CGM.getVTables().isVTableExternal(RD);
+    if (CGM.getVTables().isVTableExternal(RD))
+      return true;
+
+    if (RD->hasAttr<DLLImportAttr>())
+      return true;
   }
 
   return false;

diff --git a/test/CodeGenCXX/dllimport-rtti.cpp b/test/CodeGenCXX/dllimport-rtti.cpp
index 7ed7dadfe4021ff64f7e4ba8c2071ffe0741efa9..b5a5d543d6e2cec16575574bfb4a629b57554383 100644 (file)
--- a/test/CodeGenCXX/dllimport-rtti.cpp
+++ b/test/CodeGenCXX/dllimport-rtti.cpp
@@ -1,13 +1,17 @@
-// RUN: %clang_cc1 -triple i686-windows-msvc -emit-llvm -std=c++1y -O1 -disable-llvm-optzns -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple i686-windows-msvc -emit-llvm -std=c++1y -O1 -disable-llvm-optzns -o - %s | FileCheck %s --check-prefix=MSVC
+// RUN: %clang_cc1 -triple i686-windows-gnu  -emit-llvm -std=c++1y -O1 -disable-llvm-optzns -o - %s | FileCheck %s --check-prefix=GNU
 
 struct __declspec(dllimport) S {
-  virtual void f();
+  virtual void f() {}
 } s;
-// CHECK-DAG: @"\01??_7S@@6B@" = available_externally dllimport
-// CHECK-DAG: @"\01??_R0?AUS@@@8" = linkonce_odr
-// CHECK-DAG: @"\01??_R1A@?0A@EA@S@@8" = linkonce_odr
-// CHECK-DAG: @"\01??_R2S@@8" = linkonce_odr
-// CHECK-DAG: @"\01??_R3S@@8" = linkonce_odr
+// MSVC-DAG: @"\01??_7S@@6B@" = available_externally dllimport
+// MSVC-DAG: @"\01??_R0?AUS@@@8" = linkonce_odr
+// MSVC-DAG: @"\01??_R1A@?0A@EA@S@@8" = linkonce_odr
+// MSVC-DAG: @"\01??_R2S@@8" = linkonce_odr
+// MSVC-DAG: @"\01??_R3S@@8" = linkonce_odr
+
+// GNU-DAG: @_ZTV1S = available_externally dllimport
+// GNU-DAG: @_ZTI1S = external dllimport
 
 struct U : S {
 } u;