Reland r312224 - [ItaniumCXXABI] Always use linkonce_odr linkage for RTTI data on...

This fixes cases where dynamic classes produced RTTI data with
external linkage, producing linker errors about duplicate symbols.

This touches code close to what was changed in SVN r244266, but
this change doesn't break the tests added in that revision.

The previous version had missed to update CodeGenCXX/virt-dtor-key.cpp,
which had a behaviour change only when running the testsuite on windows.

Differential revision: https://reviews.llvm.org/D37327

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@312306 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/ItaniumCXXABI.cpp b/lib/CodeGen/ItaniumCXXABI.cpp
index d78c032cec88a100ba88be6be3402f3b8208480d..e07dbdd3abd0e435c55789a8d16730e768a03bbf 100644 (file)
--- a/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/lib/CodeGen/ItaniumCXXABI.cpp
@@ -2998,15 +2998,13 @@ static llvm::GlobalVariable::LinkageTypes getTypeInfoLinkage(CodeGenModule &CGM,
         if (RD->hasAttr<DLLImportAttr>() &&
             ShouldUseExternalRTTIDescriptor(CGM, Ty))
           return llvm::GlobalValue::ExternalLinkage;
-      if (RD->isDynamicClass()) {
-        llvm::GlobalValue::LinkageTypes LT = CGM.getVTableLinkage(RD);
-        // MinGW won't export the RTTI information when there is a key function.
-        // Make sure we emit our own copy instead of attempting to dllimport it.
-        if (RD->hasAttr<DLLImportAttr>() &&
-            llvm::GlobalValue::isAvailableExternallyLinkage(LT))
-          LT = llvm::GlobalValue::LinkOnceODRLinkage;
-        return LT;
-      }
+      // MinGW always uses LinkOnceODRLinkage for type info.
+      if (RD->isDynamicClass() &&
+          !CGM.getContext()
+               .getTargetInfo()
+               .getTriple()
+               .isWindowsGNUEnvironment())
+        return CGM.getVTableLinkage(RD);
     }
 
     return llvm::GlobalValue::LinkOnceODRLinkage;

diff --git a/test/CodeGenCXX/rtti-mingw64.cpp b/test/CodeGenCXX/rtti-mingw64.cpp
index 818b11b64bc53f946e9821d1ce0b0d406d8dd8cc..9f3e03961e89184092e7e0d377b4867aa8f3a27e 100644 (file)
--- a/test/CodeGenCXX/rtti-mingw64.cpp
+++ b/test/CodeGenCXX/rtti-mingw64.cpp
@@ -2,7 +2,12 @@
 struct A { int a; };
 struct B : virtual A { int b; };
 B b;
+class C {
+  virtual ~C();
+};
+C::~C() {}
 
+// CHECK: @_ZTI1C = linkonce_odr
 // CHECK: @_ZTI1B = linkonce_odr constant { i8*, i8*, i32, i32, i8*, i64 }
 // CHECK-SAME:  i8* bitcast (i8** getelementptr inbounds (i8*, i8** @_ZTVN10__cxxabiv121__vmi_class_type_infoE, i64 2) to i8*),
 // CHECK-SAME:  i8* getelementptr inbounds ([3 x i8], [3 x i8]* @_ZTS1B, i32 0, i32 0),

diff --git a/test/CodeGenCXX/virt-dtor-key.cpp b/test/CodeGenCXX/virt-dtor-key.cpp
index 40c5a537cc539fccff6002ca477db2d4b7b8477f..d1055d4e30ca55796b8e2c9d9ec528781d0f88f1 100644 (file)
--- a/test/CodeGenCXX/virt-dtor-key.cpp
+++ b/test/CodeGenCXX/virt-dtor-key.cpp
@@ -1,5 +1,7 @@
-// RUN: %clang_cc1 -triple %itanium_abi_triple -emit-llvm %s -o - | FileCheck %s
+// RUN: %clang_cc1 -triple i386-linux -emit-llvm %s -o - | FileCheck %s
+// RUN: %clang_cc1 -triple i386-windows-gnu -emit-llvm %s -o - | FileCheck %s -check-prefix CHECK-MINGW
 // CHECK: @_ZTI3foo = constant
+// CHECK-MINGW: @_ZTI3foo = linkonce_odr
 class foo {
    foo();
    virtual ~foo();