[PATCH] D32213: [Sema] Use MSVC inner class behavior on Itanium

[Shoaib Meenai via Phabricator via cfe-commits]

smeenai created this revision.

Windows Itanium aims to use MSVC export and import semantics. Inner
class members shouldn't be exported on a dllexport explicit
instantiation definition of the outer class, and they shouldn't be
imported on a dllimport explicit instantiation declaration of the outer
class (instead a local copy should be emitted). We were doing the first
but not the second, and this mismatch can lead to link errors. Fix the
behavior and add tests for both.


https://reviews.llvm.org/D32213

Files:
  lib/Sema/SemaTemplateInstantiate.cpp
  test/CodeGenCXX/windows-itanium-dllexport.cpp


Index: test/CodeGenCXX/windows-itanium-dllexport.cpp
===================================================================
--- test/CodeGenCXX/windows-itanium-dllexport.cpp
+++ test/CodeGenCXX/windows-itanium-dllexport.cpp
@@ -1,5 +1,10 @@
 // RUN: %clang_cc1 -emit-llvm -triple i686-windows-itanium -fdeclspec %s -o - | FileCheck %s
 
+#define JOIN2(x, y) x##y
+#define JOIN(x, y) JOIN2(x, y)
+#define UNIQ(name) JOIN(name, __LINE__)
+#define USEMEMFUNC(class, func) void (class::*UNIQ(use)())() { return &class::func; }
+
 struct __declspec(dllexport) s {
   void f() {}
 };
@@ -28,3 +33,23 @@
 
 // CHECK: define {{.*}} dllexport {{.*}} @_ZN1cIdEaSERKS0_
 // CHECK: define {{.*}} dllexport {{.*}} @_ZN1cIdE1fEv
+
+template <class T>
+struct outer {
+  void f() {}
+  struct inner {
+    void f() {}
+  };
+};
+
+template class __declspec(dllexport) outer<int>;
+
+// CHECK: define {{.*}} dllexport {{.*}} @_ZN5outerIiE1fEv
+// CHECK-NOT: define {{.*}} dllexport {{.*}} @_ZN5outerIiE5inner1fEv
+
+extern template class __declspec(dllimport) outer<char>;
+USEMEMFUNC(outer<char>, f)
+USEMEMFUNC(outer<char>::inner, f)
+
+// CHECK: declare dllimport {{.*}} @_ZN5outerIcE1fEv
+// CHECK: define {{.*}} @_ZN5outerIcE5inner1fEv
Index: lib/Sema/SemaTemplateInstantiate.cpp
===================================================================
--- lib/Sema/SemaTemplateInstantiate.cpp
+++ lib/Sema/SemaTemplateInstantiate.cpp
@@ -2605,10 +2605,11 @@
                                                 == TSK_ExplicitSpecialization)
         continue;
 
-      if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
+      if ((Context.getTargetInfo().getCXXABI().isMicrosoft() ||
+           Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment()) &&
           TSK == TSK_ExplicitInstantiationDeclaration) {
-        // In MSVC mode, explicit instantiation decl of the outer class doesn't
-        // affect the inner class.
+        // In MSVC and Windows Itanium mode, explicit instantiation decl of the
+        // outer class doesn't affect the inner class.
         continue;
       }
 


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