[PATCH] D61176: [MinGW] Do dllexport inline methods in template instantiation

[Martin Storsjö via Phabricator via cfe-commits]

mstorsjo created this revision.
mstorsjo added reviewers: rnk, hans, smeenai.
Herald added a project: clang.

Normally, in MinGW mode, inline methods aren't dllexported.

However, in the case of a dllimported template instantiation, the inline methods aren't instantiated locally, but referenced from the instantiation. Therefore, those methods also need to be dllexported, in the case of an instantiation.

GCC suffers from the same issue, reported at [1], but the issue is still unresolved there.

[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89088


Repository:
  rC Clang

https://reviews.llvm.org/D61176

Files:
  lib/Sema/SemaDeclCXX.cpp
  test/CodeGenCXX/mingw-template-dllexport.cpp


Index: test/CodeGenCXX/mingw-template-dllexport.cpp
===================================================================
--- test/CodeGenCXX/mingw-template-dllexport.cpp
+++ test/CodeGenCXX/mingw-template-dllexport.cpp
@@ -7,11 +7,9 @@
 
 template <class T>
 class c {
-  void f();
+  void f() {}
 };
 
-template <class T> void c<T>::f() {}
-
 template class __declspec(dllexport) c<int>;
 
 // CHECK: define {{.*}} dllexport {{.*}} @_ZN1cIiE1fEv
Index: lib/Sema/SemaDeclCXX.cpp
===================================================================
--- lib/Sema/SemaDeclCXX.cpp
+++ lib/Sema/SemaDeclCXX.cpp
@@ -5726,9 +5726,12 @@
         continue;
 
       if (MD->isInlined()) {
-        // MinGW does not import or export inline methods.
+        // MinGW does not import or export inline methods. But do it for
+        // template instantiations.
         if (!Context.getTargetInfo().getCXXABI().isMicrosoft() &&
-            !Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment())
+            !Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment() &&
+            TSK != TSK_ExplicitInstantiationDeclaration &&
+            TSK != TSK_ExplicitInstantiationDefinition)
           continue;
 
         // MSVC versions before 2015 don't export the move assignment operators


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