From: Douglas Gregor <dgregor@apple.com>
Date: Mon, 21 Jun 2010 18:41:26 +0000 (+0000)
Subject: Instantiations subject to an explicit template instantiation
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=af896897f7485176f43d40c4adced7efb0fb2b06;p=clang

Instantiations subject to an explicit template instantiation
declaration have default visibility even under
-fvisibility=hidden. Fixes <rdar://problem/8109763>.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@106440 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index 28f73d688c..a9a55bfd15 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -23,6 +23,7 @@
 #include "clang/AST/CharUnits.h"
 #include "clang/AST/DeclObjC.h"
 #include "clang/AST/DeclCXX.h"
+#include "clang/AST/DeclTemplate.h"
 #include "clang/AST/RecordLayout.h"
 #include "clang/Basic/Builtins.h"
 #include "clang/Basic/Diagnostic.h"
@@ -151,14 +152,38 @@ CodeGenModule::getDeclVisibilityMode(const Decl *D) const {
       return LangOptions::Protected;
     }
   }
-
-  // If -fvisibility-inlines-hidden was provided, then inline C++ member
-  // functions get "hidden" visibility by default.
-  if (getLangOptions().InlineVisibilityHidden)
-    if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D))
-      if (Method->isInlined())
-        return LangOptions::Hidden;
   
+  if (getLangOptions().CPlusPlus) {
+    // Entities subject to an explicit instantiation declaration get default
+    // visibility.
+    if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) {
+      if (Function->getTemplateSpecializationKind()
+                                        == TSK_ExplicitInstantiationDeclaration)
+        return LangOptions::Default;
+    } else if (const ClassTemplateSpecializationDecl *ClassSpec
+                              = dyn_cast<ClassTemplateSpecializationDecl>(D)) {
+      if (ClassSpec->getSpecializationKind()
+                                        == TSK_ExplicitInstantiationDeclaration)
+        return LangOptions::Default;
+    } else if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
+      if (Record->getTemplateSpecializationKind()
+                                        == TSK_ExplicitInstantiationDeclaration)
+        return LangOptions::Default;
+    } else if (const VarDecl *Var = dyn_cast<VarDecl>(D)) {
+      if (Var->isStaticDataMember() &&
+          (Var->getTemplateSpecializationKind()
+                                      == TSK_ExplicitInstantiationDeclaration))
+        return LangOptions::Default;
+    }
+
+    // If -fvisibility-inlines-hidden was provided, then inline C++ member
+    // functions get "hidden" visibility by default.
+    if (getLangOptions().InlineVisibilityHidden)
+      if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D))
+        if (Method->isInlined())
+          return LangOptions::Hidden;
+  }
+           
   // This decl should have the same visibility as its parent.
   if (const DeclContext *DC = D->getDeclContext()) 
     return getDeclVisibilityMode(cast<Decl>(DC));
diff --git a/test/CodeGenCXX/visibility-hidden-extern-templates.cpp b/test/CodeGenCXX/visibility-hidden-extern-templates.cpp
new file mode 100644
index 0000000000..4c133ec32c
--- /dev/null
+++ b/test/CodeGenCXX/visibility-hidden-extern-templates.cpp
@@ -0,0 +1,26 @@
+// RUN: %clang_cc1 -emit-llvm -o - -fvisibility hidden %s | FileCheck %s
+
+template<typename T>
+struct X {
+  void f();
+  void g() { }
+};
+
+template<typename T> void X<T>::f() { }
+
+extern template struct X<int>;
+template struct X<int>;
+extern template struct X<char>;
+
+// <rdar://problem/8109763>
+void test_X(X<int> xi, X<char> xc) {
+  // CHECK: define weak_odr hidden void @_ZN1XIiE1fEv
+  xi.f();
+  // CHECK: define weak_odr hidden void @_ZN1XIiE1gEv
+  xi.g();
+  // CHECK: declare void @_ZN1XIcE1fEv
+  xc.f();
+  // CHECK: define available_externally void @_ZN1XIcE1gEv
+  xc.g();
+}
+