Tweak the semantics of FunctionDecl::isOutOfLine to consider an
instantiation of a member function template or member function of a
class template to be out-of-line if the definition of that function
template or member function was defined out-of-line. This ensures that
we get the correct linkage for explicit instantiations of out-of-line
definitions. 

llvm-svn: 81562
diff --git a/clang/include/clang/AST/Decl.h b/clang/include/clang/AST/Decl.h
index ee3ddb0..01276ba 100644
--- a/clang/include/clang/AST/Decl.h
+++ b/clang/include/clang/AST/Decl.h
@@ -1137,6 +1137,10 @@
   /// represents.
   void setTemplateSpecializationKind(TemplateSpecializationKind TSK);
 
+  /// \brief Determine whether this is or was instantiated from an out-of-line 
+  /// definition of a member function.
+  bool isOutOfLine() const;
+                       
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) {
     return D->getKind() >= FunctionFirst && D->getKind() <= FunctionLast;
diff --git a/clang/include/clang/AST/DeclCXX.h b/clang/include/clang/AST/DeclCXX.h
index 23da3e0..7fd7ee6 100644
--- a/clang/include/clang/AST/DeclCXX.h
+++ b/clang/include/clang/AST/DeclCXX.h
@@ -757,7 +757,7 @@
     return isVirtualAsWritten() ||
       (begin_overridden_methods() != end_overridden_methods());
   }
-
+  
   ///
   void addOverriddenMethod(const CXXMethodDecl *MD);
 
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 8fd6ebf..a7d8216 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -704,6 +704,30 @@
   Info->setTemplateSpecializationKind(TSK);
 }
 
+bool FunctionDecl::isOutOfLine() const {
+  // FIXME: Should we restrict this to member functions?
+  if (Decl::isOutOfLine())
+    return true;
+  
+  // If this function was instantiated from a member function of a 
+  // class template, check whether that member function was defined out-of-line.
+  if (FunctionDecl *FD = getInstantiatedFromMemberFunction()) {
+    const FunctionDecl *Definition;
+    if (FD->getBody(Definition))
+      return Definition->isOutOfLine();
+  }
+  
+  // If this function was instantiated from a function template,
+  // check whether that function template was defined out-of-line.
+  if (FunctionTemplateDecl *FunTmpl = getPrimaryTemplate()) {
+    const FunctionDecl *Definition;
+    if (FunTmpl->getTemplatedDecl()->getBody(Definition))
+      return Definition->isOutOfLine();
+  }
+  
+  return false;
+}
+
 //===----------------------------------------------------------------------===//
 // TagDecl Implementation
 //===----------------------------------------------------------------------===//
diff --git a/clang/lib/AST/DeclCXX.cpp b/clang/lib/AST/DeclCXX.cpp
index e8f97a3..073ef94 100644
--- a/clang/lib/AST/DeclCXX.cpp
+++ b/clang/lib/AST/DeclCXX.cpp
@@ -344,7 +344,6 @@
                                isStatic, isInline);
 }
 
-
 typedef llvm::DenseMap<const CXXMethodDecl*,
                        std::vector<const CXXMethodDecl *> *>
                        OverriddenMethodsMapTy;
diff --git a/clang/test/CodeGenCXX/explicit-instantiation.cpp b/clang/test/CodeGenCXX/explicit-instantiation.cpp
index 33cbf7f..8a9e65c 100644
--- a/clang/test/CodeGenCXX/explicit-instantiation.cpp
+++ b/clang/test/CodeGenCXX/explicit-instantiation.cpp
@@ -1,9 +1,6 @@
-// RUN: clang-cc -emit-llvm -femit-all-decls -o %t %s &&
-// RUN: grep "_ZNK4plusIillEclERKiRKl" %t | count 1
+// RUN: clang-cc -emit-llvm -triple i686-pc-linue-gnu -o %t %s &&
+// RUN: grep "define i32 @_ZNK4plusIillEclERKiRKl" %t | count 1
 
-// FIXME: We should not need the -femit-all-decls, because operator() should
-// be emitted as an external symbol rather than with linkonce_odr linkage.
-// This is a Sema problem.
 template<typename T, typename U, typename Result>
 struct plus {
   Result operator()(const T& t, const U& u) const;