Don't crash-on-valid when an inline function is friend of class template

We assumed that the most recent declaration of an inline function would
also be inline.  However, a more recent declaration can come from a
friend declaration in a class template that is instantiated at the
definition of the function.

llvm-svn: 232786

3 files changed, 18 insertions, 2 deletions

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 932bc1cb86d..89e1d52c643 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -7911,7 +7911,7 @@ static GVALinkage basicGVALinkageForFunction(const ASTContext &Context,
   // Functions specified with extern and inline in -fms-compatibility mode
   // forcibly get emitted.  While the body of the function cannot be later
   // replaced, the function definition cannot be discarded.
-  if (FD->getMostRecentDecl()->isMSExternInline())
+  if (FD->isMSExternInline())
     return GVA_StrongODR;
 
   return GVA_DiscardableODR;
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index a7e879e04c8..e700cf85997 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -2734,7 +2734,8 @@ bool FunctionDecl::isMSExternInline() const {
   if (!Context.getLangOpts().MSVCCompat && !hasAttr<DLLExportAttr>())
     return false;
 
-  for (const FunctionDecl *FD = this; FD; FD = FD->getPreviousDecl())
+  for (const FunctionDecl *FD = getMostRecentDecl(); FD;
+       FD = FD->getPreviousDecl())
     if (FD->getStorageClass() == SC_Extern)
       return true;
 
diff --git a/clang/test/CodeGenCXX/inline-functions.cpp b/clang/test/CodeGenCXX/inline-functions.cpp
index 622cfa9536f..20da1f63180 100644
--- a/clang/test/CodeGenCXX/inline-functions.cpp
+++ b/clang/test/CodeGenCXX/inline-functions.cpp
@@ -121,3 +121,18 @@ struct TypeWithInlineMethods {
   // CHECK-NOT: _ZN21TypeWithInlineMethods12NonStaticFunEv
   void NonStaticFun() { StaticFun(); }
 };
+
+namespace PR22959 {
+template <typename>
+struct S;
+
+S<int> Foo();
+
+template <typename>
+struct S {
+  friend S<int> Foo();
+};
+
+__attribute__((used)) inline S<int> Foo() { return S<int>(); }
+// CHECK-LABEL: define linkonce_odr void @_ZN7PR229593FooEv(
+}