Implement a warning diagnostic for weak vtables. Fixes PR6116.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@95472 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index cecd757..d31dbd5 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -390,6 +390,11 @@
def err_deleted_decl_not_first : Error<
"deleted definition must be first declaration">;
+def warn_weak_vtable : Warning<
+ "%0 has no out-of-line virtual method definitions; its vtable will be "
+ "emitted in every translation unit">,
+ InGroup<DiagGroup<"weak-vtables">>, DefaultIgnore;
+
// C++ exception specifications
def err_exception_spec_in_typedef : Error<
"exception specifications are not allowed in typedefs">;
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 52fc9b7..6599693 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -5002,9 +5002,16 @@
if (Record->isDependentContext() || !Record->isDefinition())
return;
- if (Record->isDynamicClass() && !S.Context.getKeyFunction(Record))
- S.ClassesWithUnmarkedVirtualMembers.push_back(std::make_pair(Record, Loc));
+ if (Record->isDynamicClass()) {
+ const CXXMethodDecl *KeyFunction = S.Context.getKeyFunction(Record);
+ if (!KeyFunction)
+ S.ClassesWithUnmarkedVirtualMembers.push_back(std::make_pair(Record, Loc));
+
+ if ((!KeyFunction || KeyFunction->getBody() && KeyFunction->isInlined()) &&
+ Record->getLinkage() == ExternalLinkage)
+ S.Diag(Record->getLocation(), diag::warn_weak_vtable) << Record;
+ }
for (DeclContext::decl_iterator D = Record->decls_begin(),
DEnd = Record->decls_end();
D != DEnd; ++D) {
diff --git a/test/SemaCXX/warn-weak-vtables.cpp b/test/SemaCXX/warn-weak-vtables.cpp
new file mode 100644
index 0000000..1ea88a5
--- /dev/null
+++ b/test/SemaCXX/warn-weak-vtables.cpp
@@ -0,0 +1,21 @@
+// RUN: %clang_cc1 %s -fsyntax-only -verify -Wweak-vtables
+
+struct A { // expected-warning {{'A' has no out-of-line virtual method definitions; its vtable will be emitted in every translation unit}}
+ virtual void f() { }
+};
+
+template<typename T> struct B {
+ virtual void f() { }
+};
+
+namespace {
+ struct C {
+ virtual void f() { }
+ };
+}
+
+void f() {
+ struct A {
+ virtual void f() { }
+ };
+}
\ No newline at end of file