2 files changed, 39 insertions, 1 deletions
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 536c55ae4e1..97b166278f8 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -615,7 +615,20 @@ void CodeGenModule::setTLSMode(llvm::GlobalValue *GV, const VarDecl &D) const {
 }
 
 StringRef CodeGenModule::getMangledName(GlobalDecl GD) {
-  StringRef &FoundStr = MangledDeclNames[GD.getCanonicalDecl()];
+  GlobalDecl CanonicalGD = GD.getCanonicalDecl();
+
+  // Some ABIs don't have constructor variants.  Make sure that base and
+  // complete constructors get mangled the same.
+  if (const auto *CD = dyn_cast<CXXConstructorDecl>(CanonicalGD.getDecl())) {
+    if (!getTarget().getCXXABI().hasConstructorVariants()) {
+      CXXCtorType OrigCtorType = GD.getCtorType();
+      assert(OrigCtorType == Ctor_Base || OrigCtorType == Ctor_Complete);
+      if (OrigCtorType == Ctor_Base)
+        CanonicalGD = GlobalDecl(CD, Ctor_Complete);
+    }
+  }
+
+  StringRef &FoundStr = MangledDeclNames[CanonicalGD];
   if (!FoundStr.empty())
     return FoundStr;
 
diff --git a/clang/test/CodeGenCXX/mangle-ms.cpp b/clang/test/CodeGenCXX/mangle-ms.cpp
index c2a311423a9..c82fca49f61 100644
--- a/clang/test/CodeGenCXX/mangle-ms.cpp
+++ b/clang/test/CodeGenCXX/mangle-ms.cpp
@@ -454,3 +454,28 @@ namespace Complex {
 // CHECK-DAG: define void @"\01?f@Complex@@YAXU?$_Complex@H@__clang@@@Z"(
 void f(_Complex int) {}
 }
+
+namespace PR26029 {
+template <class>
+struct L {
+  L() {}
+};
+template <class>
+class H;
+struct M : L<H<int *> > {};
+
+template <class>
+struct H {};
+
+template <class GT>
+void m_fn3() {
+  (H<GT *>());
+  M();
+}
+
+void runOnFunction() {
+  L<H<int *> > b;
+  m_fn3<int>();
+}
+// CHECK-DAG: call {{.*}} @"\01??0?$L@V?$H@PAH@PR26029@@@PR26029@@QAE@XZ"
+}