[CUDA][HIP] allow trivial ctor/dtor in device var init (#73140)

Treat ctor/dtor in device var init as host device function
so that they can be used to initialize file-scope
device variables to match nvcc behavior. If they are non-trivial
they will be diagnosed.

We cannot add implicit host device attrs to non-trivial
ctor/dtor since determining whether they are non-trivial
needs to know whether they have a trivial body and all their
member and base classes' ctor/dtor have trivial body, which
is affected by where their bodies are defined or instantiated.

Fixes: #72261

Fixes: SWDEV-432412

1 files changed, 9 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaCUDA.cpp b/clang/lib/Sema/SemaCUDA.cpp
index 318174f..6a66ecf 100644
--- a/clang/lib/Sema/SemaCUDA.cpp
+++ b/clang/lib/Sema/SemaCUDA.cpp
@@ -225,6 +225,15 @@ Sema::CUDAFunctionPreference
 Sema::IdentifyCUDAPreference(const FunctionDecl *Caller,
                              const FunctionDecl *Callee) {
   assert(Callee && "Callee must be valid.");
+
+  // Treat ctor/dtor as host device function in device var initializer to allow
+  // trivial ctor/dtor without device attr to be used. Non-trivial ctor/dtor
+  // will be diagnosed by checkAllowedCUDAInitializer.
+  if (Caller == nullptr && CurCUDATargetCtx.Kind == CTCK_InitGlobalVar &&
+      CurCUDATargetCtx.Target == CFT_Device &&
+      (isa<CXXConstructorDecl>(Callee) || isa<CXXDestructorDecl>(Callee)))
+    return CFP_HostDevice;
+
   CUDAFunctionTarget CallerTarget = IdentifyCUDATarget(Caller);
   CUDAFunctionTarget CalleeTarget = IdentifyCUDATarget(Callee);