[clang] [CUDA][HIP] warn incompatible redeclare (PR #77359)

[Yaxun Liu via cfe-commits]

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@@ -9013,6 +9013,12 @@ def err_cuda_ovl_target : Error<
   "cannot overload %select{__device__|__global__|__host__|__host__ __device__}2 function %3">;
 def note_cuda_ovl_candidate_target_mismatch : Note<
     "candidate template ignored: target attributes do not match">;
+def warn_offload_incompatible_redeclare : Warning<
+  "incompatible host/device attribute with redeclaration: "
+  "new declaration is %select{__device__|__global__|__host__|__host__ __device__}0 function, "
+  "old declaration is %select{__device__|__global__|__host__|__host__ __device__}1 function. "
+  "It will cause warning with nvcc">,
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yxsamliu wrote:

will modify the diagnostic message

https://github.com/llvm/llvm-project/pull/77359