[llvm] [NFC][flang] Added deduction guide for StaticDescriptor class. (PR #131690)

[Slava Zakharin via llvm-commits]

https://github.com/vzakhari created https://github.com/llvm/llvm-project/pull/131690

I keep getting these warnings when building with clang-17:
`warning: 'StaticDescriptor' may not intend to support class template argument deduction [-Wctad-maybe-unsupported]`

This change should help avoiding them.


>From a48ffb73ec0a851318dc248b0c36f738896afef8 Mon Sep 17 00:00:00 2001
From: Slava Zakharin <szakharin at nvidia.com>
Date: Mon, 17 Mar 2025 16:09:22 -0700
Subject: [PATCH] [NFC][flang] Added deduction guide for StaticDescriptor
 class.

I keep getting these warnings when building with clang-17:
`warning: 'StaticDescriptor' may not intend to support class template argument deduction [-Wctad-maybe-unsupported]`

This change should help avoiding them.
---
 flang-rt/include/flang-rt/runtime/descriptor.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/flang-rt/include/flang-rt/runtime/descriptor.h b/flang-rt/include/flang-rt/runtime/descriptor.h
index 19e1a0bf6a1dd..dcdfe073a708d 100644
--- a/flang-rt/include/flang-rt/runtime/descriptor.h
+++ b/flang-rt/include/flang-rt/runtime/descriptor.h
@@ -481,5 +481,8 @@ class alignas(Descriptor) StaticDescriptor {
   char storage_[byteSize]{};
 };
 
+// Deduction guide to avoid warnings from older versions of clang.
+StaticDescriptor() -> StaticDescriptor<maxRank, false, 0>;
+
 } // namespace Fortran::runtime
 #endif // FLANG_RT_RUNTIME_DESCRIPTOR_H_