[libc-commits] [libc] [libc] add `LLVM_LIBC_CAST` macro. (PR #127319)

[via libc-commits]

https://github.com/c8ef created https://github.com/llvm/llvm-project/pull/127319

related: #127238

This patch adds a macro called `LLVM_LIBC_CAST`, similar to `__BIONIC_CAST`, for type conversion in `endian.h`.

>From 866374c4fb133bcb3d22b3ce2dfcbc9fb7559dac Mon Sep 17 00:00:00 2001
From: c8ef <c8ef at outlook.com>
Date: Sat, 15 Feb 2025 20:56:03 +0800
Subject: [PATCH] add LLVM_LIBC_CAST macro

---
 libc/include/__llvm-libc-common.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libc/include/__llvm-libc-common.h b/libc/include/__llvm-libc-common.h
index a0fa506c01ab8..83682e0a440d8 100644
--- a/libc/include/__llvm-libc-common.h
+++ b/libc/include/__llvm-libc-common.h
@@ -47,6 +47,9 @@
 #define __NOEXCEPT throw()
 #endif
 
+#undef LLVM_LIBC_CAST
+#define LLVM_LIBC_CAST(cast, type, value) (cast<type>(value))
+
 #else // not __cplusplus
 
 #undef __BEGIN_C_DECLS
@@ -85,6 +88,9 @@
 #undef _Returns_twice
 #define _Returns_twice __attribute__((returns_twice))
 
+#undef LLVM_LIBC_CAST
+#define LLVM_LIBC_CAST(cast, type, value) ((type)(value))
+
 #endif // __cplusplus
 
 #endif // LLVM_LIBC_COMMON_H