[libc-commits] [libc] bd9e922 - [libc][AArch64] Avoid -Wshadow warnings about uint128_t etc (#212227)

[via libc-commits]

Author: Simon Tatham
Date: 2026-07-27T14:31:31+01:00
New Revision: bd9e922d448ce6a492b1b323c359b7c8a4030ad9

URL: https://github.com/llvm/llvm-project/commit/bd9e922d448ce6a492b1b323c359b7c8a4030ad9
DIFF: https://github.com/llvm/llvm-project/commit/bd9e922d448ce6a492b1b323c359b7c8a4030ad9.diff

LOG: [libc][AArch64] Avoid -Wshadow warnings about uint128_t etc (#212227)

`aarch64/inline_memset.h` defines type aliases `uint128_t`, `uint256_t`
and `uint512_t` at file scope. `aarch64/inline_memmove.h`, alongside it,
defines the same aliases at function scope. If both headers are included
by the same source file, this can lead to a warning about the
function-scope aliases shadowing the file-scope ones, which turns into a
compile error if you build with `clang -Werror -Wshadow`.

Commit a81db64570f94c2 (PR #210895) exposed this latent compile failure,
by making `CPP/string.h` include both files. But there's nothing wrong
with that, so the right fix is to make it _safe_ to include both files,
not to stop doing it.

This commit moves the function-scope aliases in memmove up to file
scope. That makes them duplicate definitions in the _same_ scope, which
doesn't cause the same error.

Other options would be to move the memset aliases down into function
scope (duplicating them in two functions), or to move them into a tiny
AArch64-specific header file with an include guard. Both of those are
more intrusive than this fix.

Added: 
    

Modified: 
    libc/src/string/memory_utils/aarch64/inline_memmove.h

Removed: 
    


################################################################################
diff  --git a/libc/src/string/memory_utils/aarch64/inline_memmove.h b/libc/src/string/memory_utils/aarch64/inline_memmove.h
index d8d276966fd27..6f5f53029985a 100644
--- a/libc/src/string/memory_utils/aarch64/inline_memmove.h
+++ b/libc/src/string/memory_utils/aarch64/inline_memmove.h
@@ -17,10 +17,11 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
+using uint128_t = generic_v128;
+using uint256_t = generic_v256;
+using uint512_t = generic_v512;
+
 LIBC_INLINE void inline_memmove_aarch64(Ptr dst, CPtr src, size_t count) {
-  using uint128_t = generic_v128;
-  using uint256_t = generic_v256;
-  using uint512_t = generic_v512;
   if (count == 0)
     return;
   if (count == 1)