[libc-commits] [libc] [libc] wcscat implementation (PR #142243)

[Michael Jones via libc-commits]

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@@ -0,0 +1,29 @@
+//===-- Implementation of wcscat ------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/wchar/wcscat.h"
+
+#include "hdr/types/size_t.h"
+#include "hdr/types/wchar_t.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+#include "src/string/string_utils.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(wchar_t *, wcscat,
+                   (wchar_t *__restrict s1, const wchar_t *__restrict s2)) {
+  size_t size_1 = internal::string_length(s1);
+  size_t size_2 = internal::string_length(s2);
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michaelrj-google wrote:

since `string_length` just iterates through `s2`, it might be more efficient to combine that with the for loop below to avoid iterating through the same string twice.

https://github.com/llvm/llvm-project/pull/142243