[libc] Implemented wcsdup libc function (#150453)

Implemented wcsdup by templating internal strdup function

4 files changed, 64 insertions, 3 deletions

diff --git a/libc/src/string/allocating_string_utils.h b/libc/src/string/allocating_string_utils.h
index 1dece510e796..e2f61f77b0c7 100644
--- a/libc/src/string/allocating_string_utils.h
+++ b/libc/src/string/allocating_string_utils.h
@@ -20,15 +20,15 @@
 namespace LIBC_NAMESPACE_DECL {
 namespace internal {
 
-LIBC_INLINE cpp::optional<char *> strdup(const char *src) {
+template <typename T> LIBC_INLINE cpp::optional<T *> strdup(const T *src) {
   if (src == nullptr)
     return cpp::nullopt;
   size_t len = string_length(src) + 1;
   AllocChecker ac;
-  char *newstr = new (ac) char[len];
+  T *newstr = new (ac) T[len];
   if (!ac)
     return cpp::nullopt;
-  inline_memcpy(newstr, src, len);
+  inline_memcpy(newstr, src, len * sizeof(T));
   return newstr;
 }
 
diff --git a/libc/src/wchar/CMakeLists.txt b/libc/src/wchar/CMakeLists.txt
index 2b95d94e4230..25319837bdc7 100644
--- a/libc/src/wchar/CMakeLists.txt
+++ b/libc/src/wchar/CMakeLists.txt
@@ -256,6 +256,19 @@ add_entrypoint_object(
 )
 
 add_entrypoint_object(
+  wcsdup
+  SRCS
+    wcsdup.cpp
+  HDRS
+    wcsdup.h
+  DEPENDS
+    libc.hdr.types.wchar_t
+    libc.src.__support.libc_errno
+    libc.src.__support.macros.config
+    libc.src.string.allocating_string_utils
+)
+
+add_entrypoint_object(
   wcspbrk
   SRCS
     wcspbrk.cpp
diff --git a/libc/src/wchar/wcsdup.cpp b/libc/src/wchar/wcsdup.cpp
new file mode 100644
index 000000000000..d4a13d35e4d5
--- /dev/null
+++ b/libc/src/wchar/wcsdup.cpp
@@ -0,0 +1,27 @@
+//===-- Implementation of wcsdup -----------------------------------------===//
+//
+// 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/wcsdup.h"
+#include "hdr/types/wchar_t.h"
+#include "src/__support/common.h"
+#include "src/__support/libc_errno.h"
+#include "src/__support/macros/config.h"
+#include "src/string/allocating_string_utils.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(wchar_t *, wcsdup, (const wchar_t *wcs)) {
+  auto dup = internal::strdup(wcs);
+  if (dup)
+    return *dup;
+  if (wcs != nullptr)
+    libc_errno = ENOMEM;
+  return nullptr;
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/wchar/wcsdup.h b/libc/src/wchar/wcsdup.h
new file mode 100644
index 000000000000..80b3e52d71b9
--- /dev/null
+++ b/libc/src/wchar/wcsdup.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for wcsdup ----------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_WCHAR_WCSDUP_H
+#define LLVM_LIBC_SRC_WCHAR_WCSDUP_H
+
+#include "hdr/types/wchar_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+wchar_t *wcsdup(const wchar_t *wcs);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_WCHAR_WCSDUP_H