[libc-commits] [libc] [libc] wmemcpy implementation (PR #142070)
via libc-commits
libc-commits at lists.llvm.org
Fri May 30 11:20:11 PDT 2025
https://github.com/sribee8 updated https://github.com/llvm/llvm-project/pull/142070
>From 55d76814edb34119e10e1c00a9399761ac28d9c1 Mon Sep 17 00:00:00 2001
From: Sriya Pratipati <sriyap at google.com>
Date: Fri, 30 May 2025 00:12:43 +0000
Subject: [PATCH 1/2] [libc] wmemcpy implementation
Implemented wmemcpy and tests for the function.
---
libc/config/linux/x86_64/entrypoints.txt | 1 +
libc/include/wchar.yaml | 8 ++++
libc/src/wchar/CMakeLists.txt | 12 +++++
libc/src/wchar/wmemcpy.cpp | 26 ++++++++++
libc/src/wchar/wmemcpy.h | 23 +++++++++
libc/test/src/wchar/CMakeLists.txt | 10 ++++
libc/test/src/wchar/wmemcpy_test.cpp | 61 ++++++++++++++++++++++++
7 files changed, 141 insertions(+)
create mode 100644 libc/src/wchar/wmemcpy.cpp
create mode 100644 libc/src/wchar/wmemcpy.h
create mode 100644 libc/test/src/wchar/wmemcpy_test.cpp
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index de32b17a721dc..a7d7c2821544c 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -367,6 +367,7 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.wchar.wmemset
libc.src.wchar.wcschr
libc.src.wchar.wmemcmp
+ libc.src.wchar.wmemcpy
# sys/uio.h entrypoints
libc.src.sys.uio.writev
diff --git a/libc/include/wchar.yaml b/libc/include/wchar.yaml
index a1178ba96bd45..1c8af4cbd072d 100644
--- a/libc/include/wchar.yaml
+++ b/libc/include/wchar.yaml
@@ -50,3 +50,11 @@ functions:
- type: const wchar_t *
- type: const wchar_t *
- type: size_t
+ - name: wmemcpy
+ standards:
+ - stdc
+ return_type: wchar_t *
+ arguments:
+ - type: __restricted wchar_t *
+ - type: const __ restricted wchar_t *
+ - type: size_t
diff --git a/libc/src/wchar/CMakeLists.txt b/libc/src/wchar/CMakeLists.txt
index 43f571fed91af..86b1e418ff806 100644
--- a/libc/src/wchar/CMakeLists.txt
+++ b/libc/src/wchar/CMakeLists.txt
@@ -68,3 +68,15 @@ add_entrypoint_object(
libc.hdr.wchar_macros
libc.src.__support.wctype_utils
)
+
+add_entrypoint_object(
+ wmemcpy
+ SRCS
+ wmemcpy.cpp
+ HDRS
+ wmemcpy.h
+ DEPENDS
+ libc.hdr.types.size_t
+ libc.hdr.wchar_macros
+ libc.src.__support.wctype_utils
+)
diff --git a/libc/src/wchar/wmemcpy.cpp b/libc/src/wchar/wmemcpy.cpp
new file mode 100644
index 0000000000000..56708d6cee496
--- /dev/null
+++ b/libc/src/wchar/wmemcpy.cpp
@@ -0,0 +1,26 @@
+//===-- Implementation of wmemcpy -----------------------------------------===//
+//
+// 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/wmemcpy.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/memory_utils/inline_memcpy.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(wchar_t *, wmemcpy,
+ (wchar_t *__restrict s1, const wchar_t *__restrict s2,
+ size_t n)) {
+ inline_memcpy(s1, s2, n * sizeof(wchar_t));
+ return s1;
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/wchar/wmemcpy.h b/libc/src/wchar/wmemcpy.h
new file mode 100644
index 0000000000000..c5a11a544e11e
--- /dev/null
+++ b/libc/src/wchar/wmemcpy.h
@@ -0,0 +1,23 @@
+//===-- Implementation header for wmemcpy ---------------------------------===//
+//
+// 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_WMEMCPY_H
+#define LLVM_LIBC_SRC_WCHAR_WMEMCPY_H
+
+#include "hdr/types/size_t.h"
+#include "hdr/types/wchar_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+wchar_t *wmemcpy(wchar_t *__restrict s1, const wchar_t *__restrict s2,
+ size_t n);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_WCHAR_WMEMCPY_H
diff --git a/libc/test/src/wchar/CMakeLists.txt b/libc/test/src/wchar/CMakeLists.txt
index 05eeef0e92733..aaccac495c72a 100644
--- a/libc/test/src/wchar/CMakeLists.txt
+++ b/libc/test/src/wchar/CMakeLists.txt
@@ -64,3 +64,13 @@ add_libc_test(
DEPENDS
libc.src.wchar.wmemcmp
)
+
+add_libc_test(
+ wmemcpy_test
+ SUITE
+ libc_wchar_unittests
+ SRCS
+ wmemcpy_test.cpp
+ DEPENDS
+ libc.src.wchar.wmemcpy
+)
diff --git a/libc/test/src/wchar/wmemcpy_test.cpp b/libc/test/src/wchar/wmemcpy_test.cpp
new file mode 100644
index 0000000000000..0f17d9ab21f38
--- /dev/null
+++ b/libc/test/src/wchar/wmemcpy_test.cpp
@@ -0,0 +1,61 @@
+//===-- Unittests for wmemcpy ---------------------------------------------===//
+//
+// 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 "hdr/types/size_t.h"
+#include "hdr/types/wchar_t.h"
+#include "src/wchar/wmemcpy.h"
+#include "test/UnitTest/Test.h"
+
+TEST(LlvmLibcWMemcpyTest, CopyIntoEmpty) {
+ wchar_t dest[10] = {};
+ const wchar_t *src = L"abcde";
+ LIBC_NAMESPACE::wmemcpy(dest, src, 6);
+ ASSERT_TRUE(src[0] == dest[0]);
+ ASSERT_TRUE(src[1] == dest[1]);
+ ASSERT_TRUE(src[2] == dest[2]);
+ ASSERT_TRUE(src[3] == dest[3]);
+ ASSERT_TRUE(src[4] == dest[4]);
+ ASSERT_TRUE(src[5] == dest[5]);
+}
+
+TEST(LlvmLibcWMemcpyTest, CopyFullString) {
+ // After copying, strings should be the same.
+ wchar_t dest[10] = {};
+ const wchar_t *src = L"abcde";
+ LIBC_NAMESPACE::wmemcpy(dest, src, 6);
+ ASSERT_TRUE(src[0] == dest[0]);
+ ASSERT_TRUE(src[1] == dest[1]);
+ ASSERT_TRUE(src[2] == dest[2]);
+ ASSERT_TRUE(src[3] == dest[3]);
+ ASSERT_TRUE(src[4] == dest[4]);
+ ASSERT_TRUE(src[5] == dest[5]);
+}
+
+TEST(LlvmLibcWMemcpyTest, CopyPartialString) {
+ // After copying, only first two characters should be the same.
+ wchar_t dest[10] = {};
+ const wchar_t *src = L"abcde";
+ LIBC_NAMESPACE::wmemcpy(dest, src, 2);
+ ASSERT_TRUE(src[0] == dest[0]);
+ ASSERT_TRUE(src[1] == dest[1]);
+ ASSERT_TRUE(src[2] != dest[2]);
+ ASSERT_TRUE(src[3] != dest[3]);
+ ASSERT_TRUE(src[4] != dest[4]);
+}
+
+TEST(LlvmLibcWMemcpyTest, CopyZeroCharacters) {
+ // Copying 0 characters should not change the string
+ wchar_t dest[10] = {};
+ const wchar_t *src = L"abcde";
+ LIBC_NAMESPACE::wmemcpy(dest, src, 0);
+ ASSERT_TRUE(src[0] != dest[0]);
+ ASSERT_TRUE(src[1] != dest[1]);
+ ASSERT_TRUE(src[2] != dest[2]);
+ ASSERT_TRUE(src[3] != dest[3]);
+ ASSERT_TRUE(src[4] != dest[4]);
+}
>From acf83b39e60f4257356c417fa0697286e60e8c5b Mon Sep 17 00:00:00 2001
From: Sriya Pratipati <sriyap at google.com>
Date: Fri, 30 May 2025 18:19:54 +0000
Subject: [PATCH 2/2] Changed check for CopyZeroCharacters
---
libc/test/src/wchar/wmemcpy_test.cpp | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/libc/test/src/wchar/wmemcpy_test.cpp b/libc/test/src/wchar/wmemcpy_test.cpp
index 0f17d9ab21f38..5533eef5a9abc 100644
--- a/libc/test/src/wchar/wmemcpy_test.cpp
+++ b/libc/test/src/wchar/wmemcpy_test.cpp
@@ -50,12 +50,12 @@ TEST(LlvmLibcWMemcpyTest, CopyPartialString) {
TEST(LlvmLibcWMemcpyTest, CopyZeroCharacters) {
// Copying 0 characters should not change the string
- wchar_t dest[10] = {};
+ wchar_t dest[10] = {L'1', L'2', L'3', L'4', L'5', L'\0'};
const wchar_t *src = L"abcde";
LIBC_NAMESPACE::wmemcpy(dest, src, 0);
- ASSERT_TRUE(src[0] != dest[0]);
- ASSERT_TRUE(src[1] != dest[1]);
- ASSERT_TRUE(src[2] != dest[2]);
- ASSERT_TRUE(src[3] != dest[3]);
- ASSERT_TRUE(src[4] != dest[4]);
+ ASSERT_TRUE(L'1' == dest[0]);
+ ASSERT_TRUE(L'2' == dest[1]);
+ ASSERT_TRUE(L'3' == dest[2]);
+ ASSERT_TRUE(L'4' == dest[3]);
+ ASSERT_TRUE(L'5' == dest[4]);
}
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