[libc-commits] [libc] b184672 - [libc] Implemented wmemmove (#142245)

via libc-commits libc-commits at lists.llvm.org
Fri Jun 13 09:48:27 PDT 2025


Author: Uzair Nawaz
Date: 2025-06-13T16:48:24Z
New Revision: b184672ec7f1433e5dc698cda7e61be8a6085aa6

URL: https://github.com/llvm/llvm-project/commit/b184672ec7f1433e5dc698cda7e61be8a6085aa6
DIFF: https://github.com/llvm/llvm-project/commit/b184672ec7f1433e5dc698cda7e61be8a6085aa6.diff

LOG: [libc] Implemented wmemmove (#142245)

Implemented wmemmove and added tests

Added: 
    libc/src/wchar/wmemmove.cpp
    libc/src/wchar/wmemmove.h
    libc/test/src/wchar/wmemmove_test.cpp

Modified: 
    libc/config/linux/x86_64/entrypoints.txt
    libc/include/wchar.yaml
    libc/src/wchar/CMakeLists.txt
    libc/test/src/wchar/CMakeLists.txt

Removed: 
    


################################################################################
diff  --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index c993ef8303a59..aa2079faed409 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.btowc
     libc.src.wchar.wcslen
     libc.src.wchar.wctob
+    libc.src.wchar.wmemmove
     libc.src.wchar.wmemset
     libc.src.wchar.wcschr
     libc.src.wchar.wcsncmp

diff  --git a/libc/include/wchar.yaml b/libc/include/wchar.yaml
index 57f4f6660827e..1af15a6c112b5 100644
--- a/libc/include/wchar.yaml
+++ b/libc/include/wchar.yaml
@@ -112,6 +112,14 @@ functions:
       - type: __restrict wchar_t *
       - type: const __restrict wchar_t *
       - type: size_t
+  - name: wmemmove
+    standards:
+      - stdc
+    return_type: wchar_t *
+    arguments:
+      - type: wchar_t *
+      - type: const wchar_t *
+      - type: size_t
   - name: wcsncpy
     standards:
       - stdc

diff  --git a/libc/src/wchar/CMakeLists.txt b/libc/src/wchar/CMakeLists.txt
index 4b8802ede5f5d..491dd5b34340a 100644
--- a/libc/src/wchar/CMakeLists.txt
+++ b/libc/src/wchar/CMakeLists.txt
@@ -131,6 +131,18 @@ add_entrypoint_object(
     libc.hdr.wchar_macros
 )
 
+add_entrypoint_object(
+  wmemmove
+  SRCS
+    wmemmove.cpp
+  HDRS
+    wmemmove.h
+  DEPENDS
+    libc.hdr.types.size_t
+    libc.hdr.wchar_macros
+    libc.src.__support.macros.null_check
+)
+
 add_entrypoint_object(
   wcsncpy
   SRCS

diff  --git a/libc/src/wchar/wmemmove.cpp b/libc/src/wchar/wmemmove.cpp
new file mode 100644
index 0000000000000..3282077003bd7
--- /dev/null
+++ b/libc/src/wchar/wmemmove.cpp
@@ -0,0 +1,27 @@
+//===-- Implementation of wmemmove ----------------------------------------===//
+//
+// 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/wmemmove.h"
+
+#include "hdr/types/size_t.h"
+#include "hdr/types/wchar_t.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/null_check.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(wchar_t *, wmemmove,
+                   (wchar_t * dest, const wchar_t *src, size_t n)) {
+  LIBC_CRASH_ON_NULLPTR(dest);
+  LIBC_CRASH_ON_NULLPTR(src);
+
+  __builtin_memmove(dest, src, n * sizeof(wchar_t));
+  return dest;
+}
+
+} // namespace LIBC_NAMESPACE_DECL

diff  --git a/libc/src/wchar/wmemmove.h b/libc/src/wchar/wmemmove.h
new file mode 100644
index 0000000000000..b4c31ac7b397c
--- /dev/null
+++ b/libc/src/wchar/wmemmove.h
@@ -0,0 +1,22 @@
+//===-- Implementation header for wmemmove --------------------------------===//
+//
+// 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_WMEMMOVE_H
+#define LLVM_LIBC_SRC_WCHAR_WMEMMOVE_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 *wmemmove(wchar_t *dest, const wchar_t *src, size_t n);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_WCHAR_WMEMMOVE_H

diff  --git a/libc/test/src/wchar/CMakeLists.txt b/libc/test/src/wchar/CMakeLists.txt
index 6293e8e3d55cf..4990b6953348b 100644
--- a/libc/test/src/wchar/CMakeLists.txt
+++ b/libc/test/src/wchar/CMakeLists.txt
@@ -145,6 +145,16 @@ add_libc_test(
     libc.src.wchar.wmemcpy
 )
 
+add_libc_test(
+  wmemmove_test
+  SUITE
+    libc_wchar_unittests
+  SRCS
+    wmemmove_test.cpp
+  DEPENDS
+    libc.src.wchar.wmemmove
+)
+
 add_libc_test(
   wcsncpy_test
   SUITE

diff  --git a/libc/test/src/wchar/wmemmove_test.cpp b/libc/test/src/wchar/wmemmove_test.cpp
new file mode 100644
index 0000000000000..d23aa0f0b3af1
--- /dev/null
+++ b/libc/test/src/wchar/wmemmove_test.cpp
@@ -0,0 +1,111 @@
+//===-- Unittests for wmemmove --------------------------------------------===//
+//
+// 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/wmemmove.h"
+#include "test/UnitTest/Test.h"
+
+TEST(LlvmLibcWMemmoveTest, MoveZeroByte) {
+  wchar_t buffer[] = {L'a', L'b', L'y', L'z'};
+
+  wchar_t *ret = LIBC_NAMESPACE::wmemmove(buffer, buffer + 2, 0);
+  EXPECT_EQ(ret, buffer);
+
+  const wchar_t expected[] = {L'a', L'b', L'y', L'z'};
+  EXPECT_TRUE(buffer[0] == expected[0]);
+  EXPECT_TRUE(buffer[1] == expected[1]);
+  EXPECT_TRUE(buffer[2] == expected[2]);
+  EXPECT_TRUE(buffer[3] == expected[3]);
+}
+
+TEST(LlvmLibcWMemmoveTest, DstAndSrcPointToSameAddress) {
+  wchar_t buffer[] = {L'a', L'b'};
+
+  wchar_t *ret = LIBC_NAMESPACE::wmemmove(buffer, buffer, 1);
+  EXPECT_EQ(ret, buffer);
+
+  const wchar_t expected[] = {L'a', L'b'};
+  EXPECT_TRUE(buffer[0] == expected[0]);
+  EXPECT_TRUE(buffer[1] == expected[1]);
+}
+
+TEST(LlvmLibcWMemmoveTest, DstStartsBeforeSrc) {
+  // Set boundary at beginning and end for not overstepping when
+  // copy forward or backward.
+  wchar_t buffer[] = {L'z', L'a', L'b', L'c', L'z'};
+
+  wchar_t *dst = buffer + 1;
+  wchar_t *ret = LIBC_NAMESPACE::wmemmove(dst, buffer + 2, 2);
+  EXPECT_EQ(ret, dst);
+
+  const wchar_t expected[] = {L'z', L'b', L'c', L'c', L'z'};
+  EXPECT_TRUE(buffer[0] == expected[0]);
+  EXPECT_TRUE(buffer[1] == expected[1]);
+  EXPECT_TRUE(buffer[2] == expected[2]);
+  EXPECT_TRUE(buffer[3] == expected[3]);
+  EXPECT_TRUE(buffer[4] == expected[4]);
+}
+
+TEST(LlvmLibcWMemmoveTest, DstStartsAfterSrc) {
+  wchar_t buffer[] = {L'z', L'a', L'b', L'c', L'z'};
+
+  wchar_t *dst = buffer + 2;
+  wchar_t *ret = LIBC_NAMESPACE::wmemmove(dst, buffer + 1, 2);
+  EXPECT_EQ(ret, dst);
+
+  const wchar_t expected[] = {L'z', L'a', L'a', L'b', L'z'};
+  EXPECT_TRUE(buffer[0] == expected[0]);
+  EXPECT_TRUE(buffer[1] == expected[1]);
+  EXPECT_TRUE(buffer[2] == expected[2]);
+  EXPECT_TRUE(buffer[3] == expected[3]);
+  EXPECT_TRUE(buffer[4] == expected[4]);
+}
+
+// e.g. `Dst` follow `src`.
+// str: [abcdefghij]
+//      [__src_____]
+//      [_____Dst__]
+TEST(LlvmLibcWMemmoveTest, SrcFollowDst) {
+  wchar_t buffer[] = {L'z', L'a', L'b', L'z'};
+
+  wchar_t *dst = buffer + 1;
+  wchar_t *ret = LIBC_NAMESPACE::wmemmove(dst, buffer + 2, 1);
+  EXPECT_EQ(ret, dst);
+
+  const char expected[] = {L'z', L'b', L'b', L'z'};
+  EXPECT_TRUE(buffer[0] == expected[0]);
+  EXPECT_TRUE(buffer[1] == expected[1]);
+  EXPECT_TRUE(buffer[2] == expected[2]);
+  EXPECT_TRUE(buffer[3] == expected[3]);
+}
+
+TEST(LlvmLibcWMemmoveTest, DstFollowSrc) {
+  wchar_t buffer[] = {L'z', L'a', L'b', L'z'};
+
+  wchar_t *dst = buffer + 2;
+  wchar_t *ret = LIBC_NAMESPACE::wmemmove(dst, buffer + 1, 1);
+  EXPECT_EQ(ret, dst);
+
+  const char expected[] = {L'z', L'a', L'a', L'z'};
+  EXPECT_TRUE(buffer[0] == expected[0]);
+  EXPECT_TRUE(buffer[1] == expected[1]);
+  EXPECT_TRUE(buffer[2] == expected[2]);
+  EXPECT_TRUE(buffer[3] == expected[3]);
+}
+
+#if defined(LIBC_ADD_NULL_CHECKS) && !defined(LIBC_HAS_SANITIZER)
+TEST(LlvmLibcWMemmoveTest, NullptrCrash) {
+  wchar_t buffer[] = {L'a', L'b'};
+  // Passing in a nullptr should crash the program.
+  EXPECT_DEATH([&buffer] { LIBC_NAMESPACE::wmemmove(buffer, nullptr, 2); },
+               WITH_SIGNAL(-1));
+  EXPECT_DEATH([&buffer] { LIBC_NAMESPACE::wmemmove(nullptr, buffer, 2); },
+               WITH_SIGNAL(-1));
+}
+#endif // LIBC_HAS_ADDRESS_SANITIZER


        


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