[libc-commits] [libc] [llvm] [libc] wcslcpy implementation (PR #146571)
via libc-commits
libc-commits at lists.llvm.org
Tue Jul 1 09:54:43 PDT 2025
https://github.com/sribee8 updated https://github.com/llvm/llvm-project/pull/146571
>From bcfa14087391f7e414b9f34bef4f16c146e47020 Mon Sep 17 00:00:00 2001
From: Sriya Pratipati <sriyap at google.com>
Date: Tue, 1 Jul 2025 16:48:22 +0000
Subject: [PATCH 1/2] [libc] wcslcpy implementation
Implemented wcslcpy and tests.
---
libc/config/linux/x86_64/entrypoints.txt | 1 +
libc/include/wchar.yaml | 8 ++++
libc/src/wchar/CMakeLists.txt | 11 +++++
libc/src/wchar/wcslcpy.cpp | 32 +++++++++++++++
libc/src/wchar/wcslcpy.h | 23 +++++++++++
libc/test/src/wchar/CMakeLists.txt | 11 +++++
libc/test/src/wchar/wcslcpy_test.cpp | 51 ++++++++++++++++++++++++
7 files changed, 137 insertions(+)
create mode 100644 libc/src/wchar/wcslcpy.cpp
create mode 100644 libc/src/wchar/wcslcpy.h
create mode 100644 libc/test/src/wchar/wcslcpy_test.cpp
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index 59c248871f83a..8035b964d1a5d 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -385,6 +385,7 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.wchar.wcsstr
libc.src.wchar.wcsncat
libc.src.wchar.wcscpy
+ libc.src.wchar.wcslcpy
libc.src.wchar.wmemchr
libc.src.wchar.wcpcpy
libc.src.wchar.wcpncpy
diff --git a/libc/include/wchar.yaml b/libc/include/wchar.yaml
index 02e1ba331b7cc..7d17d84d16c11 100644
--- a/libc/include/wchar.yaml
+++ b/libc/include/wchar.yaml
@@ -203,6 +203,14 @@ functions:
arguments:
- type: wchar_t *__restrict
- type: const wchar_t *__restrict
+ - name: wcslcpy
+ standards:
+ - stdc
+ return_type: size_t
+ arguments:
+ - type: wchar_t *__restrict
+ - type: const wchar_t *__restrict
+ - type: size_t
- name: wcstok
standards:
- stdc
diff --git a/libc/src/wchar/CMakeLists.txt b/libc/src/wchar/CMakeLists.txt
index f2f4b1d38f0f3..2dc14db998766 100644
--- a/libc/src/wchar/CMakeLists.txt
+++ b/libc/src/wchar/CMakeLists.txt
@@ -340,3 +340,14 @@ add_entrypoint_object(
libc.hdr.wchar_macros
libc.src.string.string_utils
)
+
+add_entrypoint_object(
+ wcslcpy
+ SRCS
+ wcslcpy.cpp
+ HDRS
+ wcslcpy.h
+ DEPENDS
+ libc.hdr.types.size_t
+ libc.hdr.wchar_macros
+)
diff --git a/libc/src/wchar/wcslcpy.cpp b/libc/src/wchar/wcslcpy.cpp
new file mode 100644
index 0000000000000..7239334a07f77
--- /dev/null
+++ b/libc/src/wchar/wcslcpy.cpp
@@ -0,0 +1,32 @@
+//===-- Implementation of wcslcpy -----------------------------------------===//
+//
+// 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/wcslcpy.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(size_t, wcslcpy,
+ (wchar_t *__restrict dst, const wchar_t *__restrict src,
+ size_t dstsize)) {
+ size_t len = internal::string_length(src);
+ if (dstsize == 0)
+ return len;
+ size_t i = 0;
+ for (; i < dstsize - 1 && src[i] != L'\0'; ++i)
+ dst[i] = src[i];
+ dst[i] = L'\0';
+ return len;
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/wchar/wcslcpy.h b/libc/src/wchar/wcslcpy.h
new file mode 100644
index 0000000000000..97b02f616605d
--- /dev/null
+++ b/libc/src/wchar/wcslcpy.h
@@ -0,0 +1,23 @@
+//===-- Implementation header for wcslcpy ---------------------------------===//
+//
+// 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_WCSLCPY_H
+#define LLVM_LIBC_SRC_WCHAR_WCSLCPY_H
+
+#include "hdr/types/size_t.h"
+#include "hdr/types/wchar_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+size_t wcslcpy(wchar_t *__restrict dst, const wchar_t *__restrict src,
+ size_t dstsize);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_WCHAR_WCSLCPY_H
diff --git a/libc/test/src/wchar/CMakeLists.txt b/libc/test/src/wchar/CMakeLists.txt
index 657343d072158..aea520feee504 100644
--- a/libc/test/src/wchar/CMakeLists.txt
+++ b/libc/test/src/wchar/CMakeLists.txt
@@ -303,6 +303,17 @@ add_libc_test(
libc.src.wchar.wcpcpy
)
+add_libc_test(
+ wcslcpy_test
+ SUITE
+ libc_wchar_unittests
+ SRCS
+ wcslcpy_test.cpp
+ DEPENDS
+ libc.hdr.types.size_t
+ libc.src.wchar.wcslcpy
+)
+
add_libc_test(
wcpncpy_test
SUITE
diff --git a/libc/test/src/wchar/wcslcpy_test.cpp b/libc/test/src/wchar/wcslcpy_test.cpp
new file mode 100644
index 0000000000000..9b14a62293f63
--- /dev/null
+++ b/libc/test/src/wchar/wcslcpy_test.cpp
@@ -0,0 +1,51 @@
+//===-- Unittests for wcslcpy ---------------------------------------------===//
+//
+// 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/wcslcpy.h"
+#include "test/UnitTest/Test.h"
+
+TEST(LlvmLibcWCSLCpyTest, BiggerSource) {
+ const wchar_t *src = L"abcde";
+ wchar_t dst[3];
+ size_t res = LIBC_NAMESPACE::wcslcpy(dst, src, 3);
+ ASSERT_TRUE(dst[0] == L'a');
+ ASSERT_TRUE(dst[1] == L'b');
+ // Should append null terminator
+ ASSERT_TRUE(dst[2] == L'\0');
+ // Should still return length of src
+ ASSERT_EQ(res, size_t(5));
+}
+
+TEST(LlvmLibcWCSLCpyTest, CopyZero) {
+ const wchar_t *src = L"abcde";
+ wchar_t dst = L'f';
+ // Copying zero should not change destination
+ size_t res = LIBC_NAMESPACE::wcslcpy(&dst, src, 0);
+ ASSERT_TRUE(dst == L'f');
+ // Should still return length of src
+ ASSERT_EQ(res, size_t(5));
+}
+
+TEST(LlvmLibcWCSLCpyTest, SmallerSource) {
+ const wchar_t *src = L"abc";
+ wchar_t dst[7]{L"111111"};
+ size_t res = LIBC_NAMESPACE::wcslcpy(dst, src, 7);
+ ASSERT_TRUE(dst[0] == L'a');
+ ASSERT_TRUE(dst[1] == L'b');
+ ASSERT_TRUE(dst[2] == L'c');
+ // Should append null terminator after copying source
+ ASSERT_TRUE(dst[3] == L'\0');
+ // Should not change following characters
+ ASSERT_TRUE(dst[4] == L'1');
+ ASSERT_TRUE(dst[5] == L'1');
+ ASSERT_TRUE(dst[6] == L'\0');
+ // Should still return length of src
+ ASSERT_EQ(res, size_t(3));
+}
>From ca511e789ed35525699ed61276ea2e664a1e242d Mon Sep 17 00:00:00 2001
From: Sriya Pratipati <sriyap at google.com>
Date: Tue, 1 Jul 2025 16:54:28 +0000
Subject: [PATCH 2/2] added to bazel files
---
utils/bazel/llvm-project-overlay/libc/BUILD.bazel | 13 +++++++++++++
.../libc/test/src/wchar/BUILD.bazel | 10 ++++++++++
2 files changed, 23 insertions(+)
diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
index 2484a2f1e2bd7..b073ba9a2e4e1 100644
--- a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@@ -5827,6 +5827,19 @@ libc_function(
],
)
+libc_function(
+ name = "wcslcpy",
+ srcs = ["src/wchar/wcslcpy.cpp"],
+ hdrs = ["src/wchar/wcslcpy.h"],
+ deps = [
+ ":__support_common",
+ ":__support_macros_config",
+ ":string_utils",
+ ":types_size_t",
+ ":types_wchar_t",
+ ],
+)
+
libc_function(
name = "wcslen",
srcs = ["src/wchar/wcslen.cpp"],
diff --git a/utils/bazel/llvm-project-overlay/libc/test/src/wchar/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/test/src/wchar/BUILD.bazel
index f94065237ef4f..431a7ecb8bfe8 100644
--- a/utils/bazel/llvm-project-overlay/libc/test/src/wchar/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/test/src/wchar/BUILD.bazel
@@ -83,6 +83,16 @@ libc_test(
],
)
+libc_test(
+ name = "wcslcpy_test",
+ srcs = ["wcslcpy_test.cpp"],
+ deps = [
+ "//libc:types_size_t",
+ "//libc:types_wchar_t",
+ "//libc:wcslcpy",
+ ],
+)
+
libc_test(
name = "wcslen_test",
srcs = ["wcslen_test.cpp"],
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