[libc] [llvm] [libc] wcslcat implementation (PR #146588)
via llvm-commits
llvm-commits at lists.llvm.org
Tue Jul 1 11:29:03 PDT 2025
https://github.com/sribee8 updated https://github.com/llvm/llvm-project/pull/146588
>From e151ed9c707b4fb550b026f5cdba1446fd9022a2 Mon Sep 17 00:00:00 2001
From: Sriya Pratipati <sriyap at google.com>
Date: Tue, 1 Jul 2025 18:26:02 +0000
Subject: [PATCH 1/2] [libc] wcslcat implementation
implemented wcslcat and tests.
---
libc/config/linux/x86_64/entrypoints.txt | 1 +
libc/include/wchar.yaml | 8 +++
libc/src/wchar/CMakeLists.txt | 12 ++++
libc/src/wchar/wcslcat.cpp | 39 +++++++++++++
libc/src/wchar/wcslcat.h | 23 ++++++++
libc/test/src/wchar/CMakeLists.txt | 11 ++++
libc/test/src/wchar/wcslcat_test.cpp | 72 ++++++++++++++++++++++++
7 files changed, 166 insertions(+)
create mode 100644 libc/src/wchar/wcslcat.cpp
create mode 100644 libc/src/wchar/wcslcat.h
create mode 100644 libc/test/src/wchar/wcslcat_test.cpp
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index 59c248871f83a..1aa07f3750ca9 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -384,6 +384,7 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.wchar.wcscat
libc.src.wchar.wcsstr
libc.src.wchar.wcsncat
+ libc.src.wchar.wcslcat
libc.src.wchar.wcscpy
libc.src.wchar.wmemchr
libc.src.wchar.wcpcpy
diff --git a/libc/include/wchar.yaml b/libc/include/wchar.yaml
index 02e1ba331b7cc..0cf72ea923344 100644
--- a/libc/include/wchar.yaml
+++ b/libc/include/wchar.yaml
@@ -166,6 +166,14 @@ functions:
arguments:
- type: wchar_t *__restrict
- type: const wchar_t *__restrict
+ - name: wcslcat
+ standards:
+ - stdc
+ return_type: size_t
+ arguments:
+ - type: wchar_t *__restrict
+ - type: const wchar_t *__restrict
+ - type: size_t
- name: wcsstr
standards:
- stdc
diff --git a/libc/src/wchar/CMakeLists.txt b/libc/src/wchar/CMakeLists.txt
index f2f4b1d38f0f3..40d94576ac9e1 100644
--- a/libc/src/wchar/CMakeLists.txt
+++ b/libc/src/wchar/CMakeLists.txt
@@ -307,6 +307,18 @@ add_entrypoint_object(
libc.src.string.string_utils
)
+add_entrypoint_object(
+ wcslcat
+ SRCS
+ wcslcat.cpp
+ HDRS
+ wcslcat.h
+ DEPENDS
+ libc.hdr.types.size_t
+ libc.hdr.wchar_macros
+ libc.src.string.string_utils
+)
+
add_entrypoint_object(
wmemchr
SRCS
diff --git a/libc/src/wchar/wcslcat.cpp b/libc/src/wchar/wcslcat.cpp
new file mode 100644
index 0000000000000..eff3974f8dff8
--- /dev/null
+++ b/libc/src/wchar/wcslcat.cpp
@@ -0,0 +1,39 @@
+//===-- Implementation of wcslcat -----------------------------------------===//
+//
+// 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/wcslcat.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, wcslcat,
+ (wchar_t *__restrict dst, const wchar_t *__restrict src,
+ size_t dstsize)) {
+ size_t dstlen = internal::string_length(dst);
+ size_t srclen = internal::string_length(src);
+ size_t limit = dstsize - dstlen - 1;
+
+ if (static_cast<int>(limit) < 0)
+ return (dstsize < dstlen ? dstsize : dstlen) + srclen;
+ size_t i = 0;
+ for (; i < limit && src[i] != L'\0'; ++i) {
+ dst[dstlen + i] = src[i];
+ }
+
+ // appending null terminator if there is room
+ if (dstlen + i < dstlen + dstsize)
+ dst[dstlen + i] = L'\0';
+ return (dstsize < dstlen ? dstsize : dstlen) + srclen;
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/wchar/wcslcat.h b/libc/src/wchar/wcslcat.h
new file mode 100644
index 0000000000000..fd964e1af49d5
--- /dev/null
+++ b/libc/src/wchar/wcslcat.h
@@ -0,0 +1,23 @@
+//===-- Implementation header for wcslcat ---------------------------------===//
+//
+// 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_WCSLCAT_H
+#define LLVM_LIBC_SRC_WCHAR_WCSLCAT_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 wcslcat(wchar_t *__restrict dst, const wchar_t *__restrict src,
+ size_t dstsize);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_WCHAR_WCSLCAT_H
diff --git a/libc/test/src/wchar/CMakeLists.txt b/libc/test/src/wchar/CMakeLists.txt
index 657343d072158..baae1e822e854 100644
--- a/libc/test/src/wchar/CMakeLists.txt
+++ b/libc/test/src/wchar/CMakeLists.txt
@@ -283,6 +283,17 @@ add_libc_test(
libc.src.wchar.wcsncat
)
+add_libc_test(
+ wcslcat_test
+ SUITE
+ libc_wchar_unittests
+ SRCS
+ wcslcat_test.cpp
+ DEPENDS
+ libc.src.wchar.wcslcat
+ libc.hdr.types.size_t
+)
+
add_libc_test(
wcscpy_test
SUITE
diff --git a/libc/test/src/wchar/wcslcat_test.cpp b/libc/test/src/wchar/wcslcat_test.cpp
new file mode 100644
index 0000000000000..34b5af7767346
--- /dev/null
+++ b/libc/test/src/wchar/wcslcat_test.cpp
@@ -0,0 +1,72 @@
+//===-- Unittests for wcslcat ---------------------------------------------===//
+//
+// 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/wcslcat.h"
+#include "test/UnitTest/Test.h"
+
+TEST(LlvmLibcWCSLCatTest, TooBig) {
+ const wchar_t *src = L"cd";
+ wchar_t dst[4]{L"ab"};
+ size_t res = LIBC_NAMESPACE::wcslcat(dst, src, 3);
+ ASSERT_TRUE(dst[0] == L'a');
+ ASSERT_TRUE(dst[1] == L'b');
+ ASSERT_TRUE(dst[2] == L'\0');
+ // Should still return src length + dst length
+ ASSERT_EQ(res, size_t(4));
+ // Not enough space to copy d
+ res = LIBC_NAMESPACE::wcslcat(dst, src, 4);
+ ASSERT_TRUE(dst[0] == L'a');
+ ASSERT_TRUE(dst[1] == L'b');
+ ASSERT_TRUE(dst[2] == L'c');
+ ASSERT_TRUE(dst[3] == L'\0');
+ ASSERT_EQ(res, size_t(4));
+}
+
+TEST(LlvmLibcWCSLCatTest, Smaller) {
+ const wchar_t *src = L"cd";
+ wchar_t dst[7]{L"ab"};
+ size_t res = LIBC_NAMESPACE::wcslcat(dst, src, 7);
+ ASSERT_TRUE(dst[0] == L'a');
+ ASSERT_TRUE(dst[1] == L'b');
+ ASSERT_TRUE(dst[2] == L'c');
+ ASSERT_TRUE(dst[3] == L'd');
+ ASSERT_TRUE(dst[4] == L'\0');
+ ASSERT_EQ(res, size_t(4));
+}
+
+TEST(LlvmLibcWCSLCatTest, SmallerNoOverwriteAfter0) {
+ const wchar_t *src = L"cd";
+ wchar_t dst[8]{L"ab\0\0efg"};
+ size_t res = LIBC_NAMESPACE::wcslcat(dst, src, 8);
+ ASSERT_TRUE(dst[0] == L'a');
+ ASSERT_TRUE(dst[1] == L'b');
+ ASSERT_TRUE(dst[2] == L'c');
+ ASSERT_TRUE(dst[3] == L'd');
+ ASSERT_TRUE(dst[4] == L'\0');
+ ASSERT_TRUE(dst[5] == L'f');
+ ASSERT_TRUE(dst[6] == L'g');
+ ASSERT_TRUE(dst[7] == L'\0');
+ ASSERT_EQ(res, size_t(4));
+}
+
+TEST(LlvmLibcWCSLCatTest, No0) {
+ const wchar_t *src = L"cd";
+ wchar_t dst[7]{L"ab"};
+ size_t res = LIBC_NAMESPACE::wcslcat(dst, src, 1);
+ ASSERT_TRUE(dst[0] == L'a');
+ ASSERT_TRUE(dst[1] == L'b');
+ ASSERT_TRUE(dst[2] == L'\0');
+ ASSERT_EQ(res, size_t(3));
+ res = LIBC_NAMESPACE::wcslcat(dst, src, 2);
+ ASSERT_TRUE(dst[0] == L'a');
+ ASSERT_TRUE(dst[1] == L'b');
+ ASSERT_TRUE(dst[2] == L'\0');
+ ASSERT_EQ(res, size_t(4));
+}
>From 7f69a1e4639c4eadd25277e81a35f3ba3e83f978 Mon Sep 17 00:00:00 2001
From: Sriya Pratipati <sriyap at google.com>
Date: Tue, 1 Jul 2025 18:28:47 +0000
Subject: [PATCH 2/2] added wcslcat to bazel files
---
utils/bazel/llvm-project-overlay/libc/BUILD.bazel | 13 +++++++++++++
.../libc/test/src/wchar/BUILD.bazel | 11 +++++++++++
2 files changed, 24 insertions(+)
diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
index 2484a2f1e2bd7..6dadb0b6a78ca 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 = "wcslcat",
+ srcs = ["src/wchar/wcslcat.cpp"],
+ hdrs = ["src/wchar/wcslcat.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..fb2ffa3f8ebb6 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 +83,17 @@ libc_test(
],
)
+
+libc_test(
+ name = "wcslcat_test",
+ srcs = ["wcslcat_test.cpp"],
+ deps = [
+ "//libc:types_size_t",
+ "//libc:types_wchar_t",
+ "//libc:wcslcat",
+ ],
+)
+
libc_test(
name = "wcslen_test",
srcs = ["wcslen_test.cpp"],
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