[libc-commits] [libc] [libc] Implement `search/lsearch` (PR #131431)
via libc-commits
libc-commits at lists.llvm.org
Fri Mar 14 22:46:45 PDT 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-libc
Author: Connector Switch (c8ef)
<details>
<summary>Changes</summary>
ref:
- https://man7.org/linux/man-pages/man3/lsearch.3.html
- https://pubs.opengroup.org/onlinepubs/009696699/functions/lsearch.html
---
Full diff: https://github.com/llvm/llvm-project/pull/131431.diff
9 Files Affected:
- (modified) libc/config/linux/aarch64/entrypoints.txt (+1)
- (modified) libc/config/linux/x86_64/entrypoints.txt (+1)
- (modified) libc/include/search.yaml (+10)
- (modified) libc/src/search/CMakeLists.txt (+13)
- (modified) libc/src/search/lfind.cpp (+1-1)
- (added) libc/src/search/lsearch.cpp (+39)
- (added) libc/src/search/lsearch.h (+20)
- (modified) libc/test/src/search/CMakeLists.txt (+10)
- (added) libc/test/src/search/lsearch_test.cpp (+48)
``````````diff
diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index ab1917259519b..c1e688ea7e86b 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -999,6 +999,7 @@ if(LLVM_LIBC_FULL_BUILD)
libc.src.search.hsearch_r
libc.src.search.insque
libc.src.search.lfind
+ libc.src.search.lsearch
libc.src.search.remque
# threads.h entrypoints
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index a29478898fe70..3cb9ee82752b3 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -1113,6 +1113,7 @@ if(LLVM_LIBC_FULL_BUILD)
libc.src.search.hsearch_r
libc.src.search.insque
libc.src.search.lfind
+ libc.src.search.lsearch
libc.src.search.remque
# threads.h entrypoints
diff --git a/libc/include/search.yaml b/libc/include/search.yaml
index b7ce06d48e704..f6f5d6cb062e5 100644
--- a/libc/include/search.yaml
+++ b/libc/include/search.yaml
@@ -69,3 +69,13 @@ functions:
- type: size_t *
- type: size_t
- type: __lsearchcompare_t
+ - name: lsearch
+ standards:
+ - POSIX
+ return_type: void *
+ arguments:
+ - type: const void *
+ - type: void *
+ - type: size_t *
+ - type: size_t
+ - type: __lsearchcompare_t
diff --git a/libc/src/search/CMakeLists.txt b/libc/src/search/CMakeLists.txt
index 497657f40f2f0..d78ea062342a1 100644
--- a/libc/src/search/CMakeLists.txt
+++ b/libc/src/search/CMakeLists.txt
@@ -110,3 +110,16 @@ add_entrypoint_object(
libc.src.__support.CPP.cstddef
libc.src.__support.memory_size
)
+
+add_entrypoint_object(
+ lsearch
+ SRCS
+ lsearch.cpp
+ HDRS
+ lsearch.h
+ DEPENDS
+ libc.include.search
+ libc.src.__support.CPP.cstddef
+ libc.src.__support.memory_size
+ libc.src.string.memory_utils.inline_memcpy
+)
diff --git a/libc/src/search/lfind.cpp b/libc/src/search/lfind.cpp
index c8bf07de0b903..b10065aef2a93 100644
--- a/libc/src/search/lfind.cpp
+++ b/libc/src/search/lfind.cpp
@@ -1,4 +1,4 @@
-//===-- Implementation of lfind -------------------------------*- C++ -*-===//
+//===-- Implementation of lfind ---------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
diff --git a/libc/src/search/lsearch.cpp b/libc/src/search/lsearch.cpp
new file mode 100644
index 0000000000000..e28dc3488413d
--- /dev/null
+++ b/libc/src/search/lsearch.cpp
@@ -0,0 +1,39 @@
+//===-- Implementation of lsearch -------------------------------*- C++ -*-===//
+//
+// 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/search/lsearch.h"
+#include "src/__support/CPP/cstddef.h" // cpp::byte
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+#include "src/__support/memory_size.h"
+#include "src/string/memory_utils/inline_memcpy.h"
+
+namespace LIBC_NAMESPACE_DECL {
+LLVM_LIBC_FUNCTION(void *, lsearch,
+ (const void *key, void *base, size_t *nmemb, size_t size,
+ int (*compar)(const void *, const void *))) {
+ if (key == nullptr || base == nullptr || nmemb == nullptr ||
+ compar == nullptr)
+ return nullptr;
+
+ size_t byte_len = 0;
+ if (internal::mul_overflow(*nmemb, size, &byte_len))
+ return nullptr;
+
+ const cpp::byte *next = reinterpret_cast<const cpp::byte *>(base);
+ const cpp::byte *end = next + byte_len;
+ for (; next < end; next += size)
+ if (compar(key, next) == 0)
+ return const_cast<cpp::byte *>(next);
+
+ *nmemb += 1;
+ inline_memcpy(const_cast<cpp::byte *>(end), key, size);
+ return const_cast<cpp::byte *>(end);
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/search/lsearch.h b/libc/src/search/lsearch.h
new file mode 100644
index 0000000000000..c95e01d396cd0
--- /dev/null
+++ b/libc/src/search/lsearch.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for lsearch -----------------------*- C++ -*-===//
+//
+// 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_SEARCH_LSEARCH_H
+#define LLVM_LIBC_SRC_SEARCH_LSEARCH_H
+
+#include "src/__support/macros/config.h"
+#include <stddef.h> // size_t
+
+namespace LIBC_NAMESPACE_DECL {
+void *lsearch(const void *key, void *base, size_t *nmemb, size_t size,
+ int (*compar)(const void *, const void *));
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_SEARCH_LSEARCH_H
diff --git a/libc/test/src/search/CMakeLists.txt b/libc/test/src/search/CMakeLists.txt
index a1f9aac2094c9..9f34d4d3fd259 100644
--- a/libc/test/src/search/CMakeLists.txt
+++ b/libc/test/src/search/CMakeLists.txt
@@ -35,3 +35,13 @@ add_libc_unittest(
DEPENDS
libc.src.search.lfind
)
+
+add_libc_unittest(
+ lsearch_test
+ SUITE
+ libc_search_unittests
+ SRCS
+ lsearch_test.cpp
+ DEPENDS
+ libc.src.search.lsearch
+)
diff --git a/libc/test/src/search/lsearch_test.cpp b/libc/test/src/search/lsearch_test.cpp
new file mode 100644
index 0000000000000..22ac37f18b7bd
--- /dev/null
+++ b/libc/test/src/search/lsearch_test.cpp
@@ -0,0 +1,48 @@
+//===-- Unittests for lsearch ---------------------------------------------===//
+//
+// 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/search/lsearch.h"
+#include "test/UnitTest/Test.h"
+
+int compar(const void *a, const void *b) {
+ return *reinterpret_cast<const int *>(a) != *reinterpret_cast<const int *>(b);
+}
+
+TEST(LlvmLibcLsearchTest, SearchHead) {
+ int list[3] = {1, 2, 3};
+ size_t len = 3;
+ int key = 1;
+ void *ret = LIBC_NAMESPACE::lsearch(&key, list, &len, sizeof(int), compar);
+ ASSERT_TRUE(ret == &list[0]);
+}
+
+TEST(LlvmLibcLsearchTest, SearchMiddle) {
+ int list[3] = {1, 2, 3};
+ size_t len = 3;
+ int key = 2;
+ void *ret = LIBC_NAMESPACE::lsearch(&key, list, &len, sizeof(int), compar);
+ ASSERT_TRUE(ret == &list[1]);
+}
+
+TEST(LlvmLibcLsearchTest, SearchTail) {
+ int list[3] = {1, 2, 3};
+ size_t len = 3;
+ int key = 3;
+ void *ret = LIBC_NAMESPACE::lsearch(&key, list, &len, sizeof(int), compar);
+ ASSERT_TRUE(ret == &list[2]);
+}
+
+TEST(LlvmLibcLsearchTest, SearchNonExistent) {
+ int list[4] = {1, 2, 3, 0};
+ size_t len = 3;
+ int key = 4;
+ void *ret = LIBC_NAMESPACE::lsearch(&key, list, &len, sizeof(int), compar);
+ ASSERT_TRUE(ret == &list[3]);
+ ASSERT_EQ(key, list[3]);
+ ASSERT_EQ(len, 4UL);
+}
``````````
</details>
https://github.com/llvm/llvm-project/pull/131431
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