[libc] add strndup
add an implementation of strndup
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D112846
GitOrigin-RevId: 3bbbec1ae7b7b3c3dc4e6a1801fb5bdb930aad79
diff --git a/config/linux/x86_64/entrypoints.txt b/config/linux/x86_64/entrypoints.txt
index 9f25e9e..bce6cbf 100644
--- a/config/linux/x86_64/entrypoints.txt
+++ b/config/linux/x86_64/entrypoints.txt
@@ -239,6 +239,7 @@
# string.h entrypoints that depend on malloc
libc.src.string.strdup
+ libc.src.string.strndup
)
endif()
diff --git a/spec/stdc.td b/spec/stdc.td
index c997d43..2218bfc 100644
--- a/spec/stdc.td
+++ b/spec/stdc.td
@@ -285,6 +285,11 @@
[ArgSpec<ConstCharPtr>]
>,
FunctionSpec<
+ "strndup",
+ RetValSpec<CharPtr>,
+ [ArgSpec<ConstCharPtr>,ArgSpec<SizeTType>]
+ >,
+ FunctionSpec<
"strpbrk",
RetValSpec<CharPtr>,
[ArgSpec<ConstCharPtr>, ArgSpec<ConstCharPtr>]
diff --git a/src/string/CMakeLists.txt b/src/string/CMakeLists.txt
index 923ba09..0fb50b6 100644
--- a/src/string/CMakeLists.txt
+++ b/src/string/CMakeLists.txt
@@ -154,6 +154,18 @@
)
add_entrypoint_object(
+ strndup
+ SRCS
+ strndup.cpp
+ HDRS
+ strndup.h
+ DEPENDS
+ .memcpy
+ .string_utils
+ libc.include.stdlib
+)
+
+add_entrypoint_object(
strnlen
SRCS
strnlen.cpp
diff --git a/src/string/strndup.cpp b/src/string/strndup.cpp
new file mode 100644
index 0000000..6c904f4
--- /dev/null
+++ b/src/string/strndup.cpp
@@ -0,0 +1,35 @@
+//===-- Implementation of strndup -----------------------------------------===//
+//
+// 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/string/strndup.h"
+#include "src/string/memcpy.h"
+#include "src/string/string_utils.h"
+
+#include "src/__support/common.h"
+
+#include <stddef.h>
+#include <stdlib.h>
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(char *, strndup, (const char *src, size_t size)) {
+ if (src == nullptr)
+ return nullptr;
+ size_t len = internal::string_length(src);
+ if (len > size)
+ len = size;
+ char *dest = reinterpret_cast<char *>(::malloc(len + 1)); // NOLINT
+ if (dest == nullptr)
+ return nullptr;
+ char *result =
+ reinterpret_cast<char *>(__llvm_libc::memcpy(dest, src, len + 1));
+ result[len] = '\0';
+ return result;
+}
+
+} // namespace __llvm_libc
diff --git a/src/string/strndup.h b/src/string/strndup.h
new file mode 100644
index 0000000..0a593a7
--- /dev/null
+++ b/src/string/strndup.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for strndup -----------------------*- 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_STRING_STRNDUP_H
+#define LLVM_LIBC_SRC_STRING_STRNDUP_H
+
+#include <string.h>
+
+namespace __llvm_libc {
+
+char *strndup(const char *src, size_t size);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_STRING_STRNDUP_H
diff --git a/test/src/string/CMakeLists.txt b/test/src/string/CMakeLists.txt
index 8154aaa..a5b931d 100644
--- a/test/src/string/CMakeLists.txt
+++ b/test/src/string/CMakeLists.txt
@@ -144,6 +144,17 @@
)
add_libc_unittest(
+ strndup_test
+ SUITE
+ libc_string_unittests
+ SRCS
+ strndup_test.cpp
+ DEPENDS
+ libc.include.stdlib
+ libc.src.string.strndup
+)
+
+add_libc_unittest(
strnlen_test
SUITE
libc_string_unittests
diff --git a/test/src/string/strndup_test.cpp b/test/src/string/strndup_test.cpp
new file mode 100644
index 0000000..0a17a72
--- /dev/null
+++ b/test/src/string/strndup_test.cpp
@@ -0,0 +1,52 @@
+//===-- Unittests for strndup ---------------------------------------------===//
+//
+// 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/string/strndup.h"
+#include "utils/UnitTest/Test.h"
+#include <stdlib.h>
+
+TEST(LlvmLibcstrndupTest, EmptyString) {
+ const char *empty = "";
+
+ char *result = __llvm_libc::strndup(empty, 1);
+ ASSERT_NE(result, static_cast<char *>(nullptr));
+ ASSERT_NE(empty, const_cast<const char *>(result));
+ ASSERT_STREQ(empty, result);
+ ::free(result);
+}
+
+TEST(LlvmLibcstrndupTest, AnyString) {
+ const char *abc = "abc";
+
+ char *result = __llvm_libc::strndup(abc, 3);
+
+ ASSERT_NE(result, static_cast<char *>(nullptr));
+ ASSERT_NE(abc, const_cast<const char *>(result));
+ ASSERT_STREQ(abc, result);
+ ::free(result);
+
+ result = __llvm_libc::strndup(abc, 1);
+
+ ASSERT_NE(result, static_cast<char *>(nullptr));
+ ASSERT_NE(abc, const_cast<const char *>(result));
+ ASSERT_STREQ("a", result);
+ ::free(result);
+
+ result = __llvm_libc::strndup(abc, 10);
+
+ ASSERT_NE(result, static_cast<char *>(nullptr));
+ ASSERT_NE(abc, const_cast<const char *>(result));
+ ASSERT_STREQ(abc, result);
+ ::free(result);
+}
+
+TEST(LlvmLibcstrndupTest, NullPtr) {
+ char *result = __llvm_libc::strndup(nullptr, 0);
+
+ ASSERT_EQ(result, static_cast<char *>(nullptr));
+}
