[libc-commits] [libc] cfba771 - WCSChr Implementation (#141690)

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Wed May 28 14:08:06 PDT 2025


Author: sribee8
Date: 2025-05-28T14:08:03-07:00
New Revision: cfba7718d28788891860915a2232021fc227cf91

URL: https://github.com/llvm/llvm-project/commit/cfba7718d28788891860915a2232021fc227cf91
DIFF: https://github.com/llvm/llvm-project/commit/cfba7718d28788891860915a2232021fc227cf91.diff

LOG: WCSChr Implementation (#141690)

implemented wcschr and tests

---------

Co-authored-by: Sriya Pratipati <sriyap at google.com>

Added: 
    libc/src/wchar/wcschr.cpp
    libc/src/wchar/wcschr.h
    libc/test/src/wchar/wcschr_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 9f447dd0d35d2..52e746e32a1cd 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -364,6 +364,7 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.wchar.btowc
     libc.src.wchar.wcslen
     libc.src.wchar.wctob
+    libc.src.wchar.wcschr
 
     # sys/uio.h entrypoints
     libc.src.sys.uio.writev

diff  --git a/libc/include/wchar.yaml b/libc/include/wchar.yaml
index 0ac9aa29f0a18..987bdc0b806dc 100644
--- a/libc/include/wchar.yaml
+++ b/libc/include/wchar.yaml
@@ -27,3 +27,10 @@ functions:
     return_type: wint_t
     arguments:
       - type: int
+  - name: wcschr
+    standards:
+      - stdc
+    return_type: const wchar_t *
+    arguments: 
+      - type: const wchar_t *
+      - type: wchar_t

diff  --git a/libc/src/wchar/CMakeLists.txt b/libc/src/wchar/CMakeLists.txt
index 703db75b5b194..41034cab16d4d 100644
--- a/libc/src/wchar/CMakeLists.txt
+++ b/libc/src/wchar/CMakeLists.txt
@@ -33,3 +33,14 @@ add_entrypoint_object(
     libc.hdr.wchar_macros
     libc.src.__support.wctype_utils
 )
+
+add_entrypoint_object(
+  wcschr
+  SRCS
+    wcschr.cpp
+  HDRS
+    wcschr.h
+  DEPENDS
+    libc.hdr.wchar_macros
+    libc.src.__support.wctype_utils
+)

diff  --git a/libc/src/wchar/wcschr.cpp b/libc/src/wchar/wcschr.cpp
new file mode 100644
index 0000000000000..defc2ce3c3b72
--- /dev/null
+++ b/libc/src/wchar/wcschr.cpp
@@ -0,0 +1,25 @@
+//===-- Implementation of wcschr ------------------------------------------===//
+//
+// 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/wcschr.h"
+
+#include "hdr/types/wchar_t.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(const wchar_t *, wcschr, (const wchar_t *s, wchar_t c)) {
+  for (; *s && *s != c; ++s)
+    ;
+  if (*s == c)
+    return s;
+  return nullptr;
+}
+
+} // namespace LIBC_NAMESPACE_DECL

diff  --git a/libc/src/wchar/wcschr.h b/libc/src/wchar/wcschr.h
new file mode 100644
index 0000000000000..70bf2839f2e9e
--- /dev/null
+++ b/libc/src/wchar/wcschr.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for wcschr ----------------------------------===//
+//
+// 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_WCSCHR_H
+#define LLVM_LIBC_SRC_WCHAR_WCSCHR_H
+
+#include "hdr/types/wchar_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+const wchar_t *wcschr(const wchar_t *s, wchar_t c);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_WCHAR_WCSCHR_H

diff  --git a/libc/test/src/wchar/CMakeLists.txt b/libc/test/src/wchar/CMakeLists.txt
index d41e328fc9d90..7d64dfeb13b6e 100644
--- a/libc/test/src/wchar/CMakeLists.txt
+++ b/libc/test/src/wchar/CMakeLists.txt
@@ -32,3 +32,13 @@ add_libc_test(
   DEPENDS
     libc.src.wchar.wctob
 )
+
+add_libc_test(
+  wcschr_test
+  SUITE
+    libc_wchar_unittests
+  SRCS
+    wcschr_test.cpp
+  DEPENDS
+    libc.src.wchar.wcschr
+)

diff  --git a/libc/test/src/wchar/wcschr_test.cpp b/libc/test/src/wchar/wcschr_test.cpp
new file mode 100644
index 0000000000000..b494f3d632ec9
--- /dev/null
+++ b/libc/test/src/wchar/wcschr_test.cpp
@@ -0,0 +1,61 @@
+//===-- Unittests for wcschr ----------------------------------------------===//
+//
+// 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/wchar_t.h"
+#include "src/wchar/wcschr.h"
+#include "test/UnitTest/Test.h"
+
+TEST(LlvmLibcWCSChrTest, FindsFirstCharacter) {
+  // Should return pointer to original string since 'a' is the first character.
+  const wchar_t *src = L"abcde";
+  ASSERT_EQ(LIBC_NAMESPACE::wcschr(src, L'a'), src);
+}
+
+TEST(LlvmLibcWCSChrTest, FindsMiddleCharacter) {
+  // Should return pointer to 'c'.
+  const wchar_t *src = L"abcde";
+  ASSERT_EQ(LIBC_NAMESPACE::wcschr(src, L'c'), (src + 2));
+}
+
+TEST(LlvmLibcWCSChrTest, FindsLastCharacterThatIsNotNullTerminator) {
+  // Should return pointer to 'e'.
+  const wchar_t *src = L"abcde";
+  ASSERT_EQ(LIBC_NAMESPACE::wcschr(src, L'e'), (src + 4));
+}
+
+TEST(LlvmLibcWCSChrTest, FindsNullTerminator) {
+  // Should return pointer to null terminator.
+  const wchar_t *src = L"abcde";
+  ASSERT_EQ(LIBC_NAMESPACE::wcschr(src, L'\0'), (src + 5));
+}
+
+TEST(LlvmLibcWCSChrTest, CharacterNotWithinStringShouldReturnNullptr) {
+  // Since 'z' is not within the string, should return nullptr.
+  const wchar_t *src = L"abcde";
+  ASSERT_EQ(LIBC_NAMESPACE::wcschr(src, L'z'), nullptr);
+}
+
+TEST(LlvmLibcWCSChrTest, ShouldFindFirstOfDuplicates) {
+  // Should return pointer to the first '1'.
+  const wchar_t *src = L"abc1def1ghi";
+  ASSERT_EQ((int)(LIBC_NAMESPACE::wcschr(src, L'1') - src), 3);
+
+  // Should return original string since 'X' is the first character.
+  const wchar_t *dups = L"XXXXX";
+  ASSERT_EQ(LIBC_NAMESPACE::wcschr(dups, L'X'), dups);
+}
+
+TEST(LlvmLibcWCSChrTest, EmptyStringShouldOnlyMatchNullTerminator) {
+  // Null terminator should match
+  const wchar_t *src = L"";
+  ASSERT_EQ(src, LIBC_NAMESPACE::wcschr(src, L'\0'));
+  // All other characters should not match
+  ASSERT_EQ(LIBC_NAMESPACE::wcschr(src, L'Z'), nullptr);
+  ASSERT_EQ(LIBC_NAMESPACE::wcschr(src, L'3'), nullptr);
+  ASSERT_EQ(LIBC_NAMESPACE::wcschr(src, L'*'), nullptr);
+}


        


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