[libc-commits] [libc] [libc] Add stub implementation for strptime. (PR #211088)

Alex Strelnikov via libc-commits libc-commits at lists.llvm.org
Tue Jul 21 12:51:07 PDT 2026 

https://github.com/strel-12 updated https://github.com/llvm/llvm-project/pull/211088

>From 165b76e85a9bc53094fa0604506d13d770bf1d26 Mon Sep 17 00:00:00 2001
From: Alex Strelnikov <strel at google.com>
Date: Tue, 21 Jul 2026 19:01:00 +0000
Subject: [PATCH 1/3] Add stub implementation for strptime.

---
 libc/config/linux/aarch64/entrypoints.txt |  3 +++
 libc/config/linux/x86_64/entrypoints.txt  |  3 +++
 libc/include/time.yaml                    |  8 ++++++++
 libc/src/time/CMakeLists.txt              | 11 +++++++++++
 libc/src/time/strptime.cpp                | 23 +++++++++++++++++++++++
 libc/src/time/strptime.h                  | 22 ++++++++++++++++++++++
 libc/test/src/time/CMakeLists.txt         | 11 +++++++++++
 libc/test/src/time/strptime_test.cpp      | 19 +++++++++++++++++++
 8 files changed, 100 insertions(+)
 create mode 100644 libc/src/time/strptime.cpp
 create mode 100644 libc/src/time/strptime.h
 create mode 100644 libc/test/src/time/strptime_test.cpp

diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index 2e7b9276ab068..f8aa96e15077e 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -1333,6 +1333,9 @@ if(LLVM_LIBC_ENABLE_EXPERIMENTAL_ENTRYPOINTS)
       # sys/ptrace.h entrypoints
       libc.src.sys.ptrace.ptrace
 
+      # time.h entrypoints
+      libc.src.time.strptime
+
       # wchar.h entrypoints
       libc.src.wchar.swprintf
     )
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index 0a4fb747c2940..72fb8aa8a292c 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -1570,6 +1570,9 @@ if(LLVM_LIBC_ENABLE_EXPERIMENTAL_ENTRYPOINTS)
       # sys/ptrace.h entrypoints
       libc.src.sys.ptrace.ptrace
 
+      # time.h entrypoints
+      libc.src.time.strptime
+
       # wchar.h entrypoints
       libc.src.wchar.swprintf
     )
diff --git a/libc/include/time.yaml b/libc/include/time.yaml
index bd62379205d1e..2c18c5b8fc87f 100644
--- a/libc/include/time.yaml
+++ b/libc/include/time.yaml
@@ -132,6 +132,14 @@ functions:
       - type: const char *__restrict
       - type: const struct tm *__restrict
       - type: locale_t
+  - name: strptime
+    standards:
+      - stdc
+    return_type: char *
+    arguments:
+      - type: const char *__restrict
+      - type: const char *__restrict
+      - type: struct tm *__restrict
   - name: time
     standards:
       - stdc
diff --git a/libc/src/time/CMakeLists.txt b/libc/src/time/CMakeLists.txt
index 76178542c6c9a..d4ccc0ce4b4f3 100644
--- a/libc/src/time/CMakeLists.txt
+++ b/libc/src/time/CMakeLists.txt
@@ -214,6 +214,17 @@ add_entrypoint_object(
     libc.src.__support.macros.null_check
 )
 
+add_entrypoint_object(
+  strptime
+  SRCS
+    strptime.cpp
+  HDRS
+    strptime.h
+  DEPENDS
+    libc.hdr.types.struct_tm
+    libc.src.__support.macros.config
+)
+
 add_entrypoint_object(
   time
   SRCS
diff --git a/libc/src/time/strptime.cpp b/libc/src/time/strptime.cpp
new file mode 100644
index 0000000000000..e1d099034fc04
--- /dev/null
+++ b/libc/src/time/strptime.cpp
@@ -0,0 +1,23 @@
+//===-- Implementation of strptime function -------------------------------===//
+//
+// 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/time/strptime.h"
+#include "hdr/types/struct_tm.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(char *, strptime,
+                   ([[maybe_unused]] const char *__restrict buf,
+                    [[maybe_unused]] const char *__restrict format,
+                    [[maybe_unused]] const tm *__restrict tm)) {
+  return nullptr;
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/time/strptime.h b/libc/src/time/strptime.h
new file mode 100644
index 0000000000000..15107dcdd64b5
--- /dev/null
+++ b/libc/src/time/strptime.h
@@ -0,0 +1,22 @@
+//===-- Implementation header of strptime -----------------------*- 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_TIME_STRPTIME_H
+#define LLVM_LIBC_SRC_TIME_STRPTIME_H
+
+#include "hdr/types/struct_tm.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+char *strptime(const char *__restrict buf, const char *__restrict format,
+               const tm *__restrict tm);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_TIME_STRPTIME_H
diff --git a/libc/test/src/time/CMakeLists.txt b/libc/test/src/time/CMakeLists.txt
index eb633a814333e..ad5017369b0a7 100644
--- a/libc/test/src/time/CMakeLists.txt
+++ b/libc/test/src/time/CMakeLists.txt
@@ -226,6 +226,17 @@ add_libc_test(
     libc.src.time.strftime
 )
 
+add_libc_test(
+  strptime_test
+  SUITE
+    libc_time_unittests
+  SRCS
+    strptime_test.cpp
+  DEPENDS
+    libc.hdr.types.struct_tm
+    libc.src.time.strptime
+)
+
 add_libc_unittest(
   time_test
   SUITE
diff --git a/libc/test/src/time/strptime_test.cpp b/libc/test/src/time/strptime_test.cpp
new file mode 100644
index 0000000000000..f5b84ec5c8932
--- /dev/null
+++ b/libc/test/src/time/strptime_test.cpp
@@ -0,0 +1,19 @@
+//===-- Unittests for strptime --------------------------------------------===//
+//
+// 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/struct_tm.h"
+#include "src/time/strptime.h"
+#include "test/UnitTest/Test.h"
+
+TEST(LlvmLibcStrptimeTest, StubReturnsNull) {
+  struct tm time;
+  char *result;
+
+  result = LIBC_NAMESPACE::strptime("13:23:45", "%T", &time);
+  EXPECT_EQ(result, nullptr);
+}

>From e5f424ea8b94648f8a5c02214b4f3705bd2bcc2c Mon Sep 17 00:00:00 2001
From: Alex Strelnikov <strel at google.com>
Date: Tue, 21 Jul 2026 19:11:50 +0000
Subject: [PATCH 2/3] Add missing CMakeLists dependency edit.

---
 libc/src/time/CMakeLists.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libc/src/time/CMakeLists.txt b/libc/src/time/CMakeLists.txt
index d4ccc0ce4b4f3..3b8110ade345e 100644
--- a/libc/src/time/CMakeLists.txt
+++ b/libc/src/time/CMakeLists.txt
@@ -222,6 +222,7 @@ add_entrypoint_object(
     strptime.h
   DEPENDS
     libc.hdr.types.struct_tm
+    libc.src.__support.common
     libc.src.__support.macros.config
 )
 

>From 7644c7b747bafb70f91f927a904409cb9007c871 Mon Sep 17 00:00:00 2001
From: Alex Strelnikov <strel at google.com>
Date: Tue, 21 Jul 2026 19:49:21 +0000
Subject: [PATCH 3/3] Fix file headers to use the current format.

---
 libc/src/time/strptime.cpp           | 7 ++++++-
 libc/src/time/strptime.h             | 7 ++++++-
 libc/test/src/time/strptime_test.cpp | 7 ++++++-
 3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/libc/src/time/strptime.cpp b/libc/src/time/strptime.cpp
index e1d099034fc04..6e71ecde0e0ef 100644
--- a/libc/src/time/strptime.cpp
+++ b/libc/src/time/strptime.cpp
@@ -1,10 +1,15 @@
-//===-- Implementation of strptime function -------------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file contains the definition of the strptime function.
+///
+//===----------------------------------------------------------------------===//
 
 #include "src/time/strptime.h"
 #include "hdr/types/struct_tm.h"
diff --git a/libc/src/time/strptime.h b/libc/src/time/strptime.h
index 15107dcdd64b5..6678c42f0b304 100644
--- a/libc/src/time/strptime.h
+++ b/libc/src/time/strptime.h
@@ -1,10 +1,15 @@
-//===-- Implementation header of strptime -----------------------*- 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
 //
 //===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file contains the declaration of the strptime function.
+///
+//===----------------------------------------------------------------------===//
 
 #ifndef LLVM_LIBC_SRC_TIME_STRPTIME_H
 #define LLVM_LIBC_SRC_TIME_STRPTIME_H
diff --git a/libc/test/src/time/strptime_test.cpp b/libc/test/src/time/strptime_test.cpp
index f5b84ec5c8932..8248e76589a8e 100644
--- a/libc/test/src/time/strptime_test.cpp
+++ b/libc/test/src/time/strptime_test.cpp
@@ -1,10 +1,15 @@
-//===-- Unittests for strptime --------------------------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file contains unit tests for strptime.
+///
+//===----------------------------------------------------------------------===//
 
 #include "hdr/types/struct_tm.h"
 #include "src/time/strptime.h"

More information about the libc-commits mailing list