[libcxx-commits] [libcxx] [libc++] Fix C++23 standard modules when using with `clang-cl` on Windows (PR #148992)
via libcxx-commits
libcxx-commits at lists.llvm.org
Sat Jul 19 19:14:25 PDT 2025
https://github.com/siradam7th updated https://github.com/llvm/llvm-project/pull/148992
>From ed2c4e4947d9f703675acdc0dad3c380fb0a390a Mon Sep 17 00:00:00 2001
From: siradam7th <siradam7th at users.noreply.github.com>
Date: Wed, 16 Jul 2025 00:35:50 +0100
Subject: [PATCH 1/4] fix libc++ std modules compilation on Windows using
clang-cl
---
libcxx/include/__new/new_handler.h | 5 +++++
libcxx/modules/std.compat/ctime.inc | 6 ++++--
libcxx/modules/std.cppm.in | 3 +++
libcxx/modules/std/ctime.inc | 6 ++++--
4 files changed, 16 insertions(+), 4 deletions(-)
diff --git a/libcxx/include/__new/new_handler.h b/libcxx/include/__new/new_handler.h
index 05f4e846c3ef9..2350f9ae9bc19 100644
--- a/libcxx/include/__new/new_handler.h
+++ b/libcxx/include/__new/new_handler.h
@@ -17,6 +17,11 @@
#if defined(_LIBCPP_ABI_VCRUNTIME)
# include <new.h>
+// <new.h> does not define 'get_new_handler'
+// which makes the 'std' module build fail, this fixes it
+namespace std {
+_LIBCPP_EXPORTED_FROM_ABI new_handler get_new_handler() _NOEXCEPT;
+}
#else
_LIBCPP_BEGIN_UNVERSIONED_NAMESPACE_STD
typedef void (*new_handler)();
diff --git a/libcxx/modules/std.compat/ctime.inc b/libcxx/modules/std.compat/ctime.inc
index eba8234a08969..7547b055b6807 100644
--- a/libcxx/modules/std.compat/ctime.inc
+++ b/libcxx/modules/std.compat/ctime.inc
@@ -14,15 +14,17 @@ export {
using ::timespec _LIBCPP_USING_IF_EXISTS;
using ::tm _LIBCPP_USING_IF_EXISTS;
-
using ::asctime _LIBCPP_USING_IF_EXISTS;
using ::clock _LIBCPP_USING_IF_EXISTS;
+ using ::strftime _LIBCPP_USING_IF_EXISTS;
+
+#ifndef _LIBCPP_ABI_VCRUNTIME
using ::ctime _LIBCPP_USING_IF_EXISTS;
using ::difftime _LIBCPP_USING_IF_EXISTS;
using ::gmtime _LIBCPP_USING_IF_EXISTS;
using ::localtime _LIBCPP_USING_IF_EXISTS;
using ::mktime _LIBCPP_USING_IF_EXISTS;
- using ::strftime _LIBCPP_USING_IF_EXISTS;
using ::time _LIBCPP_USING_IF_EXISTS;
using ::timespec_get _LIBCPP_USING_IF_EXISTS;
+#endif
} // export
diff --git a/libcxx/modules/std.cppm.in b/libcxx/modules/std.cppm.in
index 984b18321923c..f19dc07169fda 100644
--- a/libcxx/modules/std.cppm.in
+++ b/libcxx/modules/std.cppm.in
@@ -51,6 +51,9 @@ module;
#include <cstdio>
#include <cstdlib>
#include <cstring>
+#ifdef _LIBCPP_ABI_VCRUNTIME
+#define _BUILD_STD_MODULE
+#endif
#include <ctime>
#include <cuchar>
#include <cwchar>
diff --git a/libcxx/modules/std/ctime.inc b/libcxx/modules/std/ctime.inc
index 5bfa61917e5f2..e9f8ecb6ec63e 100644
--- a/libcxx/modules/std/ctime.inc
+++ b/libcxx/modules/std/ctime.inc
@@ -14,15 +14,17 @@ export namespace std {
using std::timespec _LIBCPP_USING_IF_EXISTS;
using std::tm _LIBCPP_USING_IF_EXISTS;
-
using std::asctime _LIBCPP_USING_IF_EXISTS;
using std::clock _LIBCPP_USING_IF_EXISTS;
+ using std::strftime _LIBCPP_USING_IF_EXISTS;
+
+#ifndef _LIBCPP_ABI_VCRUNTIME
using std::ctime _LIBCPP_USING_IF_EXISTS;
using std::difftime _LIBCPP_USING_IF_EXISTS;
using std::gmtime _LIBCPP_USING_IF_EXISTS;
using std::localtime _LIBCPP_USING_IF_EXISTS;
using std::mktime _LIBCPP_USING_IF_EXISTS;
- using std::strftime _LIBCPP_USING_IF_EXISTS;
using std::time _LIBCPP_USING_IF_EXISTS;
using std::timespec_get _LIBCPP_USING_IF_EXISTS;
+#endif
} // namespace std
>From b6bf097211fc8755f233a8c81d7248910da03529 Mon Sep 17 00:00:00 2001
From: siradam7th <siradam7th at users.noreply.github.com>
Date: Sun, 20 Jul 2025 02:49:00 +0100
Subject: [PATCH 2/4] fix python file encoding error on Windows
---
libcxx/utils/generate_libcxx_cppm_in.py | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/libcxx/utils/generate_libcxx_cppm_in.py b/libcxx/utils/generate_libcxx_cppm_in.py
index 39076a61b55b8..4e0d39289f33e 100644
--- a/libcxx/utils/generate_libcxx_cppm_in.py
+++ b/libcxx/utils/generate_libcxx_cppm_in.py
@@ -9,11 +9,19 @@
import os.path
import sys
-from libcxx.header_information import module_c_headers, module_headers, header_restrictions, headers_not_available, libcxx_root
+from libcxx.header_information import (
+ module_c_headers,
+ module_headers,
+ header_restrictions,
+ headers_not_available,
+ libcxx_root,
+)
def write_file(module):
- with open(libcxx_root / "modules" / f"{module}.cppm.in", "w") as module_cpp_in:
+ with open(
+ libcxx_root / "modules" / f"{module}.cppm.in", "w", encoding="utf-8"
+ ) as module_cpp_in:
module_cpp_in.write(
"""\
// -*- C++ -*-
@@ -25,6 +33,7 @@ def write_file(module):
//
//===----------------------------------------------------------------------===//
+
// WARNING, this entire header is generated by
// utils/generate_libcxx_cppm_in.py
// DO NOT MODIFY!
>From 4e7a4c990be91e342baff24742d343c868d7970f Mon Sep 17 00:00:00 2001
From: siradam7th <siradam7th at users.noreply.github.com>
Date: Sun, 20 Jul 2025 02:58:17 +0100
Subject: [PATCH 3/4] add missing functions defined as inline, remove
'_BUILD_STD_MODULE'
---
libcxx/modules/std.compat/ctime.inc | 40 ++++++++++++++++++++++++++++
libcxx/modules/std.cppm.in | 3 ---
libcxx/modules/std/ctime.inc | 41 +++++++++++++++++++++++++++++
3 files changed, 81 insertions(+), 3 deletions(-)
diff --git a/libcxx/modules/std.compat/ctime.inc b/libcxx/modules/std.compat/ctime.inc
index 7547b055b6807..dbaf76fe6363d 100644
--- a/libcxx/modules/std.compat/ctime.inc
+++ b/libcxx/modules/std.compat/ctime.inc
@@ -27,4 +27,44 @@ export {
using ::time _LIBCPP_USING_IF_EXISTS;
using ::timespec_get _LIBCPP_USING_IF_EXISTS;
#endif
+
+// A workaround for UCRT because it defines these functions
+// as static and that causes the error "internal linkage cannot be exported"
+#ifdef _LIBCPP_ABI_VCRUNTIME
+
+ template <int = 0>
+ inline char* __CRTDECL ctime(_In_ time_t const* const _Time) noexcept {
+ return _ctime64(_Time);
+ }
+
+ template <int = 0>
+ inline double __CRTDECL difftime(_In_ time_t const _Time1, _In_ time_t const _Time2) noexcept {
+ return _difftime64(_Time1, _Time2);
+ }
+
+ template <int = 0>
+ inline tm* __CRTDECL gmtime(_In_ time_t const* const _Time) noexcept {
+ return _gmtime64(_Time);
+ }
+
+ template <int = 0>
+ inline tm* __CRTDECL localtime(_In_ time_t const* const _Time) noexcept {
+ return _localtime64(_Time);
+ }
+
+ template <int = 0>
+ inline time_t __CRTDECL mktime(_Inout_ tm* const _Tm) noexcept {
+ return _mktime64(_Tm);
+ }
+
+ template <int = 0>
+ inline time_t __CRTDECL time(_Out_opt_ time_t* const _Time) noexcept {
+ return _time64(_Time);
+ }
+
+ template <int = 0>
+ inline int __CRTDECL timespec_get(_Out_ timespec* const _Ts, _In_ int const _Base) noexcept {
+ return _timespec64_get(reinterpret_cast<_timespec64*>(_Ts), _Base);
+ }
+#endif
} // export
diff --git a/libcxx/modules/std.cppm.in b/libcxx/modules/std.cppm.in
index f19dc07169fda..984b18321923c 100644
--- a/libcxx/modules/std.cppm.in
+++ b/libcxx/modules/std.cppm.in
@@ -51,9 +51,6 @@ module;
#include <cstdio>
#include <cstdlib>
#include <cstring>
-#ifdef _LIBCPP_ABI_VCRUNTIME
-#define _BUILD_STD_MODULE
-#endif
#include <ctime>
#include <cuchar>
#include <cwchar>
diff --git a/libcxx/modules/std/ctime.inc b/libcxx/modules/std/ctime.inc
index e9f8ecb6ec63e..4caa9d3e33d36 100644
--- a/libcxx/modules/std/ctime.inc
+++ b/libcxx/modules/std/ctime.inc
@@ -14,6 +14,7 @@ export namespace std {
using std::timespec _LIBCPP_USING_IF_EXISTS;
using std::tm _LIBCPP_USING_IF_EXISTS;
+
using std::asctime _LIBCPP_USING_IF_EXISTS;
using std::clock _LIBCPP_USING_IF_EXISTS;
using std::strftime _LIBCPP_USING_IF_EXISTS;
@@ -27,4 +28,44 @@ export namespace std {
using std::time _LIBCPP_USING_IF_EXISTS;
using std::timespec_get _LIBCPP_USING_IF_EXISTS;
#endif
+
+// A workaround for UCRT because it defines these functions
+// as static and that causes the error "internal linkage cannot be exported"
+#ifdef _LIBCPP_ABI_VCRUNTIME
+
+ template <int = 0>
+ inline char* __CRTDECL ctime(_In_ time_t const* const _Time) noexcept {
+ return _ctime64(_Time);
+ }
+
+ template <int = 0>
+ inline double __CRTDECL difftime(_In_ time_t const _Time1, _In_ time_t const _Time2) noexcept {
+ return _difftime64(_Time1, _Time2);
+ }
+
+ template <int = 0>
+ inline tm* __CRTDECL gmtime(_In_ time_t const* const _Time) noexcept {
+ return _gmtime64(_Time);
+ }
+
+ template <int = 0>
+ inline tm* __CRTDECL localtime(_In_ time_t const* const _Time) noexcept {
+ return _localtime64(_Time);
+ }
+
+ template <int = 0>
+ inline time_t __CRTDECL mktime(_Inout_ tm* const _Tm) noexcept {
+ return _mktime64(_Tm);
+ }
+
+ template <int = 0>
+ inline time_t __CRTDECL time(_Out_opt_ time_t* const _Time) noexcept {
+ return _time64(_Time);
+ }
+
+ template <int = 0>
+ inline int __CRTDECL timespec_get(_Out_ timespec* const _Ts, _In_ int const _Base) noexcept {
+ return _timespec64_get(reinterpret_cast<_timespec64*>(_Ts), _Base);
+ }
+#endif
} // namespace std
>From bf7ca141d4366bdef2cca482e89624fddf5362ce Mon Sep 17 00:00:00 2001
From: siradam7th <siradam7th at users.noreply.github.com>
Date: Sun, 20 Jul 2025 03:12:45 +0100
Subject: [PATCH 4/4] remove 'FIXME' for 'get_new_handler()' test
---
.../alloc.errors/set.new.handler/get_new_handler.pass.cpp | 6 ------
1 file changed, 6 deletions(-)
diff --git a/libcxx/test/std/language.support/support.dynamic/alloc.errors/set.new.handler/get_new_handler.pass.cpp b/libcxx/test/std/language.support/support.dynamic/alloc.errors/set.new.handler/get_new_handler.pass.cpp
index c5725bde6e6c3..2c0081703760e 100644
--- a/libcxx/test/std/language.support/support.dynamic/alloc.errors/set.new.handler/get_new_handler.pass.cpp
+++ b/libcxx/test/std/language.support/support.dynamic/alloc.errors/set.new.handler/get_new_handler.pass.cpp
@@ -8,12 +8,6 @@
// test get_new_handler
-// FIXME: When libc++ is linked against vcruntime (i.e. the default config in
-// MSVC mode), the declarations of std::set_new_handler and std::get_new_handler
-// are provided by vcruntime/UCRT's new.h. However, that header actually only
-// declares set_new_handler - it's missing a declaration of get_new_handler.
-
-// XFAIL: msvc && stdlib=libc++
#include <new>
#include <cassert>
More information about the libcxx-commits
mailing list