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2 changes: 2 additions & 0 deletions libcxx/CMakeLists.txt
Original file line number Diff line number Diff line change
Expand Up @@ -285,6 +285,7 @@ endif()

# Feature options -------------------------------------------------------------
option(LIBCXX_HAS_MUSL_LIBC "Build libc++ with support for the Musl C library" OFF)
option(LIBCXX_HAS_NEWLIB_LIBC "Build libc++ with support for the Newlib C library" OFF)
option(LIBCXX_HAS_PTHREAD_API "Ignore auto-detection and force use of pthread API" OFF)
option(LIBCXX_HAS_WIN32_THREAD_API "Ignore auto-detection and force use of win32 thread API" OFF)
option(LIBCXX_HAS_EXTERNAL_THREAD_API
Expand Down Expand Up @@ -741,6 +742,7 @@ config_define(${LIBCXX_HAS_PTHREAD_API} _LIBCPP_HAS_THREAD_API_PTHREAD)
config_define(${LIBCXX_HAS_EXTERNAL_THREAD_API} _LIBCPP_HAS_THREAD_API_EXTERNAL)
config_define(${LIBCXX_HAS_WIN32_THREAD_API} _LIBCPP_HAS_THREAD_API_WIN32)
config_define(${LIBCXX_HAS_MUSL_LIBC} _LIBCPP_HAS_MUSL_LIBC)
config_define(${LIBCXX_HAS_NEWLIB_LIBC} _LIBCPP_HAS_NEWLIB_LIBC)
config_define_if(LIBCXX_NO_VCRUNTIME _LIBCPP_NO_VCRUNTIME)
config_define(${LIBCXX_ENABLE_FILESYSTEM} _LIBCPP_HAS_FILESYSTEM)
config_define(${LIBCXX_ENABLE_RANDOM_DEVICE} _LIBCPP_HAS_RANDOM_DEVICE)
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1 change: 1 addition & 0 deletions libcxx/include/CMakeLists.txt
Original file line number Diff line number Diff line change
Expand Up @@ -533,6 +533,7 @@ set(files
__locale_dir/support/fuchsia.h
__locale_dir/support/linux.h
__locale_dir/support/netbsd.h
__locale_dir/support/newlib.h
__locale_dir/support/no_locale/characters.h
__locale_dir/support/no_locale/strtonum.h
__locale_dir/support/windows.h
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1 change: 1 addition & 0 deletions libcxx/include/__config_site.in
Original file line number Diff line number Diff line change
Expand Up @@ -17,6 +17,7 @@
#cmakedefine01 _LIBCPP_HAS_MONOTONIC_CLOCK
#cmakedefine01 _LIBCPP_HAS_TERMINAL
#cmakedefine01 _LIBCPP_HAS_MUSL_LIBC
#cmakedefine01 _LIBCPP_HAS_NEWLIB_LIBC
#cmakedefine01 _LIBCPP_HAS_THREAD_API_PTHREAD
#cmakedefine01 _LIBCPP_HAS_THREAD_API_EXTERNAL
#cmakedefine01 _LIBCPP_HAS_THREAD_API_WIN32
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2 changes: 2 additions & 0 deletions libcxx/include/__locale_dir/locale_base_api.h
Original file line number Diff line number Diff line change
Expand Up @@ -123,6 +123,8 @@
# include <__locale_dir/support/fuchsia.h>
# elif defined(__linux__)
# include <__locale_dir/support/linux.h>
# elif _LIBCPP_HAS_NEWLIB_LIBC
# include <__locale_dir/support/newlib.h>
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Is Newlib ever used on a platform where __linux__ is defined? It seems to me like we might be checking the wrong thing by checking elif defined(__linux__) above, perhaps what we want is elif defined(_GLIBC)?

Also CC @reactive-firewall

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@wecing

However, I recently realized that the -Dxxx approach might actually be okay, because it just exposes things that are compiled and included in libc.a anyways.

  • Regarding bare-metal I generally agree;
    • TL;DR - the __linux__ flag just declares the presence of the linux headers, which may or may not be relevant to the libc (which by standard (e.g. ISO 9989: ) has no requirement on the linux headers, e.g., musl and BSD libc can compile without the linux headers) so baremetal builds should not expect it to describe libc.

EDIT: @ldionne

  • It seems to me like we might be checking the wrong thing by checking elif defined(__linux__) above, perhaps what we want is elif defined(_GLIBC)?
    • IIUC newlib has its requirements on a small subset of OS provided functions (with minimal implementations suggested in the docs), and is well suited to building without the __linux__ being defined when bootstraping a stage0 toolset, (possibly even for an eventual linux system). AFAIK, newlib does seem to provide the strto*_l functions unconditionally (albeit not sure where in their codebase 🤷)
    • musl libc has no requirement on linux headers even when building for linux, rather they guard things based on macros like _GNU_SOURCE or _BSD_SOURCE
    • IIUC glibc defines linux somewhere (I know GNU compilers pre-define it, albeit GNU lib != GNU compiler), so while misleading, may be correct in the specific case for identifying "official" (e.g. non-llvm) linux builds. However, _GLIBC would be more intuitive and granular for identifying the particular standard c library (e.g. glibc, stdlibc, libc, libsystem_c etc.)

In summation: elif defined(_GLIBC) seems more granular and maintainable regarding near-baremetal (e.g. just minimal libc) use-cases.

🙇 Hopefully this helps.

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Thank you for the review and insights, @ldionne and @reactive-firewall !

AFAIK, newlib does seem to provide the strto*_l functions unconditionally (albeit not sure where in their codebase 🤷)

For the record, they are defined in the non-_l .c files, e.g. newlib/libc/stdlib/strtol.c for strtol_l.

perhaps what we want is elif defined(_GLIBC)?

Per my discussion with @philnik777 above, linux.h and newlib.h are essentially the same. So it sounds like we need something like this:

#  elif defined(_GLIBC) || _LIBCPP_LIBC_NEWLIB
#    include <__locale_dir/support/minimal_libc.h>

And rename linux.h to minimal_libc.h?

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It's going to sound weird, but for the moment I think I'd rather keep the changes minimal even if it incurs some code duplication. So for this patch, I prefer the current approach with

#  elif _LIBCPP_LIBC_NEWLIB
#    include <__locale_dir/support/newlib.h>

The reason is that I already want to formalize the way we define the C library we use, so there's some refactoring I'll need to do in that area. I also want to further refactor some of the localization base API stuff to better support LLVM-libc. So for the time being, please just follow the status quo closely and I'll think about how to refactor this in the future to reduce duplication a bit.

# else

// TODO: This is a temporary definition to bridge between the old way we defined the locale base API
Expand Down
269 changes: 269 additions & 0 deletions libcxx/include/__locale_dir/support/newlib.h
Original file line number Diff line number Diff line change
@@ -0,0 +1,269 @@
//===-----------------------------------------------------------------------===//
//
// 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 _LIBCPP___LOCALE_DIR_SUPPORT_NEWLIB_H
#define _LIBCPP___LOCALE_DIR_SUPPORT_NEWLIB_H

#include <__config>
#include <clocale>
#include <cstdio>
#include <cstdlib>
#include <ctype.h>
#include <stdarg.h>
#include <string.h>
#include <time.h>
#if _LIBCPP_HAS_WIDE_CHARACTERS
# include <cwchar>
# include <wctype.h>
#endif

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif

_LIBCPP_BEGIN_NAMESPACE_STD
namespace __locale {

struct __locale_guard {
_LIBCPP_HIDE_FROM_ABI __locale_guard(locale_t& __loc) : __old_loc_(::uselocale(__loc)) {}

_LIBCPP_HIDE_FROM_ABI ~__locale_guard() {
if (__old_loc_)
::uselocale(__old_loc_);
}

locale_t __old_loc_;

__locale_guard(__locale_guard const&) = delete;
__locale_guard& operator=(__locale_guard const&) = delete;
};

//
// Locale management
//

using __locale_t _LIBCPP_NODEBUG = locale_t;
using __lconv_t _LIBCPP_NODEBUG = lconv;

inline _LIBCPP_HIDE_FROM_ABI __locale_t __newlocale(int __category_mask, const char* __locale, __locale_t __base) {
return ::newlocale(__category_mask, __locale, __base);
}

inline _LIBCPP_HIDE_FROM_ABI void __freelocale(__locale_t __loc) { ::freelocale(__loc); }

inline _LIBCPP_HIDE_FROM_ABI char* __setlocale(int __category, char const* __locale) {
return ::setlocale(__category, __locale);
}

inline _LIBCPP_HIDE_FROM_ABI __lconv_t* __localeconv(__locale_t& __loc) {
__locale_guard __current(__loc);
return std::localeconv();
}

#define _LIBCPP_COLLATE_MASK LC_COLLATE_MASK
#define _LIBCPP_CTYPE_MASK LC_CTYPE_MASK
#define _LIBCPP_MONETARY_MASK LC_MONETARY_MASK
#define _LIBCPP_NUMERIC_MASK LC_NUMERIC_MASK
#define _LIBCPP_TIME_MASK LC_TIME_MASK
#define _LIBCPP_MESSAGES_MASK LC_MESSAGES_MASK
#define _LIBCPP_ALL_MASK LC_ALL_MASK
#define _LIBCPP_LC_ALL LC_ALL

//
// Strtonum functions
//

inline _LIBCPP_HIDE_FROM_ABI float __strtof(const char* __nptr, char** __endptr, __locale_t __loc) {
return ::strtof_l(__nptr, __endptr, __loc);
}

inline _LIBCPP_HIDE_FROM_ABI double __strtod(const char* __nptr, char** __endptr, __locale_t __loc) {
return ::strtod_l(__nptr, __endptr, __loc);
}

inline _LIBCPP_HIDE_FROM_ABI long double __strtold(const char* __nptr, char** __endptr, __locale_t __loc) {
return ::strtold_l(__nptr, __endptr, __loc);
}

inline _LIBCPP_HIDE_FROM_ABI long long __strtoll(const char* __nptr, char** __endptr, int __base, __locale_t __loc) {
return ::strtoll_l(__nptr, __endptr, __base, __loc);
}

inline _LIBCPP_HIDE_FROM_ABI unsigned long long
__strtoull(const char* __nptr, char** __endptr, int __base, __locale_t __loc) {
return ::strtoull_l(__nptr, __endptr, __base, __loc);
}

//
// Character manipulation functions
//

inline _LIBCPP_HIDE_FROM_ABI int __isdigit(int __c, __locale_t __loc) { return isdigit_l(__c, __loc); }

inline _LIBCPP_HIDE_FROM_ABI int __isxdigit(int __c, __locale_t __loc) { return isxdigit_l(__c, __loc); }

#if defined(_LIBCPP_BUILDING_LIBRARY)
inline _LIBCPP_HIDE_FROM_ABI int __toupper(int __c, __locale_t __loc) { return toupper_l(__c, __loc); }

inline _LIBCPP_HIDE_FROM_ABI int __tolower(int __c, __locale_t __loc) { return tolower_l(__c, __loc); }

inline _LIBCPP_HIDE_FROM_ABI int __strcoll(const char* __s1, const char* __s2, __locale_t __loc) {
return strcoll_l(__s1, __s2, __loc);
}

inline _LIBCPP_HIDE_FROM_ABI size_t __strxfrm(char* __dest, const char* __src, size_t __n, __locale_t __loc) {
return strxfrm_l(__dest, __src, __n, __loc);
}

# if _LIBCPP_HAS_WIDE_CHARACTERS
inline _LIBCPP_HIDE_FROM_ABI int __iswctype(wint_t __c, wctype_t __type, __locale_t __loc) {
return iswctype_l(__c, __type, __loc);
}

inline _LIBCPP_HIDE_FROM_ABI int __iswspace(wint_t __c, __locale_t __loc) { return iswspace_l(__c, __loc); }

inline _LIBCPP_HIDE_FROM_ABI int __iswprint(wint_t __c, __locale_t __loc) { return iswprint_l(__c, __loc); }

inline _LIBCPP_HIDE_FROM_ABI int __iswcntrl(wint_t __c, __locale_t __loc) { return iswcntrl_l(__c, __loc); }

inline _LIBCPP_HIDE_FROM_ABI int __iswupper(wint_t __c, __locale_t __loc) { return iswupper_l(__c, __loc); }

inline _LIBCPP_HIDE_FROM_ABI int __iswlower(wint_t __c, __locale_t __loc) { return iswlower_l(__c, __loc); }

inline _LIBCPP_HIDE_FROM_ABI int __iswalpha(wint_t __c, __locale_t __loc) { return iswalpha_l(__c, __loc); }

inline _LIBCPP_HIDE_FROM_ABI int __iswblank(wint_t __c, __locale_t __loc) { return iswblank_l(__c, __loc); }

inline _LIBCPP_HIDE_FROM_ABI int __iswdigit(wint_t __c, __locale_t __loc) { return iswdigit_l(__c, __loc); }

inline _LIBCPP_HIDE_FROM_ABI int __iswpunct(wint_t __c, __locale_t __loc) { return iswpunct_l(__c, __loc); }

inline _LIBCPP_HIDE_FROM_ABI int __iswxdigit(wint_t __c, __locale_t __loc) { return iswxdigit_l(__c, __loc); }

inline _LIBCPP_HIDE_FROM_ABI wint_t __towupper(wint_t __c, __locale_t __loc) { return towupper_l(__c, __loc); }

inline _LIBCPP_HIDE_FROM_ABI wint_t __towlower(wint_t __c, __locale_t __loc) { return towlower_l(__c, __loc); }

inline _LIBCPP_HIDE_FROM_ABI int __wcscoll(const wchar_t* __ws1, const wchar_t* __ws2, __locale_t __loc) {
return wcscoll_l(__ws1, __ws2, __loc);
}

inline _LIBCPP_HIDE_FROM_ABI size_t __wcsxfrm(wchar_t* __dest, const wchar_t* __src, size_t __n, __locale_t __loc) {
return wcsxfrm_l(__dest, __src, __n, __loc);
}
# endif // _LIBCPP_HAS_WIDE_CHARACTERS

inline _LIBCPP_HIDE_FROM_ABI
size_t __strftime(char* __s, size_t __max, const char* __format, const struct tm* __tm, __locale_t __loc) {
return strftime_l(__s, __max, __format, __tm, __loc);
}

//
// Other functions
//

inline _LIBCPP_HIDE_FROM_ABI decltype(MB_CUR_MAX) __mb_len_max(__locale_t __loc) {
__locale_guard __current(__loc);
return MB_CUR_MAX;
}

# if _LIBCPP_HAS_WIDE_CHARACTERS
inline _LIBCPP_HIDE_FROM_ABI wint_t __btowc(int __c, __locale_t __loc) {
__locale_guard __current(__loc);
return std::btowc(__c);
}

inline _LIBCPP_HIDE_FROM_ABI int __wctob(wint_t __c, __locale_t __loc) {
__locale_guard __current(__loc);
return std::wctob(__c);
}

inline _LIBCPP_HIDE_FROM_ABI size_t
__wcsnrtombs(char* __dest, const wchar_t** __src, size_t __nwc, size_t __len, mbstate_t* __ps, __locale_t __loc) {
__locale_guard __current(__loc);
return ::wcsnrtombs(__dest, __src, __nwc, __len, __ps); // non-standard
}

inline _LIBCPP_HIDE_FROM_ABI size_t __wcrtomb(char* __s, wchar_t __wc, mbstate_t* __ps, __locale_t __loc) {
__locale_guard __current(__loc);
return std::wcrtomb(__s, __wc, __ps);
}

inline _LIBCPP_HIDE_FROM_ABI size_t
__mbsnrtowcs(wchar_t* __dest, const char** __src, size_t __nms, size_t __len, mbstate_t* __ps, __locale_t __loc) {
__locale_guard __current(__loc);
return ::mbsnrtowcs(__dest, __src, __nms, __len, __ps); // non-standard
}

inline _LIBCPP_HIDE_FROM_ABI size_t
__mbrtowc(wchar_t* __pwc, const char* __s, size_t __n, mbstate_t* __ps, __locale_t __loc) {
__locale_guard __current(__loc);
return std::mbrtowc(__pwc, __s, __n, __ps);
}

inline _LIBCPP_HIDE_FROM_ABI int __mbtowc(wchar_t* __pwc, const char* __pmb, size_t __max, __locale_t __loc) {
__locale_guard __current(__loc);
return std::mbtowc(__pwc, __pmb, __max);
}

inline _LIBCPP_HIDE_FROM_ABI size_t __mbrlen(const char* __s, size_t __n, mbstate_t* __ps, __locale_t __loc) {
__locale_guard __current(__loc);
return std::mbrlen(__s, __n, __ps);
}

inline _LIBCPP_HIDE_FROM_ABI size_t
__mbsrtowcs(wchar_t* __dest, const char** __src, size_t __len, mbstate_t* __ps, __locale_t __loc) {
__locale_guard __current(__loc);
return std::mbsrtowcs(__dest, __src, __len, __ps);
}
# endif // _LIBCPP_HAS_WIDE_CHARACTERS
#endif // _LIBCPP_BUILDING_LIBRARY

#ifndef _LIBCPP_COMPILER_GCC // GCC complains that this can't be always_inline due to C-style varargs
_LIBCPP_HIDE_FROM_ABI
#endif
inline _LIBCPP_ATTRIBUTE_FORMAT(__printf__, 4, 5) int __snprintf(
char* __s, size_t __n, __locale_t __loc, const char* __format, ...) {
va_list __va;
va_start(__va, __format);
__locale_guard __current(__loc);
int __res = std::vsnprintf(__s, __n, __format, __va);
va_end(__va);
return __res;
}

#ifndef _LIBCPP_COMPILER_GCC // GCC complains that this can't be always_inline due to C-style varargs
_LIBCPP_HIDE_FROM_ABI
#endif
inline _LIBCPP_ATTRIBUTE_FORMAT(__printf__, 3, 4) int __asprintf(
char** __s, __locale_t __loc, const char* __format, ...) {
va_list __va;
va_start(__va, __format);
__locale_guard __current(__loc);
int __res = ::vasprintf(__s, __format, __va); // non-standard
va_end(__va);
return __res;
}

#ifndef _LIBCPP_COMPILER_GCC // GCC complains that this can't be always_inline due to C-style varargs
_LIBCPP_HIDE_FROM_ABI
#endif
inline _LIBCPP_ATTRIBUTE_FORMAT(__scanf__, 3, 4) int __sscanf(
const char* __s, __locale_t __loc, const char* __format, ...) {
va_list __va;
va_start(__va, __format);
__locale_guard __current(__loc);
int __res = std::vsscanf(__s, __format, __va);
va_end(__va);
return __res;
}

} // namespace __locale
_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP___LOCALE_DIR_SUPPORT_NEWLIB_H
1 change: 1 addition & 0 deletions libcxx/include/module.modulemap.in
Original file line number Diff line number Diff line change
Expand Up @@ -1591,6 +1591,7 @@ module std [system] {
textual header "__locale_dir/support/fuchsia.h"
textual header "__locale_dir/support/linux.h"
textual header "__locale_dir/support/netbsd.h"
textual header "__locale_dir/support/newlib.h"
textual header "__locale_dir/support/no_locale/characters.h"
textual header "__locale_dir/support/no_locale/strtonum.h"
textual header "__locale_dir/support/windows.h"
Expand Down
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