libstdc++: Fix C++ 11 ctype when using picolibc (blank vs space)
Commit Message
Existing toolchain builds rely on the similarity between picolibc and
newlib when building libstdc++ and use --with-newlib.
Switch to the picolibc 16-bit _ctype_wide array which provides
separate values for ctype_base::blank and ctype_base::space.
This fixes a bug where libstdc++ was including '\f', '\n', '\r' and
'\v' in the set of 'blank' chars. Afterwards, only ' ' and '\t' are in
this set, as specified by C++ 11.
Signed-off-by: Keith Packard <keithp@keithp.com>
---
libstdc++-v3/acinclude.m4 | 4 +
libstdc++-v3/config/os/picolibc/ctype_base.h | 61 ++++++++++
.../os/picolibc/ctype_configure_char.cc | 105 ++++++++++++++++++
.../config/os/picolibc/ctype_inline.h | 74 ++++++++++++
libstdc++-v3/config/os/picolibc/os_defines.h | 36 ++++++
libstdc++-v3/configure.ac | 62 +++++++++++
6 files changed, 342 insertions(+)
create mode 100644 libstdc++-v3/config/os/picolibc/ctype_base.h
create mode 100644 libstdc++-v3/config/os/picolibc/ctype_configure_char.cc
create mode 100644 libstdc++-v3/config/os/picolibc/ctype_inline.h
create mode 100644 libstdc++-v3/config/os/picolibc/os_defines.h
Comments
On Thu, 8 Jan 2026 at 18:14, Keith Packard <keithp@keithp.com> wrote:
>
> Existing toolchain builds rely on the similarity between picolibc and
> newlib when building libstdc++ and use --with-newlib.
>
> Switch to the picolibc 16-bit _ctype_wide array which provides
> separate values for ctype_base::blank and ctype_base::space.
>
> This fixes a bug where libstdc++ was including '\f', '\n', '\r' and
> '\v' in the set of 'blank' chars. Afterwards, only ' ' and '\t' are in
> this set, as specified by C++ 11.
Thanks, this looks good now. I'll push it after some local checks.
>
> Signed-off-by: Keith Packard <keithp@keithp.com>
> ---
> libstdc++-v3/acinclude.m4 | 4 +
> libstdc++-v3/config/os/picolibc/ctype_base.h | 61 ++++++++++
> .../os/picolibc/ctype_configure_char.cc | 105 ++++++++++++++++++
> .../config/os/picolibc/ctype_inline.h | 74 ++++++++++++
> libstdc++-v3/config/os/picolibc/os_defines.h | 36 ++++++
> libstdc++-v3/configure.ac | 62 +++++++++++
> 6 files changed, 342 insertions(+)
> create mode 100644 libstdc++-v3/config/os/picolibc/ctype_base.h
> create mode 100644 libstdc++-v3/config/os/picolibc/ctype_configure_char.cc
> create mode 100644 libstdc++-v3/config/os/picolibc/ctype_inline.h
> create mode 100644 libstdc++-v3/config/os/picolibc/os_defines.h
>
> diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
> index 103515c000f..1eb575d3202 100644
> --- a/libstdc++-v3/acinclude.m4
> +++ b/libstdc++-v3/acinclude.m4
> @@ -81,6 +81,10 @@ AC_DEFUN([GLIBCXX_CONFIGURE], [
> AC_HELP_STRING([--with-newlib],
> [assume newlib as a system C library]))
>
> + AC_ARG_WITH([picolibc],
> + AC_HELP_STRING([--with-picolibc],
> + [assume picolibc as a system C library]))
> +
> # Will set LN_S to either 'ln -s', 'ln', or 'cp -p' (if linking isn't
> # available). Uncomment the next line to force a particular method.
> AC_PROG_LN_S
> diff --git a/libstdc++-v3/config/os/picolibc/ctype_base.h b/libstdc++-v3/config/os/picolibc/ctype_base.h
> new file mode 100644
> index 00000000000..bcc9e8df4a3
> --- /dev/null
> +++ b/libstdc++-v3/config/os/picolibc/ctype_base.h
> @@ -0,0 +1,61 @@
> +// Locale support for picolibc -*- C++ -*-
> +
> +// Copyright (C) 2000-2026 Free Software Foundation, Inc.
> +//
> +// This file is part of the GNU ISO C++ Library. This library is free
> +// software; you can redistribute it and/or modify it under the
> +// terms of the GNU General Public License as published by the
> +// Free Software Foundation; either version 3, or (at your option)
> +// any later version.
> +
> +// This library is distributed in the hope that it will be useful,
> +// but WITHOUT ANY WARRANTY; without even the implied warranty of
> +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> +// GNU General Public License for more details.
> +
> +// Under Section 7 of GPL version 3, you are granted additional
> +// permissions described in the GCC Runtime Library Exception, version
> +// 3.1, as published by the Free Software Foundation.
> +
> +// You should have received a copy of the GNU General Public License and
> +// a copy of the GCC Runtime Library Exception along with this program;
> +// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
> +// <http://www.gnu.org/licenses/>.
> +
> +//
> +// ISO C++ 14882: 22.1 Locales
> +//
> +
> +// Information as gleaned from /usr/include/ctype.h
> +
> +namespace std _GLIBCXX_VISIBILITY(default)
> +{
> +_GLIBCXX_BEGIN_NAMESPACE_VERSION
> +
> + /// @brief Base class for ctype.
> + struct ctype_base
> + {
> + // Non-standard typedefs.
> + typedef const int* __to_type;
> +
> + // NB: Offsets into ctype<char>::_M_table force a particular size
> + // on the mask type. Because of this, we don't use an enum.
> + typedef short mask;
> + static const mask upper = mask (__CTYPE_UPPER);
> + static const mask lower = mask (__CTYPE_LOWER);
> + static const mask alpha = mask (__CTYPE_UPPER | __CTYPE_LOWER);
> + static const mask digit = mask (__CTYPE_DIGIT);
> + static const mask xdigit = mask (__CTYPE_HEX | __CTYPE_DIGIT);
> + static const mask space = mask (__CTYPE_SPACE);
> + static const mask print = mask (__CTYPE_PUNCT | __CTYPE_UPPER | __CTYPE_LOWER | __CTYPE_DIGIT | __CTYPE_BLANK);
> + static const mask graph = mask (__CTYPE_PUNCT | __CTYPE_UPPER | __CTYPE_LOWER | __CTYPE_DIGIT);
> + static const mask cntrl = mask (__CTYPE_CNTRL);
> + static const mask punct = mask (__CTYPE_PUNCT);
> + static const mask alnum = mask (__CTYPE_UPPER | __CTYPE_LOWER | __CTYPE_DIGIT);
> +#if __cplusplus >= 201103L
> + static const mask blank = mask (__CTYPE_BLANK | __CTYPE_TAB);
> +#endif
> + };
> +
> +_GLIBCXX_END_NAMESPACE_VERSION
> +} // namespace
> diff --git a/libstdc++-v3/config/os/picolibc/ctype_configure_char.cc b/libstdc++-v3/config/os/picolibc/ctype_configure_char.cc
> new file mode 100644
> index 00000000000..7b38fac2422
> --- /dev/null
> +++ b/libstdc++-v3/config/os/picolibc/ctype_configure_char.cc
> @@ -0,0 +1,105 @@
> +// Locale support for picolibc -*- C++ -*-
> +
> +// Copyright (C) 2011-2026 Free Software Foundation, Inc.
> +//
> +// This file is part of the GNU ISO C++ Library. This library is free
> +// software; you can redistribute it and/or modify it under the
> +// terms of the GNU General Public License as published by the
> +// Free Software Foundation; either version 3, or (at your option)
> +// any later version.
> +
> +// This library is distributed in the hope that it will be useful,
> +// but WITHOUT ANY WARRANTY; without even the implied warranty of
> +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> +// GNU General Public License for more details.
> +
> +// Under Section 7 of GPL version 3, you are granted additional
> +// permissions described in the GCC Runtime Library Exception, version
> +// 3.1, as published by the Free Software Foundation.
> +
> +// You should have received a copy of the GNU General Public License and
> +// a copy of the GCC Runtime Library Exception along with this program;
> +// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
> +// <http://www.gnu.org/licenses/>.
> +
> +/** @file ctype_configure_char.cc */
> +
> +//
> +// ISO C++ 14882: 22.1 Locales
> +//
> +
> +#include <locale>
> +#include <cstdlib>
> +#include <cstring>
> +
> +namespace std _GLIBCXX_VISIBILITY(default)
> +{
> +_GLIBCXX_BEGIN_NAMESPACE_VERSION
> +
> +// Information as gleaned from /usr/include/ctype.h
> +
> + const ctype_base::mask*
> + ctype<char>::classic_table() throw()
> + { return _ctype_wide + 1; }
> +
> + ctype<char>::ctype(__c_locale, const mask* __table, bool __del,
> + size_t __refs)
> + : facet(__refs), _M_del(__table != 0 && __del),
> + _M_toupper(NULL), _M_tolower(NULL),
> + _M_table(__table ? __table : classic_table())
> + {
> + memset(_M_widen, 0, sizeof(_M_widen));
> + _M_widen_ok = 0;
> + memset(_M_narrow, 0, sizeof(_M_narrow));
> + _M_narrow_ok = 0;
> + }
> +
> + ctype<char>::ctype(const mask* __table, bool __del, size_t __refs)
> + : facet(__refs), _M_del(__table != 0 && __del),
> + _M_toupper(NULL), _M_tolower(NULL),
> + _M_table(__table ? __table : classic_table())
> + {
> + memset(_M_widen, 0, sizeof(_M_widen));
> + _M_widen_ok = 0;
> + memset(_M_narrow, 0, sizeof(_M_narrow));
> + _M_narrow_ok = 0;
> + }
> +
> + char
> + ctype<char>::do_toupper(char __c) const
> + {
> + int __x = __c;
> + return (this->is(ctype_base::lower, __c) ? (__x - 'a' + 'A') : __x);
> + }
> +
> + const char*
> + ctype<char>::do_toupper(char* __low, const char* __high) const
> + {
> + while (__low < __high)
> + {
> + *__low = this->do_toupper(*__low);
> + ++__low;
> + }
> + return __high;
> + }
> +
> + char
> + ctype<char>::do_tolower(char __c) const
> + {
> + int __x = __c;
> + return (this->is(ctype_base::upper, __c) ? (__x - 'A' + 'a') : __x);
> + }
> +
> + const char*
> + ctype<char>::do_tolower(char* __low, const char* __high) const
> + {
> + while (__low < __high)
> + {
> + *__low = this->do_tolower(*__low);
> + ++__low;
> + }
> + return __high;
> + }
> +
> +_GLIBCXX_END_NAMESPACE_VERSION
> +} // namespace
> diff --git a/libstdc++-v3/config/os/picolibc/ctype_inline.h b/libstdc++-v3/config/os/picolibc/ctype_inline.h
> new file mode 100644
> index 00000000000..7903214883b
> --- /dev/null
> +++ b/libstdc++-v3/config/os/picolibc/ctype_inline.h
> @@ -0,0 +1,74 @@
> +// Locale support for picolibc -*- C++ -*-
> +
> +// Copyright (C) 2000-2026 Free Software Foundation, Inc.
> +//
> +// This file is part of the GNU ISO C++ Library. This library is free
> +// software; you can redistribute it and/or modify it under the
> +// terms of the GNU General Public License as published by the
> +// Free Software Foundation; either version 3, or (at your option)
> +// any later version.
> +
> +// This library is distributed in the hope that it will be useful,
> +// but WITHOUT ANY WARRANTY; without even the implied warranty of
> +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> +// GNU General Public License for more details.
> +
> +// Under Section 7 of GPL version 3, you are granted additional
> +// permissions described in the GCC Runtime Library Exception, version
> +// 3.1, as published by the Free Software Foundation.
> +
> +// You should have received a copy of the GNU General Public License and
> +// a copy of the GCC Runtime Library Exception along with this program;
> +// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
> +// <http://www.gnu.org/licenses/>.
> +
> +/** @file bits/ctype_inline.h
> + * This is an internal header file, included by other library headers.
> + * Do not attempt to use it directly. @headername{locale}
> + */
> +
> +//
> +// ISO C++ 14882: 22.1 Locales
> +//
> +
> +// ctype bits to be inlined go here. Non-inlinable (ie virtual do_*)
> +// functions go in ctype.cc
> +
> +namespace std _GLIBCXX_VISIBILITY(default)
> +{
> +_GLIBCXX_BEGIN_NAMESPACE_VERSION
> +
> + bool
> + ctype<char>::
> + is(mask __m, char __c) const
> + { return _M_table[static_cast<unsigned char>(__c)] & __m; }
> +
> + const char*
> + ctype<char>::
> + is(const char* __low, const char* __high, mask* __vec) const
> + {
> + while (__low < __high)
> + *__vec++ = _M_table[static_cast<unsigned char>(*__low++)];
> + return __high;
> + }
> +
> + const char*
> + ctype<char>::
> + scan_is(mask __m, const char* __low, const char* __high) const
> + {
> + while (__low < __high && !this->is(__m, *__low))
> + ++__low;
> + return __low;
> + }
> +
> + const char*
> + ctype<char>::
> + scan_not(mask __m, const char* __low, const char* __high) const
> + {
> + while (__low < __high && this->is(__m, *__low) != 0)
> + ++__low;
> + return __low;
> + }
> +
> +_GLIBCXX_END_NAMESPACE_VERSION
> +} // namespace
> diff --git a/libstdc++-v3/config/os/picolibc/os_defines.h b/libstdc++-v3/config/os/picolibc/os_defines.h
> new file mode 100644
> index 00000000000..e9c611b4fb5
> --- /dev/null
> +++ b/libstdc++-v3/config/os/picolibc/os_defines.h
> @@ -0,0 +1,36 @@
> +// Specific definitions for picolibc -*- C++ -*-
> +
> +// Copyright (C) 2026 Free Software Foundation, Inc.
> +//
> +// This file is part of the GNU ISO C++ Library. This library is free
> +// software; you can redistribute it and/or modify it under the
> +// terms of the GNU General Public License as published by the
> +// Free Software Foundation; either version 3, or (at your option)
> +// any later version.
> +
> +// This library is distributed in the hope that it will be useful,
> +// but WITHOUT ANY WARRANTY; without even the implied warranty of
> +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> +// GNU General Public License for more details.
> +
> +// Under Section 7 of GPL version 3, you are granted additional
> +// permissions described in the GCC Runtime Library Exception, version
> +// 3.1, as published by the Free Software Foundation.
> +
> +// You should have received a copy of the GNU General Public License and
> +// a copy of the GCC Runtime Library Exception along with this program;
> +// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
> +// <http://www.gnu.org/licenses/>.
> +
> +/** @file bits/os_defines.h
> + * This is an internal header file, included by other library headers.
> + * Do not attempt to use it directly. @headername{iosfwd}
> + */
> +
> +#ifndef _GLIBCXX_OS_DEFINES
> +#define _GLIBCXX_OS_DEFINES 1
> +
> +// System-specific #define, typedefs, corrections, etc, go here. This
> +// file will come before all others.
> +
> +#endif
> diff --git a/libstdc++-v3/configure.ac b/libstdc++-v3/configure.ac
> index 339e7bb17a4..cd038ee85ac 100644
> --- a/libstdc++-v3/configure.ac
> +++ b/libstdc++-v3/configure.ac
> @@ -100,6 +100,7 @@ GLIBCXX_CONFIGURE
>
> # Libtool setup.
> if test "x${with_newlib}" != "xyes" &&
> + test "x${with_picolibc}" != "xyes" &&
> test "x${with_avrlibc}" != "xyes" &&
> test "x$with_headers" != "xno"; then
> AC_LIBTOOL_DLOPEN
> @@ -428,6 +429,67 @@ dnl # rather than hardcoding that information.
> glibcxx_cv_mkdir=yes
> ;;
> esac
> + elif test "x${with_picolibc}" = "xyes"; then
> + os_include_dir="os/picolibc"
> + AC_DEFINE(HAVE_HYPOT)
> +
> + # GLIBCXX_CHECK_STDLIB_SUPPORT
> + AC_DEFINE(HAVE_STRTOF)
> +
> + AC_DEFINE(HAVE_ACOSF)
> + AC_DEFINE(HAVE_ASINF)
> + AC_DEFINE(HAVE_ATAN2F)
> + AC_DEFINE(HAVE_ATANF)
> + AC_DEFINE(HAVE_CEILF)
> + AC_DEFINE(HAVE_COSF)
> + AC_DEFINE(HAVE_COSHF)
> + AC_DEFINE(HAVE_EXPF)
> + AC_DEFINE(HAVE_FABSF)
> + AC_DEFINE(HAVE_FLOORF)
> + AC_DEFINE(HAVE_FMODF)
> + AC_DEFINE(HAVE_FREXPF)
> + AC_DEFINE(HAVE_HYPOTF)
> + AC_DEFINE(HAVE_LDEXPF)
> + AC_DEFINE(HAVE_LOG10F)
> + AC_DEFINE(HAVE_LOGF)
> + AC_DEFINE(HAVE_MODFF)
> + AC_DEFINE(HAVE_POWF)
> + AC_DEFINE(HAVE_SINF)
> + AC_DEFINE(HAVE_SINHF)
> + AC_DEFINE(HAVE_SQRTF)
> + AC_DEFINE(HAVE_TANF)
> + AC_DEFINE(HAVE_TANHF)
> +
> + # Support for iconv in picolibc is configurable.
> + AC_TRY_COMPILE([#include <picolibc.h>], [
> + #ifndef _ICONV_ENABLED
> + #error
> + #endif], [ac_picolibc_iconv_enabled=yes], [ac_picolibc_iconv_enabled=no])
> + if test "$ac_picolibc_iconv_enabled" = yes; then
> + AC_DEFINE(HAVE_ICONV)
> + fi
> +
> + AC_DEFINE(HAVE_MEMALIGN)
> +
> + # Check for TLS
> + AC_TRY_COMPILE([#include <picolibc.h>], [
> + #ifndef __THREAD_LOCAL_STORAGE
> + #error
> + #endif], [ac_picolibc_tls_enabled=yes], [ac_picolibc_tls_enabled=no])
> + if test "$ac_picolibc_tls_enabled" = yes; then
> + AC_DEFINE(HAVE_TLS)
> + fi
> +
> + AC_DEFINE(HAVE_ALIGNED_ALLOC)
> + AC_DEFINE(HAVE_AT_QUICK_EXIT)
> + AC_DEFINE(HAVE_LINK)
> + AC_DEFINE(HAVE_SYS_STAT_H)
> + AC_DEFINE(HAVE_SYS_TYPES_H)
> + AC_DEFINE(HAVE_SETENV)
> + AC_DEFINE(HAVE_STRERROR_L)
> + AC_DEFINE(HAVE_S_ISREG)
> + AC_DEFINE(HAVE_UNISTD_H)
> +
> elif test "x$with_headers" != "xno"; then
> GLIBCXX_CROSSCONFIG
> fi
> --
> 2.51.0
>
@@ -81,6 +81,10 @@ AC_DEFUN([GLIBCXX_CONFIGURE], [
AC_HELP_STRING([--with-newlib],
[assume newlib as a system C library]))
+ AC_ARG_WITH([picolibc],
+ AC_HELP_STRING([--with-picolibc],
+ [assume picolibc as a system C library]))
+
# Will set LN_S to either 'ln -s', 'ln', or 'cp -p' (if linking isn't
# available). Uncomment the next line to force a particular method.
AC_PROG_LN_S
new file mode 100644
@@ -0,0 +1,61 @@
+// Locale support for picolibc -*- C++ -*-
+
+// Copyright (C) 2000-2026 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
+
+//
+// ISO C++ 14882: 22.1 Locales
+//
+
+// Information as gleaned from /usr/include/ctype.h
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+ /// @brief Base class for ctype.
+ struct ctype_base
+ {
+ // Non-standard typedefs.
+ typedef const int* __to_type;
+
+ // NB: Offsets into ctype<char>::_M_table force a particular size
+ // on the mask type. Because of this, we don't use an enum.
+ typedef short mask;
+ static const mask upper = mask (__CTYPE_UPPER);
+ static const mask lower = mask (__CTYPE_LOWER);
+ static const mask alpha = mask (__CTYPE_UPPER | __CTYPE_LOWER);
+ static const mask digit = mask (__CTYPE_DIGIT);
+ static const mask xdigit = mask (__CTYPE_HEX | __CTYPE_DIGIT);
+ static const mask space = mask (__CTYPE_SPACE);
+ static const mask print = mask (__CTYPE_PUNCT | __CTYPE_UPPER | __CTYPE_LOWER | __CTYPE_DIGIT | __CTYPE_BLANK);
+ static const mask graph = mask (__CTYPE_PUNCT | __CTYPE_UPPER | __CTYPE_LOWER | __CTYPE_DIGIT);
+ static const mask cntrl = mask (__CTYPE_CNTRL);
+ static const mask punct = mask (__CTYPE_PUNCT);
+ static const mask alnum = mask (__CTYPE_UPPER | __CTYPE_LOWER | __CTYPE_DIGIT);
+#if __cplusplus >= 201103L
+ static const mask blank = mask (__CTYPE_BLANK | __CTYPE_TAB);
+#endif
+ };
+
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace
new file mode 100644
@@ -0,0 +1,105 @@
+// Locale support for picolibc -*- C++ -*-
+
+// Copyright (C) 2011-2026 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
+
+/** @file ctype_configure_char.cc */
+
+//
+// ISO C++ 14882: 22.1 Locales
+//
+
+#include <locale>
+#include <cstdlib>
+#include <cstring>
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+// Information as gleaned from /usr/include/ctype.h
+
+ const ctype_base::mask*
+ ctype<char>::classic_table() throw()
+ { return _ctype_wide + 1; }
+
+ ctype<char>::ctype(__c_locale, const mask* __table, bool __del,
+ size_t __refs)
+ : facet(__refs), _M_del(__table != 0 && __del),
+ _M_toupper(NULL), _M_tolower(NULL),
+ _M_table(__table ? __table : classic_table())
+ {
+ memset(_M_widen, 0, sizeof(_M_widen));
+ _M_widen_ok = 0;
+ memset(_M_narrow, 0, sizeof(_M_narrow));
+ _M_narrow_ok = 0;
+ }
+
+ ctype<char>::ctype(const mask* __table, bool __del, size_t __refs)
+ : facet(__refs), _M_del(__table != 0 && __del),
+ _M_toupper(NULL), _M_tolower(NULL),
+ _M_table(__table ? __table : classic_table())
+ {
+ memset(_M_widen, 0, sizeof(_M_widen));
+ _M_widen_ok = 0;
+ memset(_M_narrow, 0, sizeof(_M_narrow));
+ _M_narrow_ok = 0;
+ }
+
+ char
+ ctype<char>::do_toupper(char __c) const
+ {
+ int __x = __c;
+ return (this->is(ctype_base::lower, __c) ? (__x - 'a' + 'A') : __x);
+ }
+
+ const char*
+ ctype<char>::do_toupper(char* __low, const char* __high) const
+ {
+ while (__low < __high)
+ {
+ *__low = this->do_toupper(*__low);
+ ++__low;
+ }
+ return __high;
+ }
+
+ char
+ ctype<char>::do_tolower(char __c) const
+ {
+ int __x = __c;
+ return (this->is(ctype_base::upper, __c) ? (__x - 'A' + 'a') : __x);
+ }
+
+ const char*
+ ctype<char>::do_tolower(char* __low, const char* __high) const
+ {
+ while (__low < __high)
+ {
+ *__low = this->do_tolower(*__low);
+ ++__low;
+ }
+ return __high;
+ }
+
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace
new file mode 100644
@@ -0,0 +1,74 @@
+// Locale support for picolibc -*- C++ -*-
+
+// Copyright (C) 2000-2026 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
+
+/** @file bits/ctype_inline.h
+ * This is an internal header file, included by other library headers.
+ * Do not attempt to use it directly. @headername{locale}
+ */
+
+//
+// ISO C++ 14882: 22.1 Locales
+//
+
+// ctype bits to be inlined go here. Non-inlinable (ie virtual do_*)
+// functions go in ctype.cc
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+ bool
+ ctype<char>::
+ is(mask __m, char __c) const
+ { return _M_table[static_cast<unsigned char>(__c)] & __m; }
+
+ const char*
+ ctype<char>::
+ is(const char* __low, const char* __high, mask* __vec) const
+ {
+ while (__low < __high)
+ *__vec++ = _M_table[static_cast<unsigned char>(*__low++)];
+ return __high;
+ }
+
+ const char*
+ ctype<char>::
+ scan_is(mask __m, const char* __low, const char* __high) const
+ {
+ while (__low < __high && !this->is(__m, *__low))
+ ++__low;
+ return __low;
+ }
+
+ const char*
+ ctype<char>::
+ scan_not(mask __m, const char* __low, const char* __high) const
+ {
+ while (__low < __high && this->is(__m, *__low) != 0)
+ ++__low;
+ return __low;
+ }
+
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace
new file mode 100644
@@ -0,0 +1,36 @@
+// Specific definitions for picolibc -*- C++ -*-
+
+// Copyright (C) 2026 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
+
+/** @file bits/os_defines.h
+ * This is an internal header file, included by other library headers.
+ * Do not attempt to use it directly. @headername{iosfwd}
+ */
+
+#ifndef _GLIBCXX_OS_DEFINES
+#define _GLIBCXX_OS_DEFINES 1
+
+// System-specific #define, typedefs, corrections, etc, go here. This
+// file will come before all others.
+
+#endif
@@ -100,6 +100,7 @@ GLIBCXX_CONFIGURE
# Libtool setup.
if test "x${with_newlib}" != "xyes" &&
+ test "x${with_picolibc}" != "xyes" &&
test "x${with_avrlibc}" != "xyes" &&
test "x$with_headers" != "xno"; then
AC_LIBTOOL_DLOPEN
@@ -428,6 +429,67 @@ dnl # rather than hardcoding that information.
glibcxx_cv_mkdir=yes
;;
esac
+ elif test "x${with_picolibc}" = "xyes"; then
+ os_include_dir="os/picolibc"
+ AC_DEFINE(HAVE_HYPOT)
+
+ # GLIBCXX_CHECK_STDLIB_SUPPORT
+ AC_DEFINE(HAVE_STRTOF)
+
+ AC_DEFINE(HAVE_ACOSF)
+ AC_DEFINE(HAVE_ASINF)
+ AC_DEFINE(HAVE_ATAN2F)
+ AC_DEFINE(HAVE_ATANF)
+ AC_DEFINE(HAVE_CEILF)
+ AC_DEFINE(HAVE_COSF)
+ AC_DEFINE(HAVE_COSHF)
+ AC_DEFINE(HAVE_EXPF)
+ AC_DEFINE(HAVE_FABSF)
+ AC_DEFINE(HAVE_FLOORF)
+ AC_DEFINE(HAVE_FMODF)
+ AC_DEFINE(HAVE_FREXPF)
+ AC_DEFINE(HAVE_HYPOTF)
+ AC_DEFINE(HAVE_LDEXPF)
+ AC_DEFINE(HAVE_LOG10F)
+ AC_DEFINE(HAVE_LOGF)
+ AC_DEFINE(HAVE_MODFF)
+ AC_DEFINE(HAVE_POWF)
+ AC_DEFINE(HAVE_SINF)
+ AC_DEFINE(HAVE_SINHF)
+ AC_DEFINE(HAVE_SQRTF)
+ AC_DEFINE(HAVE_TANF)
+ AC_DEFINE(HAVE_TANHF)
+
+ # Support for iconv in picolibc is configurable.
+ AC_TRY_COMPILE([#include <picolibc.h>], [
+ #ifndef _ICONV_ENABLED
+ #error
+ #endif], [ac_picolibc_iconv_enabled=yes], [ac_picolibc_iconv_enabled=no])
+ if test "$ac_picolibc_iconv_enabled" = yes; then
+ AC_DEFINE(HAVE_ICONV)
+ fi
+
+ AC_DEFINE(HAVE_MEMALIGN)
+
+ # Check for TLS
+ AC_TRY_COMPILE([#include <picolibc.h>], [
+ #ifndef __THREAD_LOCAL_STORAGE
+ #error
+ #endif], [ac_picolibc_tls_enabled=yes], [ac_picolibc_tls_enabled=no])
+ if test "$ac_picolibc_tls_enabled" = yes; then
+ AC_DEFINE(HAVE_TLS)
+ fi
+
+ AC_DEFINE(HAVE_ALIGNED_ALLOC)
+ AC_DEFINE(HAVE_AT_QUICK_EXIT)
+ AC_DEFINE(HAVE_LINK)
+ AC_DEFINE(HAVE_SYS_STAT_H)
+ AC_DEFINE(HAVE_SYS_TYPES_H)
+ AC_DEFINE(HAVE_SETENV)
+ AC_DEFINE(HAVE_STRERROR_L)
+ AC_DEFINE(HAVE_S_ISREG)
+ AC_DEFINE(HAVE_UNISTD_H)
+
elif test "x$with_headers" != "xno"; then
GLIBCXX_CROSSCONFIG
fi