Re: [PATCH] libstdcxx: Update ctype_base.h from NetBSD upstream

[Kamil Rytarowski <n54 at gmx dot com>]

On 07.01.2020 01:28, Jonathan Wakely wrote:
> On 07/01/20 00:18 +0100, Kamil Rytarowski wrote:
>> On 06.01.2020 16:34, Jonathan Wakely wrote:
>>> On 22/12/19 09:36 +1000, Gerald Pfeifer wrote:
>>>> Hi Matthew,
>>>>
>>>> On Mon, 4 Feb 2019, Matthew Bauer wrote:
>>>>> The ctype_base.h file in libstdc++-v3 is out of date for NetBSD. They
>>>>> have changed their ctype.h definition. It was updated in their intree
>>>>> libstdc++-v3 but not in the GCC one. My understanding is this is a
>>>>> straightforward rewrite. I've attached my own patch, but the file can
>>>>> be obtained directly here:
>>>>>
>>>>> http://cvsweb.netbsd.org/bsdweb.cgi/src/external/gpl3/gcc/dist/libstdc%2b%2b-v3/config/os/bsd/netbsd/ctype_base.h
>>>>>
>>>>>
>>>>>
>>>>> With the attached patch, libstdc++-v3 can succesfully be built with
>>>>> NetBSD headers (along with --disable-libcilkrts).
>>>>
>>>> I noticed this has not been applied yet, nor seen a follow-up?, and
>>>> also
>>>> noticed it went to the gcc-patches list, but not libstdc++@gcc.gnu.org.
>>>>
>>>> Let me re-address this to libstdc++@gcc.gnu.org in the hope the
>>>> maintainers there will have a look.
>>>>
>>>> Gerald
>>>
>>>> diff --git a/libstdc++-v3/config/os/bsd/netbsd/ctype_base.h
>>>> b/libstdc++-v3/config/os/bsd/netbsd/ctype_base.h
>>>> index ff3ec893974..21eccf9fde1 100644
>>>> --- a/libstdc++-v3/config/os/bsd/netbsd/ctype_base.h
>>>> +++ b/libstdc++-v3/config/os/bsd/netbsd/ctype_base.h
>>>> @@ -38,40 +38,46 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>>>>   /// @brief  Base class for ctype.
>>>>   struct ctype_base
>>>>   {
>>>> -    // Non-standard typedefs.
>>>> -    typedef const unsigned char*    __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 unsigned char          mask;
>>>>
>>>> #ifndef _CTYPE_U
>>>> -    static const mask upper        = _U;
>>>> -    static const mask lower     = _L;
>>>> -    static const mask alpha     = _U | _L;
>>>> -    static const mask digit     = _N;
>>>> -    static const mask xdigit     = _N | _X;
>>>> -    static const mask space     = _S;
>>>> -    static const mask print     = _P | _U | _L | _N | _B;
>>>> -    static const mask graph     = _P | _U | _L | _N;
>>>> -    static const mask cntrl     = _C;
>>>> -    static const mask punct     = _P;
>>>> -    static const mask alnum     = _U | _L | _N;
>>>> +    // Non-standard typedefs.
>>>> +    typedef const unsigned char*    __to_type;
>>>> +
>>>> +    typedef unsigned char    mask;
>>>> +
>>>> +    static const mask upper    = _U;
>>>> +    static const mask lower    = _L;
>>>> +    static const mask alpha    = _U | _L;
>>>> +    static const mask digit    = _N;
>>>> +    static const mask xdigit    = _N | _X;
>>>> +    static const mask space    = _S;
>>>> +    static const mask print    = _P | _U | _L | _N | _B;
>>>> +    static const mask graph    = _P | _U | _L | _N;
>>>> +    static const mask cntrl    = _C;
>>>> +    static const mask punct    = _P;
>>>> +    static const mask alnum    = _U | _L | _N;
>>>> #else
>>>> -    static const mask upper        = _CTYPE_U;
>>>> -    static const mask lower     = _CTYPE_L;
>>>> -    static const mask alpha     = _CTYPE_U | _CTYPE_L;
>>>> -    static const mask digit     = _CTYPE_N;
>>>> -    static const mask xdigit     = _CTYPE_N | _CTYPE_X;
>>>> -    static const mask space     = _CTYPE_S;
>>>> -    static const mask print     = _CTYPE_P | _CTYPE_U | _CTYPE_L |
>>>> _CTYPE_N | _CTYPE_B;
>>>> -    static const mask graph     = _CTYPE_P | _CTYPE_U | _CTYPE_L |
>>>> _CTYPE_N;
>>>> -    static const mask cntrl     = _CTYPE_C;
>>>> -    static const mask punct     = _CTYPE_P;
>>>> -    static const mask alnum     = _CTYPE_U | _CTYPE_L | _CTYPE_N;
>>>> +    typedef const unsigned short*    __to_type;
>>>> +
>>>> +    typedef unsigned short    mask;
>>>> +
>>>> +    static const mask upper    = _CTYPE_U;
>>>> +    static const mask lower    = _CTYPE_L;
>>>> +    static const mask alpha    = _CTYPE_A;
>>>> +    static const mask digit    = _CTYPE_D;
>>>> +    static const mask xdigit    = _CTYPE_X;
>>>> +    static const mask space    = _CTYPE_S;
>>>> +    static const mask print    = _CTYPE_R;
>>>> +    static const mask graph    = _CTYPE_G;
>>>> +    static const mask cntrl    = _CTYPE_C;
>>>> +    static const mask punct    = _CTYPE_P;
>>>> +    static const mask alnum    = _CTYPE_A | _CTYPE_D;
>>>> #endif
>>>> #if __cplusplus >= 201103L
>>>> -    static const mask blank     = space;
>>>> +    static const mask blank    = space;
>>>> #endif
>>>>   };
>>>>
>>>> diff --git a/libstdc++-v3/config/os/bsd/netbsd/ctype_configure_char.cc
>>>> b/libstdc++-v3/config/os/bsd/netbsd/ctype_configure_char.cc
>>>> index ed3b7cd0d6a..33358e8f5d8 100644
>>>> --- a/libstdc++-v3/config/os/bsd/netbsd/ctype_configure_char.cc
>>>> +++ b/libstdc++-v3/config/os/bsd/netbsd/ctype_configure_char.cc
>>>> @@ -38,11 +38,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>>>>
>>>> // Information as gleaned from /usr/include/ctype.h
>>>>
>>>> -  extern "C" const u_int8_t _C_ctype_[];
>>>> -
>>>>   const ctype_base::mask*
>>>>   ctype<char>::classic_table() throw()
>>>> -  { return _C_ctype_ + 1; }
>>>> +  { return _C_ctype_tab_ + 1; }
>>>
>>> The first patch attached to PR 64271 (i.e.
>>> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34254 ) does that
>>> differently. Is it safe to make this change unconditionally?
>>>
>>
>> This file is NetBSD only (at least in theory) and we likely can do the
>> right think without conditional build here.
> 
> Yes, it's NetBSD-specific, but it's used for multiple versions of
> NetBSD.

This change was introduced in 2013 and we do not support such old
snapshots. If GCC wants to support older releases there it would be futile.

> 
> The patch in PR 64271 only uses _C_ctype_tab_+1 when _CTYPE_BL is
> defined, i.e. for newer versions of NetBSD. For older versions, it
> still uses _C_ctype_.
> 
> So my question is whether _C_ctype_tab_+1 does the right thing for all
> versions of NetBSD, or only for newer ones.
> 

The right thing today is to go unconditionally for _C_ctype_tab_ and
abandon _C_ctype_ entirely.

_C_ctype_ was u8 and did not support all inline semantics.

We still keep _C_ctype_ binary compat for the time being (until next
libc major bump), but it will go away in future (no timeline when).

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