Re: [PATCH 1/5] posix: Sync regex code with gnulib

[Vaseeharan Vinayagamoorthy]

After this commit [1], I am seeing  -Werror=undef when bootstapping glibc on 
aarch64-none-linux-gnu :

In file included from regex.c:70:0:
regex_internal.h:852:26: error: "__clang_major__" is not defined [-Werror=undef]
 # if (__GNUC__ >= 7) || (__clang_major__ >= 10)
                          ^~~~~~~~~~~~~~~

The build/host/target setup is:
Build: aarch64-none-linux-gnu (Ubuntu 14.04)
Host: aarch64-none-linux-gnu
Target: aarch64-none-linux-gnu

[1]
commit c2a150d089fa096cb5f9e342da80fb30dc0d1953
Author:     Adhemerval Zanella <adhemerval.zanella@linaro.org>
AuthorDate: Tue Dec 29 17:32:25 2020 -0300
Commit:     Adhemerval Zanella <adhemerval.zanella@linaro.org>
CommitDate: Mon Jan 4 08:38:52 2021 -0300

    posix: Sync regex code with gnulib
    
    It sync with gnulib commit 43ee1a6bf.  The main change is 9682f18e9.
    (which does not have a meaniful description).
    
    Checked on x86_64-linux-gnu.




On 30/12/2020, 20:15, "Libc-alpha on behalf of Adhemerval Zanella via 
Libc-alpha" <libc-alpha-bounces@sourceware.org on behalf of 
libc-alpha@sourceware.org> wrote:

    It sync with gnulib commit 43ee1a6bf.  The main change is 9682f18e9.
    (which does not have a meaniful description).

    Checked on x86_64-linux-gnu.
    ---
     posix/regcomp.c        |  2 +-
     posix/regex.h          | 17 ++++++++++++-----
     posix/regex_internal.c | 19 ++++++++++---------
     posix/regex_internal.h | 16 ++++++++++++----
     4 files changed, 35 insertions(+), 19 deletions(-)

    diff --git a/posix/regcomp.c b/posix/regcomp.c
    index 93bb0a0538..692928b0db 100644
    --- a/posix/regcomp.c
    +++ b/posix/regcomp.c
    @@ -558,7 +558,7 @@ weak_alias (__regerror, regerror)
     static const bitset_t utf8_sb_map =
     {
       /* Set the first 128 bits.  */
    -# if defined __GNUC__ && !defined __STRICT_ANSI__
    +# if (defined __GNUC__ || __clang_major__ >= 4) && !defined __STRICT_ANSI__
       [0 ... 0x80 / BITSET_WORD_BITS - 1] = BITSET_WORD_MAX
     # else
     #  if 4 * BITSET_WORD_BITS < ASCII_CHARS
    diff --git a/posix/regex.h b/posix/regex.h
    index 5fe41c8685..7418e6c76f 100644
    --- a/posix/regex.h
    +++ b/posix/regex.h
    @@ -612,7 +612,9 @@ extern int re_exec (const char *);
        'configure' might #define 'restrict' to those words, so pick a
        different name.  */
     #ifndef _Restrict_
    -# if defined __restrict || 2 < __GNUC__ + (95 <= __GNUC_MINOR__)
    +# if defined __restrict \
    +     || 2 < __GNUC__ + (95 <= __GNUC_MINOR__) \
    +     || __clang_major__ >= 3
     #  define _Restrict_ __restrict
     # elif 199901L <= __STDC_VERSION__ || defined restrict
     #  define _Restrict_ restrict
    @@ -620,13 +622,18 @@ extern int re_exec (const char *);
     #  define _Restrict_
     # endif
     #endif
    -/* For [restrict], use glibc's __restrict_arr if available.
    -   Otherwise, GCC 3.1 (not in C++ mode) and C99 support [restrict].  */
    +/* For the ISO C99 syntax
    +     array_name[restrict]
    +   use glibc's __restrict_arr if available.
    +   Otherwise, GCC 3.1 and clang support this syntax (but not in C++ mode).
    +   Other ISO C99 compilers support it as well.  */
     #ifndef _Restrict_arr_
     # ifdef __restrict_arr
     #  define _Restrict_arr_ __restrict_arr
    -# elif ((199901L <= __STDC_VERSION__ || 3 < __GNUC__ + (1 <= 
__GNUC_MINOR__)) \
    -        && !defined __GNUG__)
    +# elif ((199901L <= __STDC_VERSION__ \
    +         || 3 < __GNUC__ + (1 <= __GNUC_MINOR__) \
    +         || __clang_major__ >= 3) \
    +        && !defined __cplusplus)
     #  define _Restrict_arr_ _Restrict_
     # else
     #  define _Restrict_arr_
    diff --git a/posix/regex_internal.c b/posix/regex_internal.c
    index e1b6b4d5af..ed0a13461b 100644
    --- a/posix/regex_internal.c
    +++ b/posix/regex_internal.c
    @@ -300,18 +300,20 @@ build_wcs_upper_buffer (re_string_t *pstr)
           while (byte_idx < end_idx)
        {
          wchar_t wc;
    +     unsigned char ch = pstr->raw_mbs[pstr->raw_mbs_idx + byte_idx];

    -     if (isascii (pstr->raw_mbs[pstr->raw_mbs_idx + byte_idx])
    -         && mbsinit (&pstr->cur_state))
    +     if (isascii (ch) && mbsinit (&pstr->cur_state))
            {
    -         /* In case of a singlebyte character.  */
    -         pstr->mbs[byte_idx]
    -           = toupper (pstr->raw_mbs[pstr->raw_mbs_idx + byte_idx]);
              /* The next step uses the assumption that wchar_t is encoded
                 ASCII-safe: all ASCII values can be converted like this.  */
    -         pstr->wcs[byte_idx] = (wchar_t) pstr->mbs[byte_idx];
    -         ++byte_idx;
    -         continue;
    +         wchar_t wcu = __towupper (ch);
    +         if (isascii (wcu))
    +           {
    +             pstr->mbs[byte_idx] = wcu;
    +             pstr->wcs[byte_idx] = wcu;
    +             byte_idx++;
    +             continue;
    +           }
            }

          remain_len = end_idx - byte_idx;
    @@ -348,7 +350,6 @@ build_wcs_upper_buffer (re_string_t *pstr)
            {
              /* It is an invalid character, an incomplete character
                 at the end of the string, or '\0'.  Just use the byte.  */
    -         int ch = pstr->raw_mbs[pstr->raw_mbs_idx + byte_idx];
              pstr->mbs[byte_idx] = ch;
              /* And also cast it to wide char.  */
              pstr->wcs[byte_idx++] = (wchar_t) ch;
    diff --git a/posix/regex_internal.h b/posix/regex_internal.h
    index 8c42586c42..4a3cf779bf 100644
    --- a/posix/regex_internal.h
    +++ b/posix/regex_internal.h
    @@ -77,6 +77,14 @@
     # define isblank(ch) ((ch) == ' ' || (ch) == '\t')
     #endif

    +/* regex code assumes isascii has its usual numeric meaning,
    +   even if the portable character set uses EBCDIC encoding,
    +   and even if wint_t is wider than int.  */
    +#ifndef _LIBC
    +# undef isascii
    +# define isascii(c) (((c) & ~0x7f) == 0)
    +#endif
    +
     #ifdef _LIBC
     # ifndef _RE_DEFINE_LOCALE_FUNCTIONS
     #  define _RE_DEFINE_LOCALE_FUNCTIONS 1
    @@ -335,7 +343,7 @@ typedef struct
         Idx idx;                       /* for BACK_REF */
         re_context_type ctx_type;      /* for ANCHOR */
       } opr;
    -#if __GNUC__ >= 2 && !defined __STRICT_ANSI__
    +#if (__GNUC__ >= 2 || defined __clang__) && !defined __STRICT_ANSI__
       re_token_type_t type : 8;
     #else
       re_token_type_t type;
    @@ -841,10 +849,10 @@ re_string_elem_size_at (const re_string_t *pstr, Idx 
idx)
     #endif /* RE_ENABLE_I18N */

     #ifndef FALLTHROUGH
    -# if __GNUC__ < 7
    -#  define FALLTHROUGH ((void) 0)
    -# else
    +# if (__GNUC__ >= 7) || (__clang_major__ >= 10)
     #  define FALLTHROUGH __attribute__ ((__fallthrough__))
    +# else
    +#  define FALLTHROUGH ((void) 0)
     # endif
     #endif

    -- 
    2.25.1