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

[Adhemerval Zanella <adhemerval.zanella@linaro.org>]

On 19/01/2021 11:16, Vaseeharan Vinayagamoorthy wrote:
> 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.

Does the following help:

--
diff --git a/posix/regex_internal.h b/posix/regex_internal.h
index e31ac92674..944de219c3 100644
--- a/posix/regex_internal.h
+++ b/posix/regex_internal.h
@@ -849,7 +849,7 @@ re_string_elem_size_at (const re_string_t *pstr, Idx idx)
 #endif /* RE_ENABLE_I18N */
 
 #ifndef FALLTHROUGH
-# if (__GNUC__ >= 7) || (__clang_major__ >= 10)
+# if (__GNUC__ >= 7) || (defined __clang_major__ &&__clang_major__ >= 10)
 #  define FALLTHROUGH __attribute__ ((__fallthrough__))
 # else
 #  define FALLTHROUGH ((void) 0)
--

Paul, this seemed to a common pattern scatter on multiple file in gnulib.
Wouldn't be better to consolidate it on cdefs.h?

> 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
> 
>