Re: [PATCH] _nl_expand_alias: Remove alloca calls

[Adhemerval Zanella <adhemerval dot zanella at linaro dot org>]

On 19/06/2017 13:18, Florian Weimer wrote:
> 2017-06-19  Florian Weimer  <fweimer@redhat.com>
> 
> 	* intl/localealias.c: Remove alloca support.
> 	(read_alias_file): Use asprintf instead of alloca.

I think we can use char_array on this:

[...]
  FILE *fp = NULL;
  struct char_array full_fname;
  if (char_array_init_str (&full_fname, fname)
      || char_array_append_str (&full_fname, "/locale.alias"))
    {
     /* Note the file is opened with cancellation in the I/O functions
        disabled.  */
#ifdef _LIBC
# define ALIAS_MODE "ce"
#else
# define ALIAS_MODE ""
#endif
     fp = fopen (relocate (char_array_str (&full_fname)), "r" ALIAS_MODE);
    }
  char_array_free (&full_fname);
  if (fp == NULL)
    return 0;
[...]

> 
> diff --git a/intl/localealias.c b/intl/localealias.c
> index 9921aa2..36959df 100644
> --- a/intl/localealias.c
> +++ b/intl/localealias.c
> @@ -32,30 +32,8 @@
>  #endif
>  #include <sys/types.h>
>  
> -#ifdef __GNUC__
> -# undef alloca
> -# define alloca __builtin_alloca
> -# define HAVE_ALLOCA 1
> -#else
> -# ifdef _MSC_VER
> -#  include <malloc.h>
> -#  define alloca _alloca
> -# else
> -#  if defined HAVE_ALLOCA_H || defined _LIBC
> -#   include <alloca.h>
> -#  else
> -#   ifdef _AIX
> - #pragma alloca
> -#   else
> -#    ifndef alloca
> -char *alloca ();
> -#    endif
> -#   endif
> -#  endif
> -# endif
> -#endif
> -
>  #include <stdlib.h>
> +#include <stdio.h>
>  #include <string.h>
>  
>  #include "gettextP.h"
> @@ -101,15 +79,6 @@ char *alloca ();
>  # define FGETS(buf, n, fp)	fgets (buf, n, fp)
>  #endif
>  
> -/* For those losing systems which don't have `alloca' we have to add
> -   some additional code emulating it.  */
> -#ifdef HAVE_ALLOCA
> -# define freea(p) /* nothing */
> -#else
> -# define alloca(n) malloc (n)
> -# define freea(p) free (p)
> -#endif
> -
>  #if defined _LIBC_REENTRANT || defined HAVE_DECL_FGETS_UNLOCKED
>  # undef fgets
>  # define fgets(buf, len, s) fgets_unlocked (buf, len, s)
> @@ -218,16 +187,9 @@ read_alias_file (const char *fname, int fname_len)
>    FILE *fp;
>    char *full_fname;
>    size_t added;
> -  static const char aliasfile[] = "/locale.alias";
>  
> -  full_fname = (char *) alloca (fname_len + sizeof aliasfile);
> -#ifdef HAVE_MEMPCPY
> -  mempcpy (mempcpy (full_fname, fname, fname_len),
> -	   aliasfile, sizeof aliasfile);
> -#else
> -  memcpy (full_fname, fname, fname_len);
> -  memcpy (&full_fname[fname_len], aliasfile, sizeof aliasfile);
> -#endif
> +  if (__asprintf (&full_fname, "%s/locale.alias", fname) < 0)
> +    return 0;
>  
>  #ifdef _LIBC
>    /* Note the file is opened with cancellation in the I/O functions
> @@ -236,7 +198,7 @@ read_alias_file (const char *fname, int fname_len)
>  #else
>    fp = fopen (relocate (full_fname), "r");
>  #endif
> -  freea (full_fname);
> +  free (full_fname);
>    if (fp == NULL)
>      return 0;
>  
>