[PATCH 5/5] a68: add import from .m68 file

[Jose E. Marchesi]

Hi Mohammad.

Thanks for the patch.  See some comments below.

> Signed-off-by: Mohammad-Reza Nabipoor <mnabipoor@gnu.org>
>
> gcc/ChangeLog
>
> 	* algol68/a68-imports.cc (a68_find_export_data): Implement
> 	reading from module's .m68 file if available.

Please use gcc/algol68/Changelog, and adjust relative paths accordingly.

> ---
>  gcc/algol68/a68-imports.cc | 50 ++++++++++++++++++++++++++++++++++----
>  1 file changed, 45 insertions(+), 5 deletions(-)
>
> diff --git a/gcc/algol68/a68-imports.cc b/gcc/algol68/a68-imports.cc
> index 9cd6615b7a4..4a92c197610 100644
> --- a/gcc/algol68/a68-imports.cc
> +++ b/gcc/algol68/a68-imports.cc
> @@ -169,15 +169,56 @@ a68_find_export_data (const std::string &filename, int fd, size_t *psize)
>      }
>  
>    char buf[A68_EXPORT_MAGIC_LEN];
> -  ssize_t c = ::read(fd, buf, A68_EXPORT_MAGIC_LEN);
> +  ssize_t c = read (fd, buf, A68_EXPORT_MAGIC_LEN);
>    if (c < A68_EXPORT_MAGIC_LEN)
>      return NULL;
>  
>    /* Check for a file containing nothing but Algol 68 export data.  */
> -  if (buf[0] == '\x0a' && buf[1] == '\xad')
> +  if (buf[0] == '\x0a' && buf[1] == '\x68')
>      {
> -      /* XXX read whole file.  */
> -      return exports;
> +      /* read whole file.  */
> +
> +      char *buf;
> +      off_t len;
> +      ssize_t nread;
> +
> +      len = lseek (fd, 0, SEEK_END);
> +      if (len < 0)
> +        {
> +          a68_error (NO_NODE, "lseek Z failed", filename.c_str ());
> +          return NULL;
> +        }
> +      if (lseek (fd, 0, SEEK_SET) < 0)
> +        {
> +          a68_error (NO_NODE, "lseek Z failed", filename.c_str ());
> +          return NULL;
> +        }
> +
> +      buf = XNEWVEC (char, len);
> +      if (buf == NULL)
> +        {
> +          a68_error (NO_NODE,
> +                     "memory allocation failed while reading export data");
> +          return NULL;
> +        }
> +
> +      nread = read (fd, buf, len);
> +      if (nread < 0)
> +        {
> +          free (buf);
> +          a68_error (NO_NODE, "read failed while reading export data");
> +          return NULL;
> +        }
> +
> +      if (nread < len)
> +        {
> +          free (buf);
> +          a68_error (NO_NODE, "short read while reading export data");
> +          return NULL;
> +        }
> +
> +      *psize = len;
> +      return buf;

I am currently working in implementing -fmodules-map-file=<filename>
and, along with the scanner, that is another place where to read the
full contents of a file in a buffer.  So I am factoring out a function
for that, and I suggest to use it for this as well.

>      }
>  
>  #if 0
> @@ -187,7 +228,6 @@ a68_find_export_data (const std::string &filename, int fd, size_t *psize)
>  #endif
>  
>    return NULL;
> -
>  }
>  
>  /* Given *PFILENAME, where *PFILENAME does not exist, try various suffixes.  If