Re: [PATCH] Use non-destructive parsing in pkl_resolve_module

[Jose E. Marchesi]

Hi Tim.

    2020-04-09  Tim Rühsen  <address@hidden>
    
            * lib/pkl.c (pkl_resolve_module): Use non-destructive parsing.

OK for master.
Thanks!

    ---
     ChangeLog |  4 ++++
     lib/pkl.c | 60 ++++++++++++++++++-------------------------------------
     2 files changed, 23 insertions(+), 41 deletions(-)
    
    diff --git a/lib/pkl.c b/lib/pkl.c
    index 8ec65bba..3547255e 100644
    --- a/lib/pkl.c
    +++ b/lib/pkl.c
    @@ -477,9 +477,7 @@ pkl_resolve_module (pkl_compiler compiler,
                         const char *module,
                         int filename_p)
     {
    -  char *filename = alloca (strlen (module) + 3 + 1);
    -  char *module_filename = NULL;
    -  char *load_path = NULL;
    +  const char *load_path;
    
       /* Get the load path from the run-time environment.  */
       {
    @@ -502,53 +500,33 @@ pkl_resolve_module (pkl_compiler compiler,
         load_path = PVM_VAL_STR (val);
       }
    
    -  /* Derive the name of the file containing the module, if needed.  */
    -  strcpy (filename, module);
    -  if (!filename_p)
    -    strcat (filename, ".pk");
    -
       /* Traverse the directories in the load path and try to load the
          requested module.  */
       {
         char *full_filename;
    -    char *saveptr = NULL;
    -    char *path = xstrdup (load_path); /* Modified by strtok.  */
    -    char *dir = strtok_r (path, ":", &saveptr);
    +    const char *ext = filename_p ? "" : ".pk";
    +    const char *s, *e;
    
    -    if (dir)
    +    for (s = load_path, e = s; *e; s = e + 1)
           {
    -        do
    -          {
    -            /* Ignore empty entries.  */
    -            if (*dir == '\0')
    -              continue;
    -
    -            /* Substitute %...% marks.  */
    -            if (STREQ (dir, "%DATADIR%"))
    -              dir = PKGDATADIR;
    -
    -            /* Mount the full path and determine whether the resulting
    -               file is readable.  */
    -            full_filename = alloca (strlen (dir)
    -                                    + 1 /* "/" */ + strlen (filename)
    -                                    + 1);
    -            strcpy (full_filename, dir);
    -            strcat (full_filename, "/");
    -            strcat (full_filename, filename);
    -
    -            if (pk_file_readable (full_filename) == NULL)
    -              {
    -                module_filename = xstrdup (full_filename);
    -                break;
    -              }
    -          }
    -        while ((dir = strtok_r (NULL, ":", &saveptr)) != NULL);
    -      }
    +        /* Ignore empty entries. */
    +        if ((e = strchrnul (s, ':')) == s)
    +          continue;
    +
    +        if (!strncmp (s, "%DATADIR%", e - s))
    +          full_filename = pk_str_concat (PKGDATADIR, s + sizeof 
("%DATADIR%") - 1,
    +                                         "/", module, ext, NULL);
    +        else
    +          asprintf (&full_filename, "%.*s/%s%s", (int) (e - s), s, module, 
ext);
    
    -    free (path);
    +        if (pk_file_readable (full_filename) == NULL)
    +          return full_filename;
    +
    +        free (full_filename);
    +      }
       }
    
    -  return module_filename;
    +  return NULL;
     }
    
     int
    --
    2.26.0