/* Labelled ranges of type IDs.
  Copyright (C) 2019-2024 Free Software Foundation, Inc.

  This file is part of libctf.

  libctf is free software; you can redistribute it and/or modify it under
  the terms of the GNU General Public License as published by the Free
  Software Foundation; either version 3, or (at your option) any later
  version.

  This program is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  See the GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; see the file COPYING.  If not see
  <http://www.gnu.org/licenses/>.  */

#include <ctf-impl.h>
#include <string.h>

static int
extract_label_info (ctf_dict_t *fp, const ctf_lblent_t **ctl,
                   uint32_t *num_labels)
{
 const ctf_header_t *h;

 h = (const ctf_header_t *) fp->ctf_data.cts_data;

 *ctl = (const ctf_lblent_t *) (fp->ctf_buf + h->cth_lbloff);
 *num_labels = (h->cth_objtoff - h->cth_lbloff) / sizeof (ctf_lblent_t);

 return 0;
}

/* Returns the topmost label, or NULL if any errors are encountered.  */

const char *
ctf_label_topmost (ctf_dict_t *fp)
{
 const ctf_lblent_t *ctlp = NULL;
 const char *s;
 uint32_t num_labels = 0;

 if (extract_label_info (fp, &ctlp, &num_labels) < 0)
   return NULL;                                /* errno is set for us.  */

 if (num_labels == 0)
   {
     (void) ctf_set_errno (fp, ECTF_NOLABELDATA);
     return NULL;
   }

 if ((s = ctf_strraw (fp, (ctlp + num_labels - 1)->ctl_label)) == NULL)
   (void) ctf_set_errno (fp, ECTF_CORRUPT);

 return s;
}

/* Iterate over all labels.  We pass the label string and the lblinfo_t struct
  to the specified callback function.  */
int
ctf_label_iter (ctf_dict_t *fp, ctf_label_f *func, void *arg)
{
 const ctf_lblent_t *ctlp = NULL;
 uint32_t i;
 uint32_t num_labels = 0;
 ctf_lblinfo_t linfo;
 const char *lname;
 int rc;

 if (extract_label_info (fp, &ctlp, &num_labels) < 0)
   return -1;                  /* errno is set for us.  */

 if (num_labels == 0)
   return (ctf_set_errno (fp, ECTF_NOLABELDATA));

 for (i = 0; i < num_labels; i++, ctlp++)
   {
     if ((lname = ctf_strraw (fp, ctlp->ctl_label)) == NULL)
       {
         /* Not marked for translation: label code not used yet.  */
         ctf_err_warn (fp, 0, ECTF_CORRUPT,
                       "failed to decode label %u with type %u",
                       ctlp->ctl_label, ctlp->ctl_type);
         return (ctf_set_errno (fp, ECTF_CORRUPT));
       }

     linfo.ctb_type = ctlp->ctl_type;
     if ((rc = func (lname, &linfo, arg)) != 0)
       return rc;
   }

 return 0;
}

typedef struct linfo_cb_arg
{
 const char *lca_name;         /* Label we want to retrieve info for.  */
 ctf_lblinfo_t *lca_info;      /* Where to store the info about the label.  */
} linfo_cb_arg_t;

static int
label_info_cb (const char *lname, const ctf_lblinfo_t *linfo, void *arg)
{
 /* If lname matches the label we are looking for, copy the
   lblinfo_t struct for the caller.  */

 if (strcmp (lname, ((linfo_cb_arg_t *) arg)->lca_name) == 0)
   {
     /* * Allow caller not to allocate storage to test if label exists.  */

     if (((linfo_cb_arg_t *) arg)->lca_info != NULL)
       memcpy (((linfo_cb_arg_t *) arg)->lca_info, linfo,
              sizeof (ctf_lblinfo_t));
     return 1;         /* Indicate we found a match.  */
   }

 return 0;
}

/* Retrieve information about the label with name "lname". */
int
ctf_label_info (ctf_dict_t *fp, const char *lname, ctf_lblinfo_t *linfo)
{
 linfo_cb_arg_t cb_arg;
 int rc;

 cb_arg.lca_name = lname;
 cb_arg.lca_info = linfo;

 if ((rc = ctf_label_iter (fp, label_info_cb, &cb_arg)) < 0)
   return rc;

 if (rc != 1)
   return (ctf_set_errno (fp, ECTF_NOLABEL));

 return 0;
}