Home | History | Annotate | Line # | Download | only in libctf
ctf-labels.c revision 1.1.1.1.2.2 
      1 /* Labelled ranges of type IDs.
      2    Copyright (C) 2019-2020 Free Software Foundation, Inc.
      3 
      4    This file is part of libctf.
      5 
      6    libctf is free software; you can redistribute it and/or modify it under
      7    the terms of the GNU General Public License as published by the Free
      8    Software Foundation; either version 3, or (at your option) any later
      9    version.
     10 
     11    This program is distributed in the hope that it will be useful, but
     12    WITHOUT ANY WARRANTY; without even the implied warranty of
     13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
     14    See the GNU General Public License for more details.
     15 
     16    You should have received a copy of the GNU General Public License
     17    along with this program; see the file COPYING.  If not see
     18    <http://www.gnu.org/licenses/>.  */
     19 
     20 #include <ctf-impl.h>
     21 #include <string.h>
     22 
     23 static int
     24 extract_label_info (ctf_file_t *fp, const ctf_lblent_t **ctl,
     25 		    uint32_t *num_labels)
     26 {
     27   const ctf_header_t *h;
     28 
     29   h = (const ctf_header_t *) fp->ctf_data.cts_data;
     30 
     31   *ctl = (const ctf_lblent_t *) (fp->ctf_buf + h->cth_lbloff);
     32   *num_labels = (h->cth_objtoff - h->cth_lbloff) / sizeof (ctf_lblent_t);
     33 
     34   return 0;
     35 }
     36 
     37 /* Returns the topmost label, or NULL if any errors are encountered.  */
     38 
     39 const char *
     40 ctf_label_topmost (ctf_file_t *fp)
     41 {
     42   const ctf_lblent_t *ctlp = NULL;
     43   const char *s;
     44   uint32_t num_labels = 0;
     45 
     46   if (extract_label_info (fp, &ctlp, &num_labels) < 0)
     47     return NULL;				/* errno is set for us.  */
     48 
     49   if (num_labels == 0)
     50     {
     51       (void) ctf_set_errno (fp, ECTF_NOLABELDATA);
     52       return NULL;
     53     }
     54 
     55   if ((s = ctf_strraw (fp, (ctlp + num_labels - 1)->ctl_label)) == NULL)
     56     (void) ctf_set_errno (fp, ECTF_CORRUPT);
     57 
     58   return s;
     59 }
     60 
     61 /* Iterate over all labels.  We pass the label string and the lblinfo_t struct
     62    to the specified callback function.  */
     63 int
     64 ctf_label_iter (ctf_file_t *fp, ctf_label_f *func, void *arg)
     65 {
     66   const ctf_lblent_t *ctlp = NULL;
     67   uint32_t i;
     68   uint32_t num_labels = 0;
     69   ctf_lblinfo_t linfo;
     70   const char *lname;
     71   int rc;
     72 
     73   if (extract_label_info (fp, &ctlp, &num_labels) < 0)
     74     return -1;			/* errno is set for us.  */
     75 
     76   if (num_labels == 0)
     77     return (ctf_set_errno (fp, ECTF_NOLABELDATA));
     78 
     79   for (i = 0; i < num_labels; i++, ctlp++)
     80     {
     81       if ((lname = ctf_strraw (fp, ctlp->ctl_label)) == NULL)
     82 	{
     83 	  ctf_dprintf ("failed to decode label %u with "
     84 		       "type %u\n", ctlp->ctl_label, ctlp->ctl_type);
     85 	  return (ctf_set_errno (fp, ECTF_CORRUPT));
     86 	}
     87 
     88       linfo.ctb_type = ctlp->ctl_type;
     89       if ((rc = func (lname, &linfo, arg)) != 0)
     90 	return rc;
     91     }
     92 
     93   return 0;
     94 }
     95 
     96 typedef struct linfo_cb_arg
     97 {
     98   const char *lca_name;		/* Label we want to retrieve info for.  */
     99   ctf_lblinfo_t *lca_info;	/* Where to store the info about the label.  */
    100 } linfo_cb_arg_t;
    101 
    102 static int
    103 label_info_cb (const char *lname, const ctf_lblinfo_t *linfo, void *arg)
    104 {
    105   /* If lname matches the label we are looking for, copy the
    106     lblinfo_t struct for the caller.  */
    107 
    108   if (strcmp (lname, ((linfo_cb_arg_t *) arg)->lca_name) == 0)
    109     {
    110       /* * Allow caller not to allocate storage to test if label exists.  */
    111 
    112       if (((linfo_cb_arg_t *) arg)->lca_info != NULL)
    113 	memcpy (((linfo_cb_arg_t *) arg)->lca_info, linfo,
    114 	       sizeof (ctf_lblinfo_t));
    115       return 1;		/* Indicate we found a match.  */
    116     }
    117 
    118   return 0;
    119 }
    120 
    121 /* Retrieve information about the label with name "lname". */
    122 int
    123 ctf_label_info (ctf_file_t *fp, const char *lname, ctf_lblinfo_t *linfo)
    124 {
    125   linfo_cb_arg_t cb_arg;
    126   int rc;
    127 
    128   cb_arg.lca_name = lname;
    129   cb_arg.lca_info = linfo;
    130 
    131   if ((rc = ctf_label_iter (fp, label_info_cb, &cb_arg)) < 0)
    132     return rc;
    133 
    134   if (rc != 1)
    135     return (ctf_set_errno (fp, ECTF_NOLABEL));
    136 
    137   return 0;
    138 }
    139