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