1 /* Iterate through the CU units for a given Dwarf.
2    Copyright (C) 2016, 2017 Red Hat, Inc.
3    This file is part of elfutils.
4 
5    This file is free software; you can redistribute it and/or modify
6    it under the terms of either
7 
8      * the GNU Lesser General Public License as published by the Free
9        Software Foundation; either version 3 of the License, or (at
10        your option) any later version
11 
12    or
13 
14      * the GNU General Public License as published by the Free
15        Software Foundation; either version 2 of the License, or (at
16        your option) any later version
17 
18    or both in parallel, as here.
19 
20    elfutils is distributed in the hope that it will be useful, but
21    WITHOUT ANY WARRANTY; without even the implied warranty of
22    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
23    General Public License for more details.
24 
25    You should have received copies of the GNU General Public License and
26    the GNU Lesser General Public License along with this program.  If
27    not, see <http://www.gnu.org/licenses/>.  */
28 
29 
30 #ifdef HAVE_CONFIG_H
31 # include <config.h>
32 #endif
33 
34 #include <string.h>
35 
36 #include "libdwP.h"
37 
38 int
dwarf_get_units(Dwarf * dwarf,Dwarf_CU * cu,Dwarf_CU ** next_cu,Dwarf_Half * version,uint8_t * unit_type,Dwarf_Die * cudie,Dwarf_Die * subdie)39 dwarf_get_units (Dwarf *dwarf, Dwarf_CU *cu, Dwarf_CU **next_cu,
40 		 Dwarf_Half *version, uint8_t *unit_type,
41 		 Dwarf_Die *cudie, Dwarf_Die *subdie)
42 {
43   /* Handle existing error.  */
44   if (dwarf == NULL)
45     return -1;
46 
47   Dwarf_Off off;
48   bool v4type;
49   if (cu == NULL)
50     {
51       off = 0;
52       v4type = false;
53     }
54   else
55     {
56       off = cu->end;
57       v4type = cu->sec_idx != IDX_debug_info;
58 
59       /* Make sure we got a real (not fake) CU.  */
60       if (cu->sec_idx != IDX_debug_info && cu->sec_idx != IDX_debug_types)
61 	{
62 	  __libdw_seterrno (DWARF_E_INVALID_OFFSET);
63 	  return -1;
64 	}
65 
66       /* Do we have to switch to the other section, or are we at the end?  */
67       if (! v4type)
68 	{
69 	  if (off >= cu->dbg->sectiondata[IDX_debug_info]->d_size)
70 	    {
71 	      if (cu->dbg->sectiondata[IDX_debug_types] == NULL)
72 		return 1;
73 
74 	      off = 0;
75 	      v4type = true;
76 	    }
77 	}
78       else
79 	if (off >= cu->dbg->sectiondata[IDX_debug_types]->d_size)
80 	  return 1;
81     }
82 
83   *next_cu = __libdw_findcu (dwarf, off, v4type);
84   if (*next_cu == NULL)
85     return -1;
86 
87   Dwarf_CU *next = (*next_cu);
88 
89   if (version != NULL)
90     *version = next->version;
91 
92   if (unit_type != NULL)
93     *unit_type = next->unit_type;
94 
95   if (cudie != NULL)
96     {
97       if (next->version >= 2 && next->version <= 5
98 	  && next->unit_type >= DW_UT_compile
99 	  && next->unit_type <= DW_UT_split_type)
100 	*cudie = CUDIE (next);
101       else
102 	memset (cudie, '\0', sizeof (Dwarf_Die));
103     }
104 
105   if (subdie != NULL)
106     {
107       if (next->version >= 2 && next->version <= 5)
108 	{
109 	  /* For types, return the actual type DIE.  For skeletons,
110 	     find the associated split compile unit and return its
111 	     DIE.  */
112 	  if (next->unit_type == DW_UT_type
113 	      || next->unit_type == DW_UT_split_type)
114 	    *subdie = SUBDIE(next);
115 	  else if (next->unit_type == DW_UT_skeleton)
116 	    {
117 	      Dwarf_CU *split_cu = __libdw_find_split_unit (next);
118 	      if (split_cu != NULL)
119 		*subdie = CUDIE(split_cu);
120 	      else
121 		memset (subdie, '\0', sizeof (Dwarf_Die));
122 	    }
123 	  else
124 	    memset (subdie, '\0', sizeof (Dwarf_Die));
125 	}
126       else
127 	memset (subdie, '\0', sizeof (Dwarf_Die));
128     }
129 
130   return 0;
131 }
132