1 /* Helper functions for form handling.
2 Copyright (C) 2003-2009, 2014 Red Hat, Inc.
3 This file is part of elfutils.
4 Written by Ulrich Drepper <drepper@redhat.com>, 2003.
6 This file is free software; you can redistribute it and/or modify
7 it under the terms of either
9 * the GNU Lesser General Public License as published by the Free
10 Software Foundation; either version 3 of the License, or (at
11 your option) any later version
15 * the GNU General Public License as published by the Free
16 Software Foundation; either version 2 of the License, or (at
17 your option) any later version
19 or both in parallel, as here.
21 elfutils is distributed in the hope that it will be useful, but
22 WITHOUT ANY WARRANTY; without even the implied warranty of
23 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
24 General Public License for more details.
26 You should have received copies of the GNU General Public License and
27 the GNU Lesser General Public License along with this program. If
28 not, see <http://www.gnu.org/licenses/>. */
42 __libdw_form_val_compute_len (struct Dwarf_CU *cu, unsigned int form,
43 const unsigned char *valp)
45 const unsigned char *startp = valp;
46 const unsigned char *endp = cu->endp;
50 /* NB: This doesn't cover constant form lengths, which are
51 already handled by the inlined __libdw_form_val_len. */
55 result = cu->address_size;
58 case DW_FORM_ref_addr:
59 result = cu->version == 2 ? cu->address_size : cu->offset_size;
63 case DW_FORM_strp_sup:
64 case DW_FORM_line_strp:
65 case DW_FORM_sec_offset:
66 case DW_FORM_GNU_ref_alt:
67 case DW_FORM_GNU_strp_alt:
68 result = cu->offset_size;
72 if (unlikely ((size_t) (endp - startp) < 1))
78 if (unlikely ((size_t) (endp - startp) < 2))
80 result = read_2ubyte_unaligned (cu->dbg, valp) + 2;
84 if (unlikely ((size_t) (endp - startp) < 4))
86 result = read_4ubyte_unaligned (cu->dbg, valp) + 4;
91 get_uleb128 (u128, valp, endp);
92 result = u128 + (valp - startp);
97 const unsigned char *endstrp = memchr (valp, '\0',
98 (size_t) (endp - startp));
99 if (unlikely (endstrp == NULL))
101 result = (size_t) (endstrp - startp) + 1;
107 case DW_FORM_ref_udata:
109 case DW_FORM_loclistx:
110 case DW_FORM_rnglistx:
112 case DW_FORM_GNU_addr_index:
113 case DW_FORM_GNU_str_index:
114 get_uleb128 (u128, valp, endp);
115 result = valp - startp;
118 case DW_FORM_indirect:
119 /* The amount of data to skip in the DIE is the size of the actual
120 FORM data (which is __libdw_form_val_len) plus the size of the
121 uleb128 encoding that FORM (which is valp - startp). */
122 get_uleb128 (u128, valp, endp);
123 if (*valp == DW_FORM_indirect || *valp == DW_FORM_implicit_const)
125 result = __libdw_form_val_len (cu, u128, valp);
126 if (result != (size_t) -1)
127 result += valp - startp;
136 if (unlikely (result > (size_t) (endp - startp)))
139 __libdw_seterrno (DWARF_E_INVALID_DWARF);
140 result = (size_t) -1;