1 /* Get register location expression for frame.
2 Copyright (C) 2009-2010 Red Hat, Inc.
3 This file is part of elfutils.
5 This file is free software; you can redistribute it and/or modify
6 it under the terms of either
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
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
18 or both in parallel, as here.
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.
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/>. */
37 dwarf_frame_register (fs, regno, ops_mem, ops, nops)
44 /* Maybe there was a previous error. */
48 if (unlikely (regno < 0))
50 __libdw_seterrno (DWARF_E_INVALID_ACCESS);
57 if (unlikely ((size_t) regno >= fs->nregs))
60 const struct dwarf_frame_register *reg = &fs->regs[regno];
66 /* Use the default rule for registers not yet mentioned in CFI. */
67 if (fs->cache->default_same_value)
71 /* The value is known to be unavailable. */
76 /* The location is not known here, but the caller might know it. */
82 ops_mem[(*nops)++] = (Dwarf_Op) { .atom = DW_OP_call_frame_cfa };
84 ops_mem[(*nops)++] = (Dwarf_Op) { .atom = DW_OP_plus_uconst,
85 .number = reg->value };
86 if (reg->rule == reg_val_offset)
87 /* A value, not a location. */
88 ops_mem[(*nops)++] = (Dwarf_Op) { .atom = DW_OP_stack_value };
93 ops_mem[(*nops)++] = (Dwarf_Op) { .atom = DW_OP_regx,
94 .number = reg->value };
97 case reg_val_expression:
100 unsigned int address_size = (fs->cache->e_ident[EI_CLASS] == ELFCLASS32
104 const uint8_t *p = fs->cache->data->d.d_buf + reg->value;
105 get_uleb128 (block.length, p);
106 block.data = (void *) p;
108 /* Parse the expression into internal form. */
109 if (__libdw_intern_expression (NULL,
110 fs->cache->other_byte_order,
112 &fs->cache->expr_tree, &block,
113 true, reg->rule == reg_val_expression,
114 ops, nops, IDX_debug_frame) < 0)