| /* Get register location expression for frame. |
| Copyright (C) 2009 Red Hat, Inc. |
| This file is part of Red Hat elfutils. |
| |
| Red Hat elfutils is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by the |
| Free Software Foundation; version 2 of the License. |
| |
| Red Hat elfutils is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License along |
| with Red Hat elfutils; if not, write to the Free Software Foundation, |
| Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. |
| |
| In addition, as a special exception, Red Hat, Inc. gives You the |
| additional right to link the code of Red Hat elfutils with code licensed |
| under any Open Source Initiative certified open source license |
| (http://www.opensource.org/licenses/index.php) which requires the |
| distribution of source code with any binary distribution and to |
| distribute linked combinations of the two. Non-GPL Code permitted under |
| this exception must only link to the code of Red Hat elfutils through |
| those well defined interfaces identified in the file named EXCEPTION |
| found in the source code files (the "Approved Interfaces"). The files |
| of Non-GPL Code may instantiate templates or use macros or inline |
| functions from the Approved Interfaces without causing the resulting |
| work to be covered by the GNU General Public License. Only Red Hat, |
| Inc. may make changes or additions to the list of Approved Interfaces. |
| Red Hat's grant of this exception is conditioned upon your not adding |
| any new exceptions. If you wish to add a new Approved Interface or |
| exception, please contact Red Hat. You must obey the GNU General Public |
| License in all respects for all of the Red Hat elfutils code and other |
| code used in conjunction with Red Hat elfutils except the Non-GPL Code |
| covered by this exception. If you modify this file, you may extend this |
| exception to your version of the file, but you are not obligated to do |
| so. If you do not wish to provide this exception without modification, |
| you must delete this exception statement from your version and license |
| this file solely under the GPL without exception. |
| |
| Red Hat elfutils is an included package of the Open Invention Network. |
| An included package of the Open Invention Network is a package for which |
| Open Invention Network licensees cross-license their patents. No patent |
| license is granted, either expressly or impliedly, by designation as an |
| included package. Should you wish to participate in the Open Invention |
| Network licensing program, please visit www.openinventionnetwork.com |
| <http://www.openinventionnetwork.com>. */ |
| |
| #ifdef HAVE_CONFIG_H |
| # include <config.h> |
| #endif |
| |
| #include "cfi.h" |
| #include <dwarf.h> |
| |
| int |
| dwarf_frame_register (fs, regno, ops_mem, ops, nops) |
| Dwarf_Frame *fs; |
| int regno; |
| Dwarf_Op ops_mem[3]; |
| Dwarf_Op **ops; |
| size_t *nops; |
| { |
| /* Maybe there was a previous error. */ |
| if (fs == NULL) |
| return -1; |
| |
| if (unlikely (regno < 0)) |
| { |
| __libdw_seterrno (DWARF_E_INVALID_ACCESS); |
| return -1; |
| } |
| |
| *ops = ops_mem; |
| *nops = 0; |
| |
| if (unlikely ((size_t) regno >= fs->nregs)) |
| goto default_rule; |
| |
| const struct dwarf_frame_register *reg = &fs->regs[regno]; |
| |
| switch (reg->rule) |
| { |
| case reg_unspecified: |
| default_rule: |
| /* Use the default rule for registers not yet mentioned in CFI. */ |
| if (fs->cache->default_same_value) |
| goto same_value; |
| /*FALLTHROUGH*/ |
| case reg_undefined: |
| /* The value is known to be unavailable. */ |
| break; |
| |
| case reg_same_value: |
| same_value: |
| /* The location is not known here, but the caller might know it. */ |
| *ops = NULL; |
| break; |
| |
| case reg_offset: |
| case reg_val_offset: |
| ops_mem[(*nops)++] = (Dwarf_Op) { .atom = DW_OP_call_frame_cfa }; |
| if (reg->value != 0) |
| ops_mem[(*nops)++] = (Dwarf_Op) { .atom = DW_OP_plus_uconst, |
| .number = reg->value }; |
| if (reg->rule == reg_val_offset) |
| /* A value, not a location. */ |
| ops_mem[(*nops)++] = (Dwarf_Op) { .atom = DW_OP_stack_value }; |
| *ops = ops_mem; |
| break; |
| |
| case reg_register: |
| ops_mem[(*nops)++] = (Dwarf_Op) { .atom = DW_OP_regx, |
| .number = reg->value }; |
| break; |
| |
| case reg_val_expression: |
| case reg_expression: |
| { |
| unsigned int address_size = (fs->cache->e_ident[EI_CLASS] == ELFCLASS32 |
| ? 4 : 8); |
| |
| Dwarf_Block block; |
| const uint8_t *p = fs->cache->data->d.d_buf + reg->value; |
| get_uleb128 (block.length, p); |
| block.data = (void *) p; |
| |
| /* Parse the expression into internal form. */ |
| if (__libdw_intern_expression (NULL, |
| fs->cache->other_byte_order, |
| address_size, |
| &fs->cache->expr_tree, &block, |
| reg->rule == reg_val_expression, |
| ops, nops, IDX_debug_frame) < 0) |
| return -1; |
| break; |
| } |
| } |
| |
| return 0; |
| } |