| /* Return descriptor for sibling of die. |
| Copyright (C) 2000, 2001, 2002 Red Hat, Inc. |
| This file is part of Red Hat elfutils. |
| Written by Ulrich Drepper <drepper@redhat.com>, 2000. |
| |
| 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. |
| |
| 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 <dwarf.h> |
| #include <stdlib.h> |
| |
| #include <libdwarfP.h> |
| |
| |
| int |
| dwarf_siblingof (dbg, die, return_sub, error) |
| Dwarf_Debug dbg; |
| Dwarf_Die die; |
| Dwarf_Die *return_sub; |
| Dwarf_Error *error; |
| { |
| Dwarf_Small *die_addr; |
| Dwarf_CU_Info cu; |
| Dwarf_Unsigned u128; |
| Dwarf_Die new_die; |
| |
| if (dbg == NULL) |
| return DW_DLV_ERROR; |
| |
| if (die == NULL) |
| { |
| Dwarf_Unsigned die_offset; |
| |
| /* We are supposed to return the DW_TAG_compile_unit die for the |
| current compile unit. For this to succeed the user must have |
| looked for the compile unit before. */ |
| if (dbg->cu_list_current == NULL) |
| { |
| __libdwarf_error (dbg, error, DW_E_NO_CU); |
| return DW_DLV_ERROR; |
| } |
| |
| cu = dbg->cu_list_current; |
| |
| die_offset = (cu->offset + 2 * cu->offset_size - 4 + sizeof (Dwarf_Half) |
| + cu->offset_size + 1); |
| |
| /* Check whether this is withing the debug section. */ |
| if (die_offset >= dbg->sections[IDX_debug_info].size) |
| return DW_DLV_NO_ENTRY; |
| |
| /* Compute the pointer. */ |
| die_addr = ((Dwarf_Small *) dbg->sections[IDX_debug_info].addr |
| + die_offset); |
| } |
| else |
| { |
| unsigned int level = 0; |
| |
| /* We start from the given die. */ |
| cu = die->cu; |
| |
| /* Address of the given die. */ |
| die_addr = die->addr; |
| |
| /* Search for the beginning of the next die on this level. We |
| must not return the dies for children of the given die. */ |
| do |
| { |
| Dwarf_Abbrev abbrev; |
| Dwarf_Small *attrp; |
| Dwarf_Word attr_name; |
| Dwarf_Word attr_form; |
| |
| /* Get abbrev code. */ |
| get_uleb128 (u128, die_addr); |
| /* And get the abbreviation itself. */ |
| abbrev = __libdwarf_get_abbrev (dbg, cu, u128, error); |
| if (abbrev == NULL) |
| return DW_DLV_ERROR; |
| |
| /* This is where the attributes start. */ |
| attrp = abbrev->attrp; |
| |
| /* Does this abbreviation have children? */ |
| if (abbrev->has_children) |
| ++level; |
| |
| while (1) |
| { |
| /* Are we still in bounds? */ |
| if (attrp >= ((Dwarf_Small *)dbg->sections[IDX_debug_abbrev].addr |
| + dbg->sections[IDX_debug_abbrev].size)) |
| { |
| __libdwarf_error (dbg, error, DW_E_INVALID_DWARF); |
| return DW_DLV_ERROR; |
| } |
| |
| /* Get attribute name and form. |
| |
| XXX We don't check whether this reads beyond the end of |
| the section. */ |
| get_uleb128 (attr_name, attrp); |
| get_uleb128 (attr_form, attrp); |
| |
| /* We can stop if we found the attribute with value zero. */ |
| if (attr_name == 0 && attr_form == 0) |
| break; |
| |
| /* See whether this is an sibling attribute which would help |
| us to skip ahead. */ |
| if (attr_name == DW_AT_sibling) |
| { |
| /* Cool. We just have to decode the parameter and we know |
| the offset. */ |
| Dwarf_Unsigned offset; |
| |
| switch (attr_form) |
| { |
| case DW_FORM_ref1: |
| offset = *die_addr; |
| break; |
| |
| case DW_FORM_ref2: |
| offset = read_2ubyte_unaligned (dbg, die_addr); |
| break; |
| |
| case DW_FORM_ref4: |
| offset = read_4ubyte_unaligned (dbg, die_addr); |
| break; |
| |
| case DW_FORM_ref8: |
| offset = read_8ubyte_unaligned (dbg, die_addr); |
| break; |
| |
| case DW_FORM_ref_udata: |
| get_uleb128 (offset, die_addr); |
| break; |
| |
| default: |
| /* The above are all legal forms. Everything else is |
| an error. */ |
| __libdwarf_error (dbg, error, DW_E_INVALID_DWARF); |
| return DW_DLV_ERROR; |
| } |
| |
| /* Compute the new address. Some sanity check first, |
| though. */ |
| if (unlikely (offset > 2 * cu->offset_size - 4 + cu->length)) |
| { |
| __libdwarf_error (dbg, error, DW_E_INVALID_DWARF); |
| return DW_DLV_ERROR; |
| } |
| |
| die_addr = |
| ((Dwarf_Small *) dbg->sections[IDX_debug_info].addr |
| + cu->offset + offset); |
| |
| /* Even if the abbreviation has children we have stepped |
| over them now. */ |
| if (abbrev->has_children) |
| --level; |
| break; |
| } |
| |
| /* Skip over the rest of this attribute (if there is any). */ |
| if (attr_form != 0) |
| { |
| size_t len; |
| |
| if (unlikely (__libdwarf_form_val_len (dbg, cu, attr_form, |
| die_addr, &len, error) |
| != DW_DLV_OK)) |
| return DW_DLV_ERROR; |
| |
| die_addr += len; |
| } |
| } |
| |
| /* Check that we are not yet at the end. */ |
| if (*die_addr == 0) |
| { |
| if (level == 0) |
| return DW_DLV_NO_ENTRY; |
| |
| do |
| ++die_addr; |
| while (--level > 0 && *die_addr == 0); |
| } |
| } |
| while (level > 0); |
| } |
| |
| /* Are we at the end. */ |
| if (die != NULL |
| && die_addr >= ((Dwarf_Small *) dbg->sections[IDX_debug_info].addr |
| + cu->offset + cu->length + 2 * cu->offset_size - 4)) |
| return DW_DLV_NO_ENTRY; |
| |
| /* See whether there is another sibling available or whether this is |
| the end. */ |
| if (*die_addr == 0) |
| return DW_DLV_NO_ENTRY; |
| |
| /* There is more data. Create the data structure. */ |
| new_die = (Dwarf_Die) malloc (sizeof (struct Dwarf_Die_s)); |
| if (new_die == NULL) |
| { |
| __libdwarf_error (dbg, error, DW_E_NOMEM); |
| return DW_DLV_ERROR; |
| } |
| |
| #ifdef DWARF_DEBUG |
| new_die->memtag = DW_DLA_DIE; |
| #endif |
| |
| /* Remember the address. */ |
| new_die->addr = die_addr; |
| |
| /* And the compile unit. */ |
| new_die->cu = cu; |
| |
| /* 7.5.2 Debugging Information Entry |
| |
| Each debugging information entry begins with an unsigned LEB128 |
| number containing the abbreviation code for the entry. */ |
| get_uleb128 (u128, die_addr); |
| |
| /* Find the abbreviation. */ |
| new_die->abbrev = __libdwarf_get_abbrev (dbg, cu, u128, error); |
| if (new_die->abbrev == NULL) |
| { |
| free (new_die); |
| return DW_DLV_ERROR; |
| } |
| |
| /* If we are looking for the first entry this must be a compile unit. */ |
| if (die == NULL && unlikely (new_die->abbrev->tag != DW_TAG_compile_unit)) |
| { |
| free (new_die); |
| __libdwarf_error (dbg, error, DW_E_1ST_NO_CU); |
| return DW_DLV_ERROR; |
| } |
| |
| *return_sub = new_die; |
| return DW_DLV_OK; |
| } |