rpm/elfutils/libdwarf/dwarf_offdie.c

124 lines
3.2 KiB
C

/* Return die at given offset.
Copyright (C) 2000, 2002 Red Hat, Inc.
Written by Ulrich Drepper <drepper@redhat.com>, 2000.
This program is Open Source software; you can redistribute it and/or
modify it under the terms of the Open Software License version 1.0 as
published by the Open Source Initiative.
You should have received a copy of the Open Software License along
with this program; if not, you may obtain a copy of the Open Software
License version 1.0 from http://www.opensource.org/licenses/osl.php or
by writing the Open Source Initiative c/o Lawrence Rosen, Esq.,
3001 King Ranch Road, Ukiah, CA 95482. */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <dwarf.h>
#include <stdlib.h>
#include <libdwarfP.h>
/* XXX This function will have to be optimized. The search is too linear
to be performed too often -> O(n²). */
static Dwarf_CU_Info
find_cu (Dwarf_Debug dbg, Dwarf_Off offset, Dwarf_Error *error)
{
Dwarf_CU_Info cu;
Dwarf_Word cu_offset;
/* Search in the CUs already known. */
for (cu = dbg->cu_list; cu != NULL; cu = cu->next)
if (cu->offset <= offset
&& cu->offset + 2 * cu->offset_size - 4 + cu->length > offset)
return cu;
/* The CU is not yet loaded. Do this now. */
if (dbg->cu_list_tail == NULL)
cu_offset = 0;
else
cu_offset = (dbg->cu_list_tail->offset
+ 2 * dbg->cu_list_tail->offset_size - 4
+ dbg->cu_list_tail->length);
while (1)
{
/* Get next CU and add it to the end of the list. */
if (__libdwarf_get_cu_at_offset (dbg, cu_offset, &cu, error)
!= DW_DLV_OK)
return NULL;
/* Offset of next CU. */
cu_offset += 2 * cu->offset_size - 4 + cu->length;
/* If this the CU we are looking for? */
if (offset < cu_offset)
return cu;
}
}
int
dwarf_offdie (dbg, offset, return_die, error)
Dwarf_Debug dbg;
Dwarf_Off offset;
Dwarf_Die *return_die;
Dwarf_Error *error;
{
Dwarf_CU_Info cu;
Dwarf_Die new_die;
Dwarf_Small *die_addr;
Dwarf_Word u128;
if (offset >= dbg->sections[IDX_debug_info].size)
{
/* Completely out of bounds. */
__libdwarf_error (dbg, error, DW_E_INVALID_OFFSET);
return DW_DLV_ERROR;
}
/* Find the compile unit this address belongs to. */
cu = find_cu (dbg, offset, error);
if (cu == NULL)
return DW_DLV_ERROR;
/* Creata a new die. */
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. */
die_addr = (Dwarf_Small *) dbg->sections[IDX_debug_info].addr + offset;
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;
}
*return_die = new_die;
return DW_DLV_OK;
}