dwarf_die_deliv.c revision 07dc1947c362e187fb955d283b692f8769dd5def
/*
Copyright (C) 2000-2006 Silicon Graphics, Inc. All Rights Reserved.
Portions Copyright (C) 2007-2010 David Anderson. All Rights Reserved.
under the terms of version 2.1 of the GNU Lesser General Public License
as published by the Free Software Foundation.
This program is distributed in the hope that it would be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Further, this software is distributed without any warranty that it is
free of the rightful claim of any third person regarding infringement
or the like. Any license provided herein, whether implied or
otherwise, applies only to this software file. Patent licenses, if
any, provided herein do not apply to combinations of this program with
other software, or any other product whatsoever.
You should have received a copy of the GNU Lesser General Public
License along with this program; if not, write the Free Software
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston MA 02110-1301,
USA.
Contact information: Silicon Graphics, Inc., 1500 Crittenden Lane,
Mountain View, CA 94043, or:
For further information regarding this notice, see:
*/
/* The address of the Free Software Foundation is
Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
Boston, MA 02110-1301, USA.
SGI has moved from the Crittenden Lane address.
*/
#include "config.h"
#include "dwarf_incl.h"
#ifdef HAVE_ELF_H
#include <elf.h>
#endif
#include <stdio.h>
#include "dwarf_die_deliv.h"
/*
For a given Dwarf_Debug dbg, this function checks
if a CU that includes the given offset has been read
or not. If yes, it returns the Dwarf_CU_Context
for the CU. Otherwise it returns NULL. Being an
internal routine, it is assumed that a valid dbg
is passed.
**This is a sequential search. May be too slow.
If debug_info and debug_abbrev not loaded, this will
wind up returning NULL. So no need to load before calling
this.
*/
static Dwarf_CU_Context
{
return (NULL);
}
+ cu_context->cc_extension_size) {
return (cu_context);
}
}
}
+ cu_context->cc_extension_size) {
return (cu_context);
}
}
return (NULL);
}
/*
This routine checks the dwarf_offdie() list of
CU contexts for the right CU context.
*/
static Dwarf_CU_Context
{
return (cu_context);
return (NULL);
}
/*
This function is used to create a CU Context for
a compilation-unit that begins at offset in
.debug_info. The CU Context is attached to the
list of CU Contexts for this dbg. It is assumed
that the CU at offset has not been read before,
and so do not call this routine before making
sure of this with _dwarf_find_CU_Context().
Returns NULL on error. As always, being an
internal routine, assumes a good dbg.
This function must always set a dwarf error code
before returning NULL. Always.
*/
static Dwarf_CU_Context
{
Dwarf_Unsigned length = 0;
Dwarf_Byte_Ptr cu_ptr = 0;
int local_extension_size = 0;
int local_length_size = 0;
if (cu_context == NULL) {
return (NULL);
}
/* READ_AREA_LENGTH updates cu_ptr for consumed bytes */
cu_ptr, sizeof(Dwarf_Half));
cu_ptr += sizeof(Dwarf_Half);
return (NULL);
}
return (NULL);
}
return (NULL);
}
return (NULL);
}
} else {
}
return (cu_context);
}
/*
Returns offset of next compilation-unit thru next_cu_offset
pointer.
It basically sequentially moves from one
cu to the next. The current cu is recorded
internally by libdwarf.
The _b form is new for DWARF4 adding new returned fields.
*/
int
Dwarf_Error * error)
{
return dwarf_next_cu_header_b(dbg,
0,0,
error);
}
int
Dwarf_Error * error)
{
/* Offset for current and new CU. */
Dwarf_Unsigned new_offset = 0;
/* CU Context for current CU. */
/* ***** BEGIN CODE ***** */
return (DW_DLV_ERROR);
}
/*
Get offset into .debug_info of next CU. If dbg has no context,
this has to be the first one. */
new_offset = 0;
return res;
}
}
} else {
}
/*
Check that there is room in .debug_info beyond the new offset
for at least a new cu header. If not, return 0 to indicate end
of debug_info section, and reset de_cu_debug_info_offset to
enable looping back through the cu's. */
return (DW_DLV_NO_ENTRY);
}
/* Check if this CU has been read before. */
/* If not, make CU Context for it. */
if (cu_context == NULL) {
if (cu_context == NULL) {
/* Error if CU Context could not be made. Since
_dwarf_make_CU_Context has already registered an error
we do not do that here: we let the lower error pass
thru. */
return (DW_DLV_ERROR);
}
}
if (cu_header_length != NULL)
if (version_stamp != NULL)
if (abbrev_offset != NULL)
if (address_size != NULL)
if (offset_size != NULL)
if (extension_size != NULL)
return (DW_DLV_OK);
}
/*
This function does two slightly different things
depending on the input flag want_AT_sibling. If
this flag is true, it checks if the input die has
a DW_AT_sibling attribute. If it does it returns
a pointer to the start of the sibling die in the
.debug_info section. Otherwise it behaves the
same as the want_AT_sibling false case.
If the want_AT_sibling flag is false, it returns
a pointer to the immediately adjacent die in the
.debug_info section.
Die_info_end points to the end of the .debug_info
portion for the cu the die belongs to. It is used
to check that the search for the next die does not
cross the end of the current cu. Cu_info_start points
to the start of the .debug_info portion for the
current cu, and is used to add to the offset for
DW_AT_sibling attributes. Finally, has_die_child
is a pointer to a Dwarf_Bool that is set true if
the present die has children, false otherwise.
However, in case want_AT_child is true and the die
has a DW_AT_sibling attribute *has_die_child is set
false to indicate that the children are being skipped.
die_info_end points to the last byte+1 of the cu.
*/
static Dwarf_Byte_Ptr
{
Dwarf_Byte_Ptr info_ptr = 0;
Dwarf_Byte_Ptr abbrev_ptr = 0;
Dwarf_Word abbrev_code = 0;
Dwarf_Half attr = 0;
Dwarf_Half attr_form = 0;
Dwarf_Unsigned offset = 0;
Dwarf_Word leb128_length = 0;
Dwarf_Unsigned utmp = 0;
Dwarf_Debug dbg = 0;
if (abbrev_code == 0) {
return NULL;
}
if (abbrev_list == NULL) {
return (NULL);
}
do {
if (attr_form == DW_FORM_indirect) {
/* DECODE_LEB128_UWORD updates info_ptr */
}
switch (attr_form) {
case DW_FORM_ref1:
break;
case DW_FORM_ref2:
/* READ_UNALIGNED does not update info_ptr */
info_ptr, sizeof(Dwarf_Half));
break;
case DW_FORM_ref4:
info_ptr, sizeof(Dwarf_ufixed));
break;
case DW_FORM_ref8:
info_ptr, sizeof(Dwarf_Unsigned));
break;
case DW_FORM_ref_udata:
offset =
break;
case DW_FORM_ref_addr:
/* Very unusual. The FORM is intended to refer to
a different CU, but a different CU cannot
be a sibling, can it?
We could ignore this and treat as if no DW_AT_sibling
present. Or derive the offset from it and if
it is in the same CU use it directly.
The offset here is *supposed* to be a global offset,
so adding cu_info_start is wrong to any offset
we find here unless cu_info_start
is zero! Lets pretend there is no DW_AT_sibling
attribute. */
goto no_sibling_attr;
default:
return (NULL);
}
/* Reset *has_die_child to indicate children skipped. */
*has_die_child = false;
/* A value beyond die_info_end indicates an error. Exactly
at die_info_end means 1-past-cu-end and simply means we
are at the end, do not return NULL. Higher level code
will detect that we are at the end. */
/* Error case, bad DWARF. */
return (NULL);
}
/* At or before end-of-cu */
return (cu_info_start + offset);
}
if (attr_form != 0) {
/* It is ok for info_ptr == die_info_end, as we will test
later before using a too-large info_ptr */
if (info_ptr > die_info_end) {
/* More than one-past-end indicates a bug somewhere,
likely bad dwarf generation. */
return (NULL);
}
}
return (info_ptr);
}
/*
Given a Dwarf_Debug dbg, and a Dwarf_Die die, it returns
a Dwarf_Die for the sibling of die. In case die is NULL,
it returns (thru ptr) a Dwarf_Die for the first die in the current
cu in dbg. Returns DW_DLV_ERROR on error.
It is assumed that every sibling chain including those with
only one element is terminated with a NULL die, except a
chain with only a NULL die.
The algorithm moves from one die to the adjacent one. It
returns when the depth of children it sees equals the number
of sibling chain terminations. A single count, child_depth
is used to track the depth of children and sibling terminations
encountered. Child_depth is incremented when a die has the
Has-Child flag set unless the child happens to be a NULL die.
Child_depth is decremented when a die has Has-Child false,
and the adjacent die is NULL. Algorithm returns when
child_depth is 0.
**NOTE: Do not modify input die, since it is used at the end.
*/
int
{
/* die_info_end points 1-past end of die (once set) */
Dwarf_Word abbrev_code = 0;
Dwarf_Unsigned utmp = 0;
return (DW_DLV_ERROR);
}
/* Find root die of cu */
/* die_info_end is untouched here, need not be set in this
branch. */
/* If we've not loaded debug_info, de_cu_context will be NULL,
so no need to laod */
return (DW_DLV_ERROR);
}
} else {
/* Find sibling die. */
Dwarf_Bool has_child = false;
Dwarf_Sword child_depth = 0;
/* We cannot have a legal die unless debug_info was loaded, so
no need to load debug_info here. */
if (*die_info_ptr == 0) {
return (DW_DLV_NO_ENTRY);
}
if ((*die_info_ptr) == 0) {
return (DW_DLV_NO_ENTRY);
}
child_depth = 0;
do {
cu_info_start, true,
&has_child);
if (die_info_ptr == NULL) {
return (DW_DLV_ERROR);
}
/* die_info_end is one past end. Do not read it!
A test for ``!= die_info_end'' would work as well,
but perhaps < reads more like the meaning. */
if(die_info_ptr < die_info_end) {
if ((*die_info_ptr) == 0 && has_child) {
die_info_ptr++;
has_child = false;
}
}
/* die_info_ptr can be one-past-end. */
if ((die_info_ptr == die_info_end) ||
((*die_info_ptr) == 0)) {
for (; child_depth > 0 && *die_info_ptr == 0;
child_depth--, die_info_ptr++);
} else {
}
} while (child_depth != 0);
}
/* die_info_ptr > die_info_end is really a bug (possibly in dwarf
generation)(but we are past end, no more DIEs here), whereas
die_info_ptr == die_info_end means 'one past end, no more DIEs
here'. */
return (DW_DLV_NO_ENTRY);
}
if ((*die_info_ptr) == 0) {
return (DW_DLV_NO_ENTRY);
}
return (DW_DLV_ERROR);
}
if (abbrev_code == 0) {
/* Zero means a null DIE */
return (DW_DLV_NO_ENTRY);
}
ab_tag !=
return (DW_DLV_ERROR);
}
return (DW_DLV_OK);
}
int
{
/* die_info_end points one-past-end of die area. */
Dwarf_Bool has_die_child = 0;
Dwarf_Word abbrev_code = 0;
Dwarf_Unsigned utmp = 0;
/* NULL die has no child. */
if ((*die_info_ptr) == 0)
return (DW_DLV_NO_ENTRY);
die_info_end, NULL, false,
if (die_info_ptr == NULL) {
return (DW_DLV_ERROR);
}
if (!has_die_child)
return (DW_DLV_NO_ENTRY);
return (DW_DLV_ERROR);
}
if (abbrev_code == 0) {
/* We have arrived at a null DIE, at the end of a CU or the end
of a list of siblings. */
*caller_ret_die = 0;
return DW_DLV_NO_ENTRY;
}
return (DW_DLV_ERROR);
}
return (DW_DLV_OK);
}
/*
Given a (global, not cu_relative) die offset, this returns
a pointer to a DIE thru *new_die.
It is up to the caller to do a
dwarf_dealloc(dbg,*new_die,DW_DLE_DIE);
*/
int
{
Dwarf_Off new_cu_offset = 0;
Dwarf_Byte_Ptr info_ptr = 0;
Dwarf_Unsigned utmp = 0;
return (DW_DLV_ERROR);
}
if (cu_context == NULL)
if (cu_context == NULL) {
return res;
}
}
do {
if ((new_cu_offset +
return (DW_DLV_ERROR);
}
if (cu_context == NULL) {
/* Error if CU Context could not be made. Since
_dwarf_make_CU_Context has already registered an
error we do not do that here: we let the lower error
pass thru. */
return (DW_DLV_ERROR);
}
} else {
}
} while (offset >= new_cu_offset);
}
return (DW_DLV_ERROR);
}
abbrev_code = utmp;
if (abbrev_code == 0) {
/* we are at a null DIE (or there is a bug). */
*new_die = 0;
return DW_DLV_NO_ENTRY;
}
return (DW_DLV_ERROR);
}
return (DW_DLV_OK);
}