static int
die_mem_offset(dwarf_t *dw, Dwarf_Die die, Dwarf_Half name,
Dwarf_Unsigned *valp, int req)
{
Dwarf_Attribute attr;
Dwarf_Locdesc *loc;
Dwarf_Signed locnum;
if ((attr = die_attr(dw, die, name, req)) == NULL)
return (0); /* die_attr will terminate for us if necessary */
if (dwarf_loclist(attr, &loc, &locnum, &dw->dw_err) != DW_DLV_OK) {
terminate("die %llu: failed to get mem offset location list\n",
die_off(dw, die));
}
dwarf_dealloc(dw->dw_dw, attr, DW_DLA_ATTR);
if (locnum != 1 || loc->ld_s->lr_atom != DW_OP_plus_uconst) {
terminate("die %llu: cannot parse member offset\n",
die_off(dw, die));
}
*valp = loc->ld_s->lr_number;
dwarf_dealloc(dw->dw_dw, loc->ld_s, DW_DLA_LOC_BLOCK);
dwarf_dealloc(dw->dw_dw, loc, DW_DLA_LOCDESC);
return (1);
}
static void DC_get_location_attr_value(Dwarf_Attribute at, DC_location *dcl){
/*
* It is assumed that at has a block form, and is a location list
* so this won't fail. Caller is responsible for checking.
*/
Dwarf_Locdesc *locationList;
Dwarf_Signed listLength;
Dwarf_Error error;
int frameRel = 0;
long offset = 0;
int i;
int ret = dwarf_loclist( at, &locationList, &listLength, &error );
if( ret != DW_DLV_OK ){
return;
}
/*Get the location info*/
decode_location(locationList,listLength,&(dcl->offset),NULL,&(dcl->isFrameOffset));
/*Clean up*/
for( i = 0; i < listLength; ++i){
dwarf_dealloc(d,locationList[i].ld_s,DW_DLA_LOC_BLOCK);
}
dwarf_dealloc(d,locationList,DW_DLA_LOCDESC);
}
/*
Return DW_DLV_OK if handling this went ok.
*/
static int
handle_attr_locdesc(Dwarf_Debug dbg, Dwarf_Die die, Dwarf_Half attrnum,
Dwarf_Error * perr)
{
int retval = DW_DLV_OK;
Dwarf_Attribute attr;
Dwarf_Locdesc *llbuf;
Dwarf_Signed i;
Dwarf_Off offset;
Dwarf_Loc *locp;
unsigned int entindx;
int res;
int ares;
ares = dwarf_attr(die, attrnum, &attr, perr);
if (ares == DW_DLV_OK) {
Dwarf_Half form;
int fres = dwarf_whatform(attr, &form, perr);
if (fres == DW_DLV_OK) {
switch (form) {
case DW_FORM_block1:
case DW_FORM_block2:
case DW_FORM_block4:
/* must be location description */
res = dwarf_attr_offset(die, attr, &offset, perr);
llbuf = 0;
if (res == DW_DLV_OK) {
Dwarf_Signed count;
int lres =
dwarf_loclist(attr, &llbuf, &count, perr);
if (lres != DW_DLV_OK) {
return lres;
}
if (count != 1) {
/* this cannot happen! */
/* perr? */
_dwarf_error(dbg, perr,
DW_DLE_LOCDESC_COUNT_WRONG);
retval = DW_DLV_ERROR;
return retval;
}
for (i = 0; i < count; ++i) {
unsigned int ents = llbuf[i].ld_cents;
locp = llbuf[i].ld_s;
for (entindx = 0; entindx < ents; entindx++) {
Dwarf_Loc *llocp;
llocp = locp + entindx;
if (llocp->lr_atom == DW_OP_addr) {
send_addr_note(DW_SECTION_INFO, offset +
llocp->lr_offset + 1
/* The offset is the
offset of the atom,
** and we know the
addr is 1 past it. */
, llocp->lr_number);
}
}
}
if (count > 0) {
for (i = 0; i < count; ++i) {
dwarf_dealloc(dbg, llbuf[i].ld_s,
DW_DLA_LOC_BLOCK);
}
dwarf_dealloc(dbg, llbuf, DW_DLA_LOCDESC);
}
} else {
retval = res;
}
break;
default:
/* must be a const offset in debug_loc */
; /* do nothing */
}
dwarf_dealloc(dbg, attr, DW_DLA_ATTR);
} /* else error or no entry */
retval = fres;
} else {
retval = ares;
}
return retval;
}
error_t print_local_var(mygdb_info_t* gdb_info, Dwarf_Die var_die, char* var_name){
Dwarf_Half tag;
Dwarf_Error err;
unsigned long var_addr;
Dwarf_Attribute* attrs;
Dwarf_Locdesc* locs_var;
Dwarf_Signed attrcount, i, cnt_var;
if (dwarf_tag(var_die, &tag, &err) != DW_DLV_OK)
return E_FATAL;
/* Make sure to only have a var die */
if (tag != DW_TAG_variable)
return E_FATAL;
/* Grab the DIEs attributes */
if (dwarf_attrlist(var_die, &attrs, &attrcount, &err) != DW_DLV_OK)
return E_FATAL;
for (i = 0; i < attrcount; ++i) {
Dwarf_Half attrcode;
if (dwarf_whatattr(attrs[i], &attrcode, &err) != DW_DLV_OK)
return E_FATAL;
if (attrcode == DW_AT_location)
break;
}
if( attrs[i] == NULL ){
printf("Failed to find the DW_AT_location attribute\n");
return E_NON_FATAL;
}
if( dwarf_loclist(attrs[i], &locs_var, &cnt_var, &err) != DW_DLV_OK){
printf("dwarf_loclist failed\n");
return E_FATAL;
}
if((cnt_var != 1) || (locs_var[0].ld_cents != 1) || (locs_var[0].ld_s[0].lr_atom != DW_OP_fbreg)){
fprintf(stderr, "Unexpected location information\n");
return E_NON_FATAL;
}
struct user_regs_struct regs;
if( ptrace(PTRACE_GETREGS, gdb_info->child_pid, NULL, ®s ) < 0 )
return E_FATAL;
var_addr = (unsigned long)(regs.rbp + (long)locs_var[0].ld_s[0].lr_number + 16);
errno = 0;
unsigned long data;
data = ptrace(PTRACE_PEEKTEXT, gdb_info->child_pid, (void*)var_addr);
if(errno){
printf("peektext failed\n");
return E_FATAL;
}
printf("%s = %lu\n", var_name, data);
return E_NONE;
}
