/*
This function performs error handling as described in the
libdwarf consumer document section 3. Dbg is the Dwarf_debug
structure being processed. Error is a pointer to the pointer
to the error descriptor that will be returned. Errval is an
error code listed in dwarf_error.h.
*/
void
_dwarf_error(Dwarf_Debug dbg, Dwarf_Error * error, Dwarf_Sword errval)
{
Dwarf_Error errptr;
/*
Allow NULL dbg on entry, since sometimes that can happen and we
want to report the upper-level error, not this one. */
if (error != NULL) {
/*
If dbg is NULL, use the alternate error struct. However,
this will overwrite the earlier error. */
if (dbg != NULL) {
errptr =
(Dwarf_Error) _dwarf_get_alloc(dbg, DW_DLA_ERROR, 1);
if (errptr == NULL) {
fprintf(stderr,
"Could not allocate Dwarf_Error structure, "
"abort() in libdwarf.\n");
abort();
}
} else {
/* We have no dbg to work with. dwarf_init failed. We hack
up a special area. */
errptr = _dwarf_special_no_dbg_error_malloc();
if (errptr == NULL) {
fprintf(stderr,
"Could not allocate Dwarf_Error structure, "
"abort() in libdwarf..\n");
abort();
}
}
errptr->er_errval = errval;
*error = errptr;
return;
}
if (dbg != NULL && dbg->de_errhand != NULL) {
errptr = (Dwarf_Error) _dwarf_get_alloc(dbg, DW_DLA_ERROR, 1);
if (errptr == NULL) {
fprintf(stderr, "Could not allocate Dwarf_Error structure,"
" abort() in libdwarf.\n");
abort();
}
errptr->er_errval = errval;
dbg->de_errhand(errptr, dbg->de_errarg);
return;
}
fprintf(stderr,
"abort() in libdwarf. No error argument, no handler.\n");
abort();
}
/* This function performs error handling as described in the
libdwarf consumer document section 3. Dbg is the Dwarf_debug
structure being processed. Error is a pointer to the pointer
to the error descriptor that will be returned. Errval is an
error code listed in dwarf_error.h.
If the malloc arena is exhausted we return a pointer to
a special static error record. This special singleton
is mostly ignored by dwarf_dealloc().
Users should not be storing Dwarf_Error pointers
for long so this singleton is only going to cause
confusion when callers try to save an out-of-memory
Dwarf_Error pointer.
The _dwarf_failsafe_error is intended to
be an improvement over an abort() call.
The failsafe means we will not abort due to
a Dwarf_Error struct creation.
*/
void
_dwarf_error(Dwarf_Debug dbg, Dwarf_Error * error, Dwarf_Sword errval)
{
Dwarf_Error errptr;
/* Allow NULL dbg on entry, since sometimes that can happen and we
want to report the upper-level error, not this one. */
if (error != NULL) {
/* If dbg is NULL, use the alternate error struct. However,
this will overwrite the earlier error. */
if (dbg != NULL) {
errptr =
(Dwarf_Error) _dwarf_get_alloc(dbg, DW_DLA_ERROR, 1);
if (!errptr) {
errptr = &_dwarf_failsafe_error;
errptr->er_static_alloc = DE_STATIC;
} else {
errptr->er_static_alloc = DE_STANDARD;
}
} else {
/* We have no dbg to work with. dwarf_init failed. We hack
up a special area. */
errptr = _dwarf_special_no_dbg_error_malloc();
if (!errptr) {
errptr = &_dwarf_failsafe_error;
errptr->er_static_alloc = DE_STATIC;
} else {
errptr->er_static_alloc = DE_MALLOC;
}
}
errptr->er_errval = errval;
*error = errptr;
return;
}
if (dbg != NULL && dbg->de_errhand != NULL) {
errptr = (Dwarf_Error) _dwarf_get_alloc(dbg, DW_DLA_ERROR, 1);
if (errptr == NULL) {
errptr = &_dwarf_failsafe_error;
errptr->er_static_alloc = DE_STATIC;
}
errptr->er_errval = errval;
dbg->de_errhand(errptr, dbg->de_errarg);
return;
}
fflush(stdout);
fprintf(stdout,
"\nNow abort() in libdwarf. "
"No error argument or handler available.\n");
fflush(stdout);
abort();
}
/*
This function returns a pointer to a region
of memory. For alloc_types that are not
strings or lists of pointers, only 1 struct
can be requested at a time. This is indicated
by an input count of 1. For strings, count
equals the length of the string it will
contain, i.e it the length of the string
plus 1 for the terminating null. For lists
of pointers, count is equal to the number of
pointers. For DW_DLA_FRAME_BLOCK, and
DW_DLA_LOC_BLOCK allocation types also, count
is the count of the number of structs needed.
This function cannot be used to allocate a
Dwarf_Debug_s struct.
*/
Dwarf_Ptr
_dwarf_get_alloc(Dwarf_Debug dbg,
Dwarf_Small alloc_type, Dwarf_Unsigned count)
{
Dwarf_Alloc_Hdr alloc_hdr;
Dwarf_Ptr ret_mem;
Dwarf_Signed size = 0;
unsigned int index;
unsigned int type = alloc_type;
if (dbg == NULL) {
return (NULL);
}
if (type >= ALLOC_AREA_INDEX_TABLE_MAX) {
/* internal error */
return NULL;
}
index = index_into_allocated[type].ia_al_num;
/* zero also illegal but not tested for */
/* If the Dwarf_Debug is not fully set up, we will get index 0 for
any type and must do something. 'Not fully set up' can only
happen for DW_DLA_ERROR, I (davea) believe, and for that we call
special code here.. */
if (index == 0) {
if (alloc_type == DW_DLA_STRING) {
size = count;
} else if (alloc_type == DW_DLA_LIST) {
size = count * sizeof(Dwarf_Ptr);
} else if (alloc_type == DW_DLA_FRAME_BLOCK) {
size = count * sizeof(Dwarf_Frame_Op);
} else if (alloc_type == DW_DLA_LOC_BLOCK) {
size = count * sizeof(Dwarf_Loc);
} else if (alloc_type == DW_DLA_ADDR) {
size = count *
(sizeof(Dwarf_Addr) > sizeof(Dwarf_Off) ?
sizeof(Dwarf_Addr) : sizeof(Dwarf_Off));
} else if (alloc_type == DW_DLA_ERROR) {
return _dwarf_special_no_dbg_error_malloc();
} else {
/* If we get here, there is a disastrous programming error
somewhere. */
#ifdef DEBUG
fprintf(stderr,
"libdwarf Internal error: type %d unexpected\n",
(int) type);
#endif
}
} else {
alloc_hdr = &dbg->de_alloc_hdr[index];
if (alloc_hdr->ah_bytes_one_struct > 0) {
#ifdef DWARF_SIMPLE_MALLOC
size = alloc_hdr->ah_bytes_one_struct;
#else
return (_dwarf_find_memory(alloc_hdr));
#endif
} else {
/* Special case: should not really happen at all. */
if (type == DW_DLA_ERROR) {
/* dwarf_init failure. Because dbg is incomplete we
won't use it to record the malloc. */
return _dwarf_special_no_dbg_error_malloc();
} else {
/* If we get here, there is a disastrous programming
error somewhere. */
#ifdef DWARF_SIMPLE_MALLOC
_dwarf_simple_malloc_botch(3);
#endif
#ifdef DEBUG
fprintf(stderr,
"libdwarf Internal error: Type %d unexpected\n",
(int) type);
#endif
}
}
}
ret_mem = malloc(size);
#ifdef DWARF_SIMPLE_MALLOC
_dwarf_simple_malloc_add_to_list(dbg,ret_mem,(unsigned long)size,
alloc_type);
#endif
if (ret_mem != NULL)
memset(ret_mem,0, size);
return (ret_mem);
}
