dwarf_attrlist —
retrieve DWARF attribute descriptors
DWARF Access Library (libdwarf, -ldwarf)
#include
<libdwarf.h>
int
dwarf_attrlist(
Dwarf_Die
die,
Dwarf_Attribute **attrbuf,
Dwarf_Signed *attrcount,
Dwarf_Error *err);
Function
dwarf_attrlist() retrieves the DWARF
attribute descriptors associated with a debugging information entry descriptor
in argument
die. The descriptors are returned
as an array of values of the opaque type
Dwarf_Attribute. The data associated with
each returned attribute descriptor may be queried using the form query
functions in the
dwarf(3) API
set.
Argument
attrbuf points to a location that will
hold a pointer to the returned array of DWARF attribute descriptors. Argument
attrcount points to a location that will hold
the number of descriptors in the returned array.
If argument
err is non-NULL, it is used to
return an error descriptor in case of an error.
In the current implementation, the memory allocated for each DWARF attribute
descriptor and for the returned array of descriptors is managed by the library
and the application does not need to explicitly free the returned pointers.
However, for compatibility with other implementations of the
dwarf(3) API, the application
is permitted to pass the pointers returned by to the
dwarf_dealloc() function.
Function
dwarf_attrlist() returns
DW_DLV_OK
on success.
If the debugging information entry descriptor denoted by argument
die does not contain any attribute, the
function returns
DW_DLV_NO_ENTRY
and sets
argument
err. For other errors, it returns
DW_DLV_ERROR
and sets argument
err.
To retrieve the attribute list for a DWARF debugging information entry use:
Dwarf_Die dw_die;
Dwarf_Error dw_e;
Dwarf_Unsigned dw_count;
Dwarf_Attribute *dw_attributes;
int error, i;
... variable dw_die contains a reference to the DIE of interest ...
/* Retrieve the attribute list from the DIE. */
if ((error = dwarf_attrlist(dw_die, &dw_attributes, &dw_count,
&dw_e)) != DW_DLV_OK)
errx(EXIT_FAILURE, "dwarf_attrlist: %s", dwarf_errmsg(dw_e));
/* Process the attribute list. */
for (i = 0; i < dw_count; ++i) {
/* Use the returned pointers in dw_attributes[i] here. */
}
Function
dwarf_diename() can fail with the
following errors:
-
-
- [
DW_DLE_ARGUMENT
]
- Arguments die,
attrbuf, or
attrcount were NULL.
-
-
- [
DW_DLE_NO_ENTRY
]
- Argument die had no
attributes.
-
-
- [
DW_DLE_MEMORY
]
- An out of memory condition was encountered during the
execution of the function.
dwarf(3),
dwarf_attr(3),
dwarf_dealloc(3),
dwarf_hasattr(3),
dwarf_hasform(3),
dwarf_whatattr(3),
dwarf_whatform(3)