NAME
dwarf_attrlist —
retrieve DWARF
attribute descriptors
LIBRARY
DWARF Access Library (libdwarf, -ldwarf)
SYNOPSIS
#include <libdwarf.h>
int
dwarf_attrlist(
Dwarf_Die die,
Dwarf_Attribute **attrbuf,
Dwarf_Signed
*attrcount,
Dwarf_Error *err);
DESCRIPTION
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.
Memory Management
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.
RETURN VALUES
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.
EXAMPLES
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. */
}
ERRORS
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.
SEE ALSO
dwarf(3),
dwarf_attr(3),
dwarf_dealloc(3),
dwarf_hasattr(3),
dwarf_hasform(3),
dwarf_whatattr(3),
dwarf_whatform(3)