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DWARF_GET_ABBREV(3) FreeBSD Library Functions Manual DWARF_GET_ABBREV(3)
NAME
dwarf_get_abbrev - retrieve abbreviation information
LIBRARY
DWARF Access Library (libdwarf, -ldwarf)
SYNOPSIS
#include <libdwarf.h>
int
dwarf_get_abbrev(Dwarf_Debug dbg, Dwarf_Unsigned offset,
Dwarf_Abbrev *ret_abbrev, Dwarf_Unsigned *length,
Dwarf_Unsigned *attr_count, Dwarf_Error *err);
DESCRIPTION
Function dwarf_get_abbrev() retrieves information about an abbreviation
from the DWARF abbreviations section, ".debug_abbrev". Abbreviation
information is returned using an opaque descriptor of type Dwarf_Abbrev.
The returned Dwarf_Abbrev descriptor may then be passed to the other
abbreviation related APIs in the DWARF(3) API to retrieve specific
information about the abbreviation.
Argument dbg should reference a DWARF debug context allocated using
dwarf_init(3).
Argument offset should be an offset, relative to the ".debug_abbrev"
section, to the start of an abbreviation entry.
Argument ret_abbrev should point to a location that will hold a pointer
to the returned Dwarf_Abbrev descriptor.
Argument length should point to a location that will hold the number of
bytes used by the abbrevation in the DWARF ".debug_abbrev" section.
Argument attr_count should point to a location that will hold the number
of attributes in the abbrevation.
If argument err is not NULL, it will be used to store error information
in case of an error.
Memory Management
The memory area used for the Dwarf_Abbrev descriptor returned in argument
ret_abbrev is allocated by the DWARF Access Library (libdwarf, -ldwarf).
Application code should use function dwarf_dealloc() with the allocation
type DW_DLA_ABBREV to free the memory area when the Dwarf_Abbrev
descriptor is no longer needed.
Application Programming Notes
The last abbreviation entry in a standard DWARF abbreviation section will
have a special length value of 1.
RETURN VALUES
Function dwarf_get_abbrev() returns DW_DLV_OK when it succeeds. It
returns DW_DLV_NO_ENTRY if there is no abbreviation information at offset
offset. In case of an error, it returns DW_DLV_ERROR and sets the
argument err.
Dwarf_Unsigned length, attr_count;
Dwarf_Half tag;
Dwarf_Error de;
int ret;
while ((ret = dwarf_next_cu_header(dbg, NULL, NULL, &aboff,
NULL, NULL, &de)) == DW_DLV_OK) {
while ((ret = dwarf_get_abbrev(re->dbg, aboff, &ab, &length,
&attr_count, &de)) == DW_DLV_OK) {
if (length == 1) /* Last entry. */
break;
aboff += length;
if (dwarf_get_abbrev_tag(ab, &tag, &de) != DW_DLV_OK) {
warnx("dwarf_get_abbrev_tag failed: %s",
dwarf_errmsg(de));
continue;
}
if (ret != DW_DLV_OK)
warnx("dwarf_get_abbrev: %s", dwarf_errmsg(de));
}
if (ret == DW_DLV_ERROR)
warnx("dwarf_next_cu_header: %s", dwarf_errmsg(de));
ERRORS
Function dwarf_get_abbrev() can fail with:
[DW_DLE_ARGUMENT] One of the arguments dbg, ret_abbrev, length or
attr_count was NULL.
[DW_DLE_NO_ENTRY] There is no abbreviation information at offset
offset.
SEE ALSO
dwarf(3), dwarf_dealloc(3), dwarf_get_abbrev_children_flag(3),
dwarf_get_abbrev_code(3), dwarf_get_abbrev_entry(3),
dwarf_get_abbrev_tag(3)
FreeBSD 14.2-RELEASE March 27, 2011 FreeBSD 14.2-RELEASE