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dwarf_get_abbrev(3) [freebsd man page]

DWARF_GET_ABBREV(3)					   BSD 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''. Abbrevia- tion 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. 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. EXAMPLE
To loop through all the abbreviation information associated with a DWARF debug context, use: Dwarf_Debug dbg; Dwarf_Abbrev ab; Dwarf_Off aboff; 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)); SEE ALSO
dwarf(3), dwarf_dealloc(3), dwarf_get_abbrev_tag(3), dwarf_get_abbrev_code(3), dwarf_get_abbrev_children_flag(3), dwarf_get_abbrev_entry(3) BSD
March 27, 2011 BSD

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DWARF_GET_ARANGES(3)					   BSD Library Functions Manual 				      DWARF_GET_ARANGES(3)

NAME
dwarf_get_aranges -- retrieve program address space mappings LIBRARY
DWARF Access Library (libdwarf, -ldwarf) SYNOPSIS
#include <libdwarf.h> int dwarf_get_aranges(Dwarf_Debug dbg, Dwarf_Arange **ar_list, Dwarf_Signed *ar_cnt, Dwarf_Error *err); DESCRIPTION
The function dwarf_get_aranges() retrieves address range information from the ``.debug_aranges'' DWARF section. Information about address ranges is returned using opaque descriptors of type Dwarf_Arange, Argument dbg should reference a DWARF debug context allocated using dwarf_init(3). Argument ar_list should point to a location which will be set to a pointer to an array of Dwarf_Arange descriptors. Argument ar_cnt should point to a location which will be set to the number of descriptors returned. 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 array returned in argument ar_list is owned by DWARF Access Library (libdwarf, -ldwarf). Application code should not attempt to directly free this area. Portable applications should instead use dwarf_dealloc(3) to indicate that the memory area may be freed. RETURN VALUES
Function dwarf_get_aranges() returns DW_DLV_OK when it succeeds. It returns DW_DLV_NO_ENTRY if there is no ``.debug_aranges'' section asso- ciated with the specified debugging context. In case of an error, it returns DW_DLV_ERROR and sets the argument err. ERRORS
Function dwarf_get_aranges() can fail with: [DW_DLE_ARGUMENT] One of the arguments dbg, ar_list or ar_cnt was NULL. [DW_DLE_NO_ENTRY] The debugging context dbg did not contain a ``.debug_aranges'' string section. EXAMPLE
To loop through all the address lookup table entries, use: Dwarf_Debug dbg; Dwarf_Addr start; Dwarf_Arange *aranges; Dwarf_Off die_off; Dwarf_Signed i, cnt; Dwarf_Unsigned length; Dwarf_Error de; if (dwarf_get_aranges(dbg, &aranges, &cnt, &de) != DW_DLV_OK) errx(EXIT_FAILURE, "dwarf_get_aranges: %s", dwarf_errmsg(de)); for (i = 0; i < cnt; i++) { if (dwarf_get_arange_info(aranges[i], &start, &length, &die_off, &de) != DW_DLV_OK) { warnx("dwarf_get_arange_info: %s", dwarf_errmsg(de)); continue; } /* Do something with the returned information. */ } SEE ALSO
dwarf(3), dwarf_get_arange(3), dwarf_get_arange_cu_header_offset(3), dwarf_get_arange_info(3), dwarf_get_cu_die_offset(3) BSD
November 9, 2011 BSD

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