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 associated with the specified debugging context. In case of an error, it returns DW_DLV_ERROR and sets the argument err.

EXAMPLES

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. */
}

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.