Manual Pages  — DWARF_GET_SECTION_BYTES

dwarf_get_section_bytes – retrieve ELF section byte streams

LIBRARY SYNOPSIS DESCRIPTION Memory Management RETURN VALUES EXAMPLES ERRORS SEE ALSO

DWARF Access Library (libdwarf, -ldwarf)

#include <libdwarf.h>

Dwarf_Ptr
dwarf_get_section_bytes(Dwarf_P_Debug dbg, Dwarf_Signed dwarf_section, Dwarf_Signed *elf_section_index, Dwarf_Unsigned *length, Dwarf_Error *err);

The memory areas used for the returned ELF section byte streams should be freed using the function dwarf_producer_finish().

On success, function dwarf_get_section_bytes() returns a pointer to a ELF section byte stream. In case of an error, function dwarf_get_section_bytes() will return NULL and set the argument err.

To generate and retrieve ELF section byte streams, use:

Dwarf_P_Debug dbg;
Dwarf_Signed count, i, sec_index;
Dwarf_Unsigned len;
Dwarf_Ptr bytes;
Dwarf_Error de;

/* ... Assume that `dbg' refers to a DWARF producer instance,
 * and that application code has added DWARF debugging
 * information to the producer instance. ...
 */
if ((count = dwarf_transform_to_disk_form(dbg, &de)) ==
    DW_DLV_NOCOUNT) {
        warnx("dwarf_transform_to_disk_form failed: %s",
            dwarf_errmsg(-1));
        return;
}

/* Retrieve section data. */
for (i = 0; i < count; i++) {
        bytes = dwarf_get_section_bytes(dbg, i, &sec_index, &len,
            &de);
        if (bytes == NULL) {
                warnx("dwarf_get_section_bytes failed: %s",
                    dwarf_errmsg(-1));
                continue;
        }
        /* ... use the returned byte stream ... */
}

/* Release resources. */
dwarf_producer_finish(dbg, &de);

Function dwarf_get_section_bytes() can fail with:

[DW_DLE_ARGUMENT]	One of the arguments dbg, elf_section_index, or length was NULL.
[DW_DLE_NO_ENTRY]	There were no more ELF sections to retrieve, or the function was called before a call to dwarf_transform_to_disk_form(3).