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DWARF_GET_SECTION_BYTES(3)                            Library Functions Manual

NAME
     dwarf_get_section_bytes - retrieve ELF section byte streams

LIBRARY
     DWARF Access Library (libdwarf, -ldwarf)

SYNOPSIS
     #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);

DESCRIPTION
     Function dwarf_get_section_bytes() returns the ELF section byte streams
     generated by a prior call to function dwarf_transform_to_disk_form(3).

     Each call to function dwarf_get_section_bytes() will return the byte
     stream for one ELF section.  The first call to this function will always
     return the first ELF section, and the subsequent calls will return the
     rest of sections in the order when they were generated, until the last
     one.  The total number of sections generated is returned by the function
     dwarf_transform_to_disk_form(3).

     Argument dbg should reference a DWARF producer instance allocated using
     the functions dwarf_producer_init(3) or dwarf_producer_init_b(3).

     Argument dwarf_section is currently ignored.

     Argument elf_section_index should point to a location which will be set
     to the section index value of the returned ELF section.

     Argument length should point to a location which will hold the length in
     bytes of the returned ELF section.

     If argument err is not NULL, it will be used to store error information
     in case of an error.

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

RETURN VALUES
     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.

EXAMPLES
     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);

ERRORS
     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).

SEE ALSO
     dwarf(3), dwarf_producer_finish(3), dwarf_producer_init(3),
     dwarf_producer_init_b(3), dwarf_reset_section_bytes(3),
     dwarf_transform_to_disk_form(3)

NetBSD 10.99                    August 26, 2011                   NetBSD 10.99