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DWARF_GET_FDE_LIST(3)      Library Functions Manual      DWARF_GET_FDE_LIST(3)

NAME
     dwarf_get_fde_list - retrieve frame information

LIBRARY
     DWARF Access Library (libdwarf, -ldwarf)

SYNOPSIS
     #include <libdwarf.h>

     int
     dwarf_get_fde_list(Dwarf_Debug dbg, Dwarf_Cie **cie_list,
         Dwarf_Signed *cie_count, Dwarf_Fde **fde_list,
         Dwarf_Signed *fde_count, Dwarf_Error *err);

     int
     dwarf_get_fde_list_eh(Dwarf_Debug dbg, Dwarf_Cie **cie_list,
         Dwarf_Signed *cie_count, Dwarf_Fde **fde_list,
         Dwarf_Signed *fde_count, Dwarf_Error *err);

DESCRIPTION
     These functions retrieve frame related information for the specified
     DWARF debug context.

     Function dwarf_get_fde_list() retrieves frame information from the DWARF
     section named ".debug_frame".  For objects containing GNU style C++
     exception handling information, the function dwarf_get_fde_list_eh()
     retrieves frame information from the section named ".eh_frame".

     Frame information is returned using opaque descriptors of type Dwarf_Cie
     and Dwarf_Fde.  Applications need to use the other frame related
     functions in the DWARF(3) API set to retrieve the information contained
     in these descriptors.

     Argument dbg should reference a DWARF debug context allocated using
     dwarf_init(3).

     Argument cie_list should point to a location that will be set to a
     pointer to an array of Dwarf_Cie descriptors.

     Argument cie_count should point to a location that will be set to the
     number of Dwarf_Cie descriptors returned.

     Argument fde_list should point to a location that will be set to a
     pointer to an array of Dwarf_Fde descriptors.

     Argument fde_count should point to a location that will be set to the
     number of Dwarf_Fde 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 areas used for the arrays returned in arguments cie_list and
     fde_list are owned by the DWARF Access Library (libdwarf, -ldwarf).
     Application code should not attempt to directly free these areas.
     Portable applications should instead use the
     dwarf_fde_cie_list_dealloc(3) function to indicate that these memory
     areas may be freed.

RETURN VALUES
     On success, these functions returns DW_DLV_OK.  They return
     DW_DLV_NO_ENTRY if there is no frame information associated with the
     given DWARF debug context.  In case of an error, they return DW_DLV_ERROR
     and set the argument err.

EXAMPLES
     To obtain frame information from the ".debug_frame" section, use:

           Dwarf_Debug dbg;
           Dwarf_Cie *cie_list, cie;
           Dwarf_Fde *fde_list, fde;
           Dwarf_Off fde_offset, cie_offset;
           Dwarf_Unsigned func_len, fde_length, fde_instlen;
           Dwarf_Signed cie_count, fde_count, cie_index;
           Dwarf_Addr low_pc;
           Dwarf_Ptr fde_addr, fde_inst, cie_inst;
           Dwarf_Error de;
           int i;

           if (dwarf_get_fde_list(dbg, &cie_list, &cie_count,
               &fde_list, &fde_count, &de) != DW_DLV_OK) {
                   errx(EXIT_FAILURE, "dwarf_get_fde_list failed: %s",
                       dwarf_errmsg(de));
           }

           for (i = 0; i < fde_count; i++) {
                   if (dwarf_get_fde_n(fde_list, i, &fde, &de) != DW_DLV_OK) {
                           warnx("dwarf_get_fde_n failed: %s",
                               dwarf_errmsg(de));
                           continue;
                   }
                   if (dwarf_get_cie_of_fde(fde, &cie, &de) != DW_DLV_OK) {
                           warnx("dwarf_get_fde_n failed: %s",
                               dwarf_errmsg(de));
                           continue;
                   }
                   if (dwarf_get_fde_range(fde, &low_pc, &func_len, &fde_addr,
                       &fde_length, &cie_offset, &cie_index, &fde_offset,
                       &de) != DW_DLV_OK) {
                           warnx("dwarf_get_fde_range failed: %s",
                               dwarf_errmsg(de));
                           continue;
                   }
                   if (dwarf_get_fde_instr_bytes(fde, &fde_inst, &fde_instlen,
                       &de) != DW_DLV_OK) {
                           warnx("dwarf_get_fde_instr_bytes failed: %s",
                               dwarf_errmsg(de));
                           continue;
                   }

                   /* ... Use the retrieved frame information ... */
           }

           /* Indicate that the returned arrays may be freed. */
           dwarf_fde_cie_list_dealloc(dbg, cie_list, cie_count, fde_list,
               fde_count);

ERRORS
     These functions may fail with the following errors:

     [DW_DLE_ARGUMENT]       One of the arguments dbg, cie_list, cie_count,
                             fde_list or fde_count was NULL.

     [DW_DLE_NO_ENTRY]       There is no frame information associated with the
                             giving DWARF debug context.

SEE ALSO
     dwarf(3), dwarf_fde_cie_list_dealloc(3), dwarf_get_cie_index(3),
     dwarf_get_cie_of_fde(3), dwarf_get_fde_at_pc(3),
     dwarf_get_fde_instr_bytes(3), dwarf_get_fde_n(3), dwarf_get_fde_range(3),
     dwarf_set_frame_cfa_value(3), dwarf_set_frame_rule_initial_value(3),
     dwarf_set_frame_rule_table_size(3), dwarf_set_frame_same_value(3),
     dwarf_set_frame_undefined_value(3)

NetBSD 10.99                   November 9, 2011                   NetBSD 10.99