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DWARF_GET_FDE_LIST(3)  FreeBSD 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++ ex-
     ception handling information, the function	dwarf_get_fde_list_eh()	re-
     trieves 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 func-
     tions 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).  Ap-
     plication code should not attempt to directly free	these areas.  Portable
     applications should instead use the dwarf_fde_cie_list_dealloc(3) func-
     tion 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 giv-
			ing 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)

FreeBSD	13.0		       November	9, 2011			  FreeBSD 13.0

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUES | EXAMPLES | ERRORS | SEE ALSO

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