dwarf_expand_frame_instructions(3) [freebsd man page]

DWARF_EXPAND_FRAME_INSTRUCTIONS(3)			   BSD Library Functions Manual 			DWARF_EXPAND_FRAME_INSTRUCTIONS(3)

NAME

     dwarf_expand_frame_instructions -- expand frame instructions

LIBRARY

     DWARF Access Library (libdwarf, -ldwarf)

SYNOPSIS

     #include <libdwarf.h>

     int
     dwarf_expand_frame_instructions(Dwarf_Cie cie, Dwarf_Ptr instructions, Dwarf_Unsigned len, Dwarf_Frame_Op **ret_ops, Dwarf_Signed *ret_opcnt,
	 Dwarf_Error *error);

DESCRIPTION

     Function dwarf_expand_frame_instructions() translates DWARF frame instruction bytes into an array of Dwarf_Frame_Op descriptors.

     Argument cie should reference the CIE descriptor associated with the instructions to be translated.

     Arugment instructions should point to an array of frame instruction bytes, as returned by the functions dwarf_get_cie_info(3) or
     dwarf_get_fde_instr_bytes(3).

     Argument len should specify the number of the frame instruction bytes to be translated.

     Argument ret_ops should point to a location that will be set to a pointer to an array of translated Dwarf_Frame_Op descriptors.

     Argument ret_opcnt should point to a location that will hold the total number of the returned descriptors.

     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 descriptor array returned in argument ret_ops is allocated by DWARF Access Library (libdwarf, -ldwarf).  Appli-
     cation code should use function dwarf_dealloc(3) with type DW_DLA_FRAME_BLOCK to free the memory area when the descriptor array is no longer
     needed.

RETURN VALUES

     Function dwarf_expand_frame_instructions() returns DW_DLV_OK when it succeeds.  In case of an error, it returns DW_DLV_ERROR and sets the
     argument err.

ERRORS

     Function dwarf_expand_frame_instructions() can fail with:

     [DW_DLE_ARGUMENT]	One of the arguments cie, instructions, ret_ops or ret_opcnt was NULL.

     [DW_DLE_ARGUMENT]	Argument len was 0.

     [DW_DLE_MEMORY]	An out of memory condition was encountered during the execution of this function.

     [DW_DLE_FRAME_INSTR_EXEC_ERROR]
			An unknown instruction was found in the instruction bytes provided in argument instructions.

EXAMPLE

     To retrieve and expand the frame instructions for a given FDE descriptor, use:

	   Dwarf_Dbg dbg;
	   Dwarf_Cie cie;
	   Dwarf_Fde fde;
	   Dwarf_Ptr fde_inst;
	   Dwarf_Unsigned fde_instlen;
	   Dwarf_Frame_Op *ops;
	   Dwarf_Signed opcnt;
	   Dwarf_Error de;

	   /* ... assuming `dbg` references a valid DWARF debugging context,
	     `fde` references a valid FDE descriptor and `cie` holds the CIE
	     descriptor associated with the FDE descriptor ... */

	   if (dwarf_get_fde_instr_bytes(fde, &fde_inst, &fde_instlen,
	       &de) != DW_DLV_OK)
		   errx(EXIT_FAILURE, "dwarf_get_fde_instr_bytes failed: %s",
		       dwarf_errmsg(de));

	   if (dwarf_expand_frame_instructions(cie, fde_inst, fde_instlen,
	       &ops, &opcnt, &de) != DW_DLV_OK)
		   errx(EXIT_FAILURE,
		       "dwarf_expand_frame_instructions failed: %s",
		       dwarf_errmsg(de));

	   for (i = 0; i < opcnt; i++) {
		   /* ... use ops[i] ... */
	   }

	   /* Free the memory area when no longer needed. */
	   dwarf_dealloc(dbg, ops, DW_DLA_FRAME_BLOCK);

SEE ALSO

     dwarf(3), dwarf_frame_instructions_dealloc(3), dwarf_get_cie_info(3), dwarf_get_cie_index(3), dwarf_get_cie_of_fde, dwarf_get_fde_at_pc(3),
     dwarf_get_fde_info_for_all_regs(3), dwarf_get_fde_info_for_all_regs3(3), dwarf_get_fde_info_for_cfa_reg3(3), dwarf_get_fde_info_for_reg(3),
     dwarf_get_fde_info_for_reg3(3), dwarf_get_fde_instr_bytes(3), dwarf_get_fde_list(3), dwarf_get_fde_list_eh(3), dwarf_get_fde_n(3)

BSD
								 November 9, 2011							       BSD

DWARF_LOCLIST_FROM_EXPR(3)				   BSD Library Functions Manual 				DWARF_LOCLIST_FROM_EXPR(3)

NAME

     dwarf_loclist_from_expr, dwarf_loclist_from_expr_a, dwarf_loclist_from_expr_b -- translate DWARF location expression bytes

LIBRARY

     DWARF Access Library (libdwarf, -ldwarf)

SYNOPSIS

     #include <libdwarf.h>

     int
     dwarf_loclist_from_expr(Dwarf_Debug dbg, Dwarf_Ptr bytes_in, Dwarf_Unsigned bytes_len, Dwarf_Locdesc **llbuf, Dwarf_Signed *listlen,
	 Dwarf_Error *err);

     int
     dwarf_loclist_from_expr_a(Dwarf_Debug dbg, Dwarf_Ptr bytes_in, Dwarf_Unsigned bytes_len, Dwarf_Half addr_size, Dwarf_Locdesc **llbuf,
	 Dwarf_Signed *listlen, Dwarf_Error *err);

     int
     dwarf_loclist_from_expr_b(Dwarf_Debug dbg, Dwarf_Ptr bytes_in, Dwarf_Unsigned bytes_len, Dwarf_Half addr_size, Dwarf_Half offset_size,
	 Dwarf_Small version, Dwarf_Locdesc **llbuf, Dwarf_Signed *listlen, Dwarf_Error *error);

DESCRIPTION

     Function dwarf_loclist_from_expr() translates DWARF location expression bytes into a Dwarf_Locdesc descriptor.  The size for address related
     data is taken to be the default address size for the object being read.

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

     Argument bytes_in should point to an array of DWARF location expression bytes.

     Argument bytes_len should specify the number of the location expression bytes to be translated.

     Argument llbuf should point to a location which will be set to a pointer to a returned Dwarf_Locdesc descriptor.

     Argument listlen should point to a location which will hold the number of the Dwarf_Locdesc descriptors returned.	In this case it is always
     set to 1.

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

     Function dwarf_loclist_from_expr_a() is identical to function dwarf_loclist_from_expr(), except that it requires one additional argument
     addr_size, which specifies the address size to use when translating the location expression bytes.

     Function dwarf_loclist_from_expr_b() is identical to function dwarf_loclist_from_expr_a() except that it requires two additional arguments
     for translating the location expression bytes.  Argument offset_size specifies the offset size, and argument version specifies the DWARF ver-
     sion.  These values are required to correctly translate the DW_OP_GNU_implicit_pointer opcode.

   Memory Management
     The memory area used for the descriptor returned in argument llbuf is allocated by DWARF Access Library (libdwarf, -ldwarf).  When the
     descriptor is no longer needed, application code should use function dwarf_dealloc(3) to free the memory area in two steps:
     1.   First, the array of Dwarf_Loc descriptors pointed to by the ld_s field of the Dwarf_Locdesc descriptor should be deallocated using the
	  allocation type DW_DLA_LOC_BLOCK.
     2.   Next, the application should free the llbuf pointer using the allocation type DW_DLA_LOCDESC.

RETURN VALUES

     On success, these functions returns DW_DLV_OK.  In case of an error, they return DW_DLV_ERROR and set the argument err.

ERRORS

     These functions may fail with the following errors:

     [DW_DLE_ARGUMENT]	    One of the arguments dbg, bytes_in, llbuf or listlen was NULL.

     [DW_DLE_ARGUMENT]	    Argument bytes_len was 0.

     [DW_DLE_ARGUMENT]	    The value of argument addr_size was invalid.

     [DW_DLE_LOC_EXPR_BAD]  An unknown or invalid operation was found in the location expression bytes provided in argument bytes_in.

     [DW_DLE_MEMORY]	    An out of memory condition was encountered during the execution of this function.

SEE ALSO

     dwarf(3), dwarf_dealloc(3), dwarf_loclist_n(3), dwarf_get_fde_info_for_all_regs3(3), dwarf_get_fde_info_for_cfa_reg3(3),
     dwarf_get_fde_info_for_reg3(3), dwarf_get_loclist_entry(3)

BSD
								 December 21, 2014							       BSD