Manual Pages  — DWARF_ADD_FRAME_FDE

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

Argument fde should reference a frame descriptor allocated using dwarf_new_fde(3).

Argument die is ignored by this implementation of the DWARF Access Library (libdwarf, -ldwarf)

Argument cie specifies the index of call frame common information entry for the frame descriptor. Valid indices are those returned by the function dwarf_add_frame_cie(3).

Argument symbol_index specifies the ELF symbol index of the first symbol to be used for relocation.

The meaning of the arguments virt_addr, code_len and offset_from_end_sym depend on the value of argument end_symbol_index:

• If the argument end_symbol_index is zero, the argument virt_addr specifies the relocatable address of the start of the function associated with the frame descriptor, the argument code_len specifies the size in bytes of the machine instructions for this function, the argument symbol_index specifies the ELF symbol to be used for relocating the address in argument virt_addr, and the argument offset_from_end_symbol is ignored.
• If the argument end_symbol_index is non-zero, it specifies the ELF symbol index of the second symbol to be used for relocation. In this case, the argument virt_addr specifies an offset from the relocatable symbol specified by argument symbol_index, the argument offset_from_end_symbol should specify an offset from the symbol named by the argument end_symbol_index, and the argument code_len will be ignored. The DW_DLC_SYMBOLIC_RELOCATIONS flag should also have been set on the DWARF producer instance.

  Application code can retrieve the relocation entries for the symbol pair by calling function dwarf_get_relocation_info(3). The relocation entry for the first symbol will have type dwarf_drt_first_of_length_pair and the relocation entry for the second symbol will have type dwarf_drt_second_of_length_pair.

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

Function dwarf_add_frame_fde() is similar to function dwarf_add_frame_fde_b() except that it supports only one relocation symbol.