9.2. DWARF Exception Header Encoding

The DWARF Exception Header Encoding is used to describe the type of data used in the .eh_frame_hdr section. The upper 4 bits indicate how the value is to be applied. The lower 4 bits indicate the format of the data.

Table 9-2. DWARF Exception Header value format

NameValueMeaning
DW_EH_PE_omit0xffNo value is present.
DW_EH_PE_uleb1280x01Unsigned value is encoded using the Little Endian Base 128 (LEB128) as defined by DWARF Debugging Information Format.
DW_EH_PE_udata20x02A 2 bytes unsigned value.
DW_EH_PE_udata40x03A 4 bytes unsigned value.
DW_EH_PE_udata80x04An 8 bytes unsigned value.
DW_EH_PE_sleb1280x09Signed value is encoded using the Little Endian Base 128 (LEB128) as defined by DWARF Debugging Information Format.
DW_EH_PE_sdata20x0AA 2 bytes signed value.
DW_EH_PE_sdata40x0BA 4 bytes signed value.
DW_EH_PE_sdata80x0CAn 8 bytes signed value.

Table 9-3. DWARF Exception Header application

NameValueMeaning
DW_EH_PE_absptr0x00Value is used with no modification.
DW_EH_PE_pcrel0x10Value is reletive to the current program counter.
DW_EH_PE_datarel0x30Value is reletive to the beginning of the .eh_frame_hdr section.
DW_EH_PE_omit0xffNo value is present.