At the next 4-byte boundary following the method body can be extra method data sections. These method data sections start with a two byte header (1 byte for flags, 1 byte for the length of the actual data) or a 4-byte header (1 byte for flags, and 3 bytes for length of the actual data). The first byte determines the kind of the header, and what data is in the actual section:
| Flag | Value | Description |
|---|---|---|
CorILMethod_Sect_EHTable |
0x1 | Exception handling data. |
CorILMethod_Sect_OptILTable |
0x2 | Reserved, shall be 0. |
CorILMethod_Sect_FatFormat |
0x40 | Data format is of the fat variety, meaning there is a 3-byte length least-significant byte first format. If not set, the header is small with a 1-byte length |
CorILMethod_Sect_MoreSects |
0x80 | Another data section occurs after this current section |
Currently, the method data sections are only used for exception tables (§II.19). The layout of a small exception header structure as is a follows:
| Offset | Size | Field | Description |
|---|---|---|---|
| 0 | 1 | Kind | Flags as described above. |
| 1 | 1 | DataSize | Size of the data for the block, including the header, say n*12+4. |
| 2 | 2 | Reserved | Padding, always 0. |
| 4 | n | Clauses | n small exception clauses (§II.25.4.6). |
The layout of a fat exception header structure is as follows:
| Offset | Size | Field | Description |
|---|---|---|---|
| 0 | 1 | Kind | Which type of exception block is being used |
| 1 | 3 | DataSize | Size of the data for the block, including the header, say n*24+4. |
| 4 | n | Clauses | n fat exception clauses (§II.25.4.6). |