midl /char { signed | unsigned | ascii7 }
midl /char signed filename.idl
midl /char unsigned filename.idl
midl /char ascii7 filename.idl
The /char switch helps you ensure that the MIDL compiler and C compiler operate together correctly for all char and small types. By definition, MIDL char is unsigned. Small is defined in terms of char (#define small char), and MIDL small is signed.
The /char switch directs the MIDL compiler to specify explicit signed or unsigned declarations in the generated files when the C-compiler sign declaration conflicts with the MIDL default for that type.
The following table summarizes the generated types:
| midl /char option | Generated char type | Generated small type |
|---|---|---|
| midl /char signed | unsigned char | small |
| midl /char unsigned | char | signed small |
| midl /char ascii7 | char | small |
The /char signed option indicates that the C-compiler char type is signed. To match the MIDL default for char, the MIDL compiler must convert all uses of char not accompanied by a sign specification to unsigned char. The small type is not modified because this C-compiler default matches the MIDL default for small.
The /char unsigned option indicates that the C-compiler char type is unsigned. The MIDL compiler converts all uses of small not accompanied by a sign specification to signed small.
The ascii7 option indicates that no explicit sign specification is added to char types. The type small is generated as small.
To avoid confusion, you should use explicit sign specifications for char and small types whenever possible in the IDL file. Note that the use of explicitly signed char types in your IDL file is not supported by DCE IDL. Therefore, this feature is not available when you compile with the MIDL /osf switch.
For more information related to /char, see small.
char, General MIDL Command-line Syntax, /osf, small