CODEWITHSUNDEEP
cmacrosc-preprocessor
Constantin
Constantin

Reputation: 8961

Preprocessor macro: Missing parenthesis

I'm using Visual Studio 2013 and trying to write a preprocessor macro, which will check at compile-time if a VERSION is a valid BCD number:

#define VERSION (uint8)0x01u

#if ((VERSION > 0x99u) || ((VERSION & 0x0Fu) > 0x09u))
#error "Invalid version"
#endif

But for some reason VS2013 shows the following message:

error C1012: unmatched parenthesis : missing ')'

I've checked my parenthesis a few times - but it looks right to me. Is there something I'm missing?

Upvotes: 0

Views: 1592

Answers (2)

user743382
user743382

Reputation:

The preprocessor doesn't understand types, so this cannot work. Assuming uint8 is not a macro, this will expand to

#if (((0)0x01u > 0x99u) || (((0)0x01u & 0x0Fu) > 0x09u))

because all identifiers that are left after macro replacement are replaced by zero. This clearly has syntax errors. The error message you're getting seems misleading to me, but the fact that you're getting an error message at all is appropriate.

Do you really need VERSION to have type uint8? If not, you can simply remove the cast.

If you do need to have it as type uint8, you need to write the expression in such a way that it remains valid even if it gets replaced by 0, such as ((uint8)+0x01u).

Upvotes: 3

Sorcrer
Sorcrer

Reputation: 1644

you cannot define macros as #define VERSION (uint8)0x01u

define it as'

#define VERSION 0x01u

Upvotes: 1

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