CODEWITHSUNDEEP
ctypedefc-preprocessor
bob.sacamento
bob.sacamento

Reputation: 6661

Confusing syntax in a C typedef

Was hoping someone could help me decipher this C snippet:

typedef int (DEFCALL *getFieldVal)(int key, int fieldSelect, char *name)

DEFCALL is defined earlier in the code, but only as

#define DEFCALL

So, I think DEFCALL is just a blank, and I am effectively looking at

typedef int (*getFieldVal)(int key, int fieldSelect, char *name)

which defines getFieldVal as a pointer to a function that takes args int, int, and char*, and returns an integer. But the DEFCALL has me wondering. Wanted to be sure.

Upvotes: 1

Views: 78

Answers (2)

Dave Rager
Dave Rager

Reputation: 8160

The typedef is defining a function pointer type. The DEFCALL is a preprocessor macro that may be defined to specify any platform specific calling convention information used by the function. In this case it is defined as nothing resulting in the compiler generating the default calling convention, usually cdecl.

Upvotes: 4

Kerrek SB
Kerrek SB

Reputation: 477650

The macro leaves room for adding a calling convention to the function type.

Upvotes: 6

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