Re: [PATCH 2/3] git-compat: introduce BUG_ON(condition, fmt, ...) macro

From: Jonathan Nieder <jrnieder@gmail.com>
Date: Nov 22, 2017, 23:02 UTC
Message-ID: <20171122230239.GG11671@aiede.mtv.corp.google.com>
In-Reply-To: <20171122223827.26773-3-sbeller@google.com>

Hi,

Stefan Beller wrote:

Show 14 quoted lines

> --- a/git-compat-util.h
> +++ b/git-compat-util.h
> @@ -1092,9 +1092,13 @@ static inline int regexec_buf(const regex_t *preg, const char *buf, size_t size,
>  __attribute__((format (printf, 3, 4))) NORETURN
>  void BUG_fl(const char *file, int line, const char *fmt, ...);
>  #define BUG(...) BUG_fl(__FILE__, __LINE__, __VA_ARGS__)
> +#define BUG_ON(condition, ...) do { if (condition) BUG(__VA_ARGS__); } while (0)
>  #else
>  __attribute__((format (printf, 1, 2))) NORETURN
>  void BUG(const char *fmt, ...);
> +
> +__attribute__((format (printf, 2, 3)))
> +void BUG_ON(int condition, const char *fmt, ...);
>  #endif

I worry that these definitions are mildly incompatible: the macro accepts anything that can go in an 'if', including pointers, and the function only accepts an int.

Is there a way for the macro to typecheck that its argument is an integer to avoid that?

Thanks, Jonathan