[sheepdog] [PATCH RFC] sheep: remove assert() for better error messages

[MORITA Kazutaka]

At Mon,  1 Oct 2012 22:34:25 +0900,
Hitoshi Mitake wrote:
> 
> diff --git a/include/sd_assert.h b/include/sd_assert.h
> new file mode 100644
> index 0000000..05c553e
> --- /dev/null
> +++ b/include/sd_assert.h
> @@ -0,0 +1,31 @@
> +#ifndef SD_ASSERT_H
> +#define SD_ASSERT_H
> +
> +#include "logger.h"
> +#include "daemonize.h"
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +
> +#ifdef assert
> +#error "don't include assert.h directly"
> +#endif
> +
> +#define assert(expr) do {						\
> +		if (expr)						\
> +			break;						\
> +									\
> +		if (is_daemonized()) {					\
> +			vprintf(SDOG_ERR, "assert: %s:%d: %s: "		\
> +				"Asserting `%s' failed.\n",		\
> +				__FILE__, __LINE__, __func__, #expr);	\
> +		} else {						\
> +			fprintf(stderr, "assert: %s:%d: %s: "		\
> +				"Asserting `%s' failed.\n",		\
> +				__FILE__, __LINE__, __func__, #expr);	\
> +			 }						\
> +									\
> +		abort();						\
> +	} while (0)
> +
> +#endif	/* SD_ASSERT_H */

Some comments:

 - assert() should do nothing when NDEBUG is defined.
 - I think the log level should be SDOG_EMERG rather than SDOG_ERR.
 - How about using vprintf in any case?  vprintf prints message to
   stderr when the program is running in foreground.
 - How about define assert in lib/util.h directly?

Then, I think the definition should be something like the following.

=
#ifdef assert
#undef assert
#endif

#ifdef NDEBUG
#define assert(e)  ((void)0)
#else
#define assert(e)  (!(e) && panic(....))
#endif
==

Thanks,

Kazutaka