[U-Boot] [PATCH] Add assert() for debug assertions

[V, Aneesh]

On Thu, Jun 23, 2011 at 2:53 AM, Mike Frysinger <vapier at gentoo.org> wrote:
> On Wednesday, June 22, 2011 17:04:49 Simon Glass wrote:
>> +/*
>> + * An assertion is run-time check done in debug mode only. If DEBUG is not
>> + * defined then it is skipped. It does not BUG or halt U-Boot, but tries
>> to + * continue execution in any case. It is hoped that all failing
>> assertions + * are found before release, and after release it is hoped
>> that they don't + * matter. But in any case these failing assertions
>> cannot be fixed with a + * BUG-type reset (which may just do the same
>> assertion again).
>> + */
>> +#define assert(x)    \
>> +     ({ if (!(x)) printf("Assertion failure '%s' %s line %d\n", \
>> +             #x, __FILE__, __LINE__); })
>>  #else
>>  #define debug(fmt,args...)
>>  #define debugX(level,fmt,args...)
>> +#define assert(x)
>>  #endif       /* DEBUG */
>
> the trouble with ifdef magic like this is that errors/warnings can be
> introduced when DEBUG isnt defined, and then only noticed when DEBUG is
> defined.  so how about:

Symbian OS, that had an array of defensive programming features, had two
ASSERT macros:

Something like ASSERT_DEBUG(x) and ASSERT_ALWAYS(x).

ASSERT_DEBUG(x) could be used more liberally because it is compiled out in
production image and ASSERT_ALWAYS(x) could be used in more critical run-time
errors.

My rule of thumb for using these two was this:

1. ASSERT_DEBUG(x) was used for invariant checking, that's for catching errors
that could arise out of programming errors. This was used more liberally in the
code.
2. ASSERT_ALWAYS(x) was used to catch erros due to invalid run-time parameters
that one may not be able to catch during testing.

best regards,
Aneesh