Re: [PATCH v2] util/qemu-option: Document the get_opt_value() function

[Markus Armbruster]

Richard Henderson <richard.henderson@linaro.org> writes:

> On 6/29/20 12:08 AM, Philippe Mathieu-Daudé wrote:
>> Coverity noticed commit 950c4e6c94 introduced a dereference before
>> null check in get_opt_value (CID1391003):
>> 
>>   In get_opt_value: All paths that lead to this null pointer
>>   comparison already dereference the pointer earlier (CWE-476)
>> 
>> We fixed this in commit 6e3ad3f0e31, but relaxed the check in commit
>> 0c2f6e7ee99 because "No callers of get_opt_value() pass in a NULL
>> for the 'value' parameter".
>> 
>> Since this function is publicly exposed, it risks new users to do
>> the same error again. Avoid that documenting the 'value' argument
>> must not be NULL.
>
> I think we should also add some use of __attribute__((nonnull(...))) to 
> enforce
> this within the compiler.
>
> I recently did this without a qemu/compiler.h QEMU_FOO wrapper within
> target/arm.  But the nonnull option has optional arguments, so it might be
> difficult to wrap in macros.

Do we support building with a compuler that lacks this attribute?