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

[Richard Henderson]

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.


r~