Re: [PATCH] analyzer: Recognize __builtin_free as a matching deallocator

[Jeff Law <jeffreyalaw@gmail.com>]

On 8/25/2021 9:16 AM, Siddhesh Poyarekar wrote:
> On 8/25/21 5:44 PM, Matthias Klose wrote:
>> On 7/28/21 1:44 PM, David Malcolm via Gcc-patches wrote:
>>> On Wed, 2021-07-28 at 10:34 +0530, Siddhesh Poyarekar wrote:
>>>> Recognize __builtin_free as being equivalent to free when passed into
>>>> __attribute__((malloc ())), similar to how it is treated when it is
>>>> encountered as a call.  This fixes spurious warnings in glibc where
>>>> xmalloc family of allocators as well as reallocarray, memalign,
>>>> etc. are declared to have __builtin_free as the free function.
>>>>
>>>>          gcc/analyzer/ChangeLog:
>>>>          * sm-malloc.cc
>>>>          (malloc_state_machine::get_or_create_deallocator): Recognize
>>>>          __builtin_free.
>>>>
>>>>          gcc/testsuite/ChangeLog:
>>>>          * gcc.dg/analyzer/attr-malloc-1.c (compatible_alloc,
>>>>          compatible_alloc2): New extern allocator declarations.
>>>>          (test_9, test_10): New tests.
>>>
>>> Looks good to me, thanks
>>> Dave
>>>
>>>
>>
>>
>> Please could this be backported to all active branches?
>>
>
> Sure, it looks like only gcc11 needs this since malloc attribute 
> matching seems recent.  David, I've never done a backport before, may 
> I just cherry-pick, push and post a [committed] patch on list or does 
> it need to go through review?
In general it's fine to cherry-pick fixes from the mainline to a release 
branch that fix regressions, incorrect code and the like.

This doesn't fall into one of those categories -- but given this is 
limited to the analyzer, I think it's fine to cherry-pick into the 
release branch as long as David is OK with it as well.

jeff