PING 3 [PATCH] fix up compute_objsize (including PR 103143)

[Martin Sebor]

Ping:
https://gcc.gnu.org/pipermail/gcc-patches/2021-November/583735.html

On 11/22/21 9:41 AM, Martin Sebor wrote:
> Ping:
> https://gcc.gnu.org/pipermail/gcc-patches/2021-November/583735.html
> 
> On 11/15/21 9:49 AM, Martin Sebor wrote:
>> Ping for the following cleanup patch:
>> https://gcc.gnu.org/pipermail/gcc-patches/2021-November/583735.html
>>
>> On 11/8/21 7:34 PM, Martin Sebor wrote:
>>> The pointer-query code that implements compute_objsize() that's
>>> in turn used by most middle end access warnings now has a few
>>> warts in it and (at least) one bug.  With the exception of
>>> the bug the warts aren't behind any user-visible bugs that
>>> I know of but they do cause problems in new code I've been
>>> implementing on top of it.  Besides fixing the one bug (just
>>> a typo) the attached patch cleans up these latent issues:
>>>
>>> 1) It moves the bndrng member from the access_ref class to
>>>     access_data.  As a FIXME in the code notes, the member never
>>>     did belong in the former and only takes up space in the cache.
>>>
>>> 2) The compute_objsize_r() function is big, unwieldy, and tedious
>>>     to step through because of all the if statements that are better
>>>     coded as one switch statement.  This change factors out more
>>>     of its code into smaller handler functions as has been suggested
>>>     and done a few times before.
>>>
>>> 3) (2) exposed a few places where I fail to pass the current
>>>     GIMPLE statement down to ranger.  This leads to worse quality
>>>     range info, including possible false positives and negatives.
>>>     I just spotted these problems in code review but I haven't
>>>     taken the time to come up with test cases.  This change fixes
>>>     these oversights as well.
>>>
>>> 4) The handling of PHI statements is also in one big, hard-to-
>>>     follow function.  This change moves the handling of each PHI
>>>     argument into its own handler which merges it into the previous
>>>     argument.  This makes the code easier to work with and opens it
>>>     to reuse also for MIN_EXPR and MAX_EXPR.  (This is primarily
>>>     used to print informational notes after warnings.)
>>>
>>> 5) Finally, the patch factors code to dump each access_ref
>>>     cached by the pointer_query cache out of pointer_query::dump
>>>     and into access_ref::dump.  This helps with debugging.
>>>
>>> These changes should have no user-visible effect and other than
>>> a regression test for the typo (PR 103143) come with no tests.
>>> They've been tested on x86_64-linux.
>>>
>>> Martin
>>
>