PING 2 [PATCH] fix up compute_objsize (including PR 103143)

[Martin Sebor <msebor@gmail.com>]

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
>