[PATCH] D117180: [BasicAliasAnalysis] Switch from isMallocOrCallocLikeFn to onlyAccessesInaccessibleMemory

Thu Jan 13 12:41:08 PST 2022

reames added a comment.

In D117180#3241562 <https://reviews.llvm.org/D117180#3241562>, @xbolva00 wrote:

> In D117180#3241552 <https://reviews.llvm.org/D117180#3241552>, @reames wrote:
>
>> In D117180#3241544 <https://reviews.llvm.org/D117180#3241544>, @xbolva00 wrote:
>>
>>> In D117180#3241489 <https://reviews.llvm.org/D117180#3241489>, @reames wrote:
>>>
>>>> Er, you're correct, but WTF?  We consider an operator new "malloc like"?  That's simply wrong on so many levels.
>>>>
>>>> Well, then the original code is buggy.
>>>
>>> Non throwing version of new (which may return null) is malloc like.
>>
>> Please see the C++ specification wording in expr.new paragraph 13.
>>
>> Calls to the replaceable global allocator are not removable unless coming from a new expression.  I don't believe we have enough information in IR today to tell if they're coming from new expressions or not.
>
> Yeah I know and we have many related PRs. Everything related to C++ “new” is a mess.

Agreed.  Strongly.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D117180/new/

https://reviews.llvm.org/D117180