[PATCH] D48474: [analyzer][ctu] fix unsortable diagnostics

[Rafael Stahl via Phabricator via cfe-commits]

r.stahl added a comment.

In https://reviews.llvm.org/D30691#879838, @xazax.hun wrote:

> In https://reviews.llvm.org/D30691#878830, @r.stahl wrote:
>
> > For my purposes I replaced the return statement of the compareCrossTUSourceLocs function with:
> >
> >   return XL.getFileID() < YL.getFileID();
> >
> >
> > A more correct fix would create only one unique diagnostic for both cases.
>
>
> Thank you for the report, I could reproduce this after modifying the null dereference checker. My fear of using file IDs is that I don't know whether they are stable. So in subsequent runs, different paths might be chosen by the analyzer and this could be confusing to the user.  I will think about a workaround that both stable and solves this assertion.
>
> I see two possible ways to do the proper fix. One is to check explicitly for this case when the same function appears in multiple translation units. A better approach would be to have the ASTImporter handle this case. I think the proper fix is better addressed in a separate patch.


Here is my improper fix with test case. Since CTU is still an experimental feature and this is a rare case to encounter I believe it's okay to risk confusing the user, rather than keep it broken.

Unfortunately I will not have the time to work on a proper fix.


Repository:
  rC Clang

https://reviews.llvm.org/D48474