martong marked an inline comment as done.
martong added a comment.
In D62131#1639168 <https://reviews.llvm.org/D62131#1639168>, @balazske wrote:
> Example about how to get wrong things into `NonEquivalentDecls`:
> We want to compare `class C` for structural equivalence in the following
> codes:
>
> class A {}; class B {int i;}; void x(A *); void y(A *); class C { friend
> void x(A *); friend void y(A *); };
>
>
> and
>
> class A {}; class B {int i;}; void x(A *); void y(B *); class C { friend
> void x(A *); friend void y(B *); };
>
>
> The result is false for `C` but the `NonEquivalentDecls` will contain after
> the compare a `void x(A*)`<->`void x(A*)` pair.
>
> The reason is that during the check we encounter first a `A`<->`B` pair
> (iterating over the friends and friend functions, first `y` is encountered
> and a check for `A` and `B` follows). The `B` is recorded as "tentative
> equivalence" to `A`. Then we try to check `A` to `A` (during check of `x`)
> but because there is a "tentative equivalence" with `B` from `A` the check
> returns false (not equivalent). This false result is recorded as a
> (incorrect) non-equivalence of the two `x` functions.
> I want to replace the `DeclsToCheck` and `TentativeEquivalences` with a set
> of `Decl` pairs (like the NonEquivalentDecls) so it will be possible to
> record the same **from** Decl with multiple **to** values. (Is there a reason
> for why there is a `NonEquivalentDecls` cache but not a `EquivalentDecls` or
> simply a cache for result values?)
Yes, this is indeed a problem. But it is independent from the original problem
this patch intends to solve.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D62131/new/
https://reviews.llvm.org/D62131
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
