parameters.
The current implementation to judge the similarity of TypeConstraint in
ASTContext::isSameTemplateParameter is problematic, it couldn't handle
the following case:
```C++
template <__integer_like _Tp, C<_Tp> Sentinel>
constexpr _Tp operator()(_Tp &&__t, Sentinel &&last) const {
return __t;
}
```
When we see 2 such declarations from different modules, we would judge
their similarity by `ASTContext::isSame*` methods. But problems come for
the TypeConstraint. Originally, we would profile each argument one by
one. But it is not right. Since the profiling result of `_Tp` would
refer to two different template type declarations. So it would get
different results. It is right since the `_Tp` in different modules
refers to different declarations indeed. So the same declaration in
different modules would meet incorrect our-checking results.
It is not the thing we want. We want to know if the TypeConstraint have
the same expression.
Reviewer: vsapsai, ilya-biryukov
Differential Revision: https://reviews.llvm.org/D129068
When we do profiling in ASTContext::getAutoType, it wouldn't think about
the canonical declaration for the type constraint. It is bad since it
would cause a negative ODR mismatch while we already know the type
constraint declaration is a redeclaration for the previous one. Also it shouldn't be
bad to use the canonical declaration here.
The compiler would judge two concepts is same by their addresses.
However, when we use modules, the addresses wouldn't be the same all the
time since one is parsed in their TU and another is imported in another
TU.
This patch fixes this by using isSameEntity to judge the two concepts.
Reviewed By: rsmith
Differential Revision: https://reviews.llvm.org/D114769
Chuanqi Xu