Explanation: Fix a compilation error in the generated reverse interop
header when a nested foreign type is used in a generic context and it is
reexposed to C++.
Issue: rdar://148597079
Risk: Low, the fix is fairly targeted to the affected scenario.
Testing: Added tests to test suite
Reviewer: @egorzhdan
Explanation: Fixes an issue where the generated reverse interop header
would not compile for nested classes when library evolution is turned
off.
Scope: C++ reverse interop for nested classes for non-opaque types.
Issue: rdar://147882976
Risk: Low, the fix is fairly targeted. While it does affect other
(non-nested type) scenarios, those changes are fairly straightforward
making some names fully qualified. Moreover, that is well tested in our
test suite.
Testing: Added tests to test suite
Reviewer: @egorzhdan
PrintAsClang is supposed to emit declarations in the same order regardless of the compiler’s internal state, but we have repeatedly found that our current criteria are inadequate, resulting in non-functionality-affecting changes to generated header content. Add a diagnostic that’s emitted when this happens soliciting a bug report.
Since there *should* be no cases where the compiler fails to order declarations, this diagnostic is never actually emitted. Instead, we test this change by enabling `-verify` on nearly all PrintAsClang tests to make sure they are unaffected.
This did demonstrate a missing criterion that only mattered in C++ mode: extensions that varied only in their generic signature were not sorted stably. Add a sort criterion for this.
To support nested structs, we emit type aliases in the outer class.
Unfortunately, we emitted these type aliases unconditionally, even if
the actualy nested struct was not emitted to the reverse interop header
(due to visibility or the construct being unsupported). This PR fixed
this issue by checking first if the nested entity should be included in
the reverse interop header.
rdar://141688074
It is really involved to change how methods and classes are emitted into
the header so this patch introduces the impression of nested structs
through using statements and still emits the structs themselves as top
level structs. It emits them in their own namespace to avoid name
collisions. This patch also had to change some names to be fully
qualified to avoid some name lookup errors in case of nested structs.
Moreover, nesting level of 3 and above requires C++17 because it relies
on nested namespaces. Only nested structs are supported, not nested
classes.
Since this patch is already started to grow quite big, I decided to put
it out for reviews and plan to address some of the shortcomings in a
follow-up PR.
rdar://118793469
