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.
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
C++ only support multiparameter operator[] in C++23 and up. Change the
code to protect such overloaded operators with a C++ language mode
check.
rdar://133539699
The generated header would not compile without these dependencies. Moreover
users probably expect all-public option to be the most permissive filter
including the maximal amount of declarations.
The generated thunks for functions can refer to some internal methods of
their arguments. As a result, those generated thunks should always be
after the definitions of the corresponding argument types. The printer
ordered the declarations by name, and Swift had the convention starting
types with upper case letters and functions with lower case letters.
This naming convention together with the ordering resulted in the
correct ordering in most of the cases. There were a couple of exceptions
when people diverged from the naming conventions or wanted to export
operators. This patch fixes this problem by always ordering type decls
before function decls.
rdar://129276354
