These are tests that fail in the next commit without this flag. This
does not add -verify-ignore-unrelated to all tests with -verify, only
the ones that would fail without it. This is NFC since this flag is
currently a no-op.
When a C enum has multiple constants with the same value, ClangImporter selects one of them to import as an `EnumElementDecl` and imports the others as `VarDecl` “aliases” of that one. This helps preserve the invariant that each case of an enum has a unique raw value and is distinct for exhaustiveness checking.
However, a bug in that logic could sometimes cause the canonical case to be imported *twice*—once as an `EnumElementDecl` and again as a `VarDecl` alias. In this situation, the `EnumElementDecl` was not added to the enum’s member list, resulting in a malformed AST. This bug has apparently been present since early 2017 (!), but it seems to have been harmless until recently, when the `ComputeSideEffects` SIL pass recently became sensitive to it (probably because of either #79872 or #80263).
Correct this problem by modifying the memoization logic to retrieve the canonical case’s clang-side constant so the subsequent check will succeed. Additionally change a variable name and add comments to help clarify this code for future maintainers.
In lieu of adding new unit tests, this commit adds a (slightly expensive) conditional assertion to catch this kind of AST malformation. There are actually about twenty tests that will fail with just the assertion and not the fix, but I’ve updated one of them to enable the assertion even in release mode.
Fixes rdar://148213237. Followup to #80487, which added related assertions to the SIL layer.
Clang Importer strips prefixes from enum and option set case names. The logic to do this computes a common prefix from the type name and all non-deprecated case names (to oversimplify), which means that adding, removing, or changing one case can change the prefix that is removed from *all* cases. This typically causes the prefix to become shorter, meaning that additional words are prepended to each existing case name.
Existing diagnostics make it look like the case has disappeared, when in fact it still exists under a different name. A little more information may help developers to figure out what happened.
Add a tailored diagnostic for this scenario which kicks in when (a) a missing member is diagnosed, (b) the base is an imported enum or option set’s metatype, and (c) an enum case or static property exists which has the name we attempted to look up as a suffix.
Fixes rdar://116251319.
(and similar for flag_enum)
This commit prepares the importer for a world in which NS_ENUM and
NS_OPTIONS have adopted the new Clang attributes 'enum_extensibility'
and 'flag_enum', but API notes are used to reverse the effect. Without
this there would be no transition path for adopting the standard Cocoa
macros, which have applied unconditionally up to now.
rdar://problem/18744821
These new Clang attributes identify whether an enum is intended to
represent an option set or not, and whether the set of cases listed in
the enum declaration is exhaustive. (Swift doesn't currently have a
closed/open distinction for enums, so treat any C enum with
enum_extensibility as a proper closed Swift enum, like we do with
NS_ENUM.)
Enums with neither attribute will continue to be imported as unique
types.
rdar://problem/28476618
Or rather, when the name importer decides that the name it /would/
have should start with a number, and gives up. We should probably
fix that separately, but meanwhile don't crash.
> Roses are red
> Prefix-stripping can create an invalid remainder
> assert(!member->NextDecl &&
> "Already added to a container")
rdar://problem/30401506
...and avoid making aliases from one unavailable declaration to another.
If it's unavailable, we can just import it as a normal case and not
worry about it. This fixes an issue where Sema would try to diagnose
the body of an "alias" for referring to unavailable declarations.
(Background: enum cases in Swift have to have unique values, so we
import any duplicate values as static properties. Pattern matching
logic has a hack to recognize these particular static properties as
being "case-like".)
This commit also sinks enum element uniqueness checking into importing
the enum, instead of keeping a global map we never consult again. This
should save a small bit of memory.
rdar://problem/30025723
