Nested calls to importBaseMemberDecl() subvert its cache and compromise its idempotence, causing the semantic checker to spuriously report ambiguous member lookups when multiple ClangRecordMemberLookup requests are made (e.g., because of an unrelated missing member lookup).
One such scenario is documented as a test case: test/Interop/Cxx/class/inheritance/inherited-lookup-typechecker.swift fails without this patch because of the expected error from the missing member. Meanwhile, test/Interop/Cxx/class/inheritance/inherited-lookup-executable.swift works because it does not attempt to access a missing member.
This patch fixes the issue by only calling importBaseMemberDecl() in the most derived class (where the ClangRecordMemberLookup originated, i.e., not in recursive requests).
As a consequence of my patch, synthesized member accessors in the derived class directly invoke the member from the base class where the member is inherited from, rather than incurring an indirection at each level of inheritance. As such, the synthesized symbol names are different (and shorter). I've taken this opportunity to update the relevant tests to // CHECK for more of the mangled symbol, rather than only the synthesized symbol prefix, for more precise testing and slightly better readability.
rdar://141069984
Don't attempt this optimization if call has number literals.
This is intended to narrowly fix situations like:
```swift
func test<T: FloatingPoint>(_: T) { ... }
func test<T: Numeric>(_: T) { ... }
test(42)
```
The call should use `<T: Numeric>` overload even though the
`<T: FloatingPoint>` is a more specialized version because
selecting `<T: Numeric>` doesn't introduce non-default literal
types.
Helps situations like `1 + {Double, CGFloat}(...)` by inferring
a type for the second operand of `+` based on a type being constructed.
Currently limited to Double and CGFloat only since we need to
support implicit `Double<->CGFloat` conversion.
Helps situations like `1 + CGFloat(...)` by inferring a type for
the second operand of `+` based on a type being constructed.
Currently limited to known integer, floating-point and CGFloat types
since we know how they are structured.
This is already accounted for by `determineBestChoicesInContext`
and reflected in the overall score, which means that we no longer
need to use this in vacuum.
C unions are imported as opaque types. Therefore we have to assume that a union contains a pointer.
This is important for alias analysis to catch escaping pointers via C unions.
Fixes a miscompile.
rdar://141555290
The inclusion of the full diagnostic list (via DiagnosticList.h) in
DiagnosticGroups.h meant that touching any diagnostic caused most of
the world to rebuild, making me sad. Use forward declarations to limit
how much needs to be rebuilt when changing diagnostics.
`std::result_of_t` has been deprecated and replaced with
`std::invoke_result_t`. Update to the newer spelling to avoid the C++17
deprecation warnings when building with a new STL.
