Start using null-page values as extra inhabitants when laying out single-payload enums that contain class pointers as their payload type. Don't use inhabitants that set the lowest bit, to avoid trampling potential ObjC tagged pointer representations. This means that 'T?' for class type T now has a null pointer representation. Enums with multiple empty cases, as well as nested enums like 'T??', should now have optimal representations for class type T as well.
Note that we don't yet expose extra inhabitants for aggregates that contain heap object references, such as structs with class fields, Swift function types, or class-bounded existentials (even when the existential has no witness tables).
Swift SVN r10061
We need these for dependent-layout generic classes so we know the allocation/deallocation size and alignment. When I figure out ObjC interop with generic subclasses these should move to the rodata so they get handled resiliently by the ObjC runtime, but for generic class bringup this is convenient.
Swift SVN r9249
In the implementation of class-bounded archetypes and existentials, instead of referring to ObjC pointer types and retain/release operations directly, use an 'UnknownRefCountedPtrTy' and 'emitUnknownRetain/Release' functions.
Swift SVN r5619
Add overloads of getFragileTypeInfo and getFunctionType that take a SILType instead of a Swift CanType, and use them where it's easy to do so. Right now they just forward to the CanType versions, but we'll want to do SILType-specific type conversion soon. Clean up some IRGenSILFunction interfaces now that SILFunction carries most of the information IRGen needs intrinsically. No functionality change.
Swift SVN r5141
Emit the deallocObject runtime call inside the deallocating destructor for a heap object, instead of inside swift_release. This will allow for heap objects with known size to directly call fast deallocator entry points and potentially custom deallocators in the future.
Swift SVN r5027
handling non-fixed layouts.
This uncovered a bug where we weren't rounding up the header
size to the element alignment when allocating an array of archetypes.
Writing up a detailed test case for *that* revealed that we were
never initializing the length field of heap arrays. Fixing that
caused a bunch of tests to crash trying to release stuff. So...
I've left this in a workaround state right now because I have to
catch a plane.
Swift SVN r4804
IRGen was generating the exact same signature for the initializing/allocating constructors and destroying/deallocating destructors. Make it do the right thing by typing the initializing constructor as Swift T -> (...) -> T and the destroying destructor as LLVM void(%swift.refcounted*). (This will later change to '%swift.refcounted*(%swift.refcounted*)' pending some irgen/runtime cleanup.)
Swift SVN r3837
Implement ElementAddrInst for lvalue tuples, and implement the AllocArray, IndexAddr, and IntegerValue insts used to lower variadic tuples. (Actually compiling code that uses variadic tuples still requires support for SpecializeInst and generic functions.)
Swift SVN r3781
The test changes are that we're setting a class body on
some types that we weren't before. For some of these,
this is okay; for others, it's more questionable, but
ultimately not *harmful*.
Swift SVN r3746
The principal difficulty here is that we need accessing the
value witness table for a type to be an efficient operation,
but there (obviously) isn't a VWT field for ObjC classes.
Placing this field after the metatype would tend to bloat
metatypes by quite a bit. Placing it before is best, but
it introduces an unfortunate difference between the address
point of a metatype and the address of the global symbol.
That, however, can be fixed with appropriate linker support.
Still, for now this is rather unfortunately over-subtle.
Swift SVN r3307
The motivations here are that (1) the parametric types
that actually need the 'self' argument don't necessarily
all want to do what tuples do and put the VWT relative
to the metatype at some definable offset and (2)
recovering type parameters from the metatype is much
better defined than also hopping some relationship back.
Plus this allows VWTs to be shared across instances of
generic types. Also, I'm going to need to add a VW
that takes a metatype, and consistency seems right here.
If keeping two values live is actually punishing, I
might have to reconsider this. But the VWT is at least
always recoverable from the metatype, so....
I ended up abstracting the thing that GenHeap was doing
in order to save archetypes for arrays, because I
needed it to save metatypes instead of VWTs and because
it really needed abstractin'.
Swift SVN r3096
This is kindof a pain in a few places where the type system
doesn't propagate canonicality. Also, member initializations
are always direct-initializations and so are allowed to use
explicit constructors, which is a hole in our canonicality
tracking. But overall I like the idea of always working
with canonical types.
Swift SVN r2893
This requires us to potentially copy the value witness tables for
generic struct types as part of computing layout, but that's not
the end of the world (although it will rely on a future patch
to split value witnesses out from protocol witness tables).
Oh, and add a value witness for stride, changing Builtin.strideof
to use that.
Swift SVN r2829
in with the new!
Random notes:
1. I had to XFAIL 4 IRGen tests; I'll file radars on them.
2. I preserved SliceStringByte and renamed it StringByteData because
it has some String-specific functionality.
3. There's a small IRGen patch included which fixes a couple of runtime
failures involving generic array new.
Swift SVN r2644
