We need to borrow guaranteed values with sil ownership and need to
distinguish between @callee_guaranteed and other context conventions in
a few places.
SR-5441
rdar://33255593
Support for @noescape SILFunctionTypes.
These are the underlying SIL changes necessary to implement the new
closure capture ABI.
Note: This includes a change to function name mangling that
primarily affects reabstraction thunks.
The new ABI will allow stack allocation of non-escaping closures as a
simple optimization.
The new ABI, and the stack allocation optimization, also require
closure context to be @guaranteed. That will be implemented as the
next step.
Many SIL passes pattern match partial_apply sequences. These all
needed to be fixed to handle the convert_function that SILGen now
emits. The conversion is now needed whenever a function declaration,
which has an escaping type, is passed into a @NoEscape argument.
In addition to supporting new SIL patterns, some optimizations like
inlining and SIL combine are now stronger which could perturb some
benchmark results.
These underlying SIL changes should be merged now to avoid conflicting
with other work. Minor benchmark discrepancies can be investigated as part of
the stack-allocation work.
* Add a noescape attribute to SILFunctionType.
And set this attribute correctly when lowering formal function types to SILFunctionTypes based on @escaping.
This will allow stack allocation of closures, and unblock a related ABI change.
* Flip the polarity on @noescape on SILFunctionType and clarify that
we don't default it.
* Emit withoutActuallyEscaping using a convert_function instruction.
It might be better to use a specialized instruction here, but I'll leave that up to Andy.
Andy: And I'll leave that to Arnold who is implementing SIL support for guaranteed ownership of thick function types.
* Fix SILGen and SIL Parsing.
* Fix the LoadableByAddress pass.
* Fix ClosureSpecializer.
* Fix performance inliner constant propagation.
* Fix the PartialApplyCombiner.
* Adjust SILFunctionType for thunks.
* Add mangling for @noescape/@escaping.
* Fix test cases for @noescape attribute, mangling, convert_function, etc.
* Fix exclusivity test cases.
* Fix AccessEnforcement.
* Fix SILCombine of convert_function -> apply.
* Fix ObjC bridging thunks.
* Various MandatoryInlining fixes.
* Fix SILCombine optimizeApplyOfConvertFunction.
* Fix more test cases after merging (again).
* Fix ClosureSpecializer. Hande convert_function cloning.
Be conservative when combining convert_function. Most of our code doesn't know
how to deal with function type mismatches yet.
* Fix MandatoryInlining.
Be conservative with function conversion. The inliner does not yet know how to
cast arguments or convert between throwing forms.
* Fix PartialApplyCombiner.
Now that the GenericSignatureBuilder is no longer sensitive to the input
module, stop uniquing the canonical GSBs based on that module. The main
win here is when deserializing a generic environment: we would end up
creating a canonical GSB in the module we deserialized and another
canonical GSB in the module in which it is used.
Implement a module-agnostic conformance lookup operation within the GSB
itself, so it does not need to be supplied by the code constructing the
generic signature builder. This makes the generic signature builder
(closer to) being module-agnostic.
This replaces the '[volatile]' flag. Now, class_method and
super_method are only used for vtable dispatch.
The witness_method instruction is still overloaded for use
with both ObjC protocol requirements and Swift protocol
requirements; the next step is to make it only mean the
latter, also using objc_method for ObjC protocol calls.
Once we compute a generic signature from a generic signature builder,
all queries involving that generic signature will go through a separate
(canonicalized) builder, and the original builder can no longer be used.
The canonicalization process then creates a new, effectively identical
generic signature builder. How silly.
Once we’ve computed the signature of a generic signature builder, “register”
it with the ASTContext, allowing us to move the existing generic signature
builder into place as the canonical generic signature builder. The builder
requires minimal patching but is otherwise fully usable.
Thanks to Slava Pestov for the idea!
Funnel all places where we create a generic signature builder to compute
the generic signature through a single entry point in the GSB
(`computeGenericSignature()`), and make `finalize` and `getGenericSignature`
private so no new uses crop up.
Tighten up the signature of `computeGenericSignature()` so it only works on
GSB rvalues, and ensure that all clients consider the GSB dead after that
point by clearing out the internal representation of the GSB.
Funnel all places where we create a generic signature builder to compute
the generic signature through a single entry point in the GSB
(`computeGenericSignature()`), and make `finalize` and `getGenericSignature`
private so no new uses crop up.
Tighten up the signature of `computeGenericSignature()` so it only works on
GSB rvalues, and ensure that all clients consider the GSB dead after that
point by clearing out the internal representation of the GSB.
Once we compute a generic signature from a generic signature builder,
all queries involving that generic signature will go through a separate
(canonicalized) builder, and the original builder can no longer be used.
The canonicalization process then creates a new, effectively identical
generic signature builder. How silly.
Once we’ve computed the signature of a generic signature builder, “register”
it with the ASTContext, allowing us to move the existing generic signature
builder into place as the canonical generic signature builder. The builder
requires minimal patching but is otherwise fully usable.
Thanks to Slava Pestov for the idea!
Funnel all places where we create a generic signature builder to compute
the generic signature through a single entry point in the GSB
(`computeGenericSignature()`), and make `finalize` and `getGenericSignature`
private so no new uses crop up.
Tighten up the signature of `computeGenericSignature()` so it only works on
GSB rvalues, and ensure that all clients consider the GSB dead after that
point by clearing out the internal representation of the GSB.
Emit a borrow scope whenever exploding tuples in to a list of arguments.
I spent a lot of time attempting to refactor the reabstraction thunk generation
code with code that handles RValue. However, there is a subtle difference in how
tuples are handled when they are packed into a single "RValue" as opposed to a
list of arguments.
Eventually, I ditched that effort because of subtle complexity and fell back on
Michael's suggestion of handling the extra thunk-sepcific work inside
Scope.popPreservingValues. This will just go away though once we have the
'destructure' instruction.
Use the ManagedValue forms of the SILInstruction constructors
where possible. This ensures that after emitting an instruction
such as an upcast, we rewrite the value's cleanup to destroy
the new value, and not the old value. This is important because
the ownership verifier asserts that instructions dominated by
a destroy cannot use the destroyed value.
Should be NFC, since the ownership verifier is off by default
for now.
This is already an RValue invariant that used to be enforced upon RValue
construction. We put in a hack to work around a bug where that was not occuring
and changed RValue constructors to instead load stored objects when they needed
to. But the problem is that since then we have added more constructors that
provide other manners to create such an invalid RValue.
I added verification to many parts of RValue and exposed an additional verify
method that we can invoke at the end of emitRValue() eventually to verify our
invariants. This will give me the comfort to make that assumption in other parts
of SILGen without worry.
I also performed a small amount of cleanup of RValue construction.
rdar://33358110
The allocating thunk handles the `dynamic`-ness of the initializing entry point, which maps to an underlying `-initWith*:` ObjC method, and cannot itself be treated as `dynamic`. Fixes SR-5223 | rdar://problem/32778104.
These instructions have the same semantics as the *ExistentialAddr instructions
but operate directly on the existential value, not its address.
This is in preparation for adding ExistentialBoxValue instructions.
The previous name would cause impossible confusion with "opaque existentials"
and "opaque existential boxes".
ground work for the syntactic bridging peephole.
- Pass source and dest formal types to the bridging routines in addition
to the dest lowered type. The dest lowered type is still necessary
in order to handle non-standard abstraction patterns for the dest type.
- Change bridging abstraction patterns to store bridged formal types
instead of the formal type.
- Improve how SIL type lowering deals with import-as-member patterns.
- Fix some AST bugs where inadequate information was being stored in
various expressions.
- Introduce the idea of a converting SGFContext and use it to regularize
the existing id-as-Any conversion peephole.
- Improve various places in SILGen to emit directly into contexts.
In anticipation of removing this bit, move it from the
recursive type property into TupleType - its only real
user. This necessitates uglifying a bit of logic in the
short term that used to speak broadly of materializability
to instead speak about LValues and Tuples of InOut values
independently.
through a few places.
This patch should be NFC for existing patterns, but it's preparing for
using SILGen's built-in bridging capabilities for more things.
The GenericSignatureBuilder requires `finalize()` to be called before a
generic signature can be retrieved with `getGenericSignature()`. Most of the former isn’t strictly needed unless you want a generic signature, and the
latter is potentially expensive. `computeGenericSignature()` combines the two
operations together, since they are conceptually related. Update most of the
callers to the former two functions to use `computeGenericSignature()`.
Replace `NameOfType foo = dyn_cast<NameOfType>(bar)` with DRY version `auto foo = dyn_cast<NameOfType>(bar)`.
The DRY auto version is by far the dominant form already used in the repo, so this PR merely brings the exceptional cases (redundant repetition form) in line with the dominant form (auto form).
See the [C++ Core Guidelines](https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#es11-use-auto-to-avoid-redundant-repetition-of-type-names) for a general discussion on why to use `auto` to avoid redundant repetition of type names.
SubstitutionMap::lookupConformance() would map archetypes out
of context to compute a conformance path. Do the same thing
in SubstitutionMap::lookupSubstitution().
The DenseMap of replacement types in a SubstitutionMap now
always has GenericTypeParamTypes as keys.
This simplifies some code and brings us one step closer to
a more efficient representation of SubstitutionMaps.
ExistentialLayout::getProtocols() can return an interior
pointer if the layout describes a single protocol type.
In this case we must not hold on to the result after
the layout goes out of scope.
Fix a few places where this was happening, which should
address a test failure we've been seeing.
Fixes <rdar://problem/31586433>.
Also, add a third [serializable] state for functions whose bodies we
*can* serialize, but only do so if they're referenced from another
serialized function.
This will be used for bodies synthesized for imported definitions,
such as init(rawValue:), etc, and various thunks, but for now this
change is NFC.
