To mark when a user of it is known to escape the value. This happens
with materializeForSet arguments which are captured and used in the
write-back. This means we need to keep the context alive until after
the write-back.
Follow-up patches to fully replace the PostponedCleanup hack in SILGen
by a mandatory SIL transformation pass to guarantee the proper lifetime
will use this flag to be more conservative when extending the lifetime.
The problem:
%pa = partial_apply %f(%some_context)
%cvt = convert_escape_to_noescape [not_guaranteed] [escaped] %pa
%ptr = %materialize_for_set(..., %cvt)
... write_back
... // <-- %pa needs to be alive until after write_back
We want to treat arguments to ObjC override and protocol conformance thunks like "call results", since they might be called from ObjC code that doesn't fulfill its nullability promises in practice. Fixes SR-7240 | rdar://problem/38675815.
By using this API, we properly forward ownership when we perform this
conversion. Previously if we had a guaranteed bridged error argument, we would
wrap the bridged error argument in an class existential box and then destroy
that box, violating the +0 contract. Instead now we forward the ownership
correctly through the init_existential_ref.
Found while updating SILGen tests for +0 arguments.
rdar://34222540
Previously, we were not verifying these thunks later in the pipeline. This makes
it harder to track down verifier errors in such thunks. Instead, this PR just
moves the thunk verification to right after we generate the thunk body,
i.e. right after the bad code would have been emitted.
Found while debugging test/SILGen/objc_bridging_any.swift for +0-all-args.
rdar://34222540
- Emit a withoutActuallyEscapingClosure partial apply
This is to convert an @noescape closure to an escaping closure.
This needs to be done in preparation of @noescape closure contexts
becoming trivial.
- Insert escaping to noescape conversions
- Fix SILGen for @noescape
- Postpone closure cleanups to outside the argument scope
- Apply postponement recursively for closures passed to subscripts
- Only skip applying escapeness conversions for Swift thick functions
- Fix parameter convention for noescape closures in thunks
Part of:
SR-5441
rdar://36116691
This has three principal advantages:
- It gives some additional type-safety when working
with known accessors.
- It makes it significantly easier to test whether a declaration
is an accessor and encourages the use of a common idiom.
- It saves a small amount of memory in both FuncDecl and its
serialized form.
I don't think there's a way to test this right now because we don't
actually support SwiftValue and so on except under ObjCInterop, but
it's certainly more future-proof.
at AnyObject?.
Also, ensure that @convention(block) functions can be erased to
AnyObject, and teach SILGen how to do this with unchecked_ref_cast.
Fixes a source compatibility suite regression.
Also, fix some logic in the peephole that was incorrectly recognizing
T? -> U? -> AnyObject as a force instead of a request to create NSNull.
In both cases, we ought to still be able to do much better than the
unpeepholed code by just applying the peephole and then merging in NSNull
in the nil case, but in the short term we need to fix this bug.
Fixes rdar://35402853
This takes a series of ManagedValues and combines them together into 1 tuple. It
assumes that all non-trivial ManagedValues are all at +1 or all at +0. It leaves
the verification to the ownership verifier since this would immediately trigger
the ownership verifier when the instruction is created by the SILBuilder.
rdar://34222540
The bridging function that we are calling here takes in the value to be bridged
at +0. We were storing that value via a normal store. This looks like a double
consume since we were destroying the value later. Now we use a store_borrow.
rdar://29791263
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.
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.
This is in prepatation for splitting getAtUncurryLevel into one function that
returns the CalleeTypeInfo (which is needed early) and a later one that returns
a ManagedValue, which can occur later.
rdar://33358110
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.
Previously we were storing a pointer to the non-yet blockified function and not
cleaning it up. This was safe since we were performing a copy_block on the block
and destroying the SSA value of the non-yet blockified function. This looks like
a double consume to the ownership verifier. To fix this, I changed the bridging
code to use a new entrypoint for storing on SILGenBuilder that just does the
right thing by forwarding the cleanup on the SSA value and transfering it to the
address. This means the address will be destroyed instead of the SSA value,
yielding proper ownership.
rdar://31880847
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.
Only emit calls to Builtin.swift3ImplicitObjCEntrypoint() when we are
in Swift 4 mode with `-enable-swift3-objc-inference`, which is a
transitional state in which one is debugging the use of the
deprecated @objc entrypoints. Fixes rdar://problem/32122408.
NormalProtocolConformance has the only correct implementation of this
functionality. Instead, providing a safer getWitnessDecl() that
doesn't promise substitutions that are incorrect (and not actually
used by any clients).
When a method is dynamic, we always call through the Objective-C
runtime, which leads to a huge number of false positives. Suppress the
runtime calls here.
Introduce a new runtime entry point,
`swift_objc_swift3ImplicitObjCEntrypoint`, which is called from any
Objective-C method that was generated due to `@objc` inference rules
that were removed by SE-0160. Aside from being a central place where
users can set a breakpoint to catch when this occurs, this operation
provides logging capabilities that can be enabled by setting the
environment variable SWIFT_DEBUG_IMPLICIT_OBJC_ENTRYPOINT:
SWIFT_DEBUG_IMPLICIT_OBJC_ENTRYPOINT=0 (default): do not log
SWIFT_DEBUG_IMPLICIT_OBJC_ENTRYPOINT=1: log failed messages
SWIFT_DEBUG_IMPLICIT_OBJC_ENTRYPOINT=2: log failed messages with
backtrace
SWIFT_DEBUG_IMPLICIT_OBJC_ENTRYPOINT=3: log failed messages with
backtrace and abort the process.
The log messages look something like:
***Swift runtime: entrypoint -[t.MyClass foo] generated by
implicit @objc inference is deprecated and will be removed in
Swift 4
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.
