Constructors and methods had two parameter lists, one for self and one
for the formal parameters. Destructors only had one parameter list,
which introduced an annoying corner case.
The SILGen testsuite consists of valid Swift code covering most language
features. We use these tests to verify that no unknown nodes are in the
file's libSyntax tree. That way we will (hopefully) catch any future
changes or additions to the language which are not implemented in
libSyntax.
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.
Currently when function types like `(_: Int...) -> Void` are mangled
their names are going to include enclosing sugar BoundGenericType(Array),
which is not necessary and doesn’t play well with `AnyFunctionType::Param`
which strips the sugar away.
Resolves: rdar://problem/34941557
Consider a class hierarchy like the following:
class Base {
func m1() {}
func m2() {}
}
class Derived : Base {
override func m2() {}
func m3() {}
}
The SIL vtable for 'Derived' now records that the entry for m1
is inherited, the entry for m2 is an override, and the entry
for m3 is a new entry:
sil_vtable Derived {
#Base.m1!1: (Base) -> () -> () : _T01a4BaseC2m1yyF [inherited]
#Base.m2!1: (Base) -> () -> () : _T01a7DerivedC2m2yyF [override]
#Derived.m3!1: (Derived) -> () -> () : _T01a7DerivedC2m3yyF
}
This additional information will allow IRGen to emit the vtable
for Derived resiliently, without referencing the symbol for
the inherited method m1() directly.
Erasing the block directly from its parent using bb->eraseFromParent() doesn't update SILGenFunction's internal state tracking the postmatter section of the function. Fixes SR-1333 | rdar://problem/33351098.
With the option -sil-print-debuginfo the printing of debug locations and scopes can be enabled.
I made the default for the option “false”, because in 99% of the time I don’t need the debug info in the printed SIL and I prefer better readability.
I put in a simple fixup pass (MarkUninitializedFixup) for staging purposes. I
don't expect it to be in tree long. I just did not feel comfortable fixing up in
1 commit all of the passes up to DI.
rdar://31521023
The goal here is to make the short demangling as short and readable as possible, also at the cost of omitting some information.
The assumption is that whenever the short demangling is displayed, there is a way for the user to also get the full demangled name if needed.
*) omit <where ...> because it does not give useful information anyway
Deserializer.deserialize<A where ...> () throws -> [A]
--> Deserializer.deserialize<A> () throws -> [A]
*) for multiple specialized functions only emit a single “specialized”
specialized specialized Constructible.create(A.Element) -> Constructible<A>
--> specialized Constructible.create(A.Element) -> Constructible<A>
*) Don’t print function argument types:
foo(Int, Double, named: Int)
--> foo(_:_:named:)
This is a trade-off, because it can lead to ambiguity if there are overloads with different types.
*) make contexts of closures, local functions, etc. more readable by using “<a> in <b>” syntax
This is also done for the full and not only for the simplified demangling.
Renderer.(renderInlines([Inline]) -> String).(closure #1)
--> closure #1 in Renderer.renderInlines
*) change spacing, so that it matches our coding style:
foo <A> (x : A)
--> foo<A>(x: A)
We used to give witness thunks public linkage if the
conforming type and the protocol are public.
This is completely unnecessary. If the conformance is
fragile, the thunk should be [shared] [serialized],
allowing the thunk to be serialized into callers after
devirtualization.
Otherwise for private protocols or resilient modules,
witness thunks can just always be private.
This should reduce the size of compiled binaries.
There are two other mildly interesting consequences:
1) In the bridged cast tests, we now inline the witness
thunks from the bridgeable conformances, which removes
one level of indirection.
2) This uncovered a flaw in our accessibility checking
model. Usually, we reject a witness that is less
visible than the protocol; however, we fail to
reject it in the case that it comes from an
extension.
This is because members of an extension can be
declared 'public' even if the extended type is not
public, and it appears that in this case the 'public'
keyword has no effect.
I would prefer it if a) 'public' generated a warning
here, and b) the conformance also generated a warning.
In Swift 4 mode, we could then make this kind of
sillyness into an error. But for now, live with the
broken behavior, and add a test to exercise it to ensure
we don't crash.
There are other places where this "allow public but
ignore it, kinda, except respect it in some places"
behavior causes problems. I don't know if it was intentional
or just emergent behavior from general messiness in Sema.
3) In the TBD code, there is one less 'failure' because now
that witness thunks are no longer public, TBDGen does not
need to reason about them (except for the case #2 above,
which will probably require a similar workaround in TBDGen
as what I put into SILGen).
This generalizes a hack where re-abstraction thunks become fragile on contact
with fragile functions.
The old policy was:
- [fragile] functions always serialized
- [reabstraction_thunk] transitively referenced from fragile always serialized
The new policy is:
- [serialized] functions always serialized
- [serializable] functions transitively referenced from serialized functions
are always serialized
- Most kinds of thunks can now be [serializable], allowing them to be shared
between serialized and non-serialized code without any issues, as long as the
body of the thunk is sufficiently "simple" (doesn't reference private
symbols or performs direct access to resilient types)
This changes the order in which declarations are emitted.
It also means we no longer emit a vtable entry for the
materializeForSet of dynamic storage. Neither of these are
intended to have any functional effect.
This is in preparation for removing the +0 self hack.
This commit in more detail does the following:
1. It adds Formal Evaluation Scopes to certain places where the scopes were
missing. Specifically:
a. The SILGenLValue cases are places where we are invoking accessors. In each
one of these cases, we had a formal evaluation scope in the accessor
itself, but we did not have a scope that closed over the base access and
the accessor access. The base access is a formal evaluation in the sense
that just like with inout bases, we must create a new reference to the
base and re-destroy the base in a chain of accesses. This is to ensure
that we do not extend the lifetime of the base inappropriately.
b. The SILGenPoly case is a place where we have never properly placed a
Formal Evaluation Scope and have completely been relying on the +0 self
hack to make sure that archetype callees are properly destroyed
immediately after a +0 call.
2. It changes all of the places in SILGen that emit self to using formal access
cleanups instead of normal cleanups.
rdar://29791263
Everything here should be NFC after the ownership model eliminator except for 1
change where translation of unowned parameters is made more
correct. Specifically:
1. In manageParam, we make it so that if we allow PlusZero, we begin an actual
begin_borrow, end_borrow sequence. We can do this unconditionally since if the
passed in SILValue is already borrowed, we just return early.
2. In TranslateArguments::translateSingle(), we used to handle owned, unowned,
and guaranteed parameters all the same way. This is of course incorrect. Now we
do the following:
a. If our final translated value is guaranteed, but we want an unowned or
owned parameter, then we perform a copyUnmanaged().
b. If our final translated value is unowned and our argument must be a
guaranteed value, then we first transition the unowned value to an owned value
using SILGen::emitManagedRetain() and then transition from owned to guaranteed
using a emitBeginBorrow().
c. If our final translated value is owned and our argument must be a
guaranteed value, then we perform an emitBeginBorrow().
3. In forwardFunctionArguments(), if our argument requires a guaranteed
argument, we begin a begin borrow sequence.
rdar://29791263
Textual SIL was sometimes ambiguous when SILDeclRefs were used, because the textual representation of SILDeclRefs was the same for functions that have the same name, but different signatures.
Textual SIL was sometimes ambiguous when SILDeclRefs were used, because the textual representation of SILDeclRefs was the same for functions that have the same name, but different signatures.
Officially kick SILBoxType over to be "nominal" in its layout, with generic layouts structurally parameterized only by formal types. Change SIL to lower a capture to a nongeneric box when possible, or a box capturing the enclosing generic context when necessary.
Use a syntax that declares the layout's generic parameters and fields,
followed by the generic arguments to apply to the layout:
{ var Int, let String } // A concrete box layout with a mutable Int
// and immutable String field
<T, U> { var T, let U } <Int, String> // A generic box layout,
// applied to Int and String
// arguments
Keep in mind that these are approximations that will not impact correctness
since in all cases I ensured that the SIL will be the same after the
OwnershipModelEliminator has run. The cases that I was unsure of I commented
with SEMANTIC ARC TODO. Once we have the verifier any confusion that may have
occurred here will be dealt with.
rdar://28685236
Recently I changed the ArchetypeBuilder is minimize requirements
in generic signatures. However substitution lists still contained
all recursively-expanded nested types.
With recursive conformances, this list becomes potentially
infinite, so we can't expand it out anymore. Also, it is just
a waste of time to have them there.
This ensures that ownership is properly propagated forward through the use-def
graph.
This was the work that was stymied by issues relating to SILBuilder performing
local ARC dataflow. I ripped out that local dataflow in 6f4e2ab and added a
cheap ARC guaranteed dataflow pass that performs the same optimization.
Also in the process of doing this work, I found that there were many SILGen
tests that were either pattern matching in the wrong functions or had wrong
CHECK lines (for instance CHECK_NEXT). I fixed all of these issues and also
expanded many of the tests so that they verify ownership. The only work I left
for a future PR is that there are certain places in tests where we are using the
projection from an original value, instead of a copy. I marked those with a
message SEMANTIC ARC TODO so that they are easy to find.
rdar://28685236
