SILWitnessTable::Entry already contains a superset of what was supported
by SILDefaultWitnessTable::Entry, the latter of which only had “no entry”
and “method” states. Make SILDefaultWitnessTable::Entry an alias for
SILWitnessTable::Entry, and unify all of the parsing/printing/
(de)serialization logic.
* Introduce stored inlinable function bodies
* Remove serialization changes
* [InterfaceGen] Print inlinable function bodies
* Clean up a little bit and add test
* Undo changes to InlinableText
* Add serialization and deserialization for inlinable body text
* Allow parser to parse accessor bodies in interfaces
* Fix some tests
* Fix remaining tests
* Add tests for usableFromInline decls
* Add comments
* Clean up function body printing throughout
* Add tests for subscripts
* Remove comment about subscript inlinable text
* Address some comments
* Handle lack of @objc on Linux
...instead of std::vector, which (1) will always make separate
allocations, and (2) has features and overhead we don't need
I don't expect this to actually affect performance too much, but it
seems more correct for what Serialization needs anyway.
Not everything that goes into the "identifier table" is actually an
Identifier. If we don't need the string to be uniqued in the
ASTContext, don't bother calling getIdentifier.
May save some memory usage (and a string table lookup) for
deserialization.
serialization::BitOffset is set up for being in a PointerUnion, but in
this case that's not just overkill but actually wasteful, since we
have an extra flag to pack in. Use a raw bitfield instead.
No functionality change.
The recovery logic was erronously kicking in, because it was comparing
the substituted underlying type with the declaration's underlying type.
For a generic typealias, these never equal, so instead, serialize the
unsubstituted type, and substitute it in deserialization.
This does not eliminate the entrypoints on SILBuilder yet. I want to do this in
two parts so that it is functionally easier to disentangle changing the APIs
above SILBuilder and changing the underlying instruction itself.
rdar://33440767
Most of this patch is just removing special cases for materializeForSet
or other fairly mechanical replacements. Unfortunately, the rest is
still a fairly big change, and not one that can be easily split apart
because of the quite reasonable reliance on metaprogramming throughout
the compiler. And, of course, there are a bunch of test updates that
have to be sync'ed with the actual change to code-generation.
This is SR-7134.
Previously SILModule contained two different pathways for the deserializer to
send notifications that it had created functions:
1. A list of function pointers that were called when a function's body was
deserialized. This was added recently so that access enforcement elimination is
run on newly deserialized SIL code if we have already eliminated access
enforcement from the module.
2. SILModule::SerializationCallback. This is an implementation of the full
callback interface and is used by the SILModule to update linkage and other
sorts of book keeping.
To fix the pass manager notification infrastructure, I need to be able to send
notifications to a SILPassManager when deserializing. I also need to be able to
eliminate these callbacks when a SILPassManager is destroyed. These requirements
are incompatible with the current two implementations since: (2) is an
implementation detail of SILModule and (1) only notifies on function bodies
being deserialized instead of the creation of new declarations (what the caller
analysis wants).
Rather than adding a third group of callbacks, this commit refactors the
infrastructure in such a way that all of these use cases can use one
implementation. This is done by:
1. Lifting the interface of SerializedSILLoader::Callback into a base
notification protocol for deserialization called
DeserializationNotificationHandlerBase and its base no-op implementation into an
implementation of the aforementioned protocol:
DeserializationNotificationHandler.
2. Changing SILModule::SerializationCallback to implement
DeserializationNotificationHandler.
3. Creating a class called FunctionBodyDeserializationNotificationHandler that
takes in a function pointer and uses that to just override the
didDeserializeFunctionBody. This eliminates the need for the specific function
body deserialization list.
4. Replacing the state associated with the two other pathways with a single
DeserializationNotificationHandlerSet class that contains a set of
DeserializationNotificationHandler and chains notifications to them. This set
implements DeserializationNotificationHandlerBase so we know that its
implementation will always be in sync with DeserializationNotificationHandler.
rdar://42301529
ConvertFunction and reabstraction thunks need this attribute. Otherwise,
there is no way to identify that withoutActuallyEscaping was used
to explicitly perform a conversion.
The destination of a [without_actually_escaping] conversion always has
an escaping function type. The source may have either an escaping or
@noescape function type. The conversion itself may be a nop, and there
is nothing distinctive about it. The thing that is special about these
conversions is that the source function type may have unboxed
captures. i.e. they have @inout_aliasable parameters. Exclusivity
requires that the compiler enforce a SIL data flow invariant that
nonescaping closures with unboxed captures can never be stored or
passed as an @escaping function argument. Adding this attribute allows
the compiler to enforce the invariant in general with an escape hatch
for withoutActuallyEscaping.
Instead of serializing the input type of a function type, which is a
TupleType or ParenType, serialize the individual parameters instead.
This means that we no longer need to serialize TupleTypes or
ParenTypes with custom flags, nor do we ever serialize standalone
InOutTypes, so all of that can be removed.
We can recover function, destructor, constructor, enum element
and subscript types from their parameter types and result type
(if present), by calling the AST's various computeType()
methods.
These methods don't do any more work than would be done if
we had deserialized the type and reconstructed it, so let's
just recompute it instead.
Note that we still serialize a ton of function types, due
to XREFs.
With my build configuration, this reduces the size of
Swift.swiftmodule by 237KiB (out of 20MiB).
SILFunctions no longer have a GenericParamList, so all of these
circularity and ordering problems are gone.
We *do* deserialize the generic parameters before creating decls
that have them though, so serialize generic parameters as if
their DeclContext was the DeclContext of the owner decl.
This is what we do when we parse generic parameters too; in
both cases, the constructor for the owner decl gives the
generic parameters the right DeclContext.
This allows us to dump it in the generated interface, though it's
still not syntax-highlighted. This is necessary for textual module
interfaces, but it's also just a longstanding request for Xcode's
"Generated Interface" / "Jump to Definition" feature.
rdar://problem/18675831
Way back in 6afe77d597 Chris removed the 'Parameter' type that tracked
extra information about parameters, collapsing it into ParamDecl and
making ParameterList "an overblown array of ParamDecl*'s". Do the same
thing for Serialization: push the few fields tracked in
PARAMETERLIST_ELT records down into PARAM_DECL, and then simplify the
PARAMETERLIST record to directly reference its parameters.
No functionality change.
We previously shied away from this in order to not /accidentally/
depend on it, but it becomes interesting again with textual
interfaces, which can certainly be read by humans. The cross-file
order is the order of input files, which is at least controllable by
users.
For now, the accessors have been underscored as `_read` and `_modify`.
I'll prepare an evolution proposal for this feature which should allow
us to remove the underscores or, y'know, rename them to `purple` and
`lettuce`.
`_read` accessors do not make any effort yet to avoid copying the
value being yielded. I'll work on it in follow-up patches.
Opaque accesses to properties and subscripts defined with `_modify`
accessors will use an inefficient `materializeForSet` pattern that
materializes the value to a temporary instead of accessing it in-place.
That will be fixed by migrating to `modify` over `materializeForSet`,
which is next up after the `read` optimizations.
SIL ownership verification doesn't pass yet for the test cases here
because of a general fault in SILGen where borrows can outlive their
borrowed value due to being cleaned up on the general cleanup stack
when the borrowed value is cleaned up on the formal-access stack.
Michael, Andy, and I discussed various ways to fix this, but it seems
clear to me that it's not in any way specific to coroutine accesses.
rdar://35399664
The other side of #17404. Since we don't want to generate up front key path metadata for properties/subscripts with no withheld implementation details, the client should generate a key path component that can be used to represent a key path component based on its public interface.
The storage kind has been replaced with three separate "impl kinds",
one for each of the basic access kinds (read, write, and read/write).
This makes it far easier to mix-and-match implementations of different
accessors, as well as subtleties like implementing both a setter
and an independent read/write operation.
AccessStrategy has become a bit more explicit about how exactly the
access should be implemented. For example, the accessor-based kinds
now carry the exact accessor intended to be used. Also, I've shifted
responsibilities slightly between AccessStrategy and AccessSemantics
so that AccessSemantics::Ordinary can be used except in the sorts of
semantic-bypasses that accessor synthesis wants. This requires
knowing the correct DC of the access when computing the access strategy;
the upshot is that SILGenFunction now needs a DC.
Accessor synthesis has been reworked so that only the declarations are
built immediately; body synthesis can be safely delayed out of the main
decl-checking path. This caused a large number of ramifications,
especially for lazy properties, and greatly inflated the size of this
patch. That is... really regrettable. The impetus for changing this
was necessity: I needed to rework accessor synthesis to end its reliance
on distinctions like Stored vs. StoredWithTrivialAccessors, and those
fixes were exposing serious re-entrancy problems, and fixing that... well.
Breaking the fixes apart at this point would be a serious endeavor.
We sometimes serialized the “isObjC” state, and sometimes not. When we did serialize it,
we rarely used the bit for anything. Serialize it for all declarations where it makes
sense, and consistently call setIsObjC() with the deserialized value.
The major important thing here is that by using copy_unowned_value we can
guarantee that the non-ownership SIL ARC optimizer will treat the release
associated with the strong_retain_unowned as on a distinc rc-identity from its
argument. As an example of this problem consider the following SILGen like
output:
----
%1 = copy_value %0 : $Builtin.NativeObject
%2 = ref_to_unowned %1
%3 = copy_unowned_value %2
destroy_value %1
...
destroy_value %3
----
In this case, we are converting a strong reference to an unowned value and then
lifetime extending the value past the original value. After eliminating
ownership this lowers to:
----
strong_retain %0 : $Builtin.NativeObject
%1 = ref_to_unowned %0
strong_retain_unowned %1
strong_release %0
...
strong_release %0
----
From an RC identity perspective, we have now blurred the lines in between %3 and
%1 in the previous example. This can then result in the following miscompile:
----
%1 = ref_to_unowned %0
strong_retain_unowned %1
...
strong_release %0
----
In this case, it is possible that we created a lifetime gap that will then cause
strong_retain_unowned to assert. By not lowering copy_unowned_value throughout
the SIL pipeline, we instead get this after lowering:
----
strong_retain %0 : $Builtin.NativeObject
%1 = ref_to_unowned %0
%2 = copy_unowned_value %1
strong_release %0
...
strong_release %2
----
And we do not miscompile since we preserved the high level rc identity
pairing.
There shouldn't be any performance impact since we do not really optimize
strong_retain_unowned at the SIL level. I went through all of the places that
strong_retain_unowned was referenced and added appropriate handling for
copy_unowned_value.
rdar://41328987
**NOTE** I am going to remove strong_retain_unowned in a forthcoming commit. I
just want something more minimal for cherry-picking purposes.
Cross-references are identified by their containing module, with the
assumption that two modules will never have the same name. However, an
overlay has the same name as its underlying Clang module, which means
that there can be two declarations with the same name, the same type,
and the same module name. This is the underlying cause of the
'UIEdgeInsetsZero' problem, but it also affects the CloudKit overlay.
By tracking a bit that just says "this came from Clang", we're able
to resolve otherwise ambiguous cross-references.
(Why didn't we do it this way all along? Because if a declaration
moves from Clang to Swift or vice versa, that would break the
cross-reference. But that's only interesting if the swiftmodule format
is meant to be persistent across changing dependencies, and it looks
like we're moving away from that anyway. It's also a little weird for
SerializedModuleLoader to have special cases for Clang, but this isn't
the first.)
Note that I'm not reverting the UIEdgeInsetsZero workaround here; the
end state will have that coming just from UIKit as originally
described.
rdar://problem/40839486
Wire up the request-evaluator with an instance in ASTContext, and
introduce two request kinds: one to retrieve the superclass of a class
declaration, and one to compute the type of an entry in the
inheritance clause.
Teach ClassDecl::getSuperclass() to go through the request-evaluator,
centralizing the logic to compute and extract the superclass
type.
Fixes the crasher from rdar://problem/26498438.
Introduce some metaprogramming of accessors and generally prepare
for storing less-structured accessor lists.
NFC except for a change to the serialization format.
This can only happen in one case today: a module imports a bridging
header, but the header on disk has disappeared, and now we need to
fall back to the (often inadequate) version that's stored inside the
swiftmodule file. Even if the module fails to load, the bridging
header has already been imported, and so anything else that happens
might still emit diagnostics and need that text to be alive, which
means we need to keep the buffer alive too.
This flag supports promoting KeyPath access violations to an error in
Swift 4+, while building the standard library in Swift 3 mode. This is
only necessary as long as the standard library continues to build in
Swift 3 mode. Once the standard library build migrates, it can all be
ripped out.
<rdar://problem/40115738> [Exclusivity] Enforce Keypath access as an error, not a warning in 4.2.
This reverts commit bb16ee049d,
reversing changes made to a8d831f5f5.
It's not sufficient to solve the problem, and the choices were to do
something more complicated, or just take a simple brute force
approach. We're going with the latter.
This can't arise from a clean build, but it can happen if you have
products lingering in a search path and then either rebuild one of
the modules in the cycle, or change the search paths.
The way this is implemented is for each module to track whether its
imports have all been resolved. If, when loading a module, one of its
dependencies hasn't resolved all of its imports yet, then we know
there's a cycle.
This doesn't produce the best diagnostics, but it's hard to get into
this state in the first place, so that's probably okay.
https://bugs.swift.org/browse/SR-7483
Mandatory pass will clean it up and replace it by a copy_block and
is_escaping/cond_fail/release combination on the %closure in follow-up
patches.
The instruction marks the dependence of a block on a closure that is
used as an 'withoutActuallyEscaping' sentinel.
rdar://39682865
Convert NameAliasType’s internal representation from tail-allocating an
array of Substitutions (to be treated as a SubstitutionList) to store a
single SubstitutionMap. Serialize using that SubstitutionMap.
Allow substitution maps to be serialized directly (via an ID), writing out
the replacement types and conformances as appropriate. This is a more
efficient form of serialization than the current SubstitutionList approach,
because it maintains uniqueness of substitution maps within a module file,
and is a step toward eliminating SubstitutionList entirely.
