This is a preliminary refactoring toward emitting generic metadata
instantiation accessors. This will let us stop exporting metadata
template symbols and reference accessors from conformance tables
instead. The latter is required to enable conformances where the
conforming type is resilient.
Decrease the size of nominal type descriptors and make them true-const by relative-addressing the other metadata they need to reference, which should all be included in the same image as the descriptor itself. Relative-referencing string constants exposes a bug in the Apple linker, which crashes when resolving relative relocations to coalesceable symbols (rdar://problem/22674524); work around this for now by revoking the `unnamed_addr`-ness of string constants that we take relative references to. (I haven't tested whether GNU ld or gold also have this problem on Linux; it may be possible to conditionalize the workaround to only apply to Darwin targets for now.)
This reverts commit ccb2de0a39.
Crashes on these tests:
Swift :: Interpreter/class_resilience.swift
Swift :: Interpreter/generic_objc_subclass.swift
Swift :: Interpreter/struct_resilience.swift
This assertion was accidentally removed in the commit below:
<32bd7705bf>
The original purpose of the check was to ensure that unbound generic patterns
are never added to protocol conformance records, only to type metadata records
(where they are present a future implementation of dynamic type
specialization).
We can avoid using a buffer if the global is fixed-size in all
resilience domains that access it directly. This is a more
conservative condition than being fixed-size in all resilience
domains.
This was fixed by Luke Howard as part of some other changes in the
following patch:
<b5880f386b>
After rebasing my fix, I noticed most of it disappeared.
However, it's still worth checking in the tests.
Fixes <rdar://problem/24183374>.
replace ProtocolConformanceTypeKind with TypeMetadataRecordKind
metadata reference does not need to be indirectable
more efficient check for protocol conformances
remove swift_getMangledTypeName(), not needed yet
kill off Remangle.cpp for non-ObjC builds
cleanup
cleanup
cleanup comments
This is the first in a series of patches that fixes some resilience-related
issues with synthesized accessors and materializeForSet.
Previously we maintained two lists of external declarations encountered while
type checking:
- ASTContext::ExternalDefinitions
- TypeChecker::implicitlyDefinedFunctions
The former contained the following:
- Imported nominal types from Clang, so that SILGen can emit witness tables
- Functions and variables with Clang decls, so that IRGen can instruct Clang
to emit them
- Synthesized accessors
The latter contained synthesized functions for derived conformances.
Since the second list was not visible outside Sema, we relied on the Clang
importer to add the type that contained the declaration to the
ExternalDefinitions list. In practice, we only synthesized members of enums
in this manner.
Because of this, SILGenModule::emitExternalDefinitions() had special logic to
skip members of enums, since it would visit them when visiting the enum itself.
Instead, it appears that we can remove implicitlyDefinedFunctions completely,
changing usage sites to add the decl to ExternalDefinitions instead, and
simplify SILGenModule::emitExternalDefinition() a bit in the process.
Also, it looks like we never had Modules appear in ExternalDefinitions, so
assert if those come up instead of skipping them.
Allocate and project the buffer, respectively, adding the
necessary indirection required to handle the size not being
known until runtime.
For now we don't emit alloc_global instructions anywhere;
an upcoming change will add that at the SIL level.
Also I suspect debug info needs some work to handle the
extra indirection, I'll look into this soon.
of associated types in protocol witness tables.
We use the global access functions when the result isn't
dependent, and a simple accessor when the result can be cheaply
recovered from the conforming metadata. Otherwise, we add a
cache slot to a private section of the witness table, forcing
an instantiation per conformance. Like generic type metadata,
concrete instantiations of generic conformances are memoized.
There's a fair amount of code in this patch that can't be
dynamically tested at the moment because of the widespread
reliance on recursive expansion of archetypes / dependent
types. That's something we're now theoretically in a position
to change, and as we do so, we'll test more of this code.
This speculatively re-applies 7576a91009,
i.e. reverts commit 11ab3d537f.
We have not been able to duplicate the build failure in
independent testing; it might have been spurious or unrelated.
of associated types in protocol witness tables.
We use the global access functions when the result isn't
dependent, and a simple accessor when the result can be cheaply
recovered from the conforming metadata. Otherwise, we add a
cache slot to a private section of the witness table, forcing
an instantiation per conformance. Like generic type metadata,
concrete instantiations of generic conformances are memoized.
There's a fair amount of code in this patch that can't be
dynamically tested at the moment because of the widespread
reliance on recursive expansion of archetypes / dependent
types. That's something we're now theoretically in a position
to change, and as we do so, we'll test more of this code.
This reverts commit 6528ec2887, i.e.
it reapplies b1e3120a28, with a fix
to unbreak release builds.
The runtime entry doesn't just report the error, unlike the other report* functions, it also does the crashing.
Reapplying independent of unrelated reverted patches.
This reverts commit b1e3120a28.
Reverting because this patch uses WitnessTableBuilder::PI in NDEBUG code.
That field only exists when NDEBUG is not defined, but now NextCacheIndex, a
field that exists regardless, is being updated based on information from PI.
This problem means that Release builds do not work.
of associated types in protocol witness tables.
We use the global access functions when the result isn't
dependent, and a simple accessor when the result can be cheaply
recovered from the conforming metadata. Otherwise, we add a
cache slot to a private section of the witness table, forcing
an instantiation per conformance. Like generic type metadata,
concrete instantiations of generic conformances are memoized.
There's a fair amount of code in this patch that can't be
dynamically tested at the moment because of the widespread
reliance on recursive expansion of archetypes / dependent
types. That's something we're now theoretically in a position
to change, and as we do so, we'll test more of this code.
If an enum case has a payload but the unsubstituted payload type is
zero-sized, we would convert the case into a no-payload case.
This was valid when the only invariant that had to be preserved
is that an enum's layout is the same between all substitutions
of a generic type.
However this is now wrong if the payload type is resiliently-sized,
because other resilience domains may not have knowledge that it is
zero-sized.
The new utility methods will also be used in class layout.
Decrease the size of nominal type descriptors and make them true-const by relative-addressing the other metadata they need to reference, which should all be included in the same image as the descriptor itself. Relative-referencing string constants exposes a bug in the Apple linker, which crashes when resolving relative relocations to coalesceable symbols (rdar://problem/22674524); work around this for now by revoking the `unnamed_addr`-ness of string constants that we take relative references to. (I haven't tested whether GNU ld or gold also have this problem on Linux; it may be possible to conditionalize the workaround to only apply to Darwin targets for now.)
If a struct has fixed layout but contains fields which are opaque,
or if the struct itself is opaque, use a metadata accessor function
instead of loading the metadata directly.
Let's say that A and B are two structs defined in the same module,
and B has a fixed size. This patch adds support for these two cases:
1) Fixed-layout struct A contains resilient struct B
2) Resilient struct A contains resilient struct B
In case 1),
a) Inside X: A is fixed-size and has constant metadata
i) Direct metadata access can be performed on A and B
ii) Direct field access can be performed on A and B
d) Outside X: B has an opaque layout
i) Metadata accessor must be called for A and B
ii) Fields of A do not have constant offsets, instead the offsets
must be loaded from type metadata
Case 2) is the same as above except ii) does not apply, since fields
of resilient structs are manipulated via accessors.
Eventually, we will use metadata accessor functions for all public
struct and enum types.
John and I discussed this and agreed that we only need two cases here,
not four. In the future this may be merged with ResilienceExpansion,
and become a struct with additional availability information, but
we're definitely sure we don't need four levels here.
Add a new ResilientStructTypeInfo. This is a singleton since
all resilient structs have opaque payloads and are accessed
through value witness tables.
With this in place, flesh out IRGenModule::isResilient() and
use the new singleton to convert resilient structs.
Note that the old isResilient() was hard-coded to report that
all Clang-imported classes are "resilient". Now that this has
been unified with NominalTypeDecl::hasFixedLayout(), we will
report Clang-imported classes are "resilient" at the SIL level.
This should not introduce any semantic differences at this
point.
Unlike SIL, where currently resilient types are always resilient
even when used from the same module, IRGen is able to perform
direct manipulation of resilient structs from the current
module, since IRGen's type lowering has a resilience scope
plumbed through.
Note that we do not yet support laying out structs and classes
containing resilient fields -- this will come in a future patch.
IRGen emits lazily-emitted definitions after emitting Clang declarations.
So an internal function that references an Objective-C class global and
is itself referenced from after a public function can observe
a OBJC_CLASS_$_ global defined by Clang.
Use a similar strategy as the Clang patch, just bitcast the global if it
exists already.
Fixes <rdar://problem/23200656>.
Swift SVN r32845
- GenProto.cpp for protocols and protocol conformances
- GenExistential.cpp for existential type layout and operations
- GenArchetype.cpp for archetype type layout and operations
Swift SVN r32493
