Decls with a package access level are currently set to public SIL
linkages. This limits the ability to have more fine-grained control
and optimize around resilience and serialization.
This PR introduces a separate SIL linkage and FormalLinkage for
package decls, pipes them down to IRGen, and updates linkage checks
at call sites to include package linkage.
Resolves rdar://121409846
First, "can have an absence of Copyable" is a rather confusing notion,
so the query is flipped to "can be Copyable". Next, it's more robust to
ask if a conformance exists for the TypeDecl to answer that question,
rather than trying to replicate what happens within that conformance
lookup.
Also renames `TypeDecl::isEscapable` to match.
I've renamed the method to `TypeDecl::isNoncopyable`, because the query
doesn't make sense for many other kinds of `ValueDecl`'s beyond the
`TypeDecl`'s. In fact, it looks like no one was relying on that anyway.
Thus, we now have a distinction where in Sema, you ask whether
a `Type` or `TypeDecl` is "Noncopyable". But within SIL, we still
preserve the notion of "move-only" since there is additionally the
move-only type wrapper for types that otherwise support copying.
Deserialization is calling AccessMarkerElimination repeatedly on the
same function.
The bug was introduced here:
commit 872bf40e17
Date: Mon Aug 13 10:24:20 2018
[sil-optimizer] Centralize how we send out serialization notifications.
Where the code that uniques the deserialization callbacks was simply
removed!
As a result, this pass was being invoked a number of times equal to
the number of functions in the module *multiplied* by the number of
functions being deserialized.
Fixes rdar://117141871 (Building spends most of its time in
AccessMarkerElimination)
- VTableSpecializer, a new pass that synthesizes a new vtable per each observed concrete type used
- Don't use full type metadata refs in embedded Swift
- Lazily emit specialized class metadata (LazySpecializedClassMetadata) in IRGen
- Don't emit regular class metadata for a class decl if it's generic (only emit the specialized metadata)
- Add a flag to the serialized module (IsEmbeddedSwiftModule)
- Check on import that the mode matches (don't allow importing non-embedded module in embedded mode and vice versa)
- Drop TBD support, it's not expected to work in embedded Swift for now
- Drop auto-linking backdeploy libraries, it's not expected to backdeploy embedded Swift for now
- Drop prespecializations, not expected to work in embedded Swift for now
- Use CMO to serialize everything when emitting an embedded Swift module
- Change SILLinker to deserialize/import everything when importing an embedded Swift module
- Add an IR test for importing modules
- Add a deserialization validation test
Moving the query implementation up to the AST library from SIL will allow
conveniences to be written on specific AST element classes. For instance, this
will allow `EnumDecl` to expose a convenience that enumerates element decls
that are available during lowering.
Also, improve naming and documentation for these queries.
Reformatting everything now that we have `llvm` namespaces. I've
separated this from the main commit to help manage merge-conflicts and
for making it a bit easier to read the mega-patch.
This is phase-1 of switching from llvm::Optional to std::optional in the
next rebranch. llvm::Optional was removed from upstream LLVM, so we need
to migrate off rather soon. On Darwin, std::optional, and llvm::Optional
have the same layout, so we don't need to be as concerned about ABI
beyond the name mangling. `llvm::Optional` is only returned from one
function in
```
getStandardTypeSubst(StringRef TypeName,
bool allowConcurrencyManglings);
```
It's the return value, so it should not impact the mangling of the
function, and the layout is the same as `std::optional`, so it should be
mostly okay. This function doesn't appear to have users, and the ABI was
already broken 2 years ago for concurrency and no one seemed to notice
so this should be "okay".
I'm doing the migration incrementally so that folks working on main can
cherry-pick back to the release/5.9 branch. Once 5.9 is done and locked
away, then we can go through and finish the replacement. Since `None`
and `Optional` show up in contexts where they are not `llvm::None` and
`llvm::Optional`, I'm preparing the work now by going through and
removing the namespace unwrapping and making the `llvm` namespace
explicit. This should make it fairly mechanical to go through and
replace llvm::Optional with std::optional, and llvm::None with
std::nullopt. It's also a change that can be brought onto the
release/5.9 with minimal impact. This should be an NFC change.
When `-unavailable-decl-optimization=complete` is specified obsolete decls
should be preserved because their symbols are still ABI since they are
available to use when targeting deployment targets earlier than the obsoletion
version.
Resolves rdar://110268649
When `-unavailable-decl-optimization=complete` is specified, exclude
unavailable enum cases from the runtime layout of enums with payloads. Without
this, the type metadata for unavailable types may be referenced by enum cases
with unavailable payloads and cause linker failures.
Resolves rdar://107483852
When `-unavailable-decl-optimization=stub` is specified, insert a call to
`_diagnoseUnavailableCodeReached()` at the beginning of the function to cause
it to trap if executed at run time.
Part of rdar://107388493
I've also fixed this so that it should work on instructions that
define multiple values. Someday we'll change all the open_existential
instructions to produce different values for the type dependency and
the value result; today is not that day, though.
Instead of setting the parent pointer to null, set the `lastInitializedBitfieldID` to -1.
This allows to keep the parent block information, even when an instruction is removed from it's list.
The definition of `Lowering::usesObjCAllocator()` was previously implemented in SILGen, which does not match the library membership of the declaration. The implementation of `SILSymbolVisitor` in the SIL library uses this and since SIL is a dependency of SILGen instead of vice-versa this resulted in a linker error.
Specifically, we get an additional table like thing called sil_moveonlydeinit. It looks as follows:
sil_moveonlydeinit TYPE {
@FUNC_NAME
}
It always has a single entry.
Snapshots are copies of a function at a given point in time.
Currently it's only used for running passes repeatedly for performance profiling.
In future it can be used for caching when doing lazy evaluation in the pipeline.
As we do with field indices for struct instructions.
This avoids quadratic behavior in case of enums with lots of cases.
Also: cache field and enum case indices in the SILModule.
The main point of this change is to make sure that a shared function always has a body: both, in the optimizer pipeline and in the swiftmodule file.
This is important because the compiler always needs to emit code for a shared function. Shared functions cannot be referenced from outside the module.
In several corner cases we missed to maintain this invariant which resulted in unresolved-symbol linker errors.
As side-effect of this change we can drop the shared_external SIL linkage and the IsSerializable flag, which simplifies the serialization and linkage concept.
PublicCMOSymbols stores symbols which are made public by cross-module-optimizations.
Those symbols are primarily stored in SILModule and eventually used by TBD generation and validation.
The functions in llvm-project `AttributeList` have been
renamed/refactored to help remove uses of `AttributeList::*Index`.
Update to use these new functions where possible. There's one use of
`AttrIndex` remaining as `replaceAttributeTypeAtIndex` still takes the
index and there is no `param` equivalent. We could add one locally, but
presumably that will be added eventually.
Leaks checking is not thread safe and e.g. lldb creates multiple SILModules in multiple threads, which would result in false alarms.
Ideally we would make it thread safe, e.g. by putting the instruction counters in the SILModule, but this would be a big effort and it's not worth doing it. Leaks checking in the frontend's and SILOpt's SILModule (not including SILModules created for module interface building) is a good enough test.
rdar://84688015
This was a relict from the -sil-serialize-all days. This linkage doesn't make any sense because a private function cannot be referenced from another module (or file, in case of non-wmo compilation).
It's not needed anymore with delayed instruction deletion.
It was used for two purposes:
1. For analysis, which cache instructions, to avoid dangling instruction pointers
2. For passes, which maintain worklists of instructions, to remove a deleted instructions from the worklist. This is now done by checking SILInstruction::isDeleted().
When an instruction is "deleted" from the SIL, it is put into the SILModule::scheduledForDeletion list.
The instructions in this list are eventually deleted for real in SILModule::flushDeletedInsts(), which is called by the pass manager after each pass run.
In other words: instruction deletion is deferred to the end of a pass.
This avoids dangling instruction pointers within the run of a pass and in analysis caches.
Note that the analysis invalidation mechanism ensures that analysis caches are invalidated before flushDeletedInsts().
In theory we could map opened archetypes per module because opened archetypes _should_ be unique across the module.
But currently in some rare cases SILGen re-uses the same opened archetype in multiple functions.
The fix is to add the SILFunction to the map's key.
That also requires that we update the map whenever instructions are moved from one function to another.
This fixes a compiler crash.
rdar://76916931
Instead, put the archetype->instrution map into SIlModule.
SILOpenedArchetypesTracker tried to maintain and reconstruct the mapping locally, e.g. during a use of SILBuilder.
Having a "global" map in SILModule makes the whole logic _much_ simpler.
I'm wondering why we didn't do this in the first place.
This requires that opened archetypes must be unique in a module - which makes sense. This was the case anyway, except for keypath accessors (which I fixed in the previous commit) and in some sil test files.
