The handling of SIL box types in both deserialization and in the SIL
parser assumed that the number of substitutions in the box type would
be equivalent to the number of generic parameters. This assumption is
incorrect when the generic signature adds requirements to an
associated type.
Fixes rdar://problem/29740594.
Deserializing a generic environment can involve the type checker
(because it can cause the Clang importer to deserialize more), so we
cannot safely be completely lazy about a deserialized generic
environment if, e.g., SILGen or the AST verifier refers to
it. Therefore, implement a basic "pending actions" infrastructure so
that we will force the complete deserialization of any
lazily-deserialized generic environments when the outermost
deserialization of that ModuleFile occurs. This gives us the internal
laziness we need to wire up generic environments without being truly
lazy across compilation phases.
Fixes rdar://problem/29741827.
Fixes SR-2757.
Variables in capture lists are treated as 'let' constants, which can
result in misleading, incorrect diagnostics. Mark them as such in order
to produce better diagnostics, by adding an extra parameter to the
VarDecl initializer.
Alternatively, these variables could be marked as implicit, but that
results in other diagnostic problems: capture list variables that are
never used produce warnings, but these warnings aren't normally emitted for
implicit variables. Other assertions in the compiler also misfire when
these variables are treated as implicit.
Another alternative would be to walk up the AST and determine whether
the `VarDecl`, but there doesn't appear to be a way to do so.
This "fixes" two issues:
- The name of a non-public typealias would leak into the public
interface if the extension had any public members.
- A common pattern of defining a platform-specific typealias for an
imported class and then extending that type would lead to
circularity when trying to deserialize the typealias. We /shouldn't/
be loading the extension at that point, but fixing that would be
much harder.
The "right" answer is to (a) check that the typealias is public if the
extension has any public members, and (b) somehow ensure there is no
circularity issue (either by not importing the extension as a result
of importing the typealias, or by the extension being able to set its
sugared base type later).
rdar://problem/29694978
- The DeclContext versions of these methods have equivalents
on the DeclContext class; use them instead.
- The GenericEnvironment versions of these methods are now
static methods on the GenericEnvironment class. Note that
these are not made redundant by the instance methods on
GenericEnvironment, since the static methods can also be
called with a null GenericEnvironment, in which case they
just assert that the type is fully concrete.
- Remove some unnecessary #includes of ArchetypeBuilder.h
and GenericEnvironment.h. Now changes to these files
result in a lot less recompilation.
[semantic-sil] Add ValueOwnershipKind field to SILPHIArgument and split Argument creation methods into one for SILPHIArgument and another for SILFunctionArgument.
We preserve the current behavior of assuming Any ownership always and use
default arguments to hide this change most of the time. There are asserts now in
the SILBasicBlock::{create,replace,insert}{PHI,Function}Argument to ensure that
the people can only create SILFunctionArguments in entry blocks and
SILPHIArguments in non-entry blocks. This will ensure that the code in tree
maintains the API distinction even if we are not using the full distinction in
between the two.
Once the verifier is finished being upstreamed, I am going to audit the
createPHIArgument cases for the proper ownership. This is b/c I will be able to
use the verifier to properly debug the code. At that point, I will also start
serializing/printing/parsing the ownershipkind of SILPHIArguments, but lets take
things one step at a time and move incrementally.
In the process, I also discovered a CSE bug. I am not sure how it ever worked.
Basically we replace an argument with a new argument type but return the uses of
the old argument to refer to the old argument instead of a new argument.
rdar://29671437
For a long time, we have:
1. Created methods on SILArgument that only work on either function arguments or
block arguments.
2. Created code paths in the compiler that only allow for "function"
SILArguments or "block" SILArguments.
This commit refactors SILArgument into two subclasses, SILPHIArgument and
SILFunctionArgument, separates the function and block APIs onto the subclasses
(leaving the common APIs on SILArgument). It also goes through and changes all
places in the compiler that conditionalize on one of the forms of SILArgument to
just use the relevant subclass. This is made easier by the relevant APIs not
being on SILArgument anymore. If you take a quick look through you will see that
the API now expresses a lot more of its intention.
The reason why I am performing this refactoring now is that SILFunctionArguments
have a ValueOwnershipKind defined by the given function's signature. On the
other hand, SILBlockArguments have a stored ValueOwnershipKind. Rather than
store ValueOwnershipKind in both instances and in the function case have a dead
variable, I decided to just bite the bullet and fix this.
rdar://29671437
When deserializing a SIL generic environment, don't form generic type
parameter declarations that would have empty names; they print poorly
(as <anonymous>), breaking SIL parsing of the result.
Changes:
* Terminate all namespaces with the correct closing comment.
* Make sure argument names in comments match the corresponding parameter name.
* Remove redundant get() calls on smart pointers.
* Prefer using "override" or "final" instead of "virtual". Remove "virtual" where appropriate.
Serialization of the requirement-to-synthetic-environment map was
walking in DenseMap order. However, the keys to this map are
known---they're always the generic parameters of the requirement. So,
walk those generic parameters to make it deterministic, and don't
bother serializing them because they're known to the deserializer
already.
Fixes rdar://problem/29689811.
Serialize generic environments via a generic environment ID with a
separte offset table, so we have identity for the generic environments
and will share generic environments on deserialization.
- TypeAliasDecl::getAliasType() is gone. Now, getDeclaredInterfaceType()
always returns the NameAliasType.
- NameAliasTypes now always desugar to the underlying type as an
interface type.
- The NameAliasType of a generic type alias no longer desugars to an
UnboundGenericType; call TypeAliasDecl::getUnboundGenericType() if you
want that.
- The "lazy mapTypeOutOfContext()" hack for deserialized TypeAliasDecls
is gone.
- The process of constructing a synthesized TypeAliasDecl is much simpler
now; instead of calling computeType(), setInterfaceType() and then
setting the recursive properties in the right order, just call
setUnderlyingType(), passing it either an interface type or a
contextual type.
In particular, many places weren't setting the recursive properties,
such as the ClangImporter and deserialization. This meant that queries
such as hasArchetype() or hasTypeParameter() would return incorrect
results on NameAliasTypes, which caused various subtle problems.
- Finally, add some more tests for generic typealiases, most of which
fail because they're still pretty broken.
The substitution only replaces archetypes with abstract generic parameters, so no conformance lookup is necessary, and we can provide a "lookup" callback now that just vends abstract conformances.
(Ideally, we'd be able to do this for mapTypeIntoContext too, but we run into problems with generic signatures with same-type constraints on associated types with protocol requirements. Mapping `t_0_0.AssocType` into such a context will require conformance lookup for the concrete type replacement, since same-type Requirements don't preserve the conformances that satisfy the protocol requirements for the same-type relationship.)
This was in the first high level ARC instruction proposal, but I have not needed
it until now. The use case for this is to ahandle strong_retain_unowned (which
takes in an unowned value, asserts it is still alive, performs a strong_retain,
and returns the @owned value). This @owned value needs a destroy_value.
rdar://29671437
This simplifies the SILType substitution APIs and brings them in line with Doug and Slava's refactorings to improve AST-level type substitution. NFC intended.
When deserializing the generic environment for a generic type, only
immediately deserialize the generic signature. The generic environment
will be deserialized later, when it's needed.
When we deserialize a function that has a generic environment, set the
generic signature and a key to allow lazy creation of the generic
environment. Because most clients won't need the generic environment,
this lets us avoid creating generic environments.
We were only setting the “requires class” bit when it was true. When it was false, semantic analysis would end up taking the slow path to compute the “false”, which is wasted effort.
When a pattern within a type context is serialized, serialize its
interface type (not its contextual type). When deserializing, record
the interface type and keep a side table of the associated
DeclContext, so that we can lazily map to the contextual type on first
access. This is designed to break recursion when we change the way
archetypes and generic environments are serialized.
Only serialize the interface types of parameter declarations into the
module file, then lazily build the contextual types when
requested. This saves a small amount of space in the Swift module
files (~64k for the Swift standard library) and some effort on load.
First, ensure all ParamDecls that are synthesized from scratch are given
both a contextual type and an interface type.
For ParamDecls written in source, add a new recordParamType() method to
GenericTypeResolver. This calls setType() or setInterfaceType() as
appropriate.
Interestingly enough a handful of diagnostics in the test suite have
improved. I'm not sure why, but I'll take it.
The ParamDecl::createUnboundSelf() method is now only used in the parser,
and no longer sets the type of the self parameter to the unbound generic
type. This was wrong anyway, since the type was always being overwritten.
This allows us to remove DeclContext::getSelfTypeOfContext().
Also, ensure that FuncDecl::getBodyResultTypeLoc() always has an interface
type for synthesized declarations, eliminating a mapTypeOutOfContext()
call when computing the function interface type in configureInterfaceType().
Finally, clean up the logic for resolving the DynamicSelfType. We now
get the interface or contextual type of 'Self' via the resolver, instead
of always getting the contextual type and patching it up inside
configureInterfaceType().
This was made redundant by typed boxes, and the type operand was already removed from textual SIL, but the field was never removed from the instruction's in memory representation. It becomes wrong in the face of compound boxes with layout.
A pointless use of polymorphism -- the result values are not
interchangeable in any practical sense:
- For GenericTypeParamDecls, this returned getDeclaredInterfaceType(),
which is an interface type.
- For AssociatedTypeDecls, this returned the sugared AssociatedTypeType,
which desugars to an archetype.
- For TypeAliasDecls, this returned TypeAliasDecl::getAliasType(),
which desugars to a type containing archetypes.
- For NominalTypeDecls, this returned NominalTypeDecl::getDeclaredType(),
which is the unbound generic type, a special case used for inferring
generic arguments when they're not written in source.
This eliminates the really gross registration of archetype builders
within the ASTContext, and is another little step toward lazily
constructing archetypes.
Stop recording specific archetypes anywhere in
PotentialArchetype. Instead, use a GenericEnvironment to record/query
the archetype that corresponds to that PotentialArchetype, making it
possible to use the same archetype builder (and its potential
archetypes) to build multiple generic environments.
