I've fixed a few bugs recently where I had to switch
a getCanonicalType() call to instead use the stronger
GenericSignature::getCanonicalTypeInContext().
Avoid the 'if (genericSig = ...)' dance by adding a new
form of TypeBase::getCanonicalType() which takes a
signature, and if it's null, just falls back to the
standard getCanonicalType().
Take a seat and pour yourself a beer because this is
going to get pretty intense.
Recall that class methods that return 'Self', have a
'self' type of @dynamic_self X or @dynamic_self X.Type,
for some class X, based on if the method is an instance
method or a static method.
The instance type of a metatype is not lowered, and we
preserve DynamicSelfType there. This is required for
correct behavior with the SIL optimizer.
For example if you specialize a function that contains a
'metatype $((T) -> Int, T).Type' SIL instruction or
some other metatype of a structural type containing a
generic parameter, we might end up with something like
'metatype $((@dynamic_self X) -> Int, X).Type'
after substitution, for some class 'X'. Note that the
second occurrence of 'X', is in "lowered position" so
the @dynamic_self did, indeed, get stripped away.
So while *values* of @dynamic_self type don't need to
carry the fact that they're @dynamic_self at the SIL
level, because Sema has inserted all the right casts.
Metatypes do though, because when lowering the 'metatype'
instruction, IRGen has to know to emit the type metadata
from the method's 'self' parameter, and not the static
metadata for the exact class type.
Essentially, 'metatype @dynamic_self X.Type' is
the same as 'value_metatype %self : X.Type', except that
the @dynamic_self type can appear inside other structural
types also, which is something we cannot write in the
AST.
This is all well and good, but when lowering a
SILFunctionType we erase @dynamic_self from the 'self'
parameter type because when you *call* such a function
from another function, you are not necessarily calling
it on your own 'self' value. And if you are, Sema
already emitted the right unchecked downcast there to
turn the result into the right type.
The problem is that the type of an argument (the value
"inside" the function) used to always be identical to
the type of the parameter (the type from "outside" the
function, in the SILFunctionType). Of course this
assumption is no longer correct for static methods,
where the 'self' argument should really have type
@dynamic_self X.Type, not X.Type.
A further complication is closure captures, whose types
can also contain @dynamic_self inside metatypes in other
structural types. We used to erase @dynamic_self from
these.
Both of these are wrong, because if you call a generic
function <T> (T.Type) -> () with a T := @dynamic_self X
substitution (recall that substitutions are written in
terms of AST types and not lowered types) and pass in
the 'self' argument, we would pass in a value of type
X.Type and not @dynamic_self X.Type.
There were similar issues with captures, with
additional complications from nested closures.
Fix all this by having SILGenProlog emit a downcast
to turn the X.Type argument into a value of type
@dynamic_self X.Type, and tweak capture lowering to
not erase @dynamic_self from capture types.
This fixes several cases that used to fail with
asserts in SILGenApply or the SIL verifier, in particular
the example outlined in <rdar://problem/31226650>,
where we would crash when calling a protocol extension
method from a static class method (oops!).
If you got this far and still follow along,
congratulations, you now know more about DynamicSelfType
than I do.
Replace VariadicTuple and NonVariadicTuple with a single Tuple node.
The variadic property is now part of the tuple element and not of the whole tuple.
This fixes a crash while building the Swift standard library when
partial specializations are enabled.
Eventually we should get rid of needing the DeclContext in the mangled
typename at all, and this is one step towards that goal.
rdar://problem/31253373
Add a -verify-debug-info option that invokes dwarfdump --verify as the last step after running dsymutil. dwarfdump is invoked with same options clang 802.0.35 uses to invoke it:
dwarfdump --verify --debug-info --eh-frame --quiet
A warning is produced if -verify-debug-info is set and no debug option is also set.
dwarfdump is failing to validate the debug info in the test verify-debug-info.swift. The failure is:
error: .debug_line[0x0000007d].row[0].file = 1 is not a valid index
https://bugs.swift.org/browse/SR-2396
This replaces SILDeclRef::getBaseOverriddenVTableEntry(). It lives
in the TypeConverter because it needs to use type lowering information
to determine if the method requires a new vtable entry or not.
The general self-derived check doesn't really make sense for
conformance constraints, because we want to distinguish among
different protocol conformances.
Simply mangling the derived method is no longer sufficient. Now also
mangle the base method, so that eventually we handle this sort of
scenario:
class Base {
// introduces: Base.method
func method(_: Int, _: Int) {}
}
class First : Base {
// overrides: Base.method
// introduces: First.method
override func method(_: Int?, _: Int) {}
}
class Second : First {
// overrides: Base.method, First.method
// introduces: Second.method
override func method(_: Int?, _: Int?) {}
}
Here, the override of Base.method by Second.method and the
override of First.method by Second.method require distinct
manglings even though the derived method (Second.method) is
the same in both cases.
Note that while the new mangling is longer, vtable thunks are
always emitted with private linkage, so with the exception of
the standard library which is built with -sil-serialize-all
they will not affect the size of dylibs.
The standard library itself has very few classes so it doesn't
matter there either.
This patch doesn't actually add any support to introduce new
vtable entries for methods that override; this is coming up
next.
In the old vtable emission code, IRGen would skip addressors,
but they had entries in the SILVTable. This is still correct
behavior, so skip addressors explicitly in SILVTableVisitor.
We never call addressors dynamically, only inside a getter,
setter or materializeForSet. When a property with addressors
is overridden we provide new getters and setters (which may
or may not statically dispatch to a peer addressor).
This is a CRTP utility to walk the members of a class and
produce vtable entries. It will be used to clean up some
code duplication between SILGen and IRGen, and to provide
missing functionality for multiple vtable entries per
method.
Flip the polarity of the frontend flag controlling whether TSan treats inout
accesses as conceptual writes. It is now on by default. This lets TSan detect
racing mutating methods even when those methods are not themselves instrumented
(such as methods on Standard Library collections).
This behavior can be disabled by passing:
-Xfrontend -disable-tsan-inout-instrumentation
when compiling under TSan.
rdar://problem/31069963
This PR addresses TODOs from #8241.
- It supports merging for layout constraints, e.g., if both a _Trivial constraint and a _Trivial(64) constraint appear on a type parameter, we keep only _Trivial(64) as a more specific layout constraint. We do a similar thing for ref-counted/native-ref-counted. The overall idea is to keep the more specific of two compatible layout constraints.
- The presence of a superclass constraint implies a layout constraint, e.g., a superclass constraint implies _Class or _NativeClass
- Add support for _Class and _NativeClass layout constraints, which are supposed to represent T: Superclass and P: class constraints in the future.
- Use the re-factoring to also reduce the number of dynamic allocations when creating layout constraints. Simple non-parametrized layout constraints are now represented as statically allocated singletons (static members of LayoutConstraintInfo).
* Refactor Tuple Type Syntax
This patch:
- Refactors TypeArgumentListSyntax and
TypeArgumentListSyntaxData to use the SyntaxCollection and
SyntaxCollectionData APIs.
- Refactors TupleTypeElementSyntax to own its trailing comma, and
updates the tests accordingly.
- Provides an infrastructure for promoting types to use
the SyntaxCollection APIs
* Addressed comments.
* Renamed makeBlankTypeArgumentList()
* Update makeTupleType
* Changed makeTupleType to take an element list.
* Updated comment.
* Improved API for creating TupleTypeElementListSyntax'es
* Added round-trip test
* Removed last TypeArgumentList holdovers.
* Fixed round-trip test invocation
Diagnose redundant same-type constraints using most of the same
machinery for diagnosing other redundant constraints. However,
same-type constraints are particularly interesting because
redundancies can be spelled in a number of different ways. Address
this using the connected components of the subgraph involving only
derived requirements (which is already used for the minimized generic
signature). Then, separate all of the non-derived requirements into
the intracomponent requirements and intercomponent requirements:
* All of the intracomponent requirements are redundant by definition,
because the components are defined by derived constraints.
* For the intercomponent requirements, form a spanning tree among the
various components and diagnose as redundant any edges that do not
extend the spanning tree.
It's better to compute this information once while we're sorting
through all of the same-type constraints, so we can use it later when
performing queries (e.g., enumerating requirements).
foo(_: 3) is equivalent to foo(3), so calling a function that has _ as
an argument label (func foo(`_`: 3)) still requires the _ to be
escaped. Before this patch, the compiler would suggest removing the `s,
even though that changes behaviour.
Fixes rdar://problem/31077797.
Use -sil-partial-specialization-with-generic-substitutions to enable the partial specialization even in cases of substitutions containing generic replacement types.
