SILType substitutions are still done with the old form, and until
BoundGenericTypes hold conformances, we still have to pass around
a ModuleDecl in a few places we really shouldn't, but one step
at a time.
ExprHandle is a relic from a horrible time when expressions made their
way into the type system via default arguments. It's been unnecessary
for a long time, so get rid of it.
This patch is rather large, since it was hard to make this change
incrementally, but most of the changes are mechanical.
Now that we have a lighter-weight data structure in the AST for mapping
interface types to archetypes and vice versa, use that in SIL instead of
a GenericParamList.
This means that when serializing a SILFunction body, we no longer need to
serialize references to archetypes from other modules.
Several methods used for forming substitutions can now be moved from
GenericParamList to GenericEnvironment.
Also, GenericParamList::cloneWithOuterParameters() and
GenericParamList::getEmpty() can now go away, since they were only used
when SILGen-ing witness thunks.
Finally, when printing generic parameters with identical names, the
SIL printer used to number them from highest depth to lowest, by
walking generic parameter lists starting with the innermost one.
Now, ambiguous generic parameters are numbered from lowest depth
to highest, by walking the generic signature, which means test
output in one of the SILGen tests has changed.
When we call the DeclContext variants of these, use the
DeclContext's GenericEnvironment instead of GenericParamList.
Also, these functions would take a resolver argument, but we
always passed in nullptr, so just remove it now.
The old GenericParamList-based versions are still there
since they're called directly from SIL. They will go away
once SILFunction::ContextGenericParams is replaced with
a GenericEnvironment.
This is the first, and most trivial, usage of the new
GenericSignature::getSubstitutions() method.
Note that getForwardingSubstitutions() now takes a
GenericSignature, which is slightly awkward.
However, this is in line with our goal of 'hollowing out'
GenericParamList by removing knowledge of the finalized
generic requirements.
Also, there is now a new getForwardingSubstitutionMap()
function, which returns an interface type substitution
mapping. This is used in the new getForwardingSubstitutions()
implementation, and all also be used elsewhere later.
Finally, in the SILFunction we now cache the forwarding
substitutions, instead of re-computing them every time.
I doubt this makes a big difference in performance, but
it's a simple enhancement and every little bit helps.
This eliminates a pile of now-dead code in:
* The type checker, where we no longer have special cases for bridging conversions
* The expression ASTs, where we no longer need to distinguish bridging collection up/down casts
* SILGen, which no longer uses
Still to come is the removal of the
_(set|dictionary)Bridge(From|To)ObjectiveC(Conditional)? entrypoints
from the standard library. They're still used by some tests.
Simplify e.g., ASTContext::getBridgedToObjC(), which no longer needs
the optional return.
Eliminate the now-unused constraint kind for checking bridging to
Objective-C.
Bitcast the AnyObject result to AnyObject?, then call our new helper function, so that we can handle nils without choking. Fixes rdar://problem/27874026.
If an ObjC API claims to return a nonnull object of a bridged type, such as blocks, then we're already screwed since we don't take that possibility into account when bridging to a Swift function. Attempting to peephole that case only generates broken code attempting to bitcast () -> () to Optional<() -> ()>, which is invalid due to the abstraction change between () -> () and Optional<T>. Fixes SR-2331.
This is still a pretty bad code-generation pattern, but the layering
stuff makes it challenging to do the right thing.
Also, bridge non-optional NSErrors to Error using init_existential_ref
instead of going through the runtime function.
rdar://27810321
Naively wrapping a T in an Any would require metadata for T, but we can go to AnyObject first and put the AnyObject in the Any without T's metadata. This fixes a regression in ObjC generic extension methods when they try to pass their generic parameters to id parameters as Any. rdar://problem/27526877
SIL already does this where necessary, except with foreign throwing
functions; this patch changes Sema and the ClangImporter to give
them an ObjCBool foreign error result type explicitly.
This fixes a problem where calls to functions taking and returning
the C99 _Bool type were miscompiled on Mac OS X x86-64, because
IRGen was conflating the Objective-C BOOL type (which is a signed
char on some platforms) and C99 _Bool (which lowers as the LLVM
i1 type).
Fixes <rdar://problem/26506458> and <rdar://problem/27365520>.
When emitting an existential erasure to Error from an archetype, use
the _getEmbeddedNSError() witness. If it produces an NSError, erase
that; otherwise, go through the normal erasure path.
Of course, make NSError and CFError implement _getEmbeddedNSError() so
this kicks in for the obvious cases as well as the more obscure ones.
Fixes the rest of SR-1562 / rdar://problem/26370984.
Imported Cocoa error types are represented by structs wrapping an
NSError. The conversion from these structs to Error would end up
boxing the structs in _SwiftNativeNSError, losing identity and leading
to a wrapping loop.
Instead, extract the embedded NSError if there is one. In the Swift
runtime, do this as part of the dynamic cast to NSError, using a (new,
defaulted) requirement in the Error type so we can avoid an extra
runtime lookup of the protocol. In SILGEn, do this by looking for the
_BridgedStoredNSError protocol conformance when erasing to an Error
type. Fixes SR-1562 / rdar://problem/26370984.
Previously, if a generic type had a stored property with
a generic type and an initializer expression, we would
emit the expression directly in the body of each designated
initializer.
This is a problem if the designated initializer is defined
within an extension (even in the same source file), because
extensions have a different set of generic parameters and
archetypes.
Also, we've had bugs in the past where emitting an
expression multiple times didn't work properly. While these
might currently all be fixed, this is a tricky case to test
and it would be best to avoid it.
Fix both problems by emitting the initializer expression
inside its own function at the SIL level, and call the
initializer function from each designated initializer.
I'm using the existing 'variable initializer' mangling for this;
it doesn't seem to be used for anything else right now.
Currently, the default memberwise initializer does not use
this, because the machinery for emitting it is somewhat
duplicated and separate from the initializer expressions in
user-defined constructors. I'll clean this up in an upcoming
patch.
Fixes <https://bugs.swift.org/browse/SR-488>.
One minor revision: this lifts the proposed restriction against
overriding a non-open method with an open one. On reflection,
that was inconsistent with the existing rule permitting non-public
methods to be overridden with public ones. The restriction on
subclassing a non-open class with an open class remains, and is
in fact consistent with the existing access rule.
Synthesizing a VarDecl for #dsohandle causes some unwanted accessors to
be expected, but we really don't need them: this is a global variable
for the start of the image. There are only two uses of getDSOHandle:
getting the type and emitting the SIL for it. Rather than perform
acrobatics to turn off switches, just emit access directly where it's
needed.
rdar://problem/26565092
String literal expressions, as well as the magic literals #file and
tuple value that is then fed into one or two call expressions. For
string literals, that tuple value was implicitly splatted, breaking
AST invariants.
Instead, keep string literals and these magic literals that produce a
string as a single expression node, but store the declarations that
will be used to transform the raw literal into the complete
literal. SILGen will form the appropriate calls. This representation
is far simpler---the AST no longer has a bunch of implicit nodes---and
doesn't break AST invariants.
What I've implemented here deviates from the current proposal text
in the following ways:
- I had to introduce a FunctionArrowPrecedence to capture the parsing
of -> in expression contexts.
- I found it convenient to continue to model the assignment property
explicitly.
- The comparison and casting operators have historically been
non-associative; I have chosen to preserve that, since I don't
think this proposal intended to change it.
- This uses the precedence group names and higherThan/lowerThan
as agreed in discussion.
* [Type System] Handle raw pointer conversion.
As proposed in SE-0107: UnsafeRawPointer.
https://github.com/apple/swift-evolution/blob/master/proposals/0107-unsaferawpointer.md#implicit-argument-conversion
UnsafeMutablePointer<T> -> UnsafeMutableRawPointer
UnsafeMutablePointer<T> -> UnsafeRawPointer
UnsafePointer<T> -> UnsafeRawPointer
UnsafeMutableRawPointer -> UnsafeRawPointer
inout:
&anyVar -> UnsafeMutableRawPointer
&anyVar -> UnsafeRawPointer
array -> UnsafeRawPointer
string -> UnsafeRawPointer
varArray -> UnsafeMutableRawPointer
* Rename expectEqual(_, _, sameValue:) to expectEqualTest to workaround a type system bug.
<rdar://26058520> Generic type constraints incorrectly applied to functions with the same name
This is exposed by additions to the type system for UnsafeRawPointer.
Warning: unit tests fail very confusingly without this fix.
The known __dso_handle symbol name wasn't getting used when emitting
references to #dsohandle, causing link time failures for a mangled
name that didn't exist.
rdar://problem/26565092
