Add `llvm_unreachable` to mark covered switches which MSVC does not
analyze correctly and believes that there exists a path through the
function without a return value.
Instead of a thunk insert the dispatch into the original function.
If the original function should be executed the prolog just jumps to the "real" code in the function. Otherwise the replacement function is called.
There is one little complication here: when the replacement function calls the original function, the original function should not dispatch to the replacement again.
To pass this information, we use a flag in thread local storage.
The setting and reading of the flag is done in two new runtime functions.
rdar://problem/51043781
These can be recreated if needed in a client library. To do this, I've
added a new ConformanceLookupKind::NonInherited, which can also be
used elsewhere in the project where we're already filtering out
inherited conformances some other way.
Note that this doesn't drop inherited conformances from the entire
serialized interface, just from the list that a class explicitly
declares. They still get referenced sometimes.
rdar://problem/50541451 and possibly others
This logic is no longer guarded by a flag. Sema will still emit certain
diagnostics if the flag is not specified though.
Progress on <rdar://problem/49090631>.
This is to support dynamic function replacement of functions with opaque
result type.
This approach requires that all state is thrown away (that could contain the
old returned type for an opaque type) between replacements.
rdar://48887938
To represent the abstracted interface of an opaque type, we need a generic signature that refines
the outer context generic signature with an additional generic parameter representing the underlying
type and its exposed constraints. Opaque types also need to be keyed by their originating decl, so
that we can treat values of the same opaque type as the same. When we check a FuncDecl with an
opaque type specified as its return type, create an OpaqueTypeDecl and associate it with the
originating decl. (A representation for *types* derived from the opaque decl will come next.)
In LLDB expressions, references to private metadata accessors may be
emitted and need to be bound to symbols available in the attached
program, even if these symbols are only supposed to have private
visibility within the program.
Also rdar://problem/48018240
Non-generic classes with resilient ancestry do not have statically-emitted
metadata, so we can now emit an Objective-C resilient class stub instead.
Also, when emitting an Objective-C category, reference the class stub if
the class has resilient ancestry; previously this case would hit an assert.
Note that class stubs always start with a zero word, with the address point
pointing immediately after. This works around a linker issue, where the
linker tries to coalesce categories and gets confused upon encountering a
class stub.
To correctly call designated super class initializers the designated
intializer (and not the allocator) is dynamically replaceable.
Convenience allocators are dynamically replaceable as before.
Start emitting associated conformance requirement descriptors for
inherited protocols, so we have a symbol to reference from resilient
witness tables and mangled names in the future.
A dynamically replaceable function calls through a global variable that
holds the function pointer.
struct ChainEntry {
void *(funPtr)();
struct ChainEntry *next;
}
ChainEntry dynamicallyReplaceableVar;
void dynamicallyReplaceableFunction() {
dynamicallyReplaceableVar.funPtr()
}
dynamic replacements will be chainable so the global variable also
functions as the root entry in the chain of replacements.
A dynamic replacement functions can call the previous implementation by
going through its chain entry.
ChainEntry chainEntryOf_dynamic_replacement_for_foo;
void dynamic_replacement_for_foo() {
// call the previous (original) implementation.
chainEntryOf_dynamic_replacement_for_foo.funPtr();
}
Witness table accessors return a witness table for a given type's
conformance to a protocol. They are called directly from IRGen
(when we need the witness table instance) and from runtime conformance
checking (swift_conformsToProtocol digs the access function out of the
protocol conformance record). They have two interesting functions:
1) For witness tables requiring instantiation, they call
swift_instantiateWitnessTable directly.
2) For synthesized witness tables that might not be unique, they call
swift_getForeignWitnessTable.
Extend swift_instantiateWitnessTable() to handle both runtime
uniquing (for #2) as well as handling witness tables that don't have
a "generic table", i.e., don't need any actual instantiation. Use it
as the universal entry point for "get a witness table given a specific
conformance descriptor and type", eliminating witness table accessors
entirely.
Make a few related simplifications:
* Drop the "pattern" from the generic witness table. Instead, store
the pattern in the main part of the conformance descriptor, always.
* Drop the "conformance kind" from the protocol conformance
descriptor, since it was only there to distinguish between witness
table (pattern) vs. witness table accessor.
* Internalize swift_getForeignWitnessTable(); IRGen no longer needs to
call it.
Reduces the code size of the standard library (+assertions build) by
~149k.
Addresses rdar://problem/45489388.
The former appears in the code base a lot more frequently than the
latter, which returns a GenericTypeParamType *. Use it only in places
where the more specific type is intended.
Replace the quadratic algorithm (currently O(m*n) where m is the number of requirements and n is the number of witnesses) with an O(m+n) algorithm.
Harden the algorithm a against bad and unexpected inputs:
* Fail if the requirement descriptor is out-of-bounds for the protocol
* Skip the witness if the requirement descriptor is null; this can happen
when the witness table was compiled against a newer version of the
protocol, but is deployed to a library containing an older version of the
protocol. It is expected.
* In debug builds of the runtime, complain if an entry is initialized twice
* In debug builds of the runtime, complain if an entry is NULL
Fixes rdar://problem/44434793, which covers the second bullet (backward
deployment).
For a resilient conformance, emit the associated conformance accessor
functions into the resilient witness table (keyed on the associated
conformance descriptor) rather than in the fixed part of the witness
table. This is another part of resilience for associated conformances,
and a step toward defaults for associated conformances.
Associated conformance descriptors are aliases that refer to associated
conformance requirements within a protocol descriptor’s list of
requirements. They will be used to provide protocol resilience against
the addition of new associated conformance requirements (which only makes
sense for newly-introduced, defaulted associated types).
Generic parameter references, which occur in generic requirement
metadata, were hardcoding associated type indices. Instead, use
relative references to associated type descriptors and perform the
index calculation at runtime.
Associated types can now be reordered resiliently (without relying on
sorting), which is the first main step toward rdar://problem/44167982.
Introduce an alias that refers one element prior to the start of a
protocol descriptor’s protocol requirements. This can be subtracted from
an associated type descriptor address to determine the offset of the
associated type accessor within a corresponding witness table. The code
generation for the latter is not yet implemented.
Previously, TBDGen skipped emitting lazy initializers for globals that
appeared in any file with an entry point. This breaks, however on files
that have an NSApplicationMain/UIApplicationMain class in them, where
the entry point is synthesized but top-level globals are not locally
scoped. This change re-uses SILGen's check and only skips variable
declarations that appear at top level in a script mode file.
Resolves rdar://43549749
- getAsDeclOrDeclExtensionContext -> getAsDecl
This is basically the same as a dyn_cast, so it should use a 'getAs'
name like TypeBase does.
- getAsNominalTypeOrNominalTypeExtensionContext -> getSelfNominalTypeDecl
- getAsClassOrClassExtensionContext -> getSelfClassDecl
- getAsEnumOrEnumExtensionContext -> getSelfEnumDecl
- getAsStructOrStructExtensionContext -> getSelfStructDecl
- getAsProtocolOrProtocolExtensionContext -> getSelfProtocolDecl
- getAsTypeOrTypeExtensionContext -> getSelfTypeDecl (private)
These do /not/ return some form of 'this'; instead, they get the
extended types when 'this' is an extension. They started off life with
'is' names, which makes sense, but changed to this at some point. The
names I went with match up with getSelfInterfaceType and
getSelfTypeInContext, even though strictly speaking they're closer to
what getDeclaredInterfaceType does. But it didn't seem right to claim
that an extension "declares" the ClassDecl here.
- getAsProtocolExtensionContext -> getExtendedProtocolDecl
Like the above, this didn't return the ExtensionDecl; it returned its
extended type.
This entire commit is a mechanical change: find-and-replace, followed
by manual reformatted but no code changes.
* [TBDGen] Allow user-provided dylib version flags
This patch adds two frontend arguments, -tbd-compatibility-version and
-tbd-current-version, both of which accept SemVer versions.
These will show up in the generated TBD file for a given module as
current-version: 2.7
compatibility-version: 2.0
These flags both default to `1.0.0`.
* Reword some comments
* Add test for invalid version string
* Expand on comments for TBD flags
`@_silgen_name` functions with no body are forward-declarations of
existing symbols, only to appease the typechecker. They don't show up in
the IR, so don't add them to the TBD file.
