Support for @noescape SILFunctionTypes.
These are the underlying SIL changes necessary to implement the new
closure capture ABI.
Note: This includes a change to function name mangling that
primarily affects reabstraction thunks.
The new ABI will allow stack allocation of non-escaping closures as a
simple optimization.
The new ABI, and the stack allocation optimization, also require
closure context to be @guaranteed. That will be implemented as the
next step.
Many SIL passes pattern match partial_apply sequences. These all
needed to be fixed to handle the convert_function that SILGen now
emits. The conversion is now needed whenever a function declaration,
which has an escaping type, is passed into a @NoEscape argument.
In addition to supporting new SIL patterns, some optimizations like
inlining and SIL combine are now stronger which could perturb some
benchmark results.
These underlying SIL changes should be merged now to avoid conflicting
with other work. Minor benchmark discrepancies can be investigated as part of
the stack-allocation work.
* Add a noescape attribute to SILFunctionType.
And set this attribute correctly when lowering formal function types to SILFunctionTypes based on @escaping.
This will allow stack allocation of closures, and unblock a related ABI change.
* Flip the polarity on @noescape on SILFunctionType and clarify that
we don't default it.
* Emit withoutActuallyEscaping using a convert_function instruction.
It might be better to use a specialized instruction here, but I'll leave that up to Andy.
Andy: And I'll leave that to Arnold who is implementing SIL support for guaranteed ownership of thick function types.
* Fix SILGen and SIL Parsing.
* Fix the LoadableByAddress pass.
* Fix ClosureSpecializer.
* Fix performance inliner constant propagation.
* Fix the PartialApplyCombiner.
* Adjust SILFunctionType for thunks.
* Add mangling for @noescape/@escaping.
* Fix test cases for @noescape attribute, mangling, convert_function, etc.
* Fix exclusivity test cases.
* Fix AccessEnforcement.
* Fix SILCombine of convert_function -> apply.
* Fix ObjC bridging thunks.
* Various MandatoryInlining fixes.
* Fix SILCombine optimizeApplyOfConvertFunction.
* Fix more test cases after merging (again).
* Fix ClosureSpecializer. Hande convert_function cloning.
Be conservative when combining convert_function. Most of our code doesn't know
how to deal with function type mismatches yet.
* Fix MandatoryInlining.
Be conservative with function conversion. The inliner does not yet know how to
cast arguments or convert between throwing forms.
* Fix PartialApplyCombiner.
Previously, two constructors with the same full name and argument
types would get identical manglings even if they were declared
'private' or 'fileprivate' in different files. This would lead to
symbol collisions in whole-module builds. Add a new mangling node for
private discriminators on base-name-less decls to make this unique.
This still doesn't fix the existing issue with private members, named
or not, conflicting when they're in the /same/ file, but since Swift 4
makes those members visible to one another (SE-0169) that's only an
issue in Swift 3 mode anyway, and as such probably won't get fixed at
all.
rdar://problem/27758199
This reverts commit 25985cb764. For now,
we're trying to avoid spurious non-structural changes to the mangling,
so that the /old/ mangling doesn't appear to change. That doesn't mean
no changes at all, but we can save this one for later.
- Allow them to use substitutions.
- Consistently use 'a' as a mangling operator.
- For generic typealiases, include the alias as context for any generic
parameters.
Typealiases don't show up in symbol names, which always refer to
canonical types, but they are mangled for debug info and for USRs
(unique identifiers used by SourceKit), so it's good to get this
right.
A protocol composition with an explicit 'AnyObject' member is
now mangled as <protocol list> 'Xl'. For subclass existentials,
I changed the mangling from <protocol list> <class> 'XE' to
<protocol list> <class> 'Xl'.
Not used for anything just yet.
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.
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.
Previously it was part of swiftBasic.
The demangler library does not depend on llvm (except some header-only utilities like StringRef). Putting it into its own library makes sure that no llvm stuff will be linked into clients which use the demangler library.
This change also contains other refactoring, like moving demangler code into different files. This makes it easier to remove the old demangler from the runtime library when we switch to the new symbol mangling.
Also in this commit: remove some unused API functions from the demangler Context.
fixes rdar://problem/30503344
