and eliminate dead code. This is meant to be a replacement for the utility:
recursivelyDeleteTriviallyDeadInstructions. The new utility performs more aggresive
dead-code elimination for ownership SIL.
This patch also migrates most non-force-delete uses of
recursivelyDeleteTriviallyDeadInstructions to the new utility.
and migrates one force-delete use of recursivelyDeleteTriviallyDeadInstructions
(in IRGenPrepare) to use the new utility.
maps in the handling of partial applies. In particular, when using
substMap.subst(otherSubstMap), ensure that otherSubstMap is not empty.
Also, store the partial-apply instruction in the symbolic closure,
which makes it easier to debug errors in the folding of partial applies.
of closure literals in the constant evaluator, store the
substitution map that was in the constant evaluator state when
the closure creation site (partial_apply or thin_to_thick_function)
that created the symbolic closure was evaluated.
A substitution map is a mapping from generic type parameters to types.
This map is updated and maintained by the constant evaluator as it
evaluates function calls. At a partial-application site, the substitution
map captures the mapping from the types of the captured arguments (which
could be generic types) to the types of the symbolic value they represent
(which has to be concrete types). The substitution map would be necessary
to fold the symbolic closure into SIL code that constructs the closure
it represents.
symbolic values, which are used to represent constant struct and tuple
instances. Associating those symbolic values with the types of the
aggregate they are representing will allow writing some sanity checks,
and will also make constant folding of the symbolic values easier and
more robust.
of OSLogMessage constant evaluable and remove @_transparent annotation
from the methods. Also, improve diagnostics in the OSLogOptimization
pass as now it rely on seeing the appendInterpolation/Literal calls.
ProtocolConformanceRef already has an invalid state. Drop all of the
uses of Optional<ProtocolConformanceRef> and just use
ProtocolConformanceRef::forInvalid() to represent it. Mechanically
translate all of the callers and callsites to use this new
representation.
https://forums.swift.org/t/improving-the-representation-of-polymorphic-interfaces-in-sil-with-substituted-function-types/29711
This prepares SIL to be able to more accurately preserve the calling convention of
polymorphic generic interfaces by letting the type system represent "substituted function types".
We add a couple of fields to SILFunctionType to support this:
- A substitution map, accessed by `getSubstitutions()`, which maps the generic signature
of the function to its concrete implementation. This will allow, for instance, a protocol
witness for a requirement of type `<Self: P> (Self, ...) -> ...` for a concrete conforming
type `Foo` to express its type as `<Self: P> (Self, ...) -> ... for <Foo>`, preserving the relation
to the protocol interface without relying on the pile of hacks that is the `witness_method`
protocol.
- A bool for whether the generic signature of the function is "implied" by the substitutions.
If true, the generic signature isn't really part of the calling convention of the function.
This will allow closure types to distinguish a closure being passed to a generic function, like
`<T, U> in (*T, *U) -> T for <Int, String>`, from the concrete type `(*Int, *String) -> Int`,
which will make it easier for us to differentiate the representation of those as types, for
instance by giving them different pointer authentication discriminators to harden arm64e
code.
This patch is currently NFC, it just introduces the new APIs and takes a first pass at updating
code to use them. Much more work will need to be done once we start exercising these new
fields.
This does bifurcate some existing APIs:
- SILFunctionType now has two accessors to get its generic signature.
`getSubstGenericSignature` gets the generic signature that is used to apply its
substitution map, if any. `getInvocationGenericSignature` gets the generic signature
used to invoke the function at apply sites. These differ if the generic signature is
implied.
- SILParameterInfo and SILResultInfo values carry the unsubstituted types of the parameters
and results of the function. They now have two APIs to get that type. `getInterfaceType`
returns the unsubstituted type of the generic interface, and
`getArgumentType`/`getReturnValueType` produce the substituted type that is used at
apply sites.
partial applies (i.e., closure creations).
A new SymbolicValue: SymbolicClosure represents a closure. It
tracks the SILFunction corresponding to the target of the closure
and the SIL and Symbolic Values of the captured arguments. The
representation does not impose that all captured values must have an
associated symbolic value. This allows the evaluator to track
creations of closures whose captured arguments or bodies are not
constant evaluable.
This commit does not add support for closure applications. It only
adds suppport for closure creations, which correspond to partial_apply
instructions in SIL.
mode and separate out the code for top-level evaluation from the normal
step-by-step evaluation. This ensures that step-by-step evaluation
does not accidentally rely on any logic meant for top-level evaluation.
This change should not affect the observable behavior of the evaluator.
evaluator to precisely evaluate Builtin.assert_configuration.
Unify UnknownReason::Trap and UnknownReason::AssertionFailure error
values in the constant evaluator, now that we have 'condfail_message'
SIL instruction, which provides an error message for the traps.
@_semantics("constant_evaluable") annotation to denote constant
evaluable functions.
Add a test suite that uses the sil-opt pass ConstantEvaluableSubsetChecker.cpp
to check the constant evaluability of function in the OSLog
overlay.
of Swift code snippets. Add a new test: constant_evaluable_subset_test.swift
that tests Swift code snippets that are expected to be constant evaluable and
those that are not.
1. builtin "int_expect", which makes the evaluator work on more
integer operations such as left/right shift (with traps) and
integer conversions.
2. builtin "_assertConfiguration", which enables the evaluator
to work with debug stdlib.
3. builtin "ptrtoint", which enables the evaluator to track
StaticString
4. _assertionFailure API, which enables the evaluator to report
stdlib assertion failures encountered during constant evaluation.
Also, enable attaching auxiliary data with the enum "UnknownReason"
and use it to improve diagnostics for UnknownSymbolicValues,
which represent failures during constant evaluation.
With the advent of dynamic_function_ref the actual callee of such a ref
my vary. Optimizations should not assume to know the content of a
function referenced by dynamic_function_ref. Introduce
getReferencedFunctionOrNull which will return null for such function
refs. And getInitialReferencedFunction to return the referenced
function.
Use as appropriate.
rdar://50959798
This is needed now that const expr handles string operations/etc. There aren't
tests for this now since I would need to stub out the stdlib. But these are
pretty simple changes overall, I do not expect any problems, and I plan on
enabling this relatively soon.
`String.+=` function to `String.append` function, and use a new
semantics attribute for String.+=.
Teach the constant evaluator about `String.Append` instead of `String.+=`.
unknown symbolic values by renaming some diagnostics and
creating new unknown reasons for each type of failure that
can happen during constant evaluation.
(also referred to as flow-sensitive mode) so that the evaluator
can be used by clients to constant evaluate instructions in a
SILFunction body one by one following the flow of control.
Adds memory objects and addresses to the constant interpreter, and
teaches the constant interpreter to interpret various instructions that
deal with memory and addresses.
* Remove apparently obsolete builtin functions.
- Remove s_to_u_checked_conversion and u_to_s_checked_conversion functions from builtin AST parsing, SIL/IR generation and from SIL optimisations.
* Remove apparently obsolete builtin functions - unit tests.
- Remove unit tests for SIL transformations relating to s_to_u_checked_conversion and u_to_s_checked_conversion builtin functions.
* Remove apparently obsolete builtin functions.
- Remove s_to_u_checked_conversion and u_to_s_checked_conversion functions from builtin AST parsing, SIL/IR generation and from SIL optimisations.
* Remove apparently obsolete builtin functions - unit tests.
- Remove unit tests for SIL transformations relating to s_to_u_checked_conversion and u_to_s_checked_conversion builtin functions.
