This bug was caught by the SIL verifier. Any invocation of a NoReturn function should be followed by an `unreachable` instruction.
Fixes rdar://problem/33591235
Till now createApply, createTryApply, createPartialApply were taking some arguments like SubstCalleeType or ResultType. But these arguments are redundant and can be easily derived from other arguments of these functions. There is no need to put the burden of their computation on the clients of these APIs.
The removal of these redundant parameters simplifies the APIs and reduces the possibility of providing mismatched types by clients, which often happened in the past.
At some point, pass definitions were heavily macro-ized. Pass
descriptive names were added in two places. This is not only redundant
but a source of confusion. You could waste a lot of time grepping for
the wrong string. I removed all the getName() overrides which, at
around 90 passes, was a fairly significant amount of code bloat.
Any pass that we want to be able to invoke by name from a tool
(sil-opt) or pipeline plan *should* have unique type name, enum value,
commend-line string, and name string. I removed a comment about the
various inliner passes that contradicted that.
Side note: We should be consistent with the policy that a pass is
identified by its type. We have a couple passes, LICM and CSE, which
currently violate that convention.
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
This would create control-flow that the unsafeGuaranteed optimization cannot
handle.
unmanaged._withUnsafeGuaranteedRef {
$0.methodCall()
}
rdar://30949999
Most of this involved sprinkling ValueOwnershipKind::Owned in many places. In
some of these places, I am sure I was too cavalier and I expect some of them to
be trivial. The verifier will help me to track those down.
On the other hand, I do expect there to be some places where we are willing to
accept guaranteed+trivial or owned+trivial. In those cases, I am going to
provide an aggregate ValueOwnershipKind that will then tell SILArgument that it
should disambiguate using the type. This will eliminate the ackwardness from
such code.
I am going to use a verifier to fix such cases.
This commit also begins the serialization of ValueOwnershipKind of arguments,
but does not implement parsing of value ownership kinds. That and undef are the
last places that we still use ValueOwnershipKind::Any.
rdar://29791263
We preserve the current behavior of assuming Any ownership always and use
default arguments to hide this change most of the time. There are asserts now in
the SILBasicBlock::{create,replace,insert}{PHI,Function}Argument to ensure that
the people can only create SILFunctionArguments in entry blocks and
SILPHIArguments in non-entry blocks. This will ensure that the code in tree
maintains the API distinction even if we are not using the full distinction in
between the two.
Once the verifier is finished being upstreamed, I am going to audit the
createPHIArgument cases for the proper ownership. This is b/c I will be able to
use the verifier to properly debug the code. At that point, I will also start
serializing/printing/parsing the ownershipkind of SILPHIArguments, but lets take
things one step at a time and move incrementally.
In the process, I also discovered a CSE bug. I am not sure how it ever worked.
Basically we replace an argument with a new argument type but return the uses of
the old argument to refer to the old argument instead of a new argument.
rdar://29671437
Changes:
* Terminate all namespaces with the correct closing comment.
* Make sure argument names in comments match the corresponding parameter name.
* Remove redundant get() calls on smart pointers.
* Prefer using "override" or "final" instead of "virtual". Remove "virtual" where appropriate.
Before this commit all code relating to handling arguments in SILBasicBlock had
somewhere in the name BB. This is redundant given that the class's name is
already SILBasicBlock. This commit drops those names.
Some examples:
getBBArg() => getArgument()
BBArgList => ArgumentList
bbarg_begin() => args_begin()
The behaviour of ilist has changed in LLVM. It is no longer permissible to
dereference the `end()` value. Add a check to ensure that we do not
accidentally dereference the iterator.
When devirtualizing witness method and class method calls, we
transform apply instructions operating on the result of a SIL
witness_method or class_method instruction to direct calls of
a function_ref.
The generic signature of the dynamic call site might not match
the generic signature of the static thunk, so the substitution
list from the dynamic apply instruction cannot be used directly;
instead, we must transform it to a substitution list suitable
for the static thunk.
- With witness methods, the method is called using the protocol
requirement's signature, <Self : P, ...>, however the
witness thunk has a generic signature derived from the
concrete witness.
For example, the requirement might have a signature
<Self : P, T>, where the concrete witness thunk might
have a signature <X, Y>, where the concrete conforming type
is G<X, Y>.
At the call site, we substitute Self := G<X', Y'>; however
to be able to call the witness thunk directly, we need to
form substitutions X := X' and Y := Y'.
- A similar situation occurs with class methods when the
dynamically-dispatched call is performed against a derived
class, but devirtualization actually finds the method on a
base class of the derived class.
The base class may have a different number of generic
parameters than the derived class, either because the
derived class makes some generic parameters of the base
class concrete, or if the derived class introduces new
generic parameters of its own.
In both cases, we need to consider the generic signature of the
dynamic call site (the protocol requirement or the derived
class method) as well as the generic signature of the static
thunk, and carefully remap the substitutions from one form
into another.
Previously the optimizer would implicitly rely on substitutions
being in AllArchetypes order, in particular that concatenating
outer substitutions with inner substitutions makes sense.
This assumption is about to go away, so this patch refactors
the optimizer to use some new abstractions for remapping
substitution lists.
If a SILBuilder creates a new instruction based on an old instruction and a new instruction is supposed to use some opened archetypes, one needs to set a proper opened archetypes context in the builder based on the opened archetypes used by the old instruction.
This fixes rdar://28024272
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.
'fileprivate' is considered a broader level of access than 'private',
but for now both of them are still available to the entire file. This
is intended as a migration aid.
One interesting fallout of the "access scope" model described in
758cf64 is that something declared 'private' at file scope is actually
treated as 'fileprivate' for diagnostic purposes. This is something
we can fix later, once the full model is in place. (It's not really
/wrong/ in that they have identical behavior, but diagnostics still
shouldn't refer to a type explicitly declared 'private' as
'fileprivate'.)
As a note, ValueDecl::getEffectiveAccess will always return 'FilePrivate'
rather than 'Private'; for purposes of optimization and code generation,
we should never try to distinguish these two cases.
This should have essentially no effect on code that's /not/ using
'fileprivate' other than altered diagnostics.
Progress on SE-0025 ('fileprivate' and 'private')
- Don't crash if a class_method instruction could not be devirtualized.
- Improve devirtualization of methods with generic parameters and using dependent types.
- Fix a bug in isBindableToSuperclassOf, uncovered while fixing the original bug reported in SR-1206.
This bug could lead in certain cases to invocations of a wrong method from the base class, instead
of using a method from a derived class.
rdar://25891588 and SR-1206
In many places, we're interested in whether a type with archetypes *might be* a superclass of another type with the right bindings, particularly in the optimizer. Provide a separate Type::isBindableToSuperclassOf method that performs this check. Use it in the devirtualizer to fix rdar://problem/24993618. Using it might unblock other places where the optimizer is conservative, but we can fix those separately.
If a class has an @objc ancestry this class can be dynamically overridden and
therefore we don't know the default case even if we see the full class
hierarchy.
rdar://23228386
SILValue.h/.cpp just defines the SIL base classes. Referring to specific instructions is a (small) kind of layering violation.
Also I want to keep SILValue small so that it is really just a type alias of ValueBase*.
NFC.
Correct format:
```
//===--- Name of file - Description ----------------------------*- Lang -*-===//
```
Notes:
* Comment line should be exactly 80 chars.
* Padding: Pad with dashes after "Description" to reach 80 chars.
* "Name of file", "Description" and "Lang" are all optional.
* In case of missing "Lang": drop the "-*-" markers.
* In case of missing space: drop one, two or three dashes before "Name of file".
(libraries now)
It has been generally agreed that we need to do this reorg, and now
seems like the perfect time. Some major pass reorganization is in the
works.
This does not have to be the final word on the matter. The consensus
among those working on the code is that it's much better than what we
had and a better starting point for future bike shedding.
Note that the previous organization was designed to allow separate
analysis and optimization libraries. It turns out this is an
artificial distinction and not an important goal.
