ASTWalker visits a lazy_initializer_expr once within its associated
var_decl (by way of the parent nominal type). However, SILGen visits the
lazy_initializer_expr while inside of the var_decl's getter. The result
is that there is no coverage mapping information for the contents of the
lazy init within the getter's SILProfiler.
Fixing this will require reworking how profile counters are assigned to
be more in line with what SILGen needs.
As a stop-gap, this patch prevents SILGen from asserting that coverage
mappings are complete with a defensive check which prevents a crash seen
in SR-8429.
rdar://42792053
Previously SILModule contained two different pathways for the deserializer to
send notifications that it had created functions:
1. A list of function pointers that were called when a function's body was
deserialized. This was added recently so that access enforcement elimination is
run on newly deserialized SIL code if we have already eliminated access
enforcement from the module.
2. SILModule::SerializationCallback. This is an implementation of the full
callback interface and is used by the SILModule to update linkage and other
sorts of book keeping.
To fix the pass manager notification infrastructure, I need to be able to send
notifications to a SILPassManager when deserializing. I also need to be able to
eliminate these callbacks when a SILPassManager is destroyed. These requirements
are incompatible with the current two implementations since: (2) is an
implementation detail of SILModule and (1) only notifies on function bodies
being deserialized instead of the creation of new declarations (what the caller
analysis wants).
Rather than adding a third group of callbacks, this commit refactors the
infrastructure in such a way that all of these use cases can use one
implementation. This is done by:
1. Lifting the interface of SerializedSILLoader::Callback into a base
notification protocol for deserialization called
DeserializationNotificationHandlerBase and its base no-op implementation into an
implementation of the aforementioned protocol:
DeserializationNotificationHandler.
2. Changing SILModule::SerializationCallback to implement
DeserializationNotificationHandler.
3. Creating a class called FunctionBodyDeserializationNotificationHandler that
takes in a function pointer and uses that to just override the
didDeserializeFunctionBody. This eliminates the need for the specific function
body deserialization list.
4. Replacing the state associated with the two other pathways with a single
DeserializationNotificationHandlerSet class that contains a set of
DeserializationNotificationHandler and chains notifications to them. This set
implements DeserializationNotificationHandlerBase so we know that its
implementation will always be in sync with DeserializationNotificationHandler.
rdar://42301529
ConvertFunction and reabstraction thunks need this attribute. Otherwise,
there is no way to identify that withoutActuallyEscaping was used
to explicitly perform a conversion.
The destination of a [without_actually_escaping] conversion always has
an escaping function type. The source may have either an escaping or
@noescape function type. The conversion itself may be a nop, and there
is nothing distinctive about it. The thing that is special about these
conversions is that the source function type may have unboxed
captures. i.e. they have @inout_aliasable parameters. Exclusivity
requires that the compiler enforce a SIL data flow invariant that
nonescaping closures with unboxed captures can never be stored or
passed as an @escaping function argument. Adding this attribute allows
the compiler to enforce the invariant in general with an escape hatch
for withoutActuallyEscaping.
That is, don't look through InOutType anymore, and update callers to
call getInOutObjectType() as well (or not, where it was obvious to me
that InOutType could not appear).
This surfaces more remaining uses of getInOutObjectType() directly.
1) It's possible to materialize a tuple value with an @escaping or
@autoclosure element in it.
I don't think this causes any bad behavior in 4.2 because these
flags have no semantic effect after the type checker, but now
I'm adding an assertion that will fire when such types are
serialized, so let's make sure it doesn't happen by explicitly
clearing out these flags when lowering tuples types.
2) It's also possible to materialize a tuple with a single vararg
element. Again, this was not a problem in 4.2, but with the above
change to start clearing tuple flags, we now end up in a
situation where the lowered type is not a tuple, because
TupleType::get() returns a ParenType if the tuple has one
element that is not vararg (which it no longer is, because we
just cleared all the flags).
Fix the second problem by treating one-element vararg tuples just
like tuples with inout, __shared and __owned elements, that is,
by always exploding them when they appear at the top level of a
function parameter list, ensuring we never try to materialize
a value whose type is the entire tuple type.
These problems all stem from the fact that lowering a function type
with the opaque abstraction pattern treats the top level argument
list as a single tuple argument. Once that is fixed, much of the
above will simplify down to assertions.
Even with an opaque abstraction pattern, we must explode a
parameter list containing __shared and __owned elements.
Otherwise, we produce invalid lowered SIL types.
Note that this is already an issue, because the stdlib has a
handful of declarations using __owned.
These are trivial functions and should be inlined away; the only
tricky bit is they need to be defined after the iterator type.
This gives a slight speedup of stdlib compilation time (about 5%
of the time spent generating the swiftmodule).
Introduce ExtensionDecl::getExtendedNominal() to provide the nominal
type declaration that the extension declaration extends. Move most
of the existing callers of the callers to getExtendedType() over to
getExtendedNominal(), because they don’t need the full type information.
ExtensionDecl::getExtendedNominal() is itself not very interesting yet,
because it depends on getExtendedType().
This patch adds SIL-level debug info support for variables whose
static type is rewritten by an optimizer transformation. When a
function is (generic-)specialized or inlined, the static types of
inlined variables my change as they are remapped into the generic
environment of the inlined call site. With this patch all inlined
SILDebugScopes that point to functions with a generic signature are
recursively rewritten to point to clones of the original function with
new unique mangled names. The new mangled names consist of the old
mangled names plus the new substituions, similar (or exactly,
respectively) to how generic specialization is handled.
On libSwiftCore.dylib (x86_64), this yields a 17% increase in unique
source vars and a ~24% increase in variables with a debug location.
rdar://problem/28859432
rdar://problem/34526036
Add an abstraction to retrieve a name suitable for display for a given
source location for use with diagnostics, debug locations, and magic
file literals.
This was undoing the effects of 36eae9d4f, which is supposed to
guarantee trapping behavior on unexpected values. Worse, it put
switches that *actually had defaults* back into
undefined-behavior-land if a case were added.
The verifier changes are in lieu of test changes; this was originally
caught by IRGen/CoreGraphics_test.swift.
rdar://problem/42775178
ClassDecl::getSuperclass() produces a complete interface type describing the
superclass of a class, including any generic arguments (for a generic type).
Most callers only need the referenced ClassDecl, which is (now) cheaper
to compute: switch those callers over to ClassDecl::getSuperclassDecl().
Fixes an existing test for SR-5993.
Switch a number of callers of the Type-based lookupQualified() over to
the newer (and preferred) declaration-based lookupQualified(). These are
the easy ones; NFC.
This commit does not modify those APIs or their usage. It just:
1. Moves the APIs onto SILFunctionBuilder and makes SILFunctionBuilder a friend
of SILModule.
2. Hides the APIs on SILModule so all users need to use SILFunctionBuilder to
create/destroy functions.
I am doing this in order to allow for adding/removing function notifications to
be enforced via the type system in the SILOptimizer. In the process of finishing
off CallerAnalysis for FSO, I discovered that we were not doing this everywhere
we need to. After considering various other options such as:
1. Verifying after all passes that the notifications were sent correctly and
asserting. Turned out to be expensive.
2. Putting a callback in SILModule. This would add an unnecessary virtual call.
I realized that by using a builder we can:
1. Enforce that users of SILFunctionBuilder can only construct composed function
builders by making the composed function builder's friends of
SILFunctionBuilder (notice I did not use the word subclass, I am talking
about a pure composition).
2. Refactor a huge amount of code in SILOpt/SILGen that involve function
creation onto a SILGenFunctionBuilder/SILOptFunctionBuilder struct. Many of
the SILFunction creation code in question are straight up copies of each
other with small variations. A builder would be a great way to simplify that
code.
3. Reduce the size of SILModule.cpp by 25% from ~30k -> ~23k making the whole
file easier to read.
NOTE: In this commit, I do not hide the constructor of SILFunctionBuilder since
I have not created the derived builder structs yet. Once I have created those in
a subsequent commit, I will hide that constructor.
rdar://42301529
Add support to static diagnostics for tracking noescape closures through block
arguments.
Improve the noescape closure SIL verification logic to match. Cleanup noescape
closure handling in both diagnostics and SIL verification to be more
robust--they must perfectly match each other.
Fixes <rdar://problem/42560459> [Exclusivity] Failure to statically diagnose a
conflict when passing conditional noescape closures.
Initially reported in [SR-8266] Compiler crash when checking exclusivity of
inout alias.
Example:
struct S {
var x: Int
mutating func takeNoescapeClosure(_ f: ()->()) { f() }
mutating func testNoescapePartialApplyPhiUse(z : Bool) {
func f1() {
x = 1 // expected-note {{conflicting access is here}}
}
func f2() {
x = 1 // expected-note {{conflicting access is here}}
}
takeNoescapeClosure(z ? f1 : f2)
// expected-error@-1 2 {{overlapping accesses to 'self', but modification requires exclusive access; consider copying to a local variable}}
}
}
Allows a SIL pass to follow a def-use chain through phis.
Other terminators can also propagate values through block arguments, but they
always need special handling.
