When we saw a 'let' property of a class, then `emitRValueForStorageLoad` would give back the loaded borrowed property as-is without checking for reabstraction first. Fall back to copying and reabstracting in this case. Fixes rdar://problem/41056468.
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
I made this change by removing the SILOption and then doing a compile, fix loop. I
purposely did not move around the code to make the refactoring really easy to
see.
For now, the accessors have been underscored as `_read` and `_modify`.
I'll prepare an evolution proposal for this feature which should allow
us to remove the underscores or, y'know, rename them to `purple` and
`lettuce`.
`_read` accessors do not make any effort yet to avoid copying the
value being yielded. I'll work on it in follow-up patches.
Opaque accesses to properties and subscripts defined with `_modify`
accessors will use an inefficient `materializeForSet` pattern that
materializes the value to a temporary instead of accessing it in-place.
That will be fixed by migrating to `modify` over `materializeForSet`,
which is next up after the `read` optimizations.
SIL ownership verification doesn't pass yet for the test cases here
because of a general fault in SILGen where borrows can outlive their
borrowed value due to being cleaned up on the general cleanup stack
when the borrowed value is cleaned up on the formal-access stack.
Michael, Andy, and I discussed various ways to fix this, but it seems
clear to me that it's not in any way specific to coroutine accesses.
rdar://35399664
Now, an AbstractFunctionDecl always stores a single parameter list.
Furthermore, ConstructorDecl and DestructorDecl always store a
ParamDecl for 'self'.
FuncDecl only has a 'self' if it is a member of a nominal type or
extension, so we tail-allocate the storage for it.
There were several bits of code which were unnecessarily
repeating the core logic of breaking down an access strategy
and either setting up an LValue or directly emitting it.
These places have now been unified to just create and then
load or othrwise use an LValue.
Introduce a visitor which handles the common parts of breaking
down an access strategy and computing information like the
LValueTypeData. In addition to its direct benefits (which are
somewhat lost in the boilerplate of capturing local state into
the visitor subclass), this eliminates some of the ad-hocness
of how the various emission paths use AccessStrategy.
Finally, implement the MaterializeToTemporary strategy in its
full generality by using the actual read and write sub-strategies
instead of always falling back on calling the getter and setter.
This part is not NFC because it causes us to perform the read
part of a read/write to a stored-with-observers property by
directly accessing the storage instead of calling the getter.
Modifies SILGen and the `Swift._diagnoseUnexpectedNilOptional` call to print a slightly different message for force unwraps which were implicitly inserted by the compiler for IUOs. The message is chosen based on the presence of certain flags in the `ForceValueExpr`, not on the type of the value being unwrapped.
The other side of #17404. Since we don't want to generate up front key path metadata for properties/subscripts with no withheld implementation details, the client should generate a key path component that can be used to represent a key path component based on its public interface.
The storage kind has been replaced with three separate "impl kinds",
one for each of the basic access kinds (read, write, and read/write).
This makes it far easier to mix-and-match implementations of different
accessors, as well as subtleties like implementing both a setter
and an independent read/write operation.
AccessStrategy has become a bit more explicit about how exactly the
access should be implemented. For example, the accessor-based kinds
now carry the exact accessor intended to be used. Also, I've shifted
responsibilities slightly between AccessStrategy and AccessSemantics
so that AccessSemantics::Ordinary can be used except in the sorts of
semantic-bypasses that accessor synthesis wants. This requires
knowing the correct DC of the access when computing the access strategy;
the upshot is that SILGenFunction now needs a DC.
Accessor synthesis has been reworked so that only the declarations are
built immediately; body synthesis can be safely delayed out of the main
decl-checking path. This caused a large number of ramifications,
especially for lazy properties, and greatly inflated the size of this
patch. That is... really regrettable. The impetus for changing this
was necessity: I needed to rework accessor synthesis to end its reliance
on distinctions like Stored vs. StoredWithTrivialAccessors, and those
fixes were exposing serious re-entrancy problems, and fixing that... well.
Breaking the fixes apart at this point would be a serious endeavor.
Client code can make a best effort at emitting a key path referencing a property with its publicly exposed API, which in the common case will match what the defining module would produce as the canonical key path component representation of the declaration. We can reduce the code size impact of these descriptors by not emitting them when there's no hidden or possibly-resiliently-changed-in-the-past information about a storage declaration, having the property descriptor symbol reference a sentinel value telling client key paths to use their definition of the key path component.
This causes default arguments to get emitted after formal evaluation of `self`, allowing protocol methods to access the opened `Self` type of an existential receiver. Fixes rdar://problem/39524104
This reverts commit 742e7fc583. This
causes other source compatibility regressions due to the extended exclusive access to
the existential (such as rdar://problem/39524104). A false-positive
exclusivity failure might lead to runtime errors, whereas the cases we
can't support previous to this patch can at least reliably be handled
statically.
Every SubstitutionMap::toList() invocation would ASTContext-allocate
arrays for all of the conformances, then return a SmallVector of the
underlying substitutions, which both wastes memory *and* puts the onus
on the caller to allocate a copy of that outer SmallVector into the
ASTContext if it's going to be stored anywhere.
Stop the madness by caching an ASTContext-allocated SubstitutionList
within the storage for the SubstitutionMap. This both reduces repeated
allocations and eliminates the potential for errors.
Replace two prominent uses of SubstitutionList, in ConcreteDeclRef and
Witness, with SubstitutionMap. Deal with the myriad places where we
now have substitution maps and need substitution lists (or vice versa)
caused by this change.
Overall, removes ~50 explicit uses of SubstitutionList (of ~400).
