During the review of SE-0413, typed throws, the notion of a `do throws`
syntax for `do..catch` blocks came up. Implement that syntax and
semantics, as a way to explicitly specify the type of error that is
thrown from the `do` body in `do..catch` statement.
Prior to this patch, a "guard let" was being lowered with an implicit debug
location, causing it to be dropped in later stages of the compiler, and making
it impossible to set a breakpoint in that line.
This was tracked down to a piece of code in `SILGenFunction::emitExprInto`,
which takes an optional Location parameter that was being ignored in one code
path.
This accidentally started happening when I adjusted getEffectiveAccess to return `Public` for `Package` declarations in #69709. As a result, the optimizer thought it had more opportunities to go after declarations that used to be opaque. Unfortunately, this resulted in a miscompile as the devirtualizer was able to look through now-serialized package (static) functions. In one specific instance, the optimizer created direct calls to hidden accessors instead of going through the dispatch thunk.
Function body macros allow one to introduce a function body for a
particular function, either providing a body for a function that
doesn't have one, or wholesale replacing the body of a function that
was written with a new one.
Previously, the initializer expressions of lazy vars would only be marked as
subsumed when the getter body for the var was synthesized. This didn't work
with `-experimental-lazy-typechecking` since accessor synthesis was not
guaranteed to happen. Consequently, SILGen would emit the initializer even
though it was already subsumed and then assert/crash since the init had also
not been checked and contextualized. Now lazy var inits are marked subsumed in
the request creating storage.
Resolves rdar://118421753
Values produced by address-only `enum` instructions have non-none
ownership. And because `enum` is representation-changing, they have
`owned` ownership.
This corresponds at the opaque values SIL stage to the fact that at the
address-lowered SIL stage the storage location has non-trivial
initialization which must be `destroy_addr`d, regardless of whether an
empty case was stored to it.
As a follow up to https://github.com/apple/swift/pull/69841, clarify the
possible states that initializer expression of a pattern can be in. The
possible states are not checked, checked, and "checked and contextualized"
(which is the new state that was introduced and requestified in the previous
PR). This refactoring encodes the states more explicitly and renames a few
compiler APIs to better align with the new naming. NFC.
The logic here previously worked by computing the
exit count by taking the parent count and
subtracting any control flow that jumped out of the
clauses. With `try` handling fixed, this no longer
works correctly, since a `try` shouldn't be
subtracted if the error is caught be one of the
catches, as that's not actually leaving the
statement. We could write the logic to determine
where a `try` is jumping to, but the logic here is
already pretty brittle, relying on being sprinkled
in various different places.
For now, let's take the more straightforward
approach and handle do-catches the same way we
handle switches, we initialize the exit counter to
0, and add on each exit count of each branch. This
lets us re-use the existing CaseStmt handling
logic. This doesn't necessarily produce the most
optimal counter expressions, but I want to replace
this all with a SILOptimizer pass anyway, which
will be able to much more easily compute optimal
counter expressions.
rdar://100470244
A TypeExpr and other kinds of non-lvalue bases that the borrowed-base
visitor doesn't care about can be handled by calling back into the
original SILGenLValue instance.
resolves rdar://117082469
An immutable noncopyable capture borrows the captured value in-place and can't do anything
to modify it, and the may_assign_but_not_consume checking behaves badly with some code patterns
generated for resilient types when `self` is captured during a deinit. This change allows for
more accurate checking and fixes rdar://118427997.
Allow initializer expressions to be emitted during SILGen when
`-experimental-lazy-typecheck` is specified by introducing a new request that
fully typechecks the init expressions of pattern binding declarations
on-demand.
There are still a few rough edges, like missing support for wrapped properties
and incomplete handling of subsumed initializers. Fixing these issues is not an
immediate priority because in the short term `-experimental-lazy-typecheck`
will always be accompanied by `-enable-library-evolution` and
`-experimental-skip-non-exportable-decls`. This means that only the
initializers of properties on `@frozen` types will need to be emitted and
property wrappers are not yet fully supported on properties belonging to
`@frozen` types.
Resolves rdar://117448868
When -experimental-skip-non-exportable-decls is specified, the SIL for the
initializers of stored properties is unneeded and should be skipped so long as
the property does not belong to a `@frozen` type.
When -experimental-skip-non-exportable-decls is specified, the SIL for the
initializers and unsafe mutable addressors of global variables is unneeded and
should be skipped.
Match what we do in `emitThrow`. Both of these should be unified and
generalized, relying on the AST to provide the necessary conversions
rather than having SILGen re-derive them.
This peephole optimization in SILGen requires us to use the thrown
error for the context of a closure type rather than the thrown error
for the closure AST node itself.
I also included changes to the rest of the SIL optimizer pipeline to ensure that
the part of the optimizer pipeline before we lower tuple_addr_constructor (which
is right after we run TransferNonSendable) work as before.
The reason why I am doing this is that this ensures that diagnostic passes can
tell the difference in between:
```
x = (a, b, c)
```
and
```
x.0 = a
x.1 = b
x.2 = c
```
This is important for things like TransferNonSendable where assigning over the
entire tuple element is treated differently from if one were to initialize it in
pieces using projections.
rdar://117880194
Introduce SILGen support for reabstractions thunks that change the
error, between indirect and direct errors as well as conversions
amongst error types (e.g., from concrete to `any Error`).
