Non-escapable struct definitions often have inicidental integer fields that are
unrelated to lifetime. Without an explicit initializer, the compiler would infer
these fields to be borrowed by the implicit intializer.
struct CountedSpan: ~Escapable {
let span: Span<Int>
let i: Int
/* infer: @lifetime(copy span, borrow i) init(...) */
}
This was done because
- we always want to infer lifetimes of synthesized code if possible
- inferring a borrow dependence is always conservative
But this was the wrong decision because it inevitabely results in lifetime
diagnostic errors elsewhere in the code that can't be tracked down at the use
site:
let span = CountedSpan(span: span, i: 3) // ERROR: span depends on the lifetime of this value
Instead, force the author of the data type to specify whether the type actually
depends on trivial fields or not. Such as:
struct CountedSpan: ~Escapable {
let span: Span<Int>
let i: Int
@lifetime(copy span) init(...) { ... }
}
This fix enables stricter diagnostics, so we need it in 6.2.
Fixes rdar://152130977 ([nonescapable] confusing diagnostic message when a
synthesized initializer generates dependence on an Int parameter)
Correctly diagnose this as:
"invalid use of inout dependence on the same inout parameter
@_lifetime(a: &a)
func f_inout_useless(a: inout MutableRawSpan) {}
Correctly diagnose this as:
"lifetime-dependent parameter must be 'inout'":
@_lifetime(a: borrow a)
func f_inout_useless(a: borrowing MutableRawSpan) {}
This comes up often when passing a MutableSpan as an 'inout' argument. The
vague diagnostic was causing developers to attempt incorrect @_lifetime
annotations. Be clear about why the annotation is needed and which annotation
should be used.
'@preconcurrency' imports open up memory safety holes with respect to
Sendable, which are diagnosed under strict memory safety + strict
concurrency checking. Allow one to write '@unsafe' on those imports to
silence the diagnostic about it.
The concrete nesting limit, which defaults to 30, catches
things like A == G<A>. However, with something like
A == (A, A), you end up with an exponential problem size
before you hit the limit.
Add two new limits.
The first is the total size of the concrete type, counting
all leaves, which defaults to 4000. It can be set with the
-requirement-machine-max-concrete-size= frontend flag.
The second avoids an assertion in addTypeDifference() which
can be hit if a certain counter overflows before any other
limit is breached. This also defaults to 4000 and can be set
with the -requirement-machine-max-type-differences= frontend flag.
Initially, the compiler rejected building dependencies that contained OS
versions in an invalid range. However, this happens to be quite
disruptive, so instead allow it and request that these versions be
implicitly bumped based on what `llvm::Triple::getCanonicalVersionForOS`
computes.
resolves: rdar://153205856
When the CustomAvailability experimental feature is enabled, make it an error
to specify an unrecognized availability domain name. Also, add these
diagnostics to a diagnostic group so that developers can control their behavior
when they are warnings.
Resolves rdar://152741624.
Currently the note is going to point to the "callee" but that is
incorrect when the failure is related to an argument of a call.
Detect this situation in `RValueTreatedAsLValueFailure::diagnoseAsNote`
and produce a correct note.
Resolves: rdar://150689994
No warnings with minimal checking, warnings with `strict-concurrency=complete` and
if declaration is `@preconcurrency` until next major swift version.
Resolves: rdar://151911135
Resolves: https://github.com/swiftlang/swift/issues/81739
Unlike with implicitly-built modules (prior to Swift 6 mode), explicitly-built modules require that all search paths be specified explicitly and no longer inherit search paths serialized into discovered Swift binary modules. This behavior was never intentional and is considered a bug. This change adds a diagnostic note to a scan failure: for each binary Swift module dependency, the scanner will attempt to execute a dependency scanning query for each serialized search path inside that module. If such diagnostic query returns a result, a diagnostic will be emitted to inform the user that the dependency may be found in the search path configuration of another Swift binary module dependency, specifying which search path contains the "missing" module, and stating that such search paths are not automatically inherited by the current compilation.
The proposal states that this should work, but this was never
implemented:
protocol P<A> {
associatedtype A
}
struct S: P<Int> {}
- Fixes https://github.com/swiftlang/swift/issues/62906.
- Fixes rdar://91842338.
The migration to `MemberImportVisibility` can be performed mechanically by
adding missing import declarations, so offer automatic migration for the
feature.
Resolves rdar://151931597.
Consider an `@_alwaysEmitIntoClient` function and a custom derivative
defined
for it. Previously, such a combination resulted different errors under
different
circumstances.
Sometimes, there were linker errors due to missing derivative function
symbol -
these occurred when we tried to find the derivative in a module, while
it
should have been emitted into client's code (and it did not happen).
Sometimes, there were SIL verification failures like this:
```
SIL verification failed: internal/private function cannot be serialized or serializable: !F->isAnySerialized() || embedded
```
Linkage and serialization options for the derivative were not handled
properly,
and, instead of PublicNonABI linkage, we had Private one which is
unsupported
for serialization - but we need to serialize `@_alwaysEmitIntoClient`
functions
so the client's code is able to see them.
This patch resolves the issue and adds proper handling of custom
derivatives
of `@_alwaysEmitIntoClient` functions. Note that either both the
function and
its custom derivative or none of them should have
`@_alwaysEmitIntoClient`
attribute, mismatch in this attribute is not supported.
The following cases are handled (assume that in each case client's code
uses
the derivative).
1. Both the function and its derivative are defined in a single file in
one module.
2. Both the function and its derivative are defined in different files
which
are compiled to a single module.
3. The function is defined in one module, its derivative is defined in
another
module.
4. The function and the derivative are defined as members of a protocol
extension in two separate modules - one for the function and one for the
derivative. A struct conforming the protocol is defined in the third
module.
5. The function and the derivative are defined as members of a struct
extension in two separate modules - one for the function and one for the
derivative.
The changes allow to define derivatives for methods of `SIMD`.
Fixes#54445
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Implements SE-0460 -- the non-underscored version of @specialized.
It allows to specify "internal" (not abi affecting) specializations.
rdar://150033316
