In order to unblock resolution of availability domains during type-checking
instead of parsing, diagnostics about missing or superfluous wildcards in
availability specification lists need to move to Sema.
Eventually, querying the `AvailabilityDomain` associated with an
`AvailabilitySpec` will require invoking a request that takes a `DeclContext`.
This means that any diagnostics related to the domain identified by an
`AvailabilitySpec` need to be emitted during type-checking rather than parsing.
This change migrates several `AvailabilitySpec` diagnostics from Parse to Sema
to unblock further work.
Since resolving the domain of an `@available` attribute is done during type
checking now, diagnostics about unexpected versions for a domain need to be
emitted at that point instead of during parsing. It doesn't make sense to
maintain the special version of this diagnostic that is emitted during parsing
for the universal availability domain only.
Since the domain is now resolved by SemanticAvailableAttrRequest, diagnosing
attributes with invalid combinations of fields for a specific domains needs to
be delayed.
Introduce an `unsafe` expression akin to `try` and `await` that notes
that there are unsafe constructs in the expression to the right-hand
side. Extend the effects checker to also check for unsafety along with
throwing and async operations. This will result in diagnostics like
the following:
10 | func sum() -> Int {
11 | withUnsafeBufferPointer { buffer in
12 | let value = buffer[0]
| | `- note: reference to unsafe subscript 'subscript(_:)'
| |- warning: expression uses unsafe constructs but is not marked with 'unsafe'
| `- note: reference to parameter 'buffer' involves unsafe type 'UnsafeBufferPointer<Int>'
13 | tryWithP(X())
14 | return fastAdd(buffer.baseAddress, buffer.count)
These will come with a Fix-It that inserts `unsafe` into the proper
place. There's also a warning that appears when `unsafe` doesn't cover
any unsafe code, making it easier to clean up extraneous `unsafe`.
This approach requires that `@unsafe` be present on any declaration
that involves unsafe constructs within its signature. Outside of the
signature, the `unsafe` expression is used to identify unsafe code.
This attribute will allow you to specify an alternate version of the declaration used for mangling. It will allow minor adjustments to be made to declarations so long as they’re still compatible at the calling convention level, such as refining isolation or sendability, renaming without breaking ABI, etc.
The attribute is behind the experimental feature flag `ABIAttribute`.
Introduce an attribute to allow unsafe code within the annotated
declaration without presenting an unsafe interface to users. This is,
by its nature, and unsafe construct, and is used to document where
unsafe behavior is encapsulated in safe constructs.
There is an optional message that can be used as part of an audit
trail.
Type annotations for instruction operands are omitted, e.g.
```
%3 = struct $S(%1, %2)
```
Operand types are redundant anyway and were only used for sanity checking in the SIL parser.
But: operand types _are_ printed if the definition of the operand value was not printed yet.
This happens:
* if the block with the definition appears after the block where the operand's instruction is located
* if a block or instruction is printed in isolation, e.g. in a debugger
The old behavior can be restored with `-Xllvm -sil-print-types`.
This option is added to many existing test files which check for operand types in their check-lines.
This started out as a crash, where an expression macro could not be
defined in terms of one of the builtin macros (e.g., `#line`), because
we were expecting a macro expansion expression but didn't get one.
Easy fix.
However, this uncovered a second bug, which is that we couldn't handle
an expression macro expansino to `#line`. This is because we were
parsing the macro expansion buffer as "top level items", which treats
`#line` at the start of a line as a deprecated alias of
`#sourceLocation`. Switch over to parsing a single expression in these
contexts, and fix up an issue where `#isolation` didn't even have that
expression.
Fixes rdar://139372780.
With the `CoroutineAccessors` feature, `read` is allowed along with
`get` and `set`; alter the diagnostic that's issued when a disallowed
introducer is listed in the requirement list to indicate that `read` is
one of those which are valid, but only when the feature is enabled.
For now this will only be used for HopToMainActorIfNeeded thunks. I am creating
this now since in the past there has only been one option for creating
thunks... to create the thunk in SILGen using SILGenThunk. This code is hard to
test and there is a lot of it. By using an instruction here we get a few benefits:
1. We decouple SILGen from needing to generate new kinds of thunks. This means
that SILGenThunk does not need to expand to handle more thunks.
2. All thunks implemented via ThunkInst will be easy to test in a decoupled way
with SIL tests.
3. Even though this stabilizes the patient, we still have many thunks in SILGen
and various parts of the compiler. Over time, we can swap to this model,
allowing us to hopefully eventually delete SILGenThunk.
Previously, missing return diagnostics for unreachable subscripts
differed from the treatment unreachable functions received, leading to
inconsistent diagnostic behavior. This change removes the responsibility
for handling the relevant diagnostics from the AST code, in favor of the
diagnostics implemented via the SIL optimizer. Additionally, where the
AST-generation code would previously have diagnosed a missing return for
an implicit empty getter, it will now admit as valid, deferring the
missing return diagnostics to the later SIL passes.
Out of an abundance of caution, we:
1. Left in parsing support for transferring but internally made it rely on the
internals of sending.
2. Added a warning to tell people that transferring was going to
be removed very soon.
Now that we have given people some time, remove support for parsing
transferring.
rdar://130253724
Previously we would only diagnose and recover for
invalid tokens following a `#if` body for the decl
and postfix expression case. Sink this logic into
`parseIfConfigRaw`, ensuring that we do this for
all `#if` cases. This requires propagating the
context we're parsing in to customize the
diagnostic.
We are leaving this as an open part of the design space. In the mean time if
people need a +0 parameter, they can use __shared with sending.
rdar://129116182
A few things:
1. Internally except for in the parser and the clang importer, we only represent
'sending'. This means that it will be easy to remove 'transferring' once enough
time has passed.
2. I included a warning that suggested to the user to change 'transferring' ->
'sending'.
3. I duplicated the parsing diagnostics for 'sending' so both will still get
different sets of diagnostics for parsing issues... but anywhere below parsing,
I have just changed 'transferring' to 'sending' since transferring isn't
represented at those lower levels.
4. Since SendingArgsAndResults is always enabled when TransferringArgsAndResults
is enabled (NOTE not vis-a-versa), we know that we can always parse sending. So
we import "transferring" as "sending". This means that even if one marks a
function with "transferring", the compiler will guard it behind a
SendingArgsAndResults -D flag and in the imported header print out sending.
rdar://128216574
Previously, diagnostics for arguments of platform conditions (e.g.
'os(macOS)') used to point the condition name position instead of the
argument position.
Adjust the position to the start of the argument.
rdar://124160048
Our standard conception of suppressible features assumes we should
always suppress the feature if the compiler doesn't support it.
This presumes that there's no harm in suppressing the feature, and
that's a fine assumption for features that are just adding information
or suppressing new diagnostics. Features that are semantically
relevant, maybe even ABI-breaking, are not a good fit for this,
and so instead of reprinting the decl with the feature suppressed,
we just have to hide the decl entirely. The missing middle here
is that it's sometimes useful to be able to adopt a type change
to an existing declaration, and we'd like older compilers to be
able to use the older version of the declaration. Making a type
change this way is, of course, only really acceptable for
@_alwaysEmitIntoClient declarations; but those represent quite a
few declarations that we'd like to be able to refine the types of.
Rather than trying to come up with heuristics based on
@_alwaysEmitIntoClient or other sources of information, this design
just requires the declaration to opt in with a new attribute,
@_allowFeatureSuppress. When a declaration opts in to suppression
for a conditionally-suppressible feature, the printer uses the
suppression serially-print-with-downgraded-options approach;
otherwise it uses the print-only-if-feature-is-available approach.
Instead it is a bit on ParamDecl and SILParameterInfo. I preserve the consuming
behavior by making it so that the type checker changes the ParamSpecifier to
ImplicitlyCopyableConsuming if we have a default param specifier and
transferring is set. NOTE: The user can never write ImplicitlyCopyableConsuming.
NOTE: I had to expand the amount of flags that can be stored in ParamDecl so I
stole bits from TypeRepr and added some logic for packing option bits into
TyRepr and DefaultValue.
rdar://121324715
This should allow us to eventually simplify parsing of simple string literals in the new parse by not having to handle indentation of multiline string literals.
