These two requests are effectively doing the same thing to two
different cases within CatchNode. Unify the requests into a single
request, ExplicitCaughtTypeRequest, which operates on a CatchNode.
This also moves the logic for closures with explicitly-specified throws
clauses into the same request, taking it out of the constraint system.
Some notes:
This is not emitted by SILGen. This is just intended to be used so I can write
SIL test cases for transfer non sendable. I did this by adding an
ActorIsolationCrossing field to all FullApplySites rather than adding it into
the type system on a callee. The reason that this makes sense from a modeling
perspective is that an actor isolation crossing is a caller concept since it is
describing a difference in between the caller's and callee's isolation. As a
bonus it makes this a less viral change.
For simplicity, I made it so that the isolation is represented as an optional
modifier on the instructions:
apply [callee_isolation=XXXX] [caller_isolation=XXXX]
where XXXX is a printed representation of the actor isolation.
When neither callee or caller isolation is specified then the
ApplyIsolationCrossing is std::nullopt. If only one is specified, we make the
other one ActorIsolation::Unspecified.
This required me to move ActorIsolationCrossing from AST/Expr.h ->
AST/ActorIsolation.h to work around compilation issues... Arguably that is where
it should exist anyways so it made sense.
rdar://118521597
For any operation that can throw an error, such as calls, property
accesses, and non-exhaustive do..catch statements, record the thrown
error type along with the conversion from that thrown error to the
error type expected in context, as appropriate. This will prevent
later stages from having to re-compute the conversion sequences.
Type checking a default argument expression will compute the required
actor isolation for evaluating that argument value synchronously. Actor
isolation checking is deferred to the caller; it is an error to use a
default argument from across isolation domains.
Currently gated behind -enable-experimental-feature IsolatedDefaultArguments.
Lower the thrown error type into the SIL function type. This requires
very little code because the thrown error type was already modeled as
a SILResultInfo, which carries type information. Note that this
lowering does not yet account for error types that need to passed
indirectly, but we will need to do so for (e.g.) using resilient error
types.
Teach a few places in SIL generation not to assume that thrown types
are always the existential error type, which primarily comes down to
ensuring that rethrow epilogues have the thrown type of the
corresponding function or closure.
Teach throw emission to implicitly box concrete thrown errors in the
error existential when needed to satisfy the throw destination. This
is a temporary solution that helps translate typed throws into untyped
throws, but it should be replaced by a better modeling within the AST
of the points at which thrown errors are converted.
Parse typed throw specifiers as `throws(X)` in every place where there
are effects specified, and record the resulting thrown error type in
the AST except the type system. This includes:
* `FunctionTypeRepr`, for the parsed representation of types
* `AbstractFunctionDecl`, for various function-like declarations
* `ClosureExpr`, for closures
* `ArrowExpr`, for parsing of types within expression context
This also introduces some serialization logic for the thrown error
type of function-like declarations, along with an API to extract the
thrown interface type from one of those declarations, although right
now it will either be `Error` or empty.
getClosureActorIsolation.
This is preparation for changing AbstractClosureExpr to store
ActorIsolation instead of ClosureActorIsolation, and convert to
ClosureActorIsolation when needed to allow incrementally updating
callers. This change is NFC.
This PR refactors the ASTDumper to make it more structured, less mistake-prone, and more amenable to future changes. For example:
```cpp
// Before:
void visitUnresolvedDotExpr(UnresolvedDotExpr *E) {
printCommon(E, "unresolved_dot_expr")
<< " field '" << E->getName() << "'";
PrintWithColorRAII(OS, ExprModifierColor)
<< " function_ref=" << getFunctionRefKindStr(E->getFunctionRefKind());
if (E->getBase()) {
OS << '\n';
printRec(E->getBase());
}
PrintWithColorRAII(OS, ParenthesisColor) << ')';
}
// After:
void visitUnresolvedDotExpr(UnresolvedDotExpr *E, StringRef label) {
printCommon(E, "unresolved_dot_expr", label);
printFieldQuoted(E->getName(), "field");
printField(E->getFunctionRefKind(), "function_ref", ExprModifierColor);
if (E->getBase()) {
printRec(E->getBase());
}
printFoot();
}
```
* Values are printed through calls to base class methods, rather than direct access to the underlying `raw_ostream`.
* These methods tend to reduce the chances of bugs like missing/extra spaces or newlines, too much/too little indentation, etc.
* More values are quoted, and unprintable/non-ASCII characters in quoted values are escaped before printing.
* Infrastructure to label child nodes now exists.
* Some weird breaks from the normal "style", like `PatternBindingDecl`'s original and processed initializers, have been brought into line.
* Some types that previously used ad-hoc dumping functions, like conformances and substitution maps, are now structured similarly to the dumper classes.
* I've fixed the odd dumping bug along the way. For example, distributed actors were only marked `actor`, not `distributed actor`.
This PR doesn't change the overall style of AST dumps; they're still pseudo-S-expressions. But the logic that implements this style is now isolated into a relatively small base class, making it feasible to introduce e.g. JSON dumping in the future.
These allow multi-statement `if`/`switch` expression
branches that can produce a value at the end by
saying `then <expr>`. This is gated behind
`-enable-experimental-feature ThenStatements`
pending evolution discussion.
Specifically, the two routines we were importing relatively were:
1. TypeChecker::conformsToProtocol. I moved this onto a helper routine on
SILType.
2. swift::findOriginalValueType(Expr *). This routine just looks through various
implicit conversions to find the original underlying type. I moved it to a
helper method on Expr.
Previously we would only base the start loc on the
`SubExpr`, but that isn't set until CSApply. Change
it to take both `SubExpr` and `Body`'s source range
into account.
Also tighten up the invariant that a TapExpr must
be created with a non-null BraceStmt.
Reformatting everything now that we have `llvm` namespaces. I've
separated this from the main commit to help manage merge-conflicts and
for making it a bit easier to read the mega-patch.
This is phase-1 of switching from llvm::Optional to std::optional in the
next rebranch. llvm::Optional was removed from upstream LLVM, so we need
to migrate off rather soon. On Darwin, std::optional, and llvm::Optional
have the same layout, so we don't need to be as concerned about ABI
beyond the name mangling. `llvm::Optional` is only returned from one
function in
```
getStandardTypeSubst(StringRef TypeName,
bool allowConcurrencyManglings);
```
It's the return value, so it should not impact the mangling of the
function, and the layout is the same as `std::optional`, so it should be
mostly okay. This function doesn't appear to have users, and the ABI was
already broken 2 years ago for concurrency and no one seemed to notice
so this should be "okay".
I'm doing the migration incrementally so that folks working on main can
cherry-pick back to the release/5.9 branch. Once 5.9 is done and locked
away, then we can go through and finish the replacement. Since `None`
and `Optional` show up in contexts where they are not `llvm::None` and
`llvm::Optional`, I'm preparing the work now by going through and
removing the namespace unwrapping and making the `llvm` namespace
explicit. This should make it fairly mechanical to go through and
replace llvm::Optional with std::optional, and llvm::None with
std::nullopt. It's also a change that can be brought onto the
release/5.9 with minimal impact. This should be an NFC change.
'MacroExpansionDecl' and 'MacroExpansionExpr' have many common methods.
Introduce a common base class 'FreestandingMacroExpansion' that holds
'MacroExpansionInfo'.
Factor out common expansion logic to 'evaluateFreestandingMacro'
function that resembles 'evaluateAttachedMacro'.
Before this change it was possible to:
1. Call mutating methods on a consume result.
2. assign into a consume (e.x.: var x = ...; (consume x) = value.
From an implementation perspective, this involved just taking the logic I
already used for the CopyExpr and reusing it for ConsumeExpr with some small
tweaks.
rdar://109479440
Some notes:
1. I implemented this as a contextual keyword that can only apply directly to
lvalues. This ensures that we can still call functions called copy, define
variables named copy, etc. I added tests for both the c++ and swift-syntax based
parsers to validate this. So there shouldn't be any source breaks.
2. I did a little bit of type checker work to ensure that we do not treat
copy_expr's result as an lvalue. Otherwise, one could call mutating functions on
it or assign to it, which we do not want since the result of copy_value is
3. As expected, by creating a specific expr, I was able to have much greater
control of the SILGen codegen and thus eliminate extraneous copies and other
weirdness than if we used a function and had to go through SILGenApply.
rdar://101862423
Sometimes we build a `MacroExpansionDecl` from a `MacroExpansionExpr`.
Sometimes we do it the other way. In both cases, we risk the two
copies of must-by-shared data (macro arguments, resolved macro
reference, etc.) getting out-of-sync.
Instead, share the storage between the two representations when we
create one from the other, so that they cannot get out-of-sync. This
allows us to eliminate the extremely-dodgy `cacheOutput` call earlier.
Allow freestanding macros to be used at top-level.
- Parse top-level `#…` as `MacroExpansionDecl` when we are not in scripting mode.
- Add macro expansion decls to the source lookup cache with name-driven lazy expansion. Not supporting arbitrary name yet.
- Experimental support for script mode and brace-level declaration macro expansions: When type-checking a `MacroExpansionExpr`, assign it a substitute `MacroExpansionDecl` if the macro reference resolves to a declaration macro. This doesn’t work quite fully yet and will be enabled in a future fix.
Introduce SingleValueStmtExpr, which allows the
embedding of a statement in an expression context.
This then allows us to parse and type-check `if`
and `switch` statements as expressions, gated
behind the `IfSwitchExpression` experimental
feature for now. In the future,
SingleValueStmtExpr could also be used for e.g
`do` expressions.
For now, only single expression branches are
supported for producing a value from an
`if`/`switch` expression, and each branch is
type-checked independently. A multi-statement
branch may only appear if it ends with a `throw`,
and it may not `break`, `continue`, or `return`.
The placement of `if`/`switch` expressions is also
currently limited by a syntactic use diagnostic.
Currently they're only allowed in bindings,
assignments, throws, and returns. But this could
be lifted in the future if desired.
