Resolves: https://bugs.swift.org/browse/SR-4426
* Make IfConfigDecl be able to hold ASTNodes
* Parse #if as IfConfigDecl
* Stop enclosing toplevel #if into TopLevelCodeDecl.
* Eliminate IfConfigStmt
This introduces a few unfortunate things because the syntax is awkward.
In particular, the period and following token in \.[a], \.? and \.! are
token sequences that don't appear anywhere else in Swift, and so need
special handling. This is somewhat compounded by \foo.bar.baz possibly
being \(foo).bar.baz or \(foo.bar).baz (parens around the type), and,
furthermore, needing to distinguish \Foo?.bar from \Foo.?bar.
rdar://problem/31724243
Fixes:
https://bugs.swift.org/browse/SR-3455https://bugs.swift.org/browse/SR-3663https://bugs.swift.org/browse/SR-4032https://bugs.swift.org/browse/SR-4031
Now, compilation conditions are validated at first, then evaluated. Also,
in non-Swift3 mode, '&&' now has higher precedence than '||'.
'A || B && C || D' are evaluated as 'A || (B && C) || D'.
Swift3 source breaking changes:
* [SR-3663] This used to be accepted and evaluate to 'true' because of short
circuit without any validation.
#if true || true * 12 = try Anything is OK?
print("foo")
#endif
In this change, remaining expressions are properly validated and
diagnosed if it's invalid.
* [SR-4031] Compound name references are now diagnosed as errors.
e.g. `#if os(foo:bar:)(macOS)` or `#if FLAG(x:y:)`
Swift3 compatibility:
* [SR-3663] The precedence of '||' and '&&' are still the same and the
following code evaluates to 'true'.
#if false || true && false
print("foo")
#endif
foo(_: 3) is equivalent to foo(3), so calling a function that has _ as
an argument label (func foo(`_`: 3)) still requires the _ to be
escaped. Before this patch, the compiler would suggest removing the `s,
even though that changes behaviour.
Fixes rdar://problem/31077797.
A lot of files transitively include Expr.h, because it was
included from SILInstruction.h, SILLocation.h and SILDeclRef.h.
However in reality most of these files don't do anything
with Exprs, especially not anything in IRGen or the SILOptimizer.
Now we're down to 171 files in the frontend which depend on
Expr.h, which is still a lot but much better than before.
This biggest change is:
- LayoutConstraintInfo is now a FoldingSetNode, which allows for proper canonicalization of LayoutConstraints. This is important for the correctness of type comparisons if types contain layout constraints.
No functionality changes from the client's point of view.
Add diagnostics to fix decls with consecutive identifiers. This applies to
types, properties, variables, and enum cases. The diagnostic adds a camel-cased option if it is different than the first option.
https://bugs.swift.org/browse/SR-3599
The new `@_specialize` attribute has a syntax like this:
```swift
@_specialize(exported: true, kind: full, where K == Int, V == Int)
@_specialize(exported: false, kind: partial, where K: _Trivial64)
func dictFunction<K, V>(dict: Dictionary<K, V>) {
}
```
If `exported` is set, the corresponding specialization would have a public visibility and can be used by clients.
If `exported` is omitted, it's value is assumed to be `false`.
If `kind` is `full` it means a full specialization.
If `kind` is `partial` it means a partial specialization.
If `kind` is omitted, its value is assumed to be `full`.
Parsing declaration list (e.g. member list of nominal decl) is very
different from comma separated list, because it's elements are separated with
new-line or semi-colon. There's no good reason to consolidate them.
Also, declaration list in 'extension' or inside of decl '#if' didn't
emit diagnostics for consecutive declarations on a line.
class C {
#if true
var value: Int = 42 func foo() {}
#endif
}
extension C {
func bar() {} subscript(i: Int) -> Int {
return 24
}
}
This change consolidates declaration list parsing for
members of nominal decls, extensions, and inside of '#if'.
In addition, removed unnecessary property 'TrailingSemiLoc' from decl.
This reverts the contents of #5778 and replaces it with a far simpler
implementation of condition resolution along with canImport. When
combined with the optimizations in #6279 we get the best of both worlds
with a performance win and a simpler implementation.
This completely removes Parse’s ability to make any judgement calls
about compilation conditions, instead the parser-relevant parts of
‘evaluateConditionalCompilationExpr’ have been moved into
‘classifyConditionalCompilationExpr’ where they exist to make sure only
decls that we want to parse actually parse later.
The condition-evaluation parts have been moved into NameBinding in the
form of a Walker that evaluates and collapses IfConfigs. This walker
is meant as an homage to PlaygroundLogger. It should probably be
factored out into a common walker at some point in the future.
* Removed `parseConstructorArguments()`, unified with
`parseSingleParameterClause()`.
* Use `parseSingleParameterClause()` from `parseFunctionSignature()`, so
that we can share the recovery code.
* Removed `isFirstParameterClause` parameter from `mapParsedParameters`,
because it's predictable from `paramContext`.
Use a syntax that declares the layout's generic parameters and fields,
followed by the generic arguments to apply to the layout:
{ var Int, let String } // A concrete box layout with a mutable Int
// and immutable String field
<T, U> { var T, let U } <Int, String> // A generic box layout,
// applied to Int and String
// arguments
