To represent the abstracted interface of an opaque type, we need a generic signature that refines
the outer context generic signature with an additional generic parameter representing the underlying
type and its exposed constraints. Opaque types also need to be keyed by their originating decl, so
that we can treat values of the same opaque type as the same. When we check a FuncDecl with an
opaque type specified as its return type, create an OpaqueTypeDecl and associate it with the
originating decl. (A representation for *types* derived from the opaque decl will come next.)
`#assert` is a new static assertion statement that will let us write
tests for the new constant evaluation infrastructure that we are working
on. `#assert` works by lowering to a `Builtin.poundAssert` SIL
instruction. The constant evaluation infrastructure will look for these
SIL instructions, const-evaluate their conditions, and emit errors if
the conditions are non-constant or false.
This commit implements parsing, typechecking and SILGen for `#assert`.
Use ExtensionDecl::getExtendedNominal() to wire up extensions to their
nominal types early in type checking (the bindExtensions()) operation,
rather than going through type validation to do so.
Introduce ExtensionDecl::getExtendedNominal() to provide the nominal
type declaration that the extension declaration extends. Move most
of the existing callers of the callers to getExtendedType() over to
getExtendedNominal(), because they don’t need the full type information.
ExtensionDecl::getExtendedNominal() is itself not very interesting yet,
because it depends on getExtendedType().
For now, the accessors have been underscored as `_read` and `_modify`.
I'll prepare an evolution proposal for this feature which should allow
us to remove the underscores or, y'know, rename them to `purple` and
`lettuce`.
`_read` accessors do not make any effort yet to avoid copying the
value being yielded. I'll work on it in follow-up patches.
Opaque accesses to properties and subscripts defined with `_modify`
accessors will use an inefficient `materializeForSet` pattern that
materializes the value to a temporary instead of accessing it in-place.
That will be fixed by migrating to `modify` over `materializeForSet`,
which is next up after the `read` optimizations.
SIL ownership verification doesn't pass yet for the test cases here
because of a general fault in SILGen where borrows can outlive their
borrowed value due to being cleaned up on the general cleanup stack
when the borrowed value is cleaned up on the formal-access stack.
Michael, Andy, and I discussed various ways to fix this, but it seems
clear to me that it's not in any way specific to coroutine accesses.
rdar://35399664
Now, an AbstractFunctionDecl always stores a single parameter list.
Furthermore, ConstructorDecl and DestructorDecl always store a
ParamDecl for 'self'.
FuncDecl only has a 'self' if it is a member of a nominal type or
extension, so we tail-allocate the storage for it.
A better approach would be to split off ASTScopeKind::AbstractFunctionSelf
from ASTScopeKind::AbstractFunctionParams, but for now, hack things up at
the boundary to match the old behavior.
The storage kind has been replaced with three separate "impl kinds",
one for each of the basic access kinds (read, write, and read/write).
This makes it far easier to mix-and-match implementations of different
accessors, as well as subtleties like implementing both a setter
and an independent read/write operation.
AccessStrategy has become a bit more explicit about how exactly the
access should be implemented. For example, the accessor-based kinds
now carry the exact accessor intended to be used. Also, I've shifted
responsibilities slightly between AccessStrategy and AccessSemantics
so that AccessSemantics::Ordinary can be used except in the sorts of
semantic-bypasses that accessor synthesis wants. This requires
knowing the correct DC of the access when computing the access strategy;
the upshot is that SILGenFunction now needs a DC.
Accessor synthesis has been reworked so that only the declarations are
built immediately; body synthesis can be safely delayed out of the main
decl-checking path. This caused a large number of ramifications,
especially for lazy properties, and greatly inflated the size of this
patch. That is... really regrettable. The impetus for changing this
was necessity: I needed to rework accessor synthesis to end its reliance
on distinctions like Stored vs. StoredWithTrivialAccessors, and those
fixes were exposing serious re-entrancy problems, and fixing that... well.
Breaking the fixes apart at this point would be a serious endeavor.
* Implement #warning and #error
* Fix #warning/#error in switch statements
* Fix AST printing for #warning/#error
* Add to test case
* Add extra handling to ParseDeclPoundDiagnostic
* fix dumping
* Consume the right paren even in the failure case
* Diagnose extra tokens on the same line after a diagnostic directive
This has three principal advantages:
- It gives some additional type-safety when working
with known accessors.
- It makes it significantly easier to test whether a declaration
is an accessor and encourages the use of a common idiom.
- It saves a small amount of memory in both FuncDecl and its
serialized form.
Allow instance properties and methods to be referenced from
within a lazy property initializer, with or without explicit
'self.' qualification.
The old behavior in Swift 3 was an incredible combination
of odd quirks:
- If the lazy property had an explicitly-written type, it was
possible to reference instance members from the initializer
expression by explicitly prefixing 'self.'.
- However, if the lazy property type is inferred, it would
first be type checked in the initializer context, which
has no 'self' available.
- Unqualified references to instance members did not work
at all, because name lookup thought the "location" of the
lookup was outside of the body of the getter.
- Unqualified references to static properties worked, however
unqualified references to static methods did not, and
produced a bogus diagnostic, because one part of the name
lookup code thought that initializers were "instance
context" and another thought they were "static context".
This patch improves on the old behavior with the following
fixes:
- Give PatternBindingInitializers associated with lazy
properties an implicit 'self' declaration for use by
name lookup.
- In order to allow "re-parenting" the initializer after it
has been type checked into the body of the getter, "steal"
the initializer's 'self' when buiding the getter.
- Fix up name lookup and make it aware of the implicit
'self' decl of a PatternBindingInitializer.
This improves upon an earlier fix for this issue by Doug Gregor
which only worked with ASTScope enabled; the new fix is more
general and shares logic between the two name lookup
implementations.
Fixes <rdar://problem/16888679>, <https://bugs.swift.org/browse/SR-48>,
<https://bugs.swift.org/browse/SR-2203>,
<https://bugs.swift.org/browse/SR-4663>, and the countless other
dupes of this issue.
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
As such, we no longer insert two placeholders for initializers that
need two vtable slots; instead we record that in the
MissingMemberDecl. I can see MissingMemberDecl growing to be something
we'd actually show to users, that can be used for other kinds of
declarations that don't have vtable entries, but for now I'm not going
to worry about any of that.
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.
Changes:
* Terminate all namespaces with the correct closing comment.
* Make sure argument names in comments match the corresponding parameter name.
* Remove redundant get() calls on smart pointers.
* Prefer using "override" or "final" instead of "virtual". Remove "virtual" where appropriate.
This lookup causes recursion that the rest of the name lookup
machinery cannot yet handle, breaking code that is currently
well-formed. Back off of this lookup temporarily.
As in non-local scopes, local types and functions are generally
visible anywhere within enclosing braces, and it is up to capture
analysis to determine whether these entities attempt to capture an
entity that isn't guaranteed to be available.
While the use of a local property from within its own accessors is a
bit dubious, Swift 3 only warned on it, so model the existing lookup
behavior in the scope map.
Once top-level code is introduced into a source file, turn the source
file itself into a continuation, so that subsequent declarations have
proper scope information. This means we get proper scope information
for, e.g., pattern bindings and guard statements in top-level code, so
that a 'guard' at top level is a parent of all subsequent code,
including (e.g.) function declarations that might capture variables
introduced by the guard.
Continuations are now handled by more explicitly passing them down
from parent nodes to the child nodes that can accept them, and the
source file itself is modeled as a continuation as soon as the first
top-level code declaration is encountered.
Rather than trying to specifically model local declarations of
functions and types with a "local declaration" scope, which we
introduced when we saw one of these entities with a local DeclContext,
use a more consistency scheme where:
1) we always describe a type declaration with a TypeDecl scope and an
(abstract) function declaration with an AbstractFunctionDecl scope,
and
2) either of those scopes can steal the continuation from their
parent;
This modeling is another step toward supporting top-level code.
Record the active continuation scope for each scope. When we expand a
child node that introduces name that would be visible in a
continuation, we "steal" the continuation from the parent, so the
child takes over the responsibility of handling the continuation.
A continuation is initially introduced by expanding a brace statement,
where the continuation is itself. The eliminates a DRY violation
between the initial expansion of BraceStmts and
enumerateContinuationScopes() that's been nagging at me.
At present, this should be NFC, but it should make modeling top-level
code more reasonable.
The scope map relies fairly deeply on having reasonable source ranges
for AST nodes. Fix the construction and query of source ranges in a
few places throughout the parser and AST to provide stronger
invariants.
Lazy property initializers can refer to 'self' either directly or
implicitly (via references to instance members). Model this in
ASTScope-based unqualified name lookup.
Note that the modeling of 'self' with the current name lookup
mechanism is broken, so when ASTScope-based unqualified name lookup is
enabled, it fixes SR-2203, rdar://problem/16954496, and the many dupes
of the latter.
Semantic analysis produces implicit accessors that can show up before initializers (e.g., for initializers), and it’s reasonable for ill-formed code to do this as well, so be more tolerant of ordering issues here.
For methods/initializers/deinitializers, modeling the scope of a
function body allows us to correctly introduce instance member lookup
relative to 'self'. Do so so that we can resolve unqualified name
lookup within methods based on the implicit 'self'.
Introduce an operation that produces the set of local declarations
that are newly introduced by a given AST scope. This is a building
block of unqualified name lookup, which walks upward in the tree
(e.g., from children to parents) looking for declarations that have
been made visible at each step.
