Lookups like Builtin::Int64 were failing because BuiltinUnit rejected all unqualified lookups. Make it allow unqualified lookups with a module selector.
The `_Concurrency` and `_StringProcessing` modules are implementation details of the standard library; to developers, their contents should behave as though they are declared directly within module `Swift`. This is the exact same behavior we expect of cross-import overlays, so treat these modules as though they are cross-import overlays with no bystanding module.
Because these modules don’t re-export the standard library, it’s also necessary to treat `Swift` as a separately imported overlay of itself; do so and make that actually work.
Some functions like memchr are defined both in libc++ and libc.
Including both would result in ambiguous references at the call sites.
This is worked around by an attribute that tells the compiler to prefer
one overload over the others. This attribute was not interpreted by
Swift. As a result, importing both libc and libc++ and calling such
functions resulted in compilation errors due to ambiguous overloads.
This PR modifies the lookup logic to exclude the non-preferred Clang
functions from the overload set whenever a preferred overload is
available.
rdar://152192945
Sema now type-checks the alternate ABI-providing decls inside of @abi attributes.
Making this work—particularly, making redeclaration checking work—required making name lookup aware of ABI decls. Name lookup now evaluates both API-providing and ABI-providing declarations. In most cases, it will filter ABI-only decls out unless a specific flag is passed, in which case it will filter API-only decls out instead. Calls that simply retrieve a list of declarations, like `IterableDeclContext::getMembers()` and friends, typically only return API-providing decls; you have to access the ABI-providing ones through those.
As part of that work, I have also added some basic compiler interfaces for working with the API-providing and ABI-providing variants. `ABIRole` encodes whether a declaration provides only API, only ABI, or both, and `ABIRoleInfo` combines that with a pointer to the counterpart providing the other role (for a declaration that provides both, that’ll just be a pointer to `this`).
Decl checking of behavior specific to @abi will come in a future commit.
Note that this probably doesn’t properly exercise some of the new code (ASTScope::lookupEnclosingABIAttributeScope(), for instance); I expect that to happen only once we can rename types using an @abi attribute, since that will create distinguishable behavior differences when resolving TypeReprs in other @abi attributes.
Although I don't plan to bring over new assertions wholesale
into the current qualification branch, it's entirely possible
that various minor changes in main will use the new assertions;
having this basic support in the release branch will simplify that.
(This is why I'm adding the includes as a separate pass from
rewriting the individual assertions)
If an extension isn't imported either directly or via a transitive
(`@_exported`) import, its members should not be visible to name
lookup. Implement this behavior behind the experimental flag
ExtensionImportVisibility.
When performing name lookup for freestanding macros (e.g., after the
`#`), don't allow types to shadow macros from imported libraries.
Fixes rdar://110429368.
This source location will be used to determine whether to add a name lookup
option to exclude macro expansions when the name lookup request is constructed.
Currently, the source location argument is unused.
The macro name resolution in the source lookup cache was only looking at
macros in the current module, meaning that any names introduced by peer
or declaration macros declared in one module but used in another would
not be found by name lookup.
Switch the source lookup cache over to using the same
`forEachPotentialResolvedMacro` API that is used by lookup within
types, so we have consistent name-lookup-level macro resolution in both
places.
... except that would be horribly cyclic, of course, so introduce name
lookup flags to ignore top-level declarations introduced by macro
expansions. This is semantically correct because macro expansions are
not allowed to introduce new macros anyway, because that would have
been a terrible idea.
Fixes rdar://107321469. Peer and declaration macros at module scope
should work a whole lot better now.
This attribute allows to define a pre-specialized entry point of a
generic function in a library.
The following definition provides a pre-specialized entry point for
`genericFunc(_:)` for the parameter type `Int` that clients of the
library can call.
```
@_specialize(exported: true, where T == Int)
public func genericFunc<T>(_ t: T) { ... }
```
Pre-specializations of internal `@inlinable` functions are allowed.
```
@usableFromInline
internal struct GenericThing<T> {
@_specialize(exported: true, where T == Int)
@inlinable
internal func genericMethod(_ t: T) {
}
}
```
There is syntax to pre-specialize a method from a different module.
```
import ModuleDefiningGenericFunc
@_specialize(exported: true, target: genericFunc(_:), where T == Double)
func prespecialize_genericFunc(_ t: T) { fatalError("dont call") }
```
Specially marked extensions allow for pre-specialization of internal
methods accross module boundries (respecting `@inlinable` and
`@usableFromInline`).
```
import ModuleDefiningGenericThing
public struct Something {}
@_specializeExtension
extension GenericThing {
@_specialize(exported: true, target: genericMethod(_:), where T == Something)
func prespecialize_genericMethod(_ t: T) { fatalError("dont call") }
}
```
rdar://64993425
To help consolidate our various types describing imports, this commit moves the following types and methods to Import.h:
* ImplicitImports
* ImplicitStdlibKind
* ImplicitImportInfo
* ModuleDecl::ImportedModule
* ModuleDecl::OrderImportedModules (as ImportedModule::Order)
* ModuleDecl::removeDuplicateImports() (as ImportedModule::removeDuplicates())
* SourceFile::ImportFlags
* SourceFile::ImportOptions
* SourceFile::ImportedModuleDesc
This commit is large and intentionally kept mechanical—nothing interesting to see here.
A request is intended to be a pure function of its inputs. That function could, in theory, fail. In practice, there were basically no requests taking advantage of this ability - the few that were using it to explicitly detect cycles can just return reasonable defaults instead of forwarding the error on up the stack.
This is because cycles are checked by *the Evaluator*, and are unwound by the Evaluator.
Therefore, restore the idea that the evaluate functions are themselves pure, but keep the idea that *evaluation* of those requests may fail. This model enables the best of both worlds: we not only keep the evaluator flexible enough to handle future use cases like cancellation and diagnostic invalidation, but also request-based dependencies using the values computed at the evaluation points. These aforementioned use cases would use the llvm::Expected interface and the regular evaluation-point interface respectively.
When a “separately imported overlay” is added to a SourceFile, two things happen:
1. The direct import of the underlying module is removed from getImports*() by default. It is only visible if the caller passes ImportFilterKind:: ShadowedBySeparateOverlay. This means that non-module-scoped lookups will search _OverlayModule before searching its re-export UnderlyingModule, allowing it to shadow underlying declarations.
2. When you ask for lookupInModule() to look in the underlying module in that source file, it looks in the overlays instead. This means that UnderlyingModule.foo() can find declarations in _OverlayModule.
Removes duplicated logic from the implementations of
FileUnit::lookupValue, and simplifies the interface to
ModuleDecl::lookupValue, where everyone was passing an empty
(non-filtering) access path anyway /except/ during actual lookup from
source code. No functionality change.
Now that the normal name lookup shadowing can handle the module-based
shadowing rules implemented by lookupInModule(), we can drastically
simplify the implementation, replacing the graph traversal with an
iteration over the linearized graph.
Note that in all cases it was either nullptr or ctx.getLazyResolver().
While passing in nullptr might appear at first glance to mean something
("don't type check anything"), in practice we would check for a nullptr
value and pull out ctx.getLazyResolver() instead. Furthermore, with
the lazy resolver going away (at least for resolveDeclSignature() calls),
it won't make sense to do that anymore anyway.
Break up the large 'lookupInModule' function into a class with helper
methods; eliminate parameters that can be inferred from context or
stored as fields; add more comments and 'const'.
No intended functionality change.
Features like `@testable import` change the results produced by name
lookup in the source file with the testable import. What they
/shouldn't/ do is change the results of lookup into the same module
from elsewhere in the import graph...and neither should cached results
from lookup elsewhere in the import graph affect the lookups from the
source file. Encode this difference in the cache used during
module-level name lookup to fix testable imports like this.
(The test case here looks a little contrived because of '@_exported',
but that's how imports are treated in Clang modules and with bridging
headers, so it is in fact a realistic scenario.)
rdar://problem/48890959
AST/LookupVisibleDecls.cpp has a dependency on swiftSema by having doGlobalExtensionLookup call into swift::isExtensionApplied,
and doGlobalExtensionLookup is ultimately used by the other global functions in that file.
Break the cycle by moving the file into the swiftSema library.
With the introduction of special decl names, `Identifier getName()` on
`ValueDecl` will be removed and pushed down to nominal declarations
whose name is guaranteed not to be special. Prepare for this by calling
to `DeclBaseName getBaseName()` instead where appropriate.
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.
The typedef `swift::Module` was a temporary solution that allowed
`swift::Module` to be renamed to `swift::ModuleDecl` without requiring
every single callsite to be modified.
Modify all the callsites, and get rid of the typedef.
