Re-implement operator and precedencegroup decl
lookup to use `namelookup::getAllImports` and
existing decl shadowing logic. This allows us to
find operator decls through `@_exported` imports,
prefer operator decls defined in the same module
over imported decls, and fixes a couple of other
subtle issues.
Because this new implementation is technically
source breaking, as we can find multiple results
where we used to only find one result, it's placed
behind the new Frontend flag
`-enable-new-operator-lookup` (with the aim of
enabling it by default when we get a new language
mode).
However the new logic will always be used if the
result is unambiguous. This means that e.g
`@_exported` operators will be instantly available
as long as there's only one candidate. If multiple
candidates are found, we fall back to the old
logic.
Resolves SR-12132.
Resolves rdar://59198796.
We weren't handling this case, so their generated interfaces / doc info
wouldn't include symbols from the cross-import overlays, and we wouldn't
map the underscored cross-import overlay name back to the declaring
framework's name in cusor-info, completion results or when indexing.
Resolves rdar://problem/62138551
Add ModuleImplicitImportsRequest, which computes
the modules that should be implicitly imported by
each file of a given module. Use this request in
import resolution to add all the necessary
implicit imports.
The request computes the implicit imports by
consulting the ImplicitImportInfo, which ModuleDecl
can now be created with. This allows us to remove
uses of `SourceFile::addImports` in favor of
adding modules needed to be implicitly imported to
the ImplicitImportInfo.
`SynthesizedFileUnit` is a container for synthesized declarations. Currently, it
only supports module-level declarations.
It is used by the SIL differentiation transform, which generates implicit struct
and enum declarations.
Switch the direct operator lookup logic over to
querying the SourceLookupCache, then switch the
main operator lookup logic over to calling the
direct lookup logic rather than querying the
operator maps on the SourceFile.
This then allows us to remove the SourceFile
operator maps, in addition to the logic from
NameBinding that populated them. This requires
redeclaration checking to be implemented
separately.
Finally, to compensate for the caching that the old
operator maps were providing for imported results,
turn the operator lookup requests into cached
requests.
Query the SourceLookupCache for the operator decls,
and use ModuleDecl::getOperatorDecls for both
frontend stats and to clean up some code
completion logic.
In addition, this commit switches getPrecedenceGroups
over to querying SourceLookupCache.
We previously computed cross-imports by comparing N transitive imports against N transitive imports. This is wasteful, because at least one of the two modules in a pair has to actually declare a cross-import overlay for us to discover one, and the vast majority of modules don’t declare any.
This commit makes us instead compare N transitive imports against M transitive imports which are known to declare at least one cross-import overlay. Since N is potentailly in the thousands while M is perhaps in the double digits, this should be good for a substantial time savings.
However, this optimization has made a test of another cross-import performance optimization fail—not because we have regressed on that, but because it skips work the test case expects us to perform. I have XFAILed that test for now.
Fixes <rdar://problem/59538458>.
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.
VS2015 had an issue with the deletion of an operator. Since VS2017 is
the minimum version that LLVM uses, we can assume that VS2017+ is in use
(_MSC_VER >= 1910). Clean up the now defunct workaround.
Add an alternative to getTopLevelDecls and getDeclChecked to limit which
decls are deserialized by first looking at their attributes. If the
attributes are accepted by a function passed as argument the decl is
fully deserialized, otherwise it is ignored.
The filter is included in the signature of existing functions in the
Serilalization services, but I’ve added new methods for it in FileUnit
and its subclasses to leave existing implementations untouched.
ProtocolConformanceRef already has an invalid state. Drop all of the
uses of Optional<ProtocolConformanceRef> and just use
ProtocolConformanceRef::forInvalid() to represent it. Mechanically
translate all of the callers and callsites to use this new
representation.
Most of AST, Parse, and Sema deal with FileUnits regularly, but SIL
and IRGen certainly don't. Split FileUnit out into its own header to
cut down on recompilation times when something changes.
No functionality change.
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.
We already do this for other ASTContext-allocated types (see
Decl.cpp). This will prevent the sort of mistakes in the previous two
commits.
Note that if any particular subclass of FileUnit wants to have its
destructor run, it can opt into that manually using
ASTContext::addDestructorCleanup. SourceFile and BuiltinUnit both do
this. But we generally don't /want/ to do this if we can avoid it
because it adds to compiler teardown time.
Implementing it in LoadedFile is nice in theory, but causes a leak in
practice because that type is ASTContext-allocated and usually never
destroyed.
https://bugs.swift.org/browse/SR-11366
...rather than the buffer, for a compiled module that came from a
module interface.
This was already happening at a higher level
(ModuleDecl::getModuleFilename) so pushing it down to the low-level
ModuleFile::getModuleFilename doesn't really change things much. The
important fix that goes with this is that SerializedASTFile no longer
leaks this name by storing it outside of ModuleFile.
https://bugs.swift.org/browse/SR-11365
These operations are called frequently, and would get rather
expensive when a ModuleDecl contains a large number of
SourceFiles:
- lookupValue()
- lookupVisibleDecls()
- lookupClassMember()
- lookupClassMembers()
Add fast paths to handle the case where all file units in the
module are SourceFiles, by refactoring SourceFile::LookupCache
from a per-file to a per-module cache.
There was an error when including Module.h in an external project with
std::default_delete being instantiated when making a std::unique_ptr.
This change declares destructor in header file and sets it to default in
cpp file.
Otherwise, there's no guarantee of binary compatibility, and whoever
turned on library evolution support shouldn't be lulled into a false
sense of security.
This is just a warning for now, but will be promoted to an error later
once clients have shaken out any places where they're doing this.
Note that the still-experimental '@_implementationOnly' opts out of
this check, because that enforces that the import doesn't make its way
into the current module's public source or binary interface.
rdar://50261171
