When writing decls to a swiftmodule files, the serialization logic
evaluates whether the decl will be safe to deserialize. This is inferred
from the access level of the decl, whether it's local, if the module is
built for testing, etc. If the decl in unsafe to deserialize, a record
will be written down before the decl itself in the swiftmodule file.
On the reader side, attempting to deserialize a decl marked as unsafe
raises a deserialization error early. This error is handled by the existing
deserialization recovery logic.
In theory, we want to consider as safe only decls that are actually needed by
the client. Marking as many internal details as possible as unsafe will
prevent more errors. Getting the right scope may require more work in
the future.
This change reflects the behavior of `DeclAttribute.printImpl` that
prints the `override` keyword in a swiftinterface only when the
overriden decl is also public.
This issue was detected when working on deserialization safety by public
overrides of private functions in the following tests:
test/Interpreter/vtables_multifile.swift
test/Interpreter/vtables_multifile_testable.swift
test/SILGen/accessibility_vtables_testable.swift
test/SILGen/accessibility_vtables_usableFromInline.swift
test/SILGen/vtables_multifile.swift
Describe attached macros with the `@attached` attribute, providing the
macro role and affected names as arguments to the macro. The form of
this macro will remain the same as it gains other kinds of attached
macro roles beyond "accessor".
Remove the "accessors" role from `@declaration`, which will be going
away.
If the underlying type of an opaque type references an
implementation-only imported type, drop the underlying type information.
Without this fix, once we enable deserialization safety, we see crashes
or dropped decls in more existing tests:
IRGen/mangle-opaque-return-type.swift
IRGen/opaque_result_type_private_underlying.swift
Serialization/Recovery/implementation-only-opaque-type.swift
rdar://103238451
Add support for freestanding declaration macros.
- Parse `@declaration` attribute.
- Type check and expand `MacroExpansionDecl`.
Known issues:
- Generic macros are not yet handled.
- Expansion does not work when the parent decl context is `BraceStmt`. Need to parse freestanding declaration macro expansions in `BraceStmt` as `MacroExpansionDecl`, and add expanded decls to name lookup.
This changes the scanner's behavior to "resolve" a discovered module's dependencies to a set of Module IDs: module name + module kind (swift textual, swift binary, clang, etc.).
The 'ModuleDependencyInfo' objects that are stored in the dependency scanner's cache now carry a set of kind-qualified ModuleIDs for their dependencies, in addition to unqualified imported module names of their dependencies.
Previously, the scanner's internal state would cache a module dependnecy as having its own set of dependencies which were stored as names of imported modules. This led to a design where any time we needed to process the dependency downstream from its discovery (e.g. cycle detection, graph construction), we had to query the ASTContext to resolve this dependency's imports, which shouldn't be necessary. Now, upon discovery, we "resolve" a discovered dependency by executing a lookup for each of its imported module names (this operation happens regardless of this patch) and store a fully-resolved set of dependencies in the dependency module info.
Moreover, looking up a given module dependency by name (via `ASTContext`'s `getModuleDependencies`) would result in iterating over the scanner's module "loaders" and querying each for the module name. The corresponding modules would then check the scanner's cache for a respective discovered module, and if no such module is found the "loader" would search the filesystem.
This meant that in practice, we searched the filesystem on many occasions where we actually had cached the required dependency, as follows:
Suppose we had previously discovered a Clang module "foo" and cached its dependency info.
-> ASTContext.getModuleDependencies("foo")
--> (1) Swift Module "Loader" checks caches for a Swift module "foo" and doesn't find one, so it searches the filesystem for "foo" and fails to find one.
--> (2) Clang Module "Loader" checks caches for a Clang module "foo", finds one and returns it to the client.
This means that we were always searching the filesystem in (1) even if we knew that to be futile.
With this change, queries to `ASTContext`'s `getModuleDependencies` will always check all the caches first, and only delegate to the scanner "loaders" if no cached dependency is found. The loaders are then no longer in the business of checking the cached contents.
To handle cases in the scanner where we must only lookup either a Swift-only module or a Clang-only module, this patch splits 'getModuleDependencies' into an alrady-existing 'getSwiftModuleDependencies' and a newly-added 'getClangModuleDependencies'.
Align the grammar of macro declarations with SE-0382, so that macro
definitions are parsed as an expression. External macro definitions
are referenced via a referenced to the macro `#externalMacro`. Define
that macro in the standard library, and recognize uses of it as the
definition of other macros to use externally-defined macros. For
example, this means that the "stringify" macro used in a lot of
examples is now defined as something like this:
@expression macro stringify<T>(_ value: T) -> (T, String) =
#externalMacro(module: "MyMacros", type: "StringifyMacro")
We still parse the old "A.B" syntax for two reasons. First, it's
helpful to anyone who has existing code using the prior syntax, so they
get a warning + Fix-It to rewrite to the new syntax. Second, we use it
to define builtin macros like `externalMacro` itself, which looks like this:
@expression
public macro externalMacro<T>(module: String, type: String) -> T =
Builtin.ExternalMacro
This uses the same virtual `Builtin` module as other library builtins,
and we can expand it to handle other builtin macro implementations
(such as #line) over time.
Local discriminators for named entities are currently being set by the
parser, so entities not created by the parser (e.g., that come from
synthesized code) don't get local discriminators. Moreover, there is
no checking to ensure that every named local entity gets a local
discriminator, so some entities would incorrectly get a local
discriminator of 0.
Assign local discriminators as part of setting closure discriminators,
in response to a request asking for the local discriminator, so the
parser does not need to track this information, and all local
declarations---including synthesized ones---get local discriminators.
And add checking to make sure that every entity that needs a local
discriminator gets assigned one.
There are a few interesting cases in here:
* There was a potential mangling collision with local property
wrappers because their generated variables weren't getting local
discriminators
* $interpolation variables introduced for string interpolation weren't
getting local discriminators, they were just wrong.
* "Local rename" when dealing with captures like `[x]` was dependent on
the new delcaration of `x` *not* getting a local discriminator. There
are funny cases involving nesting where it would do the wrong thing.
With type-wrappers a custom attribute may reference a type and lead to a
cycle in deserialization if the target type references the type-wrapper.
To avoid this scenario, move deserializing the custom decls from before
to after the decl they are attached to.
rdar://103425758
