Introsuce a new "forward" algorithm for trailing closures where
the unlabeled trailing closure argument matches the next parameter in
the parameter list that can accept an unlabeled trailing closure.
The "can accept an unlabeled trailing closure" criteria looks at the
parameter itself. The parameter accepts an unlabeled trailing closure
if all of the following are true:
* The parameter is not 'inout'
* The adjusted type of the parameter (defined below) is a function type
The adjusted type of the parameter is the parameter's type as
declared, after performing two adjustments:
* If the parameter is an @autoclosure, use the result type of the
parameter's declared (function) type, before performing the second
adjustment.
* Remove all outer "optional" types.
For example, the following function illustrates both adjustments to
determine that the parameter "body" accepts an unlabeled trailing
closure:
func doSomething(body: @autoclosure () -> (((Int) -> String)?))
This is a source-breaking change. However, there is a "fuzzy" matching
rule that that addresses the source break we've observed in practice,
where a defaulted closure parameter precedes a non-defaulted closure
parameter:
func doSomethingElse(
onError: ((Error) -> Void)? = nil,
onCompletion: (Int) -> Void
) { }
doSomethingElse { x in
print(x)
}
With the existing "backward" scan rule, the trailing closure matches
onCompletion, and onError is given the default of "nil". With the
forward scanning rule, the trailing closure matches onError, and there
is no "onCompletion" argument, so the call fails.
The fuzzy matching rule proceeds as follows:
* if the call has a single, unlabeled trailing closure argument, and
* the parameter that would match the unlabeled trailing closure
argument has a default, and
* there are parameters *after* that parameter that require an argument
(i.e., they are not variadic and do not have a default argument)
then the forward scan skips this parameter and considers the next
parameter that could accept the unlabeled trailing closure.
Note that APIs like doSomethingElse(onError:onCompletion:) above
should probably be reworked to put the defaulted parameters at the
end, which works better with the forward scan and with multiple
trailing closures:
func doSomethingElseBetter(
onCompletion: (Int) -> Void,
onError: ((Error) -> Void)? = nil
) { }
doSomethingElseBetter { x in
print(x)
}
doSomethingElseBetter { x in
print(x)
} onError: { error in
throw error
}
Introduce a new frontend flag -enable-volatile-modules to trigger
loading swiftmodule files as volatile and avoid using mmap. Revert the
default behavior to using mmap.
In order to avoid accidentally implicitly loading modules that are expected but were not provided as explicit inputs.
- Use either SerializedModuleLoader or ExplicitSwiftModuleLoader for loading of partial modules, depending on whether we are in Explicit Module Build or Implicit Module Build mode.
Since -emit-module-from-interface now emits forwarding modules, explicit module
loader should be able to accept forwarding modules and unbox their actual binary
contents.
-compile-module-from-interface action now takes arguments of -candidate-module-file.
If one of the candidate module files is up-to-date, the action emits a forwarding
module pointing to the candidate module instead of building a binary module.
Instead of replacing an interface file with its up-to-date compile module,
the dep-scanner should report potentially up-to-date module candidates either adjacent to
the interface file or in the prebuilt module cache. swift-driver should later pass down
these candidates to -compile-module-from-interface invocation and the front-end job
will check if one of the candidates is ready to use. The front-end job then either emits a forwarding
module to an up-to-date candidate or a binary module.
This flag no longer does anything now that the unified statistics
reporting infrastructure exists. It is better to use
-driver-time-compilation to see a bird's eye view of timing statistics
for frontend jobs, and -stats-output-dir to see a down-and-dirty view of
everything including performance counters.
To support multiple versions of SDKs of the same platform, we should move prebuilt
module cache into an SDK-versioned sub-directory and teach the compiler to look into
the directory if present.
rdar://65488510
The situations where we use this action, e.g. explicit module building and
generating prebuilt module cache, don't need synchronization. We should avoid
using lock files for them.
rdar://65005528
Its use in deserialization can be replaced with a
more general check for whether we're deserializing
into the same module. Its use in the SILVerifier
is subsumed by the check for whether the SILModule
is canonical, which it isn't during merge-modules.
Previously we would only link `.sib` partial
modules in SILGen, with other kinds of serialized
ASTs being linked just before the SILOptimizer if
`-sil-merge-partial-modules` was specified.
However linking them always seems to be the desired
behaviour, so adjust SILGen to link SIL for all
serialized AST inputs.
This commit adds -lto flag for frontend to enable LTO at LLVM level.
When -lto=llvm given, compiler emits LLVM bitcode file instead of object
file and adds index summary for LTO.
In addition for ELF format, emit llvm.dependent-libraries section to
embed auto linking information
For the explicit module mode, swift-driver uses -compile-module-from-interface to
generate modules from interfaces found by the dependency scanner. However, we don't
need to build the binary module if up-to-date modules are available, either adjacent
to the interface file or in the prebuilt module cache directory. This patch teaches
dependencies scanner to report these ready-to-use binary modules.
Expand the FrontendOptions to allow the enabling
of the dependency tracker for non-system
dependencies, and switch the previous clients of
`createDependencyTracker` over to using this
option. This ensures that the dependency tracker
is now set only during `CompilerInstance::setup`.
This makes it easier to specify OptionSet arguments.
Also modify appropriate uses of ModuleDecl::ImportFilter to take
advantage of the new constructor.
We will eventually move the protocol entirely to using a JSON file for
explicit Swift modules. Before we finish migrating, we should be forgiving
about using the legacy -swift-module-file argument.
Previously we may have silently bailed if a private
module interface path was specified, but the
frontend action didn't support it. Instead, make
sure we enforce the same restrictions that we
enforce for public module interfaces.
Instead of taking paths of Swift module files from front-end command line
arguments, we should take a JSON file specifying details of explicit modules.
The advantages is (1) .swiftdoc and .swiftsourceinfo can be associated
with a .swiftmodule file, and (2) module names are explicitly used as
keys in the JSON input so we don't need to eagerly deserialize a .swiftmodule
file to collect the module name.
