This replaces the use of a Clang utility function that was
inexplicably a non-static member function of CompilerInstance. It
would be nice to sink this all the way to LLVM and share the
implementation across both projects, but the Clang implementation does
a handful of things we don't need, and it's hard to justify including
them in an LLVM-level interface. (I stared at
llvm/Support/FileSystem.h for a long time before giving up.)
Anyway, Serialization and FrontendTool both get their atomic writes
now without depending on Clang, and without duplicating the
scaffolding around the Clang API. We should probably adopt this for
all our output files.
No functionality change.
Continuing work from #18344, be more conservative about when we load
SwiftOnoneSupport. Specifically, -emit-silgen and -emit-sibgen, despite
not going through the SIL Optimizer, may silently introduce dependencies
on SwiftOnoneSupport.
Because we want to support the ability to posthumously compile SILGen
and SIBGen'd files with these implicit dependencies, and because SIL
is not yet capable of expressing the dependency itself, we must always
assume we need to load SwiftOnoneSupport.
Adds the -vfsoverlay frontend option that enables the user to pass
VFS overlay YAML files to Swift. These files define a (potentially
many-layered) virtual mapping on which we predicate a VFS.
Switch all input-based memory buffer reads in the Frontend to the new
FileSystem-based approach.
Introduces the -name-bind frontend action that is intended as an intermediary between the parse-only actions and a full typechecking pass. In this phase, module imports will be validated and resolved, making it possible to emit full make-style dependencies files among other things.
Note that all information available to a parse-only pass is available to name binding, but because it does not continue-on to typecheck input files, full semantic information is not.
More groundwork for protocols with superclass constraints.
In several places we need to distinguish between existential
types that have a superclass term (MyClass & Proto) and
existential types containing a protocol with a superclass
constraint.
This is similar to how I can write 'AnyObject & Proto', or
write 'Proto1 & Proto2' where Proto1 has an ': AnyObject'
in its inheritance clause.
Note that some of the usages will be revisited later as
I do more refactoring and testing. This is just a first pass.
TBD validation is effectively an expensive assertion, and is currently only
tuned for Apple platforms. However, we don't want it to regress more, and it
would be nice to start getting validation from people using master
snapshots. Together, this means that turning it on by default for the cases
mentioned above is an appropriate course of action.
At the very least, this has the benefit of running validation across the stdlib,
the overlays and the whole testsuite on each build, so people making changes to
the compiler that change symbols are hopefully alerted.
One limitation here is that this is only validating that the TBD is a superset
of the true set of symbols: it could include spurious symbols that aren't
actually in the binary. This case is less problematic for Swift than symbols
missing from the TBD file, and so we've focused energy on this. Once we've fixed
the extra-symbols problems and are confident in it, this validation can be
upgraded to validate that too.
Half of rdar://problem/40431434.
Introduce a command-line option to visualize the complete set of output
request dependencies evaluated by a particular compile action. This is
exposing existing visualization facilities to the (-frontend) command line.
