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.
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.
My previous change for this issue (033b884de6) did not fix all the
affected code. This gets the rest of them. Thanks for Jason Molenda
for helping with this. rdar://problem/41025365
The signature here changed, but the old arguments implicitly converted
to the parameter types for the wrong overload, so we didn't notice.
Add a simple test that would have at least caught this for the driver.
