We sometimes see expression type checking times increase dramatically
when this is enabled, and having a way to disable will make it
possible to easily do measurements to determine the cost/benefit of
having this enabled.
As a debugging aid, introduce a new frontend flag `-debug-cycles` that
will emit a debug dump whenever the request-evaluator encounters a cyclic
dependency, while otherwise allowing compilation to continue.
This work-around is no longer needed now that the full fix landed in
https://github.com/apple/swift/pull/16615. The argument is left with a warning
to help with migration between compilers with the work-around and compilers with
the full fix (see also rdar://problem/40502379).
Fixes rdar://problem/40476573.
IRGen can introduce calls to type metadata accessors for types that
should not be visible to the current translate, which can manifest in
linker errors within a module (for references to private types when
whole module optimization is disabled) or across modules (for
references to private/internal types in another module). Introduce a
new compiler flag `-emit-public-type-metadata-accessors` that emits
all type metadata accessors with public linkage, to work around the
problem in affected projects. This flag is intended to go away once we
have a proper solution.
This bug has been around in Swift "forever", but compiling the
overlays using -enable-resilience has exacerbated the problem and
caused regressions. This is a short-term fix to
rdar://problem/40229755 while we work on the correct long-term fix.
Note that I said "warnings"; we're going to be more cautious about
rollout and just make this a warning in Swift 5 mode, with /no/
diagnostics in Swift 3 and 4. Users are still free to use `@unknown
default` in these modes, and they'll get a fatal run-time error if
they don't and an unexpected case actually shows up.
rdar://problem/29324688
When running Swift from within LLDB, we need to bypass resilience since LLDB
does not support resilience yet. However, the bypass was done too early as
part of the module loader, which had the effect of disabling resilience
altogether.
We still want resilience at the SIL level so that function types lower the
same with debugger support turned on and off. Only IRGen needs to bypass
resilience, so that LLDB can calculate fragile layouts of types. Also, the
DebuggerSupport flag is not always set in the ASTContexts created by LLDB.
So replace it with a new flag that only controls this behavior and nothing
else, and make it part of IRGenOptions to make it totally clear that it only
impacts IRGen.
Together with the paired LLDB change, fixes <rdar://problem/38719739>
and <rdar://problem/38483762>.
It was only used in a few tests. Those tests now use -emit-sil instead
of -emit-silgen, with some functions marked @_transparent and a few
CHECK: lines changed now that the mandatory optimizations get to run.
Continue to emit notes for the candidates, but use different text.
Note that we can emit a typo correction fix-it even if there are
multiple candidates with the same name.
Also, disable typo correction in the migrator, since the operation
is quite expensive, the notes are never presented to the user, and
the fix-its can interfere with the migrator's own edits.
Our general guidance is that fix-its should be added on the main
diagnostic only when the fix-it is highly likely to be correct.
The exact threshold is debateable. Typo correction is certainly
capable of making mistakes, but most of its edits are right, and
when it's wrong it's usually obviously wrong. On balance, I think
this is the right thing to do. For what it's worth, it's also
what we do in Clang.
To support migration from both Swift 3 and 4, this patch
teaches the driver to pick up the right set of migration scripts
according to the given Swift version. We also pushed some placeholder script
files for migration from Swift 4. This patch also brings the migrator
up-to-date by avoiding migration if the Swift version is already 4.2.
This may help us reproduce a failing build when all we have is a build
log, and will become much more important in batch mode when we
/really/ need to know what ended up in what batch.
For now, this doesn't include /output/ filelists, because David's
about to mess with that code anyway to make things better around
supplementary outputs in batch mode. There is one weirdness there,
though, which is that ArgsToFrontendInputsConverter peeks at the
outputs to see whether we're doing single-threaded or multi-threaded
WMO.
This means moving the output path into SupplementaryOutputPaths, and
using the same sort of diagnostic dispatching that serialized
diagnostics use. This is part of what's needed to run the migrator
in batch mode.
This way we'll link against the key path component the other module provides instead of making fragile assumptions about its current implementation. Since external keypath lowering isn't fully implemented elsewhere in the compiler, this is enabled behind a staging flag.
external keypath staging
The current implementation isn't really useful in the face of generic
overloads. It has never been enabled by default, and isn't useful to
keep around if it is disabled. If we ever want to bring it back,
we know where to look!
Swift class metadata has a bit to distinguish it from non-Swift Objective-C
classes. The stable ABI will use a different bit so that stable Swift and
pre-stable Swift can be distinguished from each other.
No bits are actually changed yet. Enabling the new bit needs to wait for
other coordination such as libobjc.
rdar://35767811
The original hope was we could make these heuristics really good, but
since that is not currently in sight (and may never be), we want to be
able to turn them off. For now, just plumb through an internal flag to
control the behaviour. A future change will customize the behaviour in
SourceKit.
rdar://31113161
- Outlaw duplicate input files, fix driver, fix tests, and add test.
- Reflect that no buffer is present without a (possibly pseudo) named file.
- Reflect fact that every input has a (possible pseudo) name.
- Break up CompilerInstance::setup.
-
