This adds tracking of the vtable holes due to a failure to deserialize
vtable entries. This allows for the user to be able to identify what
member failed to be deserialied and can aid in understanding why an
`open` class may not be subclassed.
Future improvements here would allow tracing the XRefPath which failed
to be deserialied. However, this still provides an improvement over the
existing experience where there is no available information on why the
class cannot be inherited from.
A type dependencies are used at deserialization to drop a protocol early
when a dependency is not deserializable. Dependencies on protocols via a
protocol composition were not taken into account. This lead to the
deserialization process failing later. Fix the serialization process to
write protocol dependencies too.
rdar://78631465
Access to a missing member on an AnyObject triggers a typo correction
that looks at all class members in imported modules. Make sure it
recovers from deserializing members referencing implementation-only
imported types.
rdar://79427805
Rather than outputting diagnostics and to stderr, output all the extra
information added when deserialization fatally fails to the pretty stack
trace instead. Since the pretty stack trace is added to crash logs, this
should avoid the dance of requesting the compiler output
- Moves the previous "**** DESERIALIZATION FAILURE ..." output to the
last pretty stack trace line
- Removes the module and compiler version notes added to the fatal
diagnostic
- Adds a new effective compiler version line for all frontend failure.
Somewhat duplicates the line from the driver, but adds in the
effective version
- Adds a new line for the full misc version of the module that failed.
May double up with previous "While reading from ..." lines that are
added in various deserialization methods, but better to have it
twice than not at all
In the added test case, the `typealias` refers to the `HiddenStruct` type in the private module, which is imported as `@_implementationOnly`. Because the import is `@_implementationOnly`, during deserialization, we don’t import the private module and hence any reference to the `HiddenStruct` type fails. In the common deserialization code path, this causes us to skip over the `typealias` member. However, when creating the protocol conformance, we assume that we can resolve the type to which the `typealias` refers and thus we are crashing.
If `LangOpts.EnableDeserializationRecovery` is set to `true`, we should do our best to recover from such failures so this patch makes the deserialization failure handling more graceful and resolve the right-hand side of the `typealias` as an `ErrorType`.
Fixes rdar://72891807
While the comment is correct to state that this won't enable any
new optimizations with -Onone, it does enable IRGen's lazy
function emission, which is important for 'reasync' functions,
which we don't want to emit at all even at -Onone.
This fixes debug stdlib builds with the new reasync versions
of the &&, || and ?? operators.
Implementation-only imports are unnecessary in generated module interfaces, since they aren't exported to the module's dependencies, and the module's public API cannot refer to symbols imported as implementation-only.
The new message is:
"Please submit a bug report (https://swift.org/contributing/#reporting-bugs) and include the crash backtrace."
1. In crash logs we used to print a message which points to the llvm bug tracking page. Now it points to the swift.org bug tracking guidelines.
2. Use the same message in all compiler diagnostics which ask the user to file a bug report.
rdar://problem/70488534
In #30614, we started consuming XRefNonLoadedModuleErrors while loading
conformances, since a conformance to a type we cannot load usually
indicates we're trying to load a protocol that was declared in an
@_implementationOnly imported module.
We should also consume TypeErrors that we see where the underlying reason
is an XRefNonLoadedModuleError, since they're likely indicators of the
same thing.
We already ban all structs from declaring storage that comes from implementation-only imports. Until now we missed property wrappers, they were just dropped in deserialization.
Resolves rdar://problem/59403617
Components of a requirement may be hidden behind an implementation-only
import. Attempts at deserializing them would fail on a 'module not
loaded' error. We only see failures in non-compilation paths, either in
indexing or with tools like ide-test as they try to deserialize
things that are private.
* [TypeChecker] Enclosing stubs protocol note within editor mode
* [test] Removing note from test where there is no -diagnostics-editor-mode flag
* Formatting modified code
* [tests] Fixing tests under validation-tests
In some circumstances, a Swift declaration in module A will depend on
another declaration (usually from Objective-C) that can't be loaded,
for whatever reason. If the Swift declaration is *overriding* the
missing declaration, this can present a problem, because the way
methods are dispatched in Swift can depend on knowing the original
class that introduced the method. However, if the compiler can prove
that the override can still be safely invoked/used in all cases, it
doesn't need to worry about the overridden declaration being missing.
This is especially relevant for property accessors, because there's
currently no logic to recover from a property being successfully
deserialized and then finding out that an accessor couldn't be.
The decision of whether or not an override can be safely invoked
without knowledge of the base method is something to be cautious
about---a mistaken analysis would effectively be a miscompile. So up
until now, this was limited to one case: when a method is known to be
`@objc dynamic`, i.e. always dispatched through objc_msgSend. (Even
this may become questionable if we have first-class method references,
like we do for key paths.) This worked particularly well because the
compiler infers 'dynamic' for any overload of an imported Objective-C
method or accessor, in case it imports differently in a different
-swift-version and a client ends up subclassing it.
However...that inference does not apply if the class is final, because
then there are no subclasses to worry about.
This commit changes the test to be more careful: if the /missing/
declaration was `@objc dynamic`, we know that it can't affect ABI,
because either the override is properly `@objc dynamic` as well, or
the override has introduced its own calling ABI (in practice, a direct
call for final methods) that doesn't depend on the superclass. Again,
this isn't 100% correct in the presence of first-class methods, but it
does fix the issue in practice where a property accessor in a parent
class goes missing. And since Objective-C allows adding property
setters separately from the original property declaration, that's
something that can happen even under normal circumstances. Sadly.
This approach could probably be extended to constructors as well. I'm
a little more cautious about throwing vars and subscripts into the mix
because of the presence of key paths, which do allow identity-based
comparison of overrides and bases.
rdar://problem/56388950
Harden more of the serialization functions to propagate errors for
the caller to handle these errors gracefully. This fixes a crash in
finishNormalConformance when indexing a system module with an
implementation-only import.
rdar://problem/52837313
Accessors logically belong to their storage and can be synthesized
on the fly, so removing them from the members list eliminates one
source of mutability (but doesn't eliminate it; there are also
witnesses for derived conformances, and implicit constructors).
Since a few ASTWalker implementations break in non-trivial ways when
the traversal is changed to visit accessors as children of the storage
rather than peers, I hacked up the ASTWalker to optionally preserve
the old traversal order for now. This is ugly and needs to be cleaned up,
but I want to avoid breaking _too_ much with this commit.
Once accessors are no longer listed as members of their parent context,
a failure to deserialize a VarDecl or SubscriptDecl needs to create a
MissingMemberDecl with the total number of vtable entries expected for
all of the accessors of the storage.
Note that until the accessor change actually lands, we always compute
the expected number of vtable entries as 0.
Under non-editor mode, the fixit for inserting protocol stubs is associated with a note
pointing to the missing protocol member declaration which could stay in a separate file from
the conforming type, leading to the behavior of rdar://51534405. This change checks if
the fixit is in a separate file and issues another note to carry the fixit if so.
rdar://51534405
If a protocol inherits from a protocol that can't be loaded, drop it
entirely. Similarly, if it has requirements that reference types in
other modules that can't be loaded, drop the protocol entirely---at
least for now, we don't want to deal with a protocol that exists but
has the wrong requirement signature. That "in other modules" isn't
perfect, but it avoids cases where two protocols depend on each other.
Unfortunately, it means the compiler may still get into exactly the
situation above if a protocol depends on another protocol in the same
module, and /that/ protocol can't be loaded for some other reason. But
it's progress.
This comes up when referencing implementation-only-imported protocols
from non-public protocols, but is also just general deserialization
recovery goodness.
rdar://problem/52141347
...specifically `@objc dynamic`, that is. This is one case where we
/know/ that the override does not depend on the base in any way---any
attributes have already been propagated down, and there's no vtable
entry. This is especially important for properties, which have no
recovery if their accessors can't be deserialized.
rdar://50827914
