Include the initial implementation of _StringGuts, a 2-word
replacement for _LegacyStringCore. 64-bit Darwin supported, 32-bit and
Linux support in subsequent commits.
Following up on the fixes for rdar://problem/35330067. If a class inherits a class from another module with missing fields, we need to treat its size and alignment as opaque, just like the base class itself. We also need to lay out such class at runtime, since we don't know the size, alignment, or field offsets at compile time; relying on the ObjC runtime alone will slide the ivar offsets, but not the Swift instance size and alignment. Fixes rdar://problem/35747485.
We would miscompile in mixed-language-version projects when a Swift class was compiled for one language version, while using Objective-C-imported types that are only available to that version, and then imported into a Swift module with a different language version that wasn't able to see all of the properties because of incompatible imported types. This manifested in a number of ways:
- We assumed we could re-derive the constant field offsets of the class's ivars from the layout, which is wrong if properties are missing, causing accesses to final properties or subclass properties to go to the wrong offsets.
- We assumed we could re-derive the instance size and alignment of a class instance in total, causing code to allocate the wrong amount of memory.
- We neglected to account for the space that stored properties take up in the field offset vector of the class object, causing us to load vtable entries for following subclass methods from the wrong offsets.
Eventually, resilience should reduce our exposure to these kinds of problems. As an incremental step in the right direction, when we look at a class from another module in IRGen, treat it as always variably-sized, so we don't try to hardcode offsets, size, or alignment of its instances. When we import a class, and we're unable to import a stored property, leave behind a new kind of MissingMemberDecl that records the number of field offset vector slots it will take up, so that we lay out subclass objects and compute vtable offsets correctly. Fixes rdar://problem/35330067.
A side effect of this is that the RemoteAST library is no longer able to provide fixed field offsets for class ivars. This doesn't appear to impact the lldb test suite, and they will ultimately need to use more abstract access patterns to get ivar offsets from resilient classes (if they aren't already), so I just removed the RemoteAST test cases that tested for class field offsets for now.
Partially reverts f4f8349 (from July!) which caused us to start
importing global blocks with unbridged parameters, breaking source
compatibility. I'm still investigating whether there's an actual hole
in the logic; see next few commits.
rdar://problem/34913634
Use the modern spelling for the nullability attributes in the test mock
headers. Currently, this was relying on the predefined macros from
clang to work. However, those are only available on Darwin targets.
This is needed to make the mock environments more portable.
Logs a warning the first time a problematic class is archived or
unarchived. We expect people to actually fix these issues, so the
performance of the warning isn't too important.
Sample output:
[timestamp] Attempting to archive Swift class '_Test.Outer.ArchivedThenUnarchived', which does not have a stable runtime name.
[timestamp] Use the 'objc' attribute to ensure that the runtime name will not change: "@objc(_TtCC5_Test5Outer22ArchivedThenUnarchived)"
[timestamp] If there are no existing archives containing this class, you can choose a unique, prefixed name instead: "@objc(ABCArchivedThenUnarchived)"
Finishes rdar://problem/32414508
This function checks if a mangled class name is going to be written into an NSArchive.
If yes, a warning should be printed and the return value should indicate that.
TODO: print the actual warning
rdar://problem/32414508
This time, the warnings only fire when the class in question directly
conforms to NSCoding. This avoids warning on cases where the user has
subclassed something like, oh, UIViewController, and has no intention
of writing it to a persistent file.
This also removes the warning for generic classes that conform to
NSCoding, for simplicity's sake. That means
'@NSKeyedArchiverEncodeNonGenericSubclassesOnly' is also being
removed.
Actually archiving a class with an unstable mangled name is still
considered problematic, but the compiler shouldn't emit diagnostics
unless it can be sure they are relevant.
rdar://problem/32314195
This is accomplished by recognizing this specific situation and
replacing the 'objc' attribute with a hidden '_objcRuntimeName'
attribute. This /only/ applies to classes that are themselves
non-generic (including any enclosing generic context) but that have
generic ancestry, and thus cannot be exposed directly to Objective-C.
This commit also eliminates '@NSKeyedArchiverClassName'. It was
decided that the distinction between '@NSKeyedArchiverClassName' and
'@objc' was too subtle to be worth explaining to developers, and that
any case where you'd use '@NSKeyedArchiverClassName' was already a
place where the ObjC name wasn't visible at compile time.
This commit does not update diagnostics to reflect this change; we're
going to change them anyway.
rdar://problem/32414557
Only emit calls to Builtin.swift3ImplicitObjCEntrypoint() when we are
in Swift 4 mode with `-enable-swift3-objc-inference`, which is a
transitional state in which one is debugging the use of the
deprecated @objc entrypoints. Fixes rdar://problem/32122408.
Like NSObject, CFType has primitive operations CFEqual and CFHash,
so Swift should allow those types to show up in Hashable positions
(like dictionaries). The most general way to do this was to
introduce a new protocol, _CFObject, and then have the importer
automatically make all CF types conform to it.
This did require one additional change: the == implementation that
calls through to CFEqual is in a new CoreFoundation overlay, but the
conformance is in the underlying Clang module. Therefore, operator
lookup for conformances has been changed to look in the overlay for
an imported declaration (if there is one).
This re-applies 361ab62454, reverted in
f50b1e73dc, after a /very/ long interval
where we decided if it was worth breaking people who've added these
conformances on their own. Since the workaround isn't too difficult---
use `#if swift(>=3.2)` to guard the extension introducing the
conformance---it was deemed acceptable.
https://bugs.swift.org/browse/SR-2388
Register class names for NSKeyedArchiver and NSKeyedUnarchiver based on the @NSKeyedArchiveLegacy and @_staticInitializeObjCMetadata class attributes.
@NSKeyedArchiveLegacy registers a class name translation.
@_staticInitializeObjCMetadata just makes sure that the metadata of a class is instantiated.
This registration code is executed as a static initializer, like a C++ global constructor.
Introduce the @NSKeyedArchiveSubclassesOnly attribute, which can be
placed on a class that conforms to NSCoding to suppress the
unstable-name diagnostics by promising to only archive
subclasses---not this class directly.
This attribute allows one to provide the "legacy" name of a class for
the purposes of archival (via NSCoding). At the moment, it is only
useful for suppressing the warnings/errors about classes with unstable
archiving names.
The name mangling changed from Swift 3 to Swift 4, and may get slight
tweaks as we lock down ABI stability. Identify and warn about (in
Swift 3) or error about (in Swift 4) the cases where we don't have
obviously-stable name mangling, e.g.,
* private/fileprivate classes (whose mangled names involve the file name)
* nested classes (whose mangled names depend on their enclosing type)
* generic classes (whose mangled names involve the type arguments)
This only affects the textual output, but should still improve the
experience when we /do/ hit one of these LLVM errors. In addition to
showing up better in Xcode, it'll also give us a proper
PrettyStackTrace because of the call to abort() instead of exit(1).
(There's a bit of finger-crossing that the act of printing the
diagnostic doesn't cause more errors. I only tested the fallback
path a little.)
