- Instead of keeping multiple flags in the type descriptor flags,
just keep a single flag indicating the presence of additional
import information after the name.
- That import information consists of a sequence of null-terminated
C strings, terminated by an empty string (i.e. by a double null
terminator), each prefixed with a character describing its purpose.
- In addition to the symbol namespace and related entity name,
include the ABI name if it differs from the user-facing name of the
type, and make the name the user-facing Swift name.
There's a remaining issue here that isn't great: we don't correctly
represent the parent relationship between error types and their codes,
and instead we just use the Clang module as the parent. But I'll
leave that for a later commit.
Rather than storing a mangled name in a Swift protocol descriptor,
which encodes information that is redundant with the context of the
protocol, store an unmangled name as in nominal type descriptors. Update
the various places where this name is used to extract the demangle
tree from the context descriptors.
Reimplement protocol descriptors for Swift protocols as a kind of
context descriptor, dropping the Objective-C protocol compatibility
layout. The new protocol descriptors have several advantages over the
current implementation:
* They drop all of the unused fields required for layout-compatibility
with Objective-C protocols.
* They encode the full requirement signature of the protocol. This
maintains more information about the protocol itself, including
(e.g.) correctly encoding superclass requirements.
* They fit within the general scheme of context descriptors, rather than
being their own thing, which allows us to share more code with
nominal type descriptors.
* They only use relative pointers, so they’re smaller and can be placed
in read-only memory
Implements rdar://problem/38815359.
Switch one entry point in the runtime (swift_getExistentialTypeMetadata)
to use ProtocolDescriptorRef rather than a protocol descriptor. Update
IRGen to produce ProtocolDescriptorRef instances for its calls, setting
the discriminator bit appropriately.
Within the runtime, verify that all instances of ProtocolDescriptorRef have
the right layout, i.e., the discriminator bit is set for @objc protocols
but not Swift protocols.
Clang-importer-synthesized declarations get an extra tag character included in their mangling, which was not being preserved in type context descriptors. This caused runtime lookup for these synthesized types to fail. Fix this by adding the tag information to type context descriptors and teaching the runtime to match it up when fetching metadata by mangled name. Fixes rdar://problem/40878715.
This provides a slight amount of defense against attackers constructing mangled names with offsets crafted to JOP the runtime into attacker-controlled code. (Someone could still find some random code or constant data artifact in a binary that *looks* like a mangled string with symbolic references and theoretically attack that way, but they at least wouldn't be able to construct their own string entirely.)
LLVM r334283 changed StringRef::split(char) to be implemented using
StringRef::split(StringRef), which is not defined inline. Because Swift
uses StringRef without linking LLVM's libSupport.a, we can only use
functions that are defined inline in the headers. Swift currently only
builds LLVM for the host, so we cannot link libSupport.a without building
it for every target, which would be a big change. Instead, this changes
a few places in Swift to avoid using those split and rsplit functions.
rdar://problem/41029268
Support demangling for types nested within some simple extension contexts.
Still does not support nested types within constrained extensions that
involve same-type constraints among generic parameters, nor
deeply-nested types in extensions. However, it fixes
rdar://problem/40071688.
Previously we could only handle symbolic references at the
top level, but this is insufficient; for example, you can
have a nested type X.Y where X is defined in the current
translation unit and Y is defined in an extension of X in
a different translation unit. In this case, X.Y mangles as
a tree where the child contains a symbolic reference to X.
Handle this by adding a new form of Demangle::mangleNode()
which takes a callback for resolving symbolic references.
Fixes <rdar://problem/39613190>.
The demangling tree for a symbolic reference doesn't indicate the generic context depth of the referenced type, so we have to form the type metadata from whole cloth without incrementally building up nested types as we do for concrete mangled types. Notice when DecodedMetadataBuilder is passed a context descriptor ref without a parent and directly form the entire type in this case. Fixes rdar://problem/38891999.
I was going to put this off for awhile, but it turns out that a lot of
my testcases are enums with multi-payload cases, which we currently
compile as tuples, so they were all still hanging until this patch.
I de-templated MetadataState and MetadataRequest because we weren't
relying on the template and because using the template was causing
conversion problems due to the inability to directly template an enum
in C++.
This includes global generic and non-generic global access
functions, protocol associated type access functions,
swift_getGenericMetadata, and generic type completion functions.
The main part of this change is that the functions now need to take
a MetadataRequest and return a MetadataResponse, which is capable
of expressing that the request can fail. The state of the returned
metadata is reported as an second, independent return value; this
allows the caller to easily check the possibility of failure without
having to mask it out from the returned metadata pointer, as well
as allowing it to be easily ignored.
Also, change metadata access functions to use swiftcc to ensure that
this return value is indeed returned in two separate registers.
Also, change protocol associated conformance access functions to use
swiftcc. This isn't really related, but for some reason it snuck in.
Since it's clearly the right thing to do, and since I really didn't
want to retroactively tease that back out from all the rest of the
test changes, I've left it in.
Also, change generic metadata access functions to either pass all
the generic arguments directly or pass them all indirectly. I don't
know how we ended up with the hybrid approach. I needed to change all
the code-generation and calls here anyway in order to pass the request
parameter, and I figured I might as well change the ABI to something
sensible.
All of the information contained by this field (list of property names)
is already encoded as part of the field reflection metadata and
is accessible via `swift_getFieldAt` runtime method.
Use information from reflection section of the binary to lookup
type field info such as name and it's type and return it using
new `swift_getFieldAt` method based on nominal type and field index.
