This key is used for deduping data, so this is needed to avoid coalescing the info from two types that are have identical info except for this flag.
rdar://177075642
To summarize the theory based on
`validation-test/Evolution/test_protocol_add_reparented.swift`:
1. Two extensions on MultiParent share the mangled name
$s23protocol_add_reparented11MultiParentPAAEMXE for their context descriptor
2. The first extension to be emitted creates a GlobalVariable with type
TypeContextDescriptorTy (forward decl)
3. The second extension finds it in getAddrOfSharedContextDescriptor via
Module.getGlobalVariable() and inserts the same pointer in GlobalVars
4. When the first extension's descriptor gets defined, getAddrOfLLVMVariable
creates a new GlobalVariable and erases the old one.
5. The second extension's GlobalVars entry is now a dangling pointer, as the
act of defining it for the first extension definition didn't update the map.
This patch does seem to fix the dangling pointer, though there is probably
a better way to fix the underlying bad ordering of events.
When building the `OSLog` module, look for a variable named
`osLogStringSectionName`. It must have a string literal as its
initializer, which provides the section name where the log strings
should be emitted. The `OSLog` module should contain something like
this:
let osLogStringSectionName = "__TEXT,__logit"
When not present, the compiler will default to
`__TEXT,__oslogstring,cstring_literals`, which was previously the
hardcoded section name. Now, OSLog can customize the name.
Implements rdar://171571056
rdar://158239258
This change adds logic in the compiler to compute malloc type ids and emit them together with typed allocation calls. It also adds the new runtime function swift_allocObjectTyped, which calls typed malloc.
Add flag `-debug-module-cache-key` and flag `-debug-module-self-key` to
support embedded swift module output in the debug info via CASID.
rdar://169110002
We cannot use 'static' linkage for something that points into the
ASTContext, because there might be more than one ASTContext in a
single process.
Also, fix the spelling mistake in a related function name.
MCCAS wasn't setup correctly when using parallel WMO. Make sure the
CAS ObjectStore and ResultCallbacks are passed to LLVM backend when
using parallel WMO.
rdar://164409895
This is currently disabled by default. Building the client library can be enabled with the CMake option SWIFT_BUILD_CLIENT_RETAIN_RELEASE, and using the library can be enabled with the flags -Xfrontend -enable-client-retain-release.
To improve retain/release performance, we build a static library containing optimized implementations of the fast paths of swift_retain, swift_release, and the corresponding bridgeObject functions. This avoids going through a stub to make a cross-library call.
IRGen gains awareness of these new functions and emits calls to them when the functionality is enabled and the target supports them. Two options are added to force use of them on or off: -enable-client-retain-release and -disable-client-retain-release. When enabled, the compiler auto-links the static library containing the implementations.
The new calls also use LLVM's preserve_most calling convention. Since retain/release doesn't need a large number of scratch registers, this is mostly harmless for the implementation, while allowing callers to improve code size and performance by spilling fewer registers around refcounting calls. (Experiments with an even more aggressive calling convention preserving x2 and up showed an insignificant savings in code size, so preserve_most seems to be a good middle ground.)
Since the implementations are embedded into client binaries, any change in the runtime's refcounting implementation needs to stay compatible with this new fast path implementation. This is ensured by having the implementation use a runtime-provided mask to check whether it can proceed into its fast path. The mask is provided as the address of the absolute symbol _swift_retainRelease_slowpath_mask_v1. If that mask ANDed with the object's current refcount field is non-zero, then we take the slow path. A future runtime that changes the refcounting implementation can adjust this mask to match, or set the mask to all 1s to disable the old embedded fast path entirely (as long as the new representation never uses 0 as a valid refcount field value).
As part of this work, the overall approach for bridgeObjectRetain is changed slightly. Previously, it would mask off the spare bits from the native pointer and then call through to swift_retain. This either lost the spare bits in the return value (when tail calling swift_retain) which is problematic since it's supposed to return its parameter, or it required pushing a stack frame which is inefficient. Now, swift_retain takes on the responsibility of masking off spare bits from the parameter and preserving them in the return value. This is a trivial addition to the fast path (just a quick mask and an extra register for saving the original value) and makes bridgeObjectRetain quite a bit more efficient when implemented correctly to return the exact value it was passed.
The runtime's implementations of swift_retain/release are now also marked as preserve_most so that they can be tail called from the client library. preserve_most is compatible with callers expecting the standard calling convention so this doesn't break any existing clients. Some ugly tricks were needed to prevent the compiler from creating unnecessary stack frames with the new calling convention. Avert your eyes.
To allow back deployment, the runtime now has aliases for these functions called swift_retain_preservemost and swift_release_preservemost. The client library brings weak definitions of these functions that save the extra registers and call through to swift_retain/release. This allows them to work correctly on older runtimes, with a small performance penalty, while still running at full speed on runtimes that have the new preservemost symbols.
Although this is only supported on Darwin at the moment, it shouldn't be too much work to adapt it to other ARM64 targets. We need to ensure the assembly plays nice with the other platforms' assemblers, and make sure the implementation is correct for the non-ObjC-interop case.
rdar://122595871
This is currently not wired up to anything. I am going to wire it up in
subsequent commits.
The reason why we are introducing this new Builtin type is to represent that we
are going to start stealing bits from the protocol witness table pointer of the
Optional<any Actor> that this type is bitwise compatible with. The type will
ensure that this value is only used in places where we know that it will be
properly masked out giving us certainty that this value will not be used in any
manner without it first being bit cleared and transformed back to Optional<any
Actor>.
Lazy emission of SIL global variables caused us to go through the
creation of two different LLVM struct types for the same
initialization, tripping an assertion in LLVM. Cache it along with
other information about the static-initialized object rather than
rebuilding it.
Also fix the lazy_globals test to account for the laziness,
generalizing it to also run on arm64 so I won't miss it locally.
Delay the emission of SIL global variables that aren't externally
visible until they are actually used. This is the same lazy emission
approach that we use for a number of other entities, such as SIL
functions.
Part of rdar://158363967.
functions to compute them directly without a TypeLowering object, and
change a lot of getTypeLowering call sites to just use that.
There is one subtle change here that I think is okay: SILBuilder used to
use different TypeExpansionContexts when inserting into a global:
- getTypeLowering() always used a minimal context when inserting into
a global
- getTypeExpansionContext() always returned a maximal context for the
module scope
The latter seems more correct, as AFAIK global initializers are never
inlinable. If they are, we probably need to configure the builder with
an actual context properly rather than making global assumptions.
This is incremental progress towards computing this for most types
without a TypeLowering, and hopefully eventually removing TL entirely.
Calling setupLLVMOptimizationRemarks overwrites the MainRemarkStreamer
in the LLVM context. This prevents LLVM from serializing the remark meta
information for the already emitted SIL remarks into the object file.
Without the meta information bitstream remarks don't work correctly.
Instead, emit SIL remarks and LLVM remarks to the same RemarkSerializer,
and keep the file stream alive until after CodeGen.
Expose the createStructType helper to clients of IRGenModule which want
to define types which won't ever be used elsewhere. This is just a
convenience--such clients could already have directly used the API on
llvm::Module directly.
Raw identifiers are backtick-delimited identifiers that can contain any
non-identifier character other than the backtick itself, CR, LF, or other
non-printable ASCII code units, and which are also not composed entirely
of operator characters.
When it's available, use an open-coded allocator function that returns
an alloca without popping if the allocator is nullptr and otherwise
calls swift_coro_alloc. When it's not available, use the malloc
allocator in the synchronous context.
Mike Ash
Kavon Farvardin
Erik Eckstein
Dario Rexin
Doug Gregor
Steven Wu
Alejandro Alonso
Arnold Schwaighofer
Slava Pestov
Nate Chandler
Michael Gottesman
Ellis Hoag
Anton Korobeynikov
John McCall
Anthony Latsis
Tobias Stadler
nate-chandler
Augusto Noronha
Tony Allevato
Konrad `ktoso` Malawski
Saleem Abdulrasool