The old analysis pass doesn't take into account profile data, nor does
it consider post-dominance. It primarily dealt with _fastPath/_slowPath.
A block that is dominated by a cold block is itself cold. That's true
whether it's forwards or backwards dominance.
We can also consider a call to any `Never` returning function as a
cold-exit, though the block(s) leading up to that call may be executed
frequently because of concurrency. For now, I'm ignoring the concurrency
case and assuming it's cold. To make use of this "no return" prediction,
use the `-enable-noreturn-prediction` flag, which is currently off by
default.
Although I don't plan to bring over new assertions wholesale
into the current qualification branch, it's entirely possible
that various minor changes in main will use the new assertions;
having this basic support in the release branch will simplify that.
(This is why I'm adding the includes as a separate pass from
rewriting the individual assertions)
TLDR: This makes it so that we always can parse sending/transferring but changes
the semantic language effects to be keyed on RegionBasedIsolation instead.
----
The key thing that makes this all work is that I changed all of the "special"
semantic changes originally triggered on *ArgsAndResults to now be triggered
based on RegionBasedIsolation being enabled. This makes a lot of sense since we
want these semantic changes specifically to be combined with the checkers that
RegionBasedIsolation turns on. As a result, even though this causes these two
features to always be enabled, we just parse it but we do not use it for
anything semantically.
rdar://128961672
A few things:
1. Internally except for in the parser and the clang importer, we only represent
'sending'. This means that it will be easy to remove 'transferring' once enough
time has passed.
2. I included a warning that suggested to the user to change 'transferring' ->
'sending'.
3. I duplicated the parsing diagnostics for 'sending' so both will still get
different sets of diagnostics for parsing issues... but anywhere below parsing,
I have just changed 'transferring' to 'sending' since transferring isn't
represented at those lower levels.
4. Since SendingArgsAndResults is always enabled when TransferringArgsAndResults
is enabled (NOTE not vis-a-versa), we know that we can always parse sending. So
we import "transferring" as "sending". This means that even if one marks a
function with "transferring", the compiler will guard it behind a
SendingArgsAndResults -D flag and in the imported header print out sending.
rdar://128216574
Specifically:
1. I added the "upcoming feature already enabled in this swift-version"
diagnostic.
2. I taught sil-opt that in swift-6 mode strict concurrency is enabled by
default.
I implemented this by adding a new option called swift-version. If not set, we
just leave LangOpts.EffectiveLanguageVersion alone and get whatever that default
behavior is. If it is set, we use the same version parsing infrastructure used
by the normal frontend. If the parse fails, we exit -1.
To write the test that I wanted to write to show this behavior, I also needed to
add support to sil-opt for verify-additional-prefixes which is just useful
goodness.
Running finishDiagProcessing and potentially silently exiting when -verify is
set is the correct behavior for failures later in sil-opt when running Sema or
when running SIL passes. This is incorrect behavior when just setting up the
compiler instance since in such a case, we want to hard exit -1 since this means
that a test has not properly setup the compiler instance itself. It is better to
hard fail and have the test maintainer just update its command line arguments as
appropriate.
I added a disable flag -disable-region-based-isolation-with-strict-concurrency
so that we do not need to update the current tests. It is only available when
asserts are enabled to ensure users cannot use it.
rdar://125918028
It's not thread safe and can cause false alarms in case multiple modules exist in different threads. E.g. when building swiftmodules from interfaces.
The leaking check is not important anymore because the builder APIs enforce that instructions are not leaking.
I.e. it's not possible to create an instruction without inserting it into a basic block. Also, it's not possible to remove an instruction from a block without deleting it.
rdar://122169263
There were a handful of different places trying to enable the
feature-flag when the stdlib has been built with the feature enabled.
This change cleans that up and unifies it in one spot for all sub-tools
like sil-opt and sil-func-extractor to pick-up.
Adding `move_value [lexical]` and `begin_borrow [lexical]` should happen
all the time at this point. Remove the ability to omit these
instructions and update the corresponding tests.
Merge `$<Feature>` and `hasFeature` implementations.
- `$<Feature>` did not support upcoming language features.
- `hasFeature` did not support promoted language features and also
didn't take into account `Options` in `Features.def`.
Remove `Options` entirely, it was always one of three cases:
- `true`
- `langOpts.hasFeature`
- `hasSwiftSwiftParser`
Since `LangOptions::hasFeature` should always be used anyway, it's no
longer necessary. `hasSwiftSwiftParser` can be special cased when adding
the default promoted language features (by removing those features).
Resolves rdar://117917456.
Some notes:
This is not emitted by SILGen. This is just intended to be used so I can write
SIL test cases for transfer non sendable. I did this by adding an
ActorIsolationCrossing field to all FullApplySites rather than adding it into
the type system on a callee. The reason that this makes sense from a modeling
perspective is that an actor isolation crossing is a caller concept since it is
describing a difference in between the caller's and callee's isolation. As a
bonus it makes this a less viral change.
For simplicity, I made it so that the isolation is represented as an optional
modifier on the instructions:
apply [callee_isolation=XXXX] [caller_isolation=XXXX]
where XXXX is a printed representation of the actor isolation.
When neither callee or caller isolation is specified then the
ApplyIsolationCrossing is std::nullopt. If only one is specified, we make the
other one ActorIsolation::Unspecified.
This required me to move ActorIsolationCrossing from AST/Expr.h ->
AST/ActorIsolation.h to work around compilation issues... Arguably that is where
it should exist anyways so it made sense.
rdar://118521597
Swift has some module maps it overlays on Linux and Windows that groups all of the C standard library headers into a single module. This doesn’t allow clang and C++ headers to layer properly with the OS/SDK modules. clang will set -fbuiltin-headers-in-system-modules as necessary for Apple SDKs, but Swift will need to pass that flag itself when required by its module maps.
For chains of async functions where suspensions can be statically
proven to never be required, this pass removes all suspensions and
turns the functions into synchronous functions.
For example, this function does not actually require any suspensions,
once the correct executor is acquired upon initial entry:
```
func fib(_ n: Int) async -> Int {
if n <= 1 { return n }
return await fib(n-1) + fib(n-2)
}
```
So we can turn the above into this for better performance:
```
func fib() async -> Int {
return fib_sync()
}
func fib_sync(_ n: Int) -> Int {
if n <= 1 { return n }
return fib(n-1) + fib(n-2)
}
```
while rewriting callers of `fib` to use the `sync` entry-point
when we can prove that it will be invoked on a compatible executor.
This pass is currently experimental and under development. Thus, it
is disabled by default and you must use
`-enable-experimental-async-demotion` to try it.
* [Stdlib] Add some prespecializations to the stdlib
This adds prespecializations for commonly used types to the stdlib
* Add false positives to ABI checker ignore list
* Update multithread_module.swift
* Update multithread_module.swift
* Update multithread_module.swift
Reformatting everything now that we have `llvm` namespaces. I've
separated this from the main commit to help manage merge-conflicts and
for making it a bit easier to read the mega-patch.
This is phase-1 of switching from llvm::Optional to std::optional in the
next rebranch. llvm::Optional was removed from upstream LLVM, so we need
to migrate off rather soon. On Darwin, std::optional, and llvm::Optional
have the same layout, so we don't need to be as concerned about ABI
beyond the name mangling. `llvm::Optional` is only returned from one
function in
```
getStandardTypeSubst(StringRef TypeName,
bool allowConcurrencyManglings);
```
It's the return value, so it should not impact the mangling of the
function, and the layout is the same as `std::optional`, so it should be
mostly okay. This function doesn't appear to have users, and the ABI was
already broken 2 years ago for concurrency and no one seemed to notice
so this should be "okay".
I'm doing the migration incrementally so that folks working on main can
cherry-pick back to the release/5.9 branch. Once 5.9 is done and locked
away, then we can go through and finish the replacement. Since `None`
and `Optional` show up in contexts where they are not `llvm::None` and
`llvm::Optional`, I'm preparing the work now by going through and
removing the namespace unwrapping and making the `llvm` namespace
explicit. This should make it fairly mechanical to go through and
replace llvm::Optional with std::optional, and llvm::None with
std::nullopt. It's also a change that can be brought onto the
release/5.9 with minimal impact. This should be an NFC change.
