This generalizes a hack where re-abstraction thunks become fragile on contact
with fragile functions.
The old policy was:
- [fragile] functions always serialized
- [reabstraction_thunk] transitively referenced from fragile always serialized
The new policy is:
- [serialized] functions always serialized
- [serializable] functions transitively referenced from serialized functions
are always serialized
- Most kinds of thunks can now be [serializable], allowing them to be shared
between serialized and non-serialized code without any issues, as long as the
body of the thunk is sufficiently "simple" (doesn't reference private
symbols or performs direct access to resilient types)
Instead of appending a character for each substitution, we now prefix the substitution with the repeat count, e.g.
AbbbbB -> A5B
The same is done for known-type substitutions, e.g.
SiSiSi -> S3i
This significantly shrinks mangled names which contain large lists of the same type, like
func foo(_ x: (Int, Int, Int, Int, Int, Int, Int, Int, Int, Int, Int, Int))
rdar://problem/30707433
In the case where we already have a guaranteed value, the borrow operation will
just return the guaranteed manage value. Thus it is ok to always just perform
the borrow unconditionally.
rdar://29791263
This ensures that ownership is properly propagated forward through the use-def
graph.
This was the work that was stymied by issues relating to SILBuilder performing
local ARC dataflow. I ripped out that local dataflow in 6f4e2ab and added a
cheap ARC guaranteed dataflow pass that performs the same optimization.
Also in the process of doing this work, I found that there were many SILGen
tests that were either pattern matching in the wrong functions or had wrong
CHECK lines (for instance CHECK_NEXT). I fixed all of these issues and also
expanded many of the tests so that they verify ownership. The only work I left
for a future PR is that there are certain places in tests where we are using the
projection from an original value, instead of a copy. I marked those with a
message SEMANTIC ARC TODO so that they are easy to find.
rdar://28685236
The commit was reverted because of a regression in the
Prototypes/CollectionTransformers test. I believe the root
cause was an escape analysis bug, which is fixed in my
previous commit.
If the thunk's type otherwise did not involve type parameters, we
would still pass around the generic parameters from the caller's
context, which is wasteful.
This would manifest as crashes in IRGen when bridging a block
taking another block in generic context.
- When emitting a re-abstraction thunk, make it pseudogeneric if
its parent function is pseudogeneric. This ensures we don't
try to get runtime type metadata when it doesn't exist.
- Mangle pseudogeneric-ness of a reabstraction thunk correctly.
Otherwise we could emit thunks with different signatures under
the same mangling.
- Only set the pseudogeneric attribute if the thunk has a generic
signature, since otherwise the mangling is no longer unique.
Fixes <rdar://problem/27718566>.
* [ClangImporter] Remove importer-based NS stripping.
As Tony puts it, in the end we wound up with more Foundation
declarations imported as members or keeping "NS" than those that
dropped it, and any further decisions will be made on a case-by-case
basis. Move all of the existing cases of prefix-stripping into
Foundation's API notes and drop the logic from the compiler.
Tested by dumping the generated interface for Foundation and its
submodules for both macOS and the iOS simulator, and comparing the
results. A few cases did slip through here because of the interaction
between "SwiftName" and "Availability: nonswift".
The next commit will re-add "NS" to some stragglers that we missed.
rdar://problem/26880017
* APINotes: Add "NS" back to a few types.
NSKeyedUnarchiverDelegate
NSKeyedArchiverDelegate
NSTextCheckingTypes
NSBinarySearchingOptions
NSEnumerationOptions
NSSortOptions
More rdar://problem/26880017
* Remove now-redundant SwiftNames from API notes.
No change observed in the generated interface of Foundation and its
submodules.
Finishes rdar://problem/26880017.
This flips the switch to have @noescape be the default semantics for
function types in argument positions, for everything except property
setters. Property setters are naturally escaping, so they keep their
escaping-by-default behavior.
Adds contentual printing, and updates the test cases.
There is some further (non-source-breaking) work to be done for
SE-0103:
- We need the withoutActuallyEscaping function
- Improve diagnostics and QoI to at least @noescape's standards
- Deprecate / drop @noescape, right now we allow it
- Update internal code completion printing to be contextual
- Add more tests to explore tricky corner cases
- Small regressions in fixits in attr/attr_availability.swift
along with recent policy changes:
- For expression types that are not specifically handled, make sure to
produce a general "unused value" warning, catching a bunch of unused
values in the testsuite.
- For unused operator results, diagnose them as uses of the operator
instead of "calls".
- For calls, mutter the type of the result for greater specificity.
- For initializers, mutter the type of the initialized value.
- Look through OpenExistentialExpr's so we can handle protocol member
references propertly.
- Look through several other expressions so we handle @discardableResult
better.
Also fixes a leak I introduced with the String -> NSString bridging;
we're always dealing with guaranteed +0, so borrow rather than forward
the "self" argument.
Provide a general mechanism for bridging from a Swift value type to
its corresponding Objective-C class type through the
_bridgeToObjectiveC witness of the appropriate _ObjectiveCBridgeable
protocol conformance. Only enable this new code for bridging String ->
NSString and work through the issues that crop up.
We cannot actually *delete* the _convertStringtoNSString entrypoint
yet, because there is some code that is depending on it indirectly;
I'll address that separately as part of the continued generalization
of the _ObjectiveCBridgeable mechanism.
Similarly to how we've always handled parameter types, we
now recursively expand tuples in result types and separately
determine a result convention for each result.
The most important code-generation change here is that
indirect results are now returned separately from each
other and from any direct results. It is generally far
better, when receiving an indirect result, to receive it
as an independent result; the caller is much more likely
to be able to directly receive the result in the address
they want to initialize, rather than having to receive it
in temporary memory and then copy parts of it into the
target.
The most important conceptual change here that clients and
producers of SIL must be aware of is the new distinction
between a SILFunctionType's *parameters* and its *argument
list*. The former is just the formal parameters, derived
purely from the parameter types of the original function;
indirect results are no longer in this list. The latter
includes the indirect result arguments; as always, all
the indirect results strictly precede the parameters.
Apply instructions and entry block arguments follow the
argument list, not the parameter list.
A relatively minor change is that there can now be multiple
direct results, each with its own result convention.
This is a minor change because I've chosen to leave
return instructions as taking a single operand and
apply instructions as producing a single result; when
the type describes multiple results, they are implicitly
bound up in a tuple. It might make sense to split these
up and allow e.g. return instructions to take a list
of operands; however, it's not clear what to do on the
caller side, and this would be a major change that can
be separated out from this already over-large patch.
Unsurprisingly, the most invasive changes here are in
SILGen; this requires substantial reworking of both call
emission and reabstraction. It also proved important
to switch several SILGen operations over to work with
RValue instead of ManagedValue, since otherwise they
would be forced to spuriously "implode" buffers.
Having a separate address and container value returned from alloc_stack is not really needed in SIL.
Even if they differ we have both addresses available during IRGen, because a dealloc_stack is always dominated by the corresponding alloc_stack in the same function.
Although this commit quite large, most changes are trivial. The largest non-trivial change is in IRGenSIL.
This commit is a NFC regarding the generated code. Even the generated SIL is the same (except removed #0, #1 and @local_storage).
when working with autoreleased result conventions, and stop
emitting autorelease_return and strong_retain_autoreleased in
SILGen.
The previous representation, in which strong_retain_autoreleased
was divorced from the call site, allowed it to "wander off" and
be cloned. This would at best would break the optimization, but
it could also lead to broken IR due to some heroic but perhaps
misguided efforts in IRGen to produce the exact required code
pattern despite the representational flaws.
The SIL pattern for an autoreleased result now looks exactly
like the pattern for an owned result in both the caller and
the callee. This should be fine as long as interprocedural
optimizations are conservative about convention mismatches.
Optimizations that don't wish to be conservative here should
treat a convention mismatch as an autorelease (if the callee
has an autoreleased result) or a retain (if the formal type
of the call has an autoreleased result).
Fixes rdar://23810212, which is an IRGen miscompile after the
optimizer cloned a strong_retain_autoreleased. There's no
point in adding this test case because the new SIL pattern
inherently prevents this transformation by construction.
The 'autorelease_return' and 'strong_retain_autoreleased'
instructions are now dead, and I will remove them in a
follow-up commit.
- If a @convention(block) function parameter was also marked @noescape, then during type-checking, we would accidentally propagate the convention directly onto a literal closure expr, instead of going through a function_conversion, which SILGen didn't handle. Fixes rdar://problem/23261912.
- If an Objective-C API declared a block parameter with a _Nonnull return of a bridged type, such as NSString *_Nonnull, then native-to-bridged thunking would fail to recognize this case, since we still bridge to an Optional type in the lowered ObjC interface. Fixes rdar://problem/23285766.
And include some supplementary mangling changes:
- Give the first generic param (depth=0, index=0) a single character mangling. Even after removing the self type from method declaration types, 'Self' still shows up very frequently in protocol requirement signatures.
- Fix the mangling of generic parameter counts to elide the count when there's only one parameter at the starting depth of the mangling.
Together these carve another 154KB out of a debug standard library. There's some awkwardness in demangled strings that I'll clean up in subsequent commits; since decl types now only mangle the number of generic params at their own depth, it's context-dependent what depths those represent, which we get wrong now. Currying markers are also wrong, but since free function currying is going away, we can mangle the partial application thunks in different ways.
Swift SVN r32896
'Ss' appears in manglings tens of thousands of times in the standard library and is also incredibly frequent in other modules. This alone is enough to shrink the standard library by 59KB.
Swift SVN r32409
Swift generates two entry points to @objc methods where one of
them is a thunk, and the inliner happily inlines the swift code
into the @objc thunk, effectively doubling the code size of some
@objc classes.
The performance inliner already knows not to inline large functions
into callers that are marked as thunks. This commit adds the [thunk]
attribute to the @objc thunks in an attempt to reduce code size.
rdar://22403108
Swift SVN r31498
These classes don't show up well in generated headers (rdar://problem/20855568),
can't actually be allocated from Objective-C (rdar://problem/17184317), and
make the story of "what is exposed to Objective-C" more complicated. Better
to just disallow them.
All classes are still "id-compatible" in that they can be converted to
AnyObject and passed to Objective-C, they secretly implement NSObjectProtocol
(via our SwiftObject root class), and their members can still be individually
exposed to Objective-C.
The frontend flag -disable-objc-attr-requires-foundation-module will disable
this requirement as well, which is still necessary for both the standard
library and a variety of tests I didn't feel like transforming.
Swift SVN r29760
to not drop optionals in memory all the time. We now generate a lot better code
for them in many cases. This makes generated SIL more readable and should help
-O0 perf.
This is progress towards <rdar://problem/20642198> SILGen shouldn't be dropping optionals into memory all the time
Swift SVN r28102
registers instead of eagerly dumping them in memory and operating on
them by-address. This avoids a lot of temporaries and traffic to
manipulate them.
As part of this, add some new SGF::getOptionalNoneValue/getOptionalSomeValue
helper methods for forming loading optional values.
Many thanks to JoeG for helping with the abstraction difference change in
getOptionalSomeValue.
Swift SVN r27537
This is new attribute we're using to coalesce @thin, @objc_block, and @cc, and to extend to new uses like C function pointer types. Parse the new attribute, but preserve support for the old attributes, and print with the old attributes for now to separate out test changes. Migration fixits and test updates to come. I did take the opportunity here to kill off the '@cc(cdecl)' hack for AST-level function pointer types, which are now only spelt with @convention(c).
Swift SVN r27247
The only caveat is that:
1. We do not properly recognize when we have a let binding and we
perform a guaranteed dynamic call. In such a case, we add an extra
retain, release pair around the call. In order to get that case I will
need to refactor some code in Callee. I want to make this change, but
not at the expense of getting the rest of this work in.
2. Some of the protocol witness thunks generated have unnecessary
retains or releases in a similar manner.
But this is a good first step.
I am going to send a large follow up email with all of the relevant results, so
I can let the bots chew on this a little bit.
rdar://19933044
Swift SVN r27241
