Verified that lexical lifetimes DO NOT result in a method call to a weak
reference resulting in a strong reference to the object. Consequently,
even with lexical lifetimes enabled, it is still possible, within a
single scope, for the first method call to an object weakly referenced
to occur but for the second such call not to because the object will
have been deallocated.
Verified that when a __consuming method calls a function which takes a
closure that captures self weakly, self is not deallocated until the
call returns. (Note that this is a behavioral change from what occurs
when lexical borrow scopes are disabled; in that case, self is
deallocated before the call to the function.)
Covers a missing case in codable synthesis for enums with argument
payloads that have internal and external labels. When the name of the
var decl is used, the internal name of the parameter becomes the key
instead of the API name. In this case, this causes an invalid reference
to an enum case with the internal name as an argument to be synthesized
in the derived Decodable conformance which (hopefully) crashes
downstream.
rdar://86339848
These fail with -requirement-machine-protocol-signatures=verify because
the GSB produces incorrect output. Enable the requirement machine
unconditionally for these tests, bypassing verification.
A new file test/Generics/same_type_requirements_in_protocol.swift
contains reduced versions of all of the failures, with FileCheck
used to confirm the exact requirement signature output.
The effect of passing -enable-copy-propagation is both to enable the
CopyPropagation pass to shorten object lifetimes and also to enable
lexical lifetimes to ensure that object lifetimes aren't shortened while
a variable is still in scope and used.
Add a new flag, -enable-lexical-borrow-scopes=true to override
-enable-copy-propagation's effect (setting it to ::ExperimentalLate) on
SILOptions::LexicalLifetimes that sets it to ::Early even in the face of
-enable-copy-propagation. The old flag -disable-lexical-lifetimes is
renamed to -enable-lexical-borrow-scopes=false but continues to set that
option to ::Off even when -enable-copy-propagation is passed.
* add an option to add freestanding to the Darwin platform, so that
to get expected compile behaviours (e.g. setting the install name)
* rework testing configuration to relax assumptions about freestanding
* add a preset to test such configuration (at least for PR testing)
Addresses rdar://85465396
Verify that lexical-lifetimes and copy-propagation interact correctly to
keep objects named by variables alive in a couple interesting cases:
unsafe pointers, synchronization point calls.
With multi-statement closure inference enabled "outer candidates"
hack needs to be careful with its use of `isInvalid()` because some
of the declarations lookup finds might be coming from a multi-statement
closure that being type-checked, such declarations have to be avoided
as candidates, otherwise calling `isInvalid` on them results in a circular
type-checking.
Resolves: rdar://85843677
Previously, both swift-frontend and sil-opt put lexical lifetimes behind
a flag named -enable-experimental-lexical-lifetimes. That's redundant.
Here, the experimental portion of the name is dropped.
