Client code can make a best effort at emitting a key path referencing a property with its publicly exposed API, which in the common case will match what the defining module would produce as the canonical key path component representation of the declaration. We can reduce the code size impact of these descriptors by not emitting them when there's no hidden or possibly-resiliently-changed-in-the-past information about a storage declaration, having the property descriptor symbol reference a sentinel value telling client key paths to use their definition of the key path component.
Upstream has renamed the DEBUG() macro to LLVM_DEBUG. This updates swift
accordingly:
$ find . -name \*.cpp -print -exec sed -i "" -E "s/ DEBUG\(/ LLVM_DEBUG(/g" {} \;
This flag supports promoting KeyPath access violations to an error in
Swift 4+, while building the standard library in Swift 3 mode. This is
only necessary as long as the standard library continues to build in
Swift 3 mode. Once the standard library build migrates, it can all be
ripped out.
<rdar://problem/40115738> [Exclusivity] Enforce Keypath access as an error, not a warning in 4.2.
Mandatory pass will clean it up and replace it by a copy_block and
is_escaping/cond_fail/release combination on the %closure in follow-up
patches.
The instruction marks the dependence of a block on a closure that is
used as an 'withoutActuallyEscaping' sentinel.
rdar://39682865
To mark when a user of it is known to escape the value. This happens
with materializeForSet arguments which are captured and used in the
write-back. This means we need to keep the context alive until after
the write-back.
Follow-up patches to fully replace the PostponedCleanup hack in SILGen
by a mandatory SIL transformation pass to guarantee the proper lifetime
will use this flag to be more conservative when extending the lifetime.
The problem:
%pa = partial_apply %f(%some_context)
%cvt = convert_escape_to_noescape [not_guaranteed] [escaped] %pa
%ptr = %materialize_for_set(..., %cvt)
... write_back
... // <-- %pa needs to be alive until after write_back
By design, things with shared linkage are allowed to have definitions in different TUs, and we're supposed to pick one when linking or merging modules.
Add serialization layouts for rare instructions that take extra attributes. We
can continue adding bits to these layout without affecting the layout of the
vast majority of instructions.
A public subscript might have generic indexes that aren't unconditionally Hashable, or might use indexes that are retroactively made Hashable, so the property descriptor on the implementer's side can't always resiliently provide this information to the final instantiated KeyPath.
If a property or subscript is referenceable from other modules, we need to give it a descriptor so that we can reliably build an equivalent key path in or out of that module.
There are some cases that we should handle but don't yet:
- Global and static properties ought to be key-path-able someday, so we should make descriptors for them, but this might need a new key path component kind.
- Subscripts with indexes that aren't Hashable in the current module ought to get descriptors too, in case we ever support non-hashable key path components, and also because a generic subscript might be substituted with Hashable types by an external user, or an external module might post-hoc extend a type to be Hashable, so we really need to change things so that the client supplies the hashing and equality implementations for the indexes instead of the descriptor.
Will be used to verify that withoutActuallyEscaping's block does not
escape the closure.
``%escaping = is_escaping_closure %closure`` tests the reference count. If the
closure is not uniquely referenced it prints out and error message and
returns true. Otherwise, it returns false. The returned result can be
used with a ``cond_fail %escaping`` instruction to abort the program.
rdar://35525730
The obsolete llvm::HashString() was equivalent to
llvm::djbHash(seed=0) and was removed from llvm. This patch replaces
all occurences of llvm::HashString() with llvm::djbHash(seed=0), no
functional change.
The default seed of llvm::djbHash() is supposed to yield a higher
quality result that using seed=0, but changing it looks like it
affects the ordering of SIL serialization.
This is mostly intended to be used for testing at this point; in the
long run, we want to be using availability information to decide
whether to weak-link something or not. You'll notice a bunch of FIXMEs
in the test case that we may not need now, but will probably need to
handle in the future.
Groundwork for doing backward-deployment execution tests.
