This reverts commit bb16ee049d,
reversing changes made to a8d831f5f5.
It's not sufficient to solve the problem, and the choices were to do
something more complicated, or just take a simple brute force
approach. We're going with the latter.
This reverts commit ee6e190e09. It's not
sufficient to solve the problem, and the choices were to do something
more complicated, or just take a simple brute force approach. We're
going with the latter.
LinkNormal mode is used by the mandatory pipeline. It only needs
to deserialize what is necessary for code generation, that is
functions with shared linkage that must be emitted into the client.
It was only used in a few tests. Those tests now use -emit-sil instead
of -emit-silgen, with some functions marked @_transparent and a few
CHECK: lines changed now that the mandatory optimizations get to run.
Continue to emit notes for the candidates, but use different text.
Note that we can emit a typo correction fix-it even if there are
multiple candidates with the same name.
Also, disable typo correction in the migrator, since the operation
is quite expensive, the notes are never presented to the user, and
the fix-its can interfere with the migrator's own edits.
Our general guidance is that fix-its should be added on the main
diagnostic only when the fix-it is highly likely to be correct.
The exact threshold is debateable. Typo correction is certainly
capable of making mistakes, but most of its edits are right, and
when it's wrong it's usually obviously wrong. On balance, I think
this is the right thing to do. For what it's worth, it's also
what we do in Clang.
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.
Introduce a new Type node, BoundNameAliasType, which describes a
reference to a typealias that requires substitutions to produce the
underlying type. This new type node is used both for references to
generic typealiases and for references to (non-generic) typealiases
that occur within generic contexts, e.g., Array<Int>.Element.
At present, the new type node is mainly useful in preserving type
sugar for diagnostics purposes, as well as being reflected in other
tools (indexing, code completion, etc.). The intent is to completely
replace NameAliasType in the future.
(currently spelled with an underscore to indicate its WIP state)
Later commits will handle imported enums correctly and implement the
checks for switch cases.
We can encounter these when the compiler modifies an inlinable
function to break apart a struct and the struct uses a private
type for one of its fields. It's questionable whether we /should/
handle this, but meanwhile this /is/ a non-intrusive fix that
preserves the performance of non-resilient libraries.
(That is, it appears this worked in Swift 4.0, though perhaps
not all of the same optimizations kicked in.)
https://bugs.swift.org/browse/SR-6874
This is technically a source break, but the @_fixed_layout attribute
is not official yet. If anyone really cares, we can make this
conditional on -swift-version 5 later, but I'd rather not.
This change is necessary so that we can give property initializers
non-public linkage. Currently they are public, because they can be
referenced from inlinable initializers.
Now that property initializers inside a @_fixed_layout type can
only reference public symbols, they no longer have to be public,
but making that change requires a bit more work.
For now these are underscored attributes, i.e. compiler internal attributes:
@_optimize(speed)
@_optimize(size)
@_optimize(none)
Those attributes override the command-line specified optimization mode for a specific function.
The @_optimize(none) attribute is equivalent to the already existing @_semantics("optimize.sil.never") attribute
When a conformance can either be synthesized or implied, we tend to prefer
implied. However, if the implied conformance comes from a deserialized
conformance, it will lead to an incomplete conformance and cause a crash.
This is a narrow fix for SR-6105 / rdar://problem/34911378.
introduce a common superclass, SILNode.
This is in preparation for allowing instructions to have multiple
results. It is also a somewhat more elegant representation for
instructions that have zero results. Instructions that are known
to have exactly one result inherit from a class, SingleValueInstruction,
that subclasses both ValueBase and SILInstruction. Some care must be
taken when working with SILNode pointers and testing for equality;
please see the comment on SILNode for more information.
A number of SIL passes needed to be updated in order to handle this
new distinction between SIL values and SIL instructions.
Note that the SIL parser is now stricter about not trying to assign
a result value from an instruction (like 'return' or 'strong_retain')
that does not produce any.
This commit contains:
-) adding the new instructions + infrastructure, like parsing, printing, etc.
-) support in IRGen to generate global object-variables (i.e. "heap" objects) which are statically initialized in the data section.
-) IRGen for global_value which lazily initializes the object header and returns a reference to the object.
For details see the documentation of the new instructions in SIL.rst.
This avoids having to bring in all members (and extensions!) for an
outer type just to look up a nested type. In the test case attached
(reduced from the project in SR-5284), this actually led to a circular
dependency between deserialization and the importer, which resulted in
a compiler crash.
This is not a new problem, but it's more important with the release of
Swift 4, where a number of Apple SDK types are now newly imported as
member types. (The one in the original bug was
NSView.AutoresizingMask, formerly NSAutoresizingMaskOptions.) Since we
always use the Swift 4 name for cross-references, this affected
everyone, even those still compiling in Swift 3 mode.
https://bugs.swift.org/browse/SR-5284
There can be a circularity when two enums recur through each other, and deserialization currently is not set up to robustly detect and avoid these circularities. This should avoid regressions, but re-exposes some possible cases that should require recovery in mix-and-match situations. Short-term fix for rdar://problem/32337278.
Fixes a class of deserialization issues in the merge-modules
step.
The setup was the following:
- File A defines a typealias A whose underlying type is a nested
type S of a type T, defined in a different module.
- File B defines an extension of T, and the extension member's
type references A.
When deserializing A, we would proceed to deserialize the
underlying type, which references T.S. This would first deserialize
T and perform a name lookup to find S, which would deserialize all
members, including pulling in extensions. Deserialization of the
extension defined in file B would then fail, because the declaration
for A is not yet available.
We had a previous fix for these problems in the single-module case;
a per-file lookup table mapping mangled nested type names to
declarations, allowing a nested type to be deserialized without
pulling in all members and extensions of its parent type.
This patch generalizes the nested type lookup table allowing it to
be used to resolve cross-module references as well. Also, we were
only writing out the nested type table when serializing a partial
swiftmodule corresponding to a source file. Removing this check
allows the nested type table to be serialized for modules built
with WMO enabled as well, such as the standard library.
Fixes <rdar://problem/30976604> and
<https://bugs.swift.org/browse/SR-4208>.
There are a number of type witnesses that are introduced by the Clang
importer. Immediately resolve those witnesses *without* going through
the type checker, because there are cases (i.e., deserialized SIL)
where the conformance is created but there is no type checker around.
Fixes rdar://problem/30364905, rdar://problem/31053701,
rdar://problem/31565413 / SR-4565.
Also, add a third [serializable] state for functions whose bodies we
*can* serialize, but only do so if they're referenced from another
serialized function.
This will be used for bodies synthesized for imported definitions,
such as init(rawValue:), etc, and various thunks, but for now this
change is NFC.
This is like a single-threaded variant of the "lost wakeup
problem" that's all too common to anyone who's worked on
concurrent code.
When we perform lookup into a nominal type, we check if the
ASTContext's generation number is different than a cached
generation number in the nominal type. If the two numbers
differ, we walk over all loaded module files, telling them
to load any serialized extensions. Then we update the cached
generation number in the nominal type to record the fact
that we loaded any outstanding extensions.
The idea is to avoid unnecessary work if we know that no new
extensions have been added since the last name lookup.
The "bottom half" here is that when we add a new serialized
module file, we increment the ASTContext's generation number,
and then add an entry for the module file to a list.
The problem was that in between incrementing the ASTContext's
generation number and adding the module file, we would do some
work involving the ClangImporter which could in turn trigger
name lookup, which would "see" the new generation number in
the ASTContext, but not the new thing that is about to be
added, because it hasn't been added yet. So the
NominalTypeDecl's cached generation number would move forward
and the subsequent add of the module file would be "lost".
Specifically, it looks like when SerializedModuleLoader::loadAST()
calls loadedModuleFile->associateWithFileContext(), which does
some crazy ClangImporter stuff I don't understand, which in
turn can trigger a name lookup.
The fix appears to be to bump the generation number *after*
calling associateWithFileContext().
I don't completely understand what went wrong. For example,
this was dependent on the order of 'import' statements in the
input file. Of the two test cases I added, one the first one
triggered the problem -- the other test case is identical,
except the two import statements are transposed. I'm adding it
to ensure we avoid regressing in this case also.
Also I suspect it is possible to construct a test case that
does not depend on Objective-C interop or Foundation, but
again this looked tricky and I don't think the additional test
coverage on Linux would be worth the effort.
Fixes <rdar://problem/30817732>, so RxSwift now builds again on
master. Yay!
Back in December DougG added code to delay the formation of generic
environments until all declarations from a particular module had been
deserialized, to avoid circular dependencies caused by too-eager
deserialization of protocol members. This worked great for fully-built
modules, but still had some problems with module merging, the phase of
multi-file compilation where the "partial" swiftmodules that
correspond to each source file in a target are loaded and remitted as
a single swiftmodule. Fix this by picking one of the partial
swiftmodules as the representative one for delayed actions, and wait
until deserialization is complete for /all/ of the serialized ASTs in
the same target to form the generic environments.
rdar://problem/30984417
ExtensionDecls for nested generic types have multiple generic parameter
lists, one for each level of nested generic context.
We only serialized the outermost list, though. This didn't cause any
problems as far as I can see because most of the time we seem to use
the GenericSignature instead, which has the correct generic parameters.
However since we still have usages of getGenericParamsOfContext() on
deserialized DeclContexts, better safe than sorry.
I added a test; the test used to pass on master, but with the new
assertion I added, it would fail without the other changes in this
patch.
