When we're looking up all associated types with the same name in order
to find the right archetype anchor, skip extension members to avoid
circular deserialization.
Discovered while investigating <rdar://problem/30248571>.
Once we move to a copy-on-write implementation of existential value buffers we
can no longer consume or destroy values of an opened existential unless the
buffer is uniquely owned.
Therefore we need to track the allowed operation on opened values.
Add qualifiers "mutable_access" and "immutable_access" to open_existential_addr
instructions to indicate the allowed access to the opened value.
Once we move to a copy-on-write implementation, an "open_existential_addr
mutable_access" instruction will ensure unique ownership of the value buffer.
This has the effect of propagating the search path to the clang importer as '-iframework'.
It doesn't affect whether a swift module is treated as system or not, this can be done as follow-up enhancement.
Previously looking up an extension would result in all extensions for
types with the same name (nested or not) being deserialized; this
could even bring in base types that had not been deserialized yet. Add
in a string to distinguish an extension's base type; in the top-level
case this is just a module name, but for nested types it's a full
mangled name.
This is a little heavier than I'd like it to be, since it means we
mangle names and then throw them away, and since it means there's a
whole bunch of extra string data in the module just for uniquely
identifying a declaration. But it's correct, and does less work than
before, and fixes a circularity issue with a nested type A.B.A that
apparently used to work.
https://bugs.swift.org/browse/SR-3915
Introduce an algorithm to canonicalize and minimize same-type
constraints. The algorithm itself computes the equivalence classes
that would exist if all explicitly-provided same-type constraints are
ignored, and then forms a minimal, canonical set of explicit same-type
constraints to reform the actual equivalence class known to the type
checker. This should eliminate a number of problems we've seen with
inconsistently-chosen same-type constraints affecting
canonicalization.
Every other declaration kind gets this for free in its interface type,
but properties don't. Just add a bit, it's simple enough.
rdar://problem/30289803
It was checking the wrong predicate, and therefore failing to mark
inherited default arguments as actually being inherited.
While here, explicitly clear out default arguments from non-inherited
cloned parameter lists. I don't think this case can come up today, but
it's better to be correct when we do hit it.
rdar://problem/30167924
Textual SIL was sometimes ambiguous when SILDeclRefs were used, because the textual representation of SILDeclRefs was the same for functions that have the same name, but different signatures.
There's a class of errors in Serialization called "circularity
issues", where declaration A in file A.swift depends on declaration B
in file B.swift, and B also depends on A. In some cases we can manage
to type-check each of these files individually due to the laziness of
'validateDecl', but then fail to merge the "partial modules" generated
from A.swift and B.swift to form a single swiftmodule for the library
(because deserialization is a little less lazy for some things). A
common case of this is when at least one of the declarations is
nested, in which case a lookup to find that declaration needs to load
all the members of the parent type. This gets even worse when the
nested type is defined in an extension.
This commit sidesteps that issue specifically for nested types by
creating a top-level, per-file table of nested types in the "partial
modules". When a type is in the same module, we can then look it up
/without/ importing all other members of the parent type.
The long-term solution is to allow accessing any members of a type
without having to load them all, something we should support not just
for module-merging while building a single target but when reading
from imported modules as well. This should improve both compile time
and memory usage, though I'm not sure to what extent. (Unfortunately,
too many things still depend on the whole members list being loaded.)
Because this is a new code path, I put in a switch to turn it off:
frontend flag -disable-serialization-nested-type-lookup-table
https://bugs.swift.org/browse/SR-3707 (and possibly others)
Textual SIL was sometimes ambiguous when SILDeclRefs were used, because the textual representation of SILDeclRefs was the same for functions that have the same name, but different signatures.
When enumerating requirements, always use the archetype anchors to
express requirements. Unlike "representatives", which are simply there
to maintain the union-find data structure used to track equivalence
classes of potential archetypes, archetype anchors are the
ABI-stable canonical types within a fully-formed generic signature.
The test case churn comes from two places. First, while
representatives are *often* the same as the archetype anchors, they
aren't *always* the same. Where they differ, we'll see a change in
both the printed generic signature and, therefore, it's
mangling.
Additionally, requirement inference now takes much greater
care to make sure that the first types in the requirement follow
archetype anchor ordering, so actual conformance requirements occur in
the requirement list at the archetype anchor---not at the first type
that is equivalent to the anchor---which permits the simplification in
IRGen's emission of polymorphic arguments.
Piggybacks some resilience diagnostics onto the availability
checking code.
Public and versioned functions with inlineable bodies can only
reference other public and internal entities, since the SIL code
for the function body is serialized and stored as part of the
module.
This includes @_transparent functions, @_inlineable functions,
accessors for @_inlineable storage, @inline(__always) functions,
and in Swift 4 mode, default argument expressions.
The new checks are a source-breaking change, however we don't
guarantee source compatibility for underscored attributes.
The new ABI and tests for the default argument model will come in
subsequent commits.
Like c70a5a5d67, but for deserialization. This was causing assertion
failures during the merge-module step of building a module that had a
private/fileprivate protocol with an associated type because the
associated type wouldn't have a valid private discriminator (because
the original source file didn't consider it to be private).
https://bugs.swift.org/browse/SR-2576
The handling of SIL box types in both deserialization and in the SIL
parser assumed that the number of substitutions in the box type would
be equivalent to the number of generic parameters. This assumption is
incorrect when the generic signature adds requirements to an
associated type.
Fixes rdar://problem/29740594.
This "fixes" two issues:
- The name of a non-public typealias would leak into the public
interface if the extension had any public members.
- A common pattern of defining a platform-specific typealias for an
imported class and then extending that type would lead to
circularity when trying to deserialize the typealias. We /shouldn't/
be loading the extension at that point, but fixing that would be
much harder.
The "right" answer is to (a) check that the typealias is public if the
extension has any public members, and (b) somehow ensure there is no
circularity issue (either by not importing the extension as a result
of importing the typealias, or by the extension being able to set its
sugared base type later).
rdar://problem/29694978
Use a syntax that declares the layout's generic parameters and fields,
followed by the generic arguments to apply to the layout:
{ var Int, let String } // A concrete box layout with a mutable Int
// and immutable String field
<T, U> { var T, let U } <Int, String> // A generic box layout,
// applied to Int and String
// arguments
Store leading a trailing "trivia" around a token, such as whitespace,
comments, doc comments, and escaping backticks. These are syntactically
important for preserving formatting when printing ASTs but don't
semantically affect the program.
Tokens take all trailing trivia up to, but not including, the next
newline. This is important to maintain checks that statements without
semicolon separators start on a new line, among other things.
Trivia are now data attached to the ends of tokens, not tokens
themselves.
Create a new Syntax sublibrary for upcoming immutable, persistent,
thread-safe ASTs, which will contain only the syntactic information
about source structure, as well as for generating new source code, and
structural editing. Proactively move swift::Token into there.
Since this patch is getting a bit large, a token fuzzer which checks
for round-trip equivlence with the workflow:
fuzzer => token stream => file1
=> Lexer => token stream => file 2 => diff(file1, file2)
Will arrive in a subsequent commit.
This patch does not change the grammar.
Keep in mind that these are approximations that will not impact correctness
since in all cases I ensured that the SIL will be the same after the
OwnershipModelEliminator has run. The cases that I was unsure of I commented
with SEMANTIC ARC TODO. Once we have the verifier any confusion that may have
occurred here will be dealt with.
rdar://28685236
Recently I changed the ArchetypeBuilder is minimize requirements
in generic signatures. However substitution lists still contained
all recursively-expanded nested types.
With recursive conformances, this list becomes potentially
infinite, so we can't expand it out anymore. Also, it is just
a waste of time to have them there.
This ensures that we can write FileCheck patterns that match the end of sil
functions. Just using a FileCheck pattern against a brace is not sufficient in
the context of checking the SIL emitted by SILGen. This is because we could match a
different function's body and match the closing brace against the other
function's end brace.
With this change, one can be specific by checking:
// CHECK: } {{.*}} end sil function '<mangled name>'
The inspiration for this change is rdar://28685236. While updating SILGen tests
for that I have found many instances of SILGen tests pattern matching against
the wrong function bodies. This change will allow me to eliminate these problems
robustly.
rdar://29077869
Quiz: What does @_transparent on an extension actually *do*?
1) Make all members @_transparent?
2) Allow your members to be @_transparent?
3) Some other magical effect that has nothing to do with members?
The correct answer is 1), however a few places in the stdlib defined
a @_transparent extension and then proceeded to make some or all members
also @_transparent, and in a couple of places we defined a @_transparent
extension with no members at all.
To avoid cargo culting and confusion, remove the ability to make
@_transparent extensions altogether, and force usages to be explicit.
