The substitution is driven by a canonical type to mangled name table on ASTContext,
populated by exportability checking at the same site where the corresponding
diagnostics are suppressed. After this change, the module emitter and module
loader see hidden types differently: the emitter still sees the real types
defined in the bridging header, while the loader sees only a mangled name
wrapped in a HiddenType placeholder.
Add the module-format machinery that lets a Swift library record the
physical layout of hidden types (currently limited to C types imported via internal bridging header).
into binary modules, so downstream consumers can pull the layouts of these hidden types without
loading the internal dependency.
To test this, this change also added a frontend action to print hidden types' layouts
from both the module under compilation and all the modules being imported.
@_preInverseGenerics(except: <inverses>) is an extension of the existing
@_preInverseGenerics attribute that provides selective control over which
inverse requirements are mangled into a declaration's symbol name.
While the bare @_preInverseGenerics strips all inverse constraints
(~Copyable and ~Escapable) from mangling, the 'except:' form allows specific
inverses to be retained. This is needed when a type like Span already had
~Copyable mangled into its ABI-stable symbols and now needs to retroactively
adopt ~Escapable without changing those existing symbols. You can now express
that with `@_preInverseGenerics(except: ~Copyable)` to strip-out every inverse
except ~Copyable to preserve the pre-existing ~Copyable-containing symbols.
It requires the new experimental feature `PreInverseGenericsExcept`.
rdar://176395527
HiddenType is a new TypeBase subclass that carries a mangled name
without leaking the actual type definition. It serves as a type-slot
placeholder for stored-property types that have been elided from a
serialized binary module, so that the client side can either
(1) resolve this mangled name to the real type if the client has access to the owning module, or
(2) use the mangled name as a key to query abstract layout information also serialized in the binary module.
As an example — a library with a hidden field of a bridging-imported type:
```
// Utility.h (internal bridging header)
// typedef struct { int value; } Wrapper;
public struct S {
private var w: Wrapper
public var weight: Double
}
In the serialized module, the client's view reconstructs as:
public struct S {
private var w: @_hidden("$sSo7Wrappera")
public var weight: Double
}
```
Add a LAST_RECORD_KIND_MARKER sentinel at the end of the
options_block::RecordKind enum and a static_assert in writeHeader that
verifies the block's code width can encode every abbreviation the
writer may allocate. A future record kind that would overflow the
current code size now fails the build instead of producing a silent
malformed-module regression.
rdar://176522412
OPTIONS_BLOCK has historically been opened with a 4-bit abbreviation code size (BCBlockRAII(Out, OPTIONS_BLOCK_ID, 4) in Serializer::writeHeader), which permits at most 12 user-defined abbreviations (IDs 4–15, after the four reserved bitstream codes). New option records have been added incrementally, for certain flag combinations the writer now emits 13 or more abbreviations in OPTIONS_BLOCK, one past the 12-abbreviation ceiling that a 4-bit code size allows.
When that happens, the writer assigns the new abbreviation ID 16, which does not fit in 4 bits; BitstreamWriter::EmitCode silently truncates it to 0, which the reader interprets as END_BLOCK. OPTIONS_BLOCK is then popped prematurely, later records are reinterpreted as (invalid) content in the enclosing CONTROL_BLOCK, and the module fails to load with error: malformed compiled module. Widening the code size to 6 bits raises the cap to 60 user abbreviations (IDs 4–63), accommodates every currently-emitted record with substantial headroom.
rdar://176281964
For a given function, we might end up emitting it's definition as
object code, serialized SIL, or both. The @export, @inlinable, and
@inline(always) attributes provide control of this behavior at the
declaration level.
Centralize the query function that will look for each of these
attributes and map down to a specific "code generation model", whose 3
options follow the naming from SE-0497: interface, inlinable, and
implementation. Use this one computation to back the queries for
"always emit into client", "never emit into client", and "inlinable"
so we can't get inconsistent results from places that are doing
one-off checks for these attributes.
Generalizes how isolation is stored for SILFunctionType and
makes it possible to store not just "erased" but any future
isolation we'd need to add as well.
Add a LIBRARY_LEVEL record to the .swiftmodule options block so the
declared -library-level value survives across compilations. Without
this, imported modules have to always fell back to a path heuristic
that could only distinguish API vs SPI and never returned IPI.
rdar://174255626
Conformance entries are used for fast conformance lookup, which doesn't need to query the runtime's conformance lookup table.
A conformance entry specifies if the class conforms or does not conform to a protocol.
At runtime, a type cast instruction to an existential can directly load the witness table pointer from the VTable.
If null, the class does not conform to the protocol.
These will be used internally by the type checker to represent bindings
that are the joins and meets of types involving type variables. They
will not appear anywhere outside of the bindings code---so you won't
see them in expressions, or matchTypes(), etc.
When building the `OSLog` module, look for a variable named
`osLogStringSectionName`. It must have a string literal as its
initializer, which provides the section name where the log strings
should be emitted. The `OSLog` module should contain something like
this:
let osLogStringSectionName = "__TEXT,__logit"
When not present, the compiler will default to
`__TEXT,__oslogstring,cstring_literals`, which was previously the
hardcoded section name. Now, OSLog can customize the name.
Implements rdar://171571056
Currently only the top level dependencies get serialized in Swift modules. In
practice this is not enough information to fully replay a module import
sequence, especially when the dependencies include binary SDK modules that were
built elsewhere. In this case we cannot follow the links to its depenencies,
since they refer to paths on a different machine or unavailable CAS. During an
EBM build, the dependency scanner writes the complete list of dependencies into
a json file called the explicit Swift module map -- including the local
locations of the dependencies of binary SDK modules. Using this LLDB can replay
a module import with 100% accuracy.
rdar://170514919
Non-Escapable 'inout' arguments have a default self-dependency, regardless of
any other annotations. For example:
@_lifetime(dest: copy source)
/* DEFAULT: @_lifetime(dest: copy dest, copy source) */
func foo<T: ~Escapable>(dest: inout T, source: T)
An immortal lifetime specifier now suppresses that default. For example:
@_lifetime(dest: immortal, copy source)
/* DEFAULT: @_lifetime(dest: copy source) */
func foo<T: ~Escapable>(dest: inout T, source: T)
This is necessary because there is otherwise no other way to suppress the
default lifetime.
Fixes rdar://170016708 ([nonescapable] Support @_lifetime(immortal) to suppress
the usual inout default self-dependency)
Modify relevant portions of the type-checker and parser to allow, when the 'LiteralExpressions' experimental feature is enabled, for arbitrary integer-typed expressions in enum raw value specifiers. These expressions will be type-checked and constant-folded into an integer literal expression, keeping the current interface of 'EnumElementDecl' consistent for clients.
Previously, 'EnumRawValuesRequest' had two different "modes" which were discerned based on typechecking stage (structural | interface), where the former had the request compute all raw values, both user-specified literal expressions and computing increment-derived values as well; the latter would also type-check the user-specified expressions and compute their types.
- With the need to have enum case raw values support arbitrary integer expressions, the request ('EnumRawValuesRequest') has been refactored and simplified to *always* both compute all case raw values and perform type-checking of user-specified raw value expressions. This is done in order to allow the AST-based constant-folding infrastructure ('ConstantFoldExpression' request) to run on the expressions. Constant folding is invoked during the evaluation of 'EnumRawValuesRequest' on all user-specified raw value expressions, in order to be able to compute subsequent increment values and ensure the expressions are foldable. If they are not, i.e. if constant folding fails, a relevant diagnostic will be emitted.
- 'EnumElementDecl' continues to store the raw value expression, which is no longer a 'LiteralExpr' but rather an 'Expr'; however, the getter ('getRawValueExpr') continues to return a 'LiteralExpr' by invoking the constant-folding request on the stored value, which is guaranteed to return a cached result from a prior invocation in 'EnumRawValuesRequest', assuming it succeeded.
- Furthermore, the 'structural' request kind was previously not cached, whereas now because the request must always do the complete type-checking work, it is always cached.
Resolves rdar://168005520
The isFromAnnotation flag is set if and only if the lifetime originates from a
@lifetime or @_lifetime annotation in the source program.
isFromAnnotation==false means that the lifetime dependence checker would infer
the same lifetime if the Swift type or decl was printed without an annotation
for that dependency. More specifically, it means that the depenence was inferred
by the lifetime dependence checker.
Some dependencies on imported C/C++ decls are "inferred", but they either
correspond to explicit lifetime information in the source (smart pointers,
lifetimebound attribute) or are likely to differ from what the dependence
checker would infer. As such, we set the flag to true for all of them.
When a function type refers to a Swift declaration we get a crash during
deserialization. This patch prevents serializing the problematic clang
function types to avoid this crash.
rdar://166359524
This updates a large number of internal symbols, function names,
and types to match the final approved terminology. Matching the
surface language terminology and the compiler internals should
make the code easier for people to understand into the future.
Store the original VarDecl in the same map we use for tracking the
original wrapper var for property wrappers. This will allow us to
use the same logic to determine the original var for both.
When a custom domain is described on the command line, there is no
backing declaration for it. Serialize such custom domains by
identifier and look them up globally at the point of deserialization.
When that fails, warn and drop the annotation.
This is all a stopgap until we have a way to spell custom availability
domains in the Swift language itself.
We need to serialize the underlying type substitution map for an
inlinable function. However, there is no reason to deserialize it
eagerly, since doing so can lead to cycles. It is better for
correctness and performance to only deserialize it when needed.
Technically this fixes a regression from #84299, but the actual
problem was there all along, it was just exposed by my change
on a specific project.
Fixes rdar://163301203.
We currently disallow these by deleting them in the `swift` namespace.
This approach has several loopholes, all of which ultimately work
because we happen to define specializations of `simplify_type` for
`swift::Type`:
* `llvm::isa/cast/dyn_cast`. The deleted partial specializations will
not be selected because they are not defined in the `llvm` namespace.
* The argument is a non-const `Type`. The deleted function templates
will not be selected because they all accept a `const Type &`, and
there is a better `Y &Val` partial specialization in LLVM.
* Other casting function templates such as `isa_and_nonull` and
`cast_if_present` are not deleted.
Eliminate these loopholes by instead triggering a static assertion
failure with a helpful message upon instantiation of `CastInfo` for
`swift::Type`.
Introduce a last resort check reporting references to
implementation-only dependencies that would appear in the generated
swiftmodule. This check is applied at serialization, long after
exportability checking applied at typechecking. It should act as a back
stop to references missed by typechecking or @_implementationOnly decls
that should have been skipped.
This check is gated behind CheckImplementationOnlyStrict and should be
used with embedded only.
rdar://160697599
Implement the @export(implementation) and @export(interface) attributes
to replace @_alwaysEmitIntoClient and @_neverEmitIntoClient. Provide a
warning + Fix-It to start staging out the very-new
@_neverEmitIntoClient. We'll hold off on pushing folks toward
@_alwaysEmitIntoClient for a little longer.
Whenever we have a reference to a foreign function/variable in SIL, use
a mangled name at the SIL level with the C name in the asmname
attribute. The expands the use of asmname to three kinds of cases that
it hadn't been used in yet:
* Declarations imported from C headers/modules
* @_cdecl @implementation of C headers/modules
* @_cdecl functions in general
Some code within the SIL pipeline makes assumptions that the C names of
various runtime functions are reflected at the SIL level. For example,
the linking of Embedded Swift runtime functions is done by-name, and
some of those names refer to C functions (like `swift_retain`) and
others refer to Swift functions that use `@_silgen_name` (like
`swift_getDefaultExecutor`). Extend the serialized module format to
include a table that maps from the asmname of functions/variables over
to their mangled names, so we can look up functions by asmname if we
want. These tables could also be used for checking for declarations
that conflict on their asmname in the future. Right now, we leave it
up to LLVM or the linker to do the checking.
`@_silgen_name` is not affected by these changes, nor should it be:
that hidden feature is specifically meant to affect the name at the
SIL level.
The vast majority of test changes are SIL tests where we had expected
to see the C/C++/Objective-C names in the tests for references to
foreign entities, and now we see Swift mangled names (ending in To).
The SIL declarations themselves will have a corresponding asmname.
Notably, the IRGen tests have *not* changed, because we generally the
same IR as before. It's only the modeling at the SIL lever that has
changed.
Another part of rdar://137014448.
Xi Ge
Kavon Farvardin
Sam Pyankov
Artem Chikin
Konrad Malawski
Aidan Hall
Doug Gregor
Pavel Yaskevich
Erik Eckstein
Arnold Schwaighofer
Slava Pestov
Steven Wu
Adrian Prantl
Andrew Trick
Joe Groff
Elsa Keirouz
Meghana Gupta
Gabor Horvath
Tim Kientzle
Hamish Knight
Anthony Latsis
Alexis Laferrière