This is a type that has ownership of a reference while allowing access to the
spare bits inside the pointer, but which can also safely hold an ObjC tagged pointer
reference (with no spare bits of course). It additionally blesses one
Foundation-coordinated bit with the meaning of "has swift refcounting" in order
to get a faster short-circuit to native refcounting. It supports the following
builtin operations:
- Builtin.castToBridgeObject<T>(ref: T, bits: Builtin.Word) ->
Builtin.BridgeObject
Creates a BridgeObject that contains the bitwise-OR of the bit patterns of
"ref" and "bits". It is the user's responsibility to ensure "bits" doesn't
interfere with the reference identity of the resulting value. In other words,
it is undefined behavior unless:
castReferenceFromBridgeObject(castToBridgeObject(ref, bits)) === ref
This means "bits" must be zero if "ref" is a tagged pointer. If "ref" is a real
object pointer, "bits" must not have any non-spare bits set (unless they're
already set in the pointer value). The native discriminator bit may only be set
if the object is Swift-refcounted.
- Builtin.castReferenceFromBridgeObject<T>(bo: Builtin.BridgeObject) -> T
Extracts the reference from a BridgeObject.
- Builtin.castBitPatternFromBridgeObject(bo: Builtin.BridgeObject) -> Builtin.Word
Presents the bit pattern of a BridgeObject as a Word.
BridgeObject's bits are set up as follows on the various platforms:
i386, armv7:
No ObjC tagged pointers
Swift native refcounting flag bit: 0x0000_0001
Other available spare bits: 0x0000_0002
x86_64:
Reserved for ObjC tagged pointers: 0x8000_0000_0000_0001
Swift native refcounting flag bit: 0x0000_0000_0000_0002
Other available spare bits: 0x7F00_0000_0000_0004
arm64:
Reserved for ObjC tagged pointers: 0x8000_0000_0000_0000
Swift native refcounting flag bit: 0x4000_0000_0000_0000
Other available spare bits: 0x3F00_0000_0000_0007
TODO: BridgeObject doesn't present any extra inhabitants. It ought to at least provide null as an extra inhabitant for Optional.
Swift SVN r22880
Some AST nodes and SIL instructions need to reference conformances for a
particular type. If that type was imported from Clang, however, the
conformance may not exist when the AST node or SIL function gets deserialized
later. The SIL case is the problem case: fragile SIL code may contain a
reference to a conformance never mentioned in the AST of the code being
compiled, and since conformances are synthesized on demand during type-checking,
this will lead to a crash. SIL deserialization isn't supposed to be doing
work on its own (though it ~can~ import new Clang decls at the moment), so
the best answer is to serialize the conformances directly, like we would with
specialized or inherited conformances.
We can probably do better here in the long run (we don't even unique
conformances like this within a module), but this should at least handle the
immediately known problem cases.
rdar://problem/18669402
Swift SVN r22857
This included a test that failed on case-sensitive filesystems. Test fixed.
(Aside: Why not just have this fail with "no such module"? Why use a different
error? Because even if "import FOO" picks up a module named 'Foo', there may
actually be a module named 'FOO' on the system (in another folder), and we
should be able to find that. Fixing that is tracked by rdar://problem/18691936.)
rdar://problem/15632996 (again)
Swift SVN r22856
Due to case-insensitive filesystems, "import foundation" can result in the
overlay module for Foundation being loaded. Everything is confused later on
because the (wrong) module name is used in manglings, leading to all sorts
of issues.
This is not the right fix for the problem, because a user really is allowed
to have modules named "foundation" and "FOUNDATION" and "Foundation" coexisting
on their system. To do that we'll want to check the actual case of a
.framework bundle or .swiftmodule file on disk and make sure it matches before
even trying to load the file. But this is a good sanity check anyway.
rdar://problem/15632996
Swift SVN r22818
SIL functions use AST GenericParamTypeDecls, but they don't have a useful
DeclContext, so they just use the AST module associated with the current
SILModule. However, when it comes time to reserialize referenced functions
with shared_external linkage (such as closures defined in fragile public
functions), the serializer was trying to cross-reference those generic
parameters rather than reserialize them, because they aren't part of the
current source file. And because these decls aren't attached to a specific
AST DeclContext, we can't properly cross-reference them---nor should we.
This commit introduces a targeted case in the cross-reference logic to force
re-serializing these declarations. In the long run we may want to reconsider
using AST GenericParamLists for SILFunctions.
rdar://problem/18673024
Swift SVN r22800
Modeling builtins as first-class function values doesn't really make sense because there's no real function value to emit, and modeling them this way complicates passes that work with builtins because they have to invent function types for builtin invocations. It's much more straightforward to have a single instruction that references the builtin by ID, along with the type information for the necessary values, type parameters, and results, so add a new "builtin" instruction that directly represents a builtin invocation. NFC yet.
Swift SVN r22690
layouts. Introduce new SIL instructions to initialize
and open existential metatype values.
Don't actually, y'know, lift any of the restriction on
existential metatypes; just pointlessly burn extra
memory storing them.
Swift SVN r22592
We serialize shared_external linkage as shared since:
1. shared_external linkage is just a hack to tell the optimizer that a
shared function was deserialized.
2. We can not just serialize a declaration to a shared_external function
since shared_external functions still have linkonce_odr linkage at the LLVM
level. This means they must be defined not just declared.
Swift SVN r22562
properties.
The main design change here is that, rather than having
purportedly orthogonal storage kinds and has-addressor
bits, I've merged them into an exhaustive enum of the
possibilities. I've also split the observing storage kind
into stored-observing and inherited-observing cases, which
is possible to do in the parser because the latter are
always marked 'override' and the former aren't. This
should lead to much better consideration for inheriting
observers, which were otherwise very easy to forget about.
It also gives us much better recovery when override checking
fails before we can identify the overridden declaration;
previously, we would end up spuriously considering the
override to be a stored property despite the user's
clearly expressed intent.
Swift SVN r22381
We currently do not serialize the body of global addressors. To make
"sil-opt swiftmodule" pass verification, we change the linkage for
the deserialized empty global addressors from public to public external.
rdar://18021024
Swift SVN r22370
I can't actually reproduce the buildbot failure that happened last night, so
hopefully it will (a) happen again, so I can investigate, or (b) not happen
again.
Swift SVN r22230
FixNum.h and BCRecordLayout.h will move down into LLVM, APINotes
will move into Clang. Get the namespaces right before we start to move
files around.
Swift SVN r22218
Now the SILLinkage for functions and global variables is according to the swift visibility (private, internal or public).
In addition, the fact whether a function or global variable is considered as fragile, is kept in a separate flag at SIL level.
Previously the linkage was used for this (e.g. no inlining of less visible functions to more visible functions). But it had no effect,
because everything was public anyway.
For now this isFragile-flag is set for public transparent functions and for everything if a module is compiled with -sil-serialize-all,
i.e. for the stdlib.
For details see <rdar://problem/18201785> Set SILLinkage correctly and better handling of fragile functions.
The benefits of this change are:
*) Enable to eliminate unused private and internal functions
*) It should be possible now to use private in the stdlib
*) The symbol linkage is as one would expect (previously almost all symbols were public).
More details:
Specializations from fragile functions (e.g. from the stdlib) now get linkonce_odr,default
linkage instead of linkonce_odr,hidden, i.e. they have public visibility.
The reason is: if such a function is called from another fragile function (in the same module),
then it has to be visible from a third module, in case the fragile caller is inlined but not
the specialized function.
I had to update lots of test files, because many CHECK-LABEL lines include the linkage, which has changed.
The -sil-serialize-all option is now handled at SILGen and not at the Serializer.
This means that test files in sil format which are compiled with -sil-serialize-all
must have the [fragile] attribute set for all functions and globals.
The -disable-access-control option doesn't help anymore if the accessed module is not compiled
with -sil-serialize-all, because the linker will complain about unresolved symbols.
A final note: I tried to consider all the implications of this change, but it's not a low-risk change.
If you have any comments, please let me know.
Swift SVN r22215
conformances (22195 to 22199).
It broke tests:
Failing Tests (4):
Swift :: Interpreter/SDK/Foundation_NSString.swift
Swift :: SIL/Serialization/deserialize_appkit.sil
Swift :: SIL/Serialization/deserialize_foundation.sil
Swift :: stdlib/NSStringAPI.swift
Swift SVN r22214
Like the Clang decls, this happens at the end of the type-checking, just as
a simple walk through the loaded decls of the loaded modules. This caught
all of the issues in this commit series and will hopefully keep us honest in
the future.
(By the way, we don't verify right when we return a deserialized decl for the
same reason we don't verify right when we return an imported decl: parts of
the decl may be delayed, and (a) we don't want to force things to be imported
or deserialized sooner than necessary, yet (b) we want to verify as much as
possible.)
rdar://problem/16968891
Swift SVN r22200
Doug had changed the comment but not the implementation -- we were still
serializing the containing module rather than the declaring nominal or
extension.
Found by enabling verification on deserialized decls (to come soon).
Swift SVN r22198
We add two more fields to SILGlobalVariable: a VarDecl and a flag to see if this
is a declaration. VarDecl is mainly used for debugger support, it is also used
to check if the variable is weak imported.
We also modify the serializer to serialize the extra two fields.
Swift SVN r21883
