This is the lifetime ending variant of fix_lifetime. It is a lie to the
ownership verifier that a value is being consumed along a path. Its intention is
to be used to allow for the static verification of ownership in deallocating
deinits which for compatibility with objective-c have weird ownership behavior.
See the commit merged with this commit for more information.
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.
SubstitutionList is going to be a more compact representation of
a SubstitutionMap, suitable for inline allocation inside another
object.
For now, it's just a typedef for ArrayRef<Substitution>.
Separate formal lowered types from SIL types.
The SIL type of an argument will depend on the SIL module's conventions.
The module conventions are determined by the SIL stage and LangOpts.
Almost NFC, but specialized manglings are broken incidentally as a result of
fixes to the way passes handle book-keeping of aruments. The mangler is fixed in
the subsequent commit.
Otherwise, NFC is intended, but quite possible do to rewriting the logic in many
places.
This also avoids undefined behavior when we try to look up the
ParameterConvention of a type dependent operand. Since type dependent operands
do not have a convention, this causes us to hit an assertion.
rdar://29791263
This is only enabled when semantic sil is enabled /and/ we are not parsing
unqualified SIL.
*NOTE* To properly write tests for this, I had to rework how we verified
Branch/CondBranch insts to be actually correct (instead of pseudo-correct). I
have to put this functionality together in order to write tests.
rdar://29791263
The reason why I am introducing special instructions is so I can maintain the
qualified ownership API wedge in between qualified SIL and the rest of the ARC
instructions that are pervasively used in the compiler.
These instructions in the future /could/ be extended to just take @sil_unmanaged
operands directly, but I want to maintain flexibility to take regular
non-trivial operands in the short term.
rdar://29791263
This means using a struct so we can put methods on the struct and using an
anonymous enum to create namespaced values. Specifically:
struct SILArgumentConvention {
enum : uint8_t {
Indirect_In,
Indirect_In_Guaranteed,
Indirect_Inout,
Indirect_InoutAliasable,
Indirect_Out,
Direct_Owned,
Direct_Unowned,
Direct_Deallocating,
Direct_Guaranteed,
} Value;
SILArgumentConvention(decltype(Value) NewValue)
: Value(NewValue) {}
operator decltype(Value)() const {
return Value;
}
ParameterConvention getParameterConvention() const {
switch (Value) {
...
}
}
bool isIndirectConvention() const {
...
}
};
This allows for:
1. Avoiding abstraction leakage via the enum type. If someone wants to use
decltype as well, I think that is enough work that the leakage is acceptable.
2. Still refer to enum cases like we are working with an enum class
(e.g. SILArgumentConvention::Direct_Owned).
3. Avoid using the anonymous type in function arguments due to an implicit
conversion.
4. And most importantly... *drum roll* add methods to our enums!
This is the first verifier for SemanticSIL. The verifier is very simple and
verifies that given a SILValue V, V->getOwnershipKind() returns an ownership
kind compatible with all of V's user instructions.
This is implemented by adding a new method to SILInstruction:
SILInstruction::verifyOperandOwnership()
This method creates an instance of the visitor OwnershipCompatibilityUseChecker
and then has the instance visit this.
The OwnershipCompatibilityUseChecker is a SILInstructionVisitor that for a given
instruction verifies that the given SILInstruction's operand SILValue's produce
ValueOwnershipKind that are compatible with the SILInstruction. The reason why
it is implemented as a visitor is to ensure that a warning is produced if a new
instruction is added and a method on the OwnershipCompatibleUseChecker isn't
added.
Keep in mind that this is just the first verifier and the full verifier (that
also verifies dataflow) is built on top of it. The reason why this separate API
to the use verifier is exposed is that exposing the checker enables us to place
an assert in SILBuilder to diagnose any places where SIL ownership is violated
immediately when the violation occurs allowing for an easy debugging experience
for compiler writers. This assert is a key tool that I am going to be using to
make SILGen conform to the SIL Ownership Model.
Again, this will be behind the -enable-semantic-sil flag, so normal development
will be unaffected by this change.
rdar://29671437
This was in the first high level ARC instruction proposal, but I have not needed
it until now. The use case for this is to ahandle strong_retain_unowned (which
takes in an unowned value, asserts it is still alive, performs a strong_retain,
and returns the @owned value). This @owned value needs a destroy_value.
rdar://29671437
We just never needed this information before. And I need it now for the SIL
Ownership Verifier to cleanly get the result info so I can determine the
ownership convention of an ApplyInstBase's return value.
rdar://29671437
There's no longer a single element type to speak of. Update uses to either iterate all box fields or to assert that they're working with a single-field box.
This was made redundant by typed boxes, and the type operand was already removed from textual SIL, but the field was never removed from the instruction's in memory representation. It becomes wrong in the face of compound boxes with layout.
We don't want the machine calling conventions for closure invocation functions to necessarily be tied to the convention for normal thin functions or methods. NFC yet; for now, 'closure' follows the same behavior as the 'method' convention, but as part of partial_apply simplification it will be a requirement that partial_apply takes a @convention(closure) function and a box and produces a @convention(thick) function from them.
