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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.
25 lines
1.0 KiB
Plaintext
25 lines
1.0 KiB
Plaintext
// RUN: %target-sil-opt -assume-parsing-unqualified-ownership-sil %s | %FileCheck %s
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import Swift
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public protocol mmOutputStreamType {
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/// Append the given `string` to this stream.
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mutating func write(string: String)
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}
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public protocol mmStreamable {
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func writeTo<Target : mmOutputStreamType>(target: inout Target)
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}
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// CHECK-LABEL: sil @test : $@convention(thin) () -> () {
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sil @test : $() -> () {
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bb0:
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%281 = alloc_stack $mmStreamable
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%282 = open_existential_addr mutable_access %281 : $*mmStreamable to $*@opened("01234567-89ab-cdef-0123-000000000000") mmStreamable
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// CHECK: witness_method $@opened({{.*}}) mmStreamable, #mmStreamable.writeTo!1
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%293 = witness_method $@opened("01234567-89ab-cdef-0123-000000000000") mmStreamable, #mmStreamable.writeTo!1, %282 : $*@opened("01234567-89ab-cdef-0123-000000000000") mmStreamable : $@convention(witness_method) @callee_owned <T_0_0, T_1_0 where T_0_0 : mmStreamable, T_1_0 : mmOutputStreamType> (@inout T_1_0, @inout T_0_0) -> ()
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dealloc_stack %281 : $*mmStreamable
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%1 = tuple ()
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return %1 : $()
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}
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