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a35614e539
fixes #25730 As mentioned in the issue this results in less optimized output, it always generates the explicitly called hook as a proc rather than an inline assignment. But maybe this is a reasonable trade since it only happens on explicit `=sink`/`=copy` calls. Any way to optimize it requires detecting either the type or the found hook as a trivial assignment. I am not sure how to do these, the hook isn't like destructors that propagate empty statements in `liftdestructors` (which is what `isTrivial` checks for), it needs to propagate simple assignments instead. And there is no logic for the type, `tfHasAsgn` is misleading since it only checks if the destructor is trivial, because there is no check for a trivial assignment. Did not mark as backported but the only issue I can think of is the performance issue above, otherwise it would be more correct if anything.
46 lines
798 B
Nim
46 lines
798 B
Nim
discard """
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output: '''
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246
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246
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'''
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"""
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# issue #25730
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type
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Inner[T] = object
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x: T
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Foo[T] = object
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inner: Inner[T]
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Bar[T] = object
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foo: Foo[T]
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proc `=sink`[T](a: var Inner[T], b: Inner[T]) {.nodestroy.} =
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a.x = b.x * 2
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proc `=copy`[T](a: var Inner[T], b: Inner[T]) {.nodestroy.} =
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a.x = b.x * 2
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when true:
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proc `=sink`[T](a: var Bar[T], b: Bar[T]) {.nodestroy.} =
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`=sink`(a.foo, b.foo)
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proc `=copy`[T](a: var Bar[T], b: Bar[T]) {.nodestroy.} =
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`=copy`(a.foo, b.foo)
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proc useSink() =
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let a = Bar[int](foo: Foo[int](inner: Inner[int](x: 123)))
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var b: Bar[int]
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`=sink`(b, a)
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echo b.foo.inner.x
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useSink()
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proc useCopy() =
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let a = Bar[int](foo: Foo[int](inner: Inner[int](x: 123)))
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var b: Bar[int]
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`=copy`(b, a)
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echo b.foo.inner.x
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useCopy()
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