Transform/mixin #217
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Transform/mixin #217
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Needs adaptations in getters/setters before it can be tested.
Trait getters are no longer needed.
When inheriting from Scala2 traits we sometimes encounter names with a space at the end, denoting a local variable. Drop the space because our translation scheme has no room for it.
Now also handles all supercalls. Seems to do the right thing on pos/traits.scala. But does not pass most tests because the sym transformer forces too many things.
Will print owners of symbols when displaying trees. Requires -Yprint-syms to be set also.
Motivation: Avoid needless forcing of symbols in scope. This is a problem when cloneScope is called in TreeTransforms.
The problem manifests itself when changing the owner of a class field. Being a ValDef, this is classified as a weak owner. But it's parent (the class) should not be owner-changed.
No more trait_setters are called.
Trait initializers do not have outer params; need to avoid passing outer args to them. This problem did not manifest itself before because no trait constructor calls were generated before erasure.
After Mixin, super calls can appear in statemenr sequences. They need to be typechecked and transformed using a special context.
Array types are no longer used after erasure, so the test was redundant.
Previous version could fail where the thisType widened to an explicit self type.
Since we demand that after erasure all TermRefs are SymDenotations we need to assure this when computing the denotations of term refs in new phases.
Otherwise we get binding races, e.g. for pos/t2133.scala after mixin because we create same-named symbols in subclasses, and type refs now can refer to the subclass symbol where previously they refereed to the superclass symbol. To avoid a data race the new term ref will have a fixed symbol.
Need to have Method flag set
This is reasonable because getters are only generated late in the compilation pipeline. No need to hide a getter as a val in error messages.
1. Erase unit results in getters to BoxedUnit. 2. Erase => Unit to ()Unit; was ()BoxedUnit 3. Make sure ValDefs have same type in tpt as in symbol, analogous to DefDefs.
Separate test instead of inline.
Now survives the case where a field is written x_=, dissumulating a setter.
Split into two phases, ResolveSuper before Erasure and Mixin after. Likewise GettersSetters is split into Getters and Memoize. All tests pass, except two tests fail when compiled twice. Will investigate next why.
Needs a weakening of an assertion in assertErased
Need to be treated like TermRefs.
Ig an implicit method has a result type which does not match the expected type, the new case fires. We avoid to diagnose missing arguments, because that's really confusing for an implicit method.
The fix to Types in 9bb3551 (Retract of optimization in computeDenot) allowed the two tests to compile "twice" again.
Changes owners after a phase without copying the tree. This should be more suitable for the changeOwner operations used in the tree transforms so far, which are linear, i.e. no tree duplication is needed.
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Previously, there was a switch in SymDenotation#termRef to create a WithFixedSym ref when after erasure. This was done to fix a broken test, but it's clearly incomplete. The scheme is now replaced by one which always creates WithFixedSym Termrefs after erasure.
WojciechMazur
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Backport "Backport from Metals" to 3.3 LTS
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Mixin now integrated, all tests pass.