Reimplement references VarDebugInfo #115030
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Some changes occurred to MIR optimizations cc @rust-lang/wg-mir-opt |
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Not sure who has expertise to review this. |
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☔ The latest upstream changes (presumably #115094) made this pull request unmergeable. Please resolve the merge conflicts. |
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Closing until we have a solution for the codegen part. |
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This feature was removed recently in #114904 because implemented unsoundly. This PR proposes a simpler re-implementation.
We introduce an additional
referencesfield inVarDebugInfo. This additional field allows to optimize out references that are only used for debuginfo:debug x => _1 _1 = &_2If debuginfo is the only use of
_1, this would becomedebug x => &_2For codegen, we associate the local
_2with the name*x. This is suboptimal, as most debugger won't understand that*xis a name, and not the dereference ofx.