[lldb] Fix dwim-print to not delete non-result persistent variables (#85152) #8428
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…lvm#85152) `EvaluateExpression` does not always create a new persistent result. If the expression is a bare persistent variable, then a new persistent result is not created. This means the caller can't assume a new persistent result is created for each evaluation. However, `dwim-print` was doing exactly that: assuming a new persistent result for each evaluation. This resulted in a bug: ``` (lldb) p int $j = 23 (lldb) p $j (lldb) p $j ``` The first `p $j` would not create a persistent result, and so `dwim-print` would inadvertently delete `$j`. The second `p $j` would fail. The fix is to try `expr` as a persistent variable, after trying `expr` as a frame variable. For persistent variables, this avoids calling `EvaluateExpression`. Resolves llvm#84806 rdar://124688427 (cherry picked from commit 4da2b54) (cherry-picked from commit 38b55e1)
kastiglione
deleted the
dl/next/lldb-Fix-dwim-print-to-not-delete-non-result-persistent-variables-85152
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EvaluateExpressiondoes not always create a new persistent result. If the expressionis a bare persistent variable, then a new persistent result is not created. This means
the caller can't assume a new persistent result is created for each evaluation.
However,
dwim-printwas doing exactly that: assuming a new persistent result for eachevaluation. This resulted in a bug:
The first
p $jwould not create a persistent result, and sodwim-printwouldinadvertently delete
$j. The secondp $jwould fail.The fix is to try
expras a persistent variable, after tryingexpras a framevariable. For persistent variables, this avoids calling
EvaluateExpression.Resolves llvm#84806
rdar://124688427
(cherry picked from commit 4da2b54)
(cherry-picked from commit 38b55e1)