Fix startingStackpos tracking for loop in loop #79382
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This extends the fix made earlier around proper handling of the backtracking stack in EmitLoop. If this loop is inside of another loop, then we need to preserve the startingStackpos on the backtracking stack upon successfully completing the loop, as the outer loop might iterate and cause another occurrence of this loop to run, which will then overwrite our single startingStackpos local. If that iteration backtracks, we then need to be able to pop the previous iterations startingStackpos and restore its value.
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Tagging subscribers to this area: @dotnet/area-system-text-regularexpressions Issue DetailsThis extends the fix made earlier in #79353 around proper handling of the backtracking stack in EmitLoop. If this loop is inside of another loop, then we need to preserve the startingStackpos on the backtracking stack upon successfully completing the loop, as the outer loop might iterate and cause another occurrence of this loop to run, which will then overwrite our single startingStackpos local. If that iteration backtracks, we then need to be able to pop the previous iterations startingStackpos and restore the local's value. We already do this for the other locals that impact iterations, but we should also be doing so for startingStackpos.
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...libraries/System.Text.RegularExpressions/src/System/Text/RegularExpressions/RegexCompiler.cs
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...libraries/System.Text.RegularExpressions/src/System/Text/RegularExpressions/RegexCompiler.cs
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…egularExpressions/RegexCompiler.cs
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This extends the fix made earlier in #79353 around proper handling of the backtracking stack in EmitLoop. If this loop is inside of another loop, then we need to preserve the startingStackpos on the backtracking stack upon successfully completing the loop, as the outer loop might iterate and cause another occurrence of this loop to run, which will then overwrite our single startingStackpos local. If that iteration backtracks, we then need to be able to pop the previous iteration's startingStackpos and restore the local's value. We already do this for the other locals that impact iterations, but we should also be doing so for startingStackpos.