Regular Expression causes LabVIEW crash

[VitSlaby]

This VI causes my LV 2021 32bit to crash, but not with 64bit LV. Is there something wrong with the regex itself? On regex101 it works flawlessly.

[PalanivelThiruvenkadam]

Even it crashes LV2023 (32bit).

Note: I don't have 64bit installed

[VitSlaby]

Some more investigation - if I shorten the string part between the "recipeAttributeList", it works and executes in no time. I did some benchmark with putting more and more text in the string input and for me it stops working at ~ 2780 characters, see the example. No memory raise detected.

[instrumento]

I have a regex example that crashes LabVIEW 2022Q3 64 bits by calling Search and Replace String.

Pretty sure some excessive greedy backtracking is causing the problem and we've replaced this with something that doesn't crash, though maybe LabVIEW could just error out somehow and not go puff.

[billko]

Is it a crash or does it just return an error? LV regex I think is based on PCRE so will return an error on encountering a null character.

[instrumento]

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@billko wrote:

Is it a crash or does it just return an error? LV regex I think is based on PCRE so will return an error on encountering a null character.

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Hard crash.  No nulls in the string.  Probably recursion / out of stack space when doing greedy backtracking.