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#2129 StackOverflowError with parallelSpeedUp on OR automaticDeobfuscation off
Author: user GTcreyon
Date created:
Type: question
Visibility: Everybody
Assigned to:
Labels: Stack size
State: closed Help

> What steps will reproduce the problem? Run `ffdec -export script folder 63old.swf` with default config. > What is the expected output? What do you see instead? In, _root.LDAttachTile should be decompiled correctly. Instead, a StackOverflowError occurs. However, this can be avoided with the alternative command: `ffdec -config autoDeobfuscation=1,parallelSpeedUp=0 -export script folder 63old.swf` Both configs need to be set as such in order to avoid the issue > What version of the product are you using? Is it "nightly build"? Which operating system do you have? 20.0.0, Arch Linux > Please provide any additional information below. If the problem is related to a SWF file, attach it here, otherwise we can't help you. This only seems to occur from the CLI. The GUI handles it fine.
Download63old.swf (14,938 KiB)
For me, it shows StackOverflowError in the GUI too - I am on Windows 11. Please see FAQ: overflowerror-even-if-i-increase-limits-in-settings-what-can-i-do This problem seems to be fixed for me, if you modify STACK_SIZE variable.
State: new→opened
Type: bug→question
Oh, that's useful. Perhaps it's simply because the script is so large?
Is there a way to increase the stack size via the CLI, without having to edit The use case is the Flash Patcher, an automatic tool for patching code into SWF files. It would be nice to allow the user to run FFDec with the appropriate stack size option out-of-the-box by specifying a CLI option, rather than having to alter their system.
In nightly 2710, you can set variable FFDEC_STACK_SIZE before running On Linux/Mac: export FFDEC_STACK_SIZE=32m ./ On Windows: set FFDEC_STACK_SIZE=32m ffdec.bat The same for FFDEC_MEMORY variable. It only works if user has not set (uncommented) these values in his ffdec.bat/sh. But I must warn you - increasing stack size requires more memory and if the PC does not have sufficient memory, the App can crash on OutOfMemory. This is why there is comment about "you can experiment with lower value". So setting it to 32m is not always the best. You better make it configurable in your software aswell.
Ad "Perhaps it's simply because the script is so large?" It is because the script has too many nested branches and FFDec calls the function to walk branches recursively and the call stack size is limited.
Makes sense to me. I'll experiment with that. Thank you.
This can be closed. The environment variable solution worked great.
State: opened→closed