Limiting the branching factor and the depth of branching #674
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Better explanation Add changelog, fix command line option Adding test cases for depth of exploration tree Fix warning
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Description
This allows the user or library to limit the exploration branching factor and branching depth. So a limit of 4 will allow us to go into 4 if-then-elses. A limit of 4 will also limit us from going into more than 4 different places when e.g. a
JUMP (symbolic expression).is performed. If the symbolic expression has more than 4 solutions, we abandon exploration.The system therefore limits the maximum number of branches explored to
k^{k}. Note that this does not limit the number of opcodes symbolically executed. If it's a straight-line program of 10000 operations, and ourkis 5, it will still work. But if there are more than 5 nested if-then-else-es, then it will stop exploring beyond a certain point.I created a new
Partialnode to account for these partial executions:TooManyBraches. This gets generated when a we have to stop exploring. Default is unlimited branches, of course, so everything works as before if this exploration limit is not set.On op of
more-symbolic, i.e. #673Checklist