Seahorn misses error in programs with nested array indices about seahorn

[caballa]

As the warning says, packet is uninitialized because it's a local variable. Reading from uninitialized memory is undefined behavior so probably LLVM removes a big chunk of that code.

[Novak756]

Yes I can see that, however running Seahorn on something like

extern void __VERIFIER_error(void);
#define ARRAY_SIZE 4

int main(){
    long packet[ARRAY_SIZE];
    if(packet[0] == 1){
        __VERIFIER_error(); 
    }
    return 0;
}

yields sat without any warnings, so I assumed the index calls would just return non-deterministic values.
The error and warnings only occur when there are nested array accesses.

[caballa]

It depends on what LLVM decides to do with UB.
You can add option --oll=bug.ll to see the actual LLVM bitcode that it's analyzed by SeaHorn.