AllowOverflow option to avoid checking int range

[Hecate2]

unchecked((int)bigInteger))
Will conflict. Draft for now.

[Hecate2]

Changed the methodology. Skip range checks and throws with compilation option

[Hecate2]

Need a way to compile neo-devpack-dotnet\tests\Neo.Compiler.CSharp.TestContracts\Contract_BigInteger.cs with SimulateOverflow=true

[Hecate2]

Need a way to compile neo-devpack-dotnet\tests\Neo.Compiler.CSharp.TestContracts\Contract_BigInteger.cs with SimulateOverflow=true

Allowed CompilationOptions to be used in tests.
TestGasConsume is set to false.

[Jim8y]

This name is so scary....

[Jim8y]

this can save tons of gas, yes,,,,,, but,,,,,,,

[Jim8y]

rather than allow overflow, i think biginteger only is better

[shargon]

We should not save gas if the security is involved

[shargon]

Sorry miss click

[Hecate2]

We should not save gas if the security is involved

No security problem is involved. This is just handling all int, long, short as BigInteger.

[Hecate2]

rather than allow overflow, i think biginteger only is better

Sometimes it's impossible to write BigInteger everywhere literally in codes. For example, shifting operations (>> and <<) in C# supports only int as the shifted count of bits. Also indexes of arrays have to be int. Then we have to write an explicit coversion (int) which wastes a range check.

[Hecate2]

And our current default settings (with or without my PR) are --checked=false (--allow-overflow=false). This allows silent overflows (from int.MaxValue to int.MinValue, without or without my PR). I think this is even more dangerous. Maybe it's better to have default as --checked=false --allow-overflow=true, or --checked=true --allow-overflow=false

[shargon]

we should detect unchecked keyword

[Jim8y]

@shargon please review

[Jim8y]

This is an option that should be false by default, so after you @shargon reviewed, please dont merge it, i will update the test to remove the option and revert gas change.

[shargon]

I still don't know why we need this option, which is the use case?

[Jim8y]

I still don't know why we need this option, which is the use case?

where user can handle the integer range and no need to do automatic range check. currently, every numerous operation requires a range check, its expensive.

[shargon]

I still don't know why we need this option, which is the use case?

where user can handle the integer range and no need to do automatic range check. currently, every numerous operation requires a range check, its expensive.

expensive not because it's required for safety

[shargon]

We should leave the test as before, only create one test for this specific case

[Hecate2]

Done

[shargon]

Can we discuss this pe in the meeting?

[Hecate2]

Can we discuss this pe in the meeting?

That's really great

[Jim8y]

gas examples to demonstrate gas saving. /or use biginteger as much as possible

[shargon]

Take a look to #1249