Throw Detection in Call Analysis

[ds5678]

It might be useful to detect exception throws and report their use as injected attributes in Call Analysis.

public sealed class ThrowsAttribute : Attribute
{
    public Type Type;
}

Notes from the Discord conversation:

• Just checking for il2cpp_raise_exception isn't enough.
• Il2cpp has exception helper functions so we have to look for a function which loads two strings - "System" and the name of the exception type.
• These helpers can be nested several layers deep, so if we have a call to an unknown function, we have to take the first ~ 3 calls/jmps from that function's body and do the same recursive check on each of those functions.

Open Questions:

• Is this useful enough to justify the work involved?
• Is this useful enough to justify adding more attributes for the user to scroll past?
• Should the constructor parameter types also be specified?

References: https://github.com/SamboyCoding/Cpp2IL/blob/new-analysis/Cpp2IL.Core/Analysis/Actions/x86/Important/CallExceptionThrowerFunction.cs

[ds5678]

With native method detection implemented, I no longer see much justification for this feature. The constructor calls show up clearly in the analysis, even if some traversal is required.