Bug in set_max_fn_args

[wsmoses]

using Enzyme
using LinearAlgebra
using SparseArrays
using Test

Enzyme.API.printall!(true)
Enzyme.API.printactivity!(true)

# Wrapper similar to EnzymeTestUtils
@inline function call_wrapped(f::FT, args...) where FT
    @inline f(args...)
    return nothing
end

for N in 1:5
    argexprs = [Symbol(:arg, Symbol(i)) for i in 1:N]
    eval(quote
        function call_wrapped(f::FT, $(argexprs...)) where {FT}
            Base.@_inline_meta
           @inline f($(argexprs...))
        end
    end)
end

# Enzyme.Compiler.set_fn_max_args(call_wrapped)

function run_autodiff_test()
    Ts = ComplexF64
    M0 = [
        0.0   1.50614;
        0.0  -0.988357;
        0.0   0.0
    ]
    M = SparseMatrixCSC((M0 .+ 2im * M0))
    v = rand(Ts, 2)
    α = rand(Ts)
    β = rand(Ts)
    C = zeros(Ts, size(M, 1))

    # Activities
    dC = zeros(Ts, size(C))
    act_C = Duplicated(copy(C), dC)

    act_M = Const(M)

    dv = zeros(Ts, size(v))
    act_v = Duplicated(copy(v), dv)

    act_α = Active(α)
    act_β = Active(β)

    println("Running autodiff with wrapper...")

    try
        # Using Duplicated as the return activity to match thunk case
        # Note: autodiff signature: (mode, f, return_activity_type, args...)
        Enzyme.autodiff(Reverse, call_wrapped, Const, Const(mul!), act_C, act_M, act_v, Const(1.0), act_β)
        println("Success with wrapped autodiff!")
    catch e
        showerror(stdout, e)
        println()
    end
end

run_autodiff_test()

on 1.12, using EnzymeAD/Enzyme#2684

this passes with the macro expand stuff, but fails when using set_fn_max_args

@gbaraldi @oscardssmith