fix: missing scalar indexing check for setindex

src/Enzyme.jl

@@ -0,0 +1,7 @@
+# TODO: move the overload_autodiff here as well
+
+# The default `onehot` will lead to scalar indexing
+function Enzyme.onehot(x::TracedRArray{T,N}) where {T,N}
+    x_arr = zeros(T, size(x))
+    return map(Base.Fix1(TracedUtils.promote_to, TracedRArray{T,N}), Enzyme.onehot(x_arr))
+end

src/Reactant.jl

@@ -203,6 +203,9 @@ end
 include("stdlibs/LinearAlgebra.jl")
 include("stdlibs/Random.jl")
 
+# Other Integrations
+include("Enzyme.jl")
+
 const TracedType = Union{TracedRArray,TracedRNumber,MissingTracedValue}
 
 include("ControlFlow.jl")

src/TracedRArray.jl

@@ -172,7 +172,17 @@ function Base.getindex(a::WrappedTracedRArray, indices...)
     return getindex(ancestor(a), TracedUtils.get_ancestor_indices(a, indices...)...)
 end
 
+function maybe_assert_scalar_setindexing(
+    ::TracedRArray{T,N}, ::Vararg{Union{Int,TracedRNumber{Int}},N}
+) where {T,N}
+    return GPUArraysCore.assertscalar("setindex!(::TracedRArray, v, ::Vararg{Int, N})")
+end
+
+maybe_assert_scalar_setindexing(args...) = nothing
+
 function Base.setindex!(a::TracedRArray{T,N}, v, indices::Vararg{Any,N}) where {T,N}
+    maybe_assert_scalar_setindexing(a, indices...)
+
     indices = map(enumerate(indices)) do (idx, i)
         i isa Colon && return 1:size(a, idx)
         i isa CartesianIndex && return Tuple(i)
@@ -473,6 +483,10 @@ function Base.copyto!(dest::TracedRArray{T,N}, src::TracedRArray{T,N}) where {T,
     return dest
 end
 
+function Base.copyto!(dest::TracedRArray{T,N}, src::TracedRArray{T2,N}) where {T,T2,N}
+    return copyto!(dest, Ops.convert(TracedRArray{T,N}, src))
+end
+
 function _copyto!(dest::AnyTracedRArray, bc::Broadcasted)
     axes(dest) == axes(bc) || Broadcast.throwdm(axes(dest), axes(bc))
     isempty(dest) && return dest

test/control_flow.jl

@@ -355,7 +355,7 @@ function condition10_condition_with_setindex(x)
     @trace if sum(x) > 0
         x[:, 1] = -1.0
     else
-        x[1, 1] = 1.0
+        @allowscalar x[1, 1] = 1.0
     end
     return x
 end
@@ -457,7 +457,7 @@ end
 
 function for_with_step(x)
     @trace for i in 10:3:22
-        x[i] = i * i
+        @allowscalar x[i] = i * i
     end
     return x
 end
@@ -539,7 +539,7 @@ function cumsum!(x)
     v = zero(eltype(x))
     @trace for i in 1:length(x)
         v += @allowscalar x[i]
-        x[i] = v
+        @allowscalar x[i] = v
     end
     return x
 end