add bounds check to Slices indexing (#47622)

Co-authored-by: Simon Byrne <[email protected]>

Author: mcabbott

base/slicearray.jl

@@ -85,7 +85,7 @@ the ordering of the dimensions will match those in `dims`. If `drop = false`, th
 `Slices` will have the same dimensionality as the underlying array, with inner
 dimensions having size 1.
 
-See [`stack`](@ref)`(slices; dims)` for the inverse of `eachcol(A; dims::Integer, drop=true)`.
+See [`stack`](@ref)`(slices; dims)` for the inverse of `eachslice(A; dims::Integer)`.
 
 See also [`eachrow`](@ref), [`eachcol`](@ref), [`mapslices`](@ref) and [`selectdim`](@ref).
 
@@ -232,9 +232,13 @@ size(s::Slices) = map(length, s.axes)
     return map(l -> l === (:) ? (:) : c[l], s.slicemap)
 end
 
-Base.@propagate_inbounds getindex(s::Slices{P,SM,AX,S,N}, I::Vararg{Int,N}) where {P,SM,AX,S,N} =
-    view(s.parent, _slice_index(s, I...)...)
-Base.@propagate_inbounds setindex!(s::Slices{P,SM,AX,S,N}, val, I::Vararg{Int,N}) where {P,SM,AX,S,N} =
-    s.parent[_slice_index(s, I...)...] = val
+@inline function getindex(s::Slices{P,SM,AX,S,N}, I::Vararg{Int,N}) where {P,SM,AX,S,N}
+    @boundscheck checkbounds(s, I...)
+    @inbounds view(s.parent, _slice_index(s, I...)...)
+end
+@inline function setindex!(s::Slices{P,SM,AX,S,N}, val, I::Vararg{Int,N}) where {P,SM,AX,S,N}
+    @boundscheck checkbounds(s, I...)
+    @inbounds s.parent[_slice_index(s, I...)...] = val
+end
 
 parent(s::Slices) = s.parent

test/arrayops.jl

@@ -2293,6 +2293,15 @@ end
         f2(a) = eachslice(a, dims=2)
         @test (@inferred f2(a)) == eachcol(a)
     end
+
+    @testset "eachslice bounds checking" begin
+        # https://github.com/JuliaLang/julia/pull/32310#issuecomment-1146911510
+        A = eachslice(rand(2,3), dims = 2, drop = false)
+        @test_throws BoundsError A[2, 1]
+        @test_throws BoundsError A[4]
+        @test_throws BoundsError A[2,3] = [4,5]
+        @test_throws BoundsError A[2,3] .= [4,5]
+    end
 end
 
 ###