MemoryRef layout fix (#2746)

* MemoryRef layout fix

* for debug info

* fix

* dbg

* fix

* more fix

* fix

Author: wsmoses

src/typetree.jl

@@ -305,7 +305,7 @@ else
         dl,
         seen::TypeTreeTable,
     ) where {kind,T}
-        tt = copy(typetree(Ptr{T}, ctx, dl, seen))
+        tt = copy(typetree(typed_fieldtype(AT, 1), ctx, dl, seen))
         shift!(tt, dl, 0, sizeof(Int), 0)
 
         for f = 2:fieldcount(AT)

src/utils.jl

@@ -462,10 +462,23 @@ end
 
 else
 
+function is_memory_ref_field2_an_offset(@nospecialize(T::Type{<:GenericMemoryRef}))
+    ET = eltype(T)
+
+    # 0 = inlinealloc
+    # 1 = isboxed
+    # 2 = isbitsunion
+    return (Base.datatype_arrayelem(T.types[2]) == 2) || Base.datatype_layoutsize(T.types[2]) == 0
+end
+
 @inline function typed_fieldtype(@nospecialize(T::Type), i::Int)::Type
     if T <: GenericMemoryRef && i == 1 || T <: GenericMemory && i == 2
-        eT = eltype(T)
-        Ptr{eT}
+        if T <: GenericMemoryRef && i == 1 && is_memory_ref_field2_an_offset(T)
+            Int
+        else
+            eT = eltype(T)
+            Ptr{eT}
+        end
     else
         fieldtype(T, i)
     end

test/typetree.jl

@@ -48,6 +48,9 @@ struct UnionStruct1{T}
     y::Any
 end
 
+struct EmptyStruct
+end
+
 @testset "TypeTree" begin
     @test tt(Float16) == "{[-1]:Float@half}"
     @test tt(Float32) == "{[-1]:Float@float}"
@@ -99,6 +102,14 @@ end
               "{[0]:Pointer, [0,0]:Pointer, [0,4]:Float@float, [0,8]:Float@double, [4]:Integer, [8]:Pointer, [8,0]:Pointer, [8,4]:Float@float, [8,8]:Float@double, [12]:Integer, [16]:Pointer, [16,0]:Pointer, [16,4]:Float@float, [16,8]:Float@double, [20]:Integer, [24]:Pointer, [24,0]:Pointer, [24,4]:Float@float, [24,8]:Float@double}"
     end
 
+    @static if VERSION >= v"1.11-"
+        if Sys.WORD_SIZE == 64
+            @test tt(MemoryRef{EmptyStruct}) == "{[0]:Integer, [1]:Integer, [2]:Integer, [3]:Integer, [4]:Integer, [5]:Integer, [6]:Integer, [7]:Integer, [8]:Pointer, [8,0]:Integer, [8,1]:Integer, [8,2]:Integer, [8,3]:Integer, [8,4]:Integer, [8,5]:Integer, [8,6]:Integer, [8,7]:Integer, [8,8]:Pointer}"
+            @test tt(MemoryRef{Union{Float64, Int64}}) == "{[0]:Integer, [1]:Integer, [2]:Integer, [3]:Integer, [4]:Integer, [5]:Integer, [6]:Integer, [7]:Integer, [8]:Pointer, [8,0]:Integer, [8,1]:Integer, [8,2]:Integer, [8,3]:Integer, [8,4]:Integer, [8,5]:Integer, [8,6]:Integer, [8,7]:Integer, [8,8]:Pointer}"
+            @test tt(MemoryRef{Float64}) == "{[-1]:Pointer, [0,-1]:Float@double, [8,0]:Integer, [8,1]:Integer, [8,2]:Integer, [8,3]:Integer, [8,4]:Integer, [8,5]:Integer, [8,6]:Integer, [8,7]:Integer, [8,8]:Pointer, [8,8,-1]:Float@double}"
+        end
+    end
+
     @test tt(UnionStruct1{Float32}) == "{[0]:Float@float, [4]:Integer, [8]:Pointer}"
 
     if Sys.WORD_SIZE == 64