Merge pull request #138 from JuliaDebug/teh/union

Don't try to call `nameof` on Unions

Author: timholy

src/construct.jl

@@ -206,8 +206,7 @@ function prepare_call(@nospecialize(f), allargs; enter_generated = false)
     # Can happen for thunks created by generated functions
     if isa(f, Core.Builtin) || isa(f, Core.IntrinsicFunction)
         return nothing
-    elseif any(x -> isa(x, Type) &&
-                    (x <: Vararg || (typeof(x) in (UnionAll, DataType) && nameof(x) == :Vararg)), allargs)
+    elseif any(is_vararg_type, allargs)
         return nothing  # https://github.com/JuliaLang/julia/issues/30995
     end
     argtypes = Tuple{map(_Typeof,allargs)...}

src/utils.jl

@@ -131,6 +131,17 @@ end
 
 is_leaf(frame::Frame) = frame.callee === nothing
 
+function is_vararg_type(x)
+    if isa(x, Type)
+        x <: Vararg && return true
+        if isa(x, UnionAll)
+            x = Base.unwrap_unionall(x)
+        end
+        return isa(x, DataType) && nameof(x) == :Vararg
+    end
+    return false
+end
+
 ## Location info
 
 function lineoffset(framecode::FrameCode)

test/interpret.jl

@@ -379,4 +379,8 @@ end
     buf = IOBuffer()
     me = Base.MethodError(method_c1,(1, 1, ""))
     @test (@interpret Base.show_method_candidates(buf, me)) == nothing
+
+    varargidentity(x) = x
+    x = Union{Array{UInt8,N},Array{Int8,N}} where N
+    @test isa(JuliaInterpreter.prepare_call(varargidentity, [varargidentity, x])[1], JuliaInterpreter.FrameCode)
 end