fix for varargs in ccall (#240)

Author: KristofferC

Project.toml

@@ -14,9 +14,10 @@ CodeTracking = "0.3.2, 0.4, 0.5"
 [extras]
 Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"
 Distributed = "8ba89e20-285c-5b6f-9357-94700520ee1b"
-Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 SHA = "ea8e919c-243c-51af-8825-aaa63cd721ce"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+Mmap = "a63ad114-7e13-5084-954f-fe012c677804"
+
 
 [targets]
-test = ["Test", "Distributed", "Random", "Dates", "SHA"]
+test = ["Test", "Distributed", "Dates", "SHA", "Mmap"]

src/optimize.jl

@@ -232,6 +232,10 @@ end
 
 function parametric_type_to_expr(t::Type)
     t isa Core.TypeofBottom && return t
+    t isa UnionAll && (t = t.body)
+    if t <: Vararg 
+        return Expr(:(...), t.parameters[1])
+    end
     return t.hasfreetypevars ? Expr(:curly, t.name.name, ((tv-> tv isa TypeVar ? tv.name : tv).(t.parameters))...) : t
 end
 

test/interpret.jl

@@ -1,6 +1,7 @@
 using JuliaInterpreter
 using JuliaInterpreter: enter_call_expr
 using Test, InteractiveUtils, CodeTracking
+using Mmap
 
 module Isolated end
 
@@ -482,4 +483,20 @@ compiled_calls = names(JuliaInterpreter.CompiledCalls; all=true)
 
 # https://github.com/JuliaDebug/JuliaInterpreter.jl/issues/194
 f() =  Meta.lower(Main, Meta.parse("(a=1,0)"))
-@test @interpret f() == f()
+@test @interpret f() == f()
+
+# Test for vararg ccalls (used by mmap)
+function f_mmap()
+    tmp = tempname()
+    local b_mmap
+    try
+        x = rand(10)
+        write(tmp, x)
+        b_mmap = Mmap.mmap(tmp, Vector{Float64})
+        @test b_mmap == x
+    finally
+        finalize(b_mmap)
+        rm(tmp)
+    end
+end
+@interpret f_mmap()