Fixes for opaque closure method lowering (#34)

opaque_closure_method has special non-evaluated semantics for its
argument list, so we need some special non-quoted conversion here for
the functionloc argument and the name argument when it's set to
the global ref Core.nothing.

To fix the globalref, I've chosen to translate `"core"::K"nothing"` into
a literal `nothing` in general - this is consistent with how ast.c
translates the special flisp `(null)` form.

Author: c42f

src/eval.jl

@@ -232,6 +232,10 @@ function to_lowered_expr(mod, ex, ssa_offset=0)
         if name == "cglobal"
             # cglobal isn't a true name within core - instead it's a builtin
             :cglobal
+        elseif name == "nothing"
+            # Translate Core.nothing into literal `nothing`s (flisp uses a
+            # special form (null) for this during desugaring, etc)
+            nothing
         else
             GlobalRef(Core, Symbol(name))
         end
@@ -286,9 +290,13 @@ function to_lowered_expr(mod, ex, ssa_offset=0)
         Expr(:method, c1, cs[2:end]...)
     elseif k == K"newvar"
         Core.NewvarNode(to_lowered_expr(mod, ex[1], ssa_offset))
-    elseif k == K"new_opaque_closure"
+    elseif k == K"opaque_closure_method"
         args = map(e->to_lowered_expr(mod, e, ssa_offset), children(ex))
-        Expr(:new_opaque_closure, args...)
+        # opaque_closure_method has special non-evaluated semantics for the
+        # `functionloc` line number node so we need to undo a level of quoting
+        @assert args[4] isa QuoteNode
+        args[4] = args[4].value
+        Expr(:opaque_closure_method, args...)
     elseif k == K"meta"
         args = Any[to_lowered_expr(mod, e, ssa_offset) for e in children(ex)]
         # Unpack K"Symbol" QuoteNode as `Expr(:meta)` requires an identifier here.
@@ -317,7 +325,7 @@ function to_lowered_expr(mod, ex, ssa_offset=0)
                k == K"gc_preserve_end"   ? :gc_preserve_end   :
                k == K"foreigncall"       ? :foreigncall       :
                k == K"cfunction"         ? :cfunction         :
-               k == K"opaque_closure_method" ? :opaque_closure_method :
+               k == K"new_opaque_closure" ? :new_opaque_closure :
                nothing
         if isnothing(head)
             throw(LoweringError(ex, "Unhandled form for kind $k"))

test/closures.jl

@@ -235,4 +235,10 @@ let
 end
 """) == (3,4,5)
 
+# opaque_closure_method internals
+method_ex = lower_str(test_mod, "Base.Experimental.@opaque x -> 2x").args[1].code[3]
+@test method_ex.head === :opaque_closure_method
+@test method_ex.args[1] === nothing
+@test method_ex.args[4] isa LineNumberNode
+
 end

test/misc.jl

@@ -47,11 +47,8 @@ cf_float = JuliaLowering.include_string(test_mod, """
 @test @ccall($cf_float(2::Float64, 3::Float64)::Float64) == 32.0
 
 @testset "CodeInfo: has_image_globalref" begin
-    elower(mod, s) = JuliaLowering.to_lowered_expr(
-        mod, JuliaLowering.lower(
-            mod, parsestmt(JuliaLowering.SyntaxTree, s)))
-    @test elower(test_mod, "x + y").args[1].has_image_globalref === false
-    @test elower(Main, "x + y").args[1].has_image_globalref === true
+    @test lower_str(test_mod, "x + y").args[1].has_image_globalref === false
+    @test lower_str(Main, "x + y").args[1].has_image_globalref === true
 end
 
 end

test/utils.jl

@@ -262,6 +262,11 @@ function watch_ir_tests(dir, delay=0.5)
     end
 end
 
+function lower_str(mod, s)
+    ex = parsestmt(JuliaLowering.SyntaxTree, s)
+    return JuliaLowering.to_lowered_expr(mod, JuliaLowering.lower(mod, ex))
+end
+
 # See Julia Base tests in "test/docs.jl"
 function docstrings_equal(d1, d2; debug=true)
     io1 = IOBuffer()