Fix core lowering hook for testing purposes (#97)

Also fix a small bug in `_eval` when file is `nothing`

Author: mlechu

src/eval.jl

@@ -475,8 +475,9 @@ function _eval(mod, iter)
             break
         elseif type == :begin_module
             push!(modules, mod)
+            filename = something(thunk[4].file, :none)
             mod = @ccall jl_begin_new_module(mod::Any, thunk[2]::Symbol, thunk[3]::Cint,
-                                             thunk[4].file::Cstring, thunk[4].line::Cint)::Module
+                                             filename::Cstring, thunk[4].line::Cint)::Module
             new_mod = mod
         elseif type == :end_module
             @ccall jl_end_new_module(mod::Module)::Cvoid

src/hooks.jl

@@ -18,6 +18,12 @@ function core_lowering_hook(@nospecialize(code), mod::Module,
     local st0 = nothing
     try
         st0 = code isa Expr ? expr_to_syntaxtree(code, LineNumberNode(line, file)) : code
+        if kind(st0) in KSet"toplevel module"
+            return Core.svec(code)
+        elseif kind(st0) === K"doc" && numchildren(st0) >= 2 && kind(st0[2]) === K"module"
+            # TODO: this ignores module docstrings for now
+            return Core.svec(Expr(st0[2]))
+        end
         ctx1, st1 = expand_forms_1(  mod,  st0, true, world)
         ctx2, st2 = expand_forms_2(  ctx1, st1)
         ctx3, st3 = resolve_scopes(  ctx2, st2)

test/hooks.jl

@@ -46,14 +46,38 @@ const JL = JuliaLowering
             @test isdefined(test_mod.M, :x)
 
             # Tricky cases with symbols
-            out = jeval("""module M
+            out = jeval("""module M2
                 Base.@constprop :aggressive function f(x); x; end
                 const what = ccall(:jl_value_ptr, Ptr{Cvoid}, (Any,), Core.nothing)
             end""")
             @test out isa Module
-            @test isdefined(test_mod, :M)
-            @test isdefined(test_mod.M, :f)
-            @test isdefined(test_mod.M, :what)
+            @test isdefined(test_mod, :M2)
+            @test isdefined(test_mod.M2, :f)
+            @test isdefined(test_mod.M2, :what)
+
+            out = jeval(""" "docstring" module M3 end """)
+            @test out isa Module
+            @test isdefined(test_mod, :M3)
+
+            # Macros may produce toplevel expressions.  Note that julia handles
+            # this case badly (macro expansion replaces M5_inner with a
+            # globalref) and we handle esc(:M5_inner) badly
+            out = jeval("""module M5
+            macro newmod()
+                return quote
+                    let a = 1
+                        $(Expr(:toplevel,
+                               Expr(:module, true, :M5_inner,
+                                    Expr(:block, :(global asdf = 1)))))
+                    end
+                end
+            end
+            @newmod()
+            end""")
+            @test out isa Module
+            @test isdefined(test_mod, :M5)
+            @test isdefined(test_mod.M5, :M5_inner)
+            @test isdefined(test_mod.M5.M5_inner, :asdf)
 
             # TODO: broken, commented to prevent error logging
             # @test jeval("Base.@propagate_inbounds @inline meta_double_quote_issue(x) = x") isa Function