fix typeof incorrectly propagating implicit types

src/Convert/TypeOf.hs

@@ -41,9 +41,10 @@ traverseDeclM decl = do
     item <- traverseModuleItemM (MIPackageItem $ Decl decl)
     let MIPackageItem (Decl decl') = item
     case decl' of
-        Variable Local UnknownType ident [] Nil -> do
-            -- functions with no return type implicitly return a single bit
-            insertElem ident UnitType
+        Variable Local (Implicit sg rs) ident [] Nil -> do
+            -- implicit types, which are commonly found in function return
+            -- types, are recast as logics to avoid outputting bare ranges
+            insertElem ident $ IntegerVector TLogic sg rs
             return decl'
         Variable d t ident a e -> do
             let t' = injectRanges t a

test/basic/case_inside_cast.sv

@@ -0,0 +1,17 @@
+module top;
+    typedef logic [1:0] T;
+    function automatic [1:0] flip;
+        input [1:0] inp;
+        flip = ~inp;
+    endfunction
+    initial begin
+        case (flip(2'b00)) inside
+            2'b11: $display("good");
+            default: $display("default");
+        endcase
+        case (T'(flip(2'b00))) inside
+            2'b11: $display("good");
+            default: $display("default");
+        endcase
+    end
+endmodule

test/basic/case_inside_cast.v

@@ -0,0 +1,6 @@
+module top;
+    initial begin
+        $display("good");
+        $display("good");
+    end
+endmodule