visit function args in empty args conversion

CHANGELOG.md

@@ -18,6 +18,7 @@
 * Fixed failure to resolve typenames suffixed with dimensions in contexts
   permitting both types and expressions, e.g., `$bits(T[W-1:0])`
 * Fixed errant constant folding of shadowed non-trivial localparams
+* Fixed conversion of function calls with no arguments passed to other functions
 * Fixed certain non-ANSI style port declarations being incorrectly reported as
   incompatible
 

src/Convert/EmptyArgs.hs

@@ -64,7 +64,8 @@ traverseStmt = traverseStmtExprsM traverseExpr
 traverseExpr :: Expr -> SC Expr
 traverseExpr (Call func (Args args [])) = do
     details <- lookupElemM $ Dot func dummyIdent
-    let args' = if details /= Nothing
+    args' <- mapM traverseExpr $
+                if details /= Nothing
                     then RawNum 0 : args
                     else args
     return $ Call func (Args args' [])

test/core/empty_args.sv

@@ -3,4 +3,9 @@ module top;
         return 32'h00000013;
     endfunction
     initial $display(nop());
+    function automatic integer flip;
+        input integer inp;
+        return ~inp;
+    endfunction
+    initial $display(flip(nop()));
 endmodule

test/core/empty_args.v

@@ -4,4 +4,9 @@ module top;
         nop = 32'h00000013;
     endfunction
     initial $display(nop(0));
+    function automatic integer flip;
+        input integer inp;
+        flip = ~inp;
+    endfunction
+    initial $display(flip(nop(0)));
 endmodule