From d5b9c1da5957eb3960fcefd6083d116b7a4086c0 Mon Sep 17 00:00:00 2001
From: Zachary Snow <zach@zachjs.com>
Date: Sat, 4 Nov 2023 11:36:08 -0400
Subject: [PATCH] visit function args in empty args conversion

---
 CHANGELOG.md             | 1 +
 src/Convert/EmptyArgs.hs | 3 ++-
 test/core/empty_args.sv  | 5 +++++
 test/core/empty_args.v   | 5 +++++
 4 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7dcf1561..4eccf09e 100644
--- a/CHANGELOG.md
+++ b/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
 
diff --git a/src/Convert/EmptyArgs.hs b/src/Convert/EmptyArgs.hs
index 4290e61d..51d4e892 100644
--- a/src/Convert/EmptyArgs.hs
+++ b/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' [])
diff --git a/test/core/empty_args.sv b/test/core/empty_args.sv
index 35bc3e16..32b0d33b 100644
--- a/test/core/empty_args.sv
+++ b/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
diff --git a/test/core/empty_args.v b/test/core/empty_args.v
index b7a22e0f..1adaec17 100644
--- a/test/core/empty_args.v
+++ b/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