From c3dd6f5344d69d03be60c3ddd0800bdfe05ade53 Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Sat, 5 Mar 2022 16:19:53 -0500
Subject: [PATCH] Fix public function arguments that are arrayed (#3316).

---
 Changes                        |  1 +
 src/V3AstNodes.cpp             | 42 ++++++++++++++++++++--------------
 test_regress/t/t_func_public.v |  7 ++++++
 3 files changed, 33 insertions(+), 17 deletions(-)

diff --git a/Changes b/Changes
index d6c2cdff4..07c6c9b30 100644
--- a/Changes
+++ b/Changes
@@ -19,6 +19,7 @@ Verilator 4.219 devel
 * Add trace dumpvars() call for selective runtime tracing (#3322). [Shunyao CAD]
 * Fix skipping public enum values with four-state values (#3303).
 * Fix $readmem file not found to be warning not error (#3310). [Alexander Grobman]
+* Fix public function arguments that are arrayed (#3316). [pawel256]
 * Fix compile error with --trace-fst --sc (#3332). [leavinel]
 * Fix crash in recursive module inlining (#3324). [Larry Doolittle]
 
diff --git a/src/V3AstNodes.cpp b/src/V3AstNodes.cpp
index 0ec29945f..4b90ed159 100644
--- a/src/V3AstNodes.cpp
+++ b/src/V3AstNodes.cpp
@@ -454,25 +454,33 @@ string AstVar::cPubArgType(bool named, bool forReturn) const {
     if (forReturn) named = false;
     string arg;
     if (isWide() && isReadOnly()) arg += "const ";
-    if (widthMin() == 1) {
-        arg += "bool";
-    } else if (widthMin() <= VL_IDATASIZE) {
-        arg += "uint32_t";
-    } else if (widthMin() <= VL_QUADSIZE) {
-        arg += "vluint64_t";
-    } else {
-        arg += "uint32_t";  // []'s added later
-    }
-    if (isWide()) {
-        if (forReturn) {
-            v3warn(E_UNSUPPORTED, "Unsupported: Public functions with >64 bit outputs; "
-                                  "make an output of a public task instead");
+    const bool isRef = !forReturn && (isWritable() || direction().isRefOrConstRef());
+    if (VN_IS(dtypeSkipRefp(), BasicDType) && !dtypeSkipRefp()->isDouble()
+        && !dtypeSkipRefp()->isString()) {
+        // Backward compatible type declaration
+        if (widthMin() == 1) {
+            arg += "bool";
+        } else if (widthMin() <= VL_IDATASIZE) {
+            arg += "uint32_t";
+        } else if (widthMin() <= VL_QUADSIZE) {
+            arg += "vluint64_t";
+        } else {
+            arg += "uint32_t";  // []'s added later
+        }
+        if (isWide()) {
+            if (forReturn) {
+                v3warn(E_UNSUPPORTED, "Unsupported: Public functions with >64 bit outputs; "
+                                      "make an output of a public task instead");
+            }
+            arg += " (& " + name();
+            arg += ")[" + cvtToStr(widthWords()) + "]";
+        } else {
+            if (isRef) arg += "&";
+            if (named) arg += " " + name();
         }
-        arg += " (& " + name();
-        arg += ")[" + cvtToStr(widthWords()) + "]";
     } else {
-        if (!forReturn && (isWritable() || direction().isRefOrConstRef())) arg += "&";
-        if (named) arg += " " + name();
+        // Newer internal-compatible types
+        arg += dtypep()->cType((named ? name() : string{}), true, isRef);
     }
     return arg;
 }
diff --git a/test_regress/t/t_func_public.v b/test_regress/t/t_func_public.v
index d97a93b34..00a58e67e 100644
--- a/test_regress/t/t_func_public.v
+++ b/test_regress/t/t_func_public.v
@@ -32,6 +32,13 @@ module t (clk);
       $write("Hello in publicTop\n");
    endtask
 
+   task test_task(input [19:0] in [2], output [19:0] out [2]);
+      // Issue 3316
+      // verilator public
+      out[0] = in[1];
+      out[1] = in[0];
+   endtask
+
 endmodule
 
 module tpub (