From 62387a0e326460e3dd1fcd7bda4f7b85506b78b4 Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Thu, 25 Nov 2021 08:03:27 -0500
Subject: [PATCH] Fix display of empty string constant (#3207) (#3215).

---
 Changes                        |  2 +-
 src/V3Width.cpp                | 10 +++++++++-
 test_regress/t/t_string_size.v | 19 +++++++++++++++++++
 3 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/Changes b/Changes
index 10f50d405..ba85d7c42 100644
--- a/Changes
+++ b/Changes
@@ -24,7 +24,7 @@ Verilator 4.215 devel
 * Fix nested generate if genblk naming (#3189). [yanx21]
 * Fix hang on recursive definition error (#3199). [Jonathan Kimmitt]
 * Fix display of signed without format (#3204). [Julie Schwartz]
-* Fix display of empty string constant (#3207). [Julie Schwartz]
+* Fix display of empty string constant (#3207) (#3215). [Julie Schwartz]
 * Fix incorrect width after and-or optimization (#3208). [Julie Schwartz]
 * Fix $fopen etc on integer arrays (#3214). [adrienlemasle]
 * Fix $size on dynamic strings (#3216).
diff --git a/src/V3Width.cpp b/src/V3Width.cpp
index 15df19767..284eeab1e 100644
--- a/src/V3Width.cpp
+++ b/src/V3Width.cpp
@@ -1939,7 +1939,15 @@ private:
                     } else {
                         issigned = bdtypep->isSigned();
                     }
-                    if (nodep->valuep()->dtypep()->widthSized()) {
+                    if (valueBdtypep->isString()) {
+                        // parameter X = "str", per IEEE is a number, not a string
+                        if (const auto* const constp = VN_CAST(nodep->valuep(), Const)) {
+                            if (constp->num().isString()) {
+                                width = constp->num().toString().length() * 8;
+                            }
+                        }
+                        if (width < 8) width = 8;
+                    } else if (nodep->valuep()->dtypep()->widthSized()) {
                         width = nodep->valuep()->width();
                     } else {
                         if (nodep->valuep()->width() > 32) {
diff --git a/test_regress/t/t_string_size.v b/test_regress/t/t_string_size.v
index f9d87caa3..b18b92137 100644
--- a/test_regress/t/t_string_size.v
+++ b/test_regress/t/t_string_size.v
@@ -10,6 +10,11 @@ module t;
    parameter string OS = "O";
    parameter OI = "O";  // B is an integer of width 8
 
+   parameter bit [31:0] NEST = "NEST";
+   parameter bit [31:0] TEST = "TEST";
+   bit [31:0] rest;
+   string s;
+
    initial begin
       $display(">< == >%s<", "");
       $display(">< == >%s<", ES);
@@ -18,9 +23,23 @@ module t;
       if ($bits("") != 0) $stop;
       if ($bits("A") != 8) $stop;
       if ($bits(ES) != 0) $stop;
+      if ($bits(EI) != 8) $stop;
       if ($bits(OS) != 8) $stop;
       if ($bits(OI) != 8) $stop;
 
+      if (ES == "TEST") $stop;  // Illegal in some simulators as not both strings
+      if (EI == "TEST") $stop;
+      if (OS == "TEST") $stop;  // Illegal in some simulators as not both strings
+      // verilator lint_off WIDTH
+      if (OI == "TEST") $stop;
+      if (rest == "TEST") $stop;
+
+      if (ES == TEST) $stop;
+      if (EI == TEST) $stop;
+      if (OS == TEST) $stop;
+      if (OI == TEST) $stop;
+      if (rest == TEST) $stop;
+
       $write("*-* All Finished *-*\n");
       $finish;
    end