Remove deprecated and unused timescale override defines

These have been 'deprecated' for 2 years and are otherwise unused except
for using a temporary placeholder value, which I have inlined with the
default value.

Also remove the now VL_TIME_STR_CONVERT utility function (and
corresponding unit tests), which have no references in any project on
GitHub.

include/verilated.cpp

@@ -2164,29 +2164,6 @@ void VL_WRITEMEM_N(bool hex,  // Hex format, else binary
 //===========================================================================
 // Timescale conversion
 
-// Helper function for conversion of timescale strings
-// Converts (1|10|100)(s|ms|us|ns|ps|fs) to power of then
-int VL_TIME_STR_CONVERT(const char* strp) VL_PURE {
-    int scale = 0;
-    if (!strp) return 0;
-    if (*strp++ != '1') return 0;
-    while (*strp == '0') {
-        ++scale;
-        ++strp;
-    }
-    switch (*strp++) {
-    case 's': break;
-    case 'm': scale -= 3; break;
-    case 'u': scale -= 6; break;
-    case 'n': scale -= 9; break;
-    case 'p': scale -= 12; break;
-    case 'f': scale -= 15; break;
-    default: return 0;
-    }
-    if ((scale < 0) && (*strp++ != 's')) return 0;
-    if (*strp) return 0;
-    return scale;
-}
 static const char* vl_time_str(int scale) VL_PURE {
     static const char* const names[]
         = {"100s",  "10s",  "1s",  "100ms", "10ms", "1ms", "100us", "10us", "1us",
@@ -2308,8 +2285,9 @@ void VerilatedContext::checkMagic(const VerilatedContext* contextp) {
 }
 
 VerilatedContext::Serialized::Serialized() {
-    m_timeunit = VL_TIME_UNIT;  // Initial value until overriden by _Vconfigure
-    m_timeprecision = VL_TIME_PRECISION;  // Initial value until overriden by _Vconfigure
+    constexpr int8_t picosecond = -12;
+    m_timeunit = picosecond;  // Initial value until overriden by _Vconfigure
+    m_timeprecision = picosecond;  // Initial value until overriden by _Vconfigure
 }
 
 void VerilatedContext::assertOn(bool flag) VL_MT_SAFE {

include/verilated_funcs.h

@@ -256,25 +256,7 @@ extern void _vl_debug_print_w(int lbits, WDataInP const iwp);
 //=========================================================================
 // Pli macros
 
-extern int VL_TIME_STR_CONVERT(const char* strp) VL_PURE;
-
-// These are deprecated and used only to establish the default precision/units.
-// Use Verilator timescale-override for better control.
 // clang-format off
-#ifndef VL_TIME_PRECISION
-# ifdef VL_TIME_PRECISION_STR
-#  define VL_TIME_PRECISION VL_TIME_STR_CONVERT(VL_STRINGIFY(VL_TIME_PRECISION_STR))
-# else
-#  define VL_TIME_PRECISION (-12)  ///< Timescale default units if not in Verilog - picoseconds
-# endif
-#endif
-#ifndef VL_TIME_UNIT
-# ifdef VL_TIME_UNIT_STR
-#  define VL_TIME_UNIT VL_TIME_STR_CONVERT(VL_STRINGIFY(VL_TIME_PRECISION_STR))
-# else
-#  define VL_TIME_UNIT (-12)  ///< Timescale default units if not in Verilog - picoseconds
-# endif
-#endif
 
 #if defined(SYSTEMC_VERSION)
 /// Return current simulation time

test_regress/t/t_timescale.cpp

@@ -1,54 +0,0 @@
-// -*- mode: C++; c-file-style: "cc-mode" -*-
-// This file ONLY is placed under the Creative Commons Public Domain, for
-// any use, without warranty, 2020 by Wilson Snyder.
-// SPDX-License-Identifier: CC0-1.0
-
-#include <verilated.h>
-
-#include "TestCheck.h"
-
-#include VM_PREFIX_INCLUDE
-
-unsigned long long main_time = 0;
-double sc_time_stamp() { return (double)main_time; }
-
-#include <iostream>
-
-#define FILENM "t_timescale.cpp"
-
-int errors = 0;
-
-int main(int argc, char** argv, char** env) {
-    VM_PREFIX* top = new VM_PREFIX("top");
-
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("100s"), 2);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("10s"), 1);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("1s"), 0);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("100ms"), -1);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("10ms"), -2);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("1ms"), -3);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("100us"), -4);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("10us"), -5);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("1us"), -6);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("100ns"), -7);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("10ns"), -8);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("1ns"), -9);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("100ps"), -10);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("10ps"), -11);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("1ps"), -12);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("100fs"), -13);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("10fs"), -14);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("1fs"), -15);
-
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("1.5s"), 0);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("1s "), 0);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("1ss"), 0);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT("s"), 0);
-    TEST_CHECK_EQ(VL_TIME_STR_CONVERT(0), 0);
-
-    top->final();
-    VL_DO_DANGLING(delete top, top);
-    printf("*-* All Finished *-*\n");
-
-    return errors ? 10 : 0;
-}

test_regress/t/t_timescale.pl

@@ -1,24 +0,0 @@
-#!/usr/bin/env perl
-if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
-# DESCRIPTION: Verilator: Verilog Test driver/expect definition
-#
-# Copyright 2003-2019 by Wilson Snyder. This program is free software; you
-# can redistribute it and/or modify it under the terms of either the GNU
-# Lesser General Public License Version 3 or the Perl Artistic License
-# Version 2.0.
-# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
-
-scenarios(vlt_all => 1);
-
-compile(
-    make_top_shell => 0,
-    make_main => 0,
-    v_flags2 => ["--exe $Self->{t_dir}/t_timescale.cpp"],
-    );
-
-execute(
-    check_finished => 1,
-    );
-
-ok(1);
-1;

test_regress/t/t_timescale.v

@@ -1,3 +0,0 @@
-module t;
-
-endmodule