Rename tracing rolloverSize and add test (#3570).

Changes

@@ -22,6 +22,7 @@ Verilator 4.225 devel
 * Fix segfault exporting non-existant package (#3535).
 * Fix case statement comparing string literal (#3544). [Gustav Svensk]
 * Improve Verilation speed with --threads on large designs. [Geza Lore]
+* Rename trace rolloverSize() (#3570).
 
 
 Verilator 4.224 2022-06-19

include/verilated_vcd_c.cpp

@@ -120,13 +120,13 @@ void VerilatedVcd::open(const char* filename) VL_MT_SAFE_EXCLUDES(m_mutex) {
     // Set member variables
     m_filename = filename;  // "" is ok, as someone may overload open
 
-    openNextImp(m_rolloverMB != 0);
+    openNextImp(m_rolloverSize != 0);
     if (!isOpen()) return;
 
     dumpHeader();
 
     // When using rollover, the first chunk contains the header only.
-    if (m_rolloverMB) openNextImp(true);
+    if (m_rolloverSize) openNextImp(true);
 }
 
 void VerilatedVcd::openNext(bool incFilename) VL_MT_SAFE_EXCLUDES(m_mutex) {
@@ -180,7 +180,7 @@ void VerilatedVcd::openNextImp(bool incFilename) {
 }
 
 bool VerilatedVcd::preChangeDump() {
-    if (VL_UNLIKELY(m_rolloverMB && m_wroteBytes > m_rolloverMB)) openNextImp(true);
+    if (VL_UNLIKELY(m_rolloverSize && m_wroteBytes > m_rolloverSize)) openNextImp(true);
     return isOpen();
 }
 

include/verilated_vcd_c.h

@@ -50,7 +50,7 @@ private:
     bool m_fileNewed;  // m_filep needs destruction
     bool m_isOpen = false;  // True indicates open file
     std::string m_filename;  // Filename we're writing to (if open)
-    uint64_t m_rolloverMB = 0;  // MB of file size to rollover at
+    uint64_t m_rolloverSize = 0;  // File size to rollover at
     int m_modDepth = 0;  // Depth of module hierarchy
 
     char* m_wrBufp;  // Output buffer
@@ -124,8 +124,8 @@ public:
     ~VerilatedVcd();
 
     // ACCESSORS
-    // Set size in megabytes after which new file should be created
-    void rolloverMB(uint64_t rolloverMB) { m_rolloverMB = rolloverMB; }
+    // Set size in bytes after which new file should be created.
+    void rolloverSize(uint64_t size) { m_rolloverSize = size; }
 
     // METHODS - All must be thread safe
     // Open the file; call isOpen() to see if errors
@@ -271,8 +271,12 @@ public:
     /// The header is only in the first file created, this allows
     /// "cat" to be used to combine the header plus any number of data files.
     void openNext(bool incFilename = true) VL_MT_SAFE { m_sptrace.openNext(incFilename); }
-    /// Set size in megabytes after which new file should be created
-    void rolloverMB(size_t rolloverMB) VL_MT_SAFE { m_sptrace.rolloverMB(rolloverMB); }
+    /// Set size in bytes after which new file should be created
+    /// This will create a header file, followed by each separate file
+    /// which might be larger than the given size (due to chunking and
+    /// alignment to a start of a given time's dump).  Any file but the
+    /// first may be removed.  Cat files together to create viewable vcd.
+    void rolloverSize(size_t size) VL_MT_SAFE { m_sptrace.rolloverSize(size); }
     /// Close dump
     void close() VL_MT_SAFE { m_sptrace.close(); }
     /// Flush dump

test_regress/t/t_trace_rollover.cpp

@@ -0,0 +1,45 @@
+// -*- mode: C++; c-file-style: "cc-mode" -*-
+//
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2008 by Wilson Snyder.
+// SPDX-License-Identifier: CC0-1.0
+
+#include <verilated.h>
+#include <verilated_vcd_c.h>
+
+#include <memory>
+
+#include VM_PREFIX_INCLUDE
+
+unsigned long long main_time = 0;
+double sc_time_stamp() { return (double)main_time; }
+
+int main(int argc, char** argv, char** env) {
+    std::unique_ptr<VM_PREFIX> top{new VM_PREFIX("top")};
+
+    Verilated::debug(0);
+    Verilated::traceEverOn(true);
+
+    std::unique_ptr<VerilatedVcdC> tfp{new VerilatedVcdC};
+    top->trace(tfp.get(), 99);
+
+    tfp->rolloverSize(1000);  // But will be increased to 8kb chunk size
+    tfp->open(VL_STRINGIFY(TEST_OBJ_DIR) "/simrollover.vcd");
+
+    top->clk = 0;
+
+    while (main_time < 1900) {  // Creates 2 files
+        top->clk = !top->clk;
+        top->eval();
+        tfp->dump((unsigned int)(main_time));
+        ++main_time;
+    }
+    tfp->close();
+    top->final();
+    tfp.reset();
+    top.reset();
+    printf("*-* All Finished *-*\n");
+    return 0;
+}

test_regress/t/t_trace_rollover.pl

@@ -0,0 +1,36 @@
+#!/usr/bin/env perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003-2013 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);
+
+top_filename("t_trace_cat.v");
+
+compile(
+    make_top_shell => 0,
+    make_main => 0,
+    v_flags2 => ["--trace --exe $Self->{t_dir}/t_trace_rollover.cpp"],
+    );
+
+execute(
+    check_finished => 1,
+    );
+
+system("cat $Self->{obj_dir}/simrollover_cat*.vcd "
+       . " > $Self->{obj_dir}/simall.vcd");
+
+vcd_identical("$Self->{obj_dir}/simall.vcd",
+              $Self->{golden_filename});
+
+file_grep_not("$Self->{obj_dir}/simrollover_cat0000.vcd", qr/^#/i);
+file_grep("$Self->{obj_dir}/simrollover_cat0001.vcd", qr/^#/i);
+file_grep("$Self->{obj_dir}/simrollover_cat0002.vcd", qr/^#/i);
+
+ok(1);
+1;