A few VCD trace changes

interface/vsrtl_interface.h

@@ -712,14 +712,15 @@ class SimDesign : public SimComponent {
  long long getCycleCount() const { return m_cycleCount; }
 
  /**
- * @brief vcdDump
- * @param enabled; enables dumping of all ports to a vcd file. For each port
- * in the circuit, we connect an additional slot which will queue a notice to
- * this top-level Design that the variable change is to be written to the VCD
- * file.
+ * @brief vcdTrace
+ * @param enabled; enables dumping of all ports to a vcd file. For each
+ * port in the circuit, we connect an additional slot which will queue a
+ * notice to this top-level Design that the variable change is to be
+ * written to the VCD file.
  */
- void vcdDump(bool enabled) {
+ void vcdTrace(bool enabled, const std::string &filename = "") {
  m_dumpVcdFiles = enabled;
+ m_vcdFileName = filename.empty() ? getName() + ".vcd" : filename;
  std::map<SimComponent *, std::vector<SimComponent *>> componentGraph;
  getComponentGraph(componentGraph);
  for (const auto &compIt : componentGraph) {
@@ -745,7 +746,7 @@ class SimDesign : public SimComponent {
  * wherein they reside.
  */
  void resetVcdFile() {
- m_vcdFile = std::make_unique<VCDFile>(getName() + ".vcd");
+ m_vcdFile = std::make_unique<VCDFile>(m_vcdFileName);
  {
  auto def1 = m_vcdFile->writeHeader();
  auto def2 = m_vcdFile->scopeDef("TOP");
@@ -819,6 +820,7 @@ class SimDesign : public SimComponent {
  std::set<const SimPort *> m_vcdVarChangeQueue;
  std::string m_vcdClkId;
  bool m_dumpVcdFiles = false;
+ std::string m_vcdFileName;
 
 #ifndef NDEBUG
  long long m_cycleCountPre = 0;

interface/vsrtl_vcdfile.cpp

@@ -23,16 +23,18 @@ std::string binStr(T val, unsigned width) {
  return s;
 }
 
-VCDFile::VCDFile(const std::string &filename) {
- m_file.open(filename, std::ios_base::trunc);
+VCDFile::VCDFile(const std::string &filename) { m_filename = filename; }
+
+void VCDFile::ensureOpen() {
+ if (m_file.is_open())
+ return;
+ m_file.open(m_filename, std::ios_base::trunc);
 }
 
 VCDFile::~VCDFile() { m_file.close(); }
 
 void VCDFile::writeLine(const std::string &line) {
- if (!m_file.is_open()) {
- throw std::runtime_error("Tried to write to file, but file was not open");
- }
+ ensureOpen();
  const std::string indent = std::string(m_scopeLevel * 4, ' ');
  m_file << indent << line + "\n";
 };

interface/vsrtl_vcdfile.h

@@ -36,12 +36,15 @@ class VCDFile {
  }
 
 private:
+ // Ensures that the file is opened and ready for writing.
+ void ensureOpen();
  std::string genId();
  void writeLine(const std::string &line);
  std::ofstream m_file;
  std::map<std::string, unsigned> m_varWidths;
  std::map<std::string, uint64_t> m_dumpVars;
 
+ std::string m_filename;
  unsigned m_varCntr = 0;
  unsigned m_scopeLevel = 0;
 };