diff --git a/Makefile.in b/Makefile.in
index dc14bddfd..b805f4886 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -322,12 +322,13 @@ cppcheck: $(CPPCHECK_DEP)
 	$(CPPCHECK) $(CPPCHECK_FLAGS) -DVL_DEBUG=1 -DVL_CPPCHECK=1 -DVL_THREADED=1 $(CPPCHECK_INC) $<
 
 CLANGTIDY = clang-tidy
-CLANGTIDY_FLAGS = -config='' -checks='-fuchsia-*,-cppcoreguidelines-avoid-c-arrays,-cppcoreguidelines-init-variables'
+CLANGTIDY_FLAGS = -config='' \
+	-header-filter='.*' \
+	-checks='-fuchsia-*,-cppcoreguidelines-avoid-c-arrays,-cppcoreguidelines-init-variables,-cppcoreguidelines-avoid-goto,-modernize-avoid-c-arrays,-readability-magic-numbers,-readability-simplify-boolean-expr,-cppcoreguidelines-macro-usage' \
+
 CLANGTIDY_DEP = $(subst .h,.h.tidy,$(CPPCHECK_H)) \
 	$(subst .cpp,.cpp.tidy,$(CPPCHECK_CPP))
 CLANGTIDY_DEFS = -DVL_DEBUG=1 -DVL_THREADED=1 -DVL_CPPCHECK=1
-# cppcoreguidelines-avoid-goto modernize-avoid-c-arrays readability-magic-numbers readability-simplify-boolean-expr
-# cppcoreguidelines-macro-usage
 
 clang-tidy: $(CLANGTIDY_DEP)
 %.cpp.tidy: %.cpp
diff --git a/include/verilated.cpp b/include/verilated.cpp
index be9740700..90b5f46c9 100644
--- a/include/verilated.cpp
+++ b/include/verilated.cpp
@@ -700,7 +700,8 @@ std::string _vl_vsformat_time(char* tmp, T ld, int timeunit, bool left, size_t w
             = VL_EXTEND_WQ(b, 0, tmp2, std::numeric_limits<uint64_t>::max());  // breaks shifted
         if (VL_GT_W(w, integer, max64Bit)) {
             WDataOutP v = VL_ASSIGN_W(b, tmp3, integer);  // breaks fracDigitsPow10
-            VlWide<w> zero, ten;
+            VlWide<w> zero;
+            VlWide<w> ten;
             VL_ZERO_W(b, zero);
             VL_EXTEND_WI(b, 0, ten, 10);
             char buf[128];  // 128B is obviously long enough to represent 128bit integer in decimal
@@ -1850,8 +1851,7 @@ VlReadMem::VlReadMem(bool hex, int bits, const std::string& filename, QData star
     , m_bits{bits}
     , m_filename(filename)  // Need () or GCC 4.8 false warning
     , m_end{end}
-    , m_addr{start}
-    , m_linenum{0} {
+    , m_addr{start} {
     m_fp = std::fopen(filename.c_str(), "r");
     if (VL_UNLIKELY(!m_fp)) {
         // We don't report the Verilog source filename as it slow to have to pass it down
@@ -1985,8 +1985,7 @@ void VlReadMem::setData(void* valuep, const std::string& rhs) {
 
 VlWriteMem::VlWriteMem(bool hex, int bits, const std::string& filename, QData start, QData end)
     : m_hex{hex}
-    , m_bits{bits}
-    , m_addr{0} {
+    , m_bits{bits} {
     if (VL_UNLIKELY(start > end)) {
         VL_FATAL_MT(filename.c_str(), 0, "", "$writemem invalid address range");
         return;
@@ -2311,7 +2310,7 @@ std::string VerilatedContext::dumpfile() const VL_MT_SAFE_EXCLUDES(m_timeDumpMut
     return m_dumpfile;
 }
 std::string VerilatedContext::dumpfileCheck() const VL_MT_SAFE_EXCLUDES(m_timeDumpMutex) {
-    const std::string out = dumpfile();
+    std::string out = dumpfile();
     if (VL_UNLIKELY(out.empty())) {
         VL_PRINTF_MT("%%Warning: $dumpvar ignored as not proceeded by $dumpfile\n");
         return "";
@@ -2809,7 +2808,7 @@ void Verilated::runFlushCallbacks() VL_MT_SAFE {
     // When running internal code coverage (gcc --coverage, as opposed to
     // verilator --coverage), dump coverage data to properly cover failing
     // tests.
-    VL_GCOV_FLUSH();
+    VL_GCOV_DUMP();
 }
 
 void Verilated::addExitCb(VoidPCb cb, void* datap) VL_MT_SAFE {
diff --git a/include/verilated.h b/include/verilated.h
index 8943fc523..bed666c7d 100644
--- a/include/verilated.h
+++ b/include/verilated.h
@@ -558,7 +558,8 @@ public:
     /// releases - contact the authors before production use.
     void scopesDump() const VL_MT_SAFE;
 
-public:  // But for internal use only
+    // METHODS - public but for internal use only
+
     // Internal: access to implementation class
     VerilatedContextImp* impp() { return reinterpret_cast<VerilatedContextImp*>(this); }
     const VerilatedContextImp* impp() const {
@@ -884,7 +885,6 @@ public:
     }
 #endif
 
-public:
     // METHODS - INTERNAL USE ONLY (but public due to what uses it)
     // Internal: Create a new module name by concatenating two strings
     // Returns pointer to thread-local static data (overwritten on next call)
diff --git a/include/verilated_cov.cpp b/include/verilated_cov.cpp
index d6f03a7f8..6c0f72340 100644
--- a/include/verilated_cov.cpp
+++ b/include/verilated_cov.cpp
@@ -205,7 +205,7 @@ private:
         // Forward to . so we have a whole word
         const std::string suffix = *bpost ? std::string{bpost + 1} : "";
 
-        const std::string out = prefix + "*" + suffix;
+        std::string out = prefix + "*" + suffix;
 
         // cout << "\nch pre="<<prefix<<"  s="<<suffix<<"\nch a="<<old<<"\nch b="<<add
         // <<"\ncho="<<out<<endl;
diff --git a/include/verilated_cov.h b/include/verilated_cov.h
index c55d32cd8..d110e91c3 100644
--- a/include/verilated_cov.h
+++ b/include/verilated_cov.h
@@ -120,7 +120,8 @@ public:
     /// Zero coverage points
     void zero() VL_MT_SAFE;
 
-public:  // But Internal use only
+    // METHODS - public but Internal use only
+
     // Insert a coverage item
     // We accept from 1-30 key/value pairs, all as strings.
     // Call _insert1, followed by _insert2 and _insert3
@@ -158,7 +159,7 @@ protected:
     // CONSTRUCTORS
     // Internal: Only made as part of VerilatedCovImp
     VerilatedCovContext() = default;
-    virtual ~VerilatedCovContext() = default;
+    ~VerilatedCovContext() override = default;
 
     // METHODS
     // Internal: access to implementation class
diff --git a/include/verilated_fst_c.cpp b/include/verilated_fst_c.cpp
index 69a71c5d9..ad3de6c26 100644
--- a/include/verilated_fst_c.cpp
+++ b/include/verilated_fst_c.cpp
@@ -92,8 +92,7 @@ static_assert(static_cast<int>(FST_ST_VCD_PROGRAM) == static_cast<int>(VLT_TRACE
 //=============================================================================
 // VerilatedFst
 
-VerilatedFst::VerilatedFst(void* fst)
-    : m_fst{fst} {}
+VerilatedFst::VerilatedFst(void* /*fst*/) {}
 
 VerilatedFst::~VerilatedFst() {
     if (m_fst) fstWriterClose(m_fst);
diff --git a/include/verilated_fst_c.h b/include/verilated_fst_c.h
index 1d9b07db7..b41b5a92c 100644
--- a/include/verilated_fst_c.h
+++ b/include/verilated_fst_c.h
@@ -48,7 +48,7 @@ private:
     //=========================================================================
     // FST specific internals
 
-    void* m_fst;
+    void* m_fst = nullptr;
     std::map<uint32_t, fstHandle> m_code2symbol;
     std::map<int, fstEnumHandle> m_local2fstdtype;
     std::list<std::string> m_curScope;
diff --git a/include/verilated_fst_sc.h b/include/verilated_fst_sc.h
index 878d0b867..872fe2e0b 100644
--- a/include/verilated_fst_sc.h
+++ b/include/verilated_fst_sc.h
@@ -51,7 +51,7 @@ public:
         }
         spTrace()->set_time_resolution(sc_get_time_resolution().to_string());
     }
-    virtual ~VerilatedFstSc() { close(); }
+    ~VerilatedFstSc() override { close(); }
 
     // METHODS
     /// Called by SystemC simulate()
diff --git a/include/verilated_imp.h b/include/verilated_imp.h
index 48bd6c42c..d55c7b228 100644
--- a/include/verilated_imp.h
+++ b/include/verilated_imp.h
@@ -143,11 +143,10 @@ class VerilatedThreadMsgQueue final {
 
 public:
     // CONSTRUCTORS
-    VerilatedThreadMsgQueue() {}
-    ~VerilatedThreadMsgQueue() {
-        // The only call of this with a non-empty queue is a fatal error.
-        // So this does not flush the queue, as the destination queue is not known to this class.
-    }
+    VerilatedThreadMsgQueue() = default;
+    ~VerilatedThreadMsgQueue() = default;
+    // The only call of destructor with a non-empty queue is a fatal error.
+    // So this does not flush the queue, as the destination queue is not known to this class.
 
 private:
     VL_UNCOPYABLE(VerilatedThreadMsgQueue);
@@ -188,11 +187,11 @@ class VerilatedFpList final {
 
 public:
     using const_iterator = FILE* const*;
-    explicit VerilatedFpList() {}
+    explicit VerilatedFpList() = default;
     const_iterator begin() const { return m_fp; }
     const_iterator end() const { return m_fp + m_sz; }
     std::size_t size() const { return m_sz; }
-    std::size_t capacity() const { return 31; }
+    static std::size_t capacity() { return 31; }
     void push_back(FILE* fd) {
         if (VL_LIKELY(size() < capacity())) m_fp[m_sz++] = fd;
     }
@@ -236,12 +235,11 @@ class VerilatedContextImp final : VerilatedContext {
         return s_s;
     }
 
-private:
+public:  // But only for verilated*.cpp
     // CONSTRUCTORS - no data can live here, use only VerilatedContext
     VerilatedContextImp() = delete;
     ~VerilatedContextImp() = delete;
 
-public:  // But only for verilated*.cpp
     // METHODS - extending into VerilatedContext, call via impp()->
 
     // Random seed handling
@@ -272,13 +270,12 @@ public:  // But only for verilated*.cpp
     std::string argPlusMatch(const char* prefixp) VL_MT_SAFE_EXCLUDES(m_argMutex);
     std::pair<int, char**> argc_argv() VL_MT_SAFE_EXCLUDES(m_argMutex);
 
-public:  // But only for verilated*.cpp
-    // METHODS - scope name
+    // METHODS - scope name - INTERNAL only for verilated*.cpp
     void scopeInsert(const VerilatedScope* scopep) VL_MT_SAFE;
     void scopeErase(const VerilatedScope* scopep) VL_MT_SAFE;
 
-public:  // But only for verilated*.cpp
-    // METHODS - file IO
+    // METHODS - file IO - INTERNAL only for verilated*.cpp
+
     IData fdNewMcd(const char* filenamep) VL_MT_SAFE_EXCLUDES(m_fdMutex) {
         const VerilatedLockGuard lock{m_fdMutex};
         if (m_fdFreeMct.empty()) return 0;
@@ -298,7 +295,7 @@ public:  // But only for verilated*.cpp
             const std::size_t start = std::max<std::size_t>(31UL + 1UL + 3UL, m_fdps.size());
             const std::size_t excess = 10;
             m_fdps.resize(start + excess);
-            std::fill(m_fdps.begin() + start, m_fdps.end(), (FILE*)0);
+            std::fill(m_fdps.begin() + start, m_fdps.end(), static_cast<FILE*>(nullptr));
             m_fdFree.resize(excess);
             for (std::size_t i = 0, id = start; i < m_fdFree.size(); ++i, ++id) {
                 m_fdFree[i] = id;
@@ -344,7 +341,7 @@ public:  // But only for verilated*.cpp
             if (VL_UNLIKELY(idx <= 2)) return;  // stdout/stdin/stderr
             if (VL_UNLIKELY(!m_fdps[idx])) return;  // Already free
             std::fclose(m_fdps[idx]);
-            m_fdps[idx] = (FILE*)0;
+            m_fdps[idx] = nullptr;
             m_fdFree.push_back(idx);
         } else {
             // MCD case
@@ -464,7 +461,6 @@ public:
     // METHODS - debug
     static void versionDump() VL_MT_SAFE;
 
-public:
     // METHODS - user scope tracking
     // We implement this as a single large map instead of one map per scope.
     // There's often many more scopes than userdata's and thus having a ~48byte
@@ -486,7 +482,8 @@ public:
         return it->second;
     }
 
-public:  // But only for verilated.cpp
+    // METHODS - But only for verilated.cpp
+
     // Symbol table destruction cleans up the entries for each scope.
     static void userEraseScope(const VerilatedScope* scopep) VL_MT_SAFE {
         // Slow ok - called once/scope on destruction, so we only iterate.
@@ -512,8 +509,7 @@ public:  // But only for verilated.cpp
         }
     }
 
-public:  // But only for verilated*.cpp
-    // METHODS - hierarchy
+    // METHODS - hierarchy - only for verilated*.cpp
     static void hierarchyAdd(const VerilatedScope* fromp, const VerilatedScope* top) VL_MT_SAFE {
         // Slow ok - called at construction for VPI accessible elements
         const VerilatedLockGuard lock{s().m_hierMapMutex};
@@ -534,8 +530,7 @@ public:  // But only for verilated*.cpp
         return &s().m_hierMap;
     }
 
-public:  // But only for verilated*.cpp
-    // METHODS - export names
+    // METHODS - export names - only for verilated*.cpp
 
     // Each function prototype is converted to a function number which we
     // then use to index a 2D table also indexed by scope number, because we
diff --git a/include/verilated_profiler.h b/include/verilated_profiler.h
index 61f2813d3..dcb906b45 100644
--- a/include/verilated_profiler.h
+++ b/include/verilated_profiler.h
@@ -165,14 +165,14 @@ class VlExecutionProfiler final : public VerilatedVirtualBase {
 public:
     // CONSTRUCTOR
     explicit VlExecutionProfiler(VerilatedContext& context);
-    virtual ~VlExecutionProfiler() = default;
+    ~VlExecutionProfiler() override = default;
 
     // METHODS
 
     // Is profiling enabled
     inline bool enabled() const { return m_enabled; }
     // Append a trace record to the trace buffer of the current thread
-    inline VlExecutionRecord& addRecord() {
+    static inline VlExecutionRecord& addRecord() {
         t_trace.emplace_back();
         return t_trace.back();
     }
diff --git a/include/verilated_save.h b/include/verilated_save.h
index 292bf39dd..728c2aead 100644
--- a/include/verilated_save.h
+++ b/include/verilated_save.h
@@ -77,7 +77,7 @@ public:
     virtual void flush() VL_MT_UNSAFE_ONE {}
     /// Write data to stream
     VerilatedSerialize& write(const void* __restrict datap, size_t size) VL_MT_UNSAFE_ONE {
-        const uint8_t* __restrict dp = (const uint8_t* __restrict)datap;
+        const uint8_t* __restrict dp = static_cast<const uint8_t* __restrict>(datap);
         while (size) {
             bufferCheck();
             size_t blk = size;
@@ -287,7 +287,8 @@ inline VerilatedDeserialize& operator>>(VerilatedDeserialize& os, std::string& r
     uint32_t len = 0;
     os >> len;
     rhs.resize(len);
-    return os.read((void*)rhs.data(), len);
+    // C cast is required below
+    return os.read((void*)(rhs.data()), len);
 }
 VerilatedSerialize& operator<<(VerilatedSerialize& os, VerilatedContext* rhsp);
 VerilatedDeserialize& operator>>(VerilatedDeserialize& os, VerilatedContext* rhsp);
diff --git a/include/verilated_sym_props.h b/include/verilated_sym_props.h
index 0f3fb4eeb..c62d59faa 100644
--- a/include/verilated_sym_props.h
+++ b/include/verilated_sym_props.h
@@ -134,7 +134,6 @@ public:
         initUnpacked(ulims);
     }
 
-public:
     ~VerilatedVarProps() = default;
     // METHODS
     bool magicOk() const { return m_magic == MAGIC; }
diff --git a/include/verilated_threads.h b/include/verilated_threads.h
index fdb45580e..5a0e35b9d 100644
--- a/include/verilated_threads.h
+++ b/include/verilated_threads.h
@@ -136,13 +136,10 @@ class VlWorkerThread final {
 private:
     // TYPES
     struct ExecRec {
-        VlExecFnp m_fnp;  // Function to execute
-        VlSelfP m_selfp;  // Symbol table to execute
-        bool m_evenCycle;  // Even/odd for flag alternation
-        ExecRec()
-            : m_fnp{nullptr}
-            , m_selfp{nullptr}
-            , m_evenCycle{false} {}
+        VlExecFnp m_fnp = nullptr;  // Function to execute
+        VlSelfP m_selfp = nullptr;  // Symbol table to execute
+        bool m_evenCycle = false;  // Even/odd for flag alternation
+        ExecRec() = default;
         ExecRec(VlExecFnp fnp, VlSelfP selfp, bool evenCycle)
             : m_fnp{fnp}
             , m_selfp{selfp}
@@ -222,7 +219,7 @@ public:
     // pool will create these threads and make them available to execute tasks
     // via this->workerp(index)->addTask(...)
     VlThreadPool(VerilatedContext* contextp, unsigned nThreads);
-    virtual ~VlThreadPool();
+    ~VlThreadPool() override;
 
     // METHODS
     inline int numThreads() const { return m_workers.size(); }
diff --git a/include/verilated_trace.h b/include/verilated_trace.h
index 66481602f..a66166363 100644
--- a/include/verilated_trace.h
+++ b/include/verilated_trace.h
@@ -401,7 +401,7 @@ protected:
     EData* const m_sigs_enabledp;  // Bit vector of enabled codes (nullptr = all on)
 
     explicit VerilatedTraceBuffer(Trace& owner);
-    virtual ~VerilatedTraceBuffer() = default;
+    ~VerilatedTraceBuffer() override = default;
 
 public:
     //=========================================================================
@@ -487,7 +487,7 @@ class VerilatedTraceOffloadBuffer final : public VerilatedTraceBuffer<T_Buffer>
     uint32_t* const m_offloadBufferEndp;  // End of offload buffer
 
     explicit VerilatedTraceOffloadBuffer(Trace& owner);
-    virtual ~VerilatedTraceOffloadBuffer() = default;
+    ~VerilatedTraceOffloadBuffer() override = default;
 
 public:
     //=========================================================================
diff --git a/include/verilated_vcd_c.h b/include/verilated_vcd_c.h
index 99b8ad48b..0d2003eba 100644
--- a/include/verilated_vcd_c.h
+++ b/include/verilated_vcd_c.h
@@ -113,7 +113,7 @@ protected:
     void commitTraceBuffer(Buffer*) override;
 
     // Configure sub-class
-    void configure(const VerilatedTraceConfig&) override { return; };
+    void configure(const VerilatedTraceConfig&) override{};
 
 public:
     //=========================================================================
@@ -253,7 +253,6 @@ public:
     /// Destruct, flush, and close the dump
     virtual ~VerilatedVcdC() { close(); }
 
-public:
     // METHODS - User called
 
     /// Return if file is open
diff --git a/include/verilated_vcd_sc.h b/include/verilated_vcd_sc.h
index 60504cf1e..5610fcd9a 100644
--- a/include/verilated_vcd_sc.h
+++ b/include/verilated_vcd_sc.h
@@ -54,7 +54,7 @@ public:
         spTrace()->set_time_resolution(sc_get_time_resolution().to_string());
     }
     /// Destruct, flush, and close the dump
-    virtual ~VerilatedVcdSc() { close(); }
+    ~VerilatedVcdSc() override { close(); }
 
     // METHODS - for SC kernel
     // Called by SystemC simulate()
diff --git a/include/verilated_vpi.h b/include/verilated_vpi.h
index 93555cf6d..9097b0c35 100644
--- a/include/verilated_vpi.h
+++ b/include/verilated_vpi.h
@@ -47,7 +47,7 @@ public:
     static bool callValueCbs() VL_MT_UNSAFE_ONE;
     /// Call callbacks of arbitrary types.
     /// User wrapper code should call this from their main loops.
-    static bool callCbs(const uint32_t reason) VL_MT_UNSAFE_ONE;
+    static bool callCbs(uint32_t reason) VL_MT_UNSAFE_ONE;
     /// Returns time of the next registered VPI callback, or
     /// ~(0ULL) if none are registered
     static QData cbNextDeadline() VL_MT_UNSAFE_ONE;
diff --git a/include/verilatedos.h b/include/verilatedos.h
index b01eac65c..5c74bc065 100644
--- a/include/verilatedos.h
+++ b/include/verilatedos.h
@@ -255,14 +255,11 @@
 // Internal coverage
 
 #ifdef VL_GCOV
-extern "C" {
-void __gcov_flush();  // gcc sources gcc/gcov-io.h has the prototype
-}
-// Flush internal code coverage data before e.g. std::abort()
-# define VL_GCOV_FLUSH() \
-    __gcov_flush()
+extern "C" void __gcov_dump();
+// Dump internal code coverage data before e.g. std::abort()
+# define VL_GCOV_DUMP() __gcov_dump()
 #else
-# define VL_GCOV_FLUSH()
+# define VL_GCOV_DUMP()
 #endif
 
 //=========================================================================
diff --git a/src/V3Ast.h b/src/V3Ast.h
index a1964880a..f482e009b 100644
--- a/src/V3Ast.h
+++ b/src/V3Ast.h
@@ -95,7 +95,7 @@ public:
     //   const char* ascii() const {...};
     enum en m_e;
     // cppcheck-suppress uninitVar  // responsibility of each subclass
-    inline VNType() {}
+    inline VNType() = default;
     // cppcheck-suppress noExplicitConstructor
     inline VNType(en _e)
         : m_e{_e} {}
@@ -1008,7 +1008,7 @@ public:
         return false;
     }
     //
-    VNumRange() {}
+    VNumRange() = default;
     VNumRange(int hi, int lo, bool littleEndian) { init(hi, lo, littleEndian); }
     VNumRange(int left, int right)
         : m_left{left}
@@ -1134,7 +1134,7 @@ class VNUser final {
     } m_u;
 
 public:
-    VNUser() {}
+    VNUser() = default;
     // non-explicit:
     // cppcheck-suppress noExplicitConstructor
     VNUser(int i) {
@@ -2464,7 +2464,7 @@ public:
     void fromp(AstNode* nodep) { return setOp1p(nodep); }
     void rhsp(AstNode* nodep) { return setOp2p(nodep); }
     void thsp(AstNode* nodep) { return setOp3p(nodep); }
-    void attrp(AstAttrOf* nodep) { return setOp4p((AstNode*)nodep); }
+    void attrp(AstAttrOf* nodep) { return setOp4p(reinterpret_cast<AstNode*>(nodep)); }
     // METHODS
     virtual bool same(const AstNode*) const override { return true; }
 };
@@ -2556,7 +2556,7 @@ public:
     AstNode* bodysp() const { return op4p(); }  // op4 = body of loop
     virtual bool isGateOptimizable() const override { return false; }
     virtual int instrCount() const override { return INSTR_COUNT_BRANCH; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 class AstNodeIf VL_NOT_FINAL : public AstNodeStmt {
@@ -2583,7 +2583,7 @@ public:
     virtual bool isGateOptimizable() const override { return false; }
     virtual bool isGateDedupable() const override { return true; }
     virtual int instrCount() const override { return INSTR_COUNT_BRANCH; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     void branchPred(VBranchPred flag) { m_branchPred = flag; }
     VBranchPred branchPred() const { return m_branchPred; }
     void isBoundsCheck(bool flag) { m_isBoundsCheck = flag; }
diff --git a/src/V3AstNodes.h b/src/V3AstNodes.h
index 5028e6894..af560f87d 100644
--- a/src/V3AstNodes.h
+++ b/src/V3AstNodes.h
@@ -189,7 +189,7 @@ public:
     explicit AstEmpty(FileLine* fl)
         : ASTGEN_SUPER_Empty(fl) {}
     ASTNODE_NODE_FUNCS(Empty)
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 class AstEmptyQueue final : public AstNodeMath {
@@ -199,7 +199,7 @@ public:
     ASTNODE_NODE_FUNCS(EmptyQueue)
     virtual string emitC() override { V3ERROR_NA_RETURN(""); }
     virtual string emitVerilog() override { return "{}"; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     virtual bool cleanOut() const override { return true; }
 };
 
@@ -246,7 +246,7 @@ public:
     bool littleEndian() const { return leftConst() < rightConst(); }
     virtual void dump(std::ostream& str) const override;
     virtual string emitC() { V3ERROR_NA_RETURN(""); }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 class AstBracketRange final : public AstNodeRange {
@@ -260,7 +260,7 @@ public:
     ASTNODE_NODE_FUNCS(BracketRange)
     virtual string emitC() { V3ERROR_NA_RETURN(""); }
     virtual string emitVerilog() { V3ERROR_NA_RETURN(""); }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     // Will be removed in V3Width, which relies on this
     // being a child not a dtype pointed node
     virtual bool maybePointedTo() const override { return false; }
@@ -275,7 +275,7 @@ public:
     ASTNODE_NODE_FUNCS(UnsizedRange)
     virtual string emitC() { V3ERROR_NA_RETURN(""); }
     virtual string emitVerilog() { return "[]"; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 class AstWildcardRange final : public AstNodeRange {
@@ -286,7 +286,7 @@ public:
     ASTNODE_NODE_FUNCS(WildcardRange)
     virtual string emitC() { V3ERROR_NA_RETURN(""); }
     virtual string emitVerilog() { return "[*]"; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 class AstGatePin final : public AstNodeMath {
@@ -660,7 +660,7 @@ class AstDynArrayDType final : public AstNodeDType {
     // Dynamic array data type, ie "[]"
     // Children: DTYPE (moved to refDTypep() in V3Width)
 private:
-    AstNodeDType* m_refDTypep;  // Elements of this type (after widthing)
+    AstNodeDType* m_refDTypep = nullptr;  // Elements of this type (after widthing)
 public:
     AstDynArrayDType(FileLine* fl, VFlagChildDType, AstNodeDType* dtp)
         : ASTGEN_SUPER_DynArrayDType(fl) {
@@ -1043,7 +1043,7 @@ class AstConstDType final : public AstNodeDType {
     // ConstDType are removed in V3LinkLValue and become AstVar::isConst.
     // When more generic types are supported AstConstDType will be propagated further.
 private:
-    AstNodeDType* m_refDTypep;  // Inherit from this base data type
+    AstNodeDType* m_refDTypep = nullptr;  // Inherit from this base data type
 public:
     AstConstDType(FileLine* fl, VFlagChildDType, AstNodeDType* dtp)
         : ASTGEN_SUPER_ConstDType(fl) {
@@ -1202,7 +1202,7 @@ class AstQueueDType final : public AstNodeDType {
     // Queue array data type, ie "[ $ ]"
     // Children: DTYPE (moved to refDTypep() in V3Width)
 private:
-    AstNodeDType* m_refDTypep;  // Elements of this type (after widthing)
+    AstNodeDType* m_refDTypep = nullptr;  // Elements of this type (after widthing)
 public:
     AstQueueDType(FileLine* fl, VFlagChildDType, AstNodeDType* dtp, AstNode* boundp)
         : ASTGEN_SUPER_QueueDType(fl) {
@@ -1396,7 +1396,7 @@ class AstMemberDType final : public AstNodeDType {
     // A member of a struct/union
     // PARENT: AstNodeUOrStructDType
 private:
-    AstNodeDType* m_refDTypep;  // Elements of this type (after widthing)
+    AstNodeDType* m_refDTypep = nullptr;  // Elements of this type (after widthing)
     string m_name;  // Name of variable
     string m_tag;  // Holds the string of the verilator tag -- used in XML output.
     int m_lsb = -1;  // Within this level's packed struct, the LSB of the first bit of the member
@@ -1585,8 +1585,8 @@ class AstEnumDType final : public AstNodeDType {
     // Children: ENUMVALUEs
 private:
     string m_name;  // Name from upper typedef, if any
-    AstNodeDType* m_refDTypep;  // Elements are of this type after V3Width
-    const int m_uniqueNum;
+    AstNodeDType* m_refDTypep = nullptr;  // Elements are of this type after V3Width
+    const int m_uniqueNum = 0;
 
 public:
     AstEnumDType(FileLine* fl, VFlagChildDType, AstNodeDType* dtp, AstNode* itemsp)
@@ -1709,7 +1709,7 @@ public:
         return true;
     }  // esp for V3Const::ifSameAssign
     virtual bool isPredictOptimizable() const override { return true; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     virtual int instrCount() const override { return widthInstrs(); }
     // Special operators
     // Return base var (or const) nodep dereferences
@@ -1750,7 +1750,7 @@ public:
         return true;
     }  // esp for V3Const::ifSameAssign
     virtual bool isPredictOptimizable() const override { return false; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     virtual int instrCount() const override { return widthInstrs(); }
 };
 
@@ -1788,7 +1788,7 @@ public:
         return true;
     }  // esp for V3Const::ifSameAssign
     virtual bool isPredictOptimizable() const override { return false; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     virtual int instrCount() const override { return widthInstrs(); }
 };
 
@@ -1815,7 +1815,7 @@ public:
     virtual bool cleanRhs() const override { return true; }
     virtual bool sizeMattersLhs() const override { return false; }
     virtual bool sizeMattersRhs() const override { return false; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 class AstSelLoopVars final : public AstNode {
@@ -1828,7 +1828,7 @@ public:
         addNOp2p(elementsp);
     }
     ASTNODE_NODE_FUNCS(SelLoopVars)
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     virtual bool maybePointedTo() const override { return false; }
     AstNode* fromp() const { return op1p(); }
     void fromp(AstNode* nodep) { setOp1p(nodep); }
@@ -3358,7 +3358,7 @@ public:
         addNOp2p(exprp);
     }
     ASTNODE_NODE_FUNCS(WithParse)
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     //
     AstNode* funcrefp() const { return op1p(); }
     AstNode* exprp() const { return op2p(); }
@@ -3378,7 +3378,7 @@ public:
         , m_name{name}
         , m_index(index) {}
     ASTNODE_NODE_FUNCS(LambdaArgRef)
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     virtual string emitVerilog() override { return name(); }
     virtual string emitC() override { V3ERROR_NA_RETURN(""); }
     virtual bool cleanOut() const override { return true; }
@@ -3405,7 +3405,7 @@ public:
         addNOp3p(exprp);
     }
     ASTNODE_NODE_FUNCS(With)
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     virtual bool hasDType() const override { return true; }
     virtual const char* broken() const override {
         BROKEN_RTN(!indexArgRefp());  // varp needed to know lambda's arg dtype
@@ -3585,7 +3585,7 @@ public:
         addNOp2p(bodysp);
     }
     ASTNODE_NODE_FUNCS(AlwaysPublic)
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     //
     AstSenTree* sensesp() const { return VN_AS(op1p(), SenTree); }  // op1 = Sensitivity list
     AstNode* bodysp() const { return op2p(); }  // op2 = Statements to evaluate
@@ -3919,7 +3919,7 @@ public:
     }
     ASTNODE_NODE_FUNCS(CoverToggle)
     virtual int instrCount() const override { return 3 + INSTR_COUNT_BRANCH + INSTR_COUNT_LD; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     virtual bool isGateOptimizable() const override { return false; }
     virtual bool isPredictOptimizable() const override { return true; }
     virtual bool isOutputter() const override {
@@ -3941,7 +3941,7 @@ public:
         setNOp2p(stmtsp);
     }
     ASTNODE_NODE_FUNCS(Delay)
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     //
     AstNode* lhsp() const { return op1p(); }  // op1 = delay value
     void lhsp(AstNode* nodep) { setOp1p(nodep); }
@@ -4147,7 +4147,7 @@ public:
     virtual bool isPredictOptimizable() const override { return false; }
     virtual bool isOutputter() const override { return true; }
     virtual bool cleanOut() const { return true; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     VDumpCtlType ctlType() const { return m_ctlType; }
     AstNode* exprp() const { return op1p(); }  // op2 = Expressions to output
     void exprp(AstNode* nodep) { setOp1p(nodep); }
@@ -4218,7 +4218,7 @@ public:
     virtual bool isOutputter() const override { return false; }
     virtual bool cleanOut() const { return false; }
     virtual int instrCount() const override { return INSTR_COUNT_PLI; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     void fmtp(AstSFormatF* nodep) { addOp1p(nodep); }  // op1 = To-String formatter
     AstSFormatF* fmtp() const { return VN_AS(op1p(), SFormatF); }
     AstNode* lhsp() const { return op3p(); }
@@ -4241,7 +4241,7 @@ public:
     virtual bool isPure() const override { return true; }
     virtual bool isOutputter() const override { return false; }
     virtual int instrCount() const override { return 0; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     AstNode* lhsp() const { return op1p(); }  // op1 = Expressions to eval
     void lhsp(AstNode* nodep) { addOp1p(nodep); }  // op1 = Expressions to eval
 };
@@ -4282,7 +4282,7 @@ public:
     virtual bool isPure() const override { return false; }
     virtual bool isOutputter() const override { return true; }
     virtual bool isUnlikely() const override { return true; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     AstNode* filep() const { return op2p(); }
     void filep(AstNodeVarRef* nodep) { setNOp2p(nodep); }
 };
@@ -4303,7 +4303,7 @@ public:
     virtual bool isPure() const override { return false; }
     virtual bool isOutputter() const override { return true; }
     virtual bool isUnlikely() const override { return true; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     AstNode* filep() const { return op1p(); }
     AstNode* filenamep() const { return op2p(); }
     AstNode* modep() const { return op3p(); }
@@ -4324,7 +4324,7 @@ public:
     virtual bool isPure() const override { return false; }
     virtual bool isOutputter() const override { return true; }
     virtual bool isUnlikely() const override { return true; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     AstNode* filep() const { return op1p(); }
     AstNode* filenamep() const { return op2p(); }
 };
@@ -4344,7 +4344,7 @@ public:
     virtual bool isPure() const override { return false; }
     virtual bool isOutputter() const override { return true; }
     virtual bool isUnlikely() const override { return true; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     AstNode* filep() const { return op2p(); }
     void filep(AstNodeVarRef* nodep) { setNOp2p(nodep); }
 };
@@ -4372,7 +4372,7 @@ public:
     virtual bool isPure() const override { return false; }  // SPECIAL: has 'visual' ordering
     virtual bool isOutputter() const override { return true; }  // SPECIAL: makes output
     virtual bool cleanOut() const override { return false; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     AstNode* memp() const { return op1p(); }
     void memp(AstNode* nodep) { setOp1p(nodep); }
     AstNode* filep() const { return op2p(); }
@@ -4401,7 +4401,7 @@ public:
     virtual bool isOutputter() const override { return true; }
     virtual bool isUnlikely() const override { return true; }
     virtual bool cleanOut() const override { return false; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     AstNode* filep() const { return op2p(); }
     void filep(AstNodeVarRef* nodep) { setNOp2p(nodep); }
 };
@@ -4424,7 +4424,7 @@ public:
     virtual bool isOutputter() const override { return true; }
     virtual bool isUnlikely() const override { return true; }
     virtual bool cleanOut() const override { return false; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     AstNode* filep() const { return op2p(); }
     void filep(AstNodeVarRef* nodep) { setNOp2p(nodep); }
 };
@@ -4450,7 +4450,7 @@ public:
     virtual bool isPure() const override { return false; }  // SPECIAL: has 'visual' ordering
     virtual bool isOutputter() const override { return true; }  // SPECIAL: makes output
     virtual bool cleanOut() const override { return false; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     AstNode* filep() const { return op2p(); }
     void filep(AstNode* nodep) { setOp2p(nodep); }
     AstNode* offset() const { return op3p(); }
@@ -4614,7 +4614,7 @@ public:
     virtual bool isPure() const override { return false; }
     virtual bool isOutputter() const override { return true; }
     virtual bool isUnlikely() const override { return true; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     AstNode* lhsp() const { return op1p(); }
 };
 
@@ -4635,7 +4635,7 @@ public:
     virtual bool isOutputter() const override { return true; }
     virtual bool isUnlikely() const override { return true; }
     virtual bool cleanOut() const override { return true; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     AstNode* lhsp() const { return op1p(); }
 };
 
@@ -4656,7 +4656,7 @@ public:
     virtual bool isPredictOptimizable() const override { return false; }
     virtual bool isPure() const override { return !outp(); }
     virtual bool cleanOut() const override { return true; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     AstNode* searchp() const { return op1p(); }  // op1 = Search expression
     void searchp(AstNode* nodep) { setOp1p(nodep); }
     AstNode* outp() const { return op2p(); }  // op2 = Expressions to output
@@ -4678,7 +4678,7 @@ public:
     virtual bool isGateOptimizable() const override { return false; }
     virtual bool isPredictOptimizable() const override { return false; }
     virtual bool cleanOut() const override { return true; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     AstNode* searchp() const { return op1p(); }  // op1 = Search expression
     void searchp(AstNode* nodep) { setOp1p(nodep); }
 };
@@ -4702,7 +4702,7 @@ public:
     AstNode* bodysp() const { return op4p(); }  // op4 = body of loop
     virtual bool isGateOptimizable() const override { return false; }
     virtual int instrCount() const override { return INSTR_COUNT_BRANCH; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 class AstRepeat final : public AstNodeStmt {
@@ -4719,7 +4719,7 @@ public:
         return false;
     }  // Not relevant - converted to FOR
     virtual int instrCount() const override { return INSTR_COUNT_BRANCH; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 class AstWait final : public AstNodeStmt {
@@ -4752,7 +4752,7 @@ public:
     void addIncsp(AstNode* newp) { addOp4p(newp); }
     virtual bool isGateOptimizable() const override { return false; }
     virtual int instrCount() const override { return INSTR_COUNT_BRANCH; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     // Stop statement searchback here
     virtual void addBeforeStmt(AstNode* newp, AstNode* belowp) override;
     // Stop statement searchback here
@@ -4872,7 +4872,7 @@ public:
     ASTNODE_NODE_FUNCS(JumpBlock)
     virtual int instrCount() const override { return 0; }
     virtual bool maybePointedTo() const override { return true; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     // op1 = Statements
     AstNode* stmtsp() const { return op1p(); }  // op1 = List of statements
     void addStmtsp(AstNode* nodep) { addNOp1p(nodep); }
@@ -4959,7 +4959,7 @@ public:
     virtual bool cleanOut() const override { return true; }
     virtual int instrCount() const override { return widthInstrs(); }
     AstNode* defaultp() const { return op1p(); }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 class AstSetAssoc final : public AstNodeMath {
     // Set an assoc array element and return object, '{}
@@ -4981,7 +4981,7 @@ public:
     AstNode* lhsp() const { return op1p(); }
     AstNode* keyp() const { return op2p(); }
     AstNode* valuep() const { return op3p(); }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 class AstConsWildcard final : public AstNodeMath {
@@ -5000,7 +5000,7 @@ public:
     virtual bool cleanOut() const override { return true; }
     virtual int instrCount() const override { return widthInstrs(); }
     AstNode* defaultp() const { return op1p(); }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 class AstSetWildcard final : public AstNodeMath {
     // Set a wildcard assoc array element and return object, '{}
@@ -5022,7 +5022,7 @@ public:
     AstNode* lhsp() const { return op1p(); }
     AstNode* keyp() const { return op2p(); }
     AstNode* valuep() const { return op3p(); }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 class AstConsDynArray final : public AstNodeMath {
@@ -5043,7 +5043,7 @@ public:
     virtual int instrCount() const override { return widthInstrs(); }
     AstNode* lhsp() const { return op1p(); }  // op1 = expression
     AstNode* rhsp() const { return op2p(); }  // op2 = expression
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 class AstConsQueue final : public AstNodeMath {
@@ -5064,7 +5064,7 @@ public:
     virtual int instrCount() const override { return widthInstrs(); }
     AstNode* lhsp() const { return op1p(); }  // op1 = expression
     AstNode* rhsp() const { return op2p(); }  // op2 = expression
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 class AstBegin final : public AstNodeBlock {
@@ -5241,7 +5241,7 @@ public:
         : ASTGEN_SUPER_New(fl, false, "new", pinsp) {}
     ASTNODE_NODE_FUNCS(New)
     virtual bool cleanOut() const { return true; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     virtual bool hasDType() const override { return true; }
     virtual int instrCount() const override { return widthInstrs(); }
 };
@@ -5260,7 +5260,7 @@ public:
     virtual string emitVerilog() override { return "new"; }
     virtual string emitC() override { V3ERROR_NA_RETURN(""); }
     virtual bool cleanOut() const override { return true; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     virtual int instrCount() const override { return widthInstrs(); }
     AstNode* rhsp() const { return op1p(); }
 };
@@ -5280,7 +5280,7 @@ public:
     virtual string emitVerilog() override { return "new"; }
     virtual string emitC() override { V3ERROR_NA_RETURN(""); }
     virtual bool cleanOut() const override { return true; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     virtual int instrCount() const override { return widthInstrs(); }
     AstNode* sizep() const { return op1p(); }
     AstNode* rhsp() const { return op2p(); }
@@ -5709,7 +5709,7 @@ public:
     virtual bool isGateOptimizable() const override { return false; }
     virtual bool isPredictOptimizable() const override { return false; }
     virtual int instrCount() const override { return INSTR_COUNT_PLI; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     bool combinable(const AstRand* samep) const {
         return !seedp() && !samep->seedp() && reset() == samep->reset()
                && urandom() == samep->urandom();
@@ -5760,7 +5760,7 @@ public:
     virtual bool isGateOptimizable() const override { return false; }
     virtual bool isPredictOptimizable() const override { return false; }
     virtual int instrCount() const override { return INSTR_COUNT_TIME; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     virtual void dump(std::ostream& str = std::cout) const override;
     void timeunit(const VTimescale& flag) { m_timeunit = flag; }
     VTimescale timeunit() const { return m_timeunit; }
@@ -5781,7 +5781,7 @@ public:
     virtual bool isGateOptimizable() const override { return false; }
     virtual bool isPredictOptimizable() const override { return false; }
     virtual int instrCount() const override { return INSTR_COUNT_TIME; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     virtual void dump(std::ostream& str = std::cout) const override;
     void timeunit(const VTimescale& flag) { m_timeunit = flag; }
     VTimescale timeunit() const { return m_timeunit; }
@@ -5806,7 +5806,7 @@ public:
     virtual bool isSubstOptimizable() const override { return false; }
     virtual bool isPredictOptimizable() const override { return false; }
     virtual int instrCount() const override { return INSTR_COUNT_PLI; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 //======================================================================
@@ -6394,7 +6394,7 @@ public:
     virtual bool cleanOut() const override { return true; }
     virtual bool cleanLhs() const override { return true; }
     virtual bool sizeMattersLhs() const override { return false; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 class AstFEof final : public AstNodeUniop {
@@ -6436,7 +6436,7 @@ public:
     AstNode* filep() const { return op1p(); }
     void strp(AstNode* nodep) { setOp2p(nodep); }
     AstNode* strp() const { return op2p(); }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 class AstFGetC final : public AstNodeUniop {
@@ -8561,7 +8561,7 @@ public:
     AstNode* exprp() const { return op1p(); }  // op1 = expression
     AstSenTree* sentreep() const { return VN_AS(op2p(), SenTree); }  // op2 = clock domain
     void sentreep(AstSenTree* sentreep) { addOp2p(sentreep); }  // op2 = clock domain
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 class AstPast final : public AstNodeMath {
@@ -8584,7 +8584,7 @@ public:
     AstNode* ticksp() const { return op2p(); }  // op2 = ticks or nullptr means 1
     AstSenTree* sentreep() const { return VN_AS(op4p(), SenTree); }  // op4 = clock domain
     void sentreep(AstSenTree* sentreep) { addOp4p(sentreep); }  // op4 = clock domain
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 class AstRose final : public AstNodeMath {
@@ -8605,7 +8605,7 @@ public:
     AstNode* exprp() const { return op1p(); }  // op1 = expression
     AstSenTree* sentreep() const { return VN_AS(op2p(), SenTree); }  // op2 = clock domain
     void sentreep(AstSenTree* sentreep) { addOp2p(sentreep); }  // op2 = clock domain
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 class AstSampled final : public AstNodeMath {
@@ -8624,7 +8624,7 @@ public:
     virtual bool cleanOut() const override { V3ERROR_NA_RETURN(""); }
     virtual int instrCount() const override { return 0; }
     AstNode* exprp() const { return op1p(); }  // op1 = expression
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 class AstStable final : public AstNodeMath {
@@ -8645,7 +8645,7 @@ public:
     AstNode* exprp() const { return op1p(); }  // op1 = expression
     AstSenTree* sentreep() const { return VN_AS(op2p(), SenTree); }  // op2 = clock domain
     void sentreep(AstSenTree* sentreep) { addOp2p(sentreep); }  // op2 = clock domain
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 class AstPattern final : public AstNodeMath {
@@ -8720,7 +8720,7 @@ public:
     void rhsp(AstNode* nodep) { return setOp2p(nodep); }
     AstSenTree* sentreep() const { return VN_AS(op4p(), SenTree); }  // op4 = clock domain
     void sentreep(AstSenTree* sentreep) { addOp4p(sentreep); }  // op4 = clock domain
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 //======================================================================
@@ -8941,7 +8941,7 @@ public:
     virtual bool isPredictOptimizable() const override { return false; }
     virtual bool isPure() const override { return false; }
     virtual bool isOutputter() const override { return true; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
 };
 
 //======================================================================
@@ -8961,7 +8961,7 @@ public:
     ASTNODE_BASE_FUNCS(NodeFile)
     virtual void dump(std::ostream& str) const override;
     virtual string name() const override { return m_name; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     void tblockp(AstTextBlock* tblockp) { setOp1p(tblockp); }
     AstTextBlock* tblockp() { return VN_AS(op1p(), TextBlock); }
 };
@@ -9225,7 +9225,7 @@ public:
     }
     ASTNODE_NODE_FUNCS(CReturn)
     virtual int instrCount() const override { return widthInstrs(); }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     //
     AstNode* lhsp() const { return op1p(); }
 };
@@ -9256,7 +9256,7 @@ public:
     virtual bool cleanOut() const override { return m_cleanOut; }
     virtual string emitVerilog() override { V3ERROR_NA_RETURN(""); }
     virtual string emitC() override { V3ERROR_NA_RETURN(""); }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     void addBodysp(AstNode* nodep) { addNOp1p(nodep); }
     AstNode* bodysp() const { return op1p(); }  // op1 = expressions to print
     bool pure() const { return m_pure; }
@@ -9273,7 +9273,7 @@ public:
     ASTNODE_NODE_FUNCS(CReset)
     virtual bool isGateOptimizable() const override { return false; }
     virtual bool isPredictOptimizable() const override { return false; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     AstVarRef* varrefp() const { return VN_AS(op1p(), VarRef); }  // op1 = varref to reset
 };
 
@@ -9291,7 +9291,7 @@ public:
     ASTNODE_NODE_FUNCS(CStmt)
     virtual bool isGateOptimizable() const override { return false; }
     virtual bool isPredictOptimizable() const override { return false; }
-    virtual bool same(const AstNode* samep) const override { return true; }
+    virtual bool same(const AstNode* /*samep*/) const override { return true; }
     void addBodysp(AstNode* nodep) { addNOp1p(nodep); }
     AstNode* bodysp() const { return op1p(); }  // op1 = expressions to print
 };
@@ -9387,7 +9387,7 @@ class AstTypeTable final : public AstNode {
     AstEmptyQueueDType* m_emptyQueuep = nullptr;
     AstQueueDType* m_queueIndexp = nullptr;
     AstVoidDType* m_voidp = nullptr;
-    AstBasicDType* m_basicps[VBasicDTypeKwd::_ENUM_MAX];
+    AstBasicDType* m_basicps[VBasicDTypeKwd::_ENUM_MAX]{};
     //
     using DetailedMap = std::map<VBasicTypeKey, AstBasicDType*>;
     DetailedMap m_detailedMap;
diff --git a/src/V3Dead.cpp b/src/V3Dead.cpp
index 243c580bf..f64a24453 100644
--- a/src/V3Dead.cpp
+++ b/src/V3Dead.cpp
@@ -85,7 +85,7 @@ private:
         }
         if (AstNode* const subnodep = nodep->getChildDTypep()) subnodep->user1Inc();
     }
-    void checkVarRef(AstNodeVarRef* nodep) {
+    void checkVarRef(AstNodeVarRef* nodep) const {
         if (nodep->classOrPackagep() && m_elimCells) nodep->classOrPackagep(nullptr);
     }
     void checkDType(AstNodeDType* nodep) {
@@ -316,7 +316,7 @@ private:
             }
         }
     }
-    bool mightElimVar(AstVar* nodep) {
+    bool mightElimVar(AstVar* nodep) const {
         if (nodep->isSigPublic()) return false;  // Can't elim publics!
         if (nodep->isIO() || nodep->isClassMember()) return false;
         if (nodep->isTemp() && !nodep->isTrace()) return true;
diff --git a/src/V3DupFinder.h b/src/V3DupFinder.h
index ed8d13097..1ee51a992 100644
--- a/src/V3DupFinder.h
+++ b/src/V3DupFinder.h
@@ -44,7 +44,7 @@ class V3DupFinder final : private std::multimap<V3Hash, AstNode*> {
     using Super = std::multimap<V3Hash, AstNode*>;
 
     // MEMBERS
-    const V3Hasher* const m_hasherp;  // Pointer to owned hasher
+    const V3Hasher* const m_hasherp = nullptr;  // Pointer to owned hasher
     const V3Hasher& m_hasher;  // Reference to hasher
 
 public:
@@ -53,8 +53,7 @@ public:
         : m_hasherp{new V3Hasher}
         , m_hasher{*m_hasherp} {}
     explicit V3DupFinder(const V3Hasher& hasher)
-        : m_hasherp{nullptr}
-        , m_hasher{hasher} {}
+        : m_hasher{hasher} {}
     ~V3DupFinder() {
         if (m_hasherp) delete m_hasherp;
     }
diff --git a/src/V3Error.cpp b/src/V3Error.cpp
index 1f1f8d08f..f032e7c06 100644
--- a/src/V3Error.cpp
+++ b/src/V3Error.cpp
@@ -167,7 +167,7 @@ void V3Error::vlAbortOrExit() {
 }
 
 void V3Error::vlAbort() {
-    VL_GCOV_FLUSH();
+    VL_GCOV_DUMP();
     std::abort();
 }
 
diff --git a/src/V3FileLine.cpp b/src/V3FileLine.cpp
index 016329fc7..d82c8966e 100644
--- a/src/V3FileLine.cpp
+++ b/src/V3FileLine.cpp
@@ -126,7 +126,7 @@ string VFileContent::getLine(int lineno) const {
             return "";
         }
     }
-    const string text = m_lines[lineno];
+    string text = m_lines[lineno];
     UINFO(9, "Get Stream[ct" << m_id << "+" << lineno << "]: " << text);
     return text;
 }
diff --git a/src/V3FileLine.h b/src/V3FileLine.h
index 328b682cd..d49d5e44a 100644
--- a/src/V3FileLine.h
+++ b/src/V3FileLine.h
@@ -162,7 +162,7 @@ public:
         m_firstColumn = firstColumn;
         m_lastColumn = lastColumn;
     }
-    void language(V3LangCode lang) { singleton().numberToLang(filenameno(), lang); }
+    void language(V3LangCode lang) const { singleton().numberToLang(filenameno(), lang); }
     void filename(const string& name) { m_filenameno = singleton().nameToNumber(name); }
     void parent(FileLine* fileline) { m_parent = fileline; }
     void lineDirective(const char* textp, int& enterExitRef);
@@ -213,7 +213,7 @@ public:
     void warnStyleOff(bool flag);
     void warnStateFrom(const FileLine& from) { m_warnOn = from.m_warnOn; }
     void warnResetDefault() { warnStateFrom(defaultFileLine()); }
-    bool lastWarnWaived() { return m_waive; }
+    bool lastWarnWaived() const { return m_waive; }
 
     // Specific flag ACCESSORS/METHODS
     bool celldefineOn() const { return m_warnOn.test(V3ErrorCode::I_CELLDEFINE); }
diff --git a/src/V3HierBlock.cpp b/src/V3HierBlock.cpp
index 22006fa23..2430e19db 100644
--- a/src/V3HierBlock.cpp
+++ b/src/V3HierBlock.cpp
@@ -201,7 +201,7 @@ string V3HierBlock::hierGenerated(bool withDir) const {
 }
 
 string V3HierBlock::vFileIfNecessary() const {
-    const string filename = V3Os::filenameRealPath(m_modp->fileline()->filename());
+    string filename = V3Os::filenameRealPath(m_modp->fileline()->filename());
     for (const string& v : v3Global.opt.vFiles()) {
         // Already listed in vFiles, so no need to add the file.
         if (filename == V3Os::filenameRealPath(v)) return "";
diff --git a/src/V3Options.cpp b/src/V3Options.cpp
index de4428b02..cb9720fbd 100644
--- a/src/V3Options.cpp
+++ b/src/V3Options.cpp
@@ -339,7 +339,7 @@ bool V3Options::hasParameter(const string& name) {
 }
 
 string V3Options::parameter(const string& name) {
-    const string value = m_parameters.find(name)->second;
+    string value = m_parameters.find(name)->second;
     m_parameters.erase(m_parameters.find(name));
     return value;
 }
@@ -477,7 +477,7 @@ string V3Options::fileExists(const string& filename) {
         return "";  // Not found
     }
     // Check if it is a directory, ignore if so
-    const string filenameOut = V3Os::filenameFromDirBase(dir, basename);
+    string filenameOut = V3Os::filenameFromDirBase(dir, basename);
     if (!fileStatNormal(filenameOut)) return "";  // Directory
     return filenameOut;
 }
@@ -518,11 +518,11 @@ string V3Options::filePath(FileLine* fl, const string& modname, const string& la
     // using the incdir and libext's.
     // Return "" if not found.
     for (const string& dir : m_impp->m_incDirUsers) {
-        const string exists = filePathCheckOneDir(modname, dir);
+        string exists = filePathCheckOneDir(modname, dir);
         if (exists != "") return exists;
     }
     for (const string& dir : m_impp->m_incDirFallbacks) {
-        const string exists = filePathCheckOneDir(modname, dir);
+        string exists = filePathCheckOneDir(modname, dir);
         if (exists != "") return exists;
     }
 
diff --git a/src/V3ParseGrammar.cpp b/src/V3ParseGrammar.cpp
index f2d57f289..38bae0374 100644
--- a/src/V3ParseGrammar.cpp
+++ b/src/V3ParseGrammar.cpp
@@ -270,7 +270,8 @@ string V3ParseGrammar::deQuote(FileLine* fileline, string text) {
                 } else if (*cp == 'x' && isxdigit(cp[1])
                            && isxdigit(cp[2])) {  // SystemVerilog 3.1
 #define vl_decodexdigit(c) ((isdigit(c) ? ((c) - '0') : (tolower((c)) - 'a' + 10)))
-                    newtext += (char)(16 * vl_decodexdigit(cp[1]) + vl_decodexdigit(cp[2]));
+                    newtext
+                        += static_cast<char>(16 * vl_decodexdigit(cp[1]) + vl_decodexdigit(cp[2]));
                     cp += 2;
                 } else if (isalnum(*cp)) {
                     fileline->v3error("Unknown escape sequence: \\" << *cp);
diff --git a/src/V3ParseImp.h b/src/V3ParseImp.h
index 777e205cc..cc1918865 100644
--- a/src/V3ParseImp.h
+++ b/src/V3ParseImp.h
@@ -173,9 +173,10 @@ public:
     }
     static int debug() {
         static int level = -1;
-        if (VL_UNLIKELY(level < 0))
+        if (VL_UNLIKELY(level < 0)) {
             level = std::max(std::max(debugBison(), debugFlex()),
                              v3Global.opt.debugSrcLevel("V3ParseImp"));
+        }
         return level;
     }
 
@@ -273,7 +274,7 @@ public:
 
     //==== Symbol tables
     V3ParseSym* symp() { return m_symp; }
-    AstPackage* unitPackage(FileLine* fl) {
+    AstPackage* unitPackage(FileLine* /*fl*/) {
         // Find one made earlier?
         const VSymEnt* const rootSymp
             = symp()->symRootp()->findIdFlat(AstPackage::dollarUnitName());
diff --git a/src/V3PartitionGraph.h b/src/V3PartitionGraph.h
index 2fba23172..262a2b286 100644
--- a/src/V3PartitionGraph.h
+++ b/src/V3PartitionGraph.h
@@ -30,7 +30,7 @@
 
 class AbstractMTask VL_NOT_FINAL : public V3GraphVertex {
 public:
-    AbstractMTask(V3Graph* graphp)
+    explicit AbstractMTask(V3Graph* graphp)
         : V3GraphVertex{graphp} {}
     virtual ~AbstractMTask() override = default;
     virtual uint32_t id() const = 0;
@@ -42,7 +42,7 @@ public:
     // TYPES
     using VxList = std::list<MTaskMoveVertex*>;
     // CONSTRUCTORS
-    AbstractLogicMTask(V3Graph* graphp)
+    explicit AbstractLogicMTask(V3Graph* graphp)
         : AbstractMTask{graphp} {}
     virtual ~AbstractLogicMTask() override = default;
     // METHODS
diff --git a/src/V3PreProc.cpp b/src/V3PreProc.cpp
index 7301d6b1e..7dfeb9c12 100644
--- a/src/V3PreProc.cpp
+++ b/src/V3PreProc.cpp
@@ -1612,7 +1612,7 @@ string V3PreProcImp::getline() {
 
     // Make new string with data up to the newline.
     const int len = rtnp - m_lineChars.c_str() + 1;
-    const string theLine(m_lineChars, 0, len);
+    string theLine(m_lineChars, 0, len);
     m_lineChars = m_lineChars.erase(0, len);  // Remove returned characters
     if (debug() >= 4) {
         const string lncln = V3PreLex::cleanDbgStrg(theLine);
diff --git a/src/V3Simulate.h b/src/V3Simulate.h
index 195139cd2..378cdd0e4 100644
--- a/src/V3Simulate.h
+++ b/src/V3Simulate.h
@@ -183,7 +183,7 @@ public:
             }
             m_whyNotOptimizable = why;
             std::ostringstream stack;
-            for (auto& callstack : vlstd::reverse_view(m_callStack)) {
+            for (const auto& callstack : vlstd::reverse_view(m_callStack)) {
                 AstFuncRef* const funcp = callstack->m_funcp;
                 stack << "\n        " << funcp->fileline() << "... Called from "
                       << funcp->prettyName() << "() with parameters:";
@@ -193,9 +193,10 @@ public:
                     AstVar* const portp = conIt->first;
                     AstNode* const pinp = conIt->second->exprp();
                     AstNodeDType* const dtypep = pinp->dtypep();
-                    if (AstConst* const valp = fetchConstNull(pinp))
+                    if (AstConst* const valp = fetchConstNull(pinp)) {
                         stack << "\n           " << portp->prettyName() << " = "
                               << prettyNumber(&valp->num(), dtypep);
+                    }
                 }
             }
             m_whyNotOptimizable += stack.str();
@@ -380,7 +381,7 @@ private:
         UASSERT_OBJ(vscp, nodep, "Not linked");
         return vscp;
     }
-    int unrollCount() {
+    int unrollCount() const {
         return m_params ? v3Global.opt.unrollCount() * 16 : v3Global.opt.unrollCount();
     }
     bool jumpingOver(AstNode* nodep) {
diff --git a/src/V3TraceDecl.cpp b/src/V3TraceDecl.cpp
index 791034307..09c2ac8f5 100644
--- a/src/V3TraceDecl.cpp
+++ b/src/V3TraceDecl.cpp
@@ -192,7 +192,9 @@ private:
         m_subFuncSize += stmtp->nodeCount();
     }
 
-    std::string getScopeChar(VltTraceScope sct) { return std::string(1, (char)(0x80 + sct)); }
+    std::string getScopeChar(VltTraceScope sct) {
+        return std::string(1, static_cast<char>(0x80 + sct));
+    }
 
     std::string addAboveInterface(const std::string& scopeName) {
         std::string out;
diff --git a/src/V3Tristate.cpp b/src/V3Tristate.cpp
index 6a9d7f4a8..da76ddb17 100644
--- a/src/V3Tristate.cpp
+++ b/src/V3Tristate.cpp
@@ -360,7 +360,7 @@ class TristateVisitor final : public TristateBaseVisitor {
     VDouble0 m_statTriSigs;  // stat tracking
 
     // METHODS
-    string dbgState() {
+    string dbgState() const {
         string o = (m_graphing ? " gr " : " ng ");
         if (m_alhs) o += "alhs ";
         return o;
diff --git a/src/V3Unroll.cpp b/src/V3Unroll.cpp
index 429708301..769faf369 100644
--- a/src/V3Unroll.cpp
+++ b/src/V3Unroll.cpp
@@ -58,7 +58,7 @@ private:
     VL_DEBUG_FUNC;  // Declare debug()
 
     // VISITORS
-    bool cantUnroll(AstNode* nodep, const char* reason) {
+    bool cantUnroll(AstNode* nodep, const char* reason) const {
         if (m_generate)
             nodep->v3warn(E_UNSUPPORTED, "Unsupported: Can't unroll generate for; " << reason);
         UINFO(3, "   Can't Unroll: " << reason << " :" << nodep << endl);
diff --git a/src/VlcBucket.h b/src/VlcBucket.h
index ef5fdcdc7..0160ae1b2 100644
--- a/src/VlcBucket.h
+++ b/src/VlcBucket.h
@@ -96,20 +96,20 @@ public:
     }
     uint64_t popCount() const {
         uint64_t pop = 0;
-        for (uint64_t i = 0; i < m_dataSize; i++) {
-            if (hits(i)) pop++;
+        for (uint64_t i = 0; i < m_dataSize; ++i) {
+            if (hits(i)) ++pop;
         }
         return pop;
     }
     uint64_t dataPopCount(const VlcBuckets& remaining) {
         uint64_t pop = 0;
-        for (uint64_t i = 0; i < m_dataSize; i++) {
-            if (hits(i) && remaining.hits(i)) pop++;
+        for (uint64_t i = 0; i < m_dataSize; ++i) {
+            if (hits(i) && remaining.hits(i)) ++pop;
         }
         return pop;
     }
     void orData(const VlcBuckets& ordata) {
-        for (uint64_t i = 0; i < m_dataSize; i++) {
+        for (uint64_t i = 0; i < m_dataSize; ++i) {
             if (hits(i) && ordata.hits(i)) clearHits(i);
         }
     }