diff --git a/include/verilated.h b/include/verilated.h
index 52d4e0976..db5c59052 100644
--- a/include/verilated.h
+++ b/include/verilated.h
@@ -104,9 +104,9 @@ class VerilatedModule {
 private:
     const char*		m_namep;	///< Module name
     VerilatedModule();				///< N/A, always use named constructor below
-    VerilatedModule(const VerilatedModule& );	///< N/A, no copying modules
+    VerilatedModule(const VerilatedModule& );	///< N/A, no copy constructor
 public:
-    VerilatedModule(const char* namep);	///< Create module with given hierarchy name
+    explicit VerilatedModule(const char* namep);	///< Create module with given hierarchy name
     ~VerilatedModule();
     const char* name() const { return m_namep; }	///< Return name of module
 };
diff --git a/include/verilated_cov.cpp b/include/verilated_cov.cpp
index 5fb6c938f..0e2cdb0f8 100644
--- a/include/verilated_cov.cpp
+++ b/include/verilated_cov.cpp
@@ -75,6 +75,7 @@ public:
     virtual vluint64_t count() const { return *m_countp; }
     virtual void zero() const { *m_countp = 0; }
     // CONSTRUCTORS
+    // cppcheck-suppress noExplicitConstructor
     VerilatedCoverItemSpec(T* countp) : m_countp(countp) { zero(); }
     virtual ~VerilatedCoverItemSpec() {}
 };
diff --git a/include/verilated_cov.h b/include/verilated_cov.h
index caa56259e..a66d12c41 100644
--- a/include/verilated_cov.h
+++ b/include/verilated_cov.h
@@ -84,6 +84,7 @@ template< class T> std::string vlCovCvtToStr (const T& t) {
 struct VlCovCvtToCStr {
     string m_str;
     // Casters
+    // cppcheck-suppress noExplicitConstructor
     template< class T> VlCovCvtToCStr (const T& t) {
 	ostringstream os; os<<t; m_str=os.str();
     }
diff --git a/include/verilated_save.h b/include/verilated_save.h
index 26eb86874..e4aec588e 100644
--- a/include/verilated_save.h
+++ b/include/verilated_save.h
@@ -48,6 +48,8 @@ protected:
 	m_bufp = new vluint8_t [bufferSize()];
 	m_cp = m_bufp;
     }
+private:
+    VerilatedSerialBase(const VerilatedSerialBase& );	///< N/A, no copy constructor
 public:
     // CREATORS
     virtual ~VerilatedSerialBase() {
diff --git a/include/verilated_vcd_c.h b/include/verilated_vcd_c.h
index 176dcad3b..a1db831bf 100644
--- a/include/verilated_vcd_c.h
+++ b/include/verilated_vcd_c.h
@@ -144,13 +144,15 @@ private:
 	return out + ((char)((code)%94+33));
     }
 
+    VerilatedVcd(const VerilatedVcd& );	///< N/A, no copy constructor
+
 protected:
     // METHODS
     void evcd(bool flag) { m_evcd = flag; }
 
 public:
     // CREATORS
-    VerilatedVcd(VerilatedVcdFile* filep=NULL);
+    explicit VerilatedVcd(VerilatedVcdFile* filep=NULL);
     ~VerilatedVcd();
 
     // ACCESSORS
@@ -399,7 +401,7 @@ class VerilatedVcdC {
     VerilatedVcd		m_sptrace;	///< Trace file being created
 public:
     // CONSTRUCTORS
-    VerilatedVcdC(VerilatedVcdFile* filep=NULL) : m_sptrace(filep) {}
+    explicit VerilatedVcdC(VerilatedVcdFile* filep=NULL) : m_sptrace(filep) {}
     ~VerilatedVcdC() {}
     // ACCESSORS
     /// Is file open?
diff --git a/include/verilated_vcd_sc.cpp b/include/verilated_vcd_sc.cpp
index b21f26d4f..14bda9943 100644
--- a/include/verilated_vcd_sc.cpp
+++ b/include/verilated_vcd_sc.cpp
@@ -30,6 +30,7 @@
 //--------------------------------------------------
 #if (SYSTEMC_VERSION>=20050714)
     // SystemC 2.1.v1
+// cppcheck-suppress unusedFunction
 void VerilatedVcdSc::write_comment (const std::string &) {}
 void VerilatedVcdSc::trace (const unsigned int &, const std::string &, const char **) {}
 
@@ -74,6 +75,7 @@ void VerilatedVcdSc::trace (const unsigned int &, const std::string &, const cha
 //--------------------------------------------------
 #elif (SYSTEMC_VERSION>20011000)
     // SystemC 2.0.1
+// cppcheck-suppress unusedFunction
 void VerilatedVcdSc::write_comment (const sc_string &) {}
 void VerilatedVcdSc::trace (const unsigned int &, const sc_string &, const char **) {}
 
@@ -116,6 +118,7 @@ void VerilatedVcdSc::trace (const unsigned int &, const sc_string &, const char
 //--------------------------------------------------
 #else
     // SystemC 1.2.1beta
+// cppcheck-suppress unusedFunction
 void VerilatedVcdSc::write_comment (const sc_string &) {}
 void VerilatedVcdSc::trace (const unsigned int &, const sc_string &, const char **) {}
 
diff --git a/include/verilated_vpi.cpp b/include/verilated_vpi.cpp
index 2110fcbdc..5d9e3baa9 100644
--- a/include/verilated_vpi.cpp
+++ b/include/verilated_vpi.cpp
@@ -431,6 +431,7 @@ void VerilatedVpiError::selfTest() {
 
 vpiHandle vpi_register_cb(p_cb_data cb_data_p) {
     _VL_VPI_ERROR_RESET(); // reset vpi error status
+    // cppcheck-suppress nullPointer
     if (VL_UNLIKELY(!cb_data_p)) {
         _VL_VPI_WARNING(__FILE__, __LINE__, "%s : callback data pointer is null", VL_FUNC);
         return NULL;
@@ -440,7 +441,7 @@ vpiHandle vpi_register_cb(p_cb_data cb_data_p) {
 	QData time = 0;
 	if (cb_data_p->time) time = _VL_SET_QII(cb_data_p->time->high, cb_data_p->time->low);
 	VerilatedVpioCb* vop = new VerilatedVpioCb(cb_data_p, VL_TIME_Q()+time);
-	VL_DEBUG_IF_PLI(VL_PRINTF("-vltVpi:  vpi_register_cb %d %p delay=%" VL_PRI64 "d\n",cb_data_p->reason,vop,time););
+	VL_DEBUG_IF_PLI(VL_PRINTF("-vltVpi:  vpi_register_cb %d %p delay=%" VL_PRI64 "u\n",cb_data_p->reason,vop,time););
 	VerilatedVpi::cbTimedAdd(vop);
 	return vop->castVpiHandle();
     }
@@ -1244,6 +1245,7 @@ void vpi_put_value_array(vpiHandle object, p_vpi_arrayvalue arrayvalue_p,
 // time processing
 
 void vpi_get_time(vpiHandle object, p_vpi_time time_p) {
+    // cppcheck-suppress nullPointer
     if (VL_UNLIKELY(!time_p)) {
 	_VL_VPI_WARNING(__FILE__, __LINE__, "Ignoring vpi_get_time with NULL value pointer");
 	return;
@@ -1303,6 +1305,7 @@ PLI_INT32 vpi_vprintf(PLI_BYTE8* formatp, va_list ap) {
 PLI_INT32 vpi_mcd_vprintf(PLI_UINT32 mcd, PLI_BYTE8 *format, va_list ap) {
     FILE* fp = VL_CVT_I_FP(mcd);
     _VL_VPI_ERROR_RESET(); // reset vpi error status
+    // cppcheck-suppress nullPointer
     if (VL_UNLIKELY(!fp)) return 0;
     int chars = vfprintf(fp, format, ap);
     return chars;
diff --git a/include/verilated_vpi.h b/include/verilated_vpi.h
index 4acc99a9f..ead2edf9c 100644
--- a/include/verilated_vpi.h
+++ b/include/verilated_vpi.h
@@ -130,7 +130,7 @@ public:
 class VerilatedVpioConst : public VerilatedVpio {
     vlsint32_t	m_num;
 public:
-    VerilatedVpioConst(vlsint32_t num) : m_num(num) {}
+    explicit VerilatedVpioConst(vlsint32_t num) : m_num(num) {}
     virtual ~VerilatedVpioConst() {}
     static inline VerilatedVpioConst* castp(vpiHandle h) { return dynamic_cast<VerilatedVpioConst*>((VerilatedVpio*)h); }
     virtual const vluint32_t type() { return vpiUndefined; }
@@ -141,7 +141,7 @@ class VerilatedVpioRange : public VerilatedVpio {
     const VerilatedRange* m_range;
     vlsint32_t                  m_iteration;
 public:
-    VerilatedVpioRange(const VerilatedRange* range) : m_range(range), m_iteration(0) {}
+    explicit VerilatedVpioRange(const VerilatedRange* range) : m_range(range), m_iteration(0) {}
     virtual ~VerilatedVpioRange() {}
     static inline VerilatedVpioRange* castp(vpiHandle h) { return dynamic_cast<VerilatedVpioRange*>((VerilatedVpio*)h); }
     virtual const vluint32_t type() { return vpiRange; }
@@ -163,7 +163,7 @@ public:
 class VerilatedVpioScope : public VerilatedVpio {
     const VerilatedScope*	m_scopep;
 public:
-    VerilatedVpioScope(const VerilatedScope* scopep)
+    explicit VerilatedVpioScope(const VerilatedScope* scopep)
 	: m_scopep(scopep) {}
     virtual ~VerilatedVpioScope() {}
     static inline VerilatedVpioScope* castp(vpiHandle h) { return dynamic_cast<VerilatedVpioScope*>((VerilatedVpio*)h); }
@@ -255,7 +255,7 @@ class VerilatedVpioVarIter : public VerilatedVpio {
     VerilatedVarNameMap::iterator m_it;
     bool m_started;
 public:
-    VerilatedVpioVarIter(const VerilatedScope* scopep)
+    explicit VerilatedVpioVarIter(const VerilatedScope* scopep)
 	: m_scopep(scopep), m_started(false) {  }
     virtual ~VerilatedVpioVarIter() {}
     static inline VerilatedVpioVarIter* castp(vpiHandle h) { return dynamic_cast<VerilatedVpioVarIter*>((VerilatedVpio*)h); }
diff --git a/src/V3Active.cpp b/src/V3Active.cpp
index 5a215bf02..2599eb696 100644
--- a/src/V3Active.cpp
+++ b/src/V3Active.cpp
@@ -421,7 +421,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    ActiveVisitor(AstNetlist* nodep) {
+    explicit ActiveVisitor(AstNetlist* nodep) {
 	m_scopeFinalp = NULL;
 	m_itemCombo = false;
 	m_itemSequent = false;
diff --git a/src/V3ActiveTop.cpp b/src/V3ActiveTop.cpp
index 264876f38..af89730e0 100644
--- a/src/V3ActiveTop.cpp
+++ b/src/V3ActiveTop.cpp
@@ -147,7 +147,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    ActiveTopVisitor(AstNetlist* nodep) {
+    explicit ActiveTopVisitor(AstNetlist* nodep) {
 	m_topscopep = NULL;
 	nodep->accept(*this);
     }
diff --git a/src/V3Assert.cpp b/src/V3Assert.cpp
index 7b7d96a1f..29bf6a53c 100644
--- a/src/V3Assert.cpp
+++ b/src/V3Assert.cpp
@@ -317,7 +317,7 @@ private:
     }
 public:
     // CONSTRUCTORS
-    AssertVisitor(AstNetlist* nodep) {
+    explicit AssertVisitor(AstNetlist* nodep) {
 	m_beginp = NULL;
 	m_modp = NULL;
 	// Process
diff --git a/src/V3AssertPre.cpp b/src/V3AssertPre.cpp
index c4fa770d8..ba9dacc7a 100644
--- a/src/V3AssertPre.cpp
+++ b/src/V3AssertPre.cpp
@@ -122,7 +122,7 @@ private:
 
 public:
     // CONSTRUCTORS
-    AssertPreVisitor(AstNetlist* nodep) {
+    explicit AssertPreVisitor(AstNetlist* nodep) {
 	m_seniDefaultp = NULL;
 	clearAssertInfo();
 	// Process
diff --git a/src/V3Ast.h b/src/V3Ast.h
index 6e8c446c0..0d17f4ce1 100644
--- a/src/V3Ast.h
+++ b/src/V3Ast.h
@@ -53,6 +53,7 @@ public:
     enum en m_e;
     // cppcheck-suppress uninitVar  // responsiblity of each subclass
     inline AstType () {}
+    // cppcheck-suppress noExplicitConstructor
     inline AstType (en _e) : m_e(_e) {}
     explicit inline AstType (int _e) : m_e(static_cast<en>(_e)) {}
     operator en () const { return m_e; }
@@ -87,7 +88,9 @@ public:
 	return names[m_e];
     };
     inline AstNumeric () : m_e(UNSIGNED) {}
+    // cppcheck-suppress noExplicitConstructor
     inline AstNumeric (en _e) : m_e(_e) {}
+    // cppcheck-suppress noExplicitConstructor
     inline AstNumeric (VSignedState signst) {
 	if (signst==signedst_UNSIGNED) m_e=UNSIGNED;
 	else if (signst==signedst_SIGNED) m_e=SIGNED;
@@ -121,6 +124,7 @@ public:
     };
     enum en m_e;
     inline AstPragmaType () : m_e(ILLEGAL) {}
+    // cppcheck-suppress noExplicitConstructor
     inline AstPragmaType (en _e) : m_e(_e) {}
     explicit inline AstPragmaType (int _e) : m_e(static_cast<en>(_e)) {}
     operator en () const { return m_e; }
@@ -144,6 +148,7 @@ public:
     };
     enum en m_e;
     inline AstCFuncType () : m_e(FT_NORMAL) {}
+    // cppcheck-suppress noExplicitConstructor
     inline AstCFuncType (en _e) : m_e(_e) {}
     explicit inline AstCFuncType (int _e) : m_e(static_cast<en>(_e)) {}
     operator en () const { return m_e; }
@@ -212,6 +217,7 @@ public:
 	return names[m_e];
     };
     inline AstEdgeType () : m_e(ET_ILLEGAL) {}
+    // cppcheck-suppress noExplicitConstructor
     inline AstEdgeType (en _e) : m_e(_e) {}
     explicit inline AstEdgeType (int _e) : m_e(static_cast<en>(_e)) {}
     operator en () const { return m_e; }
@@ -279,6 +285,7 @@ public:
 	return names[m_e];
     };
     inline AstAttrType () : m_e(ILLEGAL) {}
+    // cppcheck-suppress noExplicitConstructor
     inline AstAttrType (en _e) : m_e(_e) {}
     explicit inline AstAttrType (int _e) : m_e(static_cast<en>(_e)) {}
     operator en () const { return m_e; }
@@ -338,6 +345,7 @@ public:
 	UASSERT(0==strcmp(AstBasicDTypeKwd(_ENUM_MAX).dpiType()," MAX"),"Enum array mismatch");
     }
     inline AstBasicDTypeKwd () : m_e(UNKNOWN) {}
+    // cppcheck-suppress noExplicitConstructor
     inline AstBasicDTypeKwd (en _e) : m_e(_e) {}
     explicit inline AstBasicDTypeKwd (int _e) : m_e(static_cast<en>(_e)) {}
     operator en () const { return m_e; }
@@ -432,6 +440,7 @@ public:
     };
     enum en m_e;
     inline AstVarType () : m_e(UNKNOWN) {}
+    // cppcheck-suppress noExplicitConstructor
     inline AstVarType (en _e) : m_e(_e) {}
     explicit inline AstVarType (int _e) : m_e(static_cast<en>(_e)) {}
     operator en () const { return m_e; }
@@ -469,6 +478,7 @@ public:
     enum en m_e;
     // CONSTRUCTOR - note defaults to *UNKNOWN*
     inline AstBranchPred () : m_e(BP_UNKNOWN) {}
+    // cppcheck-suppress noExplicitConstructor
     inline AstBranchPred (en _e) : m_e(_e) {}
     explicit inline AstBranchPred (int _e) : m_e(static_cast<en>(_e)) {}
     operator en () const { return m_e; }
@@ -500,6 +510,7 @@ public:
     enum en m_e;
     // CONSTRUCTOR - note defaults to *UNKNOWN*
     inline AstVarAttrClocker () : m_e(CLOCKER_UNKNOWN) {}
+    // cppcheck-suppress noExplicitConstructor
     inline AstVarAttrClocker (en _e) : m_e(_e) {}
     explicit inline AstVarAttrClocker (int _e) : m_e(static_cast<en>(_e)) {}
     operator en () const { return m_e; }
@@ -530,6 +541,7 @@ public:
     };
     enum en m_e;
     inline VAlwaysKwd () : m_e(ALWAYS) {}
+    // cppcheck-suppress noExplicitConstructor
     inline VAlwaysKwd (en _e) : m_e(_e) {}
     explicit inline VAlwaysKwd (int _e) : m_e(static_cast<en>(_e)) {}
     operator en () const { return m_e; }
@@ -554,6 +566,7 @@ public:
     };
     enum en m_e;
     inline VCaseType () : m_e(CT_CASE) {}
+    // cppcheck-suppress noExplicitConstructor
     inline VCaseType (en _e) : m_e(_e) {}
     explicit inline VCaseType (int _e) : m_e(static_cast<en>(_e)) {}
     operator en () const { return m_e; }
@@ -576,6 +589,7 @@ public:
     };
     enum en m_e;
     inline AstDisplayType () : m_e(DT_DISPLAY) {}
+    // cppcheck-suppress noExplicitConstructor
     inline AstDisplayType (en _e) : m_e(_e) {}
     explicit inline AstDisplayType (int _e) : m_e(static_cast<en>(_e)) {}
     operator en () const { return m_e; }
@@ -600,6 +614,7 @@ public:
     };
     enum en m_e;
     inline AstParseRefExp() : m_e(PX_NONE) {}
+    // cppcheck-suppress noExplicitConstructor
     inline AstParseRefExp (en _e) : m_e(_e) {}
     explicit inline AstParseRefExp (int _e) : m_e(static_cast<en>(_e)) {}
     operator en () const { return m_e; }
@@ -897,16 +912,19 @@ public:
     // CREATORS
     class Illegal {};		// for creator type-overload selection
     class FullValue {};		// for creator type-overload selection
-    V3Hash(Illegal) { m_both=0; }
+    explicit V3Hash(Illegal) { m_both=0; }
     // Saving and restoring inside a userp
-    V3Hash(AstNUser* up) { m_both=up->castInt(); }
+    explicit V3Hash(AstNUser* up) { m_both=up->castInt(); }
     V3Hash operator+= (const V3Hash& rh) {
 	setBoth(depth()+rh.depth(), (hshval()*31+rh.hshval()));
 	return *this; };
     // Creating from raw data (sameHash functions)
     V3Hash() { setBoth(1,0); }
+    // cppcheck-suppress noExplicitConstructor
     V3Hash(uint32_t val) { setBoth(1,val); }
+    // cppcheck-suppress noExplicitConstructor
     V3Hash(const void* vp) { setBoth(1,cvtToHash(vp)); }
+    // cppcheck-suppress noExplicitConstructor
     V3Hash(const string& name);
     V3Hash(V3Hash h1, V3Hash h2) {
 	setBoth(1,h1.hshval()*31+h2.hshval()); }
@@ -991,7 +1009,7 @@ public:
 protected:
     // CONSTUCTORS
     AstNode() {init(); }
-    AstNode(FileLine* fileline) {init(); m_fileline = fileline; }
+    explicit AstNode(FileLine* fileline) {init(); m_fileline = fileline; }
     virtual AstNode* clone() = 0;	// Generally, cloneTree is what you want instead
     virtual void cloneRelink() {}
     void 	cloneRelinkTree();
@@ -1274,7 +1292,7 @@ inline void AstNRelinker::relink(AstNode* newp) { newp->AstNode::relink(this); }
 class AstNodeMath : public AstNode {
     // Math -- anything that's part of an expression tree
 public:
-    AstNodeMath(FileLine* fl)
+    explicit AstNodeMath(FileLine* fl)
 	: AstNode(fl) {}
     ASTNODE_BASE_FUNCS(NodeMath)
     // METHODS
@@ -1291,7 +1309,7 @@ public:
 class AstNodeTermop : public AstNodeMath {
     // Terminal operator -- a operator with no "inputs"
 public:
-    AstNodeTermop(FileLine* fl)
+    explicit AstNodeTermop(FileLine* fl)
 	: AstNodeMath(fl) {}
     ASTNODE_BASE_FUNCS(NodeTermop)
     // Know no children, and hot function, so skip iterator for speed
@@ -1435,7 +1453,7 @@ public:
 class AstNodeStmt : public AstNode {
     // Statement -- anything that's directly under a function
 public:
-    AstNodeStmt(FileLine* fl)
+    explicit AstNodeStmt(FileLine* fl)
 	: AstNode(fl) {}
     ASTNODE_BASE_FUNCS(NodeStmt)
     // METHODS
@@ -1525,7 +1543,7 @@ public:
 class AstNodeSenItem : public AstNode {
     // An AstSenItem or AstSenGate
 public:
-    AstNodeSenItem(FileLine* fl) : AstNode(fl) {}
+    explicit AstNodeSenItem(FileLine* fl) : AstNode(fl) {}
     ASTNODE_BASE_FUNCS(NodeSenItem)
     virtual bool isClocked() const = 0;
     virtual bool isCombo() const = 0;
@@ -1612,7 +1630,7 @@ private:
     static int	s_uniqueNum;	// Unique number assigned to each dtype during creation for IEEE matching
 public:
     // CONSTRUCTORS
-    AstNodeDType(FileLine* fl) : AstNode(fl) {
+    explicit AstNodeDType(FileLine* fl) : AstNode(fl) {
 	m_width=0; m_widthMin=0; m_generic=false;
     }
     ASTNODE_BASE_FUNCS(NodeDType)
@@ -1701,7 +1719,7 @@ private:
     AstNodeDType*	m_refDTypep;	// Elements of this type (after widthing)
     AstNode*	rangenp() const { return op2p(); }	// op2 = Array(s) of variable
 public:
-    AstNodeArrayDType(FileLine* fl) : AstNodeDType(fl) {
+    explicit AstNodeArrayDType(FileLine* fl) : AstNodeDType(fl) {
 	m_refDTypep = NULL;
     }
     ASTNODE_BASE_FUNCS(NodeArrayDType)
diff --git a/src/V3AstNodes.h b/src/V3AstNodes.h
index 3864abb21..05916c980 100644
--- a/src/V3AstNodes.h
+++ b/src/V3AstNodes.h
@@ -2604,7 +2604,7 @@ public:
 
 class AstBreak : public AstNodeStmt {
 public:
-    AstBreak(FileLine* fileline)
+    explicit AstBreak(FileLine* fileline)
 	: AstNodeStmt (fileline) {}
     ASTNODE_NODE_FUNCS(Break, BREAK)
     virtual string verilogKwd() const { return "break"; };
@@ -2614,7 +2614,7 @@ public:
 
 class AstContinue : public AstNodeStmt {
 public:
-    AstContinue(FileLine* fileline)
+    explicit AstContinue(FileLine* fileline)
 	: AstNodeStmt (fileline) {}
     ASTNODE_NODE_FUNCS(Continue, CONTINUE)
     virtual string verilogKwd() const { return "continue"; };
@@ -2907,7 +2907,7 @@ public:
 
 class AstStop : public AstNodeStmt {
 public:
-    AstStop(FileLine* fl)
+    explicit AstStop(FileLine* fl)
 	: AstNodeStmt(fl) {}
     ASTNODE_NODE_FUNCS(Stop, STOP)
     virtual bool isGateOptimizable() const { return false; }
@@ -2923,7 +2923,7 @@ public:
 
 class AstFinish : public AstNodeStmt {
 public:
-    AstFinish(FileLine* fl)
+    explicit AstFinish(FileLine* fl)
 	: AstNodeStmt(fl) {}
     ASTNODE_NODE_FUNCS(Finish, FINISH)
     virtual bool isGateOptimizable() const { return false; }
@@ -3072,7 +3072,7 @@ private:
     string scopeNameFormatter(AstText* textp) const;
     string scopePrettyNameFormatter(AstText* textp) const;
 public:
-    AstScopeName(FileLine* fl) : AstNodeMath(fl), m_dpiExport(false) {
+    explicit AstScopeName(FileLine* fl) : AstNodeMath(fl), m_dpiExport(false) {
 	dtypeSetUInt64(); }
     ASTNODE_NODE_FUNCS(ScopeName, SCOPENAME)
     virtual V3Hash sameHash() const { return V3Hash(); }
@@ -3122,7 +3122,7 @@ private:
 public:
     AstRand(FileLine* fl, AstNodeDType* dtp, bool reset) : AstNodeTermop(fl) {
 	dtypep(dtp); m_reset=reset; }
-    AstRand(FileLine* fl) : AstNodeTermop(fl), m_reset(false) { }
+    explicit AstRand(FileLine* fl) : AstNodeTermop(fl), m_reset(false) { }
     ASTNODE_NODE_FUNCS(Rand, RAND)
     virtual string emitVerilog() { return "%f$random"; }
     virtual string emitC() {
@@ -3139,7 +3139,7 @@ public:
 
 class AstTime : public AstNodeTermop {
 public:
-    AstTime(FileLine* fl)	: AstNodeTermop(fl) {
+    explicit AstTime(FileLine* fl) : AstNodeTermop(fl) {
 	dtypeSetUInt64(); }
     ASTNODE_NODE_FUNCS(Time, TIME)
     virtual string emitVerilog() { return "%f$time"; }
@@ -3154,7 +3154,7 @@ public:
 
 class AstTimeD : public AstNodeTermop {
 public:
-    AstTimeD(FileLine* fl)	: AstNodeTermop(fl) {
+    explicit AstTimeD(FileLine* fl) : AstNodeTermop(fl) {
 	dtypeSetDouble(); }
     ASTNODE_NODE_FUNCS(TimeD, TIMED)
     virtual string emitVerilog() { return "%f$realtime"; }
@@ -5082,7 +5082,7 @@ class AstTypeTable : public AstNode {
     typedef map<VBasicTypeKey,AstBasicDType*> DetailedMap;
     DetailedMap m_detailedMap;
 public:
-    AstTypeTable(FileLine* fl) : AstNode(fl) {
+    explicit AstTypeTable(FileLine* fl) : AstNode(fl) {
 	for (int i=0; i<AstBasicDTypeKwd::_ENUM_MAX; ++i) m_basicps[i] = NULL;
     }
     ASTNODE_NODE_FUNCS(TypeTable, TYPETABLE)
diff --git a/src/V3Branch.cpp b/src/V3Branch.cpp
index df0ab7699..d5c02fb97 100644
--- a/src/V3Branch.cpp
+++ b/src/V3Branch.cpp
@@ -128,7 +128,7 @@ private:
 
 public:
     // CONSTUCTORS
-    BranchVisitor(AstNetlist* nodep) {
+    explicit BranchVisitor(AstNetlist* nodep) {
 	reset();
 	nodep->iterateChildren(*this);
 	calc_tasks();
diff --git a/src/V3Broken.cpp b/src/V3Broken.cpp
index abc7fee87..5f6e81206 100644
--- a/src/V3Broken.cpp
+++ b/src/V3Broken.cpp
@@ -197,7 +197,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    BrokenMarkVisitor(AstNetlist* nodep) {
+    explicit BrokenMarkVisitor(AstNetlist* nodep) {
 	nodep->accept(*this);
     }
     virtual ~BrokenMarkVisitor() {}
@@ -241,7 +241,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    BrokenCheckVisitor(AstNetlist* nodep) {
+    explicit BrokenCheckVisitor(AstNetlist* nodep) {
 	nodep->accept(*this);
     }
     virtual ~BrokenCheckVisitor() {}
diff --git a/src/V3Case.cpp b/src/V3Case.cpp
index 01cef885d..bc6c26cf1 100644
--- a/src/V3Case.cpp
+++ b/src/V3Case.cpp
@@ -112,7 +112,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    CaseLintVisitor(AstNodeCase* nodep) {
+    explicit CaseLintVisitor(AstNodeCase* nodep) {
 	m_caseExprp = NULL;
 	nodep->accept(*this);
     }
@@ -475,7 +475,7 @@ private:
 
 public:
     // CONSTUCTORS
-    CaseVisitor(AstNetlist* nodep) {
+    explicit CaseVisitor(AstNetlist* nodep) {
 	m_caseNoOverlapsAllCovered = false;
 	nodep->accept(*this);
     }
diff --git a/src/V3Cast.cpp b/src/V3Cast.cpp
index baf77c5c0..cab7b8a6a 100644
--- a/src/V3Cast.cpp
+++ b/src/V3Cast.cpp
@@ -176,7 +176,7 @@ private:
 
 public:
     // CONSTUCTORS
-    CastVisitor(AstNetlist* nodep) {
+    explicit CastVisitor(AstNetlist* nodep) {
 	nodep->accept(*this);
     }
     virtual ~CastVisitor() {}
diff --git a/src/V3Cdc.cpp b/src/V3Cdc.cpp
index f704fd738..1808daee6 100644
--- a/src/V3Cdc.cpp
+++ b/src/V3Cdc.cpp
@@ -184,7 +184,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    CdcWidthVisitor(AstNode* nodep) {
+    explicit CdcWidthVisitor(AstNode* nodep) {
 	m_maxLineno = 0;
 	m_maxFilenameLen = 0;
 	nodep->accept(*this);
@@ -726,7 +726,7 @@ private:
 
 public:
     // CONSTUCTORS
-    CdcVisitor(AstNode* nodep) {
+    explicit CdcVisitor(AstNode* nodep) {
 	m_logicVertexp = NULL;
 	m_scopep = NULL;
 	m_modp = NULL;
diff --git a/src/V3Clean.cpp b/src/V3Clean.cpp
index 192c245d5..8afab109f 100644
--- a/src/V3Clean.cpp
+++ b/src/V3Clean.cpp
@@ -280,7 +280,7 @@ private:
 
 public:
     // CONSTUCTORS
-    CleanVisitor(AstNetlist* nodep) {
+    explicit CleanVisitor(AstNetlist* nodep) {
 	nodep->accept(*this);
     }
     virtual ~CleanVisitor() {}
diff --git a/src/V3ClkGater.cpp b/src/V3ClkGater.cpp
index b9945a54a..de7f72dd8 100644
--- a/src/V3ClkGater.cpp
+++ b/src/V3ClkGater.cpp
@@ -66,7 +66,7 @@ class GaterVarVertex;
 class GaterVertex : public V3GraphVertex {
     static uint32_t s_rankNum;
 public:
-    GaterVertex(V3Graph* graphp)
+    explicit GaterVertex(V3Graph* graphp)
 	: V3GraphVertex(graphp) {
 	s_rankNum++; rank(s_rankNum);
     }
@@ -79,7 +79,7 @@ uint32_t GaterVertex::s_rankNum = 0;
 
 class GaterHeadVertex : public GaterVertex {
 public:
-    GaterHeadVertex(V3Graph* graphp)
+    explicit GaterHeadVertex(V3Graph* graphp)
 	: GaterVertex(graphp) {}
     virtual ~GaterHeadVertex() {}
     virtual int typeNum() const { return __LINE__; }  // C++ typeof() equivelent
@@ -89,7 +89,7 @@ public:
 
 class GaterPliVertex : public GaterVertex {
 public:
-    GaterPliVertex(V3Graph* graphp)
+    explicit GaterPliVertex(V3Graph* graphp)
 	: GaterVertex(graphp) {}
     virtual ~GaterPliVertex() {}
     virtual int typeNum() const { return __LINE__; }  // C++ typeof() equivelent
@@ -217,7 +217,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    GaterCondVisitor(AstNode* nodep) {
+    explicit GaterCondVisitor(AstNode* nodep) {
 	m_isSimple = true;
 	nodep->accept(*this);
     }
@@ -878,7 +878,7 @@ class GaterVisitor : public GaterBaseVisitor {
 
 public:
     // CONSTUCTORS
-    GaterVisitor(AstNode* nodep) {
+    explicit GaterVisitor(AstNode* nodep) {
 	// AstAlways visitor does the real work, so most zeroing needs to be in clear()
 	clear();
 	nodep->accept(*this);
diff --git a/src/V3Clock.cpp b/src/V3Clock.cpp
index ef1c08e39..36a3d1327 100644
--- a/src/V3Clock.cpp
+++ b/src/V3Clock.cpp
@@ -386,7 +386,7 @@ private:
 
 public:
     // CONSTUCTORS
-    ClockVisitor(AstNetlist* nodep) {
+    explicit ClockVisitor(AstNetlist* nodep) {
 	m_modp=NULL; m_activep=NULL;
 	m_evalFuncp = NULL;
 	m_topScopep=NULL;
diff --git a/src/V3Combine.cpp b/src/V3Combine.cpp
index 9ee44d537..ed412d38d 100644
--- a/src/V3Combine.cpp
+++ b/src/V3Combine.cpp
@@ -169,7 +169,7 @@ private:
     }
 public:
     // CONSTRUCTORS
-    CombMarkVisitor(AstNode* nodep) {
+    explicit CombMarkVisitor(AstNode* nodep) {
 	nodep->accept(*this);
     }
     virtual ~CombMarkVisitor() {}
@@ -457,7 +457,7 @@ private:
 
 public:
     // CONSTUCTORS
-    CombineVisitor(AstNetlist* nodep) {
+    explicit CombineVisitor(AstNetlist* nodep) {
 	m_modp=NULL;
 	m_funcp = NULL;
 	m_state = STATE_IDLE;
diff --git a/src/V3Const.cpp b/src/V3Const.cpp
index a761be478..3b5125364 100644
--- a/src/V3Const.cpp
+++ b/src/V3Const.cpp
@@ -54,7 +54,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    ConstVarMarkVisitor(AstNode* nodep) {
+    explicit ConstVarMarkVisitor(AstNode* nodep) {
 	AstNode::user4ClearTree();  // Check marked InUse before we're called
 	nodep->accept(*this);
     }
@@ -76,7 +76,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    ConstVarFindVisitor(AstNode* nodep) {
+    explicit ConstVarFindVisitor(AstNode* nodep) {
 	m_found = false;
 	nodep->iterateAndNext(*this, NULL);
     }
@@ -2292,7 +2292,7 @@ public:
     };
 
     // CONSTUCTORS
-    ConstVisitor(ProcMode pmode) {
+    explicit ConstVisitor(ProcMode pmode) {
 	m_params = false;
 	m_required = false;
 	m_doExpensive = false;
diff --git a/src/V3Coverage.cpp b/src/V3Coverage.cpp
index b5ad49408..414336391 100644
--- a/src/V3Coverage.cpp
+++ b/src/V3Coverage.cpp
@@ -378,7 +378,7 @@ private:
 
 public:
     // CONSTUCTORS
-    CoverageVisitor(AstNetlist* rootp) {
+    explicit CoverageVisitor(AstNetlist* rootp) {
 	// Operate on all modules
 	m_checkBlock = true;
 	m_beginHier = "";
diff --git a/src/V3CoverageJoin.cpp b/src/V3CoverageJoin.cpp
index 8a0010e9f..435ad416e 100644
--- a/src/V3CoverageJoin.cpp
+++ b/src/V3CoverageJoin.cpp
@@ -121,7 +121,7 @@ private:
 
 public:
     // CONSTUCTORS
-    CoverageJoinVisitor(AstNetlist* nodep) {
+    explicit CoverageJoinVisitor(AstNetlist* nodep) {
 	nodep->accept(*this);
     }
     virtual ~CoverageJoinVisitor() {
diff --git a/src/V3Dead.cpp b/src/V3Dead.cpp
index ac2e20faf..e06ab77dc 100644
--- a/src/V3Dead.cpp
+++ b/src/V3Dead.cpp
@@ -58,7 +58,7 @@ private:
     }
 public:
     // CONSTRUCTORS
-    DeadModVisitor(AstNodeModule* nodep) {
+    explicit DeadModVisitor(AstNodeModule* nodep) {
 	nodep->accept(*this);
     }
     virtual ~DeadModVisitor() {}
diff --git a/src/V3Delayed.cpp b/src/V3Delayed.cpp
index 178b9bf0d..cd5cfd392 100644
--- a/src/V3Delayed.cpp
+++ b/src/V3Delayed.cpp
@@ -450,7 +450,7 @@ private:
 
 public:
     // CONSTUCTORS
-    DelayedVisitor(AstNetlist* nodep) {
+    explicit DelayedVisitor(AstNetlist* nodep) {
 	m_inDly = false;
 	m_activep=NULL;
 	m_cfuncp=NULL;
diff --git a/src/V3Depth.cpp b/src/V3Depth.cpp
index a5f734800..0d36f74a9 100644
--- a/src/V3Depth.cpp
+++ b/src/V3Depth.cpp
@@ -157,7 +157,7 @@ private:
 
 public:
     // CONSTUCTORS
-    DepthVisitor(AstNetlist* nodep) {
+    explicit DepthVisitor(AstNetlist* nodep) {
 	m_modp=NULL;
 	m_funcp=NULL;
 	m_stmtp=NULL;
diff --git a/src/V3DepthBlock.cpp b/src/V3DepthBlock.cpp
index 61be83491..03ff3ca7b 100644
--- a/src/V3DepthBlock.cpp
+++ b/src/V3DepthBlock.cpp
@@ -125,7 +125,7 @@ private:
 
 public:
     // CONSTUCTORS
-    DepthBlockVisitor(AstNetlist* nodep) {
+    explicit DepthBlockVisitor(AstNetlist* nodep) {
 	m_modp=NULL;
 	m_depth=0;
 	//
diff --git a/src/V3Descope.cpp b/src/V3Descope.cpp
index 3d91b3360..20eb46563 100644
--- a/src/V3Descope.cpp
+++ b/src/V3Descope.cpp
@@ -247,7 +247,7 @@ private:
     }
 public:
     // CONSTRUCTORS
-    DescopeVisitor(AstNetlist* nodep) {
+    explicit DescopeVisitor(AstNetlist* nodep) {
 	m_modp = NULL;
 	m_scopep = NULL;
 	m_needThis = false;
diff --git a/src/V3EmitC.cpp b/src/V3EmitC.cpp
index 618ab77d5..63d32492d 100644
--- a/src/V3EmitC.cpp
+++ b/src/V3EmitC.cpp
@@ -656,7 +656,7 @@ public:
 	    }
 	} else if (nodep->isQuad()) {
 	    vluint64_t num = nodep->toUQuad();
-	    if (num<10) ofp()->printf("VL_ULL(%" VL_PRI64 "d)", num);
+	    if (num<10) ofp()->printf("VL_ULL(%" VL_PRI64 "u)", num);
 	    else ofp()->printf("VL_ULL(0x%" VL_PRI64 "x)", num);
 	} else {
 	    uint32_t num = nodep->toUInt();
@@ -2434,7 +2434,7 @@ class EmitCTrace : EmitCStmts {
     }
 
 public:
-    EmitCTrace(bool slow) {
+    explicit EmitCTrace(bool slow) {
 	m_funcp = NULL;
 	m_slow = slow;
     }
diff --git a/src/V3EmitCBase.h b/src/V3EmitCBase.h
index df84d2e47..38a361f0a 100644
--- a/src/V3EmitCBase.h
+++ b/src/V3EmitCBase.h
@@ -106,7 +106,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    EmitCBaseCounterVisitor(AstNode* nodep) {
+    explicit EmitCBaseCounterVisitor(AstNode* nodep) {
 	m_count = 0;
 	nodep->accept(*this);
     }
diff --git a/src/V3EmitCInlines.cpp b/src/V3EmitCInlines.cpp
index 93dab1f1c..15eff33a0 100644
--- a/src/V3EmitCInlines.cpp
+++ b/src/V3EmitCInlines.cpp
@@ -71,7 +71,7 @@ class EmitCInlines : EmitCBaseVisitor {
     //---------------------------------------
     // ACCESSORS
 public:
-    EmitCInlines(AstNetlist* nodep) {
+    explicit EmitCInlines(AstNetlist* nodep) {
 	nodep->accept(*this);
 	if (v3Global.needHInlines()) {
 	    emitInt();
diff --git a/src/V3EmitCSyms.cpp b/src/V3EmitCSyms.cpp
index 88a010ad2..0dd453b7f 100644
--- a/src/V3EmitCSyms.cpp
+++ b/src/V3EmitCSyms.cpp
@@ -244,7 +244,7 @@ class EmitCSyms : EmitCBaseVisitor {
     //---------------------------------------
     // ACCESSORS
 public:
-    EmitCSyms(AstNetlist* nodep) {
+    explicit EmitCSyms(AstNetlist* nodep) {
 	m_funcp = NULL;
 	m_modp = NULL;
 	m_coverBins = 0;
diff --git a/src/V3EmitMk.cpp b/src/V3EmitMk.cpp
index 4d1f5add9..34deab6fd 100644
--- a/src/V3EmitMk.cpp
+++ b/src/V3EmitMk.cpp
@@ -234,7 +234,7 @@ public:
     }
 
 public:
-    EmitMkVisitor(AstNetlist*) {
+    explicit EmitMkVisitor(AstNetlist*) {
 	emitClassMake();
 	emitOverallMake();
     }
diff --git a/src/V3EmitV.cpp b/src/V3EmitV.cpp
index 23a30f69b..ebfcce8b7 100644
--- a/src/V3EmitV.cpp
+++ b/src/V3EmitV.cpp
@@ -589,7 +589,7 @@ class EmitVBaseVisitor : public EmitCBaseVisitor {
     }
 
 public:
-    EmitVBaseVisitor(AstSenTree* domainp=NULL) {   // Domain for printing one a ALWAYS under a ACTIVE
+    explicit EmitVBaseVisitor(AstSenTree* domainp=NULL) {   // Domain for printing one a ALWAYS under a ACTIVE
 	m_suppressSemi = false;
 	m_sensesp = domainp;
     }
diff --git a/src/V3Error.h b/src/V3Error.h
index aced98bdf..38bcf42fd 100644
--- a/src/V3Error.h
+++ b/src/V3Error.h
@@ -104,8 +104,9 @@ public:
     };
     enum en m_e;
     inline V3ErrorCode () : m_e(EC_MIN) {}
+    // cppcheck-suppress noExplicitConstructor
     inline V3ErrorCode (en _e) : m_e(_e) {}
-    V3ErrorCode (const char* msgp);	// Matching code or ERROR
+    explicit V3ErrorCode (const char* msgp);	// Matching code or ERROR
     explicit inline V3ErrorCode (int _e) : m_e(static_cast<en>(_e)) {}
     operator en () const { return m_e; }
     const char* ascii() const {
diff --git a/src/V3Expand.cpp b/src/V3Expand.cpp
index d415641b3..0935b1297 100644
--- a/src/V3Expand.cpp
+++ b/src/V3Expand.cpp
@@ -921,7 +921,7 @@ private:
 
 public:
     // CONSTUCTORS
-    ExpandVisitor(AstNetlist* nodep) {
+    explicit ExpandVisitor(AstNetlist* nodep) {
 	m_stmtp=NULL;
 	nodep->accept(*this);
     }
diff --git a/src/V3File.cpp b/src/V3File.cpp
index be4bf36f7..b32d9e885 100644
--- a/src/V3File.cpp
+++ b/src/V3File.cpp
@@ -363,6 +363,7 @@ private:
 	}
 	return out;
     }
+    // cppcheck-suppress unusedFunction
     string readFilterLine() {
 	// Slow, but we don't need it much
 	UINFO(9,"readFilterLine\n");
@@ -380,6 +381,7 @@ private:
 	UINFO(6,"filter-line-in: "<<line);
 	return line;
     }
+    // cppcheck-suppress unusedFunction
     void writeFilter(const string& out) {
 	if (debug()>=6) { UINFO(6,"filter-out: "<<out); if (out[out.length()-1]!='\n') cout<<endl; }
 	if (!m_pid) { v3error("--pipe-filter: write to closed file\n"); m_readEof = true; stop(); }
@@ -521,7 +523,7 @@ protected:
 	return out;
     }
     // CONSTRUCTORS
-    V3InFilterImp(const string& command) {
+    explicit V3InFilterImp(const string& command) {
 	m_readEof = false;
 	m_pid = 0;
 	m_pidExited = false;
diff --git a/src/V3File.h b/src/V3File.h
index 520f78ee4..138196d16 100644
--- a/src/V3File.h
+++ b/src/V3File.h
@@ -77,6 +77,7 @@ class V3InFilterImp;
 
 class V3InFilter {
     V3InFilterImp* m_impp;
+    V3InFilter(const V3InFilter&); ///< N/A, no copy constructor
 public:
     // TYPES
     typedef list<string> StrList;
@@ -86,7 +87,7 @@ public:
     bool readWholefile(const string& filename, StrList& outl);
 
     // CONSTRUCTORS
-    V3InFilter(const string& command);
+    explicit V3InFilter(const string& command);
     ~V3InFilter();
 };
 
@@ -183,7 +184,7 @@ private:
 class V3OutCFile : public V3OutFile {
     int		m_private;
 public:
-    V3OutCFile(const string& filename) : V3OutFile(filename, V3OutFormatter::LA_C) {
+    explicit V3OutCFile(const string& filename) : V3OutFile(filename, V3OutFormatter::LA_C) {
 	resetPrivate();
     }
     virtual ~V3OutCFile() {}
@@ -208,7 +209,7 @@ public:
 
 class V3OutScFile : public V3OutCFile {
 public:
-    V3OutScFile(const string& filename) : V3OutCFile(filename) {}
+    explicit V3OutScFile(const string& filename) : V3OutCFile(filename) {}
     virtual ~V3OutScFile() {}
     virtual void putsHeader() { puts("// Verilated -*- SystemC -*-\n"); }
     virtual void putsIntTopInclude() {
@@ -219,7 +220,7 @@ public:
 
 class V3OutSpFile : public V3OutCFile {
 public:
-    V3OutSpFile(const string& filename) : V3OutCFile(filename) {}
+    explicit V3OutSpFile(const string& filename) : V3OutCFile(filename) {}
     virtual ~V3OutSpFile() {}
     virtual void putsHeader() { puts("// Verilated -*- SystemC -*-\n"); }
     virtual void putsIntTopInclude() {
@@ -230,21 +231,21 @@ public:
 
 class V3OutVFile : public V3OutFile {
 public:
-    V3OutVFile(const string& filename) : V3OutFile(filename, V3OutFormatter::LA_VERILOG) {}
+    explicit V3OutVFile(const string& filename) : V3OutFile(filename, V3OutFormatter::LA_VERILOG) {}
     virtual ~V3OutVFile() {}
     virtual void putsHeader() { puts("// Verilated -*- Verilog -*-\n"); }
 };
 
 class V3OutXmlFile : public V3OutFile {
 public:
-    V3OutXmlFile(const string& filename) : V3OutFile(filename, V3OutFormatter::LA_XML) {}
+    explicit V3OutXmlFile(const string& filename) : V3OutFile(filename, V3OutFormatter::LA_XML) {}
     virtual ~V3OutXmlFile() {}
     virtual void putsHeader() { puts("<?xml version=\"1.0\" ?>\n"); }
 };
 
 class V3OutMkFile : public V3OutFile {
 public:
-    V3OutMkFile(const string& filename) : V3OutFile(filename, V3OutFormatter::LA_MK) {}
+    explicit V3OutMkFile(const string& filename) : V3OutFile(filename, V3OutFormatter::LA_MK) {}
     virtual ~V3OutMkFile() {}
     virtual void putsHeader() { puts("# Verilated -*- Makefile -*-\n"); }
     // No automatic indentation yet.
diff --git a/src/V3FileLine.h b/src/V3FileLine.h
index 1c5e73697..b4ece08f1 100644
--- a/src/V3FileLine.h
+++ b/src/V3FileLine.h
@@ -102,9 +102,9 @@ public:
     FileLine (const string& filename, int lineno) {
 	m_lineno=lineno; m_filenameno = singleton().nameToNumber(filename);
 	m_warnOn=defaultFileLine().m_warnOn; }
-    FileLine (FileLine* fromp) {
+    explicit FileLine (FileLine* fromp) {
 	m_lineno=fromp->m_lineno; m_filenameno = fromp->m_filenameno; m_warnOn=fromp->m_warnOn; }
-    FileLine (EmptySecret);
+    explicit FileLine (EmptySecret);
     ~FileLine() { }
     FileLine* create(const string& filename, int lineno) { return new FileLine(filename,lineno); }
     FileLine* create(int lineno) { return create(filename(), lineno); }
diff --git a/src/V3Gate.cpp b/src/V3Gate.cpp
index 7ccdb3770..0f0e5ec30 100644
--- a/src/V3Gate.cpp
+++ b/src/V3Gate.cpp
@@ -496,7 +496,7 @@ private:
 
 public:
     // CONSTUCTORS
-    GateVisitor(AstNode* nodep) {
+    explicit GateVisitor(AstNode* nodep) {
 	AstNode::user1ClearTree();
 	m_logicVertexp = NULL;
 	m_scopep = NULL;
@@ -1202,7 +1202,7 @@ private:
     }
 
 public:
-    GateMergeAssignsGraphVisitor(V3Graph* graphp) {
+    explicit GateMergeAssignsGraphVisitor(V3Graph* graphp) {
 	m_assignp = NULL;
 	m_activep = NULL;
 	m_logicvp = NULL;
@@ -1253,7 +1253,7 @@ private:
 
 public:
     // CONSTUCTORS
-    GateDeassignVisitor(AstNode* nodep) {
+    explicit GateDeassignVisitor(AstNode* nodep) {
 	nodep->accept(*this);
     }
     virtual ~GateDeassignVisitor() {}
diff --git a/src/V3GenClk.cpp b/src/V3GenClk.cpp
index 736bb6f9f..cbee8f4c6 100644
--- a/src/V3GenClk.cpp
+++ b/src/V3GenClk.cpp
@@ -213,7 +213,7 @@ private:
     }
 public:
     // CONSTRUCTORS
-    GenClkReadVisitor(AstNetlist* nodep) {
+    explicit GenClkReadVisitor(AstNetlist* nodep) {
 	m_activep = NULL;
 	m_assignp = NULL;
 	m_topModp = NULL;
diff --git a/src/V3Global.h b/src/V3Global.h
index 97e8f8d2b..f1376bf03 100644
--- a/src/V3Global.h
+++ b/src/V3Global.h
@@ -46,6 +46,7 @@ public:
     };
     enum en m_e;
     inline VWidthMinUsage () : m_e(LINT_WIDTH) {}
+    // cppcheck-suppress noExplicitConstructor
     inline VWidthMinUsage (en _e) : m_e(_e) {}
     explicit inline VWidthMinUsage (int _e) : m_e(static_cast<en>(_e)) {}
     operator en () const { return m_e; }
@@ -63,7 +64,6 @@ class V3Global {
     VWidthMinUsage m_widthMinUsage;	// What AstNode::widthMin() is used for
 
     int		m_debugFileNumber;	// Number to append to debug files created
-    int		m_assertWidthsMatch;	// Tree should have width()==widthMin()
     bool	m_assertDTypesResolved;	// Tree should have dtypep()'s
     bool	m_constRemoveXs;	// Const needs to strip any Xs
     bool	m_needHInlines;		// Need __Inlines file
diff --git a/src/V3Graph.h b/src/V3Graph.h
index 80f80a976..09970af4a 100644
--- a/src/V3Graph.h
+++ b/src/V3Graph.h
@@ -167,7 +167,7 @@ protected:
     // CONSTRUCTORS
     V3GraphVertex(V3Graph* graphp, const V3GraphVertex& old);
 public:
-    V3GraphVertex(V3Graph* graphp);
+    explicit V3GraphVertex(V3Graph* graphp);
     //! Clone copy constructor. Doesn't copy edges or user/userp.
     virtual V3GraphVertex* clone(V3Graph* graphp) const {
 	return new V3GraphVertex(graphp, *this); }
diff --git a/src/V3GraphAcyc.cpp b/src/V3GraphAcyc.cpp
index 504f4f09f..8f664b598 100644
--- a/src/V3GraphAcyc.cpp
+++ b/src/V3GraphAcyc.cpp
@@ -319,6 +319,7 @@ void GraphAcyc::simplifyOne (GraphAcycVertex* avertexp) {
 					    && (!outEdgep->cutable()
 						|| inEdgep->weight()<outEdgep->weight() ))
 					   ? inEdgep : outEdgep);
+	    // cppcheck-suppress leakReturnValNotUsed
 	    edgeFromEdge(templateEdgep, inVertexp, outVertexp);
 	    // Remove old edge
 	    inEdgep->unlinkDelete(); inEdgep = NULL;
@@ -353,6 +354,7 @@ void GraphAcyc::simplifyOut (GraphAcycVertex* avertexp) {
 		    return;
 		}
 		// Make a new edge connecting the two vertices directly
+		// cppcheck-suppress leakReturnValNotUsed
 		edgeFromEdge(inEdgep, inVertexp, outVertexp);
 		// Remove old edge
 		inEdgep->unlinkDelete(); inEdgep = NULL;
diff --git a/src/V3Hashed.cpp b/src/V3Hashed.cpp
index 02a6d59cd..06b0feb3b 100644
--- a/src/V3Hashed.cpp
+++ b/src/V3Hashed.cpp
@@ -96,7 +96,7 @@ private:
 
 public:
     // CONSTUCTORS
-    HashedVisitor(AstNode* nodep) {
+    explicit HashedVisitor(AstNode* nodep) {
 	nodeHashIterate(nodep);
 	//UINFO(9,"  stmthash "<<hex<<V3Hashed::nodeHash(nodep)<<"  "<<nodep<<endl);
     }
diff --git a/src/V3Inline.cpp b/src/V3Inline.cpp
index eab88e831..c17ae69f2 100644
--- a/src/V3Inline.cpp
+++ b/src/V3Inline.cpp
@@ -185,7 +185,7 @@ private:
 
 public:
     // CONSTUCTORS
-    InlineMarkVisitor(AstNode* nodep) {
+    explicit InlineMarkVisitor(AstNode* nodep) {
 	m_modp = NULL;
 	m_stmtCnt = 0;
 	nodep->accept(*this);
@@ -227,7 +227,7 @@ private:
 
 public:
     // CONSTUCTORS
-    InlineCollectVisitor(AstNodeModule* nodep) {  // passed OLD module, not new one
+    explicit InlineCollectVisitor(AstNodeModule* nodep) {  // passed OLD module, not new one
 	nodep->accept(*this);
     }
     virtual ~InlineCollectVisitor() {}
@@ -537,7 +537,7 @@ private:
 
 public:
     // CONSTUCTORS
-    InlineVisitor(AstNode* nodep) {
+    explicit InlineVisitor(AstNode* nodep) {
 	m_modp = NULL;
 	nodep->accept(*this);
     }
diff --git a/src/V3Inst.cpp b/src/V3Inst.cpp
index 8a9007775..52d3069dc 100644
--- a/src/V3Inst.cpp
+++ b/src/V3Inst.cpp
@@ -139,7 +139,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    InstVisitor(AstNode* nodep) {
+    explicit InstVisitor(AstNode* nodep) {
 	m_modp=NULL;
 	m_cellp=NULL;
 	//
@@ -229,7 +229,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    InstDeVisitor(AstNode* nodep) {
+    explicit InstDeVisitor(AstNode* nodep) {
 	m_cellRangep=NULL;
 	m_instNum=0;
 	m_instLsb=0;
diff --git a/src/V3LangCode.h b/src/V3LangCode.h
index a9209cf90..60e746dcc 100644
--- a/src/V3LangCode.h
+++ b/src/V3LangCode.h
@@ -64,8 +64,9 @@ public:
     //
     enum en m_e;
     inline V3LangCode () : m_e(L_ERROR) {}
+    // cppcheck-suppress noExplicitConstructor
     inline V3LangCode (en _e) : m_e(_e) {}
-    V3LangCode (const char* textp);
+    explicit V3LangCode (const char* textp);
     explicit inline V3LangCode (int _e) : m_e(static_cast<en>(_e)) {}
     operator en () const { return m_e; }
 };
diff --git a/src/V3Life.cpp b/src/V3Life.cpp
index 69f2a653f..9f583ed3e 100644
--- a/src/V3Life.cpp
+++ b/src/V3Life.cpp
@@ -93,10 +93,10 @@ public:
     LifeVarEntry(SIMPLEASSIGN, AstNodeAssign* assp) {
 	init(true); simpleAssign(assp);
     }
-    LifeVarEntry(COMPLEXASSIGN) {
+    explicit LifeVarEntry(COMPLEXASSIGN) {
 	init(false); complexAssign();
     }
-    LifeVarEntry(CONSUMED) {
+    explicit LifeVarEntry(CONSUMED) {
 	init(false); consumed();
     }
     ~LifeVarEntry() {}
@@ -455,14 +455,14 @@ public:
 	m_sideEffect = false;
 	m_noopt = false;
 	{
-	    // Cpp check bug, it is deleted
-	    // cppcheck-suppress leak
 	    m_lifep = new LifeBlock (NULL, m_statep);
 	    nodep->accept(*this);
-	    delete m_lifep; m_lifep=NULL;
+	    if (m_lifep) { delete m_lifep; m_lifep=NULL; }
 	}
     }
-    virtual ~LifeVisitor() {}
+    virtual ~LifeVisitor() {
+	if (m_lifep) { delete m_lifep; m_lifep=NULL; }
+    }
 };
 
 //######################################################################
diff --git a/src/V3LifePost.cpp b/src/V3LifePost.cpp
index cce02402d..6ba6cb353 100644
--- a/src/V3LifePost.cpp
+++ b/src/V3LifePost.cpp
@@ -86,7 +86,7 @@ private:
     }
 public:
     // CONSTRUCTORS
-    LifePostElimVisitor(AstTopScope* nodep) {
+    explicit LifePostElimVisitor(AstTopScope* nodep) {
 	nodep->accept(*this);
     }
     virtual ~LifePostElimVisitor() {}
@@ -178,7 +178,7 @@ private:
     }
 public:
     // CONSTRUCTORS
-    LifePostDlyVisitor(AstNetlist* nodep) {
+    explicit LifePostDlyVisitor(AstNetlist* nodep) {
 	nodep->accept(*this);
     }
     virtual ~LifePostDlyVisitor() {
diff --git a/src/V3LinkCells.cpp b/src/V3LinkCells.cpp
index 4a75efb2a..ada7f12a2 100644
--- a/src/V3LinkCells.cpp
+++ b/src/V3LinkCells.cpp
@@ -66,7 +66,7 @@ public:
 
 class LibraryVertex : public V3GraphVertex {
 public:
-    LibraryVertex(V3Graph* graphp)
+    explicit LibraryVertex(V3Graph* graphp)
 	: V3GraphVertex(graphp) {}
     virtual ~LibraryVertex() {}
     virtual string name() const { return "*LIBRARY*"; }
diff --git a/src/V3LinkJump.cpp b/src/V3LinkJump.cpp
index 4aeb3d3ee..a19cb6c6d 100644
--- a/src/V3LinkJump.cpp
+++ b/src/V3LinkJump.cpp
@@ -246,7 +246,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    LinkJumpVisitor(AstNetlist* nodep) {
+    explicit LinkJumpVisitor(AstNetlist* nodep) {
 	m_modp = NULL;
 	m_ftaskp = NULL;
 	m_loopp = NULL;
diff --git a/src/V3LinkParse.cpp b/src/V3LinkParse.cpp
index 76ea8c6a8..e21fb5370 100644
--- a/src/V3LinkParse.cpp
+++ b/src/V3LinkParse.cpp
@@ -349,7 +349,7 @@ private:
 
 public:
     // CONSTUCTORS
-    LinkParseVisitor(AstNetlist* rootp) {
+    explicit LinkParseVisitor(AstNetlist* rootp) {
 	m_varp = NULL;
 	m_modp = NULL;
 	m_ftaskp = NULL;
diff --git a/src/V3LinkResolve.cpp b/src/V3LinkResolve.cpp
index 90ae80ce7..53a42e841 100644
--- a/src/V3LinkResolve.cpp
+++ b/src/V3LinkResolve.cpp
@@ -399,7 +399,7 @@ private:
 
 public:
     // CONSTUCTORS
-    LinkResolveVisitor(AstNetlist* rootp) {
+    explicit LinkResolveVisitor(AstNetlist* rootp) {
 	m_ftaskp = NULL;
 	m_modp = NULL;
 	m_assertp = NULL;
@@ -451,7 +451,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    LinkBotupVisitor(AstNetlist* rootp) {
+    explicit LinkBotupVisitor(AstNetlist* rootp) {
 	m_modp = NULL;
 	//
 	rootp->accept(*this);
diff --git a/src/V3Localize.cpp b/src/V3Localize.cpp
index 75c569b8f..cfa81f8a0 100644
--- a/src/V3Localize.cpp
+++ b/src/V3Localize.cpp
@@ -93,7 +93,7 @@ private:
     }
 public:
     // CONSTRUCTORS
-    LocalizeDehierVisitor(AstNetlist* nodep) {
+    explicit LocalizeDehierVisitor(AstNetlist* nodep) {
 	nodep->accept(*this);
     }
     virtual ~LocalizeDehierVisitor() {}
@@ -233,7 +233,7 @@ private:
     }
 public:
     // CONSTRUCTORS
-    LocalizeVisitor(AstNetlist* nodep) {
+    explicit LocalizeVisitor(AstNetlist* nodep) {
 	m_cfuncp = NULL;
 	nodep->accept(*this);
     }
diff --git a/src/V3Name.cpp b/src/V3Name.cpp
index 3bd52c632..9dea48823 100644
--- a/src/V3Name.cpp
+++ b/src/V3Name.cpp
@@ -137,7 +137,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    NameVisitor(AstNetlist* nodep) {
+    explicit NameVisitor(AstNetlist* nodep) {
 	nodep->accept(*this);
     }
     virtual ~NameVisitor() {}
diff --git a/src/V3Number.h b/src/V3Number.h
index 98050967e..bacf082d2 100644
--- a/src/V3Number.h
+++ b/src/V3Number.h
@@ -129,7 +129,7 @@ private:
 
 public:
     // CONSTRUCTORS
-    V3Number(FileLine* fileline) { init(fileline, 1); }
+    explicit V3Number(FileLine* fileline) { init(fileline, 1); }
     V3Number(FileLine* fileline, int width) { init(fileline, width); }  // 0=unsized
     V3Number(FileLine* fileline, int width, uint32_t value) { init(fileline, width); m_value[0]=value; opCleanThis(); }
     V3Number(FileLine* fileline, const char* source);	// Create from a verilog 32'hxxxx number.
diff --git a/src/V3Options.cpp b/src/V3Options.cpp
index a30e75ec1..45c7cb60a 100644
--- a/src/V3Options.cpp
+++ b/src/V3Options.cpp
@@ -1002,6 +1002,7 @@ void V3Options::parseOptsFile(FileLine* fl, const string& filename, bool rel) {
 	getline(*ifp, line);
 	// Strip simple comments
 	string oline;
+	// cppcheck-suppress StlMissingComparison
 	for (string::const_iterator pos = line.begin(); pos != line.end(); ++pos) {
 	    if (inCmt) {
 		if (*pos=='*' && *(pos+1)=='/') {
diff --git a/src/V3Options.h b/src/V3Options.h
index 2534c2a3a..53749713c 100644
--- a/src/V3Options.h
+++ b/src/V3Options.h
@@ -175,6 +175,8 @@ class V3Options {
 
     static string getenvSYSTEMPERLGuts();
 
+    V3Options(const V3Options&); ///< N/A, no copy constructor
+
   public:
     // CREATORS
     V3Options();
diff --git a/src/V3Order.cpp b/src/V3Order.cpp
index e24428da3..d067a7c3b 100644
--- a/src/V3Order.cpp
+++ b/src/V3Order.cpp
@@ -363,7 +363,7 @@ private:
 
 public:
     // CONSTUCTORS
-    OrderClkMarkVisitor(AstNode* nodep) {
+    explicit OrderClkMarkVisitor(AstNode* nodep) {
 	m_hasClk    = false;
 	m_inClocked = false;
 	m_inAss     = false;
@@ -410,7 +410,7 @@ private:
 
 public:
     // CONSTUCTORS
-    OrderClkAssVisitor(AstNode* nodep) {
+    explicit OrderClkAssVisitor(AstNode* nodep) {
 	m_clkAss = false;
 	nodep->accept(*this);
     }
diff --git a/src/V3OrderGraph.h b/src/V3OrderGraph.h
index a4bc6cb41..7a733653c 100644
--- a/src/V3OrderGraph.h
+++ b/src/V3OrderGraph.h
@@ -104,6 +104,7 @@ struct OrderVEdgeType {
     }
     enum en m_e;
     inline OrderVEdgeType () : m_e(VERTEX_UNKNOWN) {}
+    // cppcheck-suppress noExplicitConstructor
     inline OrderVEdgeType (en _e) : m_e(_e) {}
     explicit inline OrderVEdgeType (int _e) : m_e(static_cast<en>(_e)) {}
     operator en () const { return m_e; }
diff --git a/src/V3Param.cpp b/src/V3Param.cpp
index d5b42f934..486541af7 100644
--- a/src/V3Param.cpp
+++ b/src/V3Param.cpp
@@ -88,7 +88,7 @@ private:
     struct ModInfo {
 	AstNodeModule*	m_modp;		// Module with specified name
 	VarCloneMap	m_cloneMap;	// Map of old-varp -> new cloned varp
-	ModInfo(AstNodeModule* modp) { m_modp=modp; }
+	explicit ModInfo(AstNodeModule* modp) { m_modp=modp; }
     };
     typedef map<string,ModInfo> ModNameMap;
     ModNameMap	m_modNameMap;	// Hash of created module flavors by name
@@ -385,7 +385,7 @@ private:
 
 public:
     // CONSTUCTORS
-    ParamVisitor(AstNetlist* nodep) {
+    explicit ParamVisitor(AstNetlist* nodep) {
 	m_longId = 0;
 	//
 	nodep->accept(*this);
diff --git a/src/V3Parse.h b/src/V3Parse.h
index 14a0a5fa6..e56ac0f48 100644
--- a/src/V3Parse.h
+++ b/src/V3Parse.h
@@ -36,6 +36,7 @@ class V3Parse {
 private:
     V3ParseImp*	m_impp;
 
+    V3Parse(const V3Parse&); ///< N/A, no copy constructor
 public:
     // CONSTRUCTORS
     // We must allow reading multiple files into one parser
diff --git a/src/V3ParseSym.h b/src/V3ParseSym.h
index adc840bef..014b9e1de 100644
--- a/src/V3ParseSym.h
+++ b/src/V3ParseSym.h
@@ -133,7 +133,7 @@ public:
     }
 public:
     // CREATORS
-    V3ParseSym(AstNetlist* rootp)
+    explicit V3ParseSym(AstNetlist* rootp)
 	: m_syms(rootp) {
 	s_anonNum = 0;		// Number of next anonymous object
 	pushScope(findNewTable(rootp));
diff --git a/src/V3Premit.cpp b/src/V3Premit.cpp
index 39163d931..8f1242530 100644
--- a/src/V3Premit.cpp
+++ b/src/V3Premit.cpp
@@ -85,7 +85,7 @@ private:
 
 public:
     // CONSTRUCTORS
-    PremitAssignVisitor(AstNodeAssign* nodep) {
+    explicit PremitAssignVisitor(AstNodeAssign* nodep) {
 	UINFO(4,"  PremitAssignVisitor on "<<nodep<<endl);
 	m_noopt = false;
 	nodep->accept(*this);
@@ -383,7 +383,7 @@ private:
 
 public:
     // CONSTUCTORS
-    PremitVisitor(AstNetlist* nodep) {
+    explicit PremitVisitor(AstNetlist* nodep) {
 	m_modp = NULL;
 	m_funcp = NULL;
 	m_stmtp = NULL;
diff --git a/src/V3Scope.cpp b/src/V3Scope.cpp
index c253d0afd..3588d3a19 100644
--- a/src/V3Scope.cpp
+++ b/src/V3Scope.cpp
@@ -294,7 +294,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    ScopeVisitor(AstNetlist* nodep) {
+    explicit ScopeVisitor(AstNetlist* nodep) {
 	m_aboveCellp = NULL;
 	m_aboveScopep = NULL;
 	m_modp = NULL;
@@ -402,7 +402,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    ScopeCleanupVisitor(AstNetlist* nodep) {
+    explicit ScopeCleanupVisitor(AstNetlist* nodep) {
 	m_scopep = NULL;
 	nodep->accept(*this);
     }
diff --git a/src/V3Simulate.h b/src/V3Simulate.h
index 8bc4decb6..ac4dc9253 100644
--- a/src/V3Simulate.h
+++ b/src/V3Simulate.h
@@ -655,6 +655,7 @@ private:
 	AstNodeFTask* funcp = nodep->taskp()->castNodeFTask(); if (!funcp) nodep->v3fatalSrc("Not linked");
 	// cppcheck-suppress redundantAssignment
 	if (m_params) { V3Width::widthParamsEdit(funcp); } funcp=NULL; // Make sure we've sized the function
+	// cppcheck-suppress redundantAssignment
 	funcp = nodep->taskp()->castNodeFTask(); if (!funcp) nodep->v3fatalSrc("Not linked");
 	// Apply function call values to function
 	V3TaskConnects tconnects = V3Task::taskConnects(nodep, nodep->taskp()->stmtsp());
diff --git a/src/V3Slice.cpp b/src/V3Slice.cpp
index 6403271cf..076cb817b 100644
--- a/src/V3Slice.cpp
+++ b/src/V3Slice.cpp
@@ -185,7 +185,7 @@ class SliceCloneVisitor : public AstNVisitor {
     }
 public:
     // CONSTUCTORS
-    SliceCloneVisitor(AstNode* nodep) {
+    explicit SliceCloneVisitor(AstNode* nodep) {
 	nodep->accept(*this);
     }
     virtual ~SliceCloneVisitor() {}
@@ -487,7 +487,7 @@ class SliceVisitor : public AstNVisitor {
 
 public:
     // CONSTUCTORS
-    SliceVisitor(AstNetlist* rootp) {
+    explicit SliceVisitor(AstNetlist* rootp) {
 	m_assignp = NULL;
 	m_lhsVarRefp = NULL;
 	rootp->accept(*this);
diff --git a/src/V3Split.cpp b/src/V3Split.cpp
index effdfbd8a..1c967edc7 100644
--- a/src/V3Split.cpp
+++ b/src/V3Split.cpp
@@ -69,7 +69,7 @@
 
 class SplitPliVertex : public V3GraphVertex {
 public:
-    SplitPliVertex(V3Graph* graphp)
+    explicit SplitPliVertex(V3Graph* graphp)
 	: V3GraphVertex(graphp) {}
     virtual ~SplitPliVertex() {}
     virtual string name() const { return "*PLI*"; }
diff --git a/src/V3SplitAs.cpp b/src/V3SplitAs.cpp
index b0cd367e9..7a3da7f70 100644
--- a/src/V3SplitAs.cpp
+++ b/src/V3SplitAs.cpp
@@ -71,7 +71,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    SplitAsFindVisitor(AstAlways* nodep) {
+    explicit SplitAsFindVisitor(AstAlways* nodep) {
 	m_splitVscp = NULL;
 	nodep->accept(*this);
     }
@@ -200,7 +200,7 @@ private:
 
 public:
     // CONSTUCTORS
-    SplitAsVisitor(AstNetlist* nodep) {
+    explicit SplitAsVisitor(AstNetlist* nodep) {
 	m_splitVscp = NULL;
 	AstNode::user1ClearTree();	// user1p() used on entire tree
 	nodep->accept(*this);
diff --git a/src/V3Stats.h b/src/V3Stats.h
index 067316293..d686927a6 100644
--- a/src/V3Stats.h
+++ b/src/V3Stats.h
@@ -37,7 +37,7 @@ public:
     ~V3Double0() {}
 
     // Implicit conversion operators:
-    inline V3Double0 (const vluint64_t v) : m_d(v) { }
+    inline explicit V3Double0 (const vluint64_t v) : m_d(v) { }
     inline operator double () const { return m_d; }
 
     // Explicit operators:
diff --git a/src/V3StatsReport.cpp b/src/V3StatsReport.cpp
index 34b7d39fc..098680176 100644
--- a/src/V3StatsReport.cpp
+++ b/src/V3StatsReport.cpp
@@ -177,7 +177,7 @@ public:
     }
 
     // CONSTRUCTORS
-    StatsReport(ofstream* aofp)
+    explicit StatsReport(ofstream* aofp)
 	: os(*aofp) {
 	header();
 	sumit();
diff --git a/src/V3String.h b/src/V3String.h
index 99c256e58..355de273d 100644
--- a/src/V3String.h
+++ b/src/V3String.h
@@ -54,7 +54,7 @@ class VHashSha1 {
 public:
     // CONSTRUCTORS
     VHashSha1() { init(); }
-    VHashSha1(const string& data) { init(); insert(data); }
+    explicit VHashSha1(const string& data) { init(); insert(data); }
     ~VHashSha1() {}
 
     // METHODS
@@ -93,7 +93,7 @@ class VName {
     static size_t s_minLength;		// Length to preserve if over maxLength
 public:
     // CONSTRUCTORS
-    VName (const string& name) : m_name(name) {}
+    explicit VName (const string& name) : m_name(name) {}
     ~VName() {}
     // METHODS
     void name(const string& name) { m_name = name; m_hashed = ""; }
diff --git a/src/V3Subst.cpp b/src/V3Subst.cpp
index 3f248d733..8aa380184 100644
--- a/src/V3Subst.cpp
+++ b/src/V3Subst.cpp
@@ -86,7 +86,7 @@ class SubstVarEntry {
 
 public:
     // CONSTRUCTORS
-    SubstVarEntry (AstVar* varp) {	// Construction for when a var is used
+    explicit SubstVarEntry (AstVar* varp) {	// Construction for when a var is used
 	m_varp = varp;
 	m_whole.m_use = false;
 	m_wordAssign = false;
@@ -379,7 +379,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    SubstVisitor(AstNode* nodep) {
+    explicit SubstVisitor(AstNode* nodep) {
 	AstNode::user1ClearTree();	// user1p() used on entire tree
 	AstNode::user2ClearTree();	// user2p() used on entire tree
 	m_ops = 0;
diff --git a/src/V3SymTable.h b/src/V3SymTable.h
index 62f6b64d3..fa7c51e28 100644
--- a/src/V3SymTable.h
+++ b/src/V3SymTable.h
@@ -226,6 +226,8 @@ private:
     VSymEnt*	m_symRootp;		// Root symbol table
     SymStack	m_symsp;		// All symbol tables, to cleanup
 
+    VSymGraph(const VSymGraph&);	///< N/A, no copy constructor
+
 protected:
     friend class VSymEnt;
     void pushNewEnt(VSymEnt* entp) { m_symsp.push_back(entp); }
@@ -256,7 +258,7 @@ public:
     }
 public:
     // CREATORS
-    VSymGraph(AstNetlist* nodep) {
+    explicit VSymGraph(AstNetlist* nodep) {
 	m_symRootp = new VSymEnt(this, nodep);
     }
     ~VSymGraph() {
diff --git a/src/V3Table.cpp b/src/V3Table.cpp
index 18e32b2bd..b2f121903 100644
--- a/src/V3Table.cpp
+++ b/src/V3Table.cpp
@@ -60,7 +60,7 @@ public:
     virtual void varRefCb(AstVarRef* nodep);	///< Call other-this function on all new var references
 
     // CONSTRUCTORS
-    TableSimulateVisitor(TableVisitor* cbthis) {
+    explicit TableSimulateVisitor(TableVisitor* cbthis) {
 	m_cbthis = cbthis;
     }
     virtual ~TableSimulateVisitor() {}
@@ -437,7 +437,7 @@ private:
     }
 public:
     // CONSTRUCTORS
-    TableVisitor(AstNetlist* nodep) {
+    explicit TableVisitor(AstNetlist* nodep) {
 	m_modp = NULL;
 	m_modTables = 0;
 	m_scopep = NULL;
diff --git a/src/V3Task.cpp b/src/V3Task.cpp
index 802457e11..494447d95 100644
--- a/src/V3Task.cpp
+++ b/src/V3Task.cpp
@@ -49,7 +49,7 @@ class TaskBaseVertex : public V3GraphVertex {
     AstNode*	m_impurep;	// Node causing impure function w/ outside references
     bool	m_noInline;	// Marked with pragma
 public:
-    TaskBaseVertex(V3Graph* graphp)
+    explicit TaskBaseVertex(V3Graph* graphp)
 	: V3GraphVertex(graphp), m_impurep(NULL), m_noInline(false) {}
     virtual ~TaskBaseVertex() {}
     bool pure() const { return m_impurep==NULL; }
@@ -79,7 +79,7 @@ public:
 class TaskCodeVertex : public TaskBaseVertex {
     // Top vertex for all calls not under another task
 public:
-    TaskCodeVertex(V3Graph* graphp)
+    explicit TaskCodeVertex(V3Graph* graphp)
 	: TaskBaseVertex(graphp) {}
     virtual ~TaskCodeVertex() {}
     virtual string name() const { return "*CODE*"; }
@@ -234,7 +234,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    TaskStateVisitor(AstNetlist* nodep) {
+    explicit TaskStateVisitor(AstNetlist* nodep) {
 	m_assignwp = NULL;
 	m_curVxp = new TaskCodeVertex(&m_callGraph);
 	AstNode::user3ClearTree();
@@ -277,7 +277,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    TaskRelinkVisitor(AstBegin* nodep) {  // Passed temporary tree
+    explicit TaskRelinkVisitor(AstBegin* nodep) {  // Passed temporary tree
 	nodep->accept(*this);
     }
     virtual ~TaskRelinkVisitor() {}
diff --git a/src/V3Trace.cpp b/src/V3Trace.cpp
index f35111006..52c366783 100644
--- a/src/V3Trace.cpp
+++ b/src/V3Trace.cpp
@@ -677,7 +677,7 @@ private:
 
 public:
     // CONSTUCTORS
-    TraceVisitor(AstNetlist* nodep) {
+    explicit TraceVisitor(AstNetlist* nodep) {
 	m_funcp = NULL;
 	m_tracep = NULL;
 	m_topModp = NULL;
diff --git a/src/V3TraceDecl.cpp b/src/V3TraceDecl.cpp
index 91bbf7148..00398afb9 100644
--- a/src/V3TraceDecl.cpp
+++ b/src/V3TraceDecl.cpp
@@ -108,9 +108,6 @@ private:
 	basep->addStmtsp(callp);
 	return funcp;
     }
-    void addCFuncStmt(AstCFunc* basep, AstNode* nodep, VNumRange arrayRange) {
-	basep->addStmtsp(nodep);
-    }
     void addTraceDecl(const VNumRange& arrayRange,
 		      int widthOverride) {  // If !=0, is packed struct/array where basicp size misreflects one element
 	VNumRange bitRange;
@@ -305,7 +302,7 @@ private:
 
 public:
     // CONSTUCTORS
-    TraceDeclVisitor(AstNetlist* nodep) {
+    explicit TraceDeclVisitor(AstNetlist* nodep) {
 	m_scopetopp = NULL;
 	m_initFuncp = NULL;
 	m_initSubFuncp = NULL;
diff --git a/src/V3Tristate.cpp b/src/V3Tristate.cpp
index 7f787a9da..18280dd84 100644
--- a/src/V3Tristate.cpp
+++ b/src/V3Tristate.cpp
@@ -1302,7 +1302,7 @@ class TristateVisitor : public TristateBaseVisitor {
 
 public:
     // CONSTUCTORS
-    TristateVisitor(AstNode* nodep) {
+    explicit TristateVisitor(AstNode* nodep) {
 	m_graphing = false;
 	m_modp  = NULL;
 	m_cellp = NULL;
diff --git a/src/V3Undriven.cpp b/src/V3Undriven.cpp
index 8fd105119..9ca63c752 100644
--- a/src/V3Undriven.cpp
+++ b/src/V3Undriven.cpp
@@ -60,7 +60,7 @@ class UndrivenVarEntry {
 
 public:
     // CONSTRUCTORS
-    UndrivenVarEntry (AstVar* varp) {	// Construction for when a var is used
+    explicit UndrivenVarEntry (AstVar* varp) {	// Construction for when a var is used
 	UINFO(9, "create "<<varp<<endl);
 	m_varp = varp;
 	m_usedWhole = false;
@@ -370,7 +370,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    UndrivenVisitor(AstNetlist* nodep) {
+    explicit UndrivenVisitor(AstNetlist* nodep) {
 	m_markBoth = false;
 	m_taskp = NULL;
 	m_alwaysp = NULL;
diff --git a/src/V3Unknown.cpp b/src/V3Unknown.cpp
index 5b51dadb2..df10f565b 100644
--- a/src/V3Unknown.cpp
+++ b/src/V3Unknown.cpp
@@ -457,7 +457,7 @@ private:
 
 public:
     // CONSTUCTORS
-    UnknownVisitor(AstNetlist* nodep) {
+    explicit UnknownVisitor(AstNetlist* nodep) {
 	m_modp = NULL;
 	m_assigndlyp = NULL;
 	m_assignwp = NULL;
diff --git a/src/V3Width.cpp b/src/V3Width.cpp
index 8a6757740..344281533 100644
--- a/src/V3Width.cpp
+++ b/src/V3Width.cpp
@@ -452,7 +452,7 @@ private:
 	    if (!constp) { nodep->v3error("Replication value isn't a constant."); return; }
 	    uint32_t times = constp->toUInt();
 	    if (times==0 && !nodep->backp()->castConcat()) {  // Concat Visitor will clean it up.
-		nodep->v3error("Replication value of 0 is only legal under a concatenation."); times=1;
+		nodep->v3error("Replication value of 0 is only legal under a concatenation.");
 	    }
 	    nodep->dtypeSetString();
 	}
diff --git a/src/V3WidthCommit.h b/src/V3WidthCommit.h
index ed71a5482..1b49c1b3c 100644
--- a/src/V3WidthCommit.h
+++ b/src/V3WidthCommit.h
@@ -151,7 +151,7 @@ private:
     }
 public:
     // CONSTUCTORS
-    WidthCommitVisitor(AstNetlist* nodep) {
+    explicit WidthCommitVisitor(AstNetlist* nodep) {
 	// Were changing widthMin's, so the table is now somewhat trashed
 	nodep->typeTablep()->clearCache();
 	nodep->accept(*this);
diff --git a/src/VlcSource.h b/src/VlcSource.h
index 6ff542945..771fcea6a 100644
--- a/src/VlcSource.h
+++ b/src/VlcSource.h
@@ -77,7 +77,7 @@ private:
 
 public:
     // CONSTRUCTORS
-    VlcSource(const string& name) {
+    explicit VlcSource(const string& name) {
 	m_name = name;
 	m_needed = false;
     }
diff --git a/src/cppcheck_filtered b/src/cppcheck_filtered
index 6e1c6e2bd..69a45e689 100755
--- a/src/cppcheck_filtered
+++ b/src/cppcheck_filtered
@@ -64,6 +64,7 @@ sub process {
 	next if $line =~ m!id="missingInclude" .*systemc.h!;
 	next if $line =~ m!id="missingInclude" .*svdpi.h!;
 	next if $line =~ m!id="unusedFunction" .*sv! && $line =~ m!verilated_dpi.cpp!;
+	next if $line =~ m!id="unusedFunction" .*vpi! && $line =~ m!verilated_vpi.cpp!;
 	next if $line =~ m!id="unusedPrivateFunction" .*::debug!;  # Doesn't know UINFO will use it
 	next if $line =~ m!file=".*obj_dbg/V3ParseBison.c".* id="unreachableCode"!;
 	# Output
@@ -124,6 +125,12 @@ sub _suppress {
 		# delete(nodep); nodep=NULL;   # This is ok, it's how we prevent later using nodep
 		return 1;
 	    }
+	    if (($id eq "uselessAssignment"
+		 || $id eq "uselessAssignmentPtrArg")
+		&& $line =~ /;.*p *= *NULL;/) {
+		# delete(nodep); nodep=NULL;   # This is ok, it's how we prevent later using nodep
+		return 1;
+	    }
 	}
     }
     return undef;
diff --git a/src/verilog.l b/src/verilog.l
index a188f3858..8163af4d0 100644
--- a/src/verilog.l
+++ b/src/verilog.l
@@ -986,7 +986,7 @@ double V3ParseImp::parseDouble(const char* textp, size_t length) {
     double d = strtod(strgp, &endp);
     size_t parsed_len = endp-strgp;
     if (parsed_len != strlen(strgp)) { yyerrorf("Syntax error parsing real: %s",strgp); }
-    delete strgp;
+    delete[] strgp;
     return d;
 }