From 9f3750d0ccb9450b4612ce2c98aa2a298e4d0dd6 Mon Sep 17 00:00:00 2001
From: Tim Wojtulewicz <tim@corelight.com>
Date: Fri, 27 Jan 2023 08:03:08 -0700
Subject: [PATCH] binpac: Apply clang-tidy's modernize-use-nullptr check

---
 tools/binpac/lib/binpac_buffer.cc | 10 ++---
 tools/binpac/lib/binpac_regex.cc  |  2 +-
 tools/binpac/src/pac_action.cc    |  2 +-
 tools/binpac/src/pac_analyzer.cc  | 10 ++---
 tools/binpac/src/pac_array.cc     | 34 +++++++-------
 tools/binpac/src/pac_array.h      |  2 +-
 tools/binpac/src/pac_attr.cc      |  4 +-
 tools/binpac/src/pac_btype.cc     |  4 +-
 tools/binpac/src/pac_case.cc      | 14 +++---
 tools/binpac/src/pac_case.h       |  2 +-
 tools/binpac/src/pac_conn.cc      |  6 +--
 tools/binpac/src/pac_context.cc   |  6 +--
 tools/binpac/src/pac_decl.cc      |  8 ++--
 tools/binpac/src/pac_decl.h       |  2 +-
 tools/binpac/src/pac_embedded.cc  |  2 +-
 tools/binpac/src/pac_enum.cc      |  2 +-
 tools/binpac/src/pac_expr.cc      | 40 ++++++++---------
 tools/binpac/src/pac_field.cc     |  2 +-
 tools/binpac/src/pac_flow.cc      | 14 +++---
 tools/binpac/src/pac_func.cc      |  6 +--
 tools/binpac/src/pac_id.cc        | 75 ++++++++++++++++---------------
 tools/binpac/src/pac_main.cc      |  8 ++--
 tools/binpac/src/pac_paramtype.cc |  2 +-
 tools/binpac/src/pac_primitive.cc |  6 +--
 tools/binpac/src/pac_record.cc    | 28 ++++++------
 tools/binpac/src/pac_record.h     |  2 +-
 tools/binpac/src/pac_strtype.cc   | 13 +++---
 tools/binpac/src/pac_type.cc      | 44 +++++++++---------
 tools/binpac/src/pac_typedecl.cc  | 14 +++---
 29 files changed, 183 insertions(+), 181 deletions(-)

diff --git a/tools/binpac/lib/binpac_buffer.cc b/tools/binpac/lib/binpac_buffer.cc
index 9469251413..56ad6a8b77 100644
--- a/tools/binpac/lib/binpac_buffer.cc
+++ b/tools/binpac/lib/binpac_buffer.cc
@@ -30,10 +30,10 @@ binpac::FlowBuffer::Policy binpac::FlowBuffer::policy = {
 FlowBuffer::FlowBuffer(LineBreakStyle linebreak_style)
 	{
 	buffer_length_ = 0;
-	buffer_ = 0;
+	buffer_ = nullptr;
 
-	orig_data_begin_ = 0;
-	orig_data_end_ = 0;
+	orig_data_begin_ = nullptr;
+	orig_data_end_ = nullptr;
 
 	linebreak_style_ = linebreak_style;
 	linebreak_style_default = linebreak_style;
@@ -209,7 +209,7 @@ void FlowBuffer::DiscardData()
 	mode_ = UNKNOWN_MODE;
 	message_complete_ = false;
 	have_pending_request_ = false;
-	orig_data_begin_ = orig_data_end_ = 0;
+	orig_data_begin_ = orig_data_end_ = nullptr;
 
 	buffer_n_ = 0;
 	frame_length_ = 0;
@@ -289,7 +289,7 @@ void FlowBuffer::NewGap(int length)
 			frame_length_ = 0;
 		}
 
-	orig_data_begin_ = orig_data_end_ = 0;
+	orig_data_begin_ = orig_data_end_ = nullptr;
 	MarkOrCopy();
 	}
 
diff --git a/tools/binpac/lib/binpac_regex.cc b/tools/binpac/lib/binpac_regex.cc
index 22edffddcc..38379623de 100644
--- a/tools/binpac/lib/binpac_regex.cc
+++ b/tools/binpac/lib/binpac_regex.cc
@@ -6,6 +6,6 @@ namespace zeek { class RE_Matcher; }
 namespace binpac
 	{
 
-std::vector<zeek::RE_Matcher*>* uncompiled_re_matchers = 0;
+std::vector<zeek::RE_Matcher*>* uncompiled_re_matchers = nullptr;
 
 	}
diff --git a/tools/binpac/src/pac_action.cc b/tools/binpac/src/pac_action.cc
index 549672ad88..6a536184ee 100644
--- a/tools/binpac/src/pac_action.cc
+++ b/tools/binpac/src/pac_action.cc
@@ -10,7 +10,7 @@
 
 AnalyzerAction::AnalyzerAction(ID* action_id, When when, ActionParam* param, EmbeddedCode* code)
 	: AnalyzerElement(ACTION), action_id_(action_id), when_(when), param_(param), code_(code),
-	  analyzer_(0)
+	  analyzer_(nullptr)
 	{
 	}
 
diff --git a/tools/binpac/src/pac_analyzer.cc b/tools/binpac/src/pac_analyzer.cc
index 918678cadb..3a3b5a7c7b 100644
--- a/tools/binpac/src/pac_analyzer.cc
+++ b/tools/binpac/src/pac_analyzer.cc
@@ -30,7 +30,7 @@ AnalyzerDecl::AnalyzerDecl(ID* id, DeclType decl_type, ParamList* params)
 
 	SetAnalyzerContext();
 
-	env_ = 0;
+	env_ = nullptr;
 	}
 
 AnalyzerDecl::~AnalyzerDecl()
@@ -205,7 +205,7 @@ void AnalyzerDecl::GenInitCode(Output* out_cc)
 	TypeDecl::GenInitCode(out_cc);
 	foreach (i, AnalyzerHelperList, constructor_helpers_)
 		{
-		(*i)->GenCode(0, out_cc, this);
+		(*i)->GenCode(nullptr, out_cc, this);
 		}
 	}
 
@@ -214,7 +214,7 @@ void AnalyzerDecl::GenCleanUpCode(Output* out_cc)
 	TypeDecl::GenCleanUpCode(out_cc);
 	foreach (i, AnalyzerHelperList, destructor_helpers_)
 		{
-		(*i)->GenCode(0, out_cc, this);
+		(*i)->GenCode(nullptr, out_cc, this);
 		}
 	}
 
@@ -277,7 +277,7 @@ AnalyzerHelper::~AnalyzerHelper()
 
 void AnalyzerHelper::GenCode(Output* out_h, Output* out_cc, AnalyzerDecl* decl)
 	{
-	Output* out = 0;
+	Output* out = nullptr;
 	switch ( helper_type_ )
 		{
 		case MEMBER_DECLS:
@@ -318,7 +318,7 @@ AnalyzerFlow::AnalyzerFlow(Direction dir, ID* type_id, ExprList* params)
 
 	flow_field_ = new FlowField(flow_id, flow_type);
 
-	flow_decl_ = 0;
+	flow_decl_ = nullptr;
 	}
 
 AnalyzerFlow::~AnalyzerFlow()
diff --git a/tools/binpac/src/pac_array.cc b/tools/binpac/src/pac_array.cc
index ebaed479ca..d37a6c1a4d 100644
--- a/tools/binpac/src/pac_array.cc
+++ b/tools/binpac/src/pac_array.cc
@@ -37,13 +37,13 @@ ArrayType::ArrayType(Type* elemtype, Expr* length)
 
 void ArrayType::init()
 	{
-	arraylength_var_field_ = 0;
-	elem_it_var_field_ = 0;
-	elem_var_field_ = 0;
-	elem_dataptr_var_field_ = 0;
-	elem_input_var_field_ = 0;
+	arraylength_var_field_ = nullptr;
+	elem_it_var_field_ = nullptr;
+	elem_var_field_ = nullptr;
+	elem_dataptr_var_field_ = nullptr;
+	elem_input_var_field_ = nullptr;
 
-	elem_dataptr_until_expr_ = 0;
+	elem_dataptr_until_expr_ = nullptr;
 
 	end_of_array_loop_label_ = "@@@";
 
@@ -51,9 +51,9 @@ void ArrayType::init()
 
 	datatype_str_ = strfmt("%s *", vector_str_.c_str());
 
-	attr_generic_until_expr_ = 0;
-	attr_until_element_expr_ = 0;
-	attr_until_input_expr_ = 0;
+	attr_generic_until_expr_ = nullptr;
+	attr_until_element_expr_ = nullptr;
+	attr_until_input_expr_ = nullptr;
 	}
 
 ArrayType::~ArrayType()
@@ -71,7 +71,7 @@ Type* ArrayType::DoClone() const
 	{
 	Type* elemtype = elemtype_->Clone();
 	if ( ! elemtype )
-		return 0;
+		return nullptr;
 	return new ArrayType(elemtype, length_);
 	}
 
@@ -100,27 +100,27 @@ string ArrayType::EvalElement(const string& array, const string& index) const
 
 const ID* ArrayType::arraylength_var() const
 	{
-	return arraylength_var_field_ ? arraylength_var_field_->id() : 0;
+	return arraylength_var_field_ ? arraylength_var_field_->id() : nullptr;
 	}
 
 const ID* ArrayType::elem_it_var() const
 	{
-	return elem_it_var_field_ ? elem_it_var_field_->id() : 0;
+	return elem_it_var_field_ ? elem_it_var_field_->id() : nullptr;
 	}
 
 const ID* ArrayType::elem_var() const
 	{
-	return elem_var_field_ ? elem_var_field_->id() : 0;
+	return elem_var_field_ ? elem_var_field_->id() : nullptr;
 	}
 
 const ID* ArrayType::elem_dataptr_var() const
 	{
-	return elem_dataptr_var_field_ ? elem_dataptr_var_field_->id() : 0;
+	return elem_dataptr_var_field_ ? elem_dataptr_var_field_->id() : nullptr;
 	}
 
 const ID* ArrayType::elem_input_var() const
 	{
-	return elem_input_var_field_ ? elem_input_var_field_->id() : 0;
+	return elem_input_var_field_ ? elem_input_var_field_->id() : nullptr;
 	}
 
 void ArrayType::ProcessAttr(Attr* a)
@@ -499,7 +499,7 @@ void ArrayType::DoGenParseCode(Output* out_cc, Env* env, const DataPtr& data, in
 
 	ASSERT(elem_it_var());
 
-	DataPtr elem_data(env, 0, 0);
+	DataPtr elem_data(env, nullptr, 0);
 
 	if ( elem_dataptr_var() )
 		{
@@ -554,7 +554,7 @@ void ArrayType::DoGenParseCode(Output* out_cc, Env* env, const DataPtr& data, in
 	if ( elem_dataptr_var() )
 		{
 		out_cc->println("%s += %s;", env->LValue(elem_dataptr_var()),
-		                elemtype_->DataSize(0, env, elem_data).c_str());
+		                elemtype_->DataSize(nullptr, env, elem_data).c_str());
 		out_cc->println("BINPAC_ASSERT(%s <= %s);", env->RValue(elem_dataptr_var()),
 		                env->RValue(end_of_data));
 		}
diff --git a/tools/binpac/src/pac_array.h b/tools/binpac/src/pac_array.h
index 2433803fab..01f770d1d5 100644
--- a/tools/binpac/src/pac_array.h
+++ b/tools/binpac/src/pac_array.h
@@ -9,7 +9,7 @@
 class ArrayType : public Type
 	{
 public:
-	ArrayType(Type* arg_elemtype, Expr* arg_length = 0);
+	ArrayType(Type* arg_elemtype, Expr* arg_length = nullptr);
 	~ArrayType();
 
 	bool DefineValueVar() const;
diff --git a/tools/binpac/src/pac_attr.cc b/tools/binpac/src/pac_attr.cc
index 004388eb87..b4ba16e37c 100644
--- a/tools/binpac/src/pac_attr.cc
+++ b/tools/binpac/src/pac_attr.cc
@@ -16,8 +16,8 @@ bool Attr::RequiresAnalyzerContext() const
 
 void Attr::init()
 	{
-	expr_ = 0;
-	seqend_ = 0;
+	expr_ = nullptr;
+	seqend_ = nullptr;
 	delete_expr_ = false;
 	}
 
diff --git a/tools/binpac/src/pac_btype.cc b/tools/binpac/src/pac_btype.cc
index ae09bdb42b..47939dde8c 100644
--- a/tools/binpac/src/pac_btype.cc
+++ b/tools/binpac/src/pac_btype.cc
@@ -25,7 +25,7 @@ static const char* basic_pactype_name[] = {
 #define TYPE_DEF(name, pactype, ctype, size) pactype,
 #include "pac_type.def"
 #undef TYPE_DEF
-	0,
+	nullptr,
 };
 
 void BuiltInType::static_init()
@@ -49,7 +49,7 @@ static const char* basic_ctype_name[] = {
 #define TYPE_DEF(name, pactype, ctype, size) ctype,
 #include "pac_type.def"
 #undef TYPE_DEF
-	0,
+	nullptr,
 };
 
 bool BuiltInType::DefineValueVar() const
diff --git a/tools/binpac/src/pac_case.cc b/tools/binpac/src/pac_case.cc
index 2d326bf597..68fede97ad 100644
--- a/tools/binpac/src/pac_case.cc
+++ b/tools/binpac/src/pac_case.cc
@@ -15,7 +15,7 @@
 CaseType::CaseType(Expr* index_expr, CaseFieldList* cases)
 	: Type(CASE), index_expr_(index_expr), cases_(cases) 
 	{
-	index_var_ = 0;
+	index_var_ = nullptr;
 	foreach (i, CaseFieldList, cases_)
 		AddField(*i);
 	}
@@ -55,7 +55,7 @@ Type* CaseType::ValueType() const
 		return c->type();
 		}
 	ASSERT(0);
-	return 0;
+	return nullptr;
 	}
 
 string CaseType::DefaultValue() const
@@ -70,11 +70,11 @@ void CaseType::Prepare(Env* env, int flags)
 	index_var_ = new ID(strfmt("%s_case_index", value_var()->Name()));
 	// Unable to get the type for index_var_ at this moment, but we'll
 	// generate the right type based on index_expr_ later.
-	env->AddID(index_var_, MEMBER_VAR, 0);
+	env->AddID(index_var_, MEMBER_VAR, nullptr);
 
 	// Sort the cases_ to put the default case at the end of the list
 	CaseFieldList::iterator default_case_it = cases_->end(); // to avoid warning
-	CaseField* default_case = 0;
+	CaseField* default_case = nullptr;
 
 	foreach (i, CaseFieldList, cases_)
 		{
@@ -173,7 +173,7 @@ void CaseType::DoGenParseCode(Output* out_cc, Env* env, const DataPtr& data, int
 	foreach (i, CaseFieldList, cases_)
 		{
 		CaseField* c = *i;
-		c->GenParseCode(out_cc, env, data, compute_size_var ? size_var() : 0);
+		c->GenParseCode(out_cc, env, data, compute_size_var ? size_var() : nullptr);
 		if ( c->IsDefaultCase() )
 			has_default_case = true;
 		}
@@ -249,8 +249,8 @@ CaseField::CaseField(ExprList* index, ID* id, Type* type)
 	{
 	ASSERT(type_);
 	type_->set_value_var(id, MEMBER_VAR);
-	case_type_ = 0;
-	index_var_ = 0;
+	case_type_ = nullptr;
+	index_var_ = nullptr;
 	}
 
 CaseField::~CaseField()
diff --git a/tools/binpac/src/pac_case.h b/tools/binpac/src/pac_case.h
index 560dd8e35f..7d440fffa0 100644
--- a/tools/binpac/src/pac_case.h
+++ b/tools/binpac/src/pac_case.h
@@ -39,7 +39,7 @@ public:
 protected:
 	void DoGenParseCode(Output* out, Env* env, const DataPtr& data, int flags);
 	void GenDynamicSize(Output* out, Env* env, const DataPtr& data);
-	Type* DoClone() const { return 0; }
+	Type* DoClone() const { return nullptr; }
 	void DoMarkIncrementalInput();
 
 	bool ByteOrderSensitive() const;
diff --git a/tools/binpac/src/pac_conn.cc b/tools/binpac/src/pac_conn.cc
index 409ae1e43a..385be6245e 100644
--- a/tools/binpac/src/pac_conn.cc
+++ b/tools/binpac/src/pac_conn.cc
@@ -13,9 +13,9 @@
 ConnDecl::ConnDecl(ID* conn_id, ParamList* params, AnalyzerElementList* elemlist)
 	: AnalyzerDecl(conn_id, CONN, params)
 	{
-	flows_[0] = flows_[1] = 0;
+	flows_[0] = flows_[1] = nullptr;
 	AddElements(elemlist);
-	data_type_ = new ParameterizedType(conn_id->clone(), 0);
+	data_type_ = new ParameterizedType(conn_id->clone(), nullptr);
 	}
 
 ConnDecl::~ConnDecl()
@@ -92,7 +92,7 @@ void ConnDecl::GenEOFFunc(Output* out_h, Output* out_cc)
 
 	foreach (i, AnalyzerHelperList, eof_helpers_)
 		{
-		(*i)->GenCode(0, out_cc, this);
+		(*i)->GenCode(nullptr, out_cc, this);
 		}
 
 	out_cc->dec_indent();
diff --git a/tools/binpac/src/pac_context.cc b/tools/binpac/src/pac_context.cc
index 6d7c12b6df..773014eeb7 100644
--- a/tools/binpac/src/pac_context.cc
+++ b/tools/binpac/src/pac_context.cc
@@ -16,7 +16,7 @@ ContextField::ContextField(ID* id, Type* type)
 	{
 	}
 
-AnalyzerContextDecl* AnalyzerContextDecl::current_analyzer_context_ = 0;
+AnalyzerContextDecl* AnalyzerContextDecl::current_analyzer_context_ = nullptr;
 
 namespace
 	{
@@ -38,7 +38,7 @@ AnalyzerContextDecl::AnalyzerContextDecl(ID* id, ContextFieldList* context_field
                new DummyType())
 	{
 	context_name_id_ = id;
-	if ( current_analyzer_context_ != 0 )
+	if ( current_analyzer_context_ != nullptr )
 		{
 		throw Exception(this, strfmt("multiple declaration of analyzer context; "
 		                             "the previous one is `%s'",
@@ -49,7 +49,7 @@ AnalyzerContextDecl::AnalyzerContextDecl(ID* id, ContextFieldList* context_field
 
 	context_fields_ = context_fields;
 
-	param_type_ = new ParameterizedType(id_->clone(), 0);
+	param_type_ = new ParameterizedType(id_->clone(), nullptr);
 
 	flow_buffer_added_ = false;
 
diff --git a/tools/binpac/src/pac_decl.cc b/tools/binpac/src/pac_decl.cc
index 3982e10116..fc0f74ea64 100644
--- a/tools/binpac/src/pac_decl.cc
+++ b/tools/binpac/src/pac_decl.cc
@@ -14,10 +14,10 @@
 #include "pac_type.h"
 #include "pac_utils.h"
 
-DeclList* Decl::decl_list_ = 0;
+DeclList* Decl::decl_list_ = nullptr;
 Decl::DeclMap Decl::decl_map_;
 
-Decl::Decl(ID* id, DeclType decl_type) : id_(id), decl_type_(decl_type), attrlist_(0)
+Decl::Decl(ID* id, DeclType decl_type) : id_(id), decl_type_(decl_type), attrlist_(nullptr)
 	{
 	decl_map_[id_] = this;
 	if ( ! decl_list_ )
@@ -26,7 +26,7 @@ Decl::Decl(ID* id, DeclType decl_type) : id_(id), decl_type_(decl_type), attrlis
 
 	DEBUG_MSG("Finished Decl %s\n", id_->Name());
 
-	analyzer_context_ = 0;
+	analyzer_context_ = nullptr;
 	}
 
 Decl::~Decl()
@@ -119,7 +119,7 @@ Decl* Decl::LookUpDecl(const ID* id)
 	{
 	DeclMap::iterator it = decl_map_.find(id);
 	if ( it == decl_map_.end() )
-		return 0;
+		return nullptr;
 	return it->second;
 	}
 
diff --git a/tools/binpac/src/pac_decl.h b/tools/binpac/src/pac_decl.h
index 4602fdac50..5e806389c8 100644
--- a/tools/binpac/src/pac_decl.h
+++ b/tools/binpac/src/pac_decl.h
@@ -30,7 +30,7 @@ public:
 	AnalyzerContextDecl* analyzer_context() const { return analyzer_context_; }
 
 	// NULL except for TypeDecl or AnalyzerDecl
-	virtual Env* env() const { return 0; }
+	virtual Env* env() const { return nullptr; }
 
 	virtual void Prepare() = 0;
 
diff --git a/tools/binpac/src/pac_embedded.cc b/tools/binpac/src/pac_embedded.cc
index 1c07c6a218..9c10c594e2 100644
--- a/tools/binpac/src/pac_embedded.cc
+++ b/tools/binpac/src/pac_embedded.cc
@@ -4,7 +4,7 @@
 #include "pac_output.h"
 #include "pac_primitive.h"
 
-EmbeddedCodeSegment::EmbeddedCodeSegment(const string& s) : s_(s), primitive_(0) { }
+EmbeddedCodeSegment::EmbeddedCodeSegment(const string& s) : s_(s), primitive_(nullptr) { }
 
 EmbeddedCodeSegment::EmbeddedCodeSegment(PacPrimitive* primitive)
 	: s_(""), primitive_(primitive) { }
diff --git a/tools/binpac/src/pac_enum.cc b/tools/binpac/src/pac_enum.cc
index f58dad5d86..d52b9ea32e 100644
--- a/tools/binpac/src/pac_enum.cc
+++ b/tools/binpac/src/pac_enum.cc
@@ -32,7 +32,7 @@ EnumDecl::EnumDecl(ID* id, EnumList* enumlist) : Decl(id, ENUM), enumlist_(enuml
 	{
 	ID* type_id = id->clone();
 	datatype_ = new ExternType(type_id, ExternType::NUMBER);
-	extern_typedecl_ = new TypeDecl(type_id, 0, datatype_);
+	extern_typedecl_ = new TypeDecl(type_id, nullptr, datatype_);
 	}
 
 EnumDecl::~EnumDecl()
diff --git a/tools/binpac/src/pac_expr.cc b/tools/binpac/src/pac_expr.cc
index f45b6c3344..ca51b0282d 100644
--- a/tools/binpac/src/pac_expr.cc
+++ b/tools/binpac/src/pac_expr.cc
@@ -53,16 +53,16 @@ static const char* expr_fmt[] = {
 
 void Expr::init()
 	{
-	id_ = 0;
-	num_ = 0;
-	cstr_ = 0;
-	regex_ = 0;
+	id_ = nullptr;
+	num_ = nullptr;
+	cstr_ = nullptr;
+	regex_ = nullptr;
 	num_operands_ = 0;
-	operand_[0] = 0;
-	operand_[1] = 0;
-	operand_[2] = 0;
-	args_ = 0;
-	cases_ = 0;
+	operand_[0] = nullptr;
+	operand_[1] = nullptr;
+	operand_[2] = nullptr;
+	args_ = nullptr;
+	cases_ = nullptr;
 	}
 
 Expr::Expr(ID* arg_id) : DataDepElement(EXPR)
@@ -117,7 +117,7 @@ Expr::Expr(ExprType arg_type, Expr* op1, Expr* op2) : DataDepElement(EXPR)
 	num_operands_ = 2;
 	operand_[0] = op1;
 	operand_[1] = op2;
-	operand_[2] = 0;
+	operand_[2] = nullptr;
 	orig_ = strfmt(expr_fmt[expr_type_], op1->orig(), op2->orig());
 	}
 
@@ -244,7 +244,7 @@ void Expr::GenCaseEval(Output* out_cc, Env* env)
 	out_cc->inc_indent();
 	out_cc->println("{");
 
-	CaseExpr* default_case = 0;
+	CaseExpr* default_case = nullptr;
 	foreach (i, CaseExprList, cases_)
 		{
 		CaseExpr* c = *i;
@@ -266,7 +266,7 @@ void Expr::GenCaseEval(Output* out_cc, Env* env)
 		}
 
 	// Generate the default case after all other cases
-	GenCaseStr(0, out_cc, env, switch_type);
+	GenCaseStr(nullptr, out_cc, env, switch_type);
 	out_cc->inc_indent();
 	if ( default_case )
 		{
@@ -351,14 +351,14 @@ void Expr::GenEval(Output* out_cc, Env* env)
 
 			try
 				{
-				if ( (rf = GetRecordField(id, env)) != 0 )
+				if ( (rf = GetRecordField(id, env)) != nullptr )
 					{
 					str_ = strfmt("%s", rf->FieldSize(out_cc, env));
 					}
 				}
 			catch ( ExceptionIDNotFound& e )
 				{
-				if ( (ty = TypeDecl::LookUpType(id)) != 0 )
+				if ( (ty = TypeDecl::LookUpType(id)) != nullptr )
 					{
 					int ty_size = ty->StaticSize(global_env());
 					if ( ty_size >= 0 )
@@ -461,7 +461,7 @@ Type* Expr::DataType(Env* env) const
 			// Get type of the parent
 			Type* parent_type = operand_[0]->DataType(env);
 			if ( ! parent_type )
-				return 0;
+				return nullptr;
 			data_type = parent_type->MemberDataType(operand_[1]->id());
 			}
 			break;
@@ -501,7 +501,7 @@ Type* Expr::DataType(Env* env) const
 			if ( cases_ && ! cases_->empty() )
 				{
 				Type* type1 = cases_->front()->value()->DataType(env);
-				Type* numeric_with_largest_width = 0;
+				Type* numeric_with_largest_width = nullptr;
 
 				foreach (i, CaseExprList, cases_)
 					{
@@ -544,7 +544,7 @@ Type* Expr::DataType(Env* env) const
 				data_type = numeric_with_largest_width ? numeric_with_largest_width : type1;
 				}
 			else
-				data_type = 0;
+				data_type = nullptr;
 			}
 			break;
 
@@ -575,7 +575,7 @@ Type* Expr::DataType(Env* env) const
 			break;
 
 		default:
-			data_type = 0;
+			data_type = nullptr;
 			break;
 		}
 
@@ -812,7 +812,7 @@ int Expr::MinimalHeaderSize(Env* env)
 			RecordField* rf;
 			Type* ty;
 
-			if ( (rf = GetRecordField(id, env)) != 0 )
+			if ( (rf = GetRecordField(id, env)) != nullptr )
 				{
 				if ( rf->StaticSize(env, -1) >= 0 )
 					mhs = 0;
@@ -820,7 +820,7 @@ int Expr::MinimalHeaderSize(Env* env)
 					mhs = mhs_recordfield(env, rf);
 				}
 
-			else if ( (ty = TypeDecl::LookUpType(id)) != 0 )
+			else if ( (ty = TypeDecl::LookUpType(id)) != nullptr )
 				{
 				mhs = 0;
 				}
diff --git a/tools/binpac/src/pac_field.cc b/tools/binpac/src/pac_field.cc
index 36205ba8a0..dc9fd81fb1 100644
--- a/tools/binpac/src/pac_field.cc
+++ b/tools/binpac/src/pac_field.cc
@@ -11,7 +11,7 @@ Field::Field(FieldType tof, int flags, ID* id, Type* type)
 	{
 	decl_id_ = current_decl_id;
 	field_id_str_ = strfmt("%s:%s", decl_id()->Name(), id_->Name());
-	attrs_ = 0;
+	attrs_ = nullptr;
 	}
 
 Field::~Field()
diff --git a/tools/binpac/src/pac_flow.cc b/tools/binpac/src/pac_flow.cc
index 23406024ba..ddf6029b01 100644
--- a/tools/binpac/src/pac_flow.cc
+++ b/tools/binpac/src/pac_flow.cc
@@ -18,9 +18,9 @@
 FlowDecl::FlowDecl(ID* id, ParamList* params, AnalyzerElementList* elemlist)
 	: AnalyzerDecl(id, FLOW, params)
 	{
-	dataunit_ = 0;
-	conn_decl_ = 0;
-	flow_buffer_var_field_ = 0;
+	dataunit_ = nullptr;
+	conn_decl_ = nullptr;
+	flow_buffer_var_field_ = nullptr;
 	AddElements(elemlist);
 	}
 
@@ -30,13 +30,13 @@ FlowDecl::~FlowDecl()
 	delete dataunit_;
 	}
 
-ParameterizedType* FlowDecl::flow_buffer_type_ = 0;
+ParameterizedType* FlowDecl::flow_buffer_type_ = nullptr;
 
 ParameterizedType* FlowDecl::flow_buffer_type()
 	{
 	if ( ! flow_buffer_type_ )
 		{
-		flow_buffer_type_ = new ParameterizedType(new ID(kFlowBufferClass), 0);
+		flow_buffer_type_ = new ParameterizedType(new ID(kFlowBufferClass), nullptr);
 		}
 	return flow_buffer_type_;
 	}
@@ -141,7 +141,7 @@ void FlowDecl::GenEOFFunc(Output* out_h, Output* out_cc)
 
 	foreach (i, AnalyzerHelperList, eof_helpers_)
 		{
-		(*i)->GenCode(0, out_cc, this);
+		(*i)->GenCode(nullptr, out_cc, this);
 		}
 
 	if ( dataunit_->type() == AnalyzerDataUnit::FLOWUNIT )
@@ -268,7 +268,7 @@ void FlowDecl::GenCodeFlowUnit(Output* out_cc)
 	out_cc->println("}");
 	out_cc->dec_indent();
 
-	DataPtr data(env_, 0, 0);
+	DataPtr data(env_, nullptr, 0);
 	unit_datatype->GenParseCode(out_cc, env_, data, 0);
 
 	out_cc->println("if ( %s )", unit_datatype->parsing_complete(env_).c_str());
diff --git a/tools/binpac/src/pac_func.cc b/tools/binpac/src/pac_func.cc
index 40894621cb..9770be4747 100644
--- a/tools/binpac/src/pac_func.cc
+++ b/tools/binpac/src/pac_func.cc
@@ -7,10 +7,10 @@
 #include "pac_type.h"
 
 Function::Function(ID* id, Type* type, ParamList* params)
-	: id_(id), type_(type), params_(params), expr_(0), code_(0)
+	: id_(id), type_(type), params_(params), expr_(nullptr), code_(nullptr)
 	{
-	analyzer_decl_ = 0;
-	env_ = 0;
+	analyzer_decl_ = nullptr;
+	env_ = nullptr;
 	}
 
 Function::~Function()
diff --git a/tools/binpac/src/pac_id.cc b/tools/binpac/src/pac_id.cc
index 1d4002b114..15a0d7c12d 100644
--- a/tools/binpac/src/pac_id.cc
+++ b/tools/binpac/src/pac_id.cc
@@ -7,34 +7,34 @@
 #include "pac_type.h"
 #include "pac_utils.h"
 
-const ID* default_value_var = 0;
-const ID* null_id = 0;
-const ID* null_byteseg_id = 0;
-const ID* null_decl_id = 0;
-const ID* begin_of_data = 0;
-const ID* end_of_data = 0;
-const ID* len_of_data = 0;
-const ID* byteorder_id = 0;
-const ID* bigendian_id = 0;
-const ID* littleendian_id = 0;
-const ID* unspecified_byteorder_id = 0;
-const ID* const_true_id = 0;
-const ID* const_false_id = 0;
-const ID* analyzer_context_id = 0;
-const ID* context_macro_id = 0;
-const ID* this_id = 0;
-const ID* sourcedata_id = 0;
-const ID* connection_id = 0;
-const ID* upflow_id = 0;
-const ID* downflow_id = 0;
-const ID* dataunit_id = 0;
-const ID* flow_buffer_id = 0;
-const ID* element_macro_id = 0;
-const ID* input_macro_id = 0;
-const ID* cxt_connection_id = 0;
-const ID* cxt_flow_id = 0;
-const ID* parsing_state_id = 0;
-const ID* buffering_state_id = 0;
+const ID* default_value_var = nullptr;
+const ID* null_id = nullptr;
+const ID* null_byteseg_id = nullptr;
+const ID* null_decl_id = nullptr;
+const ID* begin_of_data = nullptr;
+const ID* end_of_data = nullptr;
+const ID* len_of_data = nullptr;
+const ID* byteorder_id = nullptr;
+const ID* bigendian_id = nullptr;
+const ID* littleendian_id = nullptr;
+const ID* unspecified_byteorder_id = nullptr;
+const ID* const_true_id = nullptr;
+const ID* const_false_id = nullptr;
+const ID* analyzer_context_id = nullptr;
+const ID* context_macro_id = nullptr;
+const ID* this_id = nullptr;
+const ID* sourcedata_id = nullptr;
+const ID* connection_id = nullptr;
+const ID* upflow_id = nullptr;
+const ID* downflow_id = nullptr;
+const ID* dataunit_id = nullptr;
+const ID* flow_buffer_id = nullptr;
+const ID* element_macro_id = nullptr;
+const ID* input_macro_id = nullptr;
+const ID* cxt_connection_id = nullptr;
+const ID* cxt_flow_id = nullptr;
+const ID* parsing_state_id = nullptr;
+const ID* buffering_state_id = nullptr;
 
 int ID::anonymous_id_seq = 0;
 
@@ -48,7 +48,7 @@ ID* ID::NewAnonymousID(const string& prefix)
 IDRecord::IDRecord(Env* arg_env, const ID* arg_id, IDType arg_id_type)
 	: env(arg_env), id(arg_id), id_type(arg_id_type)
 	{
-	eval = 0;
+	eval = nullptr;
 	evaluated = in_evaluation = false;
 	setfunc = ""; // except for STATE_VAR
 	switch ( id_type )
@@ -91,10 +91,11 @@ IDRecord::IDRecord(Env* arg_env, const ID* arg_id, IDType arg_id_type)
 			lvalue = "@FUNC_PARAM@";
 			break;
 		}
-	data_type = 0;
-	field = 0;
+
+	data_type = nullptr;
+	field = nullptr;
 	constant = constant_set = false;
-	macro = 0;
+	macro = nullptr;
 	}
 
 IDRecord::~IDRecord() { }
@@ -156,7 +157,7 @@ void IDRecord::Evaluate(Output* out, Env* env)
 const char* IDRecord::RValue() const
 	{
 	if ( id_type == MACRO )
-		return macro->EvalExpr(0, env);
+		return macro->EvalExpr(nullptr, env);
 
 	if ( id_type == TEMP_VAR && ! evaluated )
 		throw ExceptionIDNotEvaluated(id);
@@ -238,7 +239,7 @@ IDRecord* Env::lookup(const ID* id, bool recursive, bool raise_exception) const
 	if ( raise_exception )
 		throw ExceptionIDNotFound(id);
 	else
-		return 0;
+		return nullptr;
 	}
 
 IDType Env::GetIDType(const ID* id) const
@@ -334,7 +335,7 @@ Type* Env::GetDataType(const ID* id) const
 	if ( r )
 		return r->GetDataType();
 	else
-		return 0;  
+		return nullptr;
 	}
 
 string Env::DataTypeStr(const ID* id) const
@@ -405,11 +406,11 @@ void init_builtin_identifiers()
 
 Env* global_env()
 	{
-	static Env* the_global_env = 0;
+	static Env* the_global_env = nullptr;
 
 	if ( ! the_global_env )
 		{
-		the_global_env = new Env(0, 0);
+		the_global_env = new Env(nullptr, nullptr);
 
 		// These two are defined in binpac.h, so we do not need to
 		// generate code for them.
diff --git a/tools/binpac/src/pac_main.cc b/tools/binpac/src/pac_main.cc
index c54eabea4b..bea647a550 100644
--- a/tools/binpac/src/pac_main.cc
+++ b/tools/binpac/src/pac_main.cc
@@ -22,8 +22,8 @@ bool FLAGS_quiet = false;
 string FLAGS_output_directory;
 vector<string> FLAGS_include_directories;
 
-Output* header_output = 0;
-Output* source_output = 0;
+Output* header_output = nullptr;
+Output* source_output = nullptr;
 
 void add_to_include_directories(string dirs)
 	{
@@ -182,8 +182,8 @@ int compile(const char* filename)
 		exit(1);
 		}
 
-	header_output = 0;
-	source_output = 0;
+	header_output = nullptr;
+	source_output = nullptr;
 	input_filename = "";
 	fclose(fp_input);
 
diff --git a/tools/binpac/src/pac_paramtype.cc b/tools/binpac/src/pac_paramtype.cc
index a5fd579e8c..7fe61fe128 100644
--- a/tools/binpac/src/pac_paramtype.cc
+++ b/tools/binpac/src/pac_paramtype.cc
@@ -50,7 +50,7 @@ Type* ParameterizedType::MemberDataType(const ID* member_id) const
 	{
 	Type* ref_type = TypeDecl::LookUpType(type_id_);
 	if ( ! ref_type )
-		return 0;
+		return nullptr;
 	return ref_type->MemberDataType(member_id);
 	}
 
diff --git a/tools/binpac/src/pac_primitive.cc b/tools/binpac/src/pac_primitive.cc
index 51398340a6..2a5f47a2ee 100644
--- a/tools/binpac/src/pac_primitive.cc
+++ b/tools/binpac/src/pac_primitive.cc
@@ -8,13 +8,13 @@
 string PPVal::ToCode(Env* env)
 	{
 	ASSERT(expr_);
-	return string(expr_->EvalExpr(0, env));
+	return string(expr_->EvalExpr(nullptr, env));
 	}
 
 string PPSet::ToCode(Env* env)
 	{
 	ASSERT(expr_);
-	return expr_->SetFunc(0, env);
+	return expr_->SetFunc(nullptr, env);
 	}
 
 string PPType::ToCode(Env* env)
@@ -30,5 +30,5 @@ string PPConstDef::ToCode(Env* env)
 	env->SetEvaluated(id_);
 
 	string type_str = type->DataTypeStr();
-	return strfmt("%s %s = %s", type_str.c_str(), env->LValue(id_), expr_->EvalExpr(0, env));
+	return strfmt("%s %s = %s", type_str.c_str(), env->LValue(id_), expr_->EvalExpr(nullptr, env));
 	}
diff --git a/tools/binpac/src/pac_record.cc b/tools/binpac/src/pac_record.cc
index 9b9f9e17df..266dfc6dcf 100644
--- a/tools/binpac/src/pac_record.cc
+++ b/tools/binpac/src/pac_record.cc
@@ -15,7 +15,7 @@
 RecordType::RecordType(RecordFieldList* record_fields) : Type(RECORD)
 	{
 	// Here we assume that the type is a standalone type.
-	value_var_ = 0;
+	value_var_ = nullptr;
 
 	// Put all fields in fields_
 	foreach (i, RecordFieldList, record_fields)
@@ -24,7 +24,7 @@ RecordType::RecordType(RecordFieldList* record_fields) : Type(RECORD)
 	// Put RecordField's in record_fields_
 	record_fields_ = record_fields;
 
-	parsing_dataptr_var_field_ = 0;
+	parsing_dataptr_var_field_ = nullptr;
 	}
 
 RecordType::~RecordType()
@@ -37,7 +37,7 @@ RecordType::~RecordType()
 
 const ID* RecordType::parsing_dataptr_var() const
 	{
-	return parsing_dataptr_var_field_ ? parsing_dataptr_var_field_->id() : 0;
+	return parsing_dataptr_var_field_ ? parsing_dataptr_var_field_->id() : nullptr;
 	}
 
 bool RecordType::DefineValueVar() const
@@ -55,7 +55,7 @@ void RecordType::Prepare(Env* env, int flags)
 	{
 	ASSERT(flags & TO_BE_PARSED);
 
-	RecordField* prev = 0;
+	RecordField* prev = nullptr;
 	int offset = 0;
 	int seq = 0;
 	foreach (i, RecordFieldList, record_fields_)
@@ -237,14 +237,14 @@ bool RecordType::ByteOrderSensitive() const
 RecordField::RecordField(FieldType tof, ID* id, Type* type)
 	: Field(tof, TYPE_TO_BE_PARSED | CLASS_MEMBER | PUBLIC_READABLE, id, type)
 	{
-	begin_of_field_dataptr = 0;
-	end_of_field_dataptr = 0;
-	field_size_expr = 0;
-	field_offset_expr = 0;
-	end_of_field_dataptr_var = 0;
-	record_type_ = 0;
-	prev_ = 0;
-	next_ = 0;
+	begin_of_field_dataptr = nullptr;
+	end_of_field_dataptr = nullptr;
+	field_size_expr = nullptr;
+	field_offset_expr = nullptr;
+	end_of_field_dataptr_var = nullptr;
+	record_type_ = nullptr;
+	prev_ = nullptr;
+	next_ = nullptr;
 	static_offset_ = -1;
 	parsing_state_seq_ = 0;
 	boundary_checked_ = false;
@@ -399,7 +399,7 @@ void RecordDataField::GenParseCode(Output* out_cc, Env* env)
 	if ( record_type()->incremental_parsing() && prev() )
 		prev()->GenParseCode(out_cc, env);
 
-	DataPtr data(env, 0, 0);
+	DataPtr data(env, nullptr, 0);
 	if ( ! record_type()->incremental_parsing() )
 		{
 		data = getFieldBegin(out_cc, env);
@@ -499,7 +499,7 @@ bool RecordDataField::RequiresAnalyzerContext() const
 	}
 
 RecordPaddingField::RecordPaddingField(ID* id, PaddingType ptype, Expr* expr)
-	: RecordField(PADDING_FIELD, id, 0), ptype_(ptype), expr_(expr)
+	: RecordField(PADDING_FIELD, id, nullptr), ptype_(ptype), expr_(expr)
 	{
 	wordsize_ = -1;
 	}
diff --git a/tools/binpac/src/pac_record.h b/tools/binpac/src/pac_record.h
index fa3cf80051..7df944e4db 100644
--- a/tools/binpac/src/pac_record.h
+++ b/tools/binpac/src/pac_record.h
@@ -40,7 +40,7 @@ protected:
 	void DoGenParseCode(Output* out, Env* env, const DataPtr& data, int flags);
 	void GenDynamicSize(Output* out, Env* env, const DataPtr& data);
 
-	Type* DoClone() const { return 0; }
+	Type* DoClone() const { return nullptr; }
 
 	void DoMarkIncrementalInput();
 
diff --git a/tools/binpac/src/pac_strtype.cc b/tools/binpac/src/pac_strtype.cc
index 39169c37bf..6fa64bf31b 100644
--- a/tools/binpac/src/pac_strtype.cc
+++ b/tools/binpac/src/pac_strtype.cc
@@ -15,18 +15,19 @@
 const char* StringType::kStringTypeName = "bytestring";
 const char* StringType::kConstStringTypeName = "const_bytestring";
 
-StringType::StringType(StringTypeEnum anystr) : Type(STRING), type_(ANYSTR), str_(0), regex_(0)
+StringType::StringType(StringTypeEnum anystr)
+	: Type(STRING), type_(ANYSTR), str_(nullptr), regex_(nullptr)
 	{
 	ASSERT(anystr == ANYSTR);
 	init();
 	}
 
-StringType::StringType(ConstString* str) : Type(STRING), type_(CSTR), str_(str), regex_(0)
+StringType::StringType(ConstString* str) : Type(STRING), type_(CSTR), str_(str), regex_(nullptr)
 	{
 	init();
 	}
 
-StringType::StringType(RegEx* regex) : Type(STRING), type_(REGEX), str_(0), regex_(regex)
+StringType::StringType(RegEx* regex) : Type(STRING), type_(REGEX), str_(nullptr), regex_(regex)
 	{
 	ASSERT(regex_);
 	init();
@@ -34,7 +35,7 @@ StringType::StringType(RegEx* regex) : Type(STRING), type_(REGEX), str_(0), rege
 
 void StringType::init()
 	{
-	string_length_var_field_ = 0;
+	string_length_var_field_ = nullptr;
 	elem_datatype_ = new BuiltInType(BuiltInType::UINT8);
 	}
 
@@ -67,7 +68,7 @@ Type* StringType::DoClone() const
 			break;
 		default:
 			ASSERT(0);
-			return 0;
+			return nullptr;
 		}
 
 	return clone;
@@ -206,7 +207,7 @@ int StringType::StaticSize(Env* env) const
 
 const ID* StringType::string_length_var() const
 	{
-	return string_length_var_field_ ? string_length_var_field_->id() : 0;
+	return string_length_var_field_ ? string_length_var_field_->id() : nullptr;
 	}
 
 void StringType::GenDynamicSize(Output* out_cc, Env* env, const DataPtr& data)
diff --git a/tools/binpac/src/pac_type.cc b/tools/binpac/src/pac_type.cc
index dcf81b84a7..478c6e5826 100644
--- a/tools/binpac/src/pac_type.cc
+++ b/tools/binpac/src/pac_type.cc
@@ -24,23 +24,23 @@ Type::type_map_t Type::type_map_;
 
 Type::Type(TypeType tot) : DataDepElement(DataDepElement::TYPE), tot_(tot)
 	{
-	type_decl_ = 0;
+	type_decl_ = nullptr;
 	type_decl_id_ = current_decl_id;
 	declared_as_type_ = false;
-	env_ = 0;
+	env_ = nullptr;
 	value_var_ = default_value_var;
 	ASSERT(value_var_);
 	value_var_type_ = MEMBER_VAR;
 	anonymous_value_var_ = false;
-	size_var_field_ = 0;
-	size_expr_ = 0;
+	size_var_field_ = nullptr;
+	size_expr_ = nullptr;
 	boundary_checked_ = false;
-	parsing_complete_var_field_ = 0;
-	parsing_state_var_field_ = 0;
-	buffering_state_var_field_ = 0;
-	has_value_field_ = 0;
+	parsing_complete_var_field_ = nullptr;
+	parsing_state_var_field_ = nullptr;
+	buffering_state_var_field_ = nullptr;
+	has_value_field_ = nullptr;
 
-	array_until_input_ = 0;
+	array_until_input_ = nullptr;
 
 	incremental_input_ = false;
 	buffer_input_ = false;
@@ -49,16 +49,16 @@ Type::Type(TypeType tot) : DataDepElement(DataDepElement::TYPE), tot_(tot)
 	fields_ = new FieldList();
 
 	attrs_ = new AttrList();
-	attr_byteorder_expr_ = 0;
+	attr_byteorder_expr_ = nullptr;
 	attr_checks_ = new ExprList();
 	attr_enforces_ = new ExprList();
 	attr_chunked_ = false;
 	attr_exportsourcedata_ = false;
-	attr_if_expr_ = 0;
-	attr_length_expr_ = 0;
-	attr_letfields_ = 0;
-	attr_multiline_end_ = 0;
-	attr_linebreaker_ = 0;
+	attr_if_expr_ = nullptr;
+	attr_length_expr_ = nullptr;
+	attr_letfields_ = nullptr;
+	attr_multiline_end_ = nullptr;
+	attr_linebreaker_ = nullptr;
 	attr_oneline_ = false;
 	attr_refcount_ = false;
 	attr_requires_ = new ExprList();
@@ -139,7 +139,7 @@ void Type::set_value_var(const ID* arg_id, int arg_id_type)
 
 const ID* Type::size_var() const
 	{
-	return size_var_field_ ? size_var_field_->id() : 0;
+	return size_var_field_ ? size_var_field_->id() : nullptr;
 	}
 
 void Type::AddField(Field* f)
@@ -569,7 +569,7 @@ void Type::GenParseBuffer(Output* out_cc, Env* env, int flags)
 		data_begin = begin_of_data;
 		}
 	else
-		data_begin = 0;
+		data_begin = nullptr;
 
 	if ( array_until_input_ )
 		{
@@ -762,7 +762,7 @@ Type* Type::MemberDataType(const ID* member_id) const
 
 Type* Type::ElementDataType() const
 	{
-	return 0;
+	return nullptr;
 	}
 
 // Returns false if it is not necessary to add size_var
@@ -968,7 +968,7 @@ bool Type::Bufferable() const
 bool Type::BufferableWithLineBreaker() const
 	{
 	// If the input is an ASCII line with a given linebreaker;
-	return attr_linebreaker_ != 0;
+	return attr_linebreaker_ != nullptr;
 	}
 
 Expr* Type::LineBreaker() const
@@ -992,7 +992,7 @@ const ID* Type::parsing_complete_var() const
 	if ( parsing_complete_var_field_ )
 		return parsing_complete_var_field_->id();
 	else
-		return 0;
+		return nullptr;
 	}
 
 string Type::parsing_complete(Env* env) const
@@ -1006,7 +1006,7 @@ const ID* Type::has_value_var() const
 	if ( has_value_field_ )
 		return has_value_field_->id();
 	else
-		return 0;
+		return nullptr;
 	}
 
 int Type::InitialBufferLength() const
@@ -1095,7 +1095,7 @@ Type* Type::LookUpByID(ID* id)
 			}
 		}
 
-	return new ParameterizedType(id, 0);
+	return new ParameterizedType(id, nullptr);
 	}
 
 void Type::AddPredefinedType(const string& type_name, Type* type)
diff --git a/tools/binpac/src/pac_typedecl.cc b/tools/binpac/src/pac_typedecl.cc
index cb6238e059..bf99118be7 100644
--- a/tools/binpac/src/pac_typedecl.cc
+++ b/tools/binpac/src/pac_typedecl.cc
@@ -19,7 +19,7 @@
 TypeDecl::TypeDecl(ID* id, ParamList* params, Type* type)
 	: Decl(id, TYPE), params_(params), type_(type)
 	{
-	env_ = 0;
+	env_ = nullptr;
 	type_->set_type_decl(this, true);
 	}
 
@@ -222,8 +222,8 @@ void TypeDecl::GenDestructorFunc(Output* out_h, Output* out_cc)
 
 string TypeDecl::ParseFuncPrototype(Env* env)
 	{
-	const char* func_name = 0;
-	const char* return_type = 0;
+	const char* func_name = nullptr;
+	const char* return_type = nullptr;
 	string params;
 
 	if ( type_->incremental_input() )
@@ -268,7 +268,7 @@ void TypeDecl::GenParsingEnd(Output* out_cc, Env* env, const DataPtr& data)
 		}
 	else
 		{
-		ret_val_0 = type_->DataSize(0, env, data).c_str();
+		ret_val_0 = type_->DataSize(nullptr, env, data).c_str();
 		ret_val_1 = "@@@";
 
 		out_cc->println("BINPAC_ASSERT(%s + (%s) <= %s);", env->RValue(begin_of_data),
@@ -347,7 +347,7 @@ void TypeDecl::GenParseFunc(Output* out_h, Output* out_cc)
 	out_cc->inc_indent();
 	out_cc->println("{");
 
-	DataPtr data(env, 0, 0);
+	DataPtr data(env, nullptr, 0);
 
 	if ( ! type_->incremental_input() )
 		data = DataPtr(env, begin_of_data, 0);
@@ -378,7 +378,7 @@ Type* TypeDecl::LookUpType(const ID* id)
 	{
 	Decl* decl = LookUpDecl(id);
 	if ( ! decl )
-		return 0;
+		return nullptr;
 	switch ( decl->decl_type() )
 		{
 		case TYPE:
@@ -388,6 +388,6 @@ Type* TypeDecl::LookUpType(const ID* id)
 		case ENUM:
 			return static_cast<EnumDecl*>(decl)->DataType();
 		default:
-			return 0;
+			return nullptr;
 		}
 	}