Code style improvements (#1868)

* Use modern T p = v; notation to initialize class fields
* Use modern X() = default; notation for empty class constructors

23 files changed, 108 insertions, 102 deletions

diff --git a/src/cfg/Relooper.cpp b/src/cfg/Relooper.cpp
index bdb3f9008..3acdabd52 100644
--- a/src/cfg/Relooper.cpp
+++ b/src/cfg/Relooper.cpp
@@ -99,9 +99,9 @@ static wasm::Expression* HandleFollowupMultiples(wasm::Expression* Ret, Shape* P
 
 // Branch
 
-Branch::Branch(wasm::Expression* ConditionInit, wasm::Expression* CodeInit) : Ancestor(nullptr), Condition(ConditionInit), Code(CodeInit) {}
+Branch::Branch(wasm::Expression* ConditionInit, wasm::Expression* CodeInit) : Condition(ConditionInit), Code(CodeInit) {}
 
-Branch::Branch(std::vector<wasm::Index>&& ValuesInit, wasm::Expression* CodeInit) : Ancestor(nullptr), Condition(nullptr), Code(CodeInit) {
+Branch::Branch(std::vector<wasm::Index>&& ValuesInit, wasm::Expression* CodeInit) : Condition(nullptr), Code(CodeInit) {
   if (ValuesInit.size() > 0) {
     SwitchValues = wasm::make_unique<std::vector<wasm::Index>>(ValuesInit);
   }
@@ -124,7 +124,7 @@ wasm::Expression* Branch::Render(RelooperBuilder& Builder, Block* Target, bool S
 
 // Block
 
-Block::Block(wasm::Expression* CodeInit, wasm::Expression* SwitchConditionInit) : Parent(nullptr), Id(-1), Code(CodeInit), SwitchCondition(SwitchConditionInit), IsCheckedMultipleEntry(false) {}
+Block::Block(wasm::Expression* CodeInit, wasm::Expression* SwitchConditionInit) : Code(CodeInit), SwitchCondition(SwitchConditionInit), IsCheckedMultipleEntry(false) {}
 
 Block::~Block() {
   for (auto& iter : ProcessedBranchesOut) {
diff --git a/src/cfg/Relooper.h b/src/cfg/Relooper.h
index 162fd3149..5773721cd 100644
--- a/src/cfg/Relooper.h
+++ b/src/cfg/Relooper.h
@@ -82,7 +82,7 @@ struct Branch {
     Break = 1,
     Continue = 2
   };
-  Shape* Ancestor; // If not NULL, this shape is the relevant one for purposes of getting to the target block. We break or continue on it
+  Shape* Ancestor = nullptr; // If not NULL, this shape is the relevant one for purposes of getting to the target block. We break or continue on it
   Branch::FlowType Type; // If Ancestor is not NULL, this says whether to break or continue
 
   // A branch either has a condition expression if the block ends in ifs, or if the block ends in a switch, then a list of indexes, which
@@ -151,7 +151,7 @@ struct InsertOrderedSet
 
   size_t count(const T& val) const { return Map.count(val); }
 
-  InsertOrderedSet() {}
+  InsertOrderedSet() = default;
   InsertOrderedSet(const InsertOrderedSet& other) {
     *this = other;
   }
@@ -214,7 +214,7 @@ struct InsertOrderedMap
   bool empty() const { return Map.empty(); }
   size_t count(const Key& k) const { return Map.count(k); }
 
-  InsertOrderedMap() {}
+  InsertOrderedMap() = default;
   InsertOrderedMap(InsertOrderedMap& other) {
     abort(); // TODO, watch out for iterators
   }
@@ -245,8 +245,8 @@ struct Block {
   BlockSet BranchesIn;
   BlockBranchMap ProcessedBranchesOut;
   BlockSet ProcessedBranchesIn;
-  Shape* Parent; // The shape we are directly inside
-  int Id; // A unique identifier, defined when added to relooper
+  Shape* Parent = nullptr; // The shape we are directly inside
+  int Id = -1; // A unique identifier, defined when added to relooper
   wasm::Expression* Code; // The code in this block. This can be arbitrary wasm code, including internal control flow, it should just not branch to the outside
   wasm::Expression* SwitchCondition; // If nullptr, then this block ends in ifs (or nothing). otherwise, this block ends in a switch, done on this condition
   bool IsCheckedMultipleEntry; // If true, we are a multiple entry, so reaching us requires setting the label variable
@@ -296,8 +296,8 @@ struct MultipleShape;
 struct LoopShape;
 
 struct Shape {
-  int Id; // A unique identifier. Used to identify loops, labels are Lx where x is the Id. Defined when added to relooper
-  Shape* Next; // The shape that will appear in the code right after this one
+  int Id = -1; // A unique identifier. Used to identify loops, labels are Lx where x is the Id. Defined when added to relooper
+  Shape* Next = nullptr; // The shape that will appear in the code right after this one
   Shape* Natural; // The shape that control flow gets to naturally (if there is Next, then this is Next)
 
   enum ShapeType {
@@ -307,7 +307,7 @@ struct Shape {
   };
   ShapeType Type;
 
-  Shape(ShapeType TypeInit) : Id(-1), Next(NULL), Type(TypeInit) {}
+  Shape(ShapeType TypeInit) : Type(TypeInit) {}
   virtual ~Shape() = default;
 
   virtual wasm::Expression* Render(RelooperBuilder& Builder, bool InLoop) = 0;
@@ -318,9 +318,9 @@ struct Shape {
 };
 
 struct SimpleShape : public Shape {
-  Block* Inner;
+  Block* Inner = nullptr;
 
-  SimpleShape() : Shape(Simple), Inner(NULL) {}
+  SimpleShape() : Shape(Simple) {}
   wasm::Expression* Render(RelooperBuilder& Builder, bool InLoop) override;
 };
 
@@ -335,11 +335,11 @@ struct MultipleShape : public Shape {
 };
 
 struct LoopShape : public Shape {
-  Shape* Inner;
+  Shape* Inner = nullptr;
 
   BlockSet Entries; // we must visit at least one of these
 
-  LoopShape() : Shape(Loop), Inner(NULL) {}
+  LoopShape() : Shape(Loop) {}
   wasm::Expression* Render(RelooperBuilder& Builder, bool InLoop) override;
 };
 
diff --git a/src/emscripten-optimizer/istring.h b/src/emscripten-optimizer/istring.h
index 87da87473..5a7d05162 100644
--- a/src/emscripten-optimizer/istring.h
+++ b/src/emscripten-optimizer/istring.h
@@ -35,7 +35,7 @@
 namespace cashew {
 
 struct IString {
-  const char *str;
+  const char *str = nullptr;
 
   static size_t hash_c(const char *str) { // see http://www.cse.yorku.ca/~oz/hash.html
     unsigned int hash = 5381;
@@ -59,7 +59,7 @@ struct IString {
     }
   };
 
-  IString() : str(nullptr) {}
+  IString() = default;
   IString(const char *s, bool reuse=true) { // if reuse=true, then input is assumed to remain alive; not copied
     assert(s);
     set(s, reuse);
@@ -178,7 +178,7 @@ namespace cashew {
 class IStringSet : public std::unordered_set<IString> {
   std::vector<char> data;
 public:
-  IStringSet() {}
+  IStringSet() = default;
   IStringSet(const char *init) { // comma-delimited list
     int size = strlen(init) + 1;
     data.resize(size);
diff --git a/src/emscripten-optimizer/optimizer.h b/src/emscripten-optimizer/optimizer.h
index c3939abf4..12d7c1433 100644
--- a/src/emscripten-optimizer/optimizer.h
+++ b/src/emscripten-optimizer/optimizer.h
@@ -59,7 +59,7 @@ AsmType detectType(cashew::Ref node, AsmData *asmData=nullptr, bool inVarDef=fal
 
 struct AsmData {
   struct Local {
-    Local() {}
+    Local() = default;
     Local(AsmType type, bool param) : type(type), param(param) {}
     AsmType type;
     bool param; // false if a var
@@ -92,7 +92,7 @@ struct AsmData {
     return isLocal(name) && !locals[name].param;
   }
 
-  AsmData() {} // if you want to fill in the data yourself
+  AsmData() = default; // if you want to fill in the data yourself
   AsmData(cashew::Ref f); // if you want to read data from f, and modify it as you go (parallel to denormalize)
 
   void denormalize();
diff --git a/src/emscripten-optimizer/parser.h b/src/emscripten-optimizer/parser.h
index ae3c6b067..78ed27933 100644
--- a/src/emscripten-optimizer/parser.h
+++ b/src/emscripten-optimizer/parser.h
@@ -910,8 +910,8 @@ class Parser {
 
   // Debugging
 
-  char *allSource;
-  int allSize;
+  char *allSource = nullptr;
+  int allSize = 0;
 
   static void dump(const char *where, char* curr) {
     /*
@@ -938,7 +938,7 @@ class Parser {
 
 public:
 
-  Parser() : allSource(nullptr), allSize(0) {
+  Parser() {
     expressionPartsStack.resize(1);
   }
 
diff --git a/src/emscripten-optimizer/simple_ast.cpp b/src/emscripten-optimizer/simple_ast.cpp
index b3a3cae84..c9659f964 100644
--- a/src/emscripten-optimizer/simple_ast.cpp
+++ b/src/emscripten-optimizer/simple_ast.cpp
@@ -188,7 +188,7 @@ void dump(const char *str, Ref node, bool pretty) {
 // Traversals
 
 struct TraverseInfo {
-  TraverseInfo() {}
+  TraverseInfo() = default;
   TraverseInfo(Ref node, ArrayStorage* arr) : node(node), arr(arr), index(0) {}
   Ref node;
   ArrayStorage* arr;
@@ -199,10 +199,11 @@ template<class T, int init>
 struct StackedStack { // a stack, on the stack
   T stackStorage[init];
   T* storage;
-  int used, available; // used amount, available amount
-  bool alloced;
+  int used = 0;
+  int available = init; // used amount, available amount
+  bool alloced = false;
 
-  StackedStack() : used(0), available(init), alloced(false) {
+  StackedStack() {
     storage = stackStorage;
   }
   ~StackedStack() {
diff --git a/src/emscripten-optimizer/simple_ast.h b/src/emscripten-optimizer/simple_ast.h
index 9cbe7616c..de8122ba1 100644
--- a/src/emscripten-optimizer/simple_ast.h
+++ b/src/emscripten-optimizer/simple_ast.h
@@ -112,7 +112,7 @@ struct Value {
     AssignName_ = 7
   };
 
-  Type type;
+  Type type = Null;
 
   typedef std::unordered_map<IString, Ref> ObjectStorage;
 
@@ -131,14 +131,14 @@ struct Value {
   };
 
   // constructors all copy their input
-  Value() : type(Null), num(0) {}
-  explicit Value(const char *s) : type(Null) {
+  Value() {}
+  explicit Value(const char *s) {
     setString(s);
   }
-  explicit Value(double n) : type(Null) {
+  explicit Value(double n) {
     setNumber(n);
   }
-  explicit Value(ArrayStorage &a) : type(Null) {
+  explicit Value(ArrayStorage &a) {
     setArray();
     *arr = a;
   }
@@ -544,15 +544,16 @@ void traverseFunctions(Ref ast, std::function<void (Ref)> visit);
 struct JSPrinter {
   bool pretty, finalize;
 
-  char *buffer;
-  size_t size, used;
+  char *buffer = nullptr;
+  size_t size = 0;
+  size_t used = 0;
 
-  int indent;
-  bool possibleSpace; // add a space to separate identifiers
+  int indent = 0;
+  bool possibleSpace = false; // add a space to separate identifiers
 
   Ref ast;
 
-  JSPrinter(bool pretty_, bool finalize_, Ref ast_) : pretty(pretty_), finalize(finalize_), buffer(0), size(0), used(0), indent(0), possibleSpace(false), ast(ast_) {}
+  JSPrinter(bool pretty_, bool finalize_, Ref ast_) : pretty(pretty_), finalize(finalize_), ast(ast_) {}
 
   ~JSPrinter() {
     free(buffer);
diff --git a/src/ir/branch-utils.h b/src/ir/branch-utils.h
index 50c71e8c9..e8fd25119 100644
--- a/src/ir/branch-utils.h
+++ b/src/ir/branch-utils.h
@@ -149,10 +149,10 @@ struct BranchSeeker : public PostWalker<BranchSeeker> {
   Name target;
   bool named = true;
 
-  Index found;
+  Index found = 0;
   Type valueType;
 
-  BranchSeeker(Name target) : target(target), found(0) {}
+  BranchSeeker(Name target) : target(target) {}
 
   void noteFound(Expression* value) {
     found++;
diff --git a/src/ir/count.h b/src/ir/count.h
index 1fef3a870..d9c89b4ce 100644
--- a/src/ir/count.h
+++ b/src/ir/count.h
@@ -22,7 +22,7 @@ namespace wasm {
 struct GetLocalCounter : public PostWalker<GetLocalCounter> {
   std::vector<Index> num;
 
-  GetLocalCounter() {}
+  GetLocalCounter() = default;
   GetLocalCounter(Function* func) {
     analyze(func, func->body);
   }
diff --git a/src/pass.h b/src/pass.h
index 0a3d85e02..78d1f594e 100644
--- a/src/pass.h
+++ b/src/pass.h
@@ -49,7 +49,7 @@ private:
   struct PassInfo {
     std::string description;
     Creator create;
-    PassInfo() {}
+    PassInfo() = default;
     PassInfo(std::string description, Creator create) : description(description), create(create) {}
   };
   std::map<std::string, PassInfo> passInfos;
@@ -253,8 +253,8 @@ public:
   std::string name;
 
 protected:
-  Pass() {}
-  Pass(Pass &) {}
+  Pass() = default;
+  Pass(Pass &) = default;
   Pass &operator=(const Pass&) = delete;
 };
 
diff --git a/src/passes/Print.cpp b/src/passes/Print.cpp
index e544447fe..3de8b5c01 100644
--- a/src/passes/Print.cpp
+++ b/src/passes/Print.cpp
@@ -1350,7 +1350,7 @@ Pass *createPrinterPass() {
 
 class MinifiedPrinter : public Printer {
 public:
-  MinifiedPrinter() : Printer() {}
+  MinifiedPrinter() = default;
   MinifiedPrinter(std::ostream* o) : Printer(o) {}
 
   void run(PassRunner* runner, Module* module) override {
@@ -1368,7 +1368,7 @@ Pass *createMinifiedPrinterPass() {
 
 class FullPrinter : public Printer {
 public:
-  FullPrinter() : Printer() {}
+  FullPrinter() = default;
   FullPrinter(std::ostream* o) : Printer(o) {}
 
   void run(PassRunner* runner, Module* module) override {
@@ -1386,7 +1386,7 @@ Pass *createFullPrinterPass() {
 
 class PrintStackIR : public Printer {
 public:
-  PrintStackIR() : Printer() {}
+  PrintStackIR() = default;
   PrintStackIR(std::ostream* o) : Printer(o) {}
 
   void run(PassRunner* runner, Module* module) override {
diff --git a/src/shell-interface.h b/src/shell-interface.h
index 071cc614d..ad553441f 100644
--- a/src/shell-interface.h
+++ b/src/shell-interface.h
@@ -53,7 +53,7 @@ struct ShellExternalInterface : ModuleInstance::ExternalInterface {
     Memory& operator=(const Memory&) = delete;
 
    public:
-    Memory() {}
+    Memory() = default;
     void resize(size_t newSize) {
       // Ensure the smallest allocation is large enough that most allocators
       // will provide page-aligned storage. This hopefully allows the
diff --git a/src/support/archive.h b/src/support/archive.h
index 95af1ac94..0ca066ff1 100644
--- a/src/support/archive.h
+++ b/src/support/archive.h
@@ -71,7 +71,7 @@ class Archive {
     Child child;
     bool error = false;  // TODO: use std::error_code instead?
    public:
-    child_iterator() {}
+    child_iterator() = default;
     explicit child_iterator(bool error) : error(error) {}
     child_iterator(const Child& c) : child(c) {}
     const Child* operator->() const { return &child; }
diff --git a/src/support/json.h b/src/support/json.h
index 034cdc9b9..7ffa1211f 100644
--- a/src/support/json.h
+++ b/src/support/json.h
@@ -47,7 +47,7 @@ typedef cashew::IString IString;
 // Main value type
 struct Value {
   struct Ref : public std::shared_ptr<Value> {
-    Ref() : std::shared_ptr<Value>() {}
+    Ref() = default;
     Ref(Value* value) : std::shared_ptr<Value>(value) {}
 
     Ref& operator[](size_t x) {
@@ -67,7 +67,7 @@ struct Value {
     Object = 5,
   };
 
-  Type type;
+  Type type = Null;
 
   typedef std::vector<Ref> ArrayStorage;
   typedef std::unordered_map<IString, Ref> ObjectStorage;
@@ -79,7 +79,7 @@ struct Value {
 #ifndef _MSC_VER
     IString str;
 #endif
-    double num;
+    double num = 0;
     ArrayStorage *arr; // manually allocated/freed
     bool boo;
     ObjectStorage *obj; // manually allocated/freed
@@ -87,7 +87,7 @@ struct Value {
   };
 
   // constructors all copy their input
-  Value() : type(Null), num(0) {}
+  Value() {}
   explicit Value(const char *s) : type(Null) {
     setString(s);
   }
diff --git a/src/support/sorted_vector.h b/src/support/sorted_vector.h
index 8f33de03a..da991ce78 100644
--- a/src/support/sorted_vector.h
+++ b/src/support/sorted_vector.h
@@ -26,7 +26,7 @@
 namespace wasm {
 
 struct SortedVector : public std::vector<Index> {
-  SortedVector() {}
+  SortedVector() = default;
 
   SortedVector merge(const SortedVector& other) const {
     SortedVector ret;
diff --git a/src/tools/wasm-metadce.cpp b/src/tools/wasm-metadce.cpp
index 5caf8fea7..f06c41882 100644
--- a/src/tools/wasm-metadce.cpp
+++ b/src/tools/wasm-metadce.cpp
@@ -42,7 +42,7 @@ using namespace wasm;
 struct DCENode {
   Name name;
   std::vector<Name> reaches; // the other nodes this one can reach
-  DCENode() {}
+  DCENode() = default;
   DCENode(Name name) : name(name) {}
 };
 
diff --git a/src/tools/wasm-reduce.cpp b/src/tools/wasm-reduce.cpp
index 02174bb8a..8b12c0ef1 100644
--- a/src/tools/wasm-reduce.cpp
+++ b/src/tools/wasm-reduce.cpp
@@ -79,7 +79,7 @@ struct ProgramResult {
   std::string output;
   double time;
 
-  ProgramResult() {}
+  ProgramResult() = default;
   ProgramResult(std::string command) {
     getFromExecution(command);
   }
diff --git a/src/wasm-binary.h b/src/wasm-binary.h
index 998952bde..a5b1e10b4 100644
--- a/src/wasm-binary.h
+++ b/src/wasm-binary.h
@@ -55,7 +55,7 @@ struct LEB {
 
   T value;
 
-  LEB() {}
+  LEB() = default;
   LEB(T value) : value(value) {}
 
   bool hasMore(T temp, MiniT byte) {
diff --git a/src/wasm-interpreter.h b/src/wasm-interpreter.h
index c5a08cc9b..b10f3087f 100644
--- a/src/wasm-interpreter.h
+++ b/src/wasm-interpreter.h
@@ -53,7 +53,7 @@ enum {
 // Stuff that flows around during executing expressions: a literal, or a change in control flow.
 class Flow {
 public:
-  Flow() {}
+  Flow() = default;
   Flow(Literal value) : value(value) {}
   Flow(Name breakTo) : breakTo(breakTo) {}
 
diff --git a/src/wasm-s-parser.h b/src/wasm-s-parser.h
index 0845fa70e..ef6e8d36b 100644
--- a/src/wasm-s-parser.h
+++ b/src/wasm-s-parser.h
@@ -44,24 +44,25 @@ public:
 class Element {
   typedef ArenaVector<Element*> List;
 
-  bool isList_;
+  bool isList_ = true;
   List list_;
   cashew::IString str_;
   bool dollared_;
   bool quoted_;
 
 public:
-  Element(MixedArena& allocator) : isList_(true), list_(allocator), line(-1), col(-1), startLoc(nullptr), endLoc(nullptr) {}
+  Element(MixedArena& allocator) : list_(allocator) {}
 
   bool isList() const { return isList_; }
   bool isStr() const { return !isList_; }
   bool dollared() const { return isStr() && dollared_; }
   bool quoted() const { return isStr() && quoted_; }
 
-  size_t line, col;
+  size_t line = -1;
+  size_t col  = -1;
   // original locations at the start/end of the S-Expression list
-  SourceLocation* startLoc;
-  SourceLocation* endLoc;
+  SourceLocation* startLoc = nullptr;
+  SourceLocation* endLoc = nullptr;
 
   // list methods
   List& list();
@@ -88,7 +89,7 @@ class SExpressionParser {
   char* input;
   size_t line;
   char* lineStart;
-  SourceLocation* loc;
+  SourceLocation* loc = nullptr;
 
   MixedArena allocator;
 
@@ -114,7 +115,7 @@ class SExpressionWasmBuilder {
   std::vector<Name> functionTypeNames;
   std::vector<Name> globalNames;
   int functionCounter;
-  int globalCounter;
+  int globalCounter = 0;
   std::map<Name, Type> functionTypes; // we need to know function return types before we parse their contents
   std::unordered_map<cashew::IString, Index> debugInfoFileIndices;
 
diff --git a/src/wasm-traversal.h b/src/wasm-traversal.h
index c79be1c10..fe3e3c5dd 100644
--- a/src/wasm-traversal.h
+++ b/src/wasm-traversal.h
@@ -671,7 +671,7 @@ struct PostWalker : public Walker<SubType, VisitorType> {
 
 template<typename SubType, typename VisitorType = Visitor<SubType>>
 struct ControlFlowWalker : public PostWalker<SubType, VisitorType> {
-  ControlFlowWalker() {}
+  ControlFlowWalker() = default;
 
   std::vector<Expression*> controlFlowStack; // contains blocks, loops, and ifs
 
@@ -734,7 +734,7 @@ struct ControlFlowWalker : public PostWalker<SubType, VisitorType> {
 
 template<typename SubType, typename VisitorType = Visitor<SubType>>
 struct ExpressionStackWalker : public PostWalker<SubType, VisitorType> {
-  ExpressionStackWalker() {}
+  ExpressionStackWalker() = default;
 
   std::vector<Expression*> expressionStack;
 
@@ -798,7 +798,7 @@ struct ExpressionStackWalker : public PostWalker<SubType, VisitorType> {
 
 template<typename SubType, typename VisitorType = Visitor<SubType>>
 struct LinearExecutionWalker : public PostWalker<SubType, VisitorType> {
-  LinearExecutionWalker() {}
+  LinearExecutionWalker() = default;
 
   // subclasses should implement this
   void noteNonLinear(Expression* curr) { abort(); }
diff --git a/src/wasm.h b/src/wasm.h
index ec8722ad0..dc24b0f1c 100644
--- a/src/wasm.h
+++ b/src/wasm.h
@@ -259,9 +259,10 @@ public:
   };
   Id _id;
 
-  Type type; // the type of the expression: its *output*, not necessarily its input(s)
+  // the type of the expression: its *output*, not necessarily its input(s)
+  Type type = none;
 
-  Expression(Id id) : _id(id), type(none) {}
+  Expression(Id id) : _id(id) {}
 
   void finalize() {}
 
@@ -298,7 +299,7 @@ public:
 
 class Nop : public SpecificExpression<Expression::NopId> {
 public:
-  Nop() {}
+  Nop() = default;
   Nop(MixedArena& allocator) {}
 };
 
@@ -345,7 +346,7 @@ public:
 
 class Loop : public SpecificExpression<Expression::LoopId> {
 public:
-  Loop() {}
+  Loop() = default;
   Loop(MixedArena& allocator) {}
 
   Name name;
@@ -376,14 +377,14 @@ public:
 
 class Switch : public SpecificExpression<Expression::SwitchId> {
 public:
-  Switch(MixedArena& allocator) : targets(allocator), condition(nullptr), value(nullptr) {
+  Switch(MixedArena& allocator) : targets(allocator) {
     type = unreachable;
   }
 
   ArenaVector<Name> targets;
   Name default_;
-  Expression* condition;
-  Expression* value;
+  Expression* condition = nullptr;
+  Expression* value = nullptr;
 
   void finalize();
 };
@@ -401,10 +402,10 @@ public:
 class FunctionType {
 public:
   Name name;
-  Type result;
+  Type result = none;
   std::vector<Type> params;
 
-  FunctionType() : result(none) {}
+  FunctionType() = default;
 
   bool structuralComparison(FunctionType& b);
 
@@ -425,7 +426,7 @@ public:
 
 class GetLocal : public SpecificExpression<Expression::GetLocalId> {
 public:
-  GetLocal() {}
+  GetLocal() = default;
   GetLocal(MixedArena& allocator) {}
 
   Index index;
@@ -433,7 +434,7 @@ public:
 
 class SetLocal : public SpecificExpression<Expression::SetLocalId> {
 public:
-  SetLocal() {}
+  SetLocal() = default;
   SetLocal(MixedArena& allocator) {}
 
   void finalize();
@@ -447,7 +448,7 @@ public:
 
 class GetGlobal : public SpecificExpression<Expression::GetGlobalId> {
 public:
-  GetGlobal() {}
+  GetGlobal() = default;
   GetGlobal(MixedArena& allocator) {}
 
   Name name;
@@ -455,7 +456,7 @@ public:
 
 class SetGlobal : public SpecificExpression<Expression::SetGlobalId> {
 public:
-  SetGlobal() {}
+  SetGlobal() = default;
   SetGlobal(MixedArena& allocator) {}
 
   Name name;
@@ -466,7 +467,7 @@ public:
 
 class Load : public SpecificExpression<Expression::LoadId> {
 public:
-  Load() {}
+  Load() = default;
   Load(MixedArena& allocator) {}
 
   uint8_t bytes;
@@ -483,7 +484,7 @@ public:
 
 class Store : public SpecificExpression<Expression::StoreId> {
 public:
-  Store() : valueType(none) {}
+  Store() = default;
   Store(MixedArena& allocator) : Store() {}
 
   uint8_t bytes;
@@ -492,7 +493,7 @@ public:
   bool isAtomic;
   Expression* ptr;
   Expression* value;
-  Type valueType; // the store never returns a value
+  Type valueType;
 
   void finalize();
 };
@@ -614,7 +615,7 @@ class SIMDShift : public SpecificExpression<Expression::SIMDShiftId> {
 
 class Const : public SpecificExpression<Expression::ConstId> {
 public:
-  Const() {}
+  Const() = default;
   Const(MixedArena& allocator) {}
 
   Literal value;
@@ -626,7 +627,7 @@ public:
 
 class Unary : public SpecificExpression<Expression::UnaryId> {
 public:
-  Unary() {}
+  Unary() = default;
   Unary(MixedArena& allocator) {}
 
   UnaryOp op;
@@ -639,7 +640,7 @@ public:
 
 class Binary : public SpecificExpression<Expression::BinaryId> {
 public:
-  Binary() {}
+  Binary() = default;
   Binary(MixedArena& allocator) {}
 
   BinaryOp op;
@@ -656,7 +657,7 @@ public:
 
 class Select : public SpecificExpression<Expression::SelectId> {
 public:
-  Select() {}
+  Select() = default;
   Select(MixedArena& allocator) {}
 
   Expression* ifTrue;
@@ -668,7 +669,7 @@ public:
 
 class Drop : public SpecificExpression<Expression::DropId> {
 public:
-  Drop() {}
+  Drop() = default;
   Drop(MixedArena& allocator) {}
 
   Expression* value;
@@ -678,12 +679,12 @@ public:
 
 class Return : public SpecificExpression<Expression::ReturnId> {
 public:
-  Return() : value(nullptr) {
+  Return() {
     type = unreachable;
   }
   Return(MixedArena& allocator) : Return() {}
 
-  Expression* value;
+  Expression* value = nullptr;
 };
 
 class Host : public SpecificExpression<Expression::HostId> {
@@ -808,7 +809,7 @@ public:
   struct Segment {
     Expression* offset;
     std::vector<Name> data;
-    Segment() {}
+    Segment() = default;
     Segment(Expression* offset) : offset(offset) {}
     Segment(Expression* offset, std::vector<Name>& init) : offset(offset) {
       data.swap(init);
@@ -817,12 +818,13 @@ public:
 
   // Currently the wasm object always 'has' one Table. It 'exists' if it has been defined or imported.
   // The table can exist but be empty and have no defined initial or max size.
-  bool exists;
+  bool exists = false;
   Name name;
-  Address initial, max;
+  Address initial = 0;
+  Address max = kMaxSize;
   std::vector<Segment> segments;
 
-  Table() : exists(false), initial(0), max(kMaxSize) {
+  Table() {
     name = Name::fromInt(0);
   }
   bool hasMax() { return max != kUnlimitedSize; }
@@ -839,7 +841,7 @@ public:
   struct Segment {
     Expression* offset;
     std::vector<char> data; // TODO: optimize
-    Segment() {}
+    Segment() = default;
     Segment(Expression* offset) : offset(offset) {}
     Segment(Expression* offset, const char* init, Address size) : offset(offset) {
       data.resize(size);
@@ -850,15 +852,16 @@ public:
     }
   };
 
+  bool exists = false;
   Name name;
-  Address initial, max; // sizes are in pages
+  Address initial = 0; // sizes are in pages
+  Address max = kMaxSize;
   std::vector<Segment> segments;
 
   // See comment in Table.
-  bool exists;
-  bool shared;
+  bool shared = false;
 
-  Memory() : initial(0), max(kMaxSize), exists(false), shared(false) {
+  Memory() {
     name = Name::fromInt(0);
   }
   bool hasMax() { return max != kUnlimitedSize; }
@@ -905,7 +908,7 @@ private:
   std::map<Name, Global*> globalsMap;
 
 public:
-  Module() {};
+  Module() = default;;
 
   FunctionType* getFunctionType(Name name);
   Export* getExport(Name name);
diff --git a/src/wasm/wasm-s-parser.cpp b/src/wasm/wasm-s-parser.cpp
index f5280bc33..96686cd4d 100644
--- a/src/wasm/wasm-s-parser.cpp
+++ b/src/wasm/wasm-s-parser.cpp
@@ -104,7 +104,7 @@ void Element::dump() {
 }
 
 
-SExpressionParser::SExpressionParser(char* input) : input(input), loc(nullptr) {
+SExpressionParser::SExpressionParser(char* input) : input(input) {
   root = nullptr;
   line = 1;
   lineStart = input;
@@ -253,7 +253,7 @@ Element* SExpressionParser::parseString() {
   return ret;
 }
 
-SExpressionWasmBuilder::SExpressionWasmBuilder(Module& wasm, Element& module, Name* moduleName) : wasm(wasm), allocator(wasm.allocator), globalCounter(0) {
+SExpressionWasmBuilder::SExpressionWasmBuilder(Module& wasm, Element& module, Name* moduleName) : wasm(wasm), allocator(wasm.allocator) {
   if (module.size() == 0) throw ParseException("empty toplevel, expected module");
   if (module[0]->str() != MODULE) throw ParseException("toplevel does not start with module");
   if (module.size() == 1) return;