From 6e3c348b7fb8d30d84e57e11ad056cb888bb5815 Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Wed, 30 Jan 2019 15:30:02 +0100
Subject: [PATCH 01/12] Implement calls to 'super()'

---
 src/ast.ts                              |   3 +-
 src/compiler.ts                         |  44 +++++
 src/resolver.ts                         |  10 +-
 tests/compiler/call-super.optimized.wat | 173 ++++++++++++++++++
 tests/compiler/call-super.ts            |  24 +++
 tests/compiler/call-super.untouched.wat | 232 ++++++++++++++++++++++++
 6 files changed, 484 insertions(+), 2 deletions(-)
 create mode 100644 tests/compiler/call-super.optimized.wat
 create mode 100644 tests/compiler/call-super.ts
 create mode 100644 tests/compiler/call-super.untouched.wat

diff --git a/src/ast.ts b/src/ast.ts
index 1b2a839a5c..a3290e11b5 100644
--- a/src/ast.ts
+++ b/src/ast.ts
@@ -120,7 +120,8 @@ export function nodeIsCallable(kind: NodeKind): bool {
     case NodeKind.CALL:
     case NodeKind.ELEMENTACCESS:
     case NodeKind.PARENTHESIZED:
-    case NodeKind.PROPERTYACCESS: return true;
+    case NodeKind.PROPERTYACCESS:
+    case NodeKind.SUPER: return true;
   }
   return false;
 }
diff --git a/src/compiler.ts b/src/compiler.ts
index c8d6bbd292..f6726eeb62 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -5230,6 +5230,19 @@ export class Compiler extends DiagnosticEmitter {
         break;
       }
 
+      // call to `super()`
+      case ElementKind.CLASS: {
+        if (expression.expression.kind == NodeKind.SUPER) {
+          let classInstance = assert(currentFunction.parent);
+          assert(classInstance.kind == ElementKind.CLASS);
+          let expr = this.compileSuperInstantiate(<Class>classInstance, expression.arguments, expression);
+          this.currentType = Type.void;
+          let thisLocal = assert(this.currentFunction.flow.getScopedLocal("this"));
+          return module.createSetLocal(thisLocal.index, expr);
+        }
+        // otherwise fall-through
+      }
+
       // not supported
       default: {
         this.error(
@@ -6658,6 +6671,37 @@ export class Compiler extends DiagnosticEmitter {
     return expr;
   }
 
+  compileSuperInstantiate(classInstance: Class, argumentExpressions: Expression[], reportNode: Node): ExpressionRef {
+    // traverse to the top-most visible constructor (except the current one)
+    var currentClassInstance: Class | null = classInstance.base;
+    var constructorInstance: Function | null = null;
+    while (currentClassInstance) {
+      constructorInstance = currentClassInstance.constructorInstance;
+      if (constructorInstance) break; // TODO: check visibility
+      currentClassInstance = currentClassInstance.base;
+    }
+
+    // if a constructor is present, allocate the necessary memory for `this` and call it
+    var expr: ExpressionRef;
+    if (constructorInstance) {
+      expr = this.compileCallDirect(constructorInstance, argumentExpressions, reportNode,
+        this.makeAllocate(classInstance, reportNode)
+      );
+
+    // otherwise simply allocate a new instance and initialize its fields
+    } else {
+      if (argumentExpressions.length) {
+        this.error(
+          DiagnosticCode.Expected_0_arguments_but_got_1,
+          reportNode.range, "0", argumentExpressions.length.toString(10)
+        );
+      }
+      expr = this.makeAllocate(classInstance, reportNode);
+    }
+    this.currentType = classInstance.type;
+    return expr;
+  }
+
   compileParenthesizedExpression(
     expression: ParenthesizedExpression,
     contextualType: Type
diff --git a/src/resolver.ts b/src/resolver.ts
index 33f5f883c8..e24e54fd07 100644
--- a/src/resolver.ts
+++ b/src/resolver.ts
@@ -1242,8 +1242,16 @@ export class Resolver extends DiagnosticEmitter {
 
           // Lay out fields in advance
           case ElementKind.FIELD_PROTOTYPE: {
-            if (!instance.members) instance.members = new Map();
             let fieldDeclaration = (<FieldPrototype>member).declaration;
+            if (!instance.members) instance.members = new Map();
+            else if (instance.members.has(member.simpleName)) {
+              this.error(
+                DiagnosticCode.Duplicate_identifier_0,
+                fieldDeclaration.name.range,
+                member.simpleName
+              );
+              break;
+            }
             let fieldType: Type | null = null;
             // TODO: handle duplicate non-private fields
             if (!fieldDeclaration.type) {
diff --git a/tests/compiler/call-super.optimized.wat b/tests/compiler/call-super.optimized.wat
new file mode 100644
index 0000000000..25a75bc106
--- /dev/null
+++ b/tests/compiler/call-super.optimized.wat
@@ -0,0 +1,173 @@
+(module
+ (type $v (func))
+ (type $ii (func (param i32) (result i32)))
+ (type $iiiiv (func (param i32 i32 i32 i32)))
+ (type $FUNCSIG$i (func (result i32)))
+ (import "env" "abort" (func $~lib/env/abort (param i32 i32 i32 i32)))
+ (memory $0 1)
+ (data (i32.const 8) "\0d\00\00\00c\00a\00l\00l\00-\00s\00u\00p\00e\00r\00.\00t\00s")
+ (table $0 1 anyfunc)
+ (elem (i32.const 0) $null)
+ (global $~lib/allocator/arena/startOffset (mut i32) (i32.const 0))
+ (global $~lib/allocator/arena/offset (mut i32) (i32.const 0))
+ (export "memory" (memory $0))
+ (export "table" (table $0))
+ (start $start)
+ (func $~lib/allocator/arena/__memory_allocate (; 1 ;) (type $ii) (param $0 i32) (result i32)
+  (local $1 i32)
+  (local $2 i32)
+  (local $3 i32)
+  get_local $0
+  i32.const 1073741824
+  i32.gt_u
+  if
+   unreachable
+  end
+  get_global $~lib/allocator/arena/offset
+  tee_local $1
+  get_local $0
+  i32.const 1
+  get_local $0
+  i32.const 1
+  i32.gt_u
+  select
+  i32.add
+  i32.const 7
+  i32.add
+  i32.const -8
+  i32.and
+  tee_local $2
+  current_memory
+  tee_local $3
+  i32.const 16
+  i32.shl
+  i32.gt_u
+  if
+   get_local $3
+   get_local $2
+   get_local $1
+   i32.sub
+   i32.const 65535
+   i32.add
+   i32.const -65536
+   i32.and
+   i32.const 16
+   i32.shr_u
+   tee_local $0
+   get_local $3
+   get_local $0
+   i32.gt_s
+   select
+   grow_memory
+   i32.const 0
+   i32.lt_s
+   if
+    get_local $0
+    grow_memory
+    i32.const 0
+    i32.lt_s
+    if
+     unreachable
+    end
+   end
+  end
+  get_local $2
+  set_global $~lib/allocator/arena/offset
+  get_local $1
+ )
+ (func $call-super/B#constructor (; 2 ;) (type $FUNCSIG$i) (result i32)
+  (local $0 i32)
+  i32.const 8
+  call $~lib/allocator/arena/__memory_allocate
+  tee_local $0
+  i32.const 1
+  i32.store
+  get_local $0
+  i32.const 2
+  i32.store offset=4
+  get_local $0
+  i32.eqz
+  if
+   i32.const 4
+   call $~lib/allocator/arena/__memory_allocate
+   tee_local $0
+   i32.const 1
+   i32.store
+  end
+  get_local $0
+  i32.eqz
+  if
+   i32.const 8
+   call $~lib/allocator/arena/__memory_allocate
+   tee_local $0
+   i32.const 1
+   i32.store
+   get_local $0
+   i32.const 2
+   i32.store offset=4
+  end
+  get_local $0
+  i32.load
+  i32.const 1
+  i32.ne
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 13
+   i32.const 4
+   call $~lib/env/abort
+   unreachable
+  end
+  get_local $0
+  i32.load offset=4
+  i32.const 2
+  i32.ne
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 14
+   i32.const 4
+   call $~lib/env/abort
+   unreachable
+  end
+  get_local $0
+ )
+ (func $call-super/test (; 3 ;) (type $v)
+  (local $0 i32)
+  call $call-super/B#constructor
+  tee_local $0
+  i32.load
+  i32.const 1
+  i32.ne
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 20
+   i32.const 2
+   call $~lib/env/abort
+   unreachable
+  end
+  get_local $0
+  i32.load offset=4
+  i32.const 2
+  i32.ne
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 21
+   i32.const 2
+   call $~lib/env/abort
+   unreachable
+  end
+ )
+ (func $start (; 4 ;) (type $v)
+  i32.const 40
+  set_global $~lib/allocator/arena/startOffset
+  get_global $~lib/allocator/arena/startOffset
+  set_global $~lib/allocator/arena/offset
+  call $call-super/test
+ )
+ (func $null (; 5 ;) (type $v)
+  nop
+ )
+)
diff --git a/tests/compiler/call-super.ts b/tests/compiler/call-super.ts
new file mode 100644
index 0000000000..dab4214d25
--- /dev/null
+++ b/tests/compiler/call-super.ts
@@ -0,0 +1,24 @@
+import "allocator/arena";
+
+class A {
+  a: i32 = 1;
+  constructor() {
+  }
+}
+
+class B extends A {
+  b: i32 = 2;
+  constructor() {
+    super();
+    assert(this.a == 1);
+    assert(this.b == 2);
+  }
+}
+
+function test(): void {
+  var b = new B();
+  assert(b.a == 1);
+  assert(b.b == 2);
+}
+
+test();
diff --git a/tests/compiler/call-super.untouched.wat b/tests/compiler/call-super.untouched.wat
new file mode 100644
index 0000000000..fe799c8c1b
--- /dev/null
+++ b/tests/compiler/call-super.untouched.wat
@@ -0,0 +1,232 @@
+(module
+ (type $v (func))
+ (type $ii (func (param i32) (result i32)))
+ (type $iiiiv (func (param i32 i32 i32 i32)))
+ (import "env" "abort" (func $~lib/env/abort (param i32 i32 i32 i32)))
+ (memory $0 1)
+ (data (i32.const 8) "\0d\00\00\00c\00a\00l\00l\00-\00s\00u\00p\00e\00r\00.\00t\00s\00")
+ (table $0 1 anyfunc)
+ (elem (i32.const 0) $null)
+ (global $~lib/internal/allocator/AL_BITS i32 (i32.const 3))
+ (global $~lib/internal/allocator/AL_SIZE i32 (i32.const 8))
+ (global $~lib/internal/allocator/AL_MASK i32 (i32.const 7))
+ (global $~lib/internal/allocator/MAX_SIZE_32 i32 (i32.const 1073741824))
+ (global $~lib/allocator/arena/startOffset (mut i32) (i32.const 0))
+ (global $~lib/allocator/arena/offset (mut i32) (i32.const 0))
+ (global $HEAP_BASE i32 (i32.const 40))
+ (export "memory" (memory $0))
+ (export "table" (table $0))
+ (start $start)
+ (func $~lib/allocator/arena/__memory_allocate (; 1 ;) (type $ii) (param $0 i32) (result i32)
+  (local $1 i32)
+  (local $2 i32)
+  (local $3 i32)
+  (local $4 i32)
+  (local $5 i32)
+  (local $6 i32)
+  get_local $0
+  get_global $~lib/internal/allocator/MAX_SIZE_32
+  i32.gt_u
+  if
+   unreachable
+  end
+  get_global $~lib/allocator/arena/offset
+  set_local $1
+  get_local $1
+  get_local $0
+  tee_local $2
+  i32.const 1
+  tee_local $3
+  get_local $2
+  get_local $3
+  i32.gt_u
+  select
+  i32.add
+  get_global $~lib/internal/allocator/AL_MASK
+  i32.add
+  get_global $~lib/internal/allocator/AL_MASK
+  i32.const -1
+  i32.xor
+  i32.and
+  set_local $4
+  current_memory
+  set_local $5
+  get_local $4
+  get_local $5
+  i32.const 16
+  i32.shl
+  i32.gt_u
+  if
+   get_local $4
+   get_local $1
+   i32.sub
+   i32.const 65535
+   i32.add
+   i32.const 65535
+   i32.const -1
+   i32.xor
+   i32.and
+   i32.const 16
+   i32.shr_u
+   set_local $2
+   get_local $5
+   tee_local $3
+   get_local $2
+   tee_local $6
+   get_local $3
+   get_local $6
+   i32.gt_s
+   select
+   set_local $3
+   get_local $3
+   grow_memory
+   i32.const 0
+   i32.lt_s
+   if
+    get_local $2
+    grow_memory
+    i32.const 0
+    i32.lt_s
+    if
+     unreachable
+    end
+   end
+  end
+  get_local $4
+  set_global $~lib/allocator/arena/offset
+  get_local $1
+ )
+ (func $~lib/memory/memory.allocate (; 2 ;) (type $ii) (param $0 i32) (result i32)
+  get_local $0
+  call $~lib/allocator/arena/__memory_allocate
+  return
+ )
+ (func $call-super/A#constructor (; 3 ;) (type $ii) (param $0 i32) (result i32)
+  (local $1 i32)
+  get_local $0
+  if (result i32)
+   get_local $0
+  else   
+   block (result i32)
+    i32.const 4
+    call $~lib/memory/memory.allocate
+    set_local $1
+    get_local $1
+    i32.const 1
+    i32.store
+    get_local $1
+   end
+   tee_local $0
+  end
+  tee_local $0
+ )
+ (func $call-super/B#constructor (; 4 ;) (type $ii) (param $0 i32) (result i32)
+  (local $1 i32)
+  block (result i32)
+   i32.const 8
+   call $~lib/memory/memory.allocate
+   set_local $1
+   get_local $1
+   i32.const 1
+   i32.store
+   get_local $1
+   i32.const 2
+   i32.store offset=4
+   get_local $1
+  end
+  call $call-super/A#constructor
+  set_local $0
+  get_local $0
+  if (result i32)
+   get_local $0
+  else   
+   block (result i32)
+    i32.const 8
+    call $~lib/memory/memory.allocate
+    set_local $1
+    get_local $1
+    i32.const 1
+    i32.store
+    get_local $1
+    i32.const 2
+    i32.store offset=4
+    get_local $1
+   end
+   tee_local $0
+  end
+  tee_local $0
+  i32.load
+  i32.const 1
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 13
+   i32.const 4
+   call $~lib/env/abort
+   unreachable
+  end
+  get_local $0
+  i32.load offset=4
+  i32.const 2
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 14
+   i32.const 4
+   call $~lib/env/abort
+   unreachable
+  end
+  get_local $0
+ )
+ (func $call-super/test (; 5 ;) (type $v)
+  (local $0 i32)
+  i32.const 0
+  call $call-super/B#constructor
+  set_local $0
+  get_local $0
+  i32.load
+  i32.const 1
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 20
+   i32.const 2
+   call $~lib/env/abort
+   unreachable
+  end
+  get_local $0
+  i32.load offset=4
+  i32.const 2
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 21
+   i32.const 2
+   call $~lib/env/abort
+   unreachable
+  end
+ )
+ (func $start (; 6 ;) (type $v)
+  get_global $HEAP_BASE
+  get_global $~lib/internal/allocator/AL_MASK
+  i32.add
+  get_global $~lib/internal/allocator/AL_MASK
+  i32.const -1
+  i32.xor
+  i32.and
+  set_global $~lib/allocator/arena/startOffset
+  get_global $~lib/allocator/arena/startOffset
+  set_global $~lib/allocator/arena/offset
+  call $call-super/test
+ )
+ (func $null (; 7 ;) (type $v)
+ )
+)

From a749af919b14cc70623bf9000833f7e6d5edffa7 Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Wed, 30 Jan 2019 17:45:01 +0100
Subject: [PATCH 02/12] check that super() is the first statement in
 constructors of derived classes

---
 src/ast.ts                          |  6 ++++++
 src/compiler.ts                     | 14 +++++++++++++-
 src/diagnosticMessages.generated.ts |  2 ++
 src/diagnosticMessages.json         |  1 +
 4 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/ast.ts b/src/ast.ts
index a3290e11b5..7b57aa90f1 100644
--- a/src/ast.ts
+++ b/src/ast.ts
@@ -135,6 +135,12 @@ export function nodeIsGenericCallable(kind: NodeKind): bool {
   return false;
 }
 
+export function nodeIsSuperCall(node: Node): bool {
+  if (node.kind == NodeKind.EXPRESSION) node = (<ExpressionStatement>node).expression;
+  return node.kind == NodeKind.CALL
+      && (<CallExpression>node).expression.kind == NodeKind.SUPER;
+}
+
 /** Base class of all nodes. */
 export abstract class Node {
 
diff --git a/src/compiler.ts b/src/compiler.ts
index f6726eeb62..56cf6ba229 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -144,6 +144,7 @@ import {
   FieldDeclaration,
 
   nodeIsConstantValue,
+  nodeIsSuperCall,
   isLastStatement,
   findDecorator
 } from "./ast";
@@ -1075,7 +1076,18 @@ export class Compiler extends DiagnosticEmitter {
         flow.finalize();
       } else {
         assert(body.kind == NodeKind.BLOCK);
-        let stmts = this.compileStatements((<BlockStatement>body).statements);
+        let statements = (<BlockStatement>body).statements;
+        if (isConstructor) { // make sure super() is called first if this is a derived class
+          let parent = assert(instance.parent);
+          assert(parent.kind == ElementKind.CLASS);
+          if ((<Class>parent).base && !(statements.length >= 1 && nodeIsSuperCall(statements[0]))) {
+            this.error(
+              DiagnosticCode.Constructors_for_derived_classes_must_call_super_first,
+              statements[0].range.atStart
+            );
+          }
+        }
+        let stmts = this.compileStatements(statements);
         if (instance.is(CommonFlags.MAIN)) {
           module.addGlobal("~started", NativeType.I32, true, module.createI32(0));
           stmts.unshift(
diff --git a/src/diagnosticMessages.generated.ts b/src/diagnosticMessages.generated.ts
index 85c5b678f5..75b9822bc1 100644
--- a/src/diagnosticMessages.generated.ts
+++ b/src/diagnosticMessages.generated.ts
@@ -101,6 +101,7 @@ export enum DiagnosticCode {
   The_operand_of_an_increment_or_decrement_operator_must_be_a_variable_or_a_property_access = 2357,
   The_left_hand_side_of_an_assignment_expression_must_be_a_variable_or_a_property_access = 2364,
   Operator_0_cannot_be_applied_to_types_1_and_2 = 2365,
+  Constructors_for_derived_classes_must_call_super_first = 2377,
   _get_and_set_accessor_must_have_the_same_type = 2380,
   Constructor_implementation_is_missing = 2390,
   Function_implementation_is_missing_or_not_immediately_following_the_declaration = 2391,
@@ -224,6 +225,7 @@ export function diagnosticCodeToString(code: DiagnosticCode): string {
     case 2357: return "The operand of an increment or decrement operator must be a variable or a property access.";
     case 2364: return "The left-hand side of an assignment expression must be a variable or a property access.";
     case 2365: return "Operator '{0}' cannot be applied to types '{1}' and '{2}'.";
+    case 2377: return "Constructors for derived classes must call 'super' first.";
     case 2380: return "'get' and 'set' accessor must have the same type.";
     case 2390: return "Constructor implementation is missing.";
     case 2391: return "Function implementation is missing or not immediately following the declaration.";
diff --git a/src/diagnosticMessages.json b/src/diagnosticMessages.json
index 3594958b40..4aa25dc04f 100644
--- a/src/diagnosticMessages.json
+++ b/src/diagnosticMessages.json
@@ -95,6 +95,7 @@
   "The operand of an increment or decrement operator must be a variable or a property access.": 2357,
   "The left-hand side of an assignment expression must be a variable or a property access.": 2364,
   "Operator '{0}' cannot be applied to types '{1}' and '{2}'.": 2365,
+  "Constructors for derived classes must call 'super' first.": 2377,
   "'get' and 'set' accessor must have the same type.": 2380,
   "Constructor implementation is missing.": 2390,
   "Function implementation is missing or not immediately following the declaration.": 2391,

From 92ac40616f6635024c568f1467c1df5fc58fdeb2 Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Wed, 30 Jan 2019 18:14:47 +0100
Subject: [PATCH 03/12] also check that super calls are the first statement
 within their constructor when compiling them

---
 src/ast.ts                          | 8 ++++++++
 src/compiler.ts                     | 9 ++++++++-
 src/diagnosticMessages.generated.ts | 2 ++
 src/diagnosticMessages.json         | 1 +
 4 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/ast.ts b/src/ast.ts
index 7b57aa90f1..94e6aa6fbf 100644
--- a/src/ast.ts
+++ b/src/ast.ts
@@ -1824,6 +1824,14 @@ export class FunctionDeclaration extends DeclarationStatement {
     var typeParameters = this.typeParameters;
     return typeParameters != null && typeParameters.length > 0;
   }
+
+  get firstStatement(): Statement | null {
+    var body = this.body;
+    if (!(body && body.kind == NodeKind.BLOCK)) return null;
+    var statements = (<BlockStatement>body).statements;
+    if (statements.length < 0) return null;
+    return statements[0];
+  }
 }
 
 /** Represents an `if` statement. */
diff --git a/src/compiler.ts b/src/compiler.ts
index 56cf6ba229..252a2160b0 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -5244,7 +5244,14 @@ export class Compiler extends DiagnosticEmitter {
 
       // call to `super()`
       case ElementKind.CLASS: {
-        if (expression.expression.kind == NodeKind.SUPER) {
+        if (expression.expression.kind == NodeKind.SUPER && currentFunction.is(CommonFlags.CONSTRUCTOR)) {
+          if (expression.parent != currentFunction.prototype.declaration.firstStatement) {
+            this.error(
+              DiagnosticCode.A_super_call_must_be_the_first_statement_in_the_constructor,
+              expression.range
+            );
+            return module.createUnreachable();
+          }
           let classInstance = assert(currentFunction.parent);
           assert(classInstance.kind == ElementKind.CLASS);
           let expr = this.compileSuperInstantiate(<Class>classInstance, expression.arguments, expression);
diff --git a/src/diagnosticMessages.generated.ts b/src/diagnosticMessages.generated.ts
index 75b9822bc1..c769c38dfe 100644
--- a/src/diagnosticMessages.generated.ts
+++ b/src/diagnosticMessages.generated.ts
@@ -101,6 +101,7 @@ export enum DiagnosticCode {
   The_operand_of_an_increment_or_decrement_operator_must_be_a_variable_or_a_property_access = 2357,
   The_left_hand_side_of_an_assignment_expression_must_be_a_variable_or_a_property_access = 2364,
   Operator_0_cannot_be_applied_to_types_1_and_2 = 2365,
+  A_super_call_must_be_the_first_statement_in_the_constructor = 2376,
   Constructors_for_derived_classes_must_call_super_first = 2377,
   _get_and_set_accessor_must_have_the_same_type = 2380,
   Constructor_implementation_is_missing = 2390,
@@ -225,6 +226,7 @@ export function diagnosticCodeToString(code: DiagnosticCode): string {
     case 2357: return "The operand of an increment or decrement operator must be a variable or a property access.";
     case 2364: return "The left-hand side of an assignment expression must be a variable or a property access.";
     case 2365: return "Operator '{0}' cannot be applied to types '{1}' and '{2}'.";
+    case 2376: return "A 'super' call must be the first statement in the constructor.";
     case 2377: return "Constructors for derived classes must call 'super' first.";
     case 2380: return "'get' and 'set' accessor must have the same type.";
     case 2390: return "Constructor implementation is missing.";
diff --git a/src/diagnosticMessages.json b/src/diagnosticMessages.json
index 4aa25dc04f..bcd801c98f 100644
--- a/src/diagnosticMessages.json
+++ b/src/diagnosticMessages.json
@@ -95,6 +95,7 @@
   "The operand of an increment or decrement operator must be a variable or a property access.": 2357,
   "The left-hand side of an assignment expression must be a variable or a property access.": 2364,
   "Operator '{0}' cannot be applied to types '{1}' and '{2}'.": 2365,
+  "A 'super' call must be the first statement in the constructor.": 2376,
   "Constructors for derived classes must call 'super' first.": 2377,
   "'get' and 'set' accessor must have the same type.": 2380,
   "Constructor implementation is missing.": 2390,

From c5fc6c63ac8016101d4438f0eee0fbb040734d4a Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Wed, 30 Jan 2019 18:17:15 +0100
Subject: [PATCH 04/12] fix

---
 src/ast.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/ast.ts b/src/ast.ts
index 94e6aa6fbf..cf2bd6bd37 100644
--- a/src/ast.ts
+++ b/src/ast.ts
@@ -1829,7 +1829,7 @@ export class FunctionDeclaration extends DeclarationStatement {
     var body = this.body;
     if (!(body && body.kind == NodeKind.BLOCK)) return null;
     var statements = (<BlockStatement>body).statements;
-    if (statements.length < 0) return null;
+    if (!statements.length) return null;
     return statements[0];
   }
 }

From 8b065bfd484febbc6eb9d8709103529d92b87f2f Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Wed, 30 Jan 2019 18:33:55 +0100
Subject: [PATCH 05/12] add diagnostic for when trying to call super outside of
 a ctor

---
 src/compiler.ts                     | 12 ++++++++++--
 src/diagnosticMessages.generated.ts |  2 ++
 src/diagnosticMessages.json         |  1 +
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/compiler.ts b/src/compiler.ts
index 252a2160b0..7336cbf682 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -5242,9 +5242,17 @@ export class Compiler extends DiagnosticEmitter {
         break;
       }
 
-      // call to `super()`
       case ElementKind.CLASS: {
-        if (expression.expression.kind == NodeKind.SUPER && currentFunction.is(CommonFlags.CONSTRUCTOR)) {
+
+        // call to `super()`
+        if (expression.expression.kind == NodeKind.SUPER) {
+          if (!currentFunction.is(CommonFlags.CONSTRUCTOR)) {
+            this.error(
+              DiagnosticCode.Super_calls_are_not_permitted_outside_constructors_or_in_nested_functions_inside_constructors,
+              expression.range
+            );
+            return module.createUnreachable();
+          }
           if (expression.parent != currentFunction.prototype.declaration.firstStatement) {
             this.error(
               DiagnosticCode.A_super_call_must_be_the_first_statement_in_the_constructor,
diff --git a/src/diagnosticMessages.generated.ts b/src/diagnosticMessages.generated.ts
index c769c38dfe..6cbb34d373 100644
--- a/src/diagnosticMessages.generated.ts
+++ b/src/diagnosticMessages.generated.ts
@@ -94,6 +94,7 @@ export enum DiagnosticCode {
   Index_signature_is_missing_in_type_0 = 2329,
   _this_cannot_be_referenced_in_current_location = 2332,
   _super_can_only_be_referenced_in_a_derived_class = 2335,
+  Super_calls_are_not_permitted_outside_constructors_or_in_nested_functions_inside_constructors = 2337,
   Property_0_does_not_exist_on_type_1 = 2339,
   Cannot_invoke_an_expression_whose_type_lacks_a_call_signature_Type_0_has_no_compatible_call_signatures = 2349,
   Cannot_use_new_with_an_expression_whose_type_lacks_a_construct_signature = 2351,
@@ -219,6 +220,7 @@ export function diagnosticCodeToString(code: DiagnosticCode): string {
     case 2329: return "Index signature is missing in type '{0}'.";
     case 2332: return "'this' cannot be referenced in current location.";
     case 2335: return "'super' can only be referenced in a derived class.";
+    case 2337: return "Super calls are not permitted outside constructors or in nested functions inside constructors.";
     case 2339: return "Property '{0}' does not exist on type '{1}'.";
     case 2349: return "Cannot invoke an expression whose type lacks a call signature. Type '{0}' has no compatible call signatures.";
     case 2351: return "Cannot use 'new' with an expression whose type lacks a construct signature.";
diff --git a/src/diagnosticMessages.json b/src/diagnosticMessages.json
index bcd801c98f..24bc5677ff 100644
--- a/src/diagnosticMessages.json
+++ b/src/diagnosticMessages.json
@@ -88,6 +88,7 @@
   "Index signature is missing in type '{0}'.": 2329,
   "'this' cannot be referenced in current location.": 2332,
   "'super' can only be referenced in a derived class.": 2335,
+  "Super calls are not permitted outside constructors or in nested functions inside constructors.": 2337,
   "Property '{0}' does not exist on type '{1}'.": 2339,
   "Cannot invoke an expression whose type lacks a call signature. Type '{0}' has no compatible call signatures.": 2349,
   "Cannot use 'new' with an expression whose type lacks a construct signature.": 2351,

From 891d654ed8cab2b3cbbee7bf87872d87e5c6e7f8 Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Wed, 30 Jan 2019 19:17:57 +0100
Subject: [PATCH 06/12] utilize flow to check for super conditions

---
 src/compiler.ts                         | 43 ++++++++++++++-----------
 src/diagnosticMessages.generated.ts     |  8 +++--
 src/diagnosticMessages.json             |  5 +--
 src/program.ts                          | 16 +++++----
 tests/compiler/call-super.optimized.wat | 12 -------
 tests/compiler/call-super.untouched.wat | 18 -----------
 6 files changed, 42 insertions(+), 60 deletions(-)

diff --git a/src/compiler.ts b/src/compiler.ts
index 7336cbf682..e8ace960a5 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -1077,16 +1077,6 @@ export class Compiler extends DiagnosticEmitter {
       } else {
         assert(body.kind == NodeKind.BLOCK);
         let statements = (<BlockStatement>body).statements;
-        if (isConstructor) { // make sure super() is called first if this is a derived class
-          let parent = assert(instance.parent);
-          assert(parent.kind == ElementKind.CLASS);
-          if ((<Class>parent).base && !(statements.length >= 1 && nodeIsSuperCall(statements[0]))) {
-            this.error(
-              DiagnosticCode.Constructors_for_derived_classes_must_call_super_first,
-              statements[0].range.atStart
-            );
-          }
-        }
         let stmts = this.compileStatements(statements);
         if (instance.is(CommonFlags.MAIN)) {
           module.addGlobal("~started", NativeType.I32, true, module.createI32(0));
@@ -1107,6 +1097,8 @@ export class Compiler extends DiagnosticEmitter {
         if (isConstructor) {
           let nativeSizeType = this.options.nativeSizeType;
           assert(instance.is(CommonFlags.INSTANCE));
+          let parent = assert(instance.parent);
+          assert(parent.kind == ElementKind.CLASS);
 
           // implicitly return `this` if the constructor doesn't always return on its own
           if (!flow.is(FlowFlags.RETURNS)) {
@@ -1117,14 +1109,20 @@ export class Compiler extends DiagnosticEmitter {
 
             // if not all branches are guaranteed to allocate, also append a conditional allocation
             } else {
-              let parent = assert(instance.parent);
-              assert(parent.kind == ElementKind.CLASS);
               stmts.push(module.createTeeLocal(0,
                 this.makeConditionalAllocate(<Class>parent, declaration.name)
               ));
             }
           }
 
+          // check that super has been called if this is a derived class
+          if ((<Class>parent).base && !flow.is(FlowFlags.CALLS_SUPER)) {
+            this.error(
+              DiagnosticCode.Constructors_for_derived_classes_must_contain_a_super_call,
+              instance.prototype.declaration.range
+            );
+          }
+
         // make sure all branches return
         } else if (returnType != Type.void && !flow.is(FlowFlags.RETURNS)) {
           this.error(
@@ -5253,17 +5251,26 @@ export class Compiler extends DiagnosticEmitter {
             );
             return module.createUnreachable();
           }
-          if (expression.parent != currentFunction.prototype.declaration.firstStatement) {
+
+          let classInstance = assert(currentFunction.parent);
+          assert(classInstance.kind == ElementKind.CLASS);
+          let expr = this.compileSuperInstantiate(<Class>classInstance, expression.arguments, expression);
+          this.currentType = Type.void;
+
+          // check that super() is called before allocation is performed (incl. in super arguments)
+          let flow = currentFunction.flow;
+          if (flow.isAny(
+            FlowFlags.ALLOCATES |
+            FlowFlags.CONDITIONALLY_ALLOCATES
+          )) {
             this.error(
-              DiagnosticCode.A_super_call_must_be_the_first_statement_in_the_constructor,
+              DiagnosticCode._super_must_be_called_before_accessing_this_in_the_constructor_of_a_derived_class,
               expression.range
             );
             return module.createUnreachable();
           }
-          let classInstance = assert(currentFunction.parent);
-          assert(classInstance.kind == ElementKind.CLASS);
-          let expr = this.compileSuperInstantiate(<Class>classInstance, expression.arguments, expression);
-          this.currentType = Type.void;
+          flow.set(FlowFlags.ALLOCATES | FlowFlags.CALLS_SUPER);
+
           let thisLocal = assert(this.currentFunction.flow.getScopedLocal("this"));
           return module.createSetLocal(thisLocal.index, expr);
         }
diff --git a/src/diagnosticMessages.generated.ts b/src/diagnosticMessages.generated.ts
index 6cbb34d373..4c76e59bf5 100644
--- a/src/diagnosticMessages.generated.ts
+++ b/src/diagnosticMessages.generated.ts
@@ -103,7 +103,7 @@ export enum DiagnosticCode {
   The_left_hand_side_of_an_assignment_expression_must_be_a_variable_or_a_property_access = 2364,
   Operator_0_cannot_be_applied_to_types_1_and_2 = 2365,
   A_super_call_must_be_the_first_statement_in_the_constructor = 2376,
-  Constructors_for_derived_classes_must_call_super_first = 2377,
+  Constructors_for_derived_classes_must_contain_a_super_call = 2377,
   _get_and_set_accessor_must_have_the_same_type = 2380,
   Constructor_implementation_is_missing = 2390,
   Function_implementation_is_missing_or_not_immediately_following_the_declaration = 2391,
@@ -127,7 +127,8 @@ export enum DiagnosticCode {
   Required_type_parameters_may_not_follow_optional_type_parameters = 2706,
   File_0_not_found = 6054,
   Numeric_separators_are_not_allowed_here = 6188,
-  Multiple_consecutive_numeric_separators_are_not_permitted = 6189
+  Multiple_consecutive_numeric_separators_are_not_permitted = 6189,
+  _super_must_be_called_before_accessing_this_in_the_constructor_of_a_derived_class = 17009
 }
 
 /** Translates a diagnostic code to its respective string. */
@@ -229,7 +230,7 @@ export function diagnosticCodeToString(code: DiagnosticCode): string {
     case 2364: return "The left-hand side of an assignment expression must be a variable or a property access.";
     case 2365: return "Operator '{0}' cannot be applied to types '{1}' and '{2}'.";
     case 2376: return "A 'super' call must be the first statement in the constructor.";
-    case 2377: return "Constructors for derived classes must call 'super' first.";
+    case 2377: return "Constructors for derived classes must contain a 'super' call.";
     case 2380: return "'get' and 'set' accessor must have the same type.";
     case 2390: return "Constructor implementation is missing.";
     case 2391: return "Function implementation is missing or not immediately following the declaration.";
@@ -254,6 +255,7 @@ export function diagnosticCodeToString(code: DiagnosticCode): string {
     case 6054: return "File '{0}' not found.";
     case 6188: return "Numeric separators are not allowed here.";
     case 6189: return "Multiple consecutive numeric separators are not permitted.";
+    case 17009: return "'super' must be called before accessing 'this' in the constructor of a derived class.";
     default: return "";
   }
 }
diff --git a/src/diagnosticMessages.json b/src/diagnosticMessages.json
index 24bc5677ff..85006c6824 100644
--- a/src/diagnosticMessages.json
+++ b/src/diagnosticMessages.json
@@ -97,7 +97,7 @@
   "The left-hand side of an assignment expression must be a variable or a property access.": 2364,
   "Operator '{0}' cannot be applied to types '{1}' and '{2}'.": 2365,
   "A 'super' call must be the first statement in the constructor.": 2376,
-  "Constructors for derived classes must call 'super' first.": 2377,
+  "Constructors for derived classes must contain a 'super' call.": 2377,
   "'get' and 'set' accessor must have the same type.": 2380,
   "Constructor implementation is missing.": 2390,
   "Function implementation is missing or not immediately following the declaration.": 2391,
@@ -122,5 +122,6 @@
 
   "File '{0}' not found.": 6054,
   "Numeric separators are not allowed here.": 6188,
-  "Multiple consecutive numeric separators are not permitted.": 6189
+  "Multiple consecutive numeric separators are not permitted.": 6189,
+  "'super' must be called before accessing 'this' in the constructor of a derived class.": 17009
 }
diff --git a/src/program.ts b/src/program.ts
index c916acf2a6..eda4f2cf40 100644
--- a/src/program.ts
+++ b/src/program.ts
@@ -3041,26 +3041,28 @@ export const enum FlowFlags {
   CONTINUES = 1 << 4,
   /** This branch always allocates. Constructors only. */
   ALLOCATES = 1 << 5,
+  /** This branch always calls super. Constructors only. */
+  CALLS_SUPER = 1 << 6,
 
   // conditional
 
   /** This branch conditionally returns in a child branch. */
-  CONDITIONALLY_RETURNS = 1 << 6,
+  CONDITIONALLY_RETURNS = 1 << 7,
   /** This branch conditionally throws in a child branch. */
-  CONDITIONALLY_THROWS = 1 << 7,
+  CONDITIONALLY_THROWS = 1 << 8,
   /** This branch conditionally breaks in a child branch. */
-  CONDITIONALLY_BREAKS = 1 << 8,
+  CONDITIONALLY_BREAKS = 1 << 9,
   /** This branch conditionally continues in a child branch. */
-  CONDITIONALLY_CONTINUES = 1 << 9,
+  CONDITIONALLY_CONTINUES = 1 << 10,
   /** This branch conditionally allocates in a child branch. Constructors only. */
-  CONDITIONALLY_ALLOCATES = 1 << 10,
+  CONDITIONALLY_ALLOCATES = 1 << 11,
 
   // special
 
   /** This branch is part of inlining a function. */
-  INLINE_CONTEXT = 1 << 11,
+  INLINE_CONTEXT = 1 << 12,
   /** This branch explicitly requests no bounds checking. */
-  UNCHECKED_CONTEXT = 1 << 12,
+  UNCHECKED_CONTEXT = 1 << 13,
 
   // masks
 
diff --git a/tests/compiler/call-super.optimized.wat b/tests/compiler/call-super.optimized.wat
index 25a75bc106..61c9388357 100644
--- a/tests/compiler/call-super.optimized.wat
+++ b/tests/compiler/call-super.optimized.wat
@@ -95,18 +95,6 @@
    i32.store
   end
   get_local $0
-  i32.eqz
-  if
-   i32.const 8
-   call $~lib/allocator/arena/__memory_allocate
-   tee_local $0
-   i32.const 1
-   i32.store
-   get_local $0
-   i32.const 2
-   i32.store offset=4
-  end
-  get_local $0
   i32.load
   i32.const 1
   i32.ne
diff --git a/tests/compiler/call-super.untouched.wat b/tests/compiler/call-super.untouched.wat
index fe799c8c1b..7e1fb52d89 100644
--- a/tests/compiler/call-super.untouched.wat
+++ b/tests/compiler/call-super.untouched.wat
@@ -137,24 +137,6 @@
   call $call-super/A#constructor
   set_local $0
   get_local $0
-  if (result i32)
-   get_local $0
-  else   
-   block (result i32)
-    i32.const 8
-    call $~lib/memory/memory.allocate
-    set_local $1
-    get_local $1
-    i32.const 1
-    i32.store
-    get_local $1
-    i32.const 2
-    i32.store offset=4
-    get_local $1
-   end
-   tee_local $0
-  end
-  tee_local $0
   i32.load
   i32.const 1
   i32.eq

From 2af8c229db71263f16e3b8d77a7c7f32ef178252 Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Wed, 30 Jan 2019 19:19:31 +0100
Subject: [PATCH 07/12] fix

---
 src/program.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/program.ts b/src/program.ts
index eda4f2cf40..f021900843 100644
--- a/src/program.ts
+++ b/src/program.ts
@@ -3078,7 +3078,8 @@ export const enum FlowFlags {
                   | FlowFlags.THROWS
                   | FlowFlags.BREAKS
                   | FlowFlags.CONTINUES
-                  | FlowFlags.ALLOCATES,
+                  | FlowFlags.ALLOCATES
+                  | FlowFlags.CALLS_SUPER,
 
   /** Any conditional flag. */
   ANY_CONDITIONAL = FlowFlags.CONDITIONALLY_RETURNS

From 50f2d6af543d82a84f845aacf74c03768af560e5 Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Wed, 30 Jan 2019 19:32:47 +0100
Subject: [PATCH 08/12] check that super has been called before accessing it
 otherwise

---
 src/ast.ts                          | 8 --------
 src/compiler.ts                     | 8 ++++++++
 src/diagnosticMessages.generated.ts | 4 +++-
 src/diagnosticMessages.json         | 3 ++-
 4 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/src/ast.ts b/src/ast.ts
index cf2bd6bd37..7b57aa90f1 100644
--- a/src/ast.ts
+++ b/src/ast.ts
@@ -1824,14 +1824,6 @@ export class FunctionDeclaration extends DeclarationStatement {
     var typeParameters = this.typeParameters;
     return typeParameters != null && typeParameters.length > 0;
   }
-
-  get firstStatement(): Statement | null {
-    var body = this.body;
-    if (!(body && body.kind == NodeKind.BLOCK)) return null;
-    var statements = (<BlockStatement>body).statements;
-    if (!statements.length) return null;
-    return statements[0];
-  }
 }
 
 /** Represents an `if` statement. */
diff --git a/src/compiler.ts b/src/compiler.ts
index e8ace960a5..0a110a8dcb 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -6074,6 +6074,14 @@ export class Compiler extends DiagnosticEmitter {
         return module.createUnreachable();
       }
       case NodeKind.SUPER: {
+        if (currentFunction.is(CommonFlags.CONSTRUCTOR)) {
+          if (!currentFunction.flow.is(FlowFlags.CALLS_SUPER)) {
+            this.error(
+              DiagnosticCode._super_must_be_called_before_accessing_a_property_of_super_in_the_constructor_of_a_derived_class,
+              expression.range
+            );
+          }
+        }
         let flow = currentFunction.flow;
         if (flow.is(FlowFlags.INLINE_CONTEXT)) {
           let scopedThis = flow.getScopedLocal("this");
diff --git a/src/diagnosticMessages.generated.ts b/src/diagnosticMessages.generated.ts
index 4c76e59bf5..1ef62a1822 100644
--- a/src/diagnosticMessages.generated.ts
+++ b/src/diagnosticMessages.generated.ts
@@ -128,7 +128,8 @@ export enum DiagnosticCode {
   File_0_not_found = 6054,
   Numeric_separators_are_not_allowed_here = 6188,
   Multiple_consecutive_numeric_separators_are_not_permitted = 6189,
-  _super_must_be_called_before_accessing_this_in_the_constructor_of_a_derived_class = 17009
+  _super_must_be_called_before_accessing_this_in_the_constructor_of_a_derived_class = 17009,
+  _super_must_be_called_before_accessing_a_property_of_super_in_the_constructor_of_a_derived_class = 17011
 }
 
 /** Translates a diagnostic code to its respective string. */
@@ -256,6 +257,7 @@ export function diagnosticCodeToString(code: DiagnosticCode): string {
     case 6188: return "Numeric separators are not allowed here.";
     case 6189: return "Multiple consecutive numeric separators are not permitted.";
     case 17009: return "'super' must be called before accessing 'this' in the constructor of a derived class.";
+    case 17011: return "'super' must be called before accessing a property of 'super' in the constructor of a derived class.";
     default: return "";
   }
 }
diff --git a/src/diagnosticMessages.json b/src/diagnosticMessages.json
index 85006c6824..9e3d82a5ba 100644
--- a/src/diagnosticMessages.json
+++ b/src/diagnosticMessages.json
@@ -123,5 +123,6 @@
   "File '{0}' not found.": 6054,
   "Numeric separators are not allowed here.": 6188,
   "Multiple consecutive numeric separators are not permitted.": 6189,
-  "'super' must be called before accessing 'this' in the constructor of a derived class.": 17009
+  "'super' must be called before accessing 'this' in the constructor of a derived class.": 17009,
+  "'super' must be called before accessing a property of 'super' in the constructor of a derived class.": 17011
 }

From f2f03fc5373b14764ab3f991e7dbdf107b757b39 Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Wed, 30 Jan 2019 19:38:35 +0100
Subject: [PATCH 09/12] validate super syntax in parser

---
 src/compiler.ts                     | 1 +
 src/diagnosticMessages.generated.ts | 2 ++
 src/diagnosticMessages.json         | 1 +
 src/parser.ts                       | 6 ++++++
 4 files changed, 10 insertions(+)

diff --git a/src/compiler.ts b/src/compiler.ts
index 0a110a8dcb..2802c5383a 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -6076,6 +6076,7 @@ export class Compiler extends DiagnosticEmitter {
       case NodeKind.SUPER: {
         if (currentFunction.is(CommonFlags.CONSTRUCTOR)) {
           if (!currentFunction.flow.is(FlowFlags.CALLS_SUPER)) {
+            // TS1034 in the parser effectively limits this to property accesses
             this.error(
               DiagnosticCode._super_must_be_called_before_accessing_a_property_of_super_in_the_constructor_of_a_derived_class,
               expression.range
diff --git a/src/diagnosticMessages.generated.ts b/src/diagnosticMessages.generated.ts
index 1ef62a1822..831dc9a4ea 100644
--- a/src/diagnosticMessages.generated.ts
+++ b/src/diagnosticMessages.generated.ts
@@ -66,6 +66,7 @@ export enum DiagnosticCode {
   Unexpected_end_of_text = 1126,
   Invalid_character = 1127,
   _case_or_default_expected = 1130,
+  _super_must_be_followed_by_an_argument_list_or_member_access = 1034,
   A_declare_modifier_cannot_be_used_in_an_already_ambient_context = 1038,
   Type_argument_expected = 1140,
   String_literal_expected = 1141,
@@ -194,6 +195,7 @@ export function diagnosticCodeToString(code: DiagnosticCode): string {
     case 1126: return "Unexpected end of text.";
     case 1127: return "Invalid character.";
     case 1130: return "'case' or 'default' expected.";
+    case 1034: return "'super' must be followed by an argument list or member access.";
     case 1038: return "A 'declare' modifier cannot be used in an already ambient context.";
     case 1140: return "Type argument expected.";
     case 1141: return "String literal expected.";
diff --git a/src/diagnosticMessages.json b/src/diagnosticMessages.json
index 9e3d82a5ba..c1830de6d8 100644
--- a/src/diagnosticMessages.json
+++ b/src/diagnosticMessages.json
@@ -59,6 +59,7 @@
   "Unexpected end of text.": 1126,
   "Invalid character.": 1127,
   "'case' or 'default' expected.": 1130,
+  "'super' must be followed by an argument list or member access.": 1034,
   "A 'declare' modifier cannot be used in an already ambient context.": 1038,
   "Type argument expected.": 1140,
   "String literal expected.": 1141,
diff --git a/src/parser.ts b/src/parser.ts
index e19cf38a80..75b24ded2d 100644
--- a/src/parser.ts
+++ b/src/parser.ts
@@ -3337,6 +3337,12 @@ export class Parser extends DiagnosticEmitter {
         return Node.createConstructorExpression(tn.range(startPos, tn.pos));
       }
       case Token.SUPER: {
+        if (tn.peek() != Token.DOT && tn.nextToken != Token.OPENPAREN) {
+          this.error(
+            DiagnosticCode._super_must_be_followed_by_an_argument_list_or_member_access,
+            tn.range()
+          );
+        }
         return Node.createSuperExpression(tn.range(startPos, tn.pos));
       }
       case Token.STRINGLITERAL: {

From 94fbbc7ede4ac840db1d1e98ab7e42b4b0092fdf Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Wed, 30 Jan 2019 20:19:24 +0100
Subject: [PATCH 10/12] minor cleanup

---
 src/ast.ts      |  6 ------
 src/compiler.ts |  4 +---
 src/program.ts  | 15 +++++++++++++++
 3 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/src/ast.ts b/src/ast.ts
index 7b57aa90f1..a3290e11b5 100644
--- a/src/ast.ts
+++ b/src/ast.ts
@@ -135,12 +135,6 @@ export function nodeIsGenericCallable(kind: NodeKind): bool {
   return false;
 }
 
-export function nodeIsSuperCall(node: Node): bool {
-  if (node.kind == NodeKind.EXPRESSION) node = (<ExpressionStatement>node).expression;
-  return node.kind == NodeKind.CALL
-      && (<CallExpression>node).expression.kind == NodeKind.SUPER;
-}
-
 /** Base class of all nodes. */
 export abstract class Node {
 
diff --git a/src/compiler.ts b/src/compiler.ts
index 2802c5383a..0723c31ade 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -144,7 +144,6 @@ import {
   FieldDeclaration,
 
   nodeIsConstantValue,
-  nodeIsSuperCall,
   isLastStatement,
   findDecorator
 } from "./ast";
@@ -1076,8 +1075,7 @@ export class Compiler extends DiagnosticEmitter {
         flow.finalize();
       } else {
         assert(body.kind == NodeKind.BLOCK);
-        let statements = (<BlockStatement>body).statements;
-        let stmts = this.compileStatements(statements);
+        let stmts = this.compileStatements((<BlockStatement>body).statements);
         if (instance.is(CommonFlags.MAIN)) {
           module.addGlobal("~started", NativeType.I32, true, module.createI32(0));
           stmts.unshift(
diff --git a/src/program.ts b/src/program.ts
index f021900843..54ff52923e 100644
--- a/src/program.ts
+++ b/src/program.ts
@@ -2931,6 +2931,21 @@ export class Class extends Element {
     }
   }
 
+  /** Gets the first applicable constructor. */
+  getfirstConstructor(includingThis: bool = true): Function | null {
+    if (includingThis && this.constructorInstance) return this.constructorInstance;
+
+    // traverse to the top-most derived constructor
+    var currentBase: Class | null = this.base;
+    var instance: Function | null = null;
+    while (currentBase) {
+      instance = currentBase.constructorInstance;
+      if (instance) return instance;
+      currentBase = currentBase.base;
+    }
+    return null;
+  }
+
   /** Tests if a value of this class type is assignable to a target of the specified class type. */
   isAssignableTo(target: Class): bool {
     var current: Class | null = this;

From ef573508ce499b6c3c2fd241502544eee884eb21 Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Thu, 31 Jan 2019 07:26:17 +0100
Subject: [PATCH 11/12] remove tinkering

---
 src/program.ts | 15 ---------------
 1 file changed, 15 deletions(-)

diff --git a/src/program.ts b/src/program.ts
index 54ff52923e..f021900843 100644
--- a/src/program.ts
+++ b/src/program.ts
@@ -2931,21 +2931,6 @@ export class Class extends Element {
     }
   }
 
-  /** Gets the first applicable constructor. */
-  getfirstConstructor(includingThis: bool = true): Function | null {
-    if (includingThis && this.constructorInstance) return this.constructorInstance;
-
-    // traverse to the top-most derived constructor
-    var currentBase: Class | null = this.base;
-    var instance: Function | null = null;
-    while (currentBase) {
-      instance = currentBase.constructorInstance;
-      if (instance) return instance;
-      currentBase = currentBase.base;
-    }
-    return null;
-  }
-
   /** Tests if a value of this class type is assignable to a target of the specified class type. */
   isAssignableTo(target: Class): bool {
     var current: Class | null = this;

From 5883ec9a0e8abac34f510fdf0c54219dc0c7918f Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Thu, 31 Jan 2019 10:25:03 +0100
Subject: [PATCH 12/12] more tests

---
 tests/compiler/call-super.optimized.wat | 145 +++++++++++++++++++---
 tests/compiler/call-super.ts            |  46 ++++++-
 tests/compiler/call-super.untouched.wat | 157 ++++++++++++++++++++++--
 3 files changed, 323 insertions(+), 25 deletions(-)

diff --git a/tests/compiler/call-super.optimized.wat b/tests/compiler/call-super.optimized.wat
index 61c9388357..2b3f00cd94 100644
--- a/tests/compiler/call-super.optimized.wat
+++ b/tests/compiler/call-super.optimized.wat
@@ -75,7 +75,31 @@
   set_global $~lib/allocator/arena/offset
   get_local $1
  )
- (func $call-super/B#constructor (; 2 ;) (type $FUNCSIG$i) (result i32)
+ (func $call-super/A#constructor (; 2 ;) (type $ii) (param $0 i32) (result i32)
+  get_local $0
+  i32.eqz
+  if
+   i32.const 4
+   call $~lib/allocator/arena/__memory_allocate
+   tee_local $0
+   i32.const 1
+   i32.store
+  end
+  get_local $0
+  i32.load
+  i32.const 1
+  i32.ne
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 6
+   i32.const 4
+   call $~lib/env/abort
+   unreachable
+  end
+  get_local $0
+ )
+ (func $call-super/B#constructor (; 3 ;) (type $FUNCSIG$i) (result i32)
   (local $0 i32)
   i32.const 8
   call $~lib/allocator/arena/__memory_allocate
@@ -86,14 +110,71 @@
   i32.const 2
   i32.store offset=4
   get_local $0
-  i32.eqz
+  call $call-super/A#constructor
+  tee_local $0
+  i32.load
+  i32.const 1
+  i32.ne
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 15
+   i32.const 4
+   call $~lib/env/abort
+   unreachable
+  end
+  get_local $0
+  i32.load offset=4
+  i32.const 2
+  i32.ne
   if
+   i32.const 0
+   i32.const 8
+   i32.const 16
    i32.const 4
-   call $~lib/allocator/arena/__memory_allocate
-   tee_local $0
-   i32.const 1
-   i32.store
+   call $~lib/env/abort
+   unreachable
+  end
+  get_local $0
+ )
+ (func $call-super/test1 (; 4 ;) (type $v)
+  (local $0 i32)
+  call $call-super/B#constructor
+  tee_local $0
+  i32.load
+  i32.const 1
+  i32.ne
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 22
+   i32.const 2
+   call $~lib/env/abort
+   unreachable
+  end
+  get_local $0
+  i32.load offset=4
+  i32.const 2
+  i32.ne
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 23
+   i32.const 2
+   call $~lib/env/abort
+   unreachable
   end
+ )
+ (func $call-super/D#constructor (; 5 ;) (type $FUNCSIG$i) (result i32)
+  (local $0 i32)
+  i32.const 8
+  call $~lib/allocator/arena/__memory_allocate
+  tee_local $0
+  i32.const 1
+  i32.store
+  get_local $0
+  i32.const 2
+  i32.store offset=4
   get_local $0
   i32.load
   i32.const 1
@@ -101,7 +182,7 @@
   if
    i32.const 0
    i32.const 8
-   i32.const 13
+   i32.const 36
    i32.const 4
    call $~lib/env/abort
    unreachable
@@ -113,16 +194,16 @@
   if
    i32.const 0
    i32.const 8
-   i32.const 14
+   i32.const 37
    i32.const 4
    call $~lib/env/abort
    unreachable
   end
   get_local $0
  )
- (func $call-super/test (; 3 ;) (type $v)
+ (func $call-super/test2 (; 6 ;) (type $v)
   (local $0 i32)
-  call $call-super/B#constructor
+  call $call-super/D#constructor
   tee_local $0
   i32.load
   i32.const 1
@@ -130,7 +211,7 @@
   if
    i32.const 0
    i32.const 8
-   i32.const 20
+   i32.const 43
    i32.const 2
    call $~lib/env/abort
    unreachable
@@ -142,20 +223,54 @@
   if
    i32.const 0
    i32.const 8
-   i32.const 21
+   i32.const 44
    i32.const 2
    call $~lib/env/abort
    unreachable
   end
  )
- (func $start (; 4 ;) (type $v)
+ (func $call-super/E#constructor (; 7 ;) (type $FUNCSIG$i) (result i32)
+  (local $0 i32)
+  i32.const 4
+  call $~lib/allocator/arena/__memory_allocate
+  tee_local $0
+  i32.const 1
+  i32.store
+  get_local $0
+  i32.load
+  i32.const 1
+  i32.ne
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 52
+   i32.const 4
+   call $~lib/env/abort
+   unreachable
+  end
+  get_local $0
+ )
+ (func $start (; 8 ;) (type $v)
   i32.const 40
   set_global $~lib/allocator/arena/startOffset
   get_global $~lib/allocator/arena/startOffset
   set_global $~lib/allocator/arena/offset
-  call $call-super/test
+  call $call-super/test1
+  call $call-super/test2
+  call $call-super/E#constructor
+  i32.load
+  i32.const 1
+  i32.ne
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 62
+   i32.const 2
+   call $~lib/env/abort
+   unreachable
+  end
  )
- (func $null (; 5 ;) (type $v)
+ (func $null (; 9 ;) (type $v)
   nop
  )
 )
diff --git a/tests/compiler/call-super.ts b/tests/compiler/call-super.ts
index dab4214d25..939226ea18 100644
--- a/tests/compiler/call-super.ts
+++ b/tests/compiler/call-super.ts
@@ -3,10 +3,12 @@ import "allocator/arena";
 class A {
   a: i32 = 1;
   constructor() {
+    assert(this.a == 1);
   }
 }
 
 class B extends A {
+  // a: i32 = 3; // FIXME: currently duplicate identifier
   b: i32 = 2;
   constructor() {
     super();
@@ -15,10 +17,50 @@ class B extends A {
   }
 }
 
-function test(): void {
+function test1(): void {
   var b = new B();
   assert(b.a == 1);
   assert(b.b == 2);
 }
 
-test();
+test1();
+
+class C {
+  a: i32 = 1;
+}
+
+class D extends C {
+  b: i32 = 2;
+  constructor() {
+    super();
+    assert(this.a == 1);
+    assert(this.b == 2);
+  }
+}
+
+function test2(): void {
+  var d = new D();
+  assert(d.a == 1);
+  assert(d.b == 2);
+}
+
+test2();
+
+class E {
+  a: i32 = 1;
+  constructor() {
+    assert(this.a == 1);
+  }
+}
+
+class F extends E {
+  b: i32 = 2;
+}
+
+function test3(): void {
+  var f = new F();
+  assert(f.a == 1);
+  // assert(f.b == 2); // FIXME: uses E#constructor, not initializing fields
+}
+
+test3();
diff --git a/tests/compiler/call-super.untouched.wat b/tests/compiler/call-super.untouched.wat
index 7e1fb52d89..b7e3eb9c7f 100644
--- a/tests/compiler/call-super.untouched.wat
+++ b/tests/compiler/call-super.untouched.wat
@@ -119,6 +119,19 @@
    tee_local $0
   end
   tee_local $0
+  i32.load
+  i32.const 1
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 6
+   i32.const 4
+   call $~lib/env/abort
+   unreachable
+  end
+  get_local $0
  )
  (func $call-super/B#constructor (; 4 ;) (type $ii) (param $0 i32) (result i32)
   (local $1 i32)
@@ -144,7 +157,7 @@
   if
    i32.const 0
    i32.const 8
-   i32.const 13
+   i32.const 15
    i32.const 4
    call $~lib/env/abort
    unreachable
@@ -157,14 +170,14 @@
   if
    i32.const 0
    i32.const 8
-   i32.const 14
+   i32.const 16
    i32.const 4
    call $~lib/env/abort
    unreachable
   end
   get_local $0
  )
- (func $call-super/test (; 5 ;) (type $v)
+ (func $call-super/test1 (; 5 ;) (type $v)
   (local $0 i32)
   i32.const 0
   call $call-super/B#constructor
@@ -177,8 +190,50 @@
   if
    i32.const 0
    i32.const 8
-   i32.const 20
+   i32.const 22
+   i32.const 2
+   call $~lib/env/abort
+   unreachable
+  end
+  get_local $0
+  i32.load offset=4
+  i32.const 2
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 23
+   i32.const 2
+   call $~lib/env/abort
+   unreachable
+  end
+ )
+ (func $call-super/D#constructor (; 6 ;) (type $ii) (param $0 i32) (result i32)
+  (local $1 i32)
+  block (result i32)
+   i32.const 8
+   call $~lib/memory/memory.allocate
+   set_local $1
+   get_local $1
+   i32.const 1
+   i32.store
+   get_local $1
    i32.const 2
+   i32.store offset=4
+   get_local $1
+  end
+  set_local $0
+  get_local $0
+  i32.load
+  i32.const 1
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 36
+   i32.const 4
    call $~lib/env/abort
    unreachable
   end
@@ -190,13 +245,97 @@
   if
    i32.const 0
    i32.const 8
-   i32.const 21
+   i32.const 37
+   i32.const 4
+   call $~lib/env/abort
+   unreachable
+  end
+  get_local $0
+ )
+ (func $call-super/test2 (; 7 ;) (type $v)
+  (local $0 i32)
+  i32.const 0
+  call $call-super/D#constructor
+  set_local $0
+  get_local $0
+  i32.load
+  i32.const 1
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 43
+   i32.const 2
+   call $~lib/env/abort
+   unreachable
+  end
+  get_local $0
+  i32.load offset=4
+  i32.const 2
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 44
+   i32.const 2
+   call $~lib/env/abort
+   unreachable
+  end
+ )
+ (func $call-super/E#constructor (; 8 ;) (type $ii) (param $0 i32) (result i32)
+  (local $1 i32)
+  get_local $0
+  if (result i32)
+   get_local $0
+  else   
+   block (result i32)
+    i32.const 4
+    call $~lib/memory/memory.allocate
+    set_local $1
+    get_local $1
+    i32.const 1
+    i32.store
+    get_local $1
+   end
+   tee_local $0
+  end
+  tee_local $0
+  i32.load
+  i32.const 1
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 52
+   i32.const 4
+   call $~lib/env/abort
+   unreachable
+  end
+  get_local $0
+ )
+ (func $call-super/test3 (; 9 ;) (type $v)
+  (local $0 i32)
+  i32.const 0
+  call $call-super/E#constructor
+  set_local $0
+  get_local $0
+  i32.load
+  i32.const 1
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 8
+   i32.const 62
    i32.const 2
    call $~lib/env/abort
    unreachable
   end
  )
- (func $start (; 6 ;) (type $v)
+ (func $start (; 10 ;) (type $v)
   get_global $HEAP_BASE
   get_global $~lib/internal/allocator/AL_MASK
   i32.add
@@ -207,8 +346,10 @@
   set_global $~lib/allocator/arena/startOffset
   get_global $~lib/allocator/arena/startOffset
   set_global $~lib/allocator/arena/offset
-  call $call-super/test
+  call $call-super/test1
+  call $call-super/test2
+  call $call-super/test3
  )
- (func $null (; 7 ;) (type $v)
+ (func $null (; 11 ;) (type $v)
  )
 )