[dart2bytecode, vm] Adjust bytecode file format

* Switch UInt32 from big-endian to little-endian encoding.
* Reorder object kinds, constant tags, type tags and constant pool tags.
* Reorder field and function flags.
* Cleanup yield point marker from source positions.

TEST=ci

Change-Id: I05ee940b6393a478831af11ac93fee9ec1441c4e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/384040
Reviewed-by: Slava Egorov <vegorov@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>

pkg/dart2bytecode/lib/assembler.dart

@@ -105,12 +105,6 @@ class BytecodeAssembler {
     }
   }
 
-  void emitYieldPointSourcePosition(int yieldSourcePosition) {
-    if (!isUnreachable) {
-      sourcePositions.addYieldPoint(offset, yieldSourcePosition);
-    }
-  }
-
   void _grow() {
     final newSize = _buffer.length << 1;
     final newBuffer = new Uint8List(newSize);

pkg/dart2bytecode/lib/bytecode_generator.dart

@@ -525,7 +525,7 @@ class BytecodeGenerator extends RecursiveVisitor {
       flags |= FieldDeclaration.isCovariantFlag;
     }
     if (field.isCovariantByClass) {
-      flags |= FieldDeclaration.isGenericCovariantImplFlag;
+      flags |= FieldDeclaration.isCovariantByClassFlag;
     }
     if (field.isExtensionMember) {
       flags |= FieldDeclaration.isExtensionMemberFlag;
@@ -584,9 +584,6 @@ class BytecodeGenerator extends RecursiveVisitor {
       if (member.isStatic) {
         flags |= FunctionDeclaration.isStaticFlag;
       }
-      if (member.isForwardingStub) {
-        flags |= FunctionDeclaration.isForwardingStubFlag;
-      }
       if (member.isNoSuchMethodForwarder) {
         flags |= FunctionDeclaration.isNoSuchMethodForwarderFlag;
       }
@@ -765,7 +762,7 @@ class BytecodeGenerator extends RecursiveVisitor {
         flags |= ParameterDeclaration.isCovariantFlag;
       }
       if (variable.isCovariantByClass) {
-        flags |= ParameterDeclaration.isGenericCovariantImplFlag;
+        flags |= ParameterDeclaration.isCovariantByClassFlag;
       }
       if (variable.isFinal) {
         flags |= ParameterDeclaration.isFinalFlag;

pkg/dart2bytecode/lib/bytecode_serialization.dart

@@ -194,11 +194,10 @@ class BufferedWriter {
     if (_currentLength > _currentBuffer.length - 4) {
       _grow();
     }
-    // TODO(alexmarkov): consider using native byte order
-    _addByte((value >> 24) & 0xFF);
-    _addByte((value >> 16) & 0xFF);
-    _addByte((value >> 8) & 0xFF);
     _addByte(value & 0xFF);
+    _addByte((value >> 8) & 0xFF);
+    _addByte((value >> 16) & 0xFF);
+    _addByte((value >> 24) & 0xFF);
   }
 
   @pragma('vm:prefer-inline')
@@ -291,10 +290,10 @@ class BufferedReader {
   int readByte() => bytes[_pos++];
 
   int readUInt32() {
-    return (readByte() << 24) |
-        (readByte() << 16) |
+    return readByte() |
         (readByte() << 8) |
-        readByte();
+        (readByte() << 16) |
+        (readByte() << 24);
   }
 
   int readPackedUInt30() {

pkg/dart2bytecode/lib/constant_pool.dart

@@ -110,16 +110,16 @@ type ConstantDynamicCall extends ConstantPoolEntry {
 
 enum ConstantTag {
   kInvalid,
+  kObjectRef,
+  kClass,
+  kType,
   kStaticField,
   kInstanceField,
-  kClass,
   kTypeArgumentsField,
-  kType,
   kClosureFunction,
   kEndClosureFunctionScope,
   kSubtypeTestCache,
   kEmptyTypeArguments,
-  kObjectRef,
   kDirectCall,
   kInterfaceCall,
   kInstantiatedInterfaceCall,

pkg/dart2bytecode/lib/declarations.dart

@@ -313,23 +313,23 @@ class Members extends BytecodeDeclaration {
 }
 
 class FieldDeclaration {
-  static const hasNontrivialInitializerFlag = 1 << 0;
-  static const hasGetterFlag = 1 << 1;
-  static const hasSetterFlag = 1 << 2;
-  static const isReflectableFlag = 1 << 3;
-  static const isStaticFlag = 1 << 4;
-  static const isConstFlag = 1 << 5;
-  static const isFinalFlag = 1 << 6;
-  static const isCovariantFlag = 1 << 7;
-  static const isGenericCovariantImplFlag = 1 << 8;
-  static const hasSourcePositionsFlag = 1 << 9;
-  static const hasAnnotationsFlag = 1 << 10;
-  static const hasPragmaFlag = 1 << 11;
-  static const hasCustomScriptFlag = 1 << 12;
-  static const hasInitializerCodeFlag = 1 << 13;
-  static const isLateFlag = 1 << 14;
-  static const isExtensionMemberFlag = 1 << 15;
-  static const hasInitializerFlag = 1 << 16;
+  static const isStaticFlag = 1 << 0;
+  static const isConstFlag = 1 << 1;
+  static const isFinalFlag = 1 << 2;
+  static const isLateFlag = 1 << 3;
+  static const isCovariantFlag = 1 << 4;
+  static const isCovariantByClassFlag = 1 << 5;
+  static const isExtensionMemberFlag = 1 << 6;
+  static const isReflectableFlag = 1 << 7;
+  static const hasGetterFlag = 1 << 8;
+  static const hasSetterFlag = 1 << 9;
+  static const hasInitializerFlag = 1 << 10;
+  static const hasNontrivialInitializerFlag = 1 << 11;
+  static const hasInitializerCodeFlag = 1 << 12;
+  static const hasSourcePositionsFlag = 1 << 13;
+  static const hasAnnotationsFlag = 1 << 14;
+  static const hasPragmaFlag = 1 << 15;
+  static const hasCustomScriptFlag = 1 << 16;
 
   final int flags;
   final ObjectHandle name;
@@ -472,31 +472,30 @@ class FieldDeclaration {
 }
 
 class FunctionDeclaration {
-  static const isConstructorFlag = 1 << 0;
-  static const isGetterFlag = 1 << 1;
-  static const isSetterFlag = 1 << 2;
-  static const isFactoryFlag = 1 << 3;
-  static const isStaticFlag = 1 << 4;
-  static const isAbstractFlag = 1 << 5;
+  static const isStaticFlag = 1 << 0;
+  static const isAbstractFlag = 1 << 1;
+  static const isGetterFlag = 1 << 2;
+  static const isSetterFlag = 1 << 3;
+  static const isConstructorFlag = 1 << 4;
+  static const isFactoryFlag = 1 << 5;
   static const isConstFlag = 1 << 6;
   static const hasOptionalPositionalParamsFlag = 1 << 7;
   static const hasOptionalNamedParamsFlag = 1 << 8;
   static const hasTypeParamsFlag = 1 << 9;
-  static const isReflectableFlag = 1 << 10;
-  static const isDebuggableFlag = 1 << 11;
-  static const isAsyncFlag = 1 << 12;
-  static const isAsyncStarFlag = 1 << 13;
-  static const isSyncStarFlag = 1 << 14;
-  static const isForwardingStubFlag = 1 << 15;
-  static const isNoSuchMethodForwarderFlag = 1 << 16;
-  static const isNativeFlag = 1 << 17;
+  static const hasParameterFlagsFlag = 1 << 10;
+  static const isExtensionMemberFlag = 1 << 11;
+  static const isReflectableFlag = 1 << 12;
+  static const isDebuggableFlag = 1 << 13;
+  static const isAsyncFlag = 1 << 14;
+  static const isAsyncStarFlag = 1 << 15;
+  static const isSyncStarFlag = 1 << 16;
+  static const isNoSuchMethodForwarderFlag = 1 << 17;
   static const isExternalFlag = 1 << 18;
-  static const hasSourcePositionsFlag = 1 << 19;
-  static const hasAnnotationsFlag = 1 << 20;
-  static const hasPragmaFlag = 1 << 21;
-  static const hasCustomScriptFlag = 1 << 22;
-  static const isExtensionMemberFlag = 1 << 23;
-  static const hasParameterFlagsFlag = 1 << 24;
+  static const isNativeFlag = 1 << 19;
+  static const hasSourcePositionsFlag = 1 << 20;
+  static const hasAnnotationsFlag = 1 << 21;
+  static const hasPragmaFlag = 1 << 22;
+  static const hasCustomScriptFlag = 1 << 23;
 
   final int flags;
   final ObjectHandle name;
@@ -670,9 +669,6 @@ class FunctionDeclaration {
     if ((flags & isSyncStarFlag) != 0) {
       sb.write(', sync*');
     }
-    if ((flags & isForwardingStubFlag) != 0) {
-      sb.write(', forwarding-stub');
-    }
     if ((flags & isNoSuchMethodForwarderFlag) != 0) {
       sb.write(', no-such-method-forwarder');
     }
@@ -751,7 +747,7 @@ class TypeParametersDeclaration {
 class ParameterDeclaration {
   // Parameter flags are written separately (in Code).
   static const isCovariantFlag = 1 << 0;
-  static const isGenericCovariantImplFlag = 1 << 1;
+  static const isCovariantByClassFlag = 1 << 1;
   static const isFinalFlag = 1 << 2;
   static const isRequiredFlag = 1 << 3;
 

pkg/dart2bytecode/lib/object_table.dart

@@ -284,44 +284,44 @@ type BoundAndDefaultType {
 enum ObjectKind {
   kInvalid,
   kLibrary,
+  kScript,
   kClass,
   kMember,
   kClosure,
   kName,
-  kTypeArguments,
   kConstObject,
-  kArgDesc,
-  kScript,
   kType,
+  kTypeArguments,
+  kArgDesc,
 }
 
 enum ConstTag {
   kInvalid,
-  kInstance,
   kInt,
   kDouble,
-  kList,
-  kTearOff,
   kBool,
-  kSymbol,
-  kTearOffInstantiation,
   kString,
+  kSymbol,
+  kInstance,
+  kList,
   kMap,
   kSet,
   kRecord,
+  kTearOff,
+  kTearOffInstantiation,
 }
 
 enum TypeTag {
   kInvalid,
   kDynamic,
   kVoid,
-  kSimpleType,
-  kTypeParameter,
-  kGenericType,
-  kFunctionType,
-  kRecordType,
   kNull,
   kNever,
+  kSimpleType,
+  kGenericType,
+  kTypeParameter,
+  kFunctionType,
+  kRecordType,
 }
 
 /// Name of artificial class containing top-level members of a library.

pkg/dart2bytecode/lib/source_positions.dart

@@ -17,8 +17,6 @@ class SourcePositions extends BytecodeDeclaration {
   // Special value of fileOffset which marks synthetic code without source
   // position.
   static const syntheticCodeMarker = -1;
-  // Special value of fileOffset which marks yield point.
-  static const yieldPointMarker = -2;
 
   final List<int> _positions = <int>[]; // Pairs (PC, fileOffset).
   int _lastPc = 0;
@@ -37,17 +35,6 @@ class SourcePositions extends BytecodeDeclaration {
     }
   }
 
-  void addYieldPoint(int pc, int fileOffset) {
-    assert(pc > _lastPc);
-    assert((fileOffset >= 0) || (fileOffset == syntheticCodeMarker));
-    _positions.add(pc);
-    _positions.add(yieldPointMarker);
-    _positions.add(pc);
-    _positions.add(fileOffset);
-    _lastPc = pc;
-    _lastOffset = fileOffset;
-  }
-
   bool get isEmpty => _positions.isEmpty;
   bool get isNotEmpty => !isEmpty;
 
@@ -83,9 +70,7 @@ class SourcePositions extends BytecodeDeclaration {
     for (int i = 0; i < _positions.length; i += 2) {
       final int pc = _positions[i];
       final int fileOffset = _positions[i + 1];
-      final entry = (fileOffset == yieldPointMarker)
-          ? 'yield point'
-          : 'source position $fileOffset';
+      final entry = 'source position $fileOffset';
       if (map[pc] == null) {
         map[pc] = entry;
       } else {

pkg/dart2bytecode/testcases/type_ops.dart.expect

@@ -588,7 +588,7 @@ ConstantPool {
 }
 
 
-Function 'foo7', reflectable, debuggable, forwarding-stub
+Function 'foo7', reflectable, debuggable
     parameters [dart:core::num 'b', dart:core::String 'c'] (required: 2)
     return-type void
 

runtime/vm/bytecode_reader.cc

@@ -438,16 +438,16 @@ intptr_t BytecodeReaderHelper::ReadConstantPool(const Function& function,
   // be kept in sync with pkg/dart2bytecode/lib/constant_pool.dart.
   enum ConstantPoolTag {
     kInvalid,
+    kObjectRef,
+    kClass,
+    kType,
     kStaticField,
     kInstanceField,
-    kClass,
     kTypeArgumentsField,
-    kType,
     kClosureFunction,
     kEndClosureFunctionScope,
     kSubtypeTestCache,
     kEmptyTypeArguments,
-    kObjectRef,
     kDirectCall,
     kInterfaceCall,
     kInstantiatedInterfaceCall,
@@ -879,15 +879,15 @@ ObjectPtr BytecodeReaderHelper::ReadObjectContents(uint32_t header) {
   enum ObjectKind {
     kInvalid,
     kLibrary,
+    kScript,
     kClass,
     kMember,
     kClosure,
     kName,
-    kTypeArguments,
     kConstObject,
-    kArgDesc,
-    kScript,
     kType,
+    kTypeArguments,
+    kArgDesc,
   };
 
   // Member flags, must be in sync with _MemberHandle constants in
@@ -1053,18 +1053,18 @@ ObjectPtr BytecodeReaderHelper::ReadConstObject(intptr_t tag) {
   // pkg/dart2bytecode/lib/object_table.dart.
   enum ConstTag {
     kInvalid,
-    kInstance,
     kInt,
     kDouble,
-    kList,
-    kTearOff,
     kBool,
-    kSymbol,
-    kTearOffInstantiation,
     kString,
+    kSymbol,
+    kInstance,
+    kList,
     kMap,
     kSet,
     kRecord,
+    kTearOff,
+    kTearOffInstantiation,
   };
 
   switch (tag) {
@@ -1250,13 +1250,13 @@ ObjectPtr BytecodeReaderHelper::ReadType(intptr_t tag,
     kInvalid,
     kDynamic,
     kVoid,
-    kSimpleType,
-    kTypeParameter,
-    kGenericType,
-    kFunctionType,
-    kRecordType,
     kNull,
     kNever,
+    kSimpleType,
+    kGenericType,
+    kTypeParameter,
+    kFunctionType,
+    kRecordType,
   };
 
   // FunctionType flags, must be in sync with _FunctionTypeHandle constants in
@@ -1479,23 +1479,23 @@ void BytecodeReaderHelper::ReadFieldDeclarations(const Class& cls,
                                                  bool discard_fields) {
   // Field flags, must be in sync with FieldDeclaration constants in
   // pkg/dart2bytecode/lib/declarations.dart.
-  const int kHasNontrivialInitializerFlag = 1 << 0;
-  const int kHasGetterFlag = 1 << 1;
-  const int kHasSetterFlag = 1 << 2;
-  const int kIsReflectableFlag = 1 << 3;
-  const int kIsStaticFlag = 1 << 4;
-  const int kIsConstFlag = 1 << 5;
-  const int kIsFinalFlag = 1 << 6;
-  const int kIsCovariantFlag = 1 << 7;
-  const int kIsGenericCovariantImplFlag = 1 << 8;
-  const int kHasSourcePositionsFlag = 1 << 9;
-  const int kHasAnnotationsFlag = 1 << 10;
-  const int kHasPragmaFlag = 1 << 11;
-  const int kHasCustomScriptFlag = 1 << 12;
-  const int kHasInitializerCodeFlag = 1 << 13;
-  const int kIsLateFlag = 1 << 14;
-  const int kIsExtensionMemberFlag = 1 << 15;
-  const int kHasInitializerFlag = 1 << 16;
+  const int kIsStaticFlag = 1 << 0;
+  const int kIsConstFlag = 1 << 1;
+  const int kIsFinalFlag = 1 << 2;
+  const int kIsLateFlag = 1 << 3;
+  const int kIsCovariantFlag = 1 << 4;
+  const int kIsCovariantByClassFlag = 1 << 5;
+  const int kIsExtensionMemberFlag = 1 << 6;
+  const int kIsReflectableFlag = 1 << 7;
+  const int kHasGetterFlag = 1 << 8;
+  const int kHasSetterFlag = 1 << 9;
+  const int kHasInitializerFlag = 1 << 10;
+  const int kHasNontrivialInitializerFlag = 1 << 11;
+  const int kHasInitializerCodeFlag = 1 << 12;
+  const int kHasSourcePositionsFlag = 1 << 13;
+  const int kHasAnnotationsFlag = 1 << 14;
+  const int kHasPragmaFlag = 1 << 15;
+  const int kHasCustomScriptFlag = 1 << 16;
 
   const int num_fields = reader_.ReadListLength();
   if ((num_fields == 0) && !cls.is_enum_class()) {
@@ -1546,8 +1546,7 @@ void BytecodeReaderHelper::ReadFieldDeclarations(const Class& cls,
 
     field.set_has_pragma(has_pragma);
     field.set_is_covariant((flags & kIsCovariantFlag) != 0);
-    field.set_is_generic_covariant_impl((flags & kIsGenericCovariantImplFlag) !=
-                                        0);
+    field.set_is_generic_covariant_impl((flags & kIsCovariantByClassFlag) != 0);
     field.set_has_nontrivial_initializer(has_nontrivial_initializer);
     field.set_is_extension_member(is_extension_member);
     field.set_has_initializer(has_initializer);
@@ -1728,31 +1727,30 @@ InstancePtr BytecodeReaderHelper::Canonicalize(const Instance& instance) {
 void BytecodeReaderHelper::ReadFunctionDeclarations(const Class& cls) {
   // Function flags, must be in sync with FunctionDeclaration constants in
   // pkg/dart2bytecode/lib/declarations.dart.
-  const int kIsConstructorFlag = 1 << 0;
-  const int kIsGetterFlag = 1 << 1;
-  const int kIsSetterFlag = 1 << 2;
-  const int kIsFactoryFlag = 1 << 3;
-  const int kIsStaticFlag = 1 << 4;
-  const int kIsAbstractFlag = 1 << 5;
+  const int kIsStaticFlag = 1 << 0;
+  const int kIsAbstractFlag = 1 << 1;
+  const int kIsGetterFlag = 1 << 2;
+  const int kIsSetterFlag = 1 << 3;
+  const int kIsConstructorFlag = 1 << 4;
+  const int kIsFactoryFlag = 1 << 5;
   const int kIsConstFlag = 1 << 6;
   const int kHasOptionalPositionalParamsFlag = 1 << 7;
   const int kHasOptionalNamedParamsFlag = 1 << 8;
   const int kHasTypeParamsFlag = 1 << 9;
-  const int kIsReflectableFlag = 1 << 10;
-  const int kIsDebuggableFlag = 1 << 11;
-  const int kIsAsyncFlag = 1 << 12;
-  const int kIsAsyncStarFlag = 1 << 13;
-  const int kIsSyncStarFlag = 1 << 14;
-  // const int kIsForwardingStubFlag = 1 << 15;
-  const int kIsNoSuchMethodForwarderFlag = 1 << 16;
-  const int kIsNativeFlag = 1 << 17;
+  const int kHasParameterFlagsFlag = 1 << 10;
+  const int kIsExtensionMemberFlag = 1 << 11;
+  const int kIsReflectableFlag = 1 << 12;
+  const int kIsDebuggableFlag = 1 << 13;
+  const int kIsAsyncFlag = 1 << 14;
+  const int kIsAsyncStarFlag = 1 << 15;
+  const int kIsSyncStarFlag = 1 << 16;
+  const int kIsNoSuchMethodForwarderFlag = 1 << 17;
   const int kIsExternalFlag = 1 << 18;
-  const int kHasSourcePositionsFlag = 1 << 19;
-  const int kHasAnnotationsFlag = 1 << 20;
-  const int kHasPragmaFlag = 1 << 21;
-  const int kHasCustomScriptFlag = 1 << 22;
-  const int kIsExtensionMemberFlag = 1 << 23;
-  const int kHasParameterFlagsFlag = 1 << 24;
+  const int kIsNativeFlag = 1 << 19;
+  const int kHasSourcePositionsFlag = 1 << 20;
+  const int kHasAnnotationsFlag = 1 << 21;
+  const int kHasPragmaFlag = 1 << 22;
+  const int kHasCustomScriptFlag = 1 << 23;
 
   const intptr_t num_functions = reader_.ReadListLength();
   ASSERT(function_index_ + num_functions == functions_->Length());
@@ -2200,7 +2198,7 @@ void BytecodeReaderHelper::ReadParameterCovariance(
       if ((flags & Parameter::kIsCovariantFlag) != 0) {
         is_covariant->Add(i);
       }
-      if ((flags & Parameter::kIsGenericCovariantImplFlag) != 0) {
+      if ((flags & Parameter::kIsCovariantByClassFlag) != 0) {
         is_generic_covariant_impl->Add(i);
       }
     }

runtime/vm/bytecode_reader.h

@@ -52,7 +52,9 @@ class Reader : public ValueObject {
     ASSERT((size_ >= 4) && (offset >= 0) && (offset <= size_ - 4));
     uint32_t value =
         LoadUnaligned(reinterpret_cast<const uint32_t*>(raw_buffer_ + offset));
-    return Utils::BigEndianToHost32(value);
+    // All supported platforms are little-endian, so there is no need to
+    // convert from little-endian to host.
+    return value;
   }
 
   uint32_t ReadUInt32() {
@@ -265,7 +267,7 @@ class BytecodeReaderHelper : public ValueObject {
   // pkg/dart2bytecode/lib/declarations.dart.
   struct Parameter {
     static const int kIsCovariantFlag = 1 << 0;
-    static const int kIsGenericCovariantImplFlag = 1 << 1;
+    static const int kIsCovariantByClassFlag = 1 << 1;
     static const int kIsFinalFlag = 1 << 2;
     static const int kIsRequiredFlag = 1 << 3;
   };