[vm/bytecode] Include source info and asserts into platform with bytecode

* Include source positions, source text (if provided by front-end, which is
  controlled by a separate option) and assertions into platform with bytecode.
  Also use environment defines if provided.

* Omit bytecode for synthetic static fields '_redirecting#' injected
  by front-end, as they contain invalid AST nodes (taking tear-off of
  a constructor). This is needed to avoid emitting bytecode which cannot be
  loaded.

* Correctly merge source information such as source text and line numbers
  in bytecode generator if the script was originally created for an
  anonymous mixin application without such information.

* Always include import URIs into source information, even if other information is
  excluded (for members in anonymous mixin applications / noSuchMethod forwarders /
  forwarding stubs).

* Set native resolvers for vm/cc/PrintJSON test, as printing all objects to JSON
  involves collecting token positions, which may read bytecode from platform and
  need native resolvers to process native method entries.

Change-Id: I971e880c25439c0ec69db3a231a0085ccd5d15ad
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/113780
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Régis Crelier <regis@google.com>

pkg/front_end/tool/_fasta/entry_points.dart

@@ -19,6 +19,7 @@ import 'package:kernel/target/targets.dart' show Target, TargetFlags, getTarget;
 import 'package:kernel/type_environment.dart' show SubtypeTester;
 
 import 'package:vm/bytecode/gen_bytecode.dart' show generateBytecode;
+import 'package:vm/bytecode/options.dart' show BytecodeOptions;
 
 import 'package:front_end/src/api_prototype/compiler_options.dart'
     show CompilerOptions;
@@ -329,7 +330,12 @@ Future<void> compilePlatformInternal(CompilerContext c, Uri fullOutput,
   c.options.ticker.logMs("Wrote outline to ${outlineOutput.toFilePath()}");
 
   if (c.options.bytecode) {
-    generateBytecode(result.component);
+    generateBytecode(result.component,
+        options: new BytecodeOptions(
+            enableAsserts: true,
+            emitSourceFiles: true,
+            emitSourcePositions: true,
+            environmentDefines: c.options.environmentDefines));
   }
 
   await writeComponentToFile(result.component, fullOutput,

pkg/vm/lib/bytecode/declarations.dart

@@ -220,22 +220,20 @@ class SourceFile {
   static const hasLineStartsFlag = 1 << 0;
   static const hasSourceFlag = 1 << 1;
 
-  int flags;
   final ObjectHandle importUri;
-  final LineStarts lineStarts;
-  final String source;
+  LineStarts lineStarts;
+  String source;
 
-  SourceFile(this.importUri, this.lineStarts, this.source) {
-    flags = 0;
+  SourceFile(this.importUri, [this.lineStarts, this.source]);
+
+  void write(BufferedWriter writer) {
+    int flags = 0;
     if (lineStarts != null) {
       flags |= hasLineStartsFlag;
     }
     if (source != null && source != '') {
       flags |= hasSourceFlag;
     }
-  }
-
-  void write(BufferedWriter writer) {
     writer.writePackedUInt30(flags);
     writer.writePackedObject(importUri);
     if ((flags & hasLineStartsFlag) != 0) {
@@ -261,11 +259,13 @@ class SourceFile {
   @override
   String toString() {
     final StringBuffer sb = new StringBuffer();
-    sb.writeln('SourceFile $importUri');
-    sb.writeln('------------------------------------------------');
-    sb.write(source);
-    sb.writeln('------------------------------------------------');
-    sb.writeln(lineStarts);
+    sb.write('source: import-uri $importUri');
+    if (source != null && source != '') {
+      sb.write(', ${source.length} text chars');
+    }
+    if (lineStarts != null) {
+      sb.write(', ${lineStarts.lineStarts.length} line starts');
+    }
     return sb.toString();
   }
 }

pkg/vm/lib/bytecode/gen_bytecode.dart

@@ -211,30 +211,33 @@ class BytecodeGenerator extends RecursiveVisitor<Null> {
     return members;
   }
 
-  ObjectHandle getScript(Uri uri, bool includeSource) {
+  ObjectHandle getScript(Uri uri, bool includeSourceInfo) {
     SourceFile source;
-    if (includeSource &&
-        (options.emitSourceFiles || options.emitSourcePositions)) {
-      source = bytecodeComponent.uriToSource[uri];
-      if (source == null) {
-        final astSource = astUriToSource[uri];
-        if (astSource != null) {
+    if (options.emitSourceFiles || options.emitSourcePositions) {
+      final astSource = astUriToSource[uri];
+      if (astSource != null) {
+        source = bytecodeComponent.uriToSource[uri];
+        if (source == null) {
           final importUri =
               objectTable.getNameHandle(null, astSource.importUri.toString());
-          LineStarts lineStarts;
-          if (options.emitSourcePositions) {
-            lineStarts = new LineStarts(astSource.lineStarts);
-            bytecodeComponent.lineStarts.add(lineStarts);
-          }
-          String text = '';
-          if (options.emitSourceFiles) {
-            text = astSource.cachedText ??
-                utf8.decode(astSource.source, allowMalformed: true);
-          }
-          source = new SourceFile(importUri, lineStarts, text);
+          source = new SourceFile(importUri);
           bytecodeComponent.sourceFiles.add(source);
           bytecodeComponent.uriToSource[uri] = source;
         }
+        if (options.emitSourcePositions &&
+            includeSourceInfo &&
+            source.lineStarts == null) {
+          LineStarts lineStarts = new LineStarts(astSource.lineStarts);
+          bytecodeComponent.lineStarts.add(lineStarts);
+          source.lineStarts = lineStarts;
+        }
+        if (options.emitSourceFiles &&
+            includeSourceInfo &&
+            source.source == null) {
+          String text = astSource.cachedText ??
+              utf8.decode(astSource.source, allowMalformed: true);
+          source.source = text;
+        }
       }
     }
     return objectTable.getScriptHandle(uri, source);
@@ -777,6 +780,16 @@ class BytecodeGenerator extends RecursiveVisitor<Null> {
       return false;
     }
     if (member is Field) {
+      // TODO(dartbug.com/34277)
+      // Front-end inserts synthetic static fields "_redirecting#" to record
+      // information about redirecting constructors in kernel.
+      // The problem is that initializers of these synthetic static fields
+      // contain incorrect kernel AST, e.g. StaticGet which takes tear-off
+      // of a constructor. Do not generate bytecode for them, as they should
+      // never be used.
+      if (member.isStatic && member.name.name == "_redirecting#") {
+        return false;
+      }
       return hasInitializerCode(member);
     }
     return true;
@@ -3083,6 +3096,8 @@ class BytecodeGenerator extends RecursiveVisitor<Null> {
     } else if (target is Procedure) {
       if (target.isGetter) {
         _genDirectCall(target, objectTable.getArgDescHandle(0), 0, isGet: true);
+      } else if (target.isFactory || target.isRedirectingFactoryConstructor) {
+        throw 'Unexpected target for StaticGet: factory $target';
       } else {
         asm.emitPushConstant(cp.addObjectRef(new TearOffConstant(target)));
       }

pkg/vm/lib/bytecode/object_table.dart

@@ -1592,8 +1592,7 @@ class _ScriptHandle extends ObjectHandle {
   bool operator ==(other) => other is _ScriptHandle && this.uri == other.uri;
 
   @override
-  String toString() =>
-      "$uri${source != null ? '(source ${source.importUri})' : ''}";
+  String toString() => "$uri${source != null ? '($source)' : ''}";
 }
 
 class ObjectTable implements ObjectWriter, ObjectReader {

runtime/vm/class_finalizer.cc

@@ -1155,12 +1155,6 @@ void ClassFinalizer::FinalizeClass(const Class& cls) {
   }
   // Mark as loaded and finalized.
   cls.Finalize();
-  // Every class should have at least a constructor, unless it is a top level
-  // class or a typedef class. The Kernel frontend does not create an implicit
-  // constructor for abstract classes.
-  // Moreover, Dart 2 precompiler (TFA) can tree shake all members if unused.
-  ASSERT(FLAG_precompiled_mode || cls.IsTopLevel() || cls.IsTypedefClass() ||
-         cls.is_abstract() || (Array::Handle(cls.functions()).Length() > 0));
   FinalizeMemberTypes(cls);
   // Run additional checks after all types are finalized.
   if (FLAG_use_cha_deopt) {

runtime/vm/object_test.cc

@@ -4,6 +4,9 @@
 
 #include "include/dart_api.h"
 
+#include "bin/builtin.h"
+#include "bin/vmservice_impl.h"
+
 #include "platform/globals.h"
 
 #include "vm/class_finalizer.h"
@@ -3974,6 +3977,15 @@ class ObjectAccumulator : public ObjectVisitor {
 };
 
 ISOLATE_UNIT_TEST_CASE(PrintJSON) {
+  // Set native resolvers in case we need to read native methods.
+  {
+    TransitionVMToNative transition(thread);
+    bin::Builtin::SetNativeResolver(bin::Builtin::kBuiltinLibrary);
+    bin::Builtin::SetNativeResolver(bin::Builtin::kIOLibrary);
+    bin::Builtin::SetNativeResolver(bin::Builtin::kCLILibrary);
+    bin::VmService::SetNativeResolver();
+  }
+
   Heap* heap = Isolate::Current()->heap();
   heap->CollectAllGarbage();
   GrowableArray<Object*> objects;