[observatory] Report AppJIT/AOT feature string.

TEST=examine main page
Change-Id: I368b96e1a871a8d5da4cfab5c3fcf7c297a589be
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/215945
Reviewed-by: Siva Annamalai <[email protected]>
Commit-Queue: Ryan Macnak <[email protected]>

Author: rmacnak-google

runtime/observatory/lib/src/elements/vm_view.dart

@@ -258,6 +258,16 @@ class VMViewElement extends CustomElement implements Renderable {
                   ..classes = ['memberValue']
                   ..text = _vm.version
               ],
+            new DivElement()
+              ..classes = ['memberItem']
+              ..children = <Element>[
+                new DivElement()
+                  ..classes = ['memberName']
+                  ..text = 'features',
+                new DivElement()
+                  ..classes = ['memberValue']
+                  ..text = _vm.features
+              ],
             new DivElement()
               ..classes = ['memberItem']
               ..children = <Element>[

runtime/observatory/lib/src/models/objects/vm.dart

@@ -26,6 +26,8 @@ abstract class VM implements VMRef {
   /// The Dart VM version string.
   String get version;
 
+  String get features;
+
   String get embedder;
 
   /// The amount of memory currently allocated by native code in zones.

runtime/observatory/lib/src/service/object.dart

@@ -672,6 +672,7 @@ abstract class VM extends ServiceObjectOwner implements M.VM {
   final List<Service> services = <Service>[];
 
   String version = 'unknown';
+  String features = 'unknown';
   String hostCPU = 'unknown';
   String targetCPU = 'unknown';
   String embedder = 'unknown';
@@ -1030,6 +1031,7 @@ abstract class VM extends ServiceObjectOwner implements M.VM {
 
     _loaded = true;
     version = map['version'];
+    features = map['_features'] ?? 'unknown';
     hostCPU = map['hostCPU'];
     targetCPU = map['targetCPU'];
     architectureBits = map['architectureBits'];

runtime/vm/dart.cc

@@ -1091,7 +1091,7 @@ const char* Dart::FeaturesString(IsolateGroup* isolate_group,
   do {                                                                         \
     const bool value =                                                         \
         isolate_group != nullptr ? isolate_group->name() : flag;               \
-    ADD_FLAG(#name, value);                                                    \
+    ADD_FLAG(name, value);                                                     \
   } while (0);
 
   if (Snapshot::IncludesCode(kind)) {
@@ -1134,7 +1134,9 @@ const char* Dart::FeaturesString(IsolateGroup* isolate_group,
 #error What architecture?
 #endif
 #if defined(DART_COMPRESSED_POINTERS)
-    buffer.AddString(" compressed");
+    buffer.AddString(" compressed-pointers");
+#else
+    buffer.AddString(" no-compressed-pointers");
 #endif
   }
 

runtime/vm/service.cc

@@ -4889,6 +4889,12 @@ void Service::PrintJSONForVM(JSONStream* js, bool ref) {
   jsobj.AddProperty("operatingSystem", OS::Name());
   jsobj.AddProperty("targetCPU", CPU::Id());
   jsobj.AddProperty("version", Version::String());
+#if defined(DART_PRECOMPILED_RUNTIME)
+  Snapshot::Kind kind = Snapshot::kFullAOT;
+#else
+  Snapshot::Kind kind = Snapshot::kFullJIT;
+#endif
+  jsobj.AddProperty("_features", Dart::FeaturesString(nullptr, true, kind));
   jsobj.AddProperty("_profilerMode", FLAG_profile_vm ? "VM" : "Dart");
   jsobj.AddProperty64("_nativeZoneMemoryUsage",
                       ApiNativeScope::current_memory_usage());