vm/service/observatory: Add coverage for functions, some tests, and fix buggy filter

runtime/vm/service.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/service.h"
 
 #include "include/dart_api.h"
 #include "platform/globals.h"
 
 #include "vm/compiler.h"
@@ skipping 176 matching lines @@
                                const String& script_url,
                                const Class& cls,
                                const Function& func) const {
     return cls.raw() == cls_.raw();
   }
  private:
   const Class& cls_;
 };
 
 
+class FunctionCoverageFilter : public CoverageFilter {
+ public:
+  explicit FunctionCoverageFilter(const Function& func) : func_(func) {}
+  bool ShouldOutputCoverageFor(const Library& lib,
+                               const String& script_url,
+                               const Class& cls,
+                               const Function& func) const {
+    return func.raw() == func_.raw();
+  }
+ private:
+  const Function& func_;
+};
+
+
 static uint8_t* allocator(uint8_t* ptr, intptr_t old_size, intptr_t new_size) {
   void* new_ptr = realloc(reinterpret_cast<void*>(ptr), new_size);
   return reinterpret_cast<uint8_t*>(new_ptr);
 }
 
 
 static void SendIsolateServiceMessage(Dart_NativeArguments args) {
   NativeArguments* arguments = reinterpret_cast<NativeArguments*>(args);
   Isolate* isolate = arguments->isolate();
   StackZone zone(isolate);
@@ skipping 897 matching lines @@
   func ^= cls.InvocationDispatcherFunctionFromIndex(id);
   if (func.IsNull()) {
     PrintError(js, "Dispatcher %" Pd " not found", id);
     return true;
   }
   func.PrintJSON(js, false);
   return true;
 }
 
 
+static bool HandleClassesFunctionsCoverage(
+    Isolate* isolate, const Function& func, JSONStream* js) {
+  FunctionCoverageFilter filter(func);
+  CodeCoverage::PrintJSON(isolate, js, &filter);
+  return true;
+}
+
+
 static bool HandleClassesFunctions(Isolate* isolate, const Class& cls,
                                    JSONStream* js) {
   intptr_t id;
-  if (js->num_arguments() > 4) {
+  if (js->num_arguments() > 5) {
     PrintError(js, "Command too long");
     return true;
   }
   if (!GetIntegerId(js->GetArgument(3), &id)) {
     PrintError(js, "Must specify collection object id: functions/id");
     return true;
   }
   Function& func = Function::Handle();
   func ^= cls.FunctionFromIndex(id);
   if (func.IsNull()) {
     PrintError(js, "Function %" Pd " not found", id);
     return true;
   }
-  func.PrintJSON(js, false);
+  if (js->num_arguments() == 4) {
+    func.PrintJSON(js, false);
+    return true;
+  } else {
+    const char* subcollection = js->GetArgument(4);
+    if (strcmp(subcollection, "coverage") == 0) {
+      return HandleClassesFunctionsCoverage(isolate, func, js);
+    } else {
+      PrintError(js, "Invalid sub collection %s", subcollection);
+      return true;
+    }
+  }
+  UNREACHABLE();
   return true;
 }
 
 
 static bool HandleClassesImplicitClosures(Isolate* isolate, const Class& cls,
                                           JSONStream* js) {
   intptr_t id;
   if (js->num_arguments() > 4) {
     PrintError(js, "Command too long");
     return true;
@@ skipping 1205 matching lines @@
   while (current != NULL) {
     if (strcmp(name, current->name()) == 0) {
       return current;
     }
     current = current->next();
   }
   return NULL;
 }
 
 }  // namespace dart