Add --parse-all option in order to benchmark and measure the scanner/parser performance.

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index b78a45279e14ebc914ea0cd0dbe4f3ee74655282..f3c7f07b32acf566692d2f7b356532ee4f832888 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -11343,6 +11343,51 @@ RawError* Library::CompileAll() {
 }
 
 
+RawError* Library::ParseAll() {
+  Thread* thread = Thread::Current();
+  Zone* zone = thread->zone();
+  Error& error = Error::Handle(zone);
+  const GrowableObjectArray& libs = GrowableObjectArray::Handle(
+      Isolate::Current()->object_store()->libraries());
+  Library& lib = Library::Handle(zone);
+  Class& cls = Class::Handle(zone);
+  for (int i = 0; i < libs.Length(); i++) {
+    lib ^= libs.At(i);
+    ClassDictionaryIterator it(lib, ClassDictionaryIterator::kIteratePrivate);
+    while (it.HasNext()) {
+      cls = it.GetNextClass();
+      error = cls.EnsureIsFinalized(thread);
+      if (!error.IsNull()) {
+        return error.raw();
+      }
+      error = Compiler::ParseAllFunctions(cls);
+      if (!error.IsNull()) {
+        return error.raw();
+      }
+    }
+  }
+
+  // Inner functions get added to the closures array. As part of compilation

[hausner, 2016/09/09 16:31:07]

I don't think iterating over inner functions is needed. We parse inner functions
while parsing their enclosing function. Thus, this step is just parsing them
*again*.

[siva, 2016/09/23 00:04:04]

But I guess it is representative of what we would do if we had to produce an IR.

[hausner, 2016/09/23 21:57:20]

Sure. On the other hand, in an AOT compiler we would not reparse, but keep the
IR and produce code right away. 

+  // more closures can be added to the end of the array. Compile all the
+  // closures until we have reached the end of the "worklist".
+  const GrowableObjectArray& closures = GrowableObjectArray::Handle(zone,
+      Isolate::Current()->object_store()->closure_functions());
+  Function& func = Function::Handle(zone);
+  for (int i = 0; i < closures.Length(); i++) {
+    func ^= closures.At(i);
+    if (!func.HasCode()) {
+      error = Compiler::ParseFunction(thread, func);
+      if (!error.IsNull()) {
+        return error.raw();
+      }
+      func.ClearICDataArray();
+      func.ClearCode();
+    }
+  }
+  return error.raw();
+}
+
+
 // Return Function::null() if function does not exist in libs.
 RawFunction* Library::GetFunction(const GrowableArray<Library*>& libs,
                                   const char* class_name,