[wasm] asm.js - Check stdlib.NaN is valid, prepare for the rest.

src/asmjs/asm-js.cc

Index: src/asmjs/asm-js.cc
diff --git a/src/asmjs/asm-js.cc b/src/asmjs/asm-js.cc
index cb44ec237a2f3c48267d1d834fb3b6a2ee4b867f..8ea367e8006cea921ada41a6f6b37f580cf1d526 100644
--- a/src/asmjs/asm-js.cc
+++ b/src/asmjs/asm-js.cc
@@ -74,16 +74,56 @@ MaybeHandle<FixedArray> AsmJs::ConvertAsmToWasm(ParseInfo* info) {
                     internal::wasm::kAsmJsOrigin);
   DCHECK(!compiled.is_null());
 
-  Handle<FixedArray> result = info->isolate()->factory()->NewFixedArray(2);
+  wasm::AsmTyper::StdlibSet uses = typer.StdlibUses();
+  Handle<FixedArray> uses_array =
+      info->isolate()->factory()->NewFixedArray(static_cast<int>(uses.size()));
+  int count = 0;
+  for (auto i : uses) {
+    uses_array->set(count++, Smi::FromInt(i));
+  }
+
+  Handle<FixedArray> result = info->isolate()->factory()->NewFixedArray(3);
   result->set(0, *compiled.ToHandleChecked());
   result->set(1, *foreign_globals);
+  result->set(2, *uses_array);
   return result;
 }
 
+bool AsmJs::IsStdlibValid(i::Isolate* isolate, Handle<FixedArray> wasm_data,
+                          Handle<JSReceiver> stdlib) {
+  i::Handle<i::FixedArray> uses(i::FixedArray::cast(wasm_data->get(2)));
+  for (int i = 0; i < uses->length(); ++i) {
+    int32_t kind;
+    if (!uses->get(i)->ToInt32(&kind)) {
+      continue;
+    }
+    switch (kind) {
+      case wasm::AsmTyper::StandardMember::kNaN: {
+        i::Handle<i::Name> name(isolate->factory()->InternalizeOneByteString(
+            STATIC_CHAR_VECTOR("NaN")));
+        i::MaybeHandle<i::Object> maybe_value =
+            i::Object::GetProperty(stdlib, name);
+        if (maybe_value.is_null()) {
+          return false;
+        }
+        i::Handle<i::Object> value = maybe_value.ToHandleChecked();
+        if (!value->IsNaN()) {
+          return false;
+        }

[titzer, 2016/08/19 10:00:28]

Do you want to return true here and then false for others (default case)?

[bradn, 2016/08/19 17:29:08]

Actually not, because this needs to loop to check each.

Separated out per member check into a separate method to make this more clear.

+      } break;
+
+      default: {
+        // TODO(bradnelson): Implement check for the others
+      }
+    }
+  }
+  return true;
+}
+
 MaybeHandle<Object> AsmJs::InstantiateAsmWasm(i::Isolate* isolate,
                                               Handle<FixedArray> wasm_data,
                                               Handle<JSArrayBuffer> memory,
-                                              Handle<JSObject> foreign) {
+                                              Handle<JSReceiver> foreign) {
   i::Handle<i::FixedArray> compiled(i::FixedArray::cast(wasm_data->get(0)));
   i::Handle<i::FixedArray> foreign_globals(
       i::FixedArray::cast(wasm_data->get(1)));