[V8][Wasm] Wasm throws.

src/runtime/runtime-wasm.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/assembler.h"
 #include "src/compiler/wasm-compiler.h"
 #include "src/conversions.h"
 #include "src/debug/debug.h"
 #include "src/factory.h"
 #include "src/frames-inl.h"
 #include "src/objects-inl.h"
 #include "src/v8memory.h"
 #include "src/wasm/wasm-module.h"
 
 namespace v8 {
 namespace internal {
 
 RUNTIME_FUNCTION(Runtime_WasmGrowMemory) {
   HandleScope scope(isolate);
   DCHECK_EQ(1, args.length());
   uint32_t delta_pages = 0;
   CHECK(args[0]->ToUint32(&delta_pages));

[Michael Starzinger, 2016/09/15 12:33:36]

nit: I know this is not your code, but for bonus points this could use
CONVERT_UINT32_ARG_CHECKED as well.

[John, 2016/09/15 12:42:05]

CONVERT_UINT32_ARG_CHECKED is not available. I changed to
CONVERT_INT32_ARG_CHECKED, which can be a problem if delta_pages is > 2**32 -1.
Should I keep my change, or revert, or add a new macro?

[Michael Starzinger, 2016/09/15 12:51:08]

https://cs.chromium.org/chromium/src/v8/src/runtime/runtime-utils.h?q=CONVERT...

[John, 2016/09/15 14:03:08]

Done.

   Handle<JSObject> module_instance;
 
   {
     // Get the module JSObject
     DisallowHeapAllocation no_allocation;
     const Address entry = Isolate::c_entry_fp(isolate->thread_local_top());
     Address pc =
         Memory::Address_at(entry + StandardFrameConstants::kCallerPCOffset);
     Code* code =
         isolate->inner_pointer_to_code_cache()->GetCacheEntry(pc)->code;
@@ skipping 75 matching lines @@
   return *isolate->factory()->NewNumberFromInt(old_size /
                                                wasm::WasmModule::kPageSize);
 }
 
 RUNTIME_FUNCTION(Runtime_WasmThrowTypeError) {
   HandleScope scope(isolate);
   DCHECK_EQ(0, args.length());
   THROW_NEW_ERROR_RETURN_FAILURE(
       isolate, NewTypeError(MessageTemplate::kWasmTrapTypeError));
 }
+
+RUNTIME_FUNCTION(Runtime_WasmThrow) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(2, args.length());
+  Object* upper = args[1];
+  Object* lower = args[0];

[Michael Starzinger, 2016/09/15 12:33:36]

nit: Please use CONVERT_SMI_ARG_CHECKED here.

[John, 2016/09/15 12:42:05]

Done.

+
+  const int32_t thrown_value =
+      (Smi::cast(upper)->value() << 16) | Smi::cast(lower)->value();
+
+  return isolate->Throw(*isolate->factory()->NewNumberFromInt(thrown_value));
+}
+
 }  // namespace internal
 }  // namespace v8