[wasm] Enforce module size limit early enough

src/wasm/wasm-js.cc

Index: src/wasm/wasm-js.cc
diff --git a/src/wasm/wasm-js.cc b/src/wasm/wasm-js.cc
index a3a42cdc99f7af64952099a2b21cc9c839f7f6f8..eea0e756fde377bda7ea38dc307dfdddb176c243 100644
--- a/src/wasm/wasm-js.cc
+++ b/src/wasm/wasm-js.cc
@@ -151,6 +151,13 @@ i::wasm::ModuleWireBytes GetFirstArgumentAsBytes(
   if (start == nullptr || end == start) {
     thrower->CompileError("BufferSource argument is empty");
   }
+  if (end - start > static_cast<ssize_t>(i::wasm::kV8MaxWasmModuleSize)) {
+    thrower->RangeError("buffer source exceeds maximum size of %" PRId64
+                        " (is %" PRId64 ")",
+                        static_cast<int64_t>(i::wasm::kV8MaxWasmModuleSize),

[titzer, 2017/02/21 15:10:22]

for size_t you can use %zu as the format string.

[Clemens Hammacher, 2017/02/21 17:48:16]

Done.

+                        static_cast<int64_t>(end - start));
+  }
+  if (thrower->error()) return i::wasm::ModuleWireBytes(nullptr, nullptr);
   // TODO(titzer): use the handle as well?
   return i::wasm::ModuleWireBytes(start, end);
 }