[wasm] CompileAndRunWasmModule: return when decoding fails.

src/wasm/wasm-module.cc

 // Copyright 2015 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/base/atomic-utils.h"
 #include "src/macro-assembler.h"
 #include "src/objects.h"
 #include "src/property-descriptor.h"
 #include "src/v8.h"
 
@@ skipping 1021 matching lines @@
                                 const byte* module_end, bool asm_js) {
   HandleScope scope(isolate);
   Zone zone(isolate->allocator());
   ErrorThrower thrower(isolate, "CompileAndRunWasmModule");
 
   // Decode the module, but don't verify function bodies, since we'll
   // be compiling them anyway.
   ModuleResult decoding_result =
       DecodeWasmModule(isolate, &zone, module_start, module_end, false,
                        asm_js ? kAsmJsOrigin : kWasmOrigin);
+
+  std::unique_ptr<const WasmModule> module(decoding_result.val);
   if (decoding_result.failed()) {
     // Module verification failed. throw.
     thrower.Error("WASM.compileRun() failed: %s",
                   decoding_result.error_msg.get());
+    return -1;
   }
-  std::unique_ptr<const WasmModule> module(decoding_result.val);
 
   if (module->import_table.size() > 0) {
     thrower.Error("Not supported: module has imports.");
   }
   if (module->export_table.size() == 0) {
     thrower.Error("Not supported: module has no exports.");
   }
 
   if (thrower.error()) return -1;
 
@@ skipping 32 matching lines @@
     return static_cast<int32_t>(HeapNumber::cast(*result)->value());
   }
   thrower.Error("WASM.compileRun() failed: Return value should be number");
   return -1;
 }
 
 }  // namespace testing
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8