[wasm] Dont compute global offsets if the module had errors (e.g. invalid memory type for global).

test/unittests/wasm/module-decoder-unittest.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 "test/unittests/test-utils.h"
 
 #include "src/wasm/module-decoder.h"
 #include "src/wasm/wasm-macro-gen.h"
 #include "src/wasm/wasm-opcodes.h"
 
@@ skipping 183 matching lines @@
     EXPECT_EQ(MachineType::Int32(), global->type);
     EXPECT_EQ(0, global->offset);
     EXPECT_FALSE(global->exported);
 
     if (result.val) delete result.val;
   }
 
   EXPECT_OFF_END_FAILURE(data, 1, sizeof(data));
 }
 
+TEST_F(WasmModuleVerifyTest, Global_invalid_type) {
+  static const byte data[] = {

[ahaas, 2016/06/07 09:04:42]

Could you add a comment which says why this data is invalid?

+      SECTION(GLOBALS, 5),  // --
+      1,
+      NAME_LENGTH(1),
+      'g',  // name
+      64,   // memory type
+      0,    // exported
+  };
+
+  ModuleResult result = DecodeModuleNoHeader(data, data + sizeof(data));
+  EXPECT_FALSE(result.ok());
+  if (result.val) delete result.val;
+}
+
 TEST_F(WasmModuleVerifyTest, ZeroGlobals) {
   static const byte data[] = {
       SECTION(GLOBALS, 1),  // --
       0,                    // declare 0 globals
   };
   ModuleResult result = DecodeModule(data, data + arraysize(data));
   EXPECT_OK(result);
   if (result.val) delete result.val;
 }
 
@@ skipping 971 matching lines @@
       NO_LOCAL_NAMES,  // --
       FOO_STRING,
       NO_LOCAL_NAMES,  // --
   };
   EXPECT_VERIFIES(data);
 }
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8