[wasm] Only use the table maximum in allocation if it is non-zero.

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 <memory>
 
 #include "src/base/atomic-utils.h"
 #include "src/code-stubs.h"
 
 #include "src/macro-assembler.h"
@@ skipping 1024 matching lines @@
     //--------------------------------------------------------------------------
     int function_table_count =
         static_cast<int>(module_->function_tables.size());
     if (function_table_count > 0) {
       Handle<FixedArray> old_function_tables =
           compiled_module_->function_tables();
       Handle<FixedArray> new_function_tables =
           factory->NewFixedArray(function_table_count);
       for (int index = 0; index < function_table_count; ++index) {
         WasmIndirectFunctionTable& table = module_->function_tables[index];
-        uint32_t size = table.max_size;
+        uint32_t size = table.max_size > 0 ? table.max_size : table.size;

[ahaas, 2016/10/20 09:09:42]

Could we just set the default value of table.max_size to kMaxTableSize instead
of setting it to 0?

         Handle<FixedArray> new_table = factory->NewFixedArray(size * 2);
         for (int i = 0; i < new_table->length(); ++i) {
           static const int kInvalidSigIndex = -1;
           // Fill the table with invalid signature indexes so that uninitialized
           // entries will always fail the signature check.
           new_table->set(i, Smi::FromInt(kInvalidSigIndex));
         }
         for (auto table_init : module_->table_inits) {
           uint32_t base = EvalUint32InitExpr(globals, table_init.offset);
           uint32_t table_size = static_cast<uint32_t>(new_table->length());
@@ skipping 925 matching lines @@
     CHECK_NOT_NULL(result.val);
     module = const_cast<WasmModule*>(result.val);
   }
 
   Handle<WasmModuleWrapper> module_wrapper =
       WasmModuleWrapper::New(isolate, module);
 
   compiled_module->set_module_wrapper(module_wrapper);
   DCHECK(WasmCompiledModule::IsWasmCompiledModule(*compiled_module));
 }