[wasm] Add functionality to decode a function offset table

src/wasm/wasm-module.h

 // 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.
 
 #ifndef V8_WASM_MODULE_H_
 #define V8_WASM_MODULE_H_
 
 #include "src/api.h"
 #include "src/handles.h"
 #include "src/wasm/wasm-opcodes.h"
@@ skipping 287 matching lines @@
   const WasmFunction* function_;
   const WasmModule* module_;
   WasmFunctionName(const WasmFunction* function, const ModuleEnv* menv)
       : function_(function), module_(menv ? menv->module : nullptr) {}
 };
 
 std::ostream& operator<<(std::ostream& os, const WasmModule& module);
 std::ostream& operator<<(std::ostream& os, const WasmFunction& function);
 std::ostream& operator<<(std::ostream& os, const WasmFunctionName& name);
 
-typedef Result<const WasmModule*> ModuleResult;
-typedef Result<WasmFunction*> FunctionResult;
+using ModuleResult = Result<const WasmModule*>;

[titzer, 2016/06/10 11:20:05]

You can just use a typedef for these, since they are semantically equivalent.
IIUC, this using syntax is only useful when template typedefs are involved.

Let's stick with typedef and if we want to use the "using" syntax, update all of
them at the same time.

[Clemens Hammacher, 2016/06/16 08:14:18]

Done.

+using FunctionResult = Result<WasmFunction*>;
+using FunctionOffsets = std::vector<std::pair<int, int>>;
+using FunctionOffsetsResult = Result<FunctionOffsets>;
 
 // For testing. Decode, verify, and run the last exported function in the
 // given encoded module.
 int32_t CompileAndRunWasmModule(Isolate* isolate, const byte* module_start,
                                 const byte* module_end, bool asm_js = false);
 
 // For testing. Decode, verify, and run the last exported function in the
 // given decoded module.
 int32_t CompileAndRunWasmModule(Isolate* isolate, const WasmModule* module);
 
@@ skipping 14 matching lines @@
 // secure. If it turns out that we need more complete checks, we could add a
 // special marker as internal field, which will definitely never occur anywhere
 // else.
 bool IsWasmObject(Handle<JSObject> object);
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_WASM_MODULE_H_