[wasm] Always provide a wasm instance object at runtime

src/wasm/wasm-objects.h

 // Copyright 2016 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_OBJECTS_H_
 #define V8_WASM_OBJECTS_H_
 
 #include "src/debug/interface-types.h"
 #include "src/objects-inl.h"
 #include "src/trap-handler/trap-handler.h"
@@ skipping 236 matching lines @@
   uint32_t default_mem_size() const;
 
   wasm::WasmModule* module() const;
 
 #define DECLARATION(KIND, TYPE, NAME) WCM_##KIND(TYPE, NAME)
   WCM_PROPERTY_TABLE(DECLARATION)
 #undef DECLARATION
 
   static bool IsWasmCompiledModule(Object* obj);
 
+  // Check whether this module wasm generated from asm.js source.
+  bool is_asm_js() const { return has_asm_js_offset_table(); }
+
   void PrintInstancesChain();
 
   static void RecreateModuleWrapper(Isolate* isolate,
                                     Handle<FixedArray> compiled_module);
 
   // Get the function name of the function identified by the given index.
   // Returns a null handle if the function is unnamed or the name is not a valid
   // UTF-8 string.
-  static MaybeHandle<String> GetFunctionName(
-      Handle<WasmCompiledModule> compiled_module, uint32_t func_index);
+  static MaybeHandle<String> GetFunctionNameOrNull(
+      Isolate* isolate, Handle<WasmCompiledModule> compiled_module,
+      uint32_t func_index);
+
+  // Get the function name of the function identified by the given index.
+  // Returns "<WASM UNNAMED>" if the function is unnamed or the name is not a
+  // valid UTF-8 string.
+  static Handle<String> GetFunctionName(
+      Isolate* isolate, Handle<WasmCompiledModule> compiled_module,
+      uint32_t func_index);
 
   // Get the raw bytes of the function name of the function identified by the
   // given index.
   // Meant to be used for debugging or frame printing.
   // Does not allocate, hence gc-safe.
   Vector<const uint8_t> GetRawFunctionName(uint32_t func_index);
 
   // Return the byte offset of the function identified by the given index.
   // The offset will be relative to the start of the module bytes.
   // Returns -1 if the function index is invalid.
@@ skipping 15 matching lines @@
                                     uint32_t func_index, uint32_t byte_offset,
                                     bool is_at_number_conversion);
 
   // Compute the disassembly of a wasm function.
   // Returns the disassembly string and a list of <byte_offset, line, column>
   // entries, mapping wasm byte offsets to line and column in the disassembly.
   // The list is guaranteed to be ordered by the byte_offset.
   // Returns an empty string and empty vector if the function index is invalid.
   debug::WasmDisassembly DisassembleFunction(int func_index);
 
+  // Extract a portion of the wire bytes as UTF-8 string.
+  // Returns a null handle if the respective bytes do not form a valid UTF-8
+  // string.
+  static MaybeHandle<String> ExtractUtf8StringFromModuleBytes(
+      Isolate* isolate, Handle<WasmCompiledModule> compiled_module,
+      uint32_t offset, uint32_t size);
+
  private:
   void InitId();
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(WasmCompiledModule);
 };
 
 // TODO(clemensh): Extend this object for breakpoint support, or remove it.
 class WasmDebugInfo : public FixedArray {
  public:
   enum class Fields { kFieldCount };
@@ skipping 61 matching lines @@
   };
 };
 
 #undef DECLARE_ACCESSORS
 #undef DECLARE_OPTIONAL_ACCESSORS
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_WASM_OBJECTS_H_