[wasm] Use WasmContext in the WasmInterpreter.

With the introduction of the WasmContext, compiled code is no longer
specialized to the memory start and size (or recently, globals_start).
This CL uses the same WasmContext between the interpreter and compiled
code, removing the need for UpdateMemory() and cached instance info.

R=clemensh@chromium.org

Bug: 
Change-Id: I0bd52352c9b6f3029246e94e239dc29f635e7920
Reviewed-on: https://chromium-review.googlesource.com/712734
Commit-Queue: Ben Titzer <titzer@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48584}

src/wasm/wasm-debug.cc

@@ -136,28 +136,12 @@ class InterpreterHandle {
     return {bytes_str->GetChars(), static_cast<size_t>(bytes_str->length())};
   }
 
-  static uint32_t GetMemSize(WasmDebugInfo* debug_info) {
-    DisallowHeapAllocation no_gc;
-    return debug_info->wasm_instance()->wasm_context()->get()->mem_size;
-  }
-
-  static byte* GetMemStart(WasmDebugInfo* debug_info) {
-    DisallowHeapAllocation no_gc;
-    return debug_info->wasm_instance()->wasm_context()->get()->mem_start;
-  }
-
-  static byte* GetGlobalsStart(WasmDebugInfo* debug_info) {
-    DisallowHeapAllocation no_gc;
-    return debug_info->wasm_instance()->wasm_context()->get()->globals_start;
-  }
-
  public:
   InterpreterHandle(Isolate* isolate, WasmDebugInfo* debug_info)
       : isolate_(isolate),
         module_(debug_info->wasm_instance()->compiled_module()->module()),
         interpreter_(isolate, module_, GetBytes(debug_info),
-                     GetGlobalsStart(debug_info), GetMemStart(debug_info),
-                     GetMemSize(debug_info)) {}
+                     debug_info->wasm_instance()->wasm_context()->get()) {}
 
   ~InterpreterHandle() { DCHECK_EQ(0, activations_.size()); }
 
@@ -422,13 +406,6 @@ class InterpreterHandle {
     return interpreter()->GetThread(0)->NumInterpretedCalls();
   }
 
-  void UpdateMemory(JSArrayBuffer* new_memory) {
-    byte* mem_start = reinterpret_cast<byte*>(new_memory->backing_store());
-    uint32_t mem_size;
-    CHECK(new_memory->byte_length()->ToUint32(&mem_size));
-    interpreter()->UpdateMemory(mem_start, mem_size);
-  }
-
   Handle<JSObject> GetGlobalScopeObject(wasm::InterpretedFrame* frame,
                                         Handle<WasmDebugInfo> debug_info) {
     Isolate* isolate = debug_info->GetIsolate();
@@ -744,12 +721,6 @@ uint64_t WasmDebugInfo::NumInterpretedCalls() {
   return handle ? handle->NumInterpretedCalls() : 0;
 }
 
-void WasmDebugInfo::UpdateMemory(JSArrayBuffer* new_memory) {
-  auto* interp_handle = GetInterpreterHandleOrNull(this);
-  if (!interp_handle) return;
-  interp_handle->UpdateMemory(new_memory);
-}
-
 // static
 Handle<JSObject> WasmDebugInfo::GetScopeDetails(
     Handle<WasmDebugInfo> debug_info, Address frame_pointer, int frame_index) {

src/wasm/wasm-interpreter.h

@@ -16,6 +16,7 @@ class AccountingAllocator;
 
 namespace internal {
 class WasmInstanceObject;
+struct WasmContext;
 
 namespace wasm {
 
@@ -172,8 +173,7 @@ class V8_EXPORT_PRIVATE WasmInterpreter {
   };
 
   WasmInterpreter(Isolate* isolate, const WasmModule* module,
-                  const ModuleWireBytes& wire_bytes, byte* globals_start,
-                  byte* mem_start, uint32_t mem_size);
+                  const ModuleWireBytes& wire_bytes, WasmContext* wasm_context);
   ~WasmInterpreter();
 
   //==========================================================================
@@ -198,11 +198,6 @@ class V8_EXPORT_PRIVATE WasmInterpreter {
   int GetThreadCount();
   Thread* GetThread(int id);
 
-  //==========================================================================
-  // Update the cached module env memory parameters after a grow memory event.
-  //==========================================================================
-  void UpdateMemory(byte* mem_start, uint32_t mem_size);
-
   //==========================================================================
   // Testing functionality.
   //==========================================================================

src/wasm/wasm-objects.cc

@@ -368,9 +368,6 @@ Handle<JSArrayBuffer> GrowMemoryBuffer(Isolate* isolate,
 void SetInstanceMemory(Isolate* isolate, Handle<WasmInstanceObject> instance,
                        Handle<JSArrayBuffer> buffer) {
   instance->set_memory_buffer(*buffer);
-  if (instance->has_debug_info()) {
-    instance->debug_info()->UpdateMemory(*buffer);
-  }
   auto wasm_context = instance->wasm_context()->get();
   wasm_context->mem_start = reinterpret_cast<byte*>(buffer->backing_store());
   wasm_context->mem_size = buffer->byte_length()->Number();

src/wasm/wasm-objects.h

@@ -632,10 +632,6 @@ class WasmDebugInfo : public FixedArray {
   // Returns the number of calls / function frames executed in the interpreter.
   uint64_t NumInterpretedCalls();
 
-  // Update the memory view of the interpreter after executing GrowMemory in
-  // compiled code.
-  void UpdateMemory(JSArrayBuffer* new_memory);
-
   // Get scope details for a specific interpreted frame.
   // This returns a JSArray of length two: One entry for the global scope, one
   // for the local scope. Both elements are JSArrays of size

test/cctest/wasm/wasm-run-utils.cc

@@ -53,9 +53,6 @@ byte* TestingModuleBuilder::AddMemory(uint32_t size) {
   CHECK(size == 0 || mem_start_);
   memset(mem_start_, 0, size);
 
-  if (interpreter_) {
-    interpreter_->UpdateMemory(mem_start_, mem_size_);
-  }
   // Create the WasmMemoryObject.
   Handle<WasmMemoryObject> memory_object = WasmMemoryObject::New(
       isolate_, new_buffer,