[wasm] Remove the table_object instance field

The table_object instance field is not needed anymore because its
purpose is fulfilled now by the tables field I introduced to support
multiple tables.

In addition I removed {table_instances_} from the {InstanceBuilder}.
This field existed because tables could exist without a WasmTableObject.
With recent changes, WasmTableObjects always exist.

R=mstarzinger@chromium.org

Bug: v8:7581
Change-Id: I5e8e3d2910f7ed7ae74d61eff660f9451b3493ac
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1466641
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60149}

src/objects-printer.cc

@@ -1831,8 +1831,8 @@ void WasmInstanceObject::WasmInstanceObjectPrint(std::ostream& os) {  // NOLINT
   if (has_debug_info()) {
     os << "\n - debug_info: " << Brief(debug_info());
   }
-  if (has_table_object()) {
-    os << "\n - table_object: " << Brief(table_object());
+  for (int i = 0; i < tables()->length(); i++) {
+    os << "\n - table " << i << ": " << Brief(tables()->get(i));
   }
   os << "\n - imported_function_refs: " << Brief(imported_function_refs());
   if (has_indirect_function_table_refs()) {

src/wasm/wasm-objects-inl.h

@@ -223,8 +223,6 @@ OPTIONAL_ACCESSORS(WasmInstanceObject, imported_mutable_globals_buffers,
                    FixedArray, kImportedMutableGlobalsBuffersOffset)
 OPTIONAL_ACCESSORS(WasmInstanceObject, debug_info, WasmDebugInfo,
                    kDebugInfoOffset)
-OPTIONAL_ACCESSORS(WasmInstanceObject, table_object, WasmTableObject,
-                   kTableObjectOffset)
 OPTIONAL_ACCESSORS(WasmInstanceObject, tables, FixedArray, kTablesOffset)
 ACCESSORS(WasmInstanceObject, imported_function_refs, FixedArray,
           kImportedFunctionRefsOffset)

src/wasm/wasm-objects.cc

@@ -1565,6 +1565,13 @@ bool WasmInstanceObject::CopyTableEntries(Isolate* isolate,
                                           uint32_t table_dst_index,
                                           uint32_t dst, uint32_t src,
                                           uint32_t count) {
+  if (static_cast<int>(table_dst_index) >= instance->tables()->length()) {
+    return false;
+  }
+  if (static_cast<int>(table_src_index) >= instance->tables()->length()) {
+    return false;
+  }
+
   // TODO(titzer): multiple tables in TableCopy
   CHECK_EQ(0, table_src_index);
   CHECK_EQ(0, table_dst_index);
@@ -1580,14 +1587,9 @@ bool WasmInstanceObject::CopyTableEntries(Isolate* isolate,
 
   if (dst == src || count == 0) return ok;  // no-op
 
-  if (!instance->has_table_object()) {
-    // No table object, only need to update this instance.
-    CopyTableEntriesImpl(instance, dst, src, count, copy_backward);
-    return ok;
-  }
-
-  Handle<WasmTableObject> table =
-      Handle<WasmTableObject>(instance->table_object(), isolate);
+  // TODO(titzer): multiple tables in TableCopy
+  auto table = handle(
+      WasmTableObject::cast(instance->tables()->get(table_src_index)), isolate);
   // Broadcast table copy operation to all instances that import this table.
   Handle<FixedArray> dispatch_tables(table->dispatch_tables(), isolate);
   for (int i = 0; i < dispatch_tables->length();
@@ -1600,14 +1602,18 @@ bool WasmInstanceObject::CopyTableEntries(Isolate* isolate,
   }
 
   // Copy the function entries.
-  Handle<FixedArray> functions(table->elements(), isolate);
+  auto dst_table = handle(
+      WasmTableObject::cast(instance->tables()->get(table_dst_index)), isolate);
+  auto src_table = handle(
+      WasmTableObject::cast(instance->tables()->get(table_src_index)), isolate);
   if (copy_backward) {
     for (uint32_t i = count; i > 0; i--) {
-      functions->set(dst + i - 1, functions->get(src + i - 1));
+      dst_table->elements()->set(dst + i - 1,
+                                 src_table->elements()->get(src + i - 1));
     }
   } else {
     for (uint32_t i = 0; i < count; i++) {
-      functions->set(dst + i, functions->get(src + i));
+      dst_table->elements()->set(dst + i, src_table->elements()->get(src + i));
     }
   }
   return ok;

src/wasm/wasm-objects.h

@@ -414,7 +414,6 @@ class WasmInstanceObject : public JSObject {
   DECL_OPTIONAL_ACCESSORS(tagged_globals_buffer, FixedArray)
   DECL_OPTIONAL_ACCESSORS(imported_mutable_globals_buffers, FixedArray)
   DECL_OPTIONAL_ACCESSORS(debug_info, WasmDebugInfo)
-  DECL_OPTIONAL_ACCESSORS(table_object, WasmTableObject)
   DECL_OPTIONAL_ACCESSORS(tables, FixedArray)
   DECL_ACCESSORS(imported_function_refs, FixedArray)
   DECL_OPTIONAL_ACCESSORS(indirect_function_table_refs, FixedArray)
@@ -461,7 +460,6 @@ class WasmInstanceObject : public JSObject {
   V(kTaggedGlobalsBufferOffset, kTaggedSize)                              \
   V(kImportedMutableGlobalsBuffersOffset, kTaggedSize)                    \
   V(kDebugInfoOffset, kTaggedSize)                                        \
-  V(kTableObjectOffset, kTaggedSize)                                      \
   V(kTablesOffset, kTaggedSize)                                           \
   V(kImportedFunctionRefsOffset, kTaggedSize)                             \
   V(kIndirectFunctionTableRefsOffset, kTaggedSize)                        \