[wasm] Count calls to exported functions

This CL adds a call counter in the WasmExportedFunctionData. The counter
is incremented every time a call to an exported WebAssembly function is
handled through the generic js-to-wasm wrapper.

Bug: v8:10982
Change-Id: Iad40b414b0c7d2f4ab340ff4ebb7b24c60b3a974
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2445873
Commit-Queue: Vicky Kontoura <vkont@google.com>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70336}

src/builtins/x64/builtins-x64.cc

@@ -3362,6 +3362,14 @@ void Builtins::Generate_GenericJSToWasmWrapper(MacroAssembler* masm) {
       MemOperand(function_data,
                  WasmExportedFunctionData::kInstanceOffset - kHeapObjectTag));
 
+  // -------------------------------------------
+  // Increment the call count in function data.
+  // -------------------------------------------
+  __ SmiAddConstant(
+      MemOperand(function_data,
+                 WasmExportedFunctionData::kCallCountOffset - kHeapObjectTag),
+      Smi::FromInt(1));
+
   // -------------------------------------------
   // Load values from the signature.
   // -------------------------------------------

src/objects/shared-function-info.h

@@ -337,7 +337,8 @@ class SharedFunctionInfo : public HeapObject {
       UncompiledDataWithPreparseData data);
   inline bool HasUncompiledDataWithoutPreparseData() const;
   inline bool HasWasmExportedFunctionData() const;
-  WasmExportedFunctionData wasm_exported_function_data() const;
+  V8_EXPORT_PRIVATE WasmExportedFunctionData
+  wasm_exported_function_data() const;
   inline bool HasWasmJSFunctionData() const;
   WasmJSFunctionData wasm_js_function_data() const;
   inline bool HasWasmCapiFunctionData() const;

src/wasm/wasm-objects-inl.h

@@ -329,6 +329,7 @@ ACCESSORS(WasmExportedFunctionData, instance, WasmInstanceObject,
 SMI_ACCESSORS(WasmExportedFunctionData, jump_table_offset,
               kJumpTableOffsetOffset)
 SMI_ACCESSORS(WasmExportedFunctionData, function_index, kFunctionIndexOffset)
+SMI_ACCESSORS(WasmExportedFunctionData, call_count, kCallCountOffset)
 ACCESSORS(WasmExportedFunctionData, c_wrapper_code, Object, kCWrapperCodeOffset)
 ACCESSORS(WasmExportedFunctionData, wasm_call_target, Object,
           kWasmCallTargetOffset)

src/wasm/wasm-objects.cc

@@ -1886,6 +1886,7 @@ Handle<WasmExportedFunction> WasmExportedFunction::New(
   function_data->set_instance(*instance);
   function_data->set_jump_table_offset(jump_table_offset);
   function_data->set_function_index(func_index);
+  function_data->set_call_count(0);
   function_data->set_c_wrapper_code(Smi::zero(), SKIP_WRITE_BARRIER);
   function_data->set_wasm_call_target(Smi::zero(), SKIP_WRITE_BARRIER);
   function_data->set_packed_args_size(0);

src/wasm/wasm-objects.h

@@ -783,6 +783,7 @@ class WasmExportedFunctionData : public Struct {
   DECL_ACCESSORS(instance, WasmInstanceObject)
   DECL_INT_ACCESSORS(jump_table_offset)
   DECL_INT_ACCESSORS(function_index)
+  DECL_INT_ACCESSORS(call_count)
   DECL_ACCESSORS(c_wrapper_code, Object)
   DECL_ACCESSORS(wasm_call_target, Object)
   DECL_INT_ACCESSORS(packed_args_size)

src/wasm/wasm-objects.tq

@@ -15,6 +15,7 @@ extern class WasmExportedFunctionData extends Struct {
   instance: WasmInstanceObject;
   jump_table_offset: Smi;
   function_index: Smi;
+  call_count: Smi;
   // The remaining fields are for fast calling from C++. The contract is
   // that they are lazily populated, and either all will be present or none.
   c_wrapper_code: Object;

test/cctest/BUILD.gn

@@ -303,6 +303,7 @@ v8_source_set("cctest_sources") {
     "wasm/test-run-wasm-simd-liftoff.cc",
     "wasm/test-run-wasm-simd-scalar-lowering.cc",
     "wasm/test-run-wasm-simd.cc",
+    "wasm/test-run-wasm-wrappers.cc",
     "wasm/test-run-wasm.cc",
     "wasm/test-streaming-compilation.cc",
     "wasm/test-wasm-breakpoints.cc",

test/cctest/cctest.status

@@ -517,6 +517,7 @@
   'test-run-wasm-simd-liftoff/*': [SKIP],
   'test-run-wasm-simd-scalar-lowering/*': [SKIP],
   'test-run-wasm-simd/*': [SKIP],
+  'test-run-wasm-wrappers/*': [SKIP],
   'test-streaming-compilation/*': [SKIP],
   'test-wasm-breakpoints/*': [SKIP],
   'test-wasm-codegen/*': [SKIP],

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

@@ -0,0 +1,90 @@
+// Copyright 2020 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 "src/wasm/wasm-module-builder.h"
+#include "src/wasm/wasm-objects-inl.h"
+#include "test/cctest/cctest.h"
+#include "test/common/wasm/flag-utils.h"
+#include "test/common/wasm/test-signatures.h"
+#include "test/common/wasm/wasm-macro-gen.h"
+#include "test/common/wasm/wasm-module-runner.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+namespace test_run_wasm_wrappers {
+
+using testing::CompileAndInstantiateForTesting;
+
+#ifdef V8_TARGET_ARCH_X64
+namespace {
+void Cleanup() {
+  // By sending a low memory notifications, we will try hard to collect all
+  // garbage and will therefore also invoke all weak callbacks of actually
+  // unreachable persistent handles.
+  Isolate* isolate = CcTest::InitIsolateOnce();
+  reinterpret_cast<v8::Isolate*>(isolate)->LowMemoryNotification();
+}
+
+}  // namespace
+
+TEST(CallCounter) {
+  {
+    // This test assumes use of the generic wrapper.
+    FlagScope<bool> use_wasm_generic_wrapper(&FLAG_wasm_generic_wrapper, true);
+
+    TestSignatures sigs;
+    AccountingAllocator allocator;
+    Zone zone(&allocator, ZONE_NAME);
+
+    // Define the Wasm function.
+    WasmModuleBuilder* builder = zone.New<WasmModuleBuilder>(&zone);
+    WasmFunctionBuilder* f = builder->AddFunction(sigs.i_ii());
+    f->builder()->AddExport(CStrVector("main"), f);
+    byte code[] = {WASM_I32_MUL(WASM_GET_LOCAL(0), WASM_GET_LOCAL(1)),
+                   WASM_END};
+    f->EmitCode(code, sizeof(code));
+
+    // Compile module.
+    ZoneBuffer buffer(&zone);
+    builder->WriteTo(&buffer);
+    Isolate* isolate = CcTest::InitIsolateOnce();
+    HandleScope scope(isolate);
+    testing::SetupIsolateForWasmModule(isolate);
+    ErrorThrower thrower(isolate, "CompileAndRunWasmModule");
+    MaybeHandle<WasmInstanceObject> instance = CompileAndInstantiateForTesting(
+        isolate, &thrower, ModuleWireBytes(buffer.begin(), buffer.end()));
+
+    MaybeHandle<WasmExportedFunction> maybe_export =
+        testing::GetExportedFunction(isolate, instance.ToHandleChecked(),
+                                     "main");
+    Handle<WasmExportedFunction> main_export = maybe_export.ToHandleChecked();
+
+    // Check that the counter has initially a value of 0.
+    CHECK_EQ(main_export->shared().wasm_exported_function_data().call_count(),
+             0);
+
+    // Call the exported Wasm function and get the result.
+    Handle<Object> params[2] = {Handle<Object>(Smi::FromInt(6), isolate),
+                                Handle<Object>(Smi::FromInt(7), isolate)};
+    static const int32_t kExpectedValue = 42;
+    Handle<Object> receiver = isolate->factory()->undefined_value();
+    MaybeHandle<Object> maybe_result =
+        Execution::Call(isolate, main_export, receiver, 2, params);
+    Handle<Object> result = maybe_result.ToHandleChecked();
+
+    // Check that the counter has now a value of 1.
+    CHECK_EQ(main_export->shared().wasm_exported_function_data().call_count(),
+             1);
+
+    CHECK(result->IsSmi() && Smi::ToInt(*result) == kExpectedValue);
+  }
+  Cleanup();
+}
+#endif
+
+}  // namespace test_run_wasm_wrappers
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8