[wasm] Add "freeze" flag to test lazy compilation

In order to test that we don't repeatedly go through the
WasmCompileLazy runtime function, add a flag to the
LazyCompilationOrchestrator to "freeze" it, i.e. disallow any further
lazy compilation.
In tests, use this flag to first call a method, then freeze lazy
compilation, then call the method again to assert that no further lazy
compilation is triggered.

This test currently fails with --wasm-jit-to-native, so disable it for
that variant.

R=titzer@chromium.org
CC=mtrofin@chromium.org

Bug: v8:7140, chromium:788441, v8:5991
Change-Id: I18a40d302c24041740d8a54351d06ed968f4beec
Reviewed-on: https://chromium-review.googlesource.com/796430Reviewed-by: Mircea Trofin <mtrofin@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49734}

src/runtime/runtime-test.cc

@@ -19,6 +19,7 @@
 #include "src/snapshot/natives.h"
 #include "src/trap-handler/trap-handler.h"
 #include "src/wasm/memory-tracing.h"
+#include "src/wasm/module-compiler.h"
 #include "src/wasm/wasm-module.h"
 #include "src/wasm/wasm-objects-inl.h"
 #include "src/wasm/wasm-serialization.h"
@@ -1180,5 +1181,19 @@ RUNTIME_FUNCTION(Runtime_CompleteInobjectSlackTracking) {
   return isolate->heap()->undefined_value();
 }
 
+RUNTIME_FUNCTION(Runtime_FreezeWasmLazyCompilation) {
+  DCHECK_EQ(1, args.length());
+  DisallowHeapAllocation no_gc;
+  CONVERT_ARG_CHECKED(WasmInstanceObject, instance, 0);
+
+  WasmSharedModuleData* shared = instance->compiled_module()->ptr_to_shared();
+  CHECK(shared->has_lazy_compilation_orchestrator());
+  auto* orchestrator = Managed<wasm::LazyCompilationOrchestrator>::cast(
+                           shared->lazy_compilation_orchestrator())
+                           ->get();
+  orchestrator->FreezeLazyCompilationForTesting();
+  return isolate->heap()->undefined_value();
+}
+
 }  // namespace internal
 }  // namespace v8

src/runtime/runtime.h

@@ -631,7 +631,8 @@ namespace internal {
   F(RedirectToWasmInterpreter, 2, 1)          \
   F(WasmTraceMemory, 4, 1)                    \
   F(CompleteInobjectSlackTracking, 1, 1)      \
-  F(IsLiftoffFunction, 1, 1)
+  F(IsLiftoffFunction, 1, 1)                  \
+  F(FreezeWasmLazyCompilation, 1, 1)
 
 #define FOR_EACH_INTRINSIC_TYPEDARRAY(F) \
   F(ArrayBufferGetByteLength, 1, 1)      \

src/wasm/module-compiler.cc

@@ -692,6 +692,8 @@ Handle<Code> CompileLazyOnGCHeap(Isolate* isolate) {
               ->shared()
               ->lazy_compilation_orchestrator())
           ->get();
+  DCHECK(!orchestrator->IsFrozenForTesting());
+
   Handle<Code> compiled_code = orchestrator->CompileLazyOnGCHeap(
       isolate, instance, caller_code, offset, func_index, patch_caller);
   if (!exp_deopt_data.is_null() && exp_deopt_data->length() > 2) {
@@ -779,6 +781,8 @@ Address CompileLazy(Isolate* isolate) {
       Managed<wasm::LazyCompilationOrchestrator>::cast(
           compiled_module->shared()->lazy_compilation_orchestrator())
           ->get();
+  DCHECK(!orchestrator->IsFrozenForTesting());
+
   const wasm::WasmCode* result = nullptr;
   // The caller may be js to wasm calling a function
   // also available for indirect calls.

src/wasm/module-compiler.h

@@ -95,6 +95,20 @@ class LazyCompilationOrchestrator {
   const wasm::WasmCode* CompileIndirectCall(Isolate*,
                                             Handle<WasmInstanceObject>,
                                             uint32_t func_index);
+
+#ifdef DEBUG
+  // Call this method in tests to disallow any further lazy compilation; then
+  // call into the wasm instance again to verify that no lazy compilation is
+  // triggered.
+  void FreezeLazyCompilationForTesting() { frozen_ = true; }
+  bool IsFrozenForTesting() const { return frozen_; }
+
+ private:
+  bool frozen_;
+#else
+  void FreezeLazyCompilationForTesting() {}
+  bool IsFrozenForTesting() { return false; }
+#endif
 };
 
 // Encapsulates all the state and steps of an asynchronous compilation.

test/mjsunit/mjsunit.status

@@ -706,6 +706,10 @@
   'math-*': [SKIP],
   'unicode-test': [SKIP],
   'whitespaces': [SKIP],
+
+  # Lazy compilation is currently broken for --wasm-jit-to-native
+  # (crbug.com/v8/7140).
+  'wasm/lazy-compilation': [SKIP],
 }],  # variant == wasm_traps
 
 ['variant == wasm_traps and gc_stress == True', {

test/mjsunit/wasm/lazy-compilation.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --wasm-lazy-compilation
+// Flags: --wasm-lazy-compilation --allow-natives-syntax
 
 load('test/mjsunit/wasm/wasm-constants.js');
 load('test/mjsunit/wasm/wasm-module-builder.js');
@@ -46,6 +46,10 @@ load('test/mjsunit/wasm/wasm-module-builder.js');
   instance2.exports.call_store(3);
   assertEquals(3, mem1[0]);
   assertEquals(0, mem2[0]);
+  %FreezeWasmLazyCompilation(instance1);
+  %FreezeWasmLazyCompilation(instance2);
+  instance2.exports.call_store(7);
+  assertEquals(7, mem1[0]);
 })();
 
 (function exportImportedFunction() {
@@ -60,4 +64,37 @@ load('test/mjsunit/wasm/wasm-module-builder.js');
   const instance2 = builder2.instantiate({A: instance1.exports});
 
   instance2.exports.foo();
+  %FreezeWasmLazyCompilation(instance1);
+  %FreezeWasmLazyCompilation(instance2);
+  instance2.exports.foo();
+})();
+
+(function exportImportedFunctionWithDifferentMemory() {
+  print(arguments.callee.name);
+  const builder1 = new WasmModuleBuilder();
+  builder1.addMemory(1, 1, true);
+  builder1.addFunction('store', kSig_v_i)
+      .addBody([
+        kExprI32Const, 0,        // i32.const 1
+        kExprGetLocal, 0,        // get_local 0
+        kExprI32StoreMem, 0, 0,  // i32.store offset=0 align=0
+      ])
+      .exportFunc();
+  const instance1 = builder1.instantiate();
+  const mem1 = new Int32Array(instance1.exports.memory.buffer);
+
+  const builder2 = new WasmModuleBuilder();
+  builder2.addMemory(1, 1, true);
+  const imp_idx = builder2.addImport('A', 'store', kSig_v_i);
+  builder2.addExport('exp_store', imp_idx);
+  const instance2 = builder2.instantiate({A: instance1.exports});
+  const mem2 = new Int32Array(instance2.exports.memory.buffer);
+
+  instance2.exports.exp_store(3);
+  assertEquals(3, mem1[0]);
+  assertEquals(0, mem2[0]);
+  %FreezeWasmLazyCompilation(instance1);
+  %FreezeWasmLazyCompilation(instance2);
+  instance2.exports.exp_store(7);
+  assertEquals(7, mem1[0]);
 })();