[wasm][debug] Pass pointer for detected features

We currently hit a nullptr access when trying to update the detected
feature set. Instead of adding a check for nullptr there (which would be
unnecessary overhead in production code), we just pass a pointer when
compiling for debugging.

R=thibaudm@chromium.org

Bug: chromium:1092408
Change-Id: I7804edc3f67237bbf28d0ed2f5c58339d3a0f8f7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2238080Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68335}

src/wasm/wasm-debug.cc

@@ -415,9 +415,11 @@ class DebugInfoImpl {
 
     ForDebugging for_debugging =
         offsets.size() == 1 && offsets[0] == 0 ? kForStepping : kForDebugging;
+    Counters* counters = nullptr;
+    WasmFeatures unused_detected;
     WasmCompilationResult result = ExecuteLiftoffCompilation(
         native_module_->engine()->allocator(), &env, body, func_index,
-        for_debugging, nullptr, nullptr, offsets, &debug_sidetable,
+        for_debugging, counters, &unused_detected, offsets, &debug_sidetable,
         extra_source_positions);
     // Liftoff compilation failure is a FATAL error. We rely on complete Liftoff
     // support for debugging.

test/cctest/wasm/test-wasm-breakpoints.cc

@@ -541,6 +541,39 @@ WASM_COMPILED_EXEC_TEST(WasmRemoveAllBreakPoint) {
   CHECK_EQ(14, GetIntReturnValue(retval));
 }
 
+WASM_COMPILED_EXEC_TEST(WasmBreakInPostMVP) {
+  // This test checks that we don't fail if experimental / post-MVP opcodes are
+  // being used. There was a bug where we were trying to update the "detected"
+  // features set, but we were passing a nullptr when compiling with
+  // breakpoints.
+  EXPERIMENTAL_FLAG_SCOPE(mv);
+  WasmRunner<int> runner(execution_tier);
+  Isolate* isolate = runner.main_isolate();
+
+  // [] -> [i32, i32]
+  ValueType sig_types[] = {kWasmI32, kWasmI32};
+  FunctionSig sig{2, 0, sig_types};
+  uint8_t sig_idx = runner.builder().AddSignature(&sig);
+
+  constexpr int kReturn = 13;
+  constexpr int kIgnored = 23;
+  BUILD(runner,
+        WASM_BLOCK_X(sig_idx, WASM_I32V_1(kReturn), WASM_I32V_1(kIgnored)),
+        WASM_DROP);
+
+  Handle<JSFunction> main_fun_wrapper =
+      runner.builder().WrapCode(runner.function_index());
+
+  SetBreakpoint(&runner, runner.function_index(), 3, 3);
+
+  BreakHandler count_breaks(isolate, {{3, BreakHandler::Continue}});
+
+  Handle<Object> global(isolate->context().global_object(), isolate);
+  MaybeHandle<Object> retval =
+      Execution::Call(isolate, main_fun_wrapper, global, 0, nullptr);
+  CHECK_EQ(kReturn, GetIntReturnValue(retval));
+}
+
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8