Enable lazy-async-stacks by-default in all modes (Take 4) (#21802)

Author: Clement Skau

runtime/dart_vm.cc

@@ -59,7 +59,8 @@ static const char* kDartLanguageArgs[] = {
     // clang-format off
     "--enable_mirrors=false",
     "--background_compilation",
-    "--causal_async_stacks",
+    "--no-causal_async_stacks",
+    "--lazy_async_stacks",
     // clang-format on
 };
 

shell/common/shell_unittests.cc

@@ -316,6 +316,8 @@ TEST_F(ShellTest, AllowedDartVMFlag) {
   std::vector<const char*> flags = {
       "--enable-isolate-groups",
       "--no-enable-isolate-groups",
+      "--lazy_async_stacks",
+      "--no-causal_async_stacks",
   };
 #if !FLUTTER_RELEASE
   flags.push_back("--max_profile_depth 1");

shell/platform/fuchsia/dart_runner/dart_runner.cc

@@ -36,9 +36,8 @@ namespace {
 
 const char* kDartVMArgs[] = {
     // clang-format off
-    // TODO(FL-117): Re-enable causal async stack traces when this issue is
-    // addressed.
     "--no_causal_async_stacks",
+    "--lazy_async_stacks",
 
     "--systrace_timeline",
     "--timeline_streams=Compiler,Dart,Debugger,Embedder,GC,Isolate,VM",

shell/platform/fuchsia/dart_runner/embedder/BUILD.gn

@@ -47,6 +47,7 @@ template("create_aot_snapshot") {
 
     args = [
       "--no_causal_async_stacks",
+      "--lazy_async_stacks",
       "--deterministic",
       "--snapshot_kind=vm-aot-assembly",
       "--assembly=" + rebase_path(snapshot_assembly),

shell/platform/fuchsia/dart_runner/kernel/BUILD.gn

@@ -68,9 +68,8 @@ template("create_kernel_core_snapshot") {
     tool = gen_snapshot_to_use
 
     args = [
-      # TODO(FL-117): Re-enable causal async stack traces when this issue is
-      # addressed.
       "--no_causal_async_stacks",
+      "--lazy_async_stacks",
       "--enable_mirrors=false",
       "--deterministic",
       "--snapshot_kind=core-jit",

shell/platform/fuchsia/dart_runner/vmservice/BUILD.gn

@@ -58,6 +58,7 @@ template("aot_snapshot") {
 
     args = [
       "--no_causal_async_stacks",
+      "--lazy_async_stacks",
       "--deterministic",
       "--snapshot_kind=app-aot-elf",
       "--elf=" + rebase_path(snapshot_path),

shell/platform/fuchsia/flutter/component.cc

@@ -402,9 +402,7 @@ Application::Application(
   settings_.task_observer_remove = std::bind(
       &CurrentMessageLoopRemoveAfterTaskObserver, std::placeholders::_1);
 
-  // TODO(FL-117): Re-enable causal async stack traces when this issue is
-  // addressed.
-  settings_.dart_flags = {"--no_causal_async_stacks"};
+  settings_.dart_flags = {"--no_causal_async_stacks", "--lazy_async_stacks"};
 
   // Don't collect CPU samples from Dart VM C++ code.
   settings_.dart_flags.push_back("--no_profile_vm");

shell/platform/fuchsia/flutter/kernel/BUILD.gn

@@ -72,9 +72,8 @@ template("core_snapshot") {
     tool = gen_snapshot_to_use
 
     args = [
-      # TODO(FL-117): Re-enable causal async stack traces when this issue is
-      # addressed.
       "--no_causal_async_stacks",
+      "--lazy_async_stacks",
       "--enable_mirrors=false",
       "--deterministic",
       "--snapshot_kind=core-jit",

testing/scenario_app/compile_ios_jit.sh

@@ -74,7 +74,8 @@ echo "Compiling JIT Snapshot..."
 
 "$DEVICE_TOOLS/gen_snapshot" --deterministic \
   --enable-asserts \
-  --causal_async_stacks \
+  --no-causal_async_stacks \
+  --lazy_async_stacks \
   --isolate_snapshot_instructions="$OUTDIR/isolate_snapshot_instr" \
   --snapshot_kind=app-jit \
   --load_vm_snapshot_data="$DEVICE_TOOLS/../gen/flutter/lib/snapshot/vm_isolate_snapshot.bin" \

testing/testing.gni

@@ -129,7 +129,8 @@ template("dart_snapshot_aot") {
     outputs = [ elf_object ]
 
     args = [
-      "--causal_async_stacks",
+      "--no-causal_async_stacks",
+      "--lazy_async_stacks",
       "--deterministic",
       "--snapshot_kind=app-aot-elf",
       "--elf=" + rebase_path(elf_object),