refactor(container): lazily-load Vector_Instrumentation

Some global objects, such as Configuration objects in tests, want to
use Vector. However, they cannot use Vector because, in instrumented
builds, Instrumented_Vector<>'s constructor appends data to
Vector_Instrumentation and the initialization order is not guaranteed
(thus Vector_Instrumentation could be initialized *after* the
Instrumented_Vector<>.)

Fix the initialization order problem by lazily-loading the
Vector_Instrumentation singleton.

Deinitialization order is still a problem and will be fixed in a
future commit.

src/quick-lint-js/container/vector-profiler.cpp

@@ -23,7 +23,10 @@ QLJS_WARNING_IGNORE_MSVC(4996)  // Function or variable may be unsafe.
 
 namespace quick_lint_js {
 #if QLJS_FEATURE_VECTOR_PROFILING
-Vector_Instrumentation Vector_Instrumentation::instance;
+Vector_Instrumentation &Vector_Instrumentation::instance() {
+  static Vector_Instrumentation instrumentation;
+  return instrumentation;
+}
 #endif
 
 void Vector_Instrumentation::clear() { this->entries_.lock()->clear(); }
@@ -68,7 +71,7 @@ void Vector_Instrumentation::register_dump_on_exit_if_requested() {
     (void)File_Output_Stream::get_stderr();
 
     std::atexit([]() -> void {
-      auto entries = instance.entries();
+      auto entries = instance().entries();
       Output_Stream &out = *File_Output_Stream::get_stderr();
 
       {

src/quick-lint-js/container/vector-profiler.h

@@ -52,7 +52,7 @@ class Vector_Instrumentation {
   };
 
 #if QLJS_FEATURE_VECTOR_PROFILING
-  static Vector_Instrumentation instance;
+  static Vector_Instrumentation &instance();
 #endif
 
   void clear();
@@ -366,7 +366,7 @@ class Instrumented_Vector {
  private:
   QLJS_FORCE_INLINE void add_instrumentation_entry(
       Vector_Instrumentation::Event event) {
-    Vector_Instrumentation::instance.add_entry(
+    Vector_Instrumentation::instance().add_entry(
         /*object_id=*/reinterpret_cast<std::uintptr_t>(this),
         /*owner=*/this->debug_owner_,
         /*event=*/event,

src/quick-lint-js/debug/debug-server.cpp

@@ -356,7 +356,7 @@ void Debug_Server::wakeup_pipe_callback(::mg_connection *c, int ev, void *) {
       this->need_publish_vector_profile_.store(false);
 
       this->max_size_histogram_.add_entries(
-          Vector_Instrumentation::instance.take_entries());
+          Vector_Instrumentation::instance().take_entries());
 
       Trace_Writer *tw =
           Trace_Flusher::instance()->trace_writer_for_current_thread();

test/test-debug-server.cpp

@@ -164,7 +164,7 @@ TEST_F(Test_Debug_Server, two_servers_listening_on_same_port_fails) {
 #if QLJS_FEATURE_VECTOR_PROFILING
 TEST_F(Test_Debug_Server,
        web_socket_publishes_vector_profile_stats_on_connect) {
-  Vector_Instrumentation::instance.clear();
+  Vector_Instrumentation::instance().clear();
   {
     Instrumented_Vector<std::vector<int>> v("debug server test vector", {});
     ASSERT_EQ(v.size(), 0);
@@ -218,7 +218,7 @@ TEST_F(Test_Debug_Server,
 }
 
 TEST_F(Test_Debug_Server, vector_profile_probe_publishes_stats) {
-  Vector_Instrumentation::instance.clear();
+  Vector_Instrumentation::instance().clear();
 
   bool received_vector_max_size_histogram_by_owner_event = false;
   auto on_trace_event =

test/test-vector-profiler.cpp

@@ -40,7 +40,7 @@ using Test_Vector = Instrumented_Vector<std::vector<int>>;
 
 class Test_Instrumented_Vector : public ::testing::Test {
  public:
-  void SetUp() override { Vector_Instrumentation::instance.clear(); }
+  void SetUp() override { Vector_Instrumentation::instance().clear(); }
 };
 
 TEST_F(Test_Instrumented_Vector,
@@ -53,7 +53,7 @@ TEST_F(Test_Instrumented_Vector,
   }
 
   EXPECT_THAT(
-      Vector_Instrumentation::instance.take_entries(),
+      Vector_Instrumentation::instance().take_entries(),
       ElementsAre(
           AllOf(FIELD_EQ(Vector_Instrumentation::Entry, object_id, v_object_id),
                 FIELD_EQ(Vector_Instrumentation::Entry, owner, owner),
@@ -74,7 +74,7 @@ TEST_F(Test_Instrumented_Vector, creating_vector_from_range_adds_entry) {
 
   std::uintptr_t v_object_id = reinterpret_cast<std::uintptr_t>(&v);
   EXPECT_THAT(
-      Vector_Instrumentation::instance.take_entries(),
+      Vector_Instrumentation::instance().take_entries(),
       ElementsAreArray({
           AllOf(FIELD_EQ(Vector_Instrumentation::Entry, object_id, v_object_id),
                 FIELD_EQ(Vector_Instrumentation::Entry, owner, owner),
@@ -87,15 +87,15 @@ TEST_F(Test_Instrumented_Vector, creating_vector_from_range_adds_entry) {
 
 TEST_F(Test_Instrumented_Vector, append_to_vector_adds_entries) {
   Test_Vector<int> v("test vector", {});
-  Vector_Instrumentation::instance.clear();
+  Vector_Instrumentation::instance().clear();
 
   v.emplace_back(100);
   v.emplace_back(200);
   v.emplace_back(300);
   v.emplace_back(400);
 
   EXPECT_THAT(
-      Vector_Instrumentation::instance.take_entries(),
+      Vector_Instrumentation::instance().take_entries(),
       ElementsAre(AllOf(FIELD_EQ(Vector_Instrumentation::Entry, event,
                                  Vector_Instrumentation::Event::append),
                         FIELD_EQ(Vector_Instrumentation::Entry, size, 1)),
@@ -114,11 +114,11 @@ TEST_F(Test_Instrumented_Vector, clearing_vector_adds_entry) {
   Test_Vector<int> v("test vector", {});
   v.emplace_back(100);
   v.emplace_back(200);
-  Vector_Instrumentation::instance.clear();
+  Vector_Instrumentation::instance().clear();
 
   v.clear();
 
-  EXPECT_THAT(Vector_Instrumentation::instance.take_entries(),
+  EXPECT_THAT(Vector_Instrumentation::instance().take_entries(),
               ElementsAreArray({
                   AllOf(FIELD_EQ(Vector_Instrumentation::Entry, event,
                                  Vector_Instrumentation::Event::clear),
@@ -132,14 +132,14 @@ TEST_F(Test_Instrumented_Vector, moving_vector_with_new_owner_adds_entries) {
   std::uintptr_t v_1_object_id = reinterpret_cast<std::uintptr_t>(&v_1);
   v_1.emplace_back(100);
   v_1.emplace_back(200);
-  Vector_Instrumentation::instance.clear();
+  Vector_Instrumentation::instance().clear();
 
   const char *v_2_owner = "v2";
   Test_Vector<int> v_2(v_2_owner, std::move(v_1));
   std::uintptr_t v_2_object_id = reinterpret_cast<std::uintptr_t>(&v_2);
 
   EXPECT_THAT(
-      Vector_Instrumentation::instance.take_entries(),
+      Vector_Instrumentation::instance().take_entries(),
       ElementsAre(
           AllOf(
               FIELD_EQ(Vector_Instrumentation::Entry, owner, v_2_owner),
@@ -161,13 +161,13 @@ TEST_F(Test_Instrumented_Vector, moving_vector_with_no_owner_adds_entries) {
   std::uintptr_t v_1_object_id = reinterpret_cast<std::uintptr_t>(&v_1);
   v_1.emplace_back(100);
   v_1.emplace_back(200);
-  Vector_Instrumentation::instance.clear();
+  Vector_Instrumentation::instance().clear();
 
   Test_Vector<int> v_2(std::move(v_1));
   std::uintptr_t v_2_object_id = reinterpret_cast<std::uintptr_t>(&v_2);
 
   EXPECT_THAT(
-      Vector_Instrumentation::instance.take_entries(),
+      Vector_Instrumentation::instance().take_entries(),
       ElementsAre(
           AllOf(
               FIELD_EQ(Vector_Instrumentation::Entry, owner, v_1_owner),
@@ -193,12 +193,12 @@ TEST_F(Test_Instrumented_Vector, move_assigning_vector_adds_entries) {
   v_2.emplace_back(200);
   v_2.emplace_back(300);
   std::uintptr_t v_2_object_id = reinterpret_cast<std::uintptr_t>(&v_2);
-  Vector_Instrumentation::instance.clear();
+  Vector_Instrumentation::instance().clear();
 
   v_1 = std::move(v_2);
 
   EXPECT_THAT(
-      Vector_Instrumentation::instance.take_entries(),
+      Vector_Instrumentation::instance().take_entries(),
       ElementsAre(
           AllOf(
               FIELD_EQ(Vector_Instrumentation::Entry, owner, v_1_owner),