Remove usage of CHECK_NOTNULL

We want to switch to absl logging instead of glog.  gtest and ceres are
going there, and we already have absl as a dependency.  ABSL doesn't
have CHECK_NOTNULL, and we can move things over in an easier to review
fashion.

Change-Id: Ifd9a11ec34a2357cec43f88dba015db9c28ed2cf
Signed-off-by: Austin Schuh <austin.linux@gmail.com>
diff --git a/y2024/autonomous/autonomous_actor.cc b/y2024/autonomous/autonomous_actor.cc
index 0f70292..83cf5b1 100644
--- a/y2024/autonomous/autonomous_actor.cc
+++ b/y2024/autonomous/autonomous_actor.cc
@@ -51,8 +51,10 @@
           event_loop
               ->MakeFetcher<::y2024::control_loops::superstructure::Status>(
                   "/superstructure")),
-      robot_constants_(CHECK_NOTNULL(robot_constants)),
-      auto_splines_() {}
+      robot_constants_(robot_constants),
+      auto_splines_() {
+  CHECK(robot_constants_ != nullptr);
+}
 
 void AutonomousActor::Replan() {
   AutonomousMode mode = robot_constants_->common()->autonomous_mode();
diff --git a/y2024/control_loops/drivetrain/drivetrain_base.cc b/y2024/control_loops/drivetrain/drivetrain_base.cc
index 79d35e1..dd4f33c 100644
--- a/y2024/control_loops/drivetrain/drivetrain_base.cc
+++ b/y2024/control_loops/drivetrain/drivetrain_base.cc
@@ -11,9 +11,10 @@
 const frc971::control_loops::drivetrain::DrivetrainConfig<double>
 GetDrivetrainConfig(aos::EventLoop *event_loop) {
   frc971::constants::ConstantsFetcher<Constants> constants_fetcher(event_loop);
+  CHECK(constants_fetcher.constants().common() != nullptr);
+  CHECK(constants_fetcher.constants().common()->drivetrain() != nullptr);
   return frc971::control_loops::drivetrain::DrivetrainConfig<double>::
-      FromFlatbuffer(
-          *CHECK_NOTNULL(constants_fetcher.constants().common()->drivetrain()));
+      FromFlatbuffer(*constants_fetcher.constants().common()->drivetrain());
 };
 
 }  // namespace y2024::control_loops::drivetrain
diff --git a/y2024/control_loops/superstructure/aiming.cc b/y2024/control_loops/superstructure/aiming.cc
index d8d336f..b53dbb5 100644
--- a/y2024/control_loops/superstructure/aiming.cc
+++ b/y2024/control_loops/superstructure/aiming.cc
@@ -11,7 +11,10 @@
 Aimer::Aimer(aos::EventLoop *event_loop,
              const y2024::Constants *robot_constants)
     : event_loop_(event_loop),
-      robot_constants_(CHECK_NOTNULL(robot_constants)),
+      robot_constants_([&]() {
+        CHECK(robot_constants != nullptr);
+        return robot_constants;
+      }()),
       drivetrain_config_(
           frc971::control_loops::drivetrain::DrivetrainConfig<double>::
               FromFlatbuffer(*robot_constants_->common()->drivetrain())),
@@ -58,7 +61,7 @@
   } else {
     received_joystick_state_ = true;
 
-    CHECK_NOTNULL(joystick_state_fetcher_.get());
+    CHECK(joystick_state_fetcher_.get() != nullptr);
     alliance = joystick_state_fetcher_->alliance();
   }
 
diff --git a/y2024/control_loops/superstructure/superstructure.cc b/y2024/control_loops/superstructure/superstructure.cc
index a485943..7f7da4f 100644
--- a/y2024/control_loops/superstructure/superstructure.cc
+++ b/y2024/control_loops/superstructure/superstructure.cc
@@ -36,7 +36,7 @@
     : frc971::controls::ControlLoop<Goal, Position, Status, Output>(event_loop,
                                                                     name),
       constants_fetcher_(event_loop),
-      robot_constants_(CHECK_NOTNULL(&constants_fetcher_.constants())),
+      robot_constants_(&constants_fetcher_.constants()),
       drivetrain_status_fetcher_(
           event_loop->MakeFetcher<frc971::control_loops::drivetrain::Status>(
               "/drivetrain")),
diff --git a/y2024/control_loops/superstructure/superstructure_lib_test.cc b/y2024/control_loops/superstructure/superstructure_lib_test.cc
index 59398ab..719a29b 100644
--- a/y2024/control_loops/superstructure/superstructure_lib_test.cc
+++ b/y2024/control_loops/superstructure/superstructure_lib_test.cc
@@ -312,8 +312,7 @@
         superstructure_(superstructure_event_loop.get()),
         test_event_loop_(MakeEventLoop("test", roborio_)),
         constants_fetcher_(test_event_loop_.get()),
-        simulated_robot_constants_(
-            CHECK_NOTNULL(&constants_fetcher_.constants())),
+        simulated_robot_constants_(&constants_fetcher_.constants()),
         superstructure_goal_fetcher_(
             test_event_loop_->MakeFetcher<Goal>("/superstructure")),
         superstructure_goal_sender_(
diff --git a/y2024/joystick_reader.cc b/y2024/joystick_reader.cc
index 711f9d2..88bf441 100644
--- a/y2024/joystick_reader.cc
+++ b/y2024/joystick_reader.cc
@@ -82,7 +82,9 @@
         superstructure_status_fetcher_(
             event_loop->MakeFetcher<control_loops::superstructure::Status>(
                 "/superstructure")),
-        robot_constants_(CHECK_NOTNULL(robot_constants)) {}
+        robot_constants_(robot_constants) {
+    CHECK(robot_constants_ != nullptr);
+  }
 
   void AutoEnded() override { AOS_LOG(INFO, "Auto ended.\n"); }
 
diff --git a/y2024/localizer/localizer.cc b/y2024/localizer/localizer.cc
index d73d171..90423ca 100644
--- a/y2024/localizer/localizer.cc
+++ b/y2024/localizer/localizer.cc
@@ -174,10 +174,12 @@
 Localizer::Localizer(aos::EventLoop *event_loop)
     : event_loop_(event_loop),
       constants_fetcher_(event_loop),
-      dt_config_(
-          frc971::control_loops::drivetrain::DrivetrainConfig<double>::
-              FromFlatbuffer(*CHECK_NOTNULL(
-                  constants_fetcher_.constants().common()->drivetrain()))),
+      dt_config_(frc971::control_loops::drivetrain::DrivetrainConfig<
+                 double>::FromFlatbuffer(*[&]() {
+        CHECK(constants_fetcher_.constants().common() != nullptr);
+        CHECK(constants_fetcher_.constants().common()->drivetrain() != nullptr);
+        return constants_fetcher_.constants().common()->drivetrain();
+      }())),
       cameras_(MakeCameras(constants_fetcher_.constants(), event_loop)),
       target_poses_(GetTargetLocations(constants_fetcher_.constants())),
       down_estimator_(dt_config_),
@@ -214,8 +216,9 @@
 
   for (size_t camera_index = 0; camera_index < kNumCameras; ++camera_index) {
     const std::string_view channel_name = kDetectionChannels.at(camera_index);
-    const aos::Channel *const channel = CHECK_NOTNULL(
-        event_loop->GetChannel<frc971::vision::TargetMap>(channel_name));
+    const aos::Channel *const channel =
+        event_loop->GetChannel<frc971::vision::TargetMap>(channel_name);
+    CHECK(channel != nullptr);
     event_loop->MakeWatcher(
         channel_name, [this, channel,
                        camera_index](const frc971::vision::TargetMap &targets) {
@@ -360,12 +363,14 @@
 
   switch (utils_.Alliance()) {
     case aos::Alliance::kRed:
-      ignore_tags = CHECK_NOTNULL(
-          constants_fetcher_.constants().common()->ignore_targets()->red());
+      ignore_tags =
+          constants_fetcher_.constants().common()->ignore_targets()->red();
+      CHECK(ignore_tags != nullptr);
       break;
     case aos::Alliance::kBlue:
-      ignore_tags = CHECK_NOTNULL(
-          constants_fetcher_.constants().common()->ignore_targets()->blue());
+      ignore_tags =
+          constants_fetcher_.constants().common()->ignore_targets()->blue();
+      CHECK(ignore_tags != nullptr);
       break;
     case aos::Alliance::kInvalid:
       return false;
diff --git a/y2024/wpilib_interface.cc b/y2024/wpilib_interface.cc
index 30d1549..c8328da 100644
--- a/y2024/wpilib_interface.cc
+++ b/y2024/wpilib_interface.cc
@@ -123,7 +123,7 @@
   SensorReader(::aos::ShmEventLoop *event_loop,
                const Constants *robot_constants)
       : ::frc971::wpilib::SensorReader(event_loop),
-        robot_constants_(CHECK_NOTNULL(robot_constants)),
+        robot_constants_(robot_constants),
         auto_mode_sender_(
             event_loop->MakeSender<::frc971::autonomous::AutonomousMode>(
                 "/autonomous")),
@@ -505,7 +505,8 @@
                     drivetrain_can_position_sender.MakeStaticBuilder();
 
             auto drivetrain_falcon_vector =
-                CHECK_NOTNULL(drivetrain_can_builder->add_talonfxs());
+                drivetrain_can_builder->add_talonfxs();
+            CHECK(drivetrain_falcon_vector != nullptr);
 
             for (auto talonfx : drivetrain_krakens) {
               talonfx->SerializePosition(
@@ -678,7 +679,8 @@
                   drivetrain_can_position_sender.MakeStaticBuilder();
 
           auto drivetrain_falcon_vector =
-              CHECK_NOTNULL(drivetrain_can_builder->add_talonfxs());
+              drivetrain_can_builder->add_talonfxs();
+          CHECK(drivetrain_falcon_vector != nullptr);
 
           for (auto talonfx : drivetrain_talonfxs) {
             talonfx->SerializePosition(