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/y2023/control_loops/drivetrain/target_selector.cc b/y2023/control_loops/drivetrain/target_selector.cc
index bc1fb90..22a5140 100644
--- a/y2023/control_loops/drivetrain/target_selector.cc
+++ b/y2023/control_loops/drivetrain/target_selector.cc
@@ -78,7 +78,7 @@
       [possible_grids, hint]() {
         aos::SizedArray<const localizer::ScoringRow *, 3> rows;
         for (const localizer::ScoringGrid *grid : possible_grids) {
-          CHECK_NOTNULL(grid);
+          CHECK(grid != nullptr);
           switch (hint->row()) {
             case RowSelectionHint::BOTTOM:
               rows.push_back(grid->bottom());
@@ -95,7 +95,7 @@
       }();
   aos::SizedArray<const frc971::vision::Position *, 3> positions;
   for (const localizer::ScoringRow *row : possible_rows) {
-    CHECK_NOTNULL(row);
+    CHECK(row != nullptr);
     switch (hint->spot()) {
       case SpotSelectionHint::LEFT:
         positions.push_back(row->left_cone());
diff --git a/y2023/control_loops/superstructure/superstructure.cc b/y2023/control_loops/superstructure/superstructure.cc
index 0ee1061..bfb7a9d 100644
--- a/y2023/control_loops/superstructure/superstructure.cc
+++ b/y2023/control_loops/superstructure/superstructure.cc
@@ -134,10 +134,14 @@
   if (reading > kInvalidReading || !std::isfinite(reading)) {
     return std::nullopt;
   }
-  const TimeOfFlight *calibration = CHECK_NOTNULL(
-      CHECK_NOTNULL(constants_fetcher_.constants().robot())->tof());
+  auto robot = constants_fetcher_.constants().robot();
+  CHECK(robot != nullptr);
+  const TimeOfFlight *calibration =
+      constants_fetcher_.constants().robot()->tof();
+  CHECK(calibration != nullptr);
   // TODO(james): Use a generic interpolation table class.
-  auto table = CHECK_NOTNULL(calibration->interpolation_table());
+  auto table = calibration->interpolation_table();
+  CHECK(table != nullptr);
   CHECK_EQ(2u, table->size());
   double x1 = table->Get(0)->tof_reading();
   double x2 = table->Get(1)->tof_reading();
diff --git a/y2023/joystick_reader.cc b/y2023/joystick_reader.cc
index 45418bc..6e62c5b 100644
--- a/y2023/joystick_reader.cc
+++ b/y2023/joystick_reader.cc
@@ -533,7 +533,8 @@
       auto builder = target_selector_hint_sender_.MakeBuilder();
       auto hint_builder = builder.MakeBuilder<TargetSelectorHint>();
       hint_builder.add_substation_pickup(true);
-      hint_builder.add_robot_side(CHECK_NOTNULL(current_setpoint_)->side);
+      CHECK(current_setpoint_ != nullptr);
+      hint_builder.add_robot_side(current_setpoint_->side);
       if (builder.Send(hint_builder.Finish()) != aos::RawSender::Error::kOk) {
         AOS_LOG(ERROR, "Sending target selector hint failed.\n");
       }
@@ -542,7 +543,8 @@
       auto hint_builder = builder.MakeBuilder<TargetSelectorHint>();
       hint_builder.add_row(placing_row.value());
       hint_builder.add_spot(placing_spot.value());
-      hint_builder.add_robot_side(CHECK_NOTNULL(current_setpoint_)->side);
+      CHECK(current_setpoint_ != nullptr);
+      hint_builder.add_robot_side(current_setpoint_->side);
       if (builder.Send(hint_builder.Finish()) != aos::RawSender::Error::kOk) {
         AOS_LOG(ERROR, "Sending target selector hint failed.\n");
       }
diff --git a/y2023/localizer/localizer.cc b/y2023/localizer/localizer.cc
index 6f9a16b..a00ebe6 100644
--- a/y2023/localizer/localizer.cc
+++ b/y2023/localizer/localizer.cc
@@ -264,12 +264,12 @@
 
   switch (utils_.Alliance()) {
     case aos::Alliance::kRed:
-      ignore_tags =
-          CHECK_NOTNULL(constants_fetcher_.constants().ignore_targets()->red());
+      ignore_tags = constants_fetcher_.constants().ignore_targets()->red();
+      CHECK(ignore_tags != nullptr);
       break;
     case aos::Alliance::kBlue:
-      ignore_tags = CHECK_NOTNULL(
-          constants_fetcher_.constants().ignore_targets()->blue());
+      ignore_tags = constants_fetcher_.constants().ignore_targets()->blue();
+      CHECK(ignore_tags != nullptr);
       break;
     case aos::Alliance::kInvalid:
       return true;
diff --git a/y2023/wpilib_interface.cc b/y2023/wpilib_interface.cc
index 492d44b..d0d952c 100644
--- a/y2023/wpilib_interface.cc
+++ b/y2023/wpilib_interface.cc
@@ -133,7 +133,7 @@
     // device temp is not timesynced so don't add it to the list of signals
     device_temp_.SetUpdateFrequency(kCANUpdateFreqHz);
 
-    CHECK_NOTNULL(signals);
+    CHECK(signals != nullptr);
 
     supply_voltage_.SetUpdateFrequency(kCANUpdateFreqHz);
     signals->push_back(&supply_voltage_);