From eafa947338614730d76f0a67409a990d9613acc0 Mon Sep 17 00:00:00 2001
From: Tyler Veness <calcmogul@gmail.com>
Date: Sat, 25 Dec 2021 05:19:43 -0800
Subject: [PATCH] [wpimath] Make copies of trajectory constraint arguments
 (#3832)

This avoids stack-use-after-scope bugs in code like the following when
the original argument goes out of scope:
```cpp
frc2::Command* RobotContainer::GetAutonomousCommand() {
  // Create a voltage constraint to ensure we don't accelerate too fast
  frc::DifferentialDriveVoltageConstraint autoVoltageConstraint(
      frc::SimpleMotorFeedforward<units::meters>(
          DriveConstants::ks, DriveConstants::kv, DriveConstants::ka),
      DriveConstants::kDriveKinematics, 10_V);
```
---
 .../constraint/DifferentialDriveKinematicsConstraint.h        | 2 +-
 .../constraint/DifferentialDriveVoltageConstraint.h           | 4 ++--
 .../trajectory/constraint/MecanumDriveKinematicsConstraint.h  | 2 +-
 .../trajectory/constraint/SwerveDriveKinematicsConstraint.h   | 2 +-
 4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/wpimath/src/main/native/include/frc/trajectory/constraint/DifferentialDriveKinematicsConstraint.h b/wpimath/src/main/native/include/frc/trajectory/constraint/DifferentialDriveKinematicsConstraint.h
index ad643bfa42..0edd8cc432 100644
--- a/wpimath/src/main/native/include/frc/trajectory/constraint/DifferentialDriveKinematicsConstraint.h
+++ b/wpimath/src/main/native/include/frc/trajectory/constraint/DifferentialDriveKinematicsConstraint.h
@@ -32,7 +32,7 @@ class WPILIB_DLLEXPORT DifferentialDriveKinematicsConstraint
                             units::meters_per_second_t speed) const override;
 
  private:
-  const DifferentialDriveKinematics& m_kinematics;
+  DifferentialDriveKinematics m_kinematics;
   units::meters_per_second_t m_maxSpeed;
 };
 }  // namespace frc
diff --git a/wpimath/src/main/native/include/frc/trajectory/constraint/DifferentialDriveVoltageConstraint.h b/wpimath/src/main/native/include/frc/trajectory/constraint/DifferentialDriveVoltageConstraint.h
index 06d0e50078..40a0d8eff4 100644
--- a/wpimath/src/main/native/include/frc/trajectory/constraint/DifferentialDriveVoltageConstraint.h
+++ b/wpimath/src/main/native/include/frc/trajectory/constraint/DifferentialDriveVoltageConstraint.h
@@ -44,8 +44,8 @@ class WPILIB_DLLEXPORT DifferentialDriveVoltageConstraint
                             units::meters_per_second_t speed) const override;
 
  private:
-  const SimpleMotorFeedforward<units::meter>& m_feedforward;
-  const DifferentialDriveKinematics& m_kinematics;
+  SimpleMotorFeedforward<units::meter> m_feedforward;
+  DifferentialDriveKinematics m_kinematics;
   units::volt_t m_maxVoltage;
 };
 }  // namespace frc
diff --git a/wpimath/src/main/native/include/frc/trajectory/constraint/MecanumDriveKinematicsConstraint.h b/wpimath/src/main/native/include/frc/trajectory/constraint/MecanumDriveKinematicsConstraint.h
index 816d8ef405..ac47dbfeb5 100644
--- a/wpimath/src/main/native/include/frc/trajectory/constraint/MecanumDriveKinematicsConstraint.h
+++ b/wpimath/src/main/native/include/frc/trajectory/constraint/MecanumDriveKinematicsConstraint.h
@@ -33,7 +33,7 @@ class WPILIB_DLLEXPORT MecanumDriveKinematicsConstraint
                             units::meters_per_second_t speed) const override;
 
  private:
-  const MecanumDriveKinematics& m_kinematics;
+  MecanumDriveKinematics m_kinematics;
   units::meters_per_second_t m_maxSpeed;
 };
 }  // namespace frc
diff --git a/wpimath/src/main/native/include/frc/trajectory/constraint/SwerveDriveKinematicsConstraint.h b/wpimath/src/main/native/include/frc/trajectory/constraint/SwerveDriveKinematicsConstraint.h
index 67e9fc9272..d26497735d 100644
--- a/wpimath/src/main/native/include/frc/trajectory/constraint/SwerveDriveKinematicsConstraint.h
+++ b/wpimath/src/main/native/include/frc/trajectory/constraint/SwerveDriveKinematicsConstraint.h
@@ -32,7 +32,7 @@ class SwerveDriveKinematicsConstraint : public TrajectoryConstraint {
                             units::meters_per_second_t speed) const override;
 
  private:
-  const frc::SwerveDriveKinematics<NumModules>& m_kinematics;
+  frc::SwerveDriveKinematics<NumModules> m_kinematics;
   units::meters_per_second_t m_maxSpeed;
 };
 }  // namespace frc