[wpilibc] Fix missing symbols on Windows (wpilibsuite#7140)

Windows doesn't support direct static variable access across library boundaries in a mixed static/shared environment, so change to accessor functions.

Author: spacey-sooty

wpilibc/src/main/native/cpp/DigitalOutput.cpp

@@ -135,8 +135,8 @@ void DigitalOutput::DisablePWM() {
   int32_t status = 0;
 
   // Disable the output by routing to a dead bit.
-  HAL_SetDigitalPWMOutputChannel(m_pwmGenerator, SensorUtil::kDigitalChannels,
-                                 &status);
+  HAL_SetDigitalPWMOutputChannel(m_pwmGenerator,
+                                 SensorUtil::GetNumDigitalChannels(), &status);
   FRC_CheckErrorStatus(status, "Channel {}", m_channel);
 
   HAL_FreeDigitalPWM(m_pwmGenerator);

wpilibc/src/main/native/cpp/LEDPattern.cpp

@@ -104,7 +104,7 @@ LEDPattern LEDPattern::Blink(units::second_t onTime, units::second_t offTime) {
     if (wpi::Now() % totalMicros < onMicros) {
       self.ApplyTo(data, writer);
     } else {
-      LEDPattern::kOff.ApplyTo(data, writer);
+      LEDPattern::Off().ApplyTo(data, writer);
     }
   }};
 }
@@ -118,7 +118,7 @@ LEDPattern LEDPattern::SynchronizedBlink(std::function<bool()> signal) {
     if (signal()) {
       self.ApplyTo(data, writer);
     } else {
-      LEDPattern::kOff.ApplyTo(data, writer);
+      LEDPattern::Off().ApplyTo(data, writer);
     }
   }};
 }
@@ -198,7 +198,9 @@ LEDPattern LEDPattern::AtBrightness(double relativeBrightness) {
 
 // Static constants and functions
 
-LEDPattern LEDPattern::kOff = LEDPattern::Solid(Color::kBlack);
+LEDPattern LEDPattern::Off() {
+  return LEDPattern::Solid(Color::kBlack);
+}
 
 LEDPattern LEDPattern::Solid(const Color color) {
   return LEDPattern{[=](auto data, auto writer) {
@@ -228,7 +230,7 @@ LEDPattern LEDPattern::ProgressMaskLayer(
 LEDPattern LEDPattern::Steps(std::span<const std::pair<double, Color>> steps) {
   if (steps.size() == 0) {
     // no colors specified
-    return LEDPattern::kOff;
+    return LEDPattern::Off();
   }
   if (steps.size() == 1 && steps[0].first == 0) {
     // only one color specified, just show a static color
@@ -264,7 +266,7 @@ LEDPattern LEDPattern::Steps(
 LEDPattern LEDPattern::Gradient(std::span<const Color> colors) {
   if (colors.size() == 0) {
     // no colors specified
-    return LEDPattern::kOff;
+    return LEDPattern::Off();
   }
   if (colors.size() == 1) {
     // only one color specified, just show a static color

wpilibc/src/main/native/cpp/SensorUtil.cpp

@@ -13,12 +13,6 @@
 
 using namespace frc;
 
-const int SensorUtil::kDigitalChannels = HAL_GetNumDigitalChannels();
-const int SensorUtil::kAnalogInputs = HAL_GetNumAnalogInputs();
-const int SensorUtil::kAnalogOutputs = HAL_GetNumAnalogOutputs();
-const int SensorUtil::kPwmChannels = HAL_GetNumPWMChannels();
-const int SensorUtil::kRelayChannels = HAL_GetNumRelayHeaders();
-
 int SensorUtil::GetDefaultCTREPCMModule() {
   return 0;
 }
@@ -46,3 +40,23 @@ bool SensorUtil::CheckAnalogInputChannel(int channel) {
 bool SensorUtil::CheckAnalogOutputChannel(int channel) {
   return HAL_CheckAnalogOutputChannel(channel);
 }
+
+int SensorUtil::GetNumDigitalChannels() {
+  return HAL_GetNumDigitalChannels();
+}
+
+int SensorUtil::GetNumAnalogInputs() {
+  return HAL_GetNumAnalogInputs();
+}
+
+int SensorUtil::GetNumAnalogOuputs() {
+  return HAL_GetNumAnalogOutputs();
+}
+
+int SensorUtil::GetNumPwmChannels() {
+  return HAL_GetNumPWMChannels();
+}
+
+int SensorUtil::GetNumRelayChannels() {
+  return HAL_GetNumRelayHeaders();
+}

wpilibc/src/main/native/include/frc/LEDPattern.h

@@ -246,7 +246,7 @@ class LEDPattern {
   LEDPattern AtBrightness(double relativeBrightness);
 
   /** A pattern that turns off all LEDs. */
-  static LEDPattern kOff;
+  static LEDPattern Off();
 
   /**
    * Creates a pattern that displays a single static color along the entire

wpilibc/src/main/native/include/frc/SensorUtil.h

@@ -78,11 +78,11 @@ class SensorUtil final {
    */
   static bool CheckAnalogOutputChannel(int channel);
 
-  static const int kDigitalChannels;
-  static const int kAnalogInputs;
-  static const int kAnalogOutputs;
-  static const int kPwmChannels;
-  static const int kRelayChannels;
+  static int GetNumDigitalChannels();
+  static int GetNumAnalogInputs();
+  static int GetNumAnalogOuputs();
+  static int GetNumPwmChannels();
+  static int GetNumRelayChannels();
 };
 
 }  // namespace frc