Add simulation generic device/value support

This allows high-level library classes to implement enhanced simulation
support even if no low-level corresponding simulation library exists, and
avoids the need for bit-banging complex interfaces like SPI or CAN.

hal/src/main/native/sim/SimDevice.cpp

@@ -0,0 +1,75 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2019 FIRST. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "hal/SimDevice.h"
+
+#include <wpi/SmallString.h>
+#include <wpi/raw_ostream.h>
+
+#include "HALInitializer.h"
+#include "mockdata/SimDeviceDataInternal.h"
+
+using namespace hal;
+
+namespace hal {
+namespace init {
+void InitializeSimDevice() {}
+}  // namespace init
+}  // namespace hal
+
+extern "C" {
+
+HAL_SimDeviceHandle HAL_CreateSimDevice(const char* name) {
+  hal::init::CheckInit();
+  return SimSimDeviceData->CreateDevice(name);
+}
+
+void HAL_FreeSimDevice(HAL_SimDeviceHandle handle) {
+  SimSimDeviceData->FreeDevice(handle);
+}
+
+HAL_SimValueHandle HAL_CreateSimValue(HAL_SimDeviceHandle device,
+                                      const char* name, HAL_Bool readonly,
+                                      const struct HAL_Value* initialValue) {
+  return SimSimDeviceData->CreateValue(device, name, readonly, 0, nullptr,
+                                       *initialValue);
+}
+
+HAL_SimValueHandle HAL_CreateSimValueEnum(HAL_SimDeviceHandle device,
+                                          const char* name, HAL_Bool readonly,
+                                          int32_t numOptions,
+                                          const char** options,
+                                          int32_t initialValue) {
+  return SimSimDeviceData->CreateValue(device, name, readonly, numOptions,
+                                       options, HAL_MakeEnum(initialValue));
+}
+
+void HAL_GetSimValue(HAL_SimValueHandle handle, struct HAL_Value* value) {
+  *value = SimSimDeviceData->GetValue(handle);
+}
+
+void HAL_SetSimValue(HAL_SimValueHandle handle, const struct HAL_Value* value) {
+  SimSimDeviceData->SetValue(handle, *value);
+}
+
+hal::SimDevice::SimDevice(const char* name, int index) {
+  wpi::SmallString<128> fullname;
+  wpi::raw_svector_ostream os(fullname);
+  os << name << '[' << index << ']';
+
+  m_handle = HAL_CreateSimDevice(fullname.c_str());
+}
+
+hal::SimDevice::SimDevice(const char* name, int index, int channel) {
+  wpi::SmallString<128> fullname;
+  wpi::raw_svector_ostream os(fullname);
+  os << name << '[' << index << ',' << channel << ']';
+
+  m_handle = HAL_CreateSimDevice(fullname.c_str());
+}
+
+}  // extern "C"