Use std::string_view and fmtlib across all libraries (#3402)

- Twine, StringRef, Format, and NativeFormatting have been removed
- Logging now uses fmtlib style formatting
- Nearly all uses of wpi::outs/errs have been replaced with fmt::print() or
std::puts()/std::fputs() (for unformatted strings).
- A wpi/fmt/raw_ostream.h header has been added to enable
fmt::print() with wpi::raw_ostream

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

@@ -4,6 +4,8 @@
 
 #include "hal/AddressableLED.h"
 
+#include <fmt/format.h>
+
 #include "DigitalInternal.h"
 #include "HALInitializer.h"
 #include "HALInternal.h"
@@ -113,9 +115,11 @@ void HAL_SetAddressableLEDLength(HAL_AddressableLEDHandle handle,
   }
   if (length > HAL_kAddressableLEDMaxLength || length < 0) {
     *status = PARAMETER_OUT_OF_RANGE;
-    hal::SetLastError(status, "LED length must be less than or equal to " +
-                                  wpi::Twine(HAL_kAddressableLEDMaxLength) +
-                                  ". " + wpi::Twine(length) + " was requested");
+    hal::SetLastError(
+        status,
+        fmt::format(
+            "LED length must be less than or equal to {}. {} was requested",
+            HAL_kAddressableLEDMaxLength, length));
     return;
   }
   SimAddressableLEDData[led->index].length = length;
@@ -131,10 +135,11 @@ void HAL_WriteAddressableLEDData(HAL_AddressableLEDHandle handle,
   }
   if (length > SimAddressableLEDData[led->index].length) {
     *status = PARAMETER_OUT_OF_RANGE;
-    hal::SetLastError(status,
-                      "Data length must be less than or equal to " +
-                          wpi::Twine(SimAddressableLEDData[led->index].length) +
-                          ". " + wpi::Twine(length) + " was requested");
+    hal::SetLastError(
+        status,
+        fmt::format(
+            "Data length must be less than or equal to {}. {} was requested",
+            SimAddressableLEDData[led->index].length, length));
     return;
   }
   SimAddressableLEDData[led->index].SetData(data, length);

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

@@ -13,9 +13,9 @@
 #include <cstring>
 #include <string>
 
+#include <fmt/format.h>
 #include <wpi/condition_variable.h>
 #include <wpi/mutex.h>
-#include <wpi/raw_ostream.h>
 
 #include "HALInitializer.h"
 #include "hal/cpp/fpga_clock.h"
@@ -83,14 +83,16 @@ int32_t HAL_SendError(HAL_Bool isError, int32_t errorCode, HAL_Bool isLVCode,
   if (i == KEEP_MSGS || (curTime - prevMsgTime[i]) >= std::chrono::seconds(1)) {
     printMsg = true;
     if (printMsg) {
+      fmt::memory_buffer buf;
       if (location && location[0] != '\0') {
-        std::fprintf(stderr, "%s at %s: ", isError ? "Error" : "Warning",
-                     location);
+        fmt::format_to(buf, "{} at {}: ", isError ? "Error" : "Warning",
+                       location);
       }
-      std::fprintf(stderr, "%s\n", details);
+      fmt::format_to(buf, "{}\n", details);
       if (callStack && callStack[0] != '\0') {
-        std::fprintf(stderr, "%s\n", callStack);
+        fmt::format_to(buf, "{}\n", callStack);
       }
+      std::fwrite(buf.data(), buf.size(), 1, stderr);
     }
     if (i == KEEP_MSGS) {
       // replace the oldest one
@@ -114,8 +116,8 @@ int32_t HAL_SendConsoleLine(const char* line) {
   if (handler) {
     return handler(line);
   }
-  wpi::outs() << line << "\n";
-  wpi::outs().flush();
+  std::puts(line);
+  std::fflush(stdout);
   return 0;
 }
 

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

@@ -4,12 +4,14 @@
 
 #include "hal/Extensions.h"
 
+#include <cstdio>
+#include <string_view>
 #include <vector>
 
-#include <wpi/SmallString.h>
-#include <wpi/StringRef.h>
+#include <fmt/format.h>
+#include <wpi/SmallVector.h>
+#include <wpi/StringExtras.h>
 #include <wpi/fs.h>
-#include <wpi/raw_ostream.h>
 #include <wpi/spinlock.h>
 
 #if defined(WIN32) || defined(_WIN32)
@@ -24,7 +26,7 @@
 #define DLOPEN(a) LoadLibraryA(a)
 #define DLSYM GetProcAddress
 #define DLCLOSE FreeLibrary
-#define DLERROR "error #" << GetLastError()
+#define DLERROR fmt::format("error #{}", GetLastError())
 #else
 #define DELIM ':'
 #define HTYPE void*
@@ -53,30 +55,26 @@ extern "C" {
 
 int HAL_LoadOneExtension(const char* library) {
   int rc = 1;  // It is expected and reasonable not to find an extra simulation
-  wpi::outs() << "HAL Extensions: Attempting to load: "
-              << fs::path{library}.stem().string() << "\n";
-  wpi::outs().flush();
+  fmt::print("HAL Extensions: Attempting to load: {}\n",
+             fs::path{library}.stem().string());
+  std::fflush(stdout);
   HTYPE handle = DLOPEN(library);
 #if !defined(WIN32) && !defined(_WIN32)
   if (!handle) {
-    wpi::SmallString<128> libraryName("lib");
-    libraryName += library;
 #if defined(__APPLE__)
-    libraryName += ".dylib";
+    auto libraryName = fmt::format("lib{}.dylib", library);
 #else
-    libraryName += ".so";
+    auto libraryName = fmt::format("lib{}.so", library);
 #endif
-    wpi::outs() << "HAL Extensions: Load failed: " << DLERROR
-                << "\nTrying modified name: "
-                << fs::path{libraryName.str()}.stem() << "\n";
-    wpi::outs().flush();
+    fmt::print("HAL Extensions: Load failed: {}\nTrying modified name: {}\n",
+               DLERROR, fs::path{libraryName}.stem().string());
+    std::fflush(stdout);
     handle = DLOPEN(libraryName.c_str());
   }
 #endif
   if (!handle) {
-    wpi::outs() << "HAL Extensions: Failed to load library: " << DLERROR
-                << '\n';
-    wpi::outs().flush();
+    fmt::print("HAL Extensions: Failed to load library: {}\n", DLERROR);
+    std::fflush(stdout);
     return rc;
   }
 
@@ -88,32 +86,30 @@ int HAL_LoadOneExtension(const char* library) {
   }
 
   if (rc != 0) {
-    wpi::outs() << "HAL Extensions: Failed to load extension\n";
-    wpi::outs().flush();
+    std::puts("HAL Extensions: Failed to load extension");
+    std::fflush(stdout);
     DLCLOSE(handle);
   } else {
-    wpi::outs() << "HAL Extensions: Successfully loaded extension\n";
-    wpi::outs().flush();
+    std::puts("HAL Extensions: Successfully loaded extension");
+    std::fflush(stdout);
   }
   return rc;
 }
 
 int HAL_LoadExtensions(void) {
   int rc = 1;
-  wpi::SmallVector<wpi::StringRef, 2> libraries;
+  wpi::SmallVector<std::string_view, 2> libraries;
   const char* e = std::getenv("HALSIM_EXTENSIONS");
   if (!e) {
     if (GetShowNotFoundMessage()) {
-      wpi::outs() << "HAL Extensions: No extensions found\n";
-      wpi::outs().flush();
+      std::puts("HAL Extensions: No extensions found");
+      std::fflush(stdout);
     }
     return rc;
   }
-  wpi::StringRef env{e};
-  env.split(libraries, DELIM, -1, false);
-  for (auto& libref : libraries) {
-    wpi::SmallString<128> library(libref);
-    rc = HAL_LoadOneExtension(library.c_str());
+  wpi::split(e, libraries, DELIM, -1, false);
+  for (auto& library : libraries) {
+    rc = HAL_LoadOneExtension(std::string(library).c_str());
     if (rc < 0) {
       break;
     }

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

@@ -4,10 +4,10 @@
 
 #include "hal/HAL.h"
 
+#include <cstdio>
 #include <vector>
 
 #include <wpi/mutex.h>
-#include <wpi/raw_ostream.h>
 #include <wpi/spinlock.h>
 
 #ifdef _WIN32
@@ -351,7 +351,11 @@ HAL_Bool HAL_Initialize(int32_t timeout, int32_t mode) {
   }
 #endif  // _WIN32
 
-  wpi::outs().SetUnbuffered();
+#ifndef _WIN32
+  setlinebuf(stdin);
+  setlinebuf(stdout);
+#endif
+
   if (HAL_LoadExtensions() < 0) {
     return false;
   }

hal/src/main/native/sim/HALInternal.h

@@ -6,14 +6,14 @@
 
 #include <stdint.h>
 
-#include <wpi/Twine.h>
+#include <string_view>
 
 namespace hal {
-void SetLastError(int32_t* status, const wpi::Twine& value);
-void SetLastErrorIndexOutOfRange(int32_t* status, const wpi::Twine& message,
+void SetLastError(int32_t* status, std::string_view value);
+void SetLastErrorIndexOutOfRange(int32_t* status, std::string_view message,
                                  int32_t minimum, int32_t maximum,
                                  int32_t channel);
-void SetLastErrorPreviouslyAllocated(int32_t* status, const wpi::Twine& message,
+void SetLastErrorPreviouslyAllocated(int32_t* status, std::string_view message,
                                      int32_t channel,
-                                     const wpi::Twine& previousAllocation);
+                                     std::string_view previousAllocation);
 }  // namespace hal

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

@@ -8,6 +8,7 @@
 #include <cstdio>
 #include <thread>
 
+#include <fmt/format.h>
 #include <wpi/timestamp.h>
 
 #include "MockHooksInternal.h"
@@ -83,7 +84,7 @@ void HALSIM_WaitForProgramStart(void) {
   int count = 0;
   while (!programStarted) {
     count++;
-    std::printf("Waiting for program start signal: %d\n", count);
+    fmt::print("Waiting for program start signal: {}\n", count);
     std::this_thread::sleep_for(std::chrono::milliseconds(500));
   }
 }

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

@@ -4,6 +4,8 @@
 
 #include "hal/PDP.h"
 
+#include <fmt/format.h>
+
 #include "CANAPIInternal.h"
 #include "HALInitializer.h"
 #include "HALInternal.h"
@@ -28,7 +30,7 @@ extern "C" {
 HAL_PDPHandle HAL_InitializePDP(int32_t module, int32_t* status) {
   if (!HAL_CheckPDPModule(module)) {
     *status = PARAMETER_OUT_OF_RANGE;
-    hal::SetLastError(status, "Invalid pdp module " + wpi::Twine(module));
+    hal::SetLastError(status, fmt::format("Invalid pdp module {}", module));
     return HAL_kInvalidHandle;
   }
   hal::init::CheckInit();

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

@@ -4,8 +4,7 @@
 
 #include "hal/SimDevice.h"
 
-#include <wpi/SmallString.h>
-#include <wpi/raw_ostream.h>
+#include <fmt/format.h>
 
 #include "HALInitializer.h"
 #include "mockdata/SimDeviceDataInternal.h"
@@ -66,19 +65,12 @@ void HAL_ResetSimValue(HAL_SimValueHandle handle) {
 }
 
 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());
+  m_handle = HAL_CreateSimDevice(fmt::format("{}[{}]", name, index).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());
+  m_handle = HAL_CreateSimDevice(
+      fmt::format("{}[{},{}]", name, index, channel).c_str());
 }
 
 }  // extern "C"

hal/src/main/native/sim/mockdata/SimDeviceData.cpp

@@ -6,6 +6,8 @@
 
 #include <algorithm>
 
+#include <wpi/StringExtras.h>
+
 #include "SimDeviceDataInternal.h"
 
 using namespace hal;
@@ -71,7 +73,7 @@ void SimDeviceData::SetDeviceEnabled(const char* prefix, bool enabled) {
 bool SimDeviceData::IsDeviceEnabled(const char* name) {
   std::scoped_lock lock(m_mutex);
   for (const auto& elem : m_prefixEnabled) {
-    if (wpi::StringRef{name}.startswith(elem.first)) {
+    if (wpi::starts_with(name, elem.first)) {
       return elem.second;
     }
   }
@@ -83,7 +85,7 @@ HAL_SimDeviceHandle SimDeviceData::CreateDevice(const char* name) {
 
   // don't create if disabled
   for (const auto& elem : m_prefixEnabled) {
-    if (wpi::StringRef{name}.startswith(elem.first)) {
+    if (wpi::starts_with(name, elem.first)) {
       if (elem.second) {
         break;  // enabled
       }
@@ -272,7 +274,7 @@ int32_t SimDeviceData::RegisterDeviceCreatedCallback(
   // initial notifications
   if (initialNotify) {
     for (auto&& device : m_devices) {
-      if (wpi::StringRef{device->name}.startswith(prefix)) {
+      if (wpi::starts_with(device->name, prefix)) {
         callback(device->name.c_str(), param, device->handle);
       }
     }
@@ -332,7 +334,7 @@ void SimDeviceData::EnumerateDevices(const char* prefix, void* param,
                                      HALSIM_SimDeviceCallback callback) {
   std::scoped_lock lock(m_mutex);
   for (auto&& device : m_devices) {
-    if (wpi::StringRef{device->name}.startswith(prefix)) {
+    if (wpi::starts_with(device->name, prefix)) {
       callback(device->name.c_str(), param, device->handle);
     }
   }

hal/src/main/native/sim/mockdata/SimDeviceDataInternal.h

@@ -11,6 +11,7 @@
 #include <utility>
 #include <vector>
 
+#include <wpi/StringExtras.h>
 #include <wpi/StringMap.h>
 #include <wpi/UidVector.h>
 #include <wpi/spinlock.h>
@@ -118,7 +119,7 @@ class SimPrefixCallbackRegistry {
   void Invoke(const char* name, U&&... u) const {
     if (m_callbacks) {
       for (auto&& cb : *m_callbacks) {
-        if (wpi::StringRef{name}.startswith(cb.prefix)) {
+        if (wpi::starts_with(name, cb.prefix)) {
           cb.callback(name, cb.param, std::forward<U>(u)...);
         }
       }