Prepare cscore for merge into allwpilib.

cscore/src/main/native/cpp/Log.cpp

@@ -0,0 +1,45 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2016-2018 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 "Log.h"
+
+#include <llvm/Path.h>
+#include <llvm/SmallString.h>
+#include <llvm/StringRef.h>
+#include <llvm/raw_ostream.h>
+
+using namespace cs;
+
+static void def_log_func(unsigned int level, const char* file,
+                         unsigned int line, const char* msg) {
+  llvm::SmallString<128> buf;
+  llvm::raw_svector_ostream oss(buf);
+  if (level == 20) {
+    oss << "CS: " << msg << '\n';
+    llvm::errs() << oss.str();
+    return;
+  }
+
+  llvm::StringRef levelmsg;
+  if (level >= 50)
+    levelmsg = "CRITICAL: ";
+  else if (level >= 40)
+    levelmsg = "ERROR: ";
+  else if (level >= 30)
+    levelmsg = "WARNING: ";
+  else
+    return;
+  oss << "CS: " << levelmsg << msg << " (" << llvm::sys::path::filename(file)
+      << ':' << line << ")\n";
+  llvm::errs() << oss.str();
+}
+
+Logger::Logger() { SetDefaultLogger(); }
+
+Logger::~Logger() {}
+
+void Logger::SetDefaultLogger() { SetLogger(def_log_func); }