tests: Add an implementation of the Logger interface for use gtests.

On exiting log types (panic and fatal), the message is set to an
ADD_FAILURE_AT macro, and the test is exited by throwing an otherwise
unexpected exception. On non-exiting log types, the message is sent to
the SUCCEEDED macro which currently doesn't output anything.

Change-Id: I1bb569e6cb8308dbc4c3e04eea7a962bd2b1ddd8
Reviewed-on: https://gem5-review.googlesource.com/6264
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
diff --git a/src/base/SConscript b/src/base/SConscript
index fb14c4d..efb7743 100644
--- a/src/base/SConscript
+++ b/src/base/SConscript
@@ -40,7 +40,7 @@
 Source('imgwriter.cc')
 Source('bmpwriter.cc')
 Source('callback.cc')
-Source('cprintf.cc')
+Source('cprintf.cc', add_tags='gtest lib')
 Source('debug.cc')
 if env['USE_FENV']:
     Source('fenv.c')
diff --git a/src/base/gtest/SConscript b/src/base/gtest/SConscript
new file mode 100644
index 0000000..4bc34b5
--- /dev/null
+++ b/src/base/gtest/SConscript
@@ -0,0 +1,28 @@
+# Copyright 2017 Google Inc.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met: redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer;
+# redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution;
+# neither the name of the copyright holders nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+Import('*')
+
+Source('logging.cc', tags=('gtest lib', 'gtest logging'))
diff --git a/src/base/gtest/logging.cc b/src/base/gtest/logging.cc
new file mode 100644
index 0000000..92d2602
--- /dev/null
+++ b/src/base/gtest/logging.cc
@@ -0,0 +1,82 @@
+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <gtest/gtest.h>
+
+#include <array>
+#include <string>
+
+#include "base/cprintf.hh"
+#include "base/logging.hh"
+
+namespace {
+
+// This custom exception type will help prevent fatal exceptions from being
+// caught by other code in gem5 and let them escape to the gtest framework.
+// Unfortunately that results in a somewhat confusing message about an unknown
+// exception being thrown after the panic/fatal message has been printed, but
+// there will at least be some indication what went wrong.
+struct GTestException
+{};
+
+class GTestLogger : public Logger
+{
+  public:
+    using Logger::Logger;
+
+  protected:
+    void log(const Loc &loc, std::string s) override { SUCCEED() << s; }
+};
+
+class GTestExitLogger : public Logger
+{
+  public:
+    using Logger::Logger;
+
+  protected:
+    void
+    log(const Loc &loc, std::string s) override
+    {
+        ADD_FAILURE_AT(loc.file, loc.line) << s;
+    }
+    // Throw an exception to escape down to the gtest framework.
+    void exit() override { throw GTestException(); }
+};
+
+GTestExitLogger panicLogger("panic: ");
+GTestExitLogger fatalLogger("fatal: ");
+GTestLogger warnLogger("warn: ");
+GTestLogger infoLogger("info: ");
+GTestLogger hackLogger("hack: ");
+
+} // anonymous namespace
+
+Logger &Logger::getPanic() { return panicLogger; }
+Logger &Logger::getFatal() { return fatalLogger; }
+Logger &Logger::getWarn() { return warnLogger; }
+Logger &Logger::getInfo() { return infoLogger; }
+Logger &Logger::getHack() { return hackLogger; }