Mojo: Add logging macros (and supporting code) for use in mojo/public/cpp.

mojo/public/cpp/environment/tests/logging_unittest.cc

Index: mojo/public/cpp/environment/tests/logging_unittest.cc
diff --git a/mojo/public/cpp/environment/tests/logging_unittest.cc b/mojo/public/cpp/environment/tests/logging_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2afad88aff26f0ca944220f21727e6eff642d868
--- /dev/null
+++ b/mojo/public/cpp/environment/tests/logging_unittest.cc
@@ -0,0 +1,448 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <stdlib.h>
+
+#include <sstream>
+#include <string>
+
+#include "mojo/public/cpp/environment/environment.h"
+#include "mojo/public/cpp/environment/logging.h"
+#include "mojo/public/cpp/system/macros.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+// A macro, so it can be automatically joined with other string literals. (Not
+// simply __FILE__, since that may contain a path.)
+#define OUR_FILENAME "logging_unittest.cc"
+
+namespace mojo {
+namespace {
+
+class LoggingTest : public testing::Test {
+ public:
+  LoggingTest() : environment_(NULL, &kMockLogger) {
+    minimum_log_level_ = MOJO_LOG_LEVEL_INFO;
+    ResetMockLogger();
+  }
+  virtual ~LoggingTest() {}
+
+ protected:
+  // Note: Does not reset |minimum_log_level_|.
+  static void ResetMockLogger() {
+    log_message_was_called_ = false;
+    last_log_level_ = MOJO_LOG_LEVEL_INFO;
+    last_message_.clear();
+  }
+
+  static bool log_message_was_called() { return log_message_was_called_; }
+  static MojoLogLevel last_log_level() { return last_log_level_; }
+  static const std::string& last_message() { return last_message_; }
+
+ private:
+  // Note: We record calls even if |log_level| is below |minimum_log_level_|
+  // (since the macros should mostly avoid this, and we want to be able to check
+  // that they do).
+  static void MockLogMessage(MojoLogLevel log_level, const char* message) {
+    log_message_was_called_ = true;
+    last_log_level_ = log_level;
+    last_message_ = message;
+  }
+
+  static MojoLogLevel MockGetMinimumLogLevel() {
+    return minimum_log_level_;
+  }
+
+  static void MockSetMinimumLogLevel(MojoLogLevel minimum_log_level) {
+    minimum_log_level_ = minimum_log_level;
+  }
+
+  Environment environment_;
+
+  static const MojoLogger kMockLogger;
+  static MojoLogLevel minimum_log_level_;
+  static bool log_message_was_called_;
+  static MojoLogLevel last_log_level_;
+  static std::string last_message_;
+
+  MOJO_DISALLOW_COPY_AND_ASSIGN(LoggingTest);
+};
+
+// static
+const MojoLogger LoggingTest::kMockLogger = {
+  &LoggingTest::MockLogMessage,
+  &LoggingTest::MockGetMinimumLogLevel,
+  &LoggingTest::MockSetMinimumLogLevel
+};
+
+// static
+MojoLogLevel LoggingTest::minimum_log_level_ = MOJO_LOG_LEVEL_INFO;
+
+// static
+bool LoggingTest::log_message_was_called_ = MOJO_LOG_LEVEL_INFO;
+
+// static
+MojoLogLevel LoggingTest::last_log_level_ = MOJO_LOG_LEVEL_INFO;
+
+// static
+std::string LoggingTest::last_message_;
+
+std::string ExpectedLogMessage(int line, const char* message) {
+  std::ostringstream s;
+  s << OUR_FILENAME "(" << line << "): " << message;
+  return s.str();
+}
+
+// A function returning |bool| that shouldn't be called.
+bool NotCalled() {
+  abort();
+  // I think all compilers are smart enough to recognize that nothing is run
+  // after |abort()|. (Some definitely complain that things after it are
+  // unreachable.)
+}
+
+TEST_F(LoggingTest, InternalLogMessage) {
+  internal::LogMessage("foo.cc", 123, MOJO_LOG_LEVEL_INFO).stream()
+      << "hello " << "world";
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_INFO, last_log_level());
+  EXPECT_EQ("foo.cc(123): hello world", last_message());
+
+  ResetMockLogger();
+
+  internal::LogMessage("./path/to/foo.cc", 123, MOJO_LOG_LEVEL_WARNING).stream()
+      << "hello " << "world";
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_WARNING, last_log_level());
+  EXPECT_EQ("foo.cc(123): hello world", last_message());
+
+  ResetMockLogger();
+
+  internal::LogMessage("/path/to/foo.cc", 123, MOJO_LOG_LEVEL_ERROR).stream()
+      << "hello " << "world";
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_ERROR, last_log_level());
+  EXPECT_EQ("foo.cc(123): hello world", last_message());
+
+  ResetMockLogger();
+
+  internal::LogMessage("path/to/foo.cc", 123, MOJO_LOG_LEVEL_FATAL).stream()
+      << "hello " << "world";
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_FATAL, last_log_level());
+  EXPECT_EQ("foo.cc(123): hello world", last_message());
+
+  ResetMockLogger();
+
+  internal::LogMessage(".\\xy\\foo.cc", 123, MOJO_LOG_LEVEL_VERBOSE).stream()
+      << "hello " << "world";
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_VERBOSE, last_log_level());
+  EXPECT_EQ("foo.cc(123): hello world", last_message());
+
+  ResetMockLogger();
+
+  internal::LogMessage("xy\\foo.cc", 123, MOJO_LOG_LEVEL_VERBOSE-1).stream()
+      << "hello " << "world";
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_VERBOSE-1, last_log_level());
+  EXPECT_EQ("foo.cc(123): hello world", last_message());
+
+  ResetMockLogger();
+
+  internal::LogMessage("C:\\xy\\foo.cc", 123, MOJO_LOG_LEVEL_VERBOSE-9).stream()
+      << "hello " << "world";
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_VERBOSE-9, last_log_level());
+  EXPECT_EQ("foo.cc(123): hello world", last_message());
+
+  ResetMockLogger();
+
+  internal::LogMessage(__FILE__, 123, MOJO_LOG_LEVEL_INFO).stream()
+      << "hello " << "world";
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_INFO, last_log_level());
+  EXPECT_EQ(OUR_FILENAME "(123): hello world", last_message());
+}
+
+TEST_F(LoggingTest, LogStream) {
+  MOJO_LOG_STREAM(INFO) << "hello";
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_INFO, last_log_level());
+  EXPECT_EQ(ExpectedLogMessage(__LINE__-3, "hello"), last_message());
+
+  ResetMockLogger();
+
+  MOJO_LOG_STREAM(ERROR) << "hi " << 123;
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_ERROR, last_log_level());
+  EXPECT_EQ(ExpectedLogMessage(__LINE__-3, "hi 123"), last_message());
+}
+
+TEST_F(LoggingTest, LazyLogStream) {
+  MOJO_LAZY_LOG_STREAM(INFO, true) << "hello";
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_INFO, last_log_level());
+  EXPECT_EQ(ExpectedLogMessage(__LINE__-3, "hello"), last_message());
+
+  ResetMockLogger();
+
+  MOJO_LAZY_LOG_STREAM(ERROR, true) << "hi " << 123;
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_ERROR, last_log_level());
+  EXPECT_EQ(ExpectedLogMessage(__LINE__-3, "hi 123"), last_message());
+
+  ResetMockLogger();
+
+  MOJO_LAZY_LOG_STREAM(INFO, false) << "hello";
+  EXPECT_FALSE(log_message_was_called());
+
+  ResetMockLogger();
+
+  MOJO_LAZY_LOG_STREAM(FATAL, false) << "hello";
+  EXPECT_FALSE(log_message_was_called());
+
+  ResetMockLogger();
+
+  bool x = false;
+  // This probably fails to compile if we forget to parenthesize the condition
+  // in the macro (= has low precedence, and needs an lvalue on the LHS).
+  MOJO_LAZY_LOG_STREAM(ERROR, x = true) << "hello";
+  EXPECT_TRUE(log_message_was_called());
+
+  ResetMockLogger();
+
+  MOJO_LAZY_LOG_STREAM(WARNING, x = false) << "hello";
+  EXPECT_FALSE(log_message_was_called());
+}
+
+TEST_F(LoggingTest, ShouldLog) {
+  // We start at |MOJO_LOG_LEVEL_INFO|.
+  EXPECT_FALSE(MOJO_SHOULD_LOG(VERBOSE));
+  EXPECT_TRUE(MOJO_SHOULD_LOG(INFO));
+  EXPECT_TRUE(MOJO_SHOULD_LOG(WARNING));
+  EXPECT_TRUE(MOJO_SHOULD_LOG(ERROR));
+  EXPECT_TRUE(MOJO_SHOULD_LOG(FATAL));
+
+  Environment::GetDefaultLogger()->SetMinimumLogLevel(MOJO_LOG_LEVEL_ERROR);
+  EXPECT_FALSE(MOJO_SHOULD_LOG(VERBOSE));
+  EXPECT_FALSE(MOJO_SHOULD_LOG(INFO));
+  EXPECT_FALSE(MOJO_SHOULD_LOG(WARNING));
+  EXPECT_TRUE(MOJO_SHOULD_LOG(ERROR));
+  EXPECT_TRUE(MOJO_SHOULD_LOG(FATAL));
+
+  Environment::GetDefaultLogger()->SetMinimumLogLevel(MOJO_LOG_LEVEL_VERBOSE-1);
+  EXPECT_TRUE(MOJO_SHOULD_LOG(VERBOSE));
+  EXPECT_TRUE(MOJO_SHOULD_LOG(INFO));
+  EXPECT_TRUE(MOJO_SHOULD_LOG(WARNING));
+  EXPECT_TRUE(MOJO_SHOULD_LOG(ERROR));
+  EXPECT_TRUE(MOJO_SHOULD_LOG(FATAL));
+}
+
+TEST_F(LoggingTest, Log) {
+  // We start at |MOJO_LOG_LEVEL_INFO|.
+  MOJO_LOG(VERBOSE) << "hello";
+  EXPECT_FALSE(log_message_was_called());
+
+  ResetMockLogger();
+
+  MOJO_LOG(INFO) << "hello";
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_INFO, last_log_level());
+  EXPECT_EQ(ExpectedLogMessage(__LINE__-3, "hello"), last_message());
+
+  ResetMockLogger();
+
+  MOJO_LOG(ERROR) << "hello";
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_ERROR, last_log_level());
+  EXPECT_EQ(ExpectedLogMessage(__LINE__-3, "hello"), last_message());
+
+  ResetMockLogger();
+
+  Environment::GetDefaultLogger()->SetMinimumLogLevel(MOJO_LOG_LEVEL_ERROR);
+
+  MOJO_LOG(VERBOSE) << "hello";
+  EXPECT_FALSE(log_message_was_called());
+
+  ResetMockLogger();
+
+  MOJO_LOG(INFO) << "hello";
+  EXPECT_FALSE(log_message_was_called());
+
+  ResetMockLogger();
+
+  MOJO_LOG(ERROR) << "hello";
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_ERROR, last_log_level());
+  EXPECT_EQ(ExpectedLogMessage(__LINE__-3, "hello"), last_message());
+}
+
+TEST_F(LoggingTest, LogIf) {
+  // We start at |MOJO_LOG_LEVEL_INFO|.
+  MOJO_LOG_IF(VERBOSE, true) << "hello";
+  EXPECT_FALSE(log_message_was_called());
+
+  ResetMockLogger();
+
+  MOJO_LOG_IF(VERBOSE, false) << "hello";
+  EXPECT_FALSE(log_message_was_called());
+
+  ResetMockLogger();
+
+  bool x = false;
+  // Also try to make sure that we parenthesize the condition properly.
+  MOJO_LOG_IF(INFO, x = true) << "hello";
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_INFO, last_log_level());
+  EXPECT_EQ(ExpectedLogMessage(__LINE__-3, "hello"), last_message());
+
+  ResetMockLogger();
+
+  MOJO_LOG_IF(INFO, x = false) << "hello";
+  EXPECT_FALSE(log_message_was_called());
+
+  ResetMockLogger();
+
+  Environment::GetDefaultLogger()->SetMinimumLogLevel(MOJO_LOG_LEVEL_ERROR);
+
+  ResetMockLogger();
+
+  MOJO_LOG_IF(INFO, 0 != 1) << "hello";
+  EXPECT_FALSE(log_message_was_called());
+
+  ResetMockLogger();
+
+  MOJO_LOG_IF(WARNING, 1+1 == 2) << "hello";
+  EXPECT_FALSE(log_message_was_called());
+
+  ResetMockLogger();
+
+  MOJO_LOG_IF(ERROR, 1*2 == 2) << "hello";
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_ERROR, last_log_level());
+  EXPECT_EQ(ExpectedLogMessage(__LINE__-3, "hello"), last_message());
+
+  ResetMockLogger();
+
+  MOJO_LOG_IF(FATAL, 1*2 == 3) << "hello";
+  EXPECT_FALSE(log_message_was_called());
+
+  ResetMockLogger();
+
+  // |MOJO_LOG_IF()| shouldn't evaluate its condition if the level is below the
+  // minimum.
+  MOJO_LOG_IF(INFO, NotCalled()) << "hello";
+  EXPECT_FALSE(log_message_was_called());
+}
+
+TEST_F(LoggingTest, Check) {
+  MOJO_CHECK(true) << "hello";
+  EXPECT_FALSE(log_message_was_called());
+
+  ResetMockLogger();
+
+  bool x = true;
+  // Also try to make sure that we parenthesize the condition properly.
+  MOJO_CHECK(x = false) << "hello";
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_FATAL, last_log_level());
+  // Different compilers have different ideas about the line number of a split
+  // line.
+  int line = __LINE__;
+  EXPECT_EQ(ExpectedLogMessage(line-5, "Check failed: x = false. hello"),
+            last_message());
+
+  ResetMockLogger();
+
+  // Also test a "naked" |MOJO_CHECK()|s.
+  MOJO_CHECK(1+2 == 3);
+  EXPECT_FALSE(log_message_was_called());
+}
+
+TEST_F(LoggingTest, Dlog) {
+  // We start at |MOJO_LOG_LEVEL_INFO|.
+  MOJO_DLOG(VERBOSE) << "hello";
+  EXPECT_FALSE(log_message_was_called());
+
+  ResetMockLogger();
+
+  MOJO_DLOG(INFO) << "hello";
+#ifdef NDEBUG
+  EXPECT_FALSE(log_message_was_called());
+#else
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_INFO, last_log_level());
+  EXPECT_EQ(ExpectedLogMessage(__LINE__-6, "hello"), last_message());
+#endif
+}
+
+TEST_F(LoggingTest, DlogIf) {
+  // We start at |MOJO_LOG_LEVEL_INFO|. It shouldn't evaluate the condition in
+  // this case.
+  MOJO_DLOG_IF(VERBOSE, NotCalled()) << "hello";
+  EXPECT_FALSE(log_message_was_called());
+
+  ResetMockLogger();
+
+  MOJO_DLOG_IF(INFO, 1 == 0) << "hello";
+  EXPECT_FALSE(log_message_was_called());
+
+  ResetMockLogger();
+
+  MOJO_DLOG_IF(INFO, 1 == 1) << "hello";
+#ifdef NDEBUG
+  EXPECT_FALSE(log_message_was_called());
+#else
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_INFO, last_log_level());
+  EXPECT_EQ(ExpectedLogMessage(__LINE__-6, "hello"), last_message());
+#endif
+
+  ResetMockLogger();
+
+  // |MOJO_DLOG_IF()| shouldn't compile its condition for non-debug builds.
+#ifndef NDEBUG
+  bool debug_only = true;
+#endif
+  MOJO_DLOG_IF(WARNING, debug_only) << "hello";
+#ifdef NDEBUG
+  EXPECT_FALSE(log_message_was_called());
+#else
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_WARNING, last_log_level());
+  EXPECT_EQ(ExpectedLogMessage(__LINE__-6, "hello"), last_message());
+#endif
+}
+
+TEST_F(LoggingTest, Dcheck) {
+  MOJO_DCHECK(true);
+  EXPECT_FALSE(log_message_was_called());
+
+  ResetMockLogger();
+
+  MOJO_DCHECK(true) << "hello";
+  EXPECT_FALSE(log_message_was_called());
+
+  ResetMockLogger();
+
+  // |MOJO_DCHECK()| should compile (but not evaluate) its condition even for
+  // non-debug builds. (Hopefully, we'll get an unused variable error if it
+  // fails to compile the condition.)
+  bool x = true;
+  MOJO_DCHECK(x = false) << "hello";
+#ifdef NDEBUG
+  EXPECT_FALSE(log_message_was_called());
+#else
+  EXPECT_TRUE(log_message_was_called());
+  EXPECT_EQ(MOJO_LOG_LEVEL_FATAL, last_log_level());
+  // Different compilers have different ideas about the line number of a split
+  // line.
+  int line = __LINE__;
+  EXPECT_EQ(ExpectedLogMessage(line-8, "Check failed: x = false. hello"),
+            last_message());
+#endif
+}
+
+}  // namespace
+}  // namespace mojo