Android: Add chrome-specific dynamic linker.

base/android/linker/crazy_linker/src/crazy_linker_debug.cpp

+// Copyright (c) 2013 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 "crazy_linker_debug.h"
+
+#include <errno.h>
+#include <string.h>
+
+#ifdef __ANDROID__
+#include <android/log.h>
+#endif
+#include <stdarg.h>
+#include <stdio.h>
+
+namespace crazy {
+
+#if CRAZY_DEBUG
+
+namespace {
+
+void LogArgs(const char* fmt, va_list args, bool print_error, int error) {
+  char buffer[4096];
+  int ret;
+
+  ret = vsnprintf(buffer, sizeof(buffer), fmt, args);
+  if (ret >= static_cast<int>(sizeof(buffer)))
+    ret = static_cast<int>(sizeof(buffer)) - 1;
+
+  if (print_error) {
+    strlcat(buffer, ": ", sizeof(buffer));
+    strlcat(buffer, strerror(error), sizeof(buffer));
+  }
+
+  // First, send to stderr.
+  fprintf(stderr, "%.*s", ret, buffer);
+
+#ifdef __ANDROID__
+  // Then to the Android log.
+  __android_log_write(ANDROID_LOG_INFO, "crazy_linker", buffer);
+#endif
+}
+
+}  // namespace
+
+void Log(const char* fmt, ...) {
+  int old_errno = errno;
+  va_list args;
+  va_start(args, fmt);
+  LogArgs(fmt, args, false, -1);
+  va_end(args);
+  errno = old_errno;
+}
+
+void LogErrno(const char* fmt, ...) {
+  int old_errno = errno;
+  va_list args;
+  va_start(args, fmt);
+  LogArgs(fmt, args, true, old_errno);
+  va_end(args);
+  errno = old_errno;
+}
+
+#endif  // CRAZY_DEBUG
+
+}  // namespace crazy