Android: Add chrome-specific dynamic linker.

third_party/crazy_linker/crazy_linker/src/crazy_linker_debug.cpp

Index: third_party/crazy_linker/crazy_linker/src/crazy_linker_debug.cpp
diff --git a/third_party/crazy_linker/crazy_linker/src/crazy_linker_debug.cpp b/third_party/crazy_linker/crazy_linker/src/crazy_linker_debug.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..352fb7c5b6318de52d5dcf0a58d686e3f1f3a1b2
--- /dev/null
+++ b/third_party/crazy_linker/crazy_linker/src/crazy_linker_debug.cpp
@@ -0,0 +1,66 @@
+// 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];

[bulach, 2013/09/09 16:14:15]

is the stack big enough at this depth?
perhaps allocate this at the heap, or as a static buffer?

[digit1, 2013/09/10 09:23:30]

I have no reason to think that the stack would be limited here, but I've changed
this to a heap allocation.
static buffers play pretty bad with threads.

+  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