Squashed 'third_party/google-glog/' content from commit 5d46e1b
Change-Id: I4d7d0b2759aa01069e6990109ae0f5f9897512c4
git-subtree-dir: third_party/google-glog
git-subtree-split: 5d46e1bcfc92bf06a9ca3b3f1c5bb1dc024d9ecd
diff --git a/src/stacktrace_libunwind-inl.h b/src/stacktrace_libunwind-inl.h
new file mode 100644
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--- /dev/null
+++ b/src/stacktrace_libunwind-inl.h
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+// Copyright (c) 2005 - 2007, Google Inc.
+// All rights reserved.
+//
+// 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 Google Inc. 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.
+//
+// Author: Arun Sharma
+//
+// Produce stack trace using libunwind
+
+#include "utilities.h"
+
+extern "C" {
+#define UNW_LOCAL_ONLY
+#include <libunwind.h>
+}
+#include "glog/raw_logging.h"
+#include "stacktrace.h"
+
+_START_GOOGLE_NAMESPACE_
+
+// Sometimes, we can try to get a stack trace from within a stack
+// trace, because libunwind can call mmap (maybe indirectly via an
+// internal mmap based memory allocator), and that mmap gets trapped
+// and causes a stack-trace request. If were to try to honor that
+// recursive request, we'd end up with infinite recursion or deadlock.
+// Luckily, it's safe to ignore those subsequent traces. In such
+// cases, we return 0 to indicate the situation.
+static bool g_now_entering = false;
+
+// If you change this function, also change GetStackFrames below.
+int GetStackTrace(void** result, int max_depth, int skip_count) {
+ void *ip;
+ int n = 0;
+ unw_cursor_t cursor;
+ unw_context_t uc;
+
+ if (sync_val_compare_and_swap(&g_now_entering, false, true)) {
+ return 0;
+ }
+
+ unw_getcontext(&uc);
+ RAW_CHECK(unw_init_local(&cursor, &uc) >= 0, "unw_init_local failed");
+ skip_count++; // Do not include the "GetStackTrace" frame
+
+ while (n < max_depth) {
+ int ret = unw_get_reg(&cursor, UNW_REG_IP, (unw_word_t *) &ip);
+ if (ret < 0)
+ break;
+ if (skip_count > 0) {
+ skip_count--;
+ } else {
+ result[n++] = ip;
+ }
+ ret = unw_step(&cursor);
+ if (ret <= 0)
+ break;
+ }
+
+ g_now_entering = false;
+ return n;
+}
+
+_END_GOOGLE_NAMESPACE_