Squash: Fix bugs

trunk/3rdparty/gperftools-2-fit/src/stacktrace_libgcc-inl.h

@@ -0,0 +1,111 @@
+// -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*-
+// Copyright (c) 2016, gperftools Contributors
+// 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.
+
+// This file implements backtrace capturing via libgcc's
+// _Unwind_Backtrace. This generally works almost always. It will fail
+// sometimes when we're trying to capture backtrace from signal
+// handler (i.e. in cpu profiler) while some C++ code is throwing
+// exception.
+
+#ifndef BASE_STACKTRACE_LIBGCC_INL_H_
+#define BASE_STACKTRACE_LIBGCC_INL_H_
+// Note: this file is included into stacktrace.cc more than once.
+// Anything that should only be defined once should be here:
+
+extern "C" {
+#include <assert.h>
+#include <string.h>   // for memset()
+}
+
+#include <unwind.h>
+
+#include "gperftools/stacktrace.h"
+
+struct libgcc_backtrace_data {
+  void **array;
+  int skip;
+  int pos;
+  int limit;
+};
+
+static _Unwind_Reason_Code libgcc_backtrace_helper(struct _Unwind_Context *ctx,
+                                                   void *_data) {
+  libgcc_backtrace_data *data =
+    reinterpret_cast<libgcc_backtrace_data *>(_data);
+
+  if (data->skip > 0) {
+    data->skip--;
+    return _URC_NO_REASON;
+  }
+
+  if (data->pos < data->limit) {
+    void *ip = reinterpret_cast<void *>(_Unwind_GetIP(ctx));;
+    data->array[data->pos++] = ip;
+  }
+
+  return _URC_NO_REASON;
+}
+
+#endif  // BASE_STACKTRACE_LIBGCC_INL_H_
+
+// Note: this part of the file is included several times.
+// Do not put globals below.
+
+// The following 4 functions are generated from the code below:
+//   GetStack{Trace,Frames}()
+//   GetStack{Trace,Frames}WithContext()
+//
+// These functions take the following args:
+//   void** result: the stack-trace, as an array
+//   int* sizes: the size of each stack frame, as an array
+//               (GetStackFrames* only)
+//   int max_depth: the size of the result (and sizes) array(s)
+//   int skip_count: how many stack pointers to skip before storing in result
+//   void* ucp: a ucontext_t* (GetStack{Trace,Frames}WithContext only)
+static int GET_STACK_TRACE_OR_FRAMES {
+  libgcc_backtrace_data data;
+  data.array = result;
+  // we're also skipping current and parent's frame
+  data.skip = skip_count + 2;
+  data.pos = 0;
+  data.limit = max_depth;
+
+  _Unwind_Backtrace(libgcc_backtrace_helper, &data);
+
+  if (data.pos > 1 && data.array[data.pos - 1] == NULL)
+    --data.pos;
+
+#if IS_STACK_FRAMES
+  // No implementation for finding out the stack frame sizes.
+  memset(sizes, 0, sizeof(*sizes) * data.pos);
+#endif
+
+  return data.pos;
+}