// 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.
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// 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 libgcc
extern "C" {
#include <stdlib.h> // for NULL
#include <unwind.h> // ABI defined unwinder
}
#include "stacktrace.h"
_START_GOOGLE_NAMESPACE_
typedef struct {
void **result;
int max_depth;
int skip_count;
int count;
} trace_arg_t;
// Workaround for the malloc() in _Unwind_Backtrace() issue.
static _Unwind_Reason_Code nop_backtrace(struct _Unwind_Context *uc, void *opq) {
return _URC_NO_REASON;
}
// This code is not considered ready to run until
// static initializers run so that we are guaranteed
// that any malloc-related initialization is done.
static bool ready_to_run = false;
class StackTraceInit {
public:
StackTraceInit() {
// Extra call to force initialization
_Unwind_Backtrace(nop_backtrace, NULL);
ready_to_run = true;
}
};
static StackTraceInit module_initializer; // Force initialization
static _Unwind_Reason_Code GetOneFrame(struct _Unwind_Context *uc, void *opq) {
trace_arg_t *targ = (trace_arg_t *) opq;
if (targ->skip_count > 0) {
targ->skip_count--;
} else {
targ->result[targ->count++] = (void *) _Unwind_GetIP(uc);
}
if (targ->count == targ->max_depth)
return _URC_END_OF_STACK;
return _URC_NO_REASON;
}
// If you change this function, also change GetStackFrames below.
int GetStackTrace(void** result, int max_depth, int skip_count) {
if (!ready_to_run)
return 0;
trace_arg_t targ;
skip_count += 1; // Do not include the "GetStackTrace" frame
targ.result = result;
targ.max_depth = max_depth;
targ.skip_count = skip_count;
targ.count = 0;
_Unwind_Backtrace(GetOneFrame, &targ);
return targ.count;
}
_END_GOOGLE_NAMESPACE_
