75 lines
		
	
	
	
		
			3.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			75 lines
		
	
	
	
		
			3.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| // Copyright 2017 The Abseil Authors.
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| //
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| // Licensed under the Apache License, Version 2.0 (the "License");
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| // you may not use this file except in compliance with the License.
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| // You may obtain a copy of the License at
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| //
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| //      http://www.apache.org/licenses/LICENSE-2.0
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| //
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| // Unless required by applicable law or agreed to in writing, software
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| // distributed under the License is distributed on an "AS IS" BASIS,
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| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| // See the License for the specific language governing permissions and
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| // limitations under the License.
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| //
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| // Produces a stack trace for Windows.  Normally, one could use
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| // stacktrace_x86-inl.h or stacktrace_x86_64-inl.h -- and indeed, that
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| // should work for binaries compiled using MSVC in "debug" mode.
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| // However, in "release" mode, Windows uses frame-pointer
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| // optimization, which makes getting a stack trace very difficult.
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| //
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| // There are several approaches one can take.  One is to use Windows
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| // intrinsics like StackWalk64.  These can work, but have restrictions
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| // on how successful they can be.  Another attempt is to write a
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| // version of stacktrace_x86-inl.h that has heuristic support for
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| // dealing with FPO, similar to what WinDbg does (see
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| // http://www.nynaeve.net/?p=97).  There are (non-working) examples of
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| // these approaches, complete with TODOs, in stacktrace_win32-inl.h#1
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| //
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| // The solution we've ended up doing is to call the undocumented
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| // windows function RtlCaptureStackBackTrace, which probably doesn't
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| // work with FPO but at least is fast, and doesn't require a symbol
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| // server.
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| //
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| // This code is inspired by a patch from David Vitek:
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| //   http://code.google.com/p/google-perftools/issues/detail?id=83
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| 
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| #ifndef ABSL_DEBUGGING_INTERNAL_STACKTRACE_WIN32_INL_H_
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| #define ABSL_DEBUGGING_INTERNAL_STACKTRACE_WIN32_INL_H_
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| 
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| #include <windows.h>    // for GetProcAddress and GetModuleHandle
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| #include <cassert>
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| 
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| typedef USHORT NTAPI RtlCaptureStackBackTrace_Function(
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|     IN ULONG frames_to_skip,
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|     IN ULONG frames_to_capture,
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|     OUT PVOID *backtrace,
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|     OUT PULONG backtrace_hash);
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| 
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| // Load the function we need at static init time, where we don't have
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| // to worry about someone else holding the loader's lock.
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| static RtlCaptureStackBackTrace_Function* const RtlCaptureStackBackTrace_fn =
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|    (RtlCaptureStackBackTrace_Function*)
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|    GetProcAddress(GetModuleHandleA("ntdll.dll"), "RtlCaptureStackBackTrace");
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| 
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| template <bool IS_STACK_FRAMES, bool IS_WITH_CONTEXT>
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| static int UnwindImpl(void** result, int* sizes, int max_depth, int skip_count,
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|                       const void *ucp, int *min_dropped_frames) {
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|   int n = 0;
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|   if (!RtlCaptureStackBackTrace_fn) {
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|     // can't find a stacktrace with no function to call
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|   } else {
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|     n = (int)RtlCaptureStackBackTrace_fn(skip_count + 2, max_depth, result, 0);
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|   }
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|   if (IS_STACK_FRAMES) {
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|     // No implementation for finding out the stack frame sizes yet.
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|     memset(sizes, 0, sizeof(*sizes) * n);
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|   }
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|   if (min_dropped_frames != nullptr) {
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|     // Not implemented.
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|     *min_dropped_frames = 0;
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|   }
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|   return n;
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| }
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| 
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| #endif  // ABSL_DEBUGGING_INTERNAL_STACKTRACE_WIN32_INL_H_
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