stacktrace_win32-inl.inc (4054B)
1 // Copyright 2017 The Abseil Authors. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 // 15 // Produces a stack trace for Windows. Normally, one could use 16 // stacktrace_x86-inl.h or stacktrace_x86_64-inl.h -- and indeed, that 17 // should work for binaries compiled using MSVC in "debug" mode. 18 // However, in "release" mode, Windows uses frame-pointer 19 // optimization, which makes getting a stack trace very difficult. 20 // 21 // There are several approaches one can take. One is to use Windows 22 // intrinsics like StackWalk64. These can work, but have restrictions 23 // on how successful they can be. Another attempt is to write a 24 // version of stacktrace_x86-inl.h that has heuristic support for 25 // dealing with FPO, similar to what WinDbg does (see 26 // http://www.nynaeve.net/?p=97). There are (non-working) examples of 27 // these approaches, complete with TODOs, in stacktrace_win32-inl.h#1 28 // 29 // The solution we've ended up doing is to call the undocumented 30 // windows function RtlCaptureStackBackTrace, which probably doesn't 31 // work with FPO but at least is fast, and doesn't require a symbol 32 // server. 33 // 34 // This code is inspired by a patch from David Vitek: 35 // https://code.google.com/p/google-perftools/issues/detail?id=83 36 37 #ifndef ABSL_DEBUGGING_INTERNAL_STACKTRACE_WIN32_INL_H_ 38 #define ABSL_DEBUGGING_INTERNAL_STACKTRACE_WIN32_INL_H_ 39 40 #include <windows.h> // for GetProcAddress and GetModuleHandle 41 #include <cassert> 42 43 typedef USHORT NTAPI RtlCaptureStackBackTrace_Function( 44 IN ULONG frames_to_skip, 45 IN ULONG frames_to_capture, 46 OUT PVOID *backtrace, 47 OUT PULONG backtrace_hash); 48 49 // It is not possible to load RtlCaptureStackBackTrace at static init time in 50 // UWP. CaptureStackBackTrace is the public version of RtlCaptureStackBackTrace 51 #if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP) && \ 52 !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP) 53 static RtlCaptureStackBackTrace_Function* const RtlCaptureStackBackTrace_fn = 54 &::CaptureStackBackTrace; 55 #else 56 // Load the function we need at static init time, where we don't have 57 // to worry about someone else holding the loader's lock. 58 static RtlCaptureStackBackTrace_Function* const RtlCaptureStackBackTrace_fn = 59 (RtlCaptureStackBackTrace_Function*)GetProcAddress( 60 GetModuleHandleA("ntdll.dll"), "RtlCaptureStackBackTrace"); 61 #endif // WINAPI_PARTITION_APP && !WINAPI_PARTITION_DESKTOP 62 63 template <bool IS_STACK_FRAMES, bool IS_WITH_CONTEXT> 64 static int UnwindImpl(void** result, uintptr_t* frames, int* sizes, 65 int max_depth, int skip_count, const void*, 66 int* min_dropped_frames) { 67 USHORT n = 0; 68 if (!RtlCaptureStackBackTrace_fn || skip_count < 0 || max_depth < 0) { 69 // can't get a stacktrace with no function/invalid args 70 } else { 71 n = RtlCaptureStackBackTrace_fn(static_cast<ULONG>(skip_count) + 2, 72 static_cast<ULONG>(max_depth), result, 0); 73 } 74 if (IS_STACK_FRAMES) { 75 // No implementation for finding out the stack frames yet. 76 if (frames != nullptr) { 77 memset(frames, 0, sizeof(*frames) * n); 78 } 79 if (sizes != nullptr) { 80 memset(sizes, 0, sizeof(*sizes) * n); 81 } 82 } 83 if (min_dropped_frames != nullptr) { 84 // Not implemented. 85 *min_dropped_frames = 0; 86 } 87 return n; 88 } 89 90 namespace absl { 91 ABSL_NAMESPACE_BEGIN 92 namespace debugging_internal { 93 bool StackTraceWorksForTest() { 94 return false; 95 } 96 } // namespace debugging_internal 97 ABSL_NAMESPACE_END 98 } // namespace absl 99 100 #endif // ABSL_DEBUGGING_INTERNAL_STACKTRACE_WIN32_INL_H_