| // |
| // Copyright 2022 The ANGLE Project Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| // |
| // backtrace_utils_android.cpp: |
| // Implements the functions related to the backtrace info class for Android platforms. |
| // |
| |
| #include "backtrace_utils.h" |
| |
| #include <dlfcn.h> |
| #include <unwind.h> |
| |
| namespace |
| { |
| |
| // Size limit for the backtrace obtained from the device. |
| constexpr uint32_t kMaxBacktraceSize = 16; |
| |
| struct UnwindCallbackFnState |
| { |
| UnwindCallbackFnState() : current(nullptr), end(nullptr) {} |
| UnwindCallbackFnState(void **current, void **end) : current(current), end(end) {} |
| void **current; |
| void **end; |
| }; |
| |
| // Unwind callback function, which is called until the end of stack is reached. |
| _Unwind_Reason_Code unwindCallbackFn(struct _Unwind_Context *context, void *args) |
| { |
| auto *state = reinterpret_cast<UnwindCallbackFnState *>(args); |
| |
| // Get the instruction pointer. |
| uintptr_t ip = _Unwind_GetIP(context); |
| if (ip == 0) |
| { |
| return _URC_NO_REASON; |
| } |
| |
| // The buffer is populated at the current location with the instruction pointer address. The |
| // current value is incremented to prepare for the next entry in the stack trace. Once "current" |
| // gets to "end", the callback should stop. |
| if (state->current == state->end) |
| { |
| return _URC_END_OF_STACK; |
| } |
| |
| *state->current++ = reinterpret_cast<void *>(ip); |
| return _URC_NO_REASON; |
| } |
| } // namespace |
| |
| namespace angle |
| { |
| |
| void BacktraceInfo::populateBacktraceInfo(void **stackAddressBuffer, size_t stackAddressCount) |
| { |
| ASSERT(mStackAddresses.empty() && mStackSymbols.empty()); |
| |
| for (size_t i = 0; i < stackAddressCount; i++) |
| { |
| void *stackAddr = stackAddressBuffer[i]; |
| mStackAddresses.push_back(stackAddr); |
| |
| // Get the symbol if possible. dladdr() returns 0 on failure. |
| Dl_info dlInfo; |
| if (dladdr(stackAddr, &dlInfo) != 0 && dlInfo.dli_sname) |
| { |
| mStackSymbols.emplace_back(dlInfo.dli_sname); |
| } |
| else |
| { |
| mStackSymbols.emplace_back("unknown_symbol"); |
| } |
| } |
| |
| ASSERT(mStackAddresses.size() == mStackSymbols.size()); |
| } |
| |
| BacktraceInfo getBacktraceInfo() |
| { |
| void *stackAddrBuffer[kMaxBacktraceSize]; |
| |
| UnwindCallbackFnState unwindFnState(stackAddrBuffer, stackAddrBuffer + kMaxBacktraceSize); |
| _Unwind_Backtrace(unwindCallbackFn, &unwindFnState); |
| |
| // The number of the collected IPs is shown by how far "current" has moved. |
| auto stackAddressCount = static_cast<size_t>(unwindFnState.current - stackAddrBuffer); |
| |
| BacktraceInfo backtraceInfo; |
| backtraceInfo.populateBacktraceInfo(stackAddrBuffer, stackAddressCount); |
| return backtraceInfo; |
| } |
| |
| // The following function has been defined in each platform separately. |
| // - void printBacktraceInfo(BacktraceInfo backtraceInfo); |
| |
| } // namespace angle |