1 // 2 // Copyright 2018 The Abseil Authors. 3 // 4 // Licensed under the Apache License, Version 2.0 (the "License"); 5 // you may not use this file except in compliance with the License. 6 // You may obtain a copy of the License at 7 // 8 // https://www.apache.org/licenses/LICENSE-2.0 9 // 10 // Unless required by applicable law or agreed to in writing, software 11 // distributed under the License is distributed on an "AS IS" BASIS, 12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 // See the License for the specific language governing permissions and 14 // limitations under the License. 15 // 16 17 #ifndef ABSL_DEBUGGING_INTERNAL_EXAMINE_STACK_H_ 18 #define ABSL_DEBUGGING_INTERNAL_EXAMINE_STACK_H_ 19 20 #include "absl/base/config.h" 21 22 namespace absl { 23 ABSL_NAMESPACE_BEGIN 24 namespace debugging_internal { 25 26 // Type of function used for printing in stack trace dumping, etc. 27 // We avoid closures to keep things simple. 28 typedef void OutputWriter(const char*, void*); 29 30 // RegisterDebugStackTraceHook() allows to register a single routine 31 // `hook` that is called each time DumpStackTrace() is called. 32 // `hook` may be called from a signal handler. 33 typedef void (*SymbolizeUrlEmitter)(void* const stack[], int depth, 34 OutputWriter* writer, void* writer_arg); 35 36 // Registration of SymbolizeUrlEmitter for use inside of a signal handler. 37 // This is inherently unsafe and must be signal safe code. 38 void RegisterDebugStackTraceHook(SymbolizeUrlEmitter hook); 39 SymbolizeUrlEmitter GetDebugStackTraceHook(); 40 41 // Returns the program counter from signal context, or nullptr if 42 // unknown. `vuc` is a ucontext_t*. We use void* to avoid the use of 43 // ucontext_t on non-POSIX systems. 44 void* GetProgramCounter(void* const vuc); 45 46 // Uses `writer` to dump the program counter, stack trace, and stack 47 // frame sizes. 48 void DumpPCAndFrameSizesAndStackTrace(void* const pc, void* const stack[], 49 int frame_sizes[], int depth, 50 int min_dropped_frames, 51 bool symbolize_stacktrace, 52 OutputWriter* writer, void* writer_arg); 53 54 // Dump current stack trace omitting the topmost `min_dropped_frames` stack 55 // frames. 56 void DumpStackTrace(int min_dropped_frames, int max_num_frames, 57 bool symbolize_stacktrace, OutputWriter* writer, 58 void* writer_arg); 59 60 } // namespace debugging_internal 61 ABSL_NAMESPACE_END 62 } // namespace absl 63 64 #endif // ABSL_DEBUGGING_INTERNAL_EXAMINE_STACK_H_ 65