From d8723cca95018f8949fa469f1e1ea7b899a336ba Mon Sep 17 00:00:00 2001 From: punkrockguy318 Date: Fri, 15 Mar 2013 19:31:39 +0000 Subject: [PATCH] add backward-cpp header (missed it in previous commit) --- trunk/src/utils/backward.hpp | 2169 ++++++++++++++++++++++++++++++++++ 1 file changed, 2169 insertions(+) create mode 100644 trunk/src/utils/backward.hpp diff --git a/trunk/src/utils/backward.hpp b/trunk/src/utils/backward.hpp new file mode 100644 index 00000000..612765fe --- /dev/null +++ b/trunk/src/utils/backward.hpp @@ -0,0 +1,2169 @@ +/* + * backward.hpp + * Copyright © 2013 François-Xavier 'Bombela' Bourlet + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#ifndef H_6B9572DA_A64B_49E6_B234_051480991C89 +#define H_6B9572DA_A64B_49E6_B234_051480991C89 + +#ifndef __cplusplus +# error "It's not going to compile without a C++ compiler..." +#endif + +#if defined(BACKWARD_CXX11) +#elif defined(BACKWARD_CXX98) +#else +# if __cplusplus >= 201103L +# define BACKWARD_CXX11 +# else +# define BACKWARD_CXX98 +# endif +#endif + +// You can define one of the following (or leave it to the auto-detection): +// +// #define BACKWARD_SYSTEM_LINUX +// - specialization for linux +// +// #define BACKWARD_SYSTEM_UNKNOWN +// - placebo implementation, does nothing. +// +#if defined(BACKWARD_SYSTEM_LINUX) +#elif defined(BACKWARD_SYSTEM_UNKNOWN) +#else +# if defined(__linux) +# define BACKWARD_SYSTEM_LINUX +# else +# define BACKWARD_SYSTEM_UNKNOWN +# endif +#endif + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#if defined(BACKWARD_SYSTEM_LINUX) + +// On linux, backtrace can back-trace or "walk" the stack using the following +// library: +// +// #define BACKWARD_HAS_UNWIND 1 +// - unwind comes from libgcc, but I saw an equivalent inside clang itself. +// - with unwind, the stacktrace is as accurate as it can possibly be, since +// this is used by the C++ runtine in gcc/clang for stack unwinding on +// exception. +// - normally libgcc is already linked to your program by default. +// +// #define BACKWARD_HAS_BACKTRACE == 1 +// - backtrace seems to be a little bit more portable than libunwind, but on +// linux, it uses unwind anyway, but abstract away a tiny information that is +// sadly really important in order to get perfectly accurate stack traces. +// - backtrace is part of the (e)glib library. +// +// The default is: +// #define BACKWARD_HAS_UNWIND == 1 +// +# if BACKWARD_HAS_UNWIND == 1 +# elif BACKWARD_HAS_BACKTRACE == 1 +# else +# undef BACKWARD_HAS_UNWIND +# define BACKWARD_HAS_UNWIND 1 +# undef BACKWARD_HAS_BACKTRACE +# define BACKWARD_HAS_BACKTRACE 0 +# endif + +// On linux, backward can extract detailed information about a stack trace +// using one of the following library: +// +// #define BACKWARD_HAS_DW 1 +// - libdw gives you the most juicy details out of your stack traces: +// - object filename +// - function name +// - source filename +// - line and column numbers +// - source code snippet (assuming the file is accessible) +// - variables name and values (if not optimized out) +// - You need to link with the lib "dw": +// - apt-get install libdw-dev +// - g++/clang++ -ldw ... +// +// #define BACKWARD_HAS_BFD 1 +// - With libbfd, you get a fair about of details: +// - object filename +// - function name +// - source filename +// - line numbers +// - source code snippet (assuming the file is accessible) +// - You need to link with the lib "bfd": +// - apt-get install binutils-dev +// - g++/clang++ -lbfd ... +// +// #define BACKWARD_HAS_BACKTRACE_SYMBOL 1 +// - backtrace provides minimal details for a stack trace: +// - object filename +// - function name +// - backtrace is part of the (e)glib library. +// +// The default is: +// #define BACKWARD_HAS_BACKTRACE_SYMBOL == 1 +// +# if BACKWARD_HAS_DW == 1 +# elif BACKWARD_HAS_BFD == 1 +# elif BACKWARD_HAS_BACKTRACE_SYMBOL == 1 +# else +# undef BACKWARD_HAS_DW +# define BACKWARD_HAS_DW 0 +# undef BACKWARD_HAS_BFD +# define BACKWARD_HAS_BFD 0 +# undef BACKWARD_HAS_BACKTRACE_SYMBOL +# define BACKWARD_HAS_BACKTRACE_SYMBOL 1 +# endif + + +# if BACKWARD_HAS_UNWIND == 1 +# include +# endif + +# include +# include +# include +# include +# include +# include +# include + +# if BACKWARD_HAS_BFD == 1 +# include +# ifndef _GNU_SOURCE +# define _GNU_SOURCE +# include +# undef _GNU_SOURCE +# else +# include +# endif +# endif + +# if BACKWARD_HAS_DW == 1 +# include +# include +# include +# endif + +# if (BACKWARD_HAS_BACKTRACE == 1) || (BACKWARD_HAS_BACKTRACE_SYMBOL == 1) + // then we shall rely on backtrace +# include +# endif + +#endif // defined(BACKWARD_SYSTEM_LINUX) + +#if defined(BACKWARD_CXX11) +# include +# include // for std::swap + namespace backward { + namespace details { + template + struct hashtable { + typedef std::unordered_map type; + }; + using std::move; + } // namespace details + } // namespace backward +#elif defined(BACKWARD_CXX98) +# include + namespace backward { + namespace details { + template + struct hashtable { + typedef std::map type; + }; + template + const T& move(const T& v) { return v; } + template + T& move(T& v) { return v; } + } // namespace details + } // namespace backward +#else +# error "Mmm if its not C++11 nor C++98... go play in the toaster." +#endif + +namespace backward { + +namespace system_tag { + struct linux_tag; // seems that I cannot call that "linux" because the name + // is already defined... so I am adding _tag everywhere. + struct unknown_tag; + +#if defined(BACKWARD_SYSTEM_LINUX) + typedef linux_tag current_tag; +#elif defined(BACKWARD_SYSTEM_UNKNOWN) + typedef unknown_tag current_tag; +#else +# error "May I please get my system defines?" +#endif +} // namespace system_tag + + +namespace stacktrace_tag { +#ifdef BACKWARD_SYSTEM_LINUX + struct unwind; + struct backtrace; + +# if BACKWARD_HAS_UNWIND == 1 + typedef unwind currnet; +# elif BACKWARD_HAS_BACKTRACE == 1 + typedef backtrace current; +# else +# error "I know it's difficult but you need to make a choice!" +# endif +#endif // BACKWARD_SYSTEM_LINUX +} // namespace stacktrace_tag + + +namespace trace_resolver_tag { +#ifdef BACKWARD_SYSTEM_LINUX + struct libdw; + struct libbfd; + struct backtrace_symbol; + +# if BACKWARD_HAS_DW == 1 + typedef libdw current; +# elif BACKWARD_HAS_BFD == 1 + typedef libbfd current; +# elif BACKWARD_HAS_BACKTRACE_SYMBOL == 1 + typedef backtrace_symbol current; +# else +# error "You shall not pass, until you know what you want." +# endif +#endif // BACKWARD_SYSTEM_LINUX +} // namespace trace_resolver_tag + +namespace details { + +template + struct rm_ptr { typedef T type; }; + +template + struct rm_ptr { typedef T type; }; + +template + struct rm_ptr { typedef const T type; }; + +template +struct deleter { + template + void operator()(U& ptr) const { + (*F)(ptr); + } +}; + +template +struct default_delete { + void operator()(T& ptr) const { + delete ptr; + } +}; + +template > +class handle { + struct dummy; + T _val; + bool _empty; + +#if defined(BACKWARD_CXX11) + handle(const handle&) = delete; + handle& operator=(const handle&) = delete; +#endif + +public: + ~handle() { + if (not _empty) { + Deleter()(_val); + } + } + + explicit handle(): _val(), _empty(true) {} + explicit handle(T val): _val(val), _empty(false) {} + +#if defined(BACKWARD_CXX11) + handle(handle&& from): _empty(true) { + swap(from); + } + handle& operator=(handle&& from) { + swap(from); return *this; + } +#else + explicit handle(const handle& from): _empty(true) { + // some sort of poor man's move semantic. + swap(const_cast(from)); + } + handle& operator=(const handle& from) { + // some sort of poor man's move semantic. + swap(const_cast(from)); return *this; + } +#endif + + void reset(T new_val) { + handle tmp(new_val); + swap(tmp); + } + operator const dummy*() const { + if (_empty) { + return 0; + } + return reinterpret_cast(_val); + } + T get() { + return _val; + } + T release() { + _empty = true; + return _val; + } + void swap(handle& b) { + using std::swap; + swap(b._val, _val); // can throw, we are safe here. + swap(b._empty, _empty); // should not throw: if you cannot swap two + // bools without throwing... It's a lost cause anyway! + } + + T operator->() { return _val; } + const T operator->() const { return _val; } + + typedef typename rm_ptr::type& ref_t; + ref_t operator*() { return *_val; } + const ref_t operator*() const { return *_val; } + ref_t operator[](size_t idx) { return _val[idx]; } + + // Watch out, we've got a badass over here + T* operator&() { + _empty = false; + return &_val; + } +}; + +} // namespace details + +/*************** A TRACE ***************/ + +struct Trace { + void* addr; + size_t idx; + + Trace(): + addr(0), idx(0) {} + + explicit Trace(void* addr, size_t idx): + addr(addr), idx(idx) {} +}; + +// Really simple, generic, and dumb representation of a variable. +// A variable has a name and can represent either: +// - a value (as a string) +// - a list of values (a list of strings) +// - a map of values (a list of variable) +class Variable { +public: + enum Kind { VALUE, LIST, MAP }; + + typedef std::vector list_t; + typedef std::vector map_t; + + std::string name; + Kind kind; + + Variable(Kind k): kind(k) { + switch (k) { + case VALUE: + new (&storage) std::string(); + break; + + case LIST: + new (&storage) list_t(); + break; + + case MAP: + new (&storage) map_t(); + break; + } + } + + std::string& value() { + return reinterpret_cast(storage); + } + list_t& list() { + return reinterpret_cast(storage); + } + map_t& map() { + return reinterpret_cast(storage); + } + + + const std::string& value() const { + return reinterpret_cast(storage); + } + const list_t& list() const { + return reinterpret_cast(storage); + } + const map_t& map() const { + return reinterpret_cast(storage); + } + +private: + // the C++98 style union for non-trivial objects, yes yes I know, its not + // aligned as good as it can be, blabla... Screw this. + union { + char s1[sizeof (std::string)]; + char s2[sizeof (list_t)]; + char s3[sizeof (map_t)]; + } storage; +}; + +struct TraceWithLocals: public Trace { + // Locals variable and values. + std::vector locals; + + TraceWithLocals(): Trace() {} + TraceWithLocals(const Trace& mini_trace): + Trace(mini_trace) {} +}; + +struct ResolvedTrace: public TraceWithLocals { + + struct SourceLoc { + std::string function; + std::string filename; + size_t line; + size_t col; + + SourceLoc(): line(0), col(0) {} + + bool operator==(const SourceLoc& b) const { + return function == b.function + and filename == b.filename + and line == b.line + and col == b.col; + } + + bool operator!=(const SourceLoc& b) const { + return not (*this == b); + } + }; + + // In which binary object this trace is located. + std::string object_filename; + + // The function in the object that contain the trace. This is not the same + // as source.function which can be an function inlined in object_function. + std::string object_function; + + // The source location of this trace. It is possible for filename to be + // empty and for line/col to be invalid (value 0) if this information + // couldn't be deduced, for example if there is no debug information in the + // binary object. + SourceLoc source; + + // An optionals list of "inliners". All the successive sources location + // from where the source location of the trace (the attribute right above) + // is inlined. It is especially useful when you compiled with optimization. + typedef std::vector source_locs_t; + source_locs_t inliners; + + ResolvedTrace(const Trace& mini_trace): + TraceWithLocals(mini_trace) {} + ResolvedTrace(const TraceWithLocals& mini_trace_with_locals): + TraceWithLocals(mini_trace_with_locals) {} +}; + +/*************** STACK TRACE ***************/ + +// default implemention. +template +class StackTraceImpl { +public: + size_t size() const { return 0; } + Trace operator[](size_t) { return Trace(); } + size_t load_here(size_t=0) { return 0; } + size_t load_from(void*, size_t=0) { return 0; } + size_t thread_id() const { return 0; } +}; + +#ifdef BACKWARD_SYSTEM_LINUX + +class StackTraceLinuxImplBase { +public: + StackTraceLinuxImplBase(): _thread_id(0), _skip(0) {} + + size_t thread_id() const { + return _thread_id; + } + +protected: + void load_thread_info() { + _thread_id = syscall(SYS_gettid); + if (_thread_id == (size_t) getpid()) { + // If the thread is the main one, let's hide that. + // I like to keep little secret sometimes. + _thread_id = 0; + } + } + + void skip_n_firsts(size_t n) { _skip = n; } + size_t skip_n_firsts() const { return _skip; } + +private: + size_t _thread_id; + size_t _skip; +}; + +class StackTraceLinuxImplHolder: public StackTraceLinuxImplBase { +public: + size_t size() const { + return _stacktrace.size() ? _stacktrace.size() - skip_n_firsts() : 0; + } + Trace operator[](size_t idx) { + if (idx >= size()) { + return Trace(); + } + return Trace(_stacktrace[idx + skip_n_firsts()], idx); + } + void** begin() { + if (size()) { + return &_stacktrace[skip_n_firsts()]; + } + return 0; + } + +protected: + std::vector _stacktrace; +}; + + +#if BACKWARD_HAS_UNWIND == 1 + +namespace details { + +template +class Unwinder { +public: + size_t operator()(F& f, size_t depth) { + _f = &f; + _index = -1; + _depth = depth; + _Unwind_Backtrace(&this->backtrace_trampoline, this); + return _index; + } + +private: + F* _f; + ssize_t _index; + size_t _depth; + + static _Unwind_Reason_Code backtrace_trampoline( + _Unwind_Context* ctx, void *self) { + return ((Unwinder*)self)->backtrace(ctx); + } + + _Unwind_Reason_Code backtrace(_Unwind_Context* ctx) { + if (_index >= 0 and static_cast(_index) >= _depth) + return _URC_END_OF_STACK; + + int ip_before_instruction = 0; + uintptr_t ip = _Unwind_GetIPInfo(ctx, &ip_before_instruction); + + if (not ip_before_instruction) { + ip -= 1; + } + + if (_index >= 0) { // ignore first frame. + (*_f)(_index, (void*)ip); + } + _index += 1; + return _URC_NO_REASON; + } +}; + +template +size_t unwind(F f, size_t depth) { + Unwinder unwinder; + return unwinder(f, depth); +} + +} // namespace details + + +template <> +class StackTraceImpl: public StackTraceLinuxImplHolder { +public: + __attribute__ ((noinline)) // TODO use some macro + size_t load_here(size_t depth=32) { + load_thread_info(); + if (depth == 0) { + return 0; + } + _stacktrace.resize(depth); + size_t trace_cnt = details::unwind(callback(*this), depth); + _stacktrace.resize(trace_cnt); + skip_n_firsts(0); + return size(); + } + size_t load_from(void* addr, size_t depth=32) { + load_here(depth + 8); + + for (size_t i = 0; i < _stacktrace.size(); ++i) { + if (_stacktrace[i] == addr) { + skip_n_firsts(i); + break; + } + } + + _stacktrace.resize(std::min(_stacktrace.size(), + skip_n_firsts() + depth)); + return size(); + } + +private: + struct callback { + StackTraceImpl& self; + callback(StackTraceImpl& self): self(self) {} + + void operator()(size_t idx, void* addr) { + self._stacktrace[idx] = addr; + } + }; +}; + + +#else // BACKWARD_HAS_UNWIND == 0 + +template <> +class StackTraceImpl: public StackTraceLinuxImplHolder { +public: + __attribute__ ((noinline)) // TODO use some macro + size_t load_here(size_t depth=32) { + load_thread_info(); + if (depth == 0) { + return 0; + } + _stacktrace.resize(depth + 1); + size_t trace_cnt = backtrace(&_stacktrace[0], _stacktrace.size()); + _stacktrace.resize(trace_cnt); + skip_n_firsts(1); + return size(); + } + + size_t load_from(void* addr, size_t depth=32) { + load_here(depth + 8); + + for (size_t i = 0; i < _stacktrace.size(); ++i) { + if (_stacktrace[i] == addr) { + skip_n_firsts(i); + _stacktrace[i] = (void*)( (uintptr_t)_stacktrace[i] + 1); + break; + } + } + + _stacktrace.resize(std::min(_stacktrace.size(), + skip_n_firsts() + depth)); + return size(); + } +}; + +#endif // BACKWARD_HAS_UNWIND +#endif // BACKWARD_SYSTEM_LINUX + +class StackTrace: + public StackTraceImpl {}; + +/*********** STACKTRACE WITH LOCALS ***********/ + +// default implemention. +template +class StackTraceWithLocalsImpl: + public StackTrace {}; + +#ifdef BACKWARD_SYSTEM_LINUX +#if BACKWARD_HAS_UNWIND +#if BACKWARD_HAS_DW + +template <> +class StackTraceWithLocalsImpl: + public StackTraceLinuxImplBase { +public: + __attribute__ ((noinline)) // TODO use some macro + size_t load_here(size_t depth=32) { + load_thread_info(); + if (depth == 0) { + return 0; + } + _stacktrace.resize(depth); + size_t trace_cnt = details::unwind(callback(*this), depth); + _stacktrace.resize(trace_cnt); + skip_n_firsts(0); + return size(); + } + size_t load_from(void* addr, size_t depth=32) { + load_here(depth + 8); + + for (size_t i = 0; i < _stacktrace.size(); ++i) { + if (_stacktrace[i].addr == addr) { + skip_n_firsts(i); + break; + } + } + _stacktrace.resize(std::min(_stacktrace.size(), + skip_n_firsts() + depth)); + return size(); + } + size_t size() const { + return _stacktrace.size() ? _stacktrace.size() - skip_n_firsts() : 0; + } + const TraceWithLocals& operator[](size_t idx) { + if (idx >= size()) { + return _nil_trace; + } + return _stacktrace[idx + skip_n_firsts()]; + } + +private: + std::vector _stacktrace; + TraceWithLocals _nil_trace; + + void resolve_trace(TraceWithLocals& trace) { + Variable v(Variable::VALUE); + v.name = "var"; + v.value() = "42"; + trace.locals.push_back(v); + } + + struct callback { + StackTraceWithLocalsImpl& self; + callback(StackTraceWithLocalsImpl& self): self(self) {} + + void operator()(size_t idx, void* addr) { + self._stacktrace[idx].addr = addr; + self.resolve_trace(self._stacktrace[idx]); + } + }; +}; + +#endif // BACKWARD_HAS_DW +#endif // BACKWARD_HAS_UNWIND +#endif // BACKWARD_SYSTEM_LINUX + +class StackTraceWithLocals: + public StackTraceWithLocalsImpl {}; + +/*************** TRACE RESOLVER ***************/ + +template +class TraceResolverImpl; + +#ifdef BACKWARD_SYSTEM_UNKNOWN + +template <> +class TraceResolverImpl { +public: + template + void load_stacktrace(ST&) {} + ResolvedTrace resolve(ResolvedTrace t) { + return t; + } +}; + +#endif + +#ifdef BACKWARD_SYSTEM_LINUX + +class TraceResolverLinuxImplBase { +protected: + std::string demangle(const char* funcname) { + using namespace details; + _demangle_buffer.reset( + abi::__cxa_demangle(funcname, _demangle_buffer.release(), + &_demangle_buffer_length, 0) + ); + if (_demangle_buffer) { + return _demangle_buffer.get(); + } + return funcname; + } + +private: + details::handle _demangle_buffer; + size_t _demangle_buffer_length; +}; + +template +class TraceResolverLinuxImpl; + +#if BACKWARD_HAS_BACKTRACE_SYMBOL == 1 + +template <> +class TraceResolverLinuxImpl: + public TraceResolverLinuxImplBase { +public: + template + void load_stacktrace(ST& st) { + using namespace details; + if (st.size() == 0) { + return; + } + _symbols.reset( + backtrace_symbols(st.begin(), st.size()) + ); + } + + ResolvedTrace resolve(ResolvedTrace trace) { + char* filename = _symbols[trace.idx]; + char* funcname = filename; + while (*funcname && *funcname != '(') { + funcname += 1; + } + trace.object_filename.assign(filename, funcname++); + char* funcname_end = funcname; + while (*funcname_end && *funcname_end != ')' && *funcname_end != '+') { + funcname_end += 1; + } + *funcname_end = '\0'; + trace.object_function = this->demangle(funcname); + trace.source.function = trace.object_function; // we cannot do better. + return trace; + } + +private: + details::handle _symbols; +}; + +#endif // BACKWARD_HAS_BACKTRACE_SYMBOL == 1 + +#if BACKWARD_HAS_BFD == 1 + +template <> +class TraceResolverLinuxImpl: + public TraceResolverLinuxImplBase { +public: + TraceResolverLinuxImpl(): _bfd_loaded(false) {} + + template + void load_stacktrace(ST&) {} + + ResolvedTrace resolve(ResolvedTrace trace) { + Dl_info symbol_info; + + // trace.addr is a virtual address in memory pointing to some code. + // Let's try to find from which loaded object it comes from. + // The loaded object can be yourself btw. + if (not dladdr(trace.addr, &symbol_info)) { + return trace; // dat broken trace... + } + + // Now we get in symbol_info: + // .dli_fname: + // pathname of the shared object that contains the address. + // .dli_fbase: + // where the object is loaded in memory. + // .dli_sname: + // the name of the nearest symbol to trace.addr, we expect a + // function name. + // .dli_saddr: + // the exact address corresponding to .dli_sname. + + if (symbol_info.dli_sname) { + trace.object_function = demangle(symbol_info.dli_sname); + } + + if (not symbol_info.dli_fname) { + return trace; + } + + trace.object_filename = symbol_info.dli_fname; + bfd_fileobject& fobj = load_object_with_bfd(symbol_info.dli_fname); + if (not fobj.handle) { + return trace; // sad, we couldn't load the object :( + } + + + find_sym_result* details_selected; // to be filled. + + // trace.addr is the next instruction to be executed after returning + // from the nested stack frame. In C++ this usually relate to the next + // statement right after the function call that leaded to a new stack + // frame. This is not usually what you want to see when printing out a + // stacktrace... + find_sym_result details_call_site = find_symbol_details(fobj, + trace.addr, symbol_info.dli_fbase); + details_selected = &details_call_site; + +#if BACKWARD_HAS_UNWIND == 0 + // ...this is why we also try to resolve the symbol that is right + // before the return address. If we are lucky enough, we will get the + // line of the function that was called. But if the code is optimized, + // we might get something absolutely not related since the compiler + // can reschedule the return address with inline functions and + // tail-call optimisation (among other things that I don't even know + // or cannot even dream about with my tiny limited brain). + find_sym_result details_adjusted_call_site = find_symbol_details(fobj, + (void*) (uintptr_t(trace.addr) - 1), + symbol_info.dli_fbase); + + // In debug mode, we should always get the right thing(TM). + if (details_call_site.found and details_adjusted_call_site.found) { + // Ok, we assume that details_adjusted_call_site is a better estimation. + details_selected = &details_adjusted_call_site; + trace.addr = (void*) (uintptr_t(trace.addr) - 1); + } + + if (details_selected == &details_call_site and details_call_site.found) { + // we have to re-resolve the symbol in order to reset some + // internal state in BFD... so we can call backtrace_inliners + // thereafter... + details_call_site = find_symbol_details(fobj, trace.addr, + symbol_info.dli_fbase); + } +#endif // BACKWARD_HAS_UNWIND + + if (details_selected->found) { + if (details_selected->filename) { + trace.source.filename = details_selected->filename; + } + trace.source.line = details_selected->line; + + if (details_selected->funcname) { + // this time we get the name of the function where the code is + // located, instead of the function were the address is + // located. In short, if the code was inlined, we get the + // function correspoding to the code. Else we already got in + // trace.function. + trace.source.function = demangle(details_selected->funcname); + + if (not symbol_info.dli_sname) { + // for the case dladdr failed to find the symbol name of + // the function, we might as well try to put something + // here. + trace.object_function = trace.source.function; + } + } + + // Maybe the source of the trace got inlined inside the function + // (trace.source.function). Let's see if we can get all the inlined + // calls along the way up to the initial call site. + trace.inliners = backtrace_inliners(fobj, *details_selected); + +#if 0 + if (trace.inliners.size() == 0) { + // Maybe the trace was not inlined... or maybe it was and we + // are lacking the debug information. Let's try to make the + // world better and see if we can get the line number of the + // function (trace.source.function) now. + // + // We will get the location of where the function start (to be + // exact: the first instruction that really start the + // function), not where the name of the function is defined. + // This can be quite far away from the name of the function + // btw. + // + // If the source of the function is the same as the source of + // the trace, we cannot say if the trace was really inlined or + // not. However, if the filename of the source is different + // between the function and the trace... we can declare it as + // an inliner. This is not 100% accurate, but better than + // nothing. + + if (symbol_info.dli_saddr) { + find_sym_result details = find_symbol_details(fobj, + symbol_info.dli_saddr, + symbol_info.dli_fbase); + + if (details.found) { + ResolvedTrace::SourceLoc diy_inliner; + diy_inliner.line = details.line; + if (details.filename) { + diy_inliner.filename = details.filename; + } + if (details.funcname) { + diy_inliner.function = demangle(details.funcname); + } else { + diy_inliner.function = trace.source.function; + } + if (diy_inliner != trace.source) { + trace.inliners.push_back(diy_inliner); + } + } + } + } +#endif + } + + return trace; + } + +private: + bool _bfd_loaded; + + typedef details::handle + > bfd_handle_t; + + typedef details::handle bfd_symtab_t; + + + struct bfd_fileobject { + bfd_handle_t handle; + bfd_vma base_addr; + bfd_symtab_t symtab; + bfd_symtab_t dynamic_symtab; + }; + + typedef typename details::hashtable::type + fobj_bfd_map_t; + fobj_bfd_map_t _fobj_bfd_map; + + bfd_fileobject& load_object_with_bfd(const std::string& filename_object) { + using namespace details; + + if (not _bfd_loaded) { + using namespace details; + bfd_init(); + _bfd_loaded = true; + } + + typename fobj_bfd_map_t::iterator it = + _fobj_bfd_map.find(filename_object); + if (it != _fobj_bfd_map.end()) { + return it->second; + } + + // this new object is empty for now. + bfd_fileobject& r = _fobj_bfd_map[filename_object]; + + // we do the work temporary in this one; + bfd_handle_t bfd_handle; + + int fd = open(filename_object.c_str(), O_RDONLY); + bfd_handle.reset( + bfd_fdopenr(filename_object.c_str(), "default", fd) + ); + if (not bfd_handle) { + close(fd); + return r; + } + + if (not bfd_check_format(bfd_handle.get(), bfd_object)) { + return r; // not an object? You lose. + } + + if ((bfd_get_file_flags(bfd_handle.get()) & HAS_SYMS) == 0) { + return r; // that's what happen when you forget to compile in debug. + } + + ssize_t symtab_storage_size = + bfd_get_symtab_upper_bound(bfd_handle.get()); + + ssize_t dyn_symtab_storage_size = + bfd_get_dynamic_symtab_upper_bound(bfd_handle.get()); + + if (symtab_storage_size <= 0 and dyn_symtab_storage_size <= 0) { + return r; // weird, is the file is corrupted? + } + + bfd_symtab_t symtab, dynamic_symtab; + ssize_t symcount = 0, dyn_symcount = 0; + + if (symtab_storage_size > 0) { + symtab.reset( + (bfd_symbol**) malloc(symtab_storage_size) + ); + symcount = bfd_canonicalize_symtab( + bfd_handle.get(), symtab.get() + ); + } + + if (dyn_symtab_storage_size > 0) { + dynamic_symtab.reset( + (bfd_symbol**) malloc(dyn_symtab_storage_size) + ); + dyn_symcount = bfd_canonicalize_dynamic_symtab( + bfd_handle.get(), dynamic_symtab.get() + ); + } + + + if (symcount <= 0 and dyn_symcount <= 0) { + return r; // damned, that's a stripped file that you got there! + } + + r.handle = move(bfd_handle); + r.symtab = move(symtab); + r.dynamic_symtab = move(dynamic_symtab); + return r; + } + + struct find_sym_result { + bool found; + const char* filename; + const char* funcname; + unsigned int line; + }; + + struct find_sym_context { + TraceResolverLinuxImpl* self; + bfd_fileobject* fobj; + void* addr; + void* base_addr; + find_sym_result result; + }; + + find_sym_result find_symbol_details(bfd_fileobject& fobj, void* addr, + void* base_addr) { + find_sym_context context; + context.self = this; + context.fobj = &fobj; + context.addr = addr; + context.base_addr = base_addr; + context.result.found = false; + bfd_map_over_sections(fobj.handle.get(), &find_in_section_trampoline, + (void*)&context); + return context.result; + } + + static void find_in_section_trampoline(bfd*, asection* section, + void* data) { + find_sym_context* context = static_cast(data); + context->self->find_in_section( + reinterpret_cast(context->addr), + reinterpret_cast(context->base_addr), + *context->fobj, + section, context->result + ); + } + + void find_in_section(bfd_vma addr, bfd_vma base_addr, + bfd_fileobject& fobj, asection* section, find_sym_result& result) + { + if (result.found) return; + + if ((bfd_get_section_flags(fobj.handle.get(), section) + & SEC_ALLOC) == 0) + return; // a debug section is never loaded automatically. + + bfd_vma sec_addr = bfd_get_section_vma(fobj.handle.get(), section); + bfd_size_type size = bfd_get_section_size(section); + + // are we in the boundaries of the section? + if (addr < sec_addr or addr >= sec_addr + size) { + addr -= base_addr; // oups, a relocated object, lets try again... + if (addr < sec_addr or addr >= sec_addr + size) { + return; + } + } + + if (not result.found and fobj.symtab) { + result.found = bfd_find_nearest_line(fobj.handle.get(), section, + fobj.symtab.get(), addr - sec_addr, &result.filename, + &result.funcname, &result.line); + } + + if (not result.found and fobj.dynamic_symtab) { + result.found = bfd_find_nearest_line(fobj.handle.get(), section, + fobj.dynamic_symtab.get(), addr - sec_addr, + &result.filename, &result.funcname, &result.line); + } + + } + + ResolvedTrace::source_locs_t backtrace_inliners(bfd_fileobject& fobj, + find_sym_result previous_result) { + // This function can be called ONLY after a SUCCESSFUL call to + // find_symbol_details. The state is global to the bfd_handle. + ResolvedTrace::source_locs_t results; + while (previous_result.found) { + find_sym_result result; + result.found = bfd_find_inliner_info(fobj.handle.get(), + &result.filename, &result.funcname, &result.line); + + if (result.found) /* and not ( + cstrings_eq(previous_result.filename, result.filename) + and cstrings_eq(previous_result.funcname, result.funcname) + and result.line == previous_result.line + )) */ { + ResolvedTrace::SourceLoc src_loc; + src_loc.line = result.line; + if (result.filename) { + src_loc.filename = result.filename; + } + if (result.funcname) { + src_loc.function = demangle(result.funcname); + } + results.push_back(src_loc); + } + previous_result = result; + } + return results; + } + + bool cstrings_eq(const char* a, const char* b) { + if (not a or not b) { + return false; + } + return strcmp(a, b) == 0; + } + +}; +#endif // BACKWARD_HAS_BFD == 1 + +#if BACKWARD_HAS_DW == 1 + +template <> +class TraceResolverLinuxImpl: + public TraceResolverLinuxImplBase { +public: + TraceResolverLinuxImpl(): _dwfl_handle_initialized(false) {} + + template + void load_stacktrace(ST&) {} + + ResolvedTrace resolve(ResolvedTrace trace) { + using namespace details; + + Dwarf_Addr trace_addr = (Dwarf_Addr) trace.addr; + + if (not _dwfl_handle_initialized) { + // initialize dwfl... + _dwfl_cb.reset(new Dwfl_Callbacks); + _dwfl_cb->find_elf = &dwfl_linux_proc_find_elf; + _dwfl_cb->find_debuginfo = &dwfl_standard_find_debuginfo; + _dwfl_cb->debuginfo_path = 0; + + _dwfl_handle.reset(dwfl_begin(_dwfl_cb.get())); + _dwfl_handle_initialized = true; + + if (not _dwfl_handle) { + return trace; + } + + // ...from the current process. + dwfl_report_begin(_dwfl_handle.get()); + int r = dwfl_linux_proc_report (_dwfl_handle.get(), getpid()); + dwfl_report_end(_dwfl_handle.get(), NULL, NULL); + if (r < 0) { + return trace; + } + } + + if (not _dwfl_handle) { + return trace; + } + + // find the module (binary object) that contains the trace's address. + // This is not using any debug information, but the addresses ranges of + // all the currently loaded binary object. + Dwfl_Module* mod = dwfl_addrmodule(_dwfl_handle.get(), trace_addr); + if (mod) { + // now that we found it, lets get the name of it, this will be the + // full path to the running binary or one of the loaded library. + const char* module_name = dwfl_module_info (mod, + 0, 0, 0, 0, 0, 0, 0); + if (module_name) { + trace.object_filename = module_name; + } + // We also look after the name of the symbol, equal or before this + // address. This is found by walking the symtab. We should get the + // symbol corresponding to the function (mangled) containing the + // address. If the code corresponding to the address was inlined, + // this is the name of the out-most inliner function. + const char* sym_name = dwfl_module_addrname(mod, trace_addr); + if (sym_name) { + trace.object_function = demangle(sym_name); + } + } + + // now let's get serious, and find out the source location (file and + // line number) of the address. + + // This function will look in .debug_aranges for the address and map it + // to the location of the compilation unit DIE in .debug_info and + // return it. + Dwarf_Addr mod_bias = 0; + Dwarf_Die* cudie = dwfl_module_addrdie(mod, trace_addr, &mod_bias); + +#if 1 + if (not cudie) { + // Sadly clang does not generate the section .debug_aranges, thus + // dwfl_module_addrdie will fail early. Clang doesn't either set + // the lowpc/highpc/range info for every compilation unit. + // + // So in order to save the world: + // for every compilation unit, we will iterate over every single + // DIEs. Normally functions should have a lowpc/highpc/range, which + // we will use to infer the compilation unit. + + // note that this is probably badly inefficient. + while ((cudie = dwfl_module_nextcu(mod, cudie, &mod_bias))) { + Dwarf_Die die_mem; + Dwarf_Die* fundie = find_fundie_by_pc(cudie, + trace_addr - mod_bias, &die_mem); + if (fundie) { + break; + } + } + } +#endif + +//#define BACKWARD_I_DO_NOT_RECOMMEND_TO_ENABLE_THIS_HORRIBLE_PIECE_OF_CODE +#ifdef BACKWARD_I_DO_NOT_RECOMMEND_TO_ENABLE_THIS_HORRIBLE_PIECE_OF_CODE + if (not cudie) { + // If it's still not enough, lets dive deeper in the shit, and try + // to save the world again: for every compilation unit, we will + // load the corresponding .debug_line section, and see if we can + // find our address in it. + + Dwarf_Addr cfi_bias; + Dwarf_CFI* cfi_cache = dwfl_module_eh_cfi(mod, &cfi_bias); + + Dwarf_Addr bias; + while ((cudie = dwfl_module_nextcu(mod, cudie, &bias))) { + if (dwarf_getsrc_die(cudie, trace_addr - bias)) { + + // ...but if we get a match, it might be a false positive + // because our (address - bias) might as well be valid in a + // different compilation unit. So we throw our last card on + // the table and lookup for the address into the .eh_frame + // section. + + handle frame; + dwarf_cfi_addrframe(cfi_cache, trace_addr - cfi_bias, &frame); + if (frame) { + break; + } + } + } + } +#endif + + if (not cudie) { + return trace; // this time we lost the game :/ + } + + // Now that we have a compilation unit DIE, this function will be able + // to load the corresponding section in .debug_line (if not already + // loaded) and hopefully find the source location mapped to our + // address. + Dwarf_Line* srcloc = dwarf_getsrc_die(cudie, trace_addr - mod_bias); + + if (srcloc) { + const char* srcfile = dwarf_linesrc(srcloc, 0, 0); + if (srcfile) { + trace.source.filename = srcfile; + } + int line = 0, col = 0; + dwarf_lineno(srcloc, &line); + dwarf_linecol(srcloc, &col); + trace.source.line = line; + trace.source.col = col; + } + + deep_first_search_by_pc(cudie, trace_addr - mod_bias, + inliners_search_cb(trace)); + if (trace.source.function.size() == 0) { + // fallback. + trace.source.function = trace.object_function; + } + + return trace; + } + +private: + typedef details::handle > + dwfl_handle_t; + details::handle > + _dwfl_cb; + dwfl_handle_t _dwfl_handle; + bool _dwfl_handle_initialized; + + // defined here because in C++98, template function cannot take locally + // defined types... grrr. + struct inliners_search_cb { + void operator()(Dwarf_Die* die) { + switch (dwarf_tag(die)) { + case DW_TAG_subprogram: + trace.source.function = dwarf_diename(die)?:""; + break; + + case DW_TAG_inlined_subroutine: + ResolvedTrace::SourceLoc sloc; + Dwarf_Attribute attr_mem; + + sloc.function = dwarf_diename(die)?:""; + sloc.filename = die_call_file(die)?:""; + + Dwarf_Word line = 0, col = 0; + dwarf_formudata(dwarf_attr(die, DW_AT_call_line, + &attr_mem), &line); + dwarf_formudata(dwarf_attr(die, DW_AT_call_column, + &attr_mem), &col); + sloc.line = line; + sloc.col = col; + + trace.inliners.push_back(sloc); + break; + }; + } + ResolvedTrace& trace; + inliners_search_cb(ResolvedTrace& t): trace(t) {} + }; + + + static bool die_has_pc(Dwarf_Die* die, Dwarf_Addr pc) { + Dwarf_Addr low, high; + + // continuous range + if (dwarf_hasattr(die, DW_AT_low_pc) and + dwarf_hasattr(die, DW_AT_high_pc)) { + if (dwarf_lowpc(die, &low) != 0) { + return false; + } + if (dwarf_highpc(die, &high) != 0) { + Dwarf_Attribute attr_mem; + Dwarf_Attribute* attr = dwarf_attr(die, DW_AT_high_pc, &attr_mem); + Dwarf_Word value; + if (dwarf_formudata(attr, &value) != 0) { + return false; + } + high = low + value; + } + return pc >= low and pc < high; + } + + // non-continuous range. + Dwarf_Addr base; + ptrdiff_t offset = 0; + while ((offset = dwarf_ranges(die, offset, &base, &low, &high)) > 0) { + if (pc >= low and pc < high) { + return true; + } + } + return false; + } + + static Dwarf_Die* find_fundie_by_pc(Dwarf_Die* parent_die, Dwarf_Addr pc, + Dwarf_Die* result) { + if (dwarf_child(parent_die, result) != 0) { + return 0; + } + + Dwarf_Die* die = result; + do { + switch (dwarf_tag(die)) { + case DW_TAG_subprogram: + case DW_TAG_inlined_subroutine: + if (die_has_pc(die, pc)) { + return result; + } + default: + bool declaration = false; + Dwarf_Attribute attr_mem; + dwarf_formflag(dwarf_attr(die, DW_AT_declaration, + &attr_mem), &declaration); + if (not declaration) { + // let's be curious and look deeper in the tree, + // function are not necessarily at the first level, but + // might be nested inside a namespace, structure etc. + Dwarf_Die die_mem; + Dwarf_Die* indie = find_fundie_by_pc(die, pc, &die_mem); + if (indie) { + *result = die_mem; + return result; + } + } + }; + } while (dwarf_siblingof(die, result) == 0); + return 0; + } + + template + static bool deep_first_search_by_pc(Dwarf_Die* parent_die, + Dwarf_Addr pc, CB cb) { + Dwarf_Die die_mem; + if (dwarf_child(parent_die, &die_mem) != 0) { + return false; + } + + bool branch_has_pc = false; + Dwarf_Die* die = &die_mem; + do { + bool declaration = false; + Dwarf_Attribute attr_mem; + dwarf_formflag(dwarf_attr(die, DW_AT_declaration, &attr_mem), &declaration); + if (not declaration) { + // let's be curious and look deeper in the tree, function are + // not necessarily at the first level, but might be nested + // inside a namespace, structure, a function, an inlined + // function etc. + branch_has_pc = deep_first_search_by_pc(die, pc, cb); + } + if (not branch_has_pc) { + branch_has_pc = die_has_pc(die, pc); + } + if (branch_has_pc) { + cb(die); + } + } while (dwarf_siblingof(die, &die_mem) == 0); + return branch_has_pc; + } + + static const char* die_call_file(Dwarf_Die *die) { + Dwarf_Attribute attr_mem; + Dwarf_Sword file_idx = 0; + + dwarf_formsdata(dwarf_attr(die, DW_AT_call_file, &attr_mem), + &file_idx); + + if (file_idx == 0) { + return 0; + } + + Dwarf_Die die_mem; + Dwarf_Die* cudie = dwarf_diecu(die, &die_mem, 0, 0); + if (not cudie) { + return 0; + } + + Dwarf_Files* files = 0; + size_t nfiles; + dwarf_getsrcfiles(cudie, &files, &nfiles); + if (not files) { + return 0; + } + + return dwarf_filesrc(files, file_idx, 0, 0); + } + +}; +#endif // BACKWARD_HAS_DW == 1 + +template<> +class TraceResolverImpl: + public TraceResolverLinuxImpl {}; + +#endif // BACKWARD_SYSTEM_LINUX + +class TraceResolver: + public TraceResolverImpl {}; + +/*************** CODE SNIPPET ***************/ + +class SourceFile { +public: + typedef std::vector > lines_t; + + SourceFile() {} + SourceFile(const std::string& path): _file(new std::ifstream(path.c_str())) {} + bool is_open() const { return _file->is_open(); } + + lines_t& get_lines(size_t line_start, size_t line_count, lines_t& lines) { + using namespace std; + // This function make uses of the dumbest algo ever: + // 1) seek(0) + // 2) read lines one by one and discard until line_start + // 3) read line one by one until line_start + line_count + // + // If you are getting snippets many time from the same file, it is + // somewhat a waste of CPU, feel free to benchmark and propose a + // better solution ;) + + _file->clear(); + _file->seekg(0); + string line; + size_t line_idx; + + for (line_idx = 1; line_idx < line_start; ++line_idx) { + getline(*_file, line); + if (not *_file) { + return lines; + } + } + + // think of it like a lambda in C++98 ;) + // but look, I will reuse it two times! + // What a good boy am I. + struct isspace { + bool operator()(char c) { + return std::isspace(c); + } + }; + + bool started = false; + for (; line_idx < line_start + line_count; ++line_idx) { + getline(*_file, line); + if (not *_file) { + return lines; + } + if (not started) { + if (std::find_if(line.begin(), line.end(), + not_isspace()) == line.end()) + continue; + started = true; + } + lines.push_back(make_pair(line_idx, line)); + } + + lines.erase( + std::find_if(lines.rbegin(), lines.rend(), + not_isempty()).base(), lines.end() + ); + return lines; + } + + lines_t get_lines(size_t line_start, size_t line_count) { + lines_t lines; + return get_lines(line_start, line_count, lines); + } + + // there is no find_if_not in C++98, lets do something crappy to + // workaround. + struct not_isspace { + bool operator()(char c) { + return not std::isspace(c); + } + }; + // and define this one here because C++98 is not happy with local defined + // struct passed to template functions, fuuuu. + struct not_isempty { + bool operator()(const lines_t::value_type& p) { + return not (std::find_if(p.second.begin(), p.second.end(), + not_isspace()) == p.second.end()); + } + }; + + void swap(SourceFile& b) { + _file.swap(b._file); + } + +#if defined(BACKWARD_CXX11) + SourceFile(SourceFile&& from): _file(0) { + swap(from); + } + SourceFile& operator=(SourceFile&& from) { + swap(from); return *this; + } +#else + explicit SourceFile(const SourceFile& from) { + // some sort of poor man's move semantic. + swap(const_cast(from)); + } + SourceFile& operator=(const SourceFile& from) { + // some sort of poor man's move semantic. + swap(const_cast(from)); return *this; + } +#endif + +private: + details::handle + > _file; + +#if defined(BACKWARD_CXX11) + SourceFile(const SourceFile&) = delete; + SourceFile& operator=(const SourceFile&) = delete; +#endif +}; + +class SnippetFactory { +public: + typedef SourceFile::lines_t lines_t; + + lines_t get_snippet(const std::string& filename, + size_t line_start, size_t context_size) { + + SourceFile& src_file = get_src_file(filename); + size_t start = line_start - context_size / 2; + return src_file.get_lines(start, context_size); + } + + lines_t get_combined_snippet( + const std::string& filename_a, size_t line_a, + const std::string& filename_b, size_t line_b, + size_t context_size) { + SourceFile& src_file_a = get_src_file(filename_a); + SourceFile& src_file_b = get_src_file(filename_b); + + lines_t lines = src_file_a.get_lines(line_a - context_size / 4, + context_size / 2); + src_file_b.get_lines(line_b - context_size / 4, context_size / 2, + lines); + return lines; + } + + lines_t get_coalesced_snippet(const std::string& filename, + size_t line_a, size_t line_b, size_t context_size) { + SourceFile& src_file = get_src_file(filename); + + using std::min; using std::max; + size_t a = min(line_a, line_b); + size_t b = max(line_a, line_b); + + if ((b - a) < (context_size / 3)) { + return src_file.get_lines((a + b - context_size + 1) / 2, + context_size); + } + + lines_t lines = src_file.get_lines(a - context_size / 4, + context_size / 2); + src_file.get_lines(b - context_size / 4, context_size / 2, lines); + return lines; + } + + +private: + typedef details::hashtable::type src_files_t; + src_files_t _src_files; + + SourceFile& get_src_file(const std::string& filename) { + src_files_t::iterator it = _src_files.find(filename); + if (it != _src_files.end()) { + return it->second; + } + SourceFile& new_src_file = _src_files[filename]; + new_src_file = SourceFile(filename); + return new_src_file; + } +}; + +/*************** PRINTER ***************/ + +#ifdef BACKWARD_SYSTEM_LINUX + +namespace Color { + enum type { + yellow = 33, + purple = 35, + reset = 39 + }; +} // namespace Color + +class Colorize { +public: + Colorize(std::FILE* os): + _os(os), _reset(false), _istty(false) {} + + void init() { + _istty = isatty(fileno(_os)); + } + + void set_color(Color::type ccode) { + if (not _istty) return; + + // I assume that the terminal can handle basic colors. Seriously I + // don't want to deal with all the termcap shit. + fprintf(_os, "\033[%im", static_cast(ccode)); + _reset = (ccode != Color::reset); + } + + ~Colorize() { + if (_reset) { + set_color(Color::reset); + } + } + +private: + std::FILE* _os; + bool _reset; + bool _istty; +}; + +#else // ndef BACKWARD_SYSTEM_LINUX + + +namespace Color { + enum type { + yellow = 0, + purple = 0, + reset = 0 + }; +} // namespace Color + +class Colorize { +public: + Colorize(std::FILE*) {} + void init(); + void set_color(Color::type) {} +}; + +#endif // BACKWARD_SYSTEM_LINUX + +class Printer { +public: + bool snippet; + bool color; + bool address; + bool object; + + Printer(): + snippet(true), + color(true), + address(false), + object(false) + {} + + template + FILE* print(StackTrace& st, FILE* os = stderr) { + using namespace std; + + Colorize colorize(os); + if (color) { + colorize.init(); + } + + fprintf(os, "Stack trace (most recent call last)"); + if (st.thread_id()) { + fprintf(os, " in thread %zi:\n", st.thread_id()); + } else { + fprintf(os, ":\n"); + } + + _resolver.load_stacktrace(st); + for (size_t trace_idx = st.size(); trace_idx > 0; --trace_idx) { + fprintf(os, "#%-2zi", trace_idx); + bool already_indented = true; + const ResolvedTrace trace = _resolver.resolve(st[trace_idx-1]); + + if (not trace.source.filename.size() or object) { + fprintf(os, " Object \"%s\", at %p, in %s\n", + trace.object_filename.c_str(), trace.addr, + trace.object_function.c_str()); + already_indented = false; + } + + if (trace.source.filename.size()) { + for (size_t inliner_idx = trace.inliners.size(); + inliner_idx > 0; --inliner_idx) { + if (not already_indented) { + fprintf(os, " "); + } + const ResolvedTrace::SourceLoc& inliner_loc + = trace.inliners[inliner_idx-1]; + print_source_loc(os, " | ", inliner_loc); + if (snippet) { + print_snippet(os, " | ", inliner_loc, + colorize, Color::purple, 5); + } + already_indented = false; + } + + if (not already_indented) { + fprintf(os, " "); + } + print_source_loc(os, " ", trace.source, trace.addr); + if (snippet) { + print_snippet(os, " ", trace.source, + colorize, Color::yellow, 7); + } + + if (trace.locals.size()) { + print_locals(os, " ", trace.locals); + } + } + } + return os; + } +private: + TraceResolver _resolver; + SnippetFactory _snippets; + + void print_snippet(FILE* os, const char* indent, + const ResolvedTrace::SourceLoc& source_loc, + Colorize& colorize, Color::type color_code, + int context_size) + { + using namespace std; + typedef SnippetFactory::lines_t lines_t; + + lines_t lines = _snippets.get_snippet(source_loc.filename, + source_loc.line, context_size); + + for (lines_t::const_iterator it = lines.begin(); + it != lines.end(); ++it) { + if (it-> first == source_loc.line) { + colorize.set_color(color_code); + fprintf(os, "%s>", indent); + } else { + fprintf(os, "%s ", indent); + } + fprintf(os, "%4li: %s\n", it->first, it->second.c_str()); + if (it-> first == source_loc.line) { + colorize.set_color(Color::reset); + } + } + } + + void print_source_loc(FILE* os, const char* indent, + const ResolvedTrace::SourceLoc& source_loc, + void* addr=0) { + fprintf(os, "%sSource \"%s\", line %zi, in %s", + indent, source_loc.filename.c_str(), source_loc.line, + source_loc.function.c_str()); + + if (address and addr != 0) { + fprintf(os, " [%p]\n", addr); + } else { + fprintf(os, "\n"); + } + } + + void print_var(FILE* os, const char* base_indent, int indent, + const Variable& var) { + fprintf(os, "%s%s: ", base_indent, var.name.c_str()); + switch (var.kind) { + case Variable::VALUE: + fprintf(os, "%s\n", var.value().c_str()); + break; + case Variable::LIST: + fprintf(os, "["); + for (size_t i = 0; i < var.list().size(); ++i) { + if (i > 0) { + fprintf(os, ", %s", var.list()[i].c_str()); + } + fprintf(os, "%s", var.list()[i].c_str()); + } + fprintf(os, "]\n"); + break; + case Variable::MAP: + fprintf(os, "{\n"); + for (size_t i = 0; i < var.map().size(); ++i) { + if (i > 0) { + fprintf(os, ",\n%s", base_indent); + } + print_var(os, base_indent, indent + 2, var.map()[i]); + } + fprintf(os, "]\n"); + break; + }; + } + + void print_locals(FILE* os, const char* indent, + const std::vector& locals) { + fprintf(os, "%sLocal variables:\n", indent); + for (size_t i = 0; i < locals.size(); ++i) { + if (i > 0) { + fprintf(os, ",\n%s", indent); + } + print_var(os, indent, 0, locals[i]); + } + } +}; + +/*************** SIGNALS HANDLING ***************/ + +#ifdef BACKWARD_SYSTEM_LINUX + +class SignalHandling { +public: + SignalHandling(): _loaded(false) { + // TODO: add a signal dedicated stack, so we can handle stack-overflow. + bool success = true; + const int signals[] = { + // default action: Core + SIGILL, + SIGABRT, + SIGFPE, + SIGSEGV, + SIGBUS, + + // I am not sure the following signals should be enabled by + // default: + + // default action: Term + SIGHUP, + SIGINT, + SIGPIPE, + SIGALRM, + SIGTERM, + SIGUSR1, + SIGUSR2, + SIGPOLL, + SIGPROF, + SIGVTALRM, + SIGIO, + SIGPWR, + + // default action: Core + SIGQUIT, + SIGSYS, + SIGTRAP, + SIGXCPU, + SIGXFSZ + }; + for (const int* sig = signals; + sig != signals + sizeof signals / sizeof *signals; ++sig) { + + struct sigaction action; + action.sa_flags = SA_SIGINFO; + sigemptyset(&action.sa_mask); + action.sa_sigaction = &sig_handler; + + int r = sigaction(*sig, &action, 0); + if (r < 0) success = false; + } + _loaded = success; + } + + bool loaded() const { return _loaded; } + +private: + bool _loaded; + + static void sig_handler(int, siginfo_t* info, void* _ctx) { + ucontext_t *uctx = (ucontext_t*) _ctx; + + StackTrace st; + void* error_addr = 0; +#ifdef REG_RIP // x86_64 + error_addr = reinterpret_cast(uctx->uc_mcontext.gregs[REG_RIP]); +#elif defined(REG_EIP) // x86_32 + error_addr = reinterpret_cast(uctx->uc_mcontext.gregs[REG_EIP]); +#else +# warning ":/ sorry, ain't know no nothing none not of your architecture!" +#endif + if (error_addr) { + st.load_from(error_addr, 32); + } else { + st.load_here(32); + } + + Printer printer; + printer.address = true; + printer.print(st, stderr); + + psiginfo(info, 0); + exit(EXIT_FAILURE); + } +}; + +#endif // BACKWARD_SYSTEM_LINUX + +#ifdef BACKWARD_SYSTEM_UNKNOWN + +class SignalHandling { +public: + SignalHandling() {} + bool init() { return false; } +}; + +#endif // BACKWARD_SYSTEM_UNKNOWN + +#if 0 +void crit_err_hdlr(int sig_num, siginfo_t * info, void * ucontext) +{ + void * array[50]; + void * caller_address; + char ** messages; + int size, i; + sig_ucontext_t * uc; + + uc = (sig_ucontext_t *)ucontext; + + /* Get the address at the time the signal was raised from the EIP (x86) */ + caller_address = (void *) uc->uc_mcontext.eip; + + fprintf(stderr, "signal %d (%s), address is %p from %p\n", + sig_num, strsignal(sig_num), info->si_addr, + (void *)caller_address); + + size = backtrace(array, 50); + + /* overwrite sigaction with caller's address */ + array[1] = caller_address; + + messages = backtrace_symbols(array, size); + + +void sig_handler(int sig, siginfo_t* info, void* _ctx) { +ucontext_t *context = (ucontext_t*) _ctx; + +psiginfo(info, "Shit hit the fan"); +exit(EXIT_FAILURE); +} + +using namespace std; + +void badass() { +cout << "baddass!" << endl; +((char*)&badass)[0] = 42; +} + +int main() { +struct sigaction action; +action.sa_flags = SA_SIGINFO; +sigemptyset(&action.sa_mask); +action.sa_sigaction = &sig_handler; +int r = sigaction(SIGSEGV, &action, 0); +if (r < 0) { err(errno, 0); } +r = sigaction(SIGILL, &action, 0); +if (r < 0) { err(errno, 0); } + +badass(); +return 0; +} + + +#endif + +// i want to get a stacktrace on: +// - abort +// - signals (segfault.. abort...) +// - exception +// - dont messup with gdb! +// - thread ID +// - helper for capturing stack trace inside exception +// propose a little magic wrapper to throw an exception adding a stacktrace, +// and propose a specific tool to get a stacktrace from an exception (if its +// available). +// - optional override __cxa_throw, then the specific magic tool could get +// the stacktrace. Might be possible to use a thread-local variable to do +// some shit. RTLD_DEEPBIND might do the tricks to override it on the fly. + +// maybe I can even get the last variables and theirs values? +// that might be possible. + +// print with code snippet +// print traceback demangled +// detect color stuff +// register all signals +// +// Seperate stacktrace (load and co function) +// than object extracting informations about a stack trace. + +// also public a simple function to print a stacktrace. + +// backtrace::StackTrace st; +// st.snapshot(); +// print(st); +// cout << st; + +} // namespace backward + +#endif /* H_GUARD */