--- /dev/null
+/*
+ * backward.hpp
+ * Copyright 2013 Google Inc. All Rights Reserved.
+ *
+ * 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 || (defined(_MSC_VER) && _MSC_VER >= 1800)
+#define BACKWARD_CXX11
+#define BACKWARD_ATLEAST_CXX11
+#define BACKWARD_ATLEAST_CXX98
+#if __cplusplus >= 201703L || (defined(_MSVC_LANG) && _MSVC_LANG >= 201703L)
+#define BACKWARD_ATLEAST_CXX17
+#endif
+#else
+#define BACKWARD_CXX98
+#define BACKWARD_ATLEAST_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_DARWIN
+// - specialization for Mac OS X 10.5 and later.
+//
+// #define BACKWARD_SYSTEM_WINDOWS
+// - specialization for Windows (Clang 9 and MSVC2017)
+//
+// #define BACKWARD_SYSTEM_UNKNOWN
+// - placebo implementation, does nothing.
+//
+#if defined(BACKWARD_SYSTEM_LINUX)
+#elif defined(BACKWARD_SYSTEM_DARWIN)
+#elif defined(BACKWARD_SYSTEM_UNKNOWN)
+#elif defined(BACKWARD_SYSTEM_WINDOWS)
+#else
+#if defined(__linux) || defined(__linux__)
+#define BACKWARD_SYSTEM_LINUX
+#elif defined(__APPLE__)
+#define BACKWARD_SYSTEM_DARWIN
+#elif defined(_WIN32)
+#define BACKWARD_SYSTEM_WINDOWS
+#else
+#define BACKWARD_SYSTEM_UNKNOWN
+#endif
+#endif
+
+#define NOINLINE __attribute__((noinline))
+
+#include <algorithm>
+#include <cctype>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <fstream>
+#include <iomanip>
+#include <iostream>
+#include <limits>
+#include <new>
+#include <sstream>
+#include <streambuf>
+#include <string>
+#include <vector>
+#include <exception>
+#include <iterator>
+
+#if defined(BACKWARD_SYSTEM_LINUX)
+
+// On linux, backtrace can back-trace or "walk" the stack using the following
+// libraries:
+//
+// #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_LIBUNWIND 1
+// - libunwind provides, in some cases, a more accurate stacktrace as it knows
+// to decode signal handler frames and lets us edit the context registers when
+// unwinding, allowing stack traces over bad function references.
+//
+// #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
+//
+// Note that only one of the define should be set to 1 at a time.
+//
+#if BACKWARD_HAS_UNWIND == 1
+#elif BACKWARD_HAS_LIBUNWIND == 1
+#elif BACKWARD_HAS_BACKTRACE == 1
+#else
+#undef BACKWARD_HAS_UNWIND
+#define BACKWARD_HAS_UNWIND 1
+#undef BACKWARD_HAS_LIBUNWIND
+#define BACKWARD_HAS_LIBUNWIND 0
+#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 libraries:
+//
+// #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)
+// - variable names (if not optimized out)
+// - variable values (not supported by backward-cpp)
+// - 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 amount 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_DWARF 1
+// - libdwarf 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)
+// - variable names (if not optimized out)
+// - variable values (not supported by backward-cpp)
+// - You need to link with the lib "dwarf":
+// - apt-get install libdwarf-dev
+// - g++/clang++ -ldwarf ...
+//
+// #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
+//
+// Note that only one of the define should be set to 1 at a time.
+//
+#if BACKWARD_HAS_DW == 1
+#elif BACKWARD_HAS_BFD == 1
+#elif BACKWARD_HAS_DWARF == 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_DWARF
+#define BACKWARD_HAS_DWARF 0
+#undef BACKWARD_HAS_BACKTRACE_SYMBOL
+#define BACKWARD_HAS_BACKTRACE_SYMBOL 1
+#endif
+
+#include <cxxabi.h>
+#include <fcntl.h>
+#ifdef __ANDROID__
+// Old Android API levels define _Unwind_Ptr in both link.h and
+// unwind.h Rename the one in link.h as we are not going to be using
+// it
+#define _Unwind_Ptr _Unwind_Ptr_Custom
+#include <link.h>
+#undef _Unwind_Ptr
+#else
+#include <link.h>
+#endif
+#include <signal.h>
+#include <sys/stat.h>
+#include <syscall.h>
+#include <unistd.h>
+
+#if BACKWARD_HAS_BFD == 1
+// NOTE: defining PACKAGE{,_VERSION} is required before including
+// bfd.h on some platforms, see also:
+// https://sourceware.org/bugzilla/show_bug.cgi?id=14243
+#ifndef PACKAGE
+#define PACKAGE
+#endif
+#ifndef PACKAGE_VERSION
+#define PACKAGE_VERSION
+#endif
+#include <bfd.h>
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#include <dlfcn.h>
+#undef _GNU_SOURCE
+#else
+#include <dlfcn.h>
+#endif
+#endif
+
+#if BACKWARD_HAS_DW == 1
+#include <dwarf.h>
+#include <elfutils/libdw.h>
+#include <elfutils/libdwfl.h>
+#endif
+
+#if BACKWARD_HAS_DWARF == 1
+#include <algorithm>
+#include <dwarf.h>
+#include <libdwarf.h>
+#include <libelf.h>
+#include <map>
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#include <dlfcn.h>
+#undef _GNU_SOURCE
+#else
+#include <dlfcn.h>
+#endif
+#endif
+
+#if (BACKWARD_HAS_BACKTRACE == 1) || (BACKWARD_HAS_BACKTRACE_SYMBOL == 1)
+// then we shall rely on backtrace
+#include <execinfo.h>
+#endif
+
+#endif // defined(BACKWARD_SYSTEM_LINUX)
+
+#if defined(BACKWARD_SYSTEM_DARWIN)
+// On Darwin, backtrace can back-trace or "walk" the stack using the following
+// libraries:
+//
+// #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_LIBUNWIND 1
+// - libunwind comes from clang, which implements an API compatible version.
+// - libunwind provides, in some cases, a more accurate stacktrace as it knows
+// to decode signal handler frames and lets us edit the context registers when
+// unwinding, allowing stack traces over bad function references.
+//
+// #define BACKWARD_HAS_BACKTRACE == 1
+// - backtrace is available by default, though it does not produce as much
+// information as another library might.
+//
+// The default is:
+// #define BACKWARD_HAS_UNWIND == 1
+//
+// Note that only one of the define should be set to 1 at a time.
+//
+#if BACKWARD_HAS_UNWIND == 1
+#elif BACKWARD_HAS_BACKTRACE == 1
+#elif BACKWARD_HAS_LIBUNWIND == 1
+#else
+#undef BACKWARD_HAS_UNWIND
+#define BACKWARD_HAS_UNWIND 1
+#undef BACKWARD_HAS_BACKTRACE
+#define BACKWARD_HAS_BACKTRACE 0
+#undef BACKWARD_HAS_LIBUNWIND
+#define BACKWARD_HAS_LIBUNWIND 0
+#endif
+
+// On Darwin, backward can extract detailed information about a stack trace
+// using one of the following libraries:
+//
+// #define BACKWARD_HAS_BACKTRACE_SYMBOL 1
+// - backtrace provides minimal details for a stack trace:
+// - object filename
+// - function name
+//
+// The default is:
+// #define BACKWARD_HAS_BACKTRACE_SYMBOL == 1
+//
+#if BACKWARD_HAS_BACKTRACE_SYMBOL == 1
+#else
+#undef BACKWARD_HAS_BACKTRACE_SYMBOL
+#define BACKWARD_HAS_BACKTRACE_SYMBOL 1
+#endif
+
+#include <cxxabi.h>
+#include <fcntl.h>
+#include <pthread.h>
+#include <signal.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#if (BACKWARD_HAS_BACKTRACE == 1) || (BACKWARD_HAS_BACKTRACE_SYMBOL == 1)
+#include <execinfo.h>
+#endif
+#endif // defined(BACKWARD_SYSTEM_DARWIN)
+
+#if defined(BACKWARD_SYSTEM_WINDOWS)
+
+#include <condition_variable>
+#include <mutex>
+#include <thread>
+
+#include <basetsd.h>
+typedef SSIZE_T ssize_t;
+
+#ifndef NOMINMAX
+#define NOMINMAX
+#endif
+#include <windows.h>
+#include <winnt.h>
+
+#include <psapi.h>
+#include <signal.h>
+
+#ifndef __clang__
+#undef NOINLINE
+#define NOINLINE __declspec(noinline)
+#endif
+
+#ifdef _MSC_VER
+#pragma comment(lib, "psapi.lib")
+#pragma comment(lib, "dbghelp.lib")
+#endif
+
+// Comment / packing is from stackoverflow:
+// https://stackoverflow.com/questions/6205981/windows-c-stack-trace-from-a-running-app/28276227#28276227
+// Some versions of imagehlp.dll lack the proper packing directives themselves
+// so we need to do it.
+#pragma pack(push, before_imagehlp, 8)
+#include <imagehlp.h>
+#pragma pack(pop, before_imagehlp)
+
+// TODO maybe these should be undefined somewhere else?
+#undef BACKWARD_HAS_UNWIND
+#undef BACKWARD_HAS_BACKTRACE
+#if BACKWARD_HAS_PDB_SYMBOL == 1
+#else
+#undef BACKWARD_HAS_PDB_SYMBOL
+#define BACKWARD_HAS_PDB_SYMBOL 1
+#endif
+
+#endif
+
+#if BACKWARD_HAS_UNWIND == 1
+
+#include <unwind.h>
+// while gcc's unwind.h defines something like that:
+// extern _Unwind_Ptr _Unwind_GetIP (struct _Unwind_Context *);
+// extern _Unwind_Ptr _Unwind_GetIPInfo (struct _Unwind_Context *, int *);
+//
+// clang's unwind.h defines something like this:
+// uintptr_t _Unwind_GetIP(struct _Unwind_Context* __context);
+//
+// Even if the _Unwind_GetIPInfo can be linked to, it is not declared, worse we
+// cannot just redeclare it because clang's unwind.h doesn't define _Unwind_Ptr
+// anyway.
+//
+// Luckily we can play on the fact that the guard macros have a different name:
+#ifdef __CLANG_UNWIND_H
+// In fact, this function still comes from libgcc (on my different linux boxes,
+// clang links against libgcc).
+#include <inttypes.h>
+extern "C" uintptr_t _Unwind_GetIPInfo(_Unwind_Context *, int *);
+#endif
+
+#endif // BACKWARD_HAS_UNWIND == 1
+
+#if BACKWARD_HAS_LIBUNWIND == 1
+#define UNW_LOCAL_ONLY
+#include <libunwind.h>
+#endif // BACKWARD_HAS_LIBUNWIND == 1
+
+#ifdef BACKWARD_ATLEAST_CXX11
+#include <unordered_map>
+#include <utility> // for std::swap
+namespace backward {
+namespace details {
+template <typename K, typename V> struct hashtable {
+ typedef std::unordered_map<K, V> type;
+};
+using std::move;
+} // namespace details
+} // namespace backward
+#else // NOT BACKWARD_ATLEAST_CXX11
+#define nullptr NULL
+#define override
+#include <map>
+namespace backward {
+namespace details {
+template <typename K, typename V> struct hashtable {
+ typedef std::map<K, V> type;
+};
+template <typename T> const T &move(const T &v) { return v; }
+template <typename T> T &move(T &v) { return v; }
+} // namespace details
+} // namespace backward
+#endif // BACKWARD_ATLEAST_CXX11
+
+namespace backward {
+namespace details {
+#if defined(BACKWARD_SYSTEM_WINDOWS)
+const char kBackwardPathDelimiter[] = ";";
+#else
+const char kBackwardPathDelimiter[] = ":";
+#endif
+} // namespace details
+} // namespace backward
+
+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 darwin_tag;
+struct windows_tag;
+struct unknown_tag;
+
+#if defined(BACKWARD_SYSTEM_LINUX)
+typedef linux_tag current_tag;
+#elif defined(BACKWARD_SYSTEM_DARWIN)
+typedef darwin_tag current_tag;
+#elif defined(BACKWARD_SYSTEM_WINDOWS)
+typedef windows_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 trace_resolver_tag {
+#if defined(BACKWARD_SYSTEM_LINUX)
+struct libdw;
+struct libbfd;
+struct libdwarf;
+struct backtrace_symbol;
+
+#if BACKWARD_HAS_DW == 1
+typedef libdw current;
+#elif BACKWARD_HAS_BFD == 1
+typedef libbfd current;
+#elif BACKWARD_HAS_DWARF == 1
+typedef libdwarf current;
+#elif BACKWARD_HAS_BACKTRACE_SYMBOL == 1
+typedef backtrace_symbol current;
+#else
+#error "You shall not pass, until you know what you want."
+#endif
+#elif defined(BACKWARD_SYSTEM_DARWIN)
+struct backtrace_symbol;
+
+#if BACKWARD_HAS_BACKTRACE_SYMBOL == 1
+typedef backtrace_symbol current;
+#else
+#error "You shall not pass, until you know what you want."
+#endif
+#elif defined(BACKWARD_SYSTEM_WINDOWS)
+struct pdb_symbol;
+#if BACKWARD_HAS_PDB_SYMBOL == 1
+typedef pdb_symbol current;
+#else
+#error "You shall not pass, until you know what you want."
+#endif
+#endif
+} // namespace trace_resolver_tag
+
+namespace details {
+
+template <typename T> struct rm_ptr { typedef T type; };
+
+template <typename T> struct rm_ptr<T *> { typedef T type; };
+
+template <typename T> struct rm_ptr<const T *> { typedef const T type; };
+
+template <typename R, typename T, R (*F)(T)> struct deleter {
+ template <typename U> void operator()(U &ptr) const { (*F)(ptr); }
+};
+
+template <typename T> struct default_delete {
+ void operator()(T &ptr) const { delete ptr; }
+};
+
+template <typename T, typename Deleter = deleter<void, void *, &::free>>
+class handle {
+ struct dummy;
+ T _val;
+ bool _empty;
+
+#ifdef BACKWARD_ATLEAST_CXX11
+ handle(const handle &) = delete;
+ handle &operator=(const handle &) = delete;
+#endif
+
+public:
+ ~handle() {
+ if (!_empty) {
+ Deleter()(_val);
+ }
+ }
+
+ explicit handle() : _val(), _empty(true) {}
+ explicit handle(T val) : _val(val), _empty(false) {
+ if (!_val)
+ _empty = true;
+ }
+
+#ifdef BACKWARD_ATLEAST_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<handle &>(from));
+ }
+ handle &operator=(const handle &from) {
+ // some sort of poor man's move semantic.
+ swap(const_cast<handle &>(from));
+ return *this;
+ }
+#endif
+
+ void reset(T new_val) {
+ handle tmp(new_val);
+ swap(tmp);
+ }
+
+ void update(T new_val) {
+ _val = new_val;
+ _empty = !static_cast<bool>(new_val);
+ }
+
+ operator const dummy *() const {
+ if (_empty) {
+ return nullptr;
+ }
+ return reinterpret_cast<const dummy *>(_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<T>::type &ref_t;
+ typedef const typename rm_ptr<T>::type &const_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;
+ }
+};
+
+// Default demangler implementation (do nothing).
+template <typename TAG> struct demangler_impl {
+ static std::string demangle(const char *funcname) { return funcname; }
+};
+
+#if defined(BACKWARD_SYSTEM_LINUX) || defined(BACKWARD_SYSTEM_DARWIN)
+
+template <> struct demangler_impl<system_tag::current_tag> {
+ demangler_impl() : _demangle_buffer_length(0) {}
+
+ std::string demangle(const char *funcname) {
+ using namespace details;
+ char *result = abi::__cxa_demangle(funcname, _demangle_buffer.get(),
+ &_demangle_buffer_length, nullptr);
+ if (result) {
+ _demangle_buffer.update(result);
+ return result;
+ }
+ return funcname;
+ }
+
+private:
+ details::handle<char *> _demangle_buffer;
+ size_t _demangle_buffer_length;
+};
+
+#endif // BACKWARD_SYSTEM_LINUX || BACKWARD_SYSTEM_DARWIN
+
+struct demangler : public demangler_impl<system_tag::current_tag> {};
+
+// Split a string on the platform's PATH delimiter. Example: if delimiter
+// is ":" then:
+// "" --> []
+// ":" --> ["",""]
+// "::" --> ["","",""]
+// "/a/b/c" --> ["/a/b/c"]
+// "/a/b/c:/d/e/f" --> ["/a/b/c","/d/e/f"]
+// etc.
+inline std::vector<std::string> split_source_prefixes(const std::string &s) {
+ std::vector<std::string> out;
+ size_t last = 0;
+ size_t next = 0;
+ size_t delimiter_size = sizeof(kBackwardPathDelimiter) - 1;
+ while ((next = s.find(kBackwardPathDelimiter, last)) != std::string::npos) {
+ out.push_back(s.substr(last, next - last));
+ last = next + delimiter_size;
+ }
+ if (last <= s.length()) {
+ out.push_back(s.substr(last));
+ }
+ return out;
+}
+
+} // namespace details
+
+/*************** A TRACE ***************/
+
+struct Trace {
+ void *addr;
+ size_t idx;
+
+ Trace() : addr(nullptr), idx(0) {}
+
+ explicit Trace(void *_addr, size_t _idx) : addr(_addr), idx(_idx) {}
+};
+
+struct ResolvedTrace : public Trace {
+
+ struct SourceLoc {
+ std::string function;
+ std::string filename;
+ unsigned line;
+ unsigned col;
+
+ SourceLoc() : line(0), col(0) {}
+
+ bool operator==(const SourceLoc &b) const {
+ return function == b.function && filename == b.filename &&
+ line == b.line && col == b.col;
+ }
+
+ bool operator!=(const SourceLoc &b) const { return !(*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<SourceLoc> source_locs_t;
+ source_locs_t inliners;
+
+ ResolvedTrace() : Trace() {}
+ ResolvedTrace(const Trace &mini_trace) : Trace(mini_trace) {}
+};
+
+/*************** STACK TRACE ***************/
+
+// default implemention.
+template <typename TAG> class StackTraceImpl {
+public:
+ size_t size() const { return 0; }
+ Trace operator[](size_t) const { return Trace(); }
+ size_t load_here(size_t = 0) { return 0; }
+ size_t load_from(void *, size_t = 0, void * = nullptr, void * = nullptr) {
+ return 0;
+ }
+ size_t thread_id() const { return 0; }
+ void skip_n_firsts(size_t) {}
+};
+
+class StackTraceImplBase {
+public:
+ StackTraceImplBase()
+ : _thread_id(0), _skip(0), _context(nullptr), _error_addr(nullptr) {}
+
+ size_t thread_id() const { return _thread_id; }
+
+ void skip_n_firsts(size_t n) { _skip = n; }
+
+protected:
+ void load_thread_info() {
+#ifdef BACKWARD_SYSTEM_LINUX
+#ifndef __ANDROID__
+ _thread_id = static_cast<size_t>(syscall(SYS_gettid));
+#else
+ _thread_id = static_cast<size_t>(gettid());
+#endif
+ if (_thread_id == static_cast<size_t>(getpid())) {
+ // If the thread is the main one, let's hide that.
+ // I like to keep little secret sometimes.
+ _thread_id = 0;
+ }
+#elif defined(BACKWARD_SYSTEM_DARWIN)
+ _thread_id = reinterpret_cast<size_t>(pthread_self());
+ if (pthread_main_np() == 1) {
+ // If the thread is the main one, let's hide that.
+ _thread_id = 0;
+ }
+#endif
+ }
+
+ void set_context(void *context) { _context = context; }
+ void *context() const { return _context; }
+
+ void set_error_addr(void *error_addr) { _error_addr = error_addr; }
+ void *error_addr() const { return _error_addr; }
+
+ size_t skip_n_firsts() const { return _skip; }
+
+private:
+ size_t _thread_id;
+ size_t _skip;
+ void *_context;
+ void *_error_addr;
+};
+
+class StackTraceImplHolder : public StackTraceImplBase {
+public:
+ size_t size() const {
+ return (_stacktrace.size() >= skip_n_firsts())
+ ? _stacktrace.size() - skip_n_firsts()
+ : 0;
+ }
+ Trace operator[](size_t idx) const {
+ if (idx >= size()) {
+ return Trace();
+ }
+ return Trace(_stacktrace[idx + skip_n_firsts()], idx);
+ }
+ void *const *begin() const {
+ if (size()) {
+ return &_stacktrace[skip_n_firsts()];
+ }
+ return nullptr;
+ }
+
+protected:
+ std::vector<void *> _stacktrace;
+};
+
+#if BACKWARD_HAS_UNWIND == 1
+
+namespace details {
+
+template <typename F> class Unwinder {
+public:
+ size_t operator()(F &f, size_t depth) {
+ _f = &f;
+ _index = -1;
+ _depth = depth;
+ _Unwind_Backtrace(&this->backtrace_trampoline, this);
+ return static_cast<size_t>(_index);
+ }
+
+private:
+ F *_f;
+ ssize_t _index;
+ size_t _depth;
+
+ static _Unwind_Reason_Code backtrace_trampoline(_Unwind_Context *ctx,
+ void *self) {
+ return (static_cast<Unwinder *>(self))->backtrace(ctx);
+ }
+
+ _Unwind_Reason_Code backtrace(_Unwind_Context *ctx) {
+ if (_index >= 0 && static_cast<size_t>(_index) >= _depth)
+ return _URC_END_OF_STACK;
+
+ int ip_before_instruction = 0;
+ uintptr_t ip = _Unwind_GetIPInfo(ctx, &ip_before_instruction);
+
+ if (!ip_before_instruction) {
+ // calculating 0-1 for unsigned, looks like a possible bug to sanitiziers,
+ // so let's do it explicitly:
+ if (ip == 0) {
+ ip = std::numeric_limits<uintptr_t>::max(); // set it to 0xffff... (as
+ // from casting 0-1)
+ } else {
+ ip -= 1; // else just normally decrement it (no overflow/underflow will
+ // happen)
+ }
+ }
+
+ if (_index >= 0) { // ignore first frame.
+ (*_f)(static_cast<size_t>(_index), reinterpret_cast<void *>(ip));
+ }
+ _index += 1;
+ return _URC_NO_REASON;
+ }
+};
+
+template <typename F> size_t unwind(F f, size_t depth) {
+ Unwinder<F> unwinder;
+ return unwinder(f, depth);
+}
+
+} // namespace details
+
+template <>
+class StackTraceImpl<system_tag::current_tag> : public StackTraceImplHolder {
+public:
+ NOINLINE
+ size_t load_here(size_t depth = 32, void *context = nullptr,
+ void *error_addr = nullptr) {
+ load_thread_info();
+ set_context(context);
+ set_error_addr(error_addr);
+ 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, void *context = nullptr,
+ void *error_addr = nullptr) {
+ load_here(depth + 8, context, error_addr);
+
+ 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; }
+ };
+};
+
+#elif BACKWARD_HAS_LIBUNWIND == 1
+
+template <>
+class StackTraceImpl<system_tag::current_tag> : public StackTraceImplHolder {
+public:
+ __attribute__((noinline)) size_t load_here(size_t depth = 32,
+ void *_context = nullptr,
+ void *_error_addr = nullptr) {
+ set_context(_context);
+ set_error_addr(_error_addr);
+ load_thread_info();
+ if (depth == 0) {
+ return 0;
+ }
+ _stacktrace.resize(depth + 1);
+
+ int result = 0;
+
+ unw_context_t ctx;
+ size_t index = 0;
+
+ // Add the tail call. If the Instruction Pointer is the crash address it
+ // means we got a bad function pointer dereference, so we "unwind" the
+ // bad pointer manually by using the return address pointed to by the
+ // Stack Pointer as the Instruction Pointer and letting libunwind do
+ // the rest
+
+ if (context()) {
+ ucontext_t *uctx = reinterpret_cast<ucontext_t *>(context());
+#ifdef REG_RIP // x86_64
+ if (uctx->uc_mcontext.gregs[REG_RIP] ==
+ reinterpret_cast<greg_t>(error_addr())) {
+ uctx->uc_mcontext.gregs[REG_RIP] =
+ *reinterpret_cast<size_t *>(uctx->uc_mcontext.gregs[REG_RSP]);
+ }
+ _stacktrace[index] =
+ reinterpret_cast<void *>(uctx->uc_mcontext.gregs[REG_RIP]);
+ ++index;
+ ctx = *reinterpret_cast<unw_context_t *>(uctx);
+#elif defined(REG_EIP) // x86_32
+ if (uctx->uc_mcontext.gregs[REG_EIP] ==
+ reinterpret_cast<greg_t>(error_addr())) {
+ uctx->uc_mcontext.gregs[REG_EIP] =
+ *reinterpret_cast<size_t *>(uctx->uc_mcontext.gregs[REG_ESP]);
+ }
+ _stacktrace[index] =
+ reinterpret_cast<void *>(uctx->uc_mcontext.gregs[REG_EIP]);
+ ++index;
+ ctx = *reinterpret_cast<unw_context_t *>(uctx);
+#elif defined(__arm__)
+ // libunwind uses its own context type for ARM unwinding.
+ // Copy the registers from the signal handler's context so we can
+ // unwind
+ unw_getcontext(&ctx);
+ ctx.regs[UNW_ARM_R0] = uctx->uc_mcontext.arm_r0;
+ ctx.regs[UNW_ARM_R1] = uctx->uc_mcontext.arm_r1;
+ ctx.regs[UNW_ARM_R2] = uctx->uc_mcontext.arm_r2;
+ ctx.regs[UNW_ARM_R3] = uctx->uc_mcontext.arm_r3;
+ ctx.regs[UNW_ARM_R4] = uctx->uc_mcontext.arm_r4;
+ ctx.regs[UNW_ARM_R5] = uctx->uc_mcontext.arm_r5;
+ ctx.regs[UNW_ARM_R6] = uctx->uc_mcontext.arm_r6;
+ ctx.regs[UNW_ARM_R7] = uctx->uc_mcontext.arm_r7;
+ ctx.regs[UNW_ARM_R8] = uctx->uc_mcontext.arm_r8;
+ ctx.regs[UNW_ARM_R9] = uctx->uc_mcontext.arm_r9;
+ ctx.regs[UNW_ARM_R10] = uctx->uc_mcontext.arm_r10;
+ ctx.regs[UNW_ARM_R11] = uctx->uc_mcontext.arm_fp;
+ ctx.regs[UNW_ARM_R12] = uctx->uc_mcontext.arm_ip;
+ ctx.regs[UNW_ARM_R13] = uctx->uc_mcontext.arm_sp;
+ ctx.regs[UNW_ARM_R14] = uctx->uc_mcontext.arm_lr;
+ ctx.regs[UNW_ARM_R15] = uctx->uc_mcontext.arm_pc;
+
+ // If we have crashed in the PC use the LR instead, as this was
+ // a bad function dereference
+ if (reinterpret_cast<unsigned long>(error_addr()) ==
+ uctx->uc_mcontext.arm_pc) {
+ ctx.regs[UNW_ARM_R15] =
+ uctx->uc_mcontext.arm_lr - sizeof(unsigned long);
+ }
+ _stacktrace[index] = reinterpret_cast<void *>(ctx.regs[UNW_ARM_R15]);
+ ++index;
+#elif defined(__APPLE__) && defined(__x86_64__)
+ unw_getcontext(&ctx);
+ // OS X's implementation of libunwind uses its own context object
+ // so we need to convert the passed context to libunwind's format
+ // (information about the data layout taken from unw_getcontext.s
+ // in Apple's libunwind source
+ ctx.data[0] = uctx->uc_mcontext->__ss.__rax;
+ ctx.data[1] = uctx->uc_mcontext->__ss.__rbx;
+ ctx.data[2] = uctx->uc_mcontext->__ss.__rcx;
+ ctx.data[3] = uctx->uc_mcontext->__ss.__rdx;
+ ctx.data[4] = uctx->uc_mcontext->__ss.__rdi;
+ ctx.data[5] = uctx->uc_mcontext->__ss.__rsi;
+ ctx.data[6] = uctx->uc_mcontext->__ss.__rbp;
+ ctx.data[7] = uctx->uc_mcontext->__ss.__rsp;
+ ctx.data[8] = uctx->uc_mcontext->__ss.__r8;
+ ctx.data[9] = uctx->uc_mcontext->__ss.__r9;
+ ctx.data[10] = uctx->uc_mcontext->__ss.__r10;
+ ctx.data[11] = uctx->uc_mcontext->__ss.__r11;
+ ctx.data[12] = uctx->uc_mcontext->__ss.__r12;
+ ctx.data[13] = uctx->uc_mcontext->__ss.__r13;
+ ctx.data[14] = uctx->uc_mcontext->__ss.__r14;
+ ctx.data[15] = uctx->uc_mcontext->__ss.__r15;
+ ctx.data[16] = uctx->uc_mcontext->__ss.__rip;
+
+ // If the IP is the same as the crash address we have a bad function
+ // dereference The caller's address is pointed to by %rsp, so we
+ // dereference that value and set it to be the next frame's IP.
+ if (uctx->uc_mcontext->__ss.__rip ==
+ reinterpret_cast<__uint64_t>(error_addr())) {
+ ctx.data[16] =
+ *reinterpret_cast<__uint64_t *>(uctx->uc_mcontext->__ss.__rsp);
+ }
+ _stacktrace[index] = reinterpret_cast<void *>(ctx.data[16]);
+ ++index;
+#elif defined(__APPLE__)
+ unw_getcontext(&ctx)
+ // TODO: Convert the ucontext_t to libunwind's unw_context_t like
+ // we do in 64 bits
+ if (ctx.uc_mcontext->__ss.__eip ==
+ reinterpret_cast<greg_t>(error_addr())) {
+ ctx.uc_mcontext->__ss.__eip = ctx.uc_mcontext->__ss.__esp;
+ }
+ _stacktrace[index] =
+ reinterpret_cast<void *>(ctx.uc_mcontext->__ss.__eip);
+ ++index;
+#endif
+ }
+
+ unw_cursor_t cursor;
+ if (context()) {
+#if defined(UNW_INIT_SIGNAL_FRAME)
+ result = unw_init_local2(&cursor, &ctx, UNW_INIT_SIGNAL_FRAME);
+#else
+ result = unw_init_local(&cursor, &ctx);
+#endif
+ } else {
+ unw_getcontext(&ctx);
+ ;
+ result = unw_init_local(&cursor, &ctx);
+ }
+
+ if (result != 0)
+ return 1;
+
+ unw_word_t ip = 0;
+
+ while (index <= depth && unw_step(&cursor) > 0) {
+ result = unw_get_reg(&cursor, UNW_REG_IP, &ip);
+ if (result == 0) {
+ _stacktrace[index] = reinterpret_cast<void *>(--ip);
+ ++index;
+ }
+ }
+ --index;
+
+ _stacktrace.resize(index + 1);
+ skip_n_firsts(0);
+ return size();
+ }
+
+ size_t load_from(void *addr, size_t depth = 32, void *context = nullptr,
+ void *error_addr = nullptr) {
+ load_here(depth + 8, context, error_addr);
+
+ for (size_t i = 0; i < _stacktrace.size(); ++i) {
+ if (_stacktrace[i] == addr) {
+ skip_n_firsts(i);
+ _stacktrace[i] = (void *)((uintptr_t)_stacktrace[i]);
+ break;
+ }
+ }
+
+ _stacktrace.resize(std::min(_stacktrace.size(), skip_n_firsts() + depth));
+ return size();
+ }
+};
+
+#elif defined(BACKWARD_HAS_BACKTRACE)
+
+template <>
+class StackTraceImpl<system_tag::current_tag> : public StackTraceImplHolder {
+public:
+ NOINLINE
+ size_t load_here(size_t depth = 32, void *context = nullptr,
+ void *error_addr = nullptr) {
+ set_context(context);
+ set_error_addr(error_addr);
+ 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, void *context = nullptr,
+ void *error_addr = nullptr) {
+ load_here(depth + 8, context, error_addr);
+
+ 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();
+ }
+};
+
+#elif defined(BACKWARD_SYSTEM_WINDOWS)
+
+template <>
+class StackTraceImpl<system_tag::current_tag> : public StackTraceImplHolder {
+public:
+ // We have to load the machine type from the image info
+ // So we first initialize the resolver, and it tells us this info
+ void set_machine_type(DWORD machine_type) { machine_type_ = machine_type; }
+ void set_context(CONTEXT *ctx) { ctx_ = ctx; }
+ void set_thread_handle(HANDLE handle) { thd_ = handle; }
+
+ NOINLINE
+ size_t load_here(size_t depth = 32, void *context = nullptr,
+ void *error_addr = nullptr) {
+ set_context(static_cast<CONTEXT*>(context));
+ set_error_addr(error_addr);
+ CONTEXT localCtx; // used when no context is provided
+
+ if (depth == 0) {
+ return 0;
+ }
+
+ if (!ctx_) {
+ ctx_ = &localCtx;
+ RtlCaptureContext(ctx_);
+ }
+
+ if (!thd_) {
+ thd_ = GetCurrentThread();
+ }
+
+ HANDLE process = GetCurrentProcess();
+
+ STACKFRAME64 s;
+ memset(&s, 0, sizeof(STACKFRAME64));
+
+ // TODO: 32 bit context capture
+ s.AddrStack.Mode = AddrModeFlat;
+ s.AddrFrame.Mode = AddrModeFlat;
+ s.AddrPC.Mode = AddrModeFlat;
+#ifdef _M_X64
+ s.AddrPC.Offset = ctx_->Rip;
+ s.AddrStack.Offset = ctx_->Rsp;
+ s.AddrFrame.Offset = ctx_->Rbp;
+#else
+ s.AddrPC.Offset = ctx_->Eip;
+ s.AddrStack.Offset = ctx_->Esp;
+ s.AddrFrame.Offset = ctx_->Ebp;
+#endif
+
+ if (!machine_type_) {
+#ifdef _M_X64
+ machine_type_ = IMAGE_FILE_MACHINE_AMD64;
+#else
+ machine_type_ = IMAGE_FILE_MACHINE_I386;
+#endif
+ }
+
+ for (;;) {
+ // NOTE: this only works if PDBs are already loaded!
+ SetLastError(0);
+ if (!StackWalk64(machine_type_, process, thd_, &s, ctx_, NULL,
+ SymFunctionTableAccess64, SymGetModuleBase64, NULL))
+ break;
+
+ if (s.AddrReturn.Offset == 0)
+ break;
+
+ _stacktrace.push_back(reinterpret_cast<void *>(s.AddrPC.Offset));
+
+ if (size() >= depth)
+ break;
+ }
+
+ return size();
+ }
+
+ size_t load_from(void *addr, size_t depth = 32, void *context = nullptr,
+ void *error_addr = nullptr) {
+ load_here(depth + 8, context, error_addr);
+
+ 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:
+ DWORD machine_type_ = 0;
+ HANDLE thd_ = 0;
+ CONTEXT *ctx_ = nullptr;
+};
+
+#endif
+
+class StackTrace : public StackTraceImpl<system_tag::current_tag> {};
+
+/*************** TRACE RESOLVER ***************/
+
+class TraceResolverImplBase {
+public:
+ virtual ~TraceResolverImplBase() {}
+
+ virtual void load_addresses(void *const*addresses, int address_count) {
+ (void)addresses;
+ (void)address_count;
+ }
+
+ template <class ST> void load_stacktrace(ST &st) {
+ load_addresses(st.begin(), (int)st.size());
+ }
+
+ virtual ResolvedTrace resolve(ResolvedTrace t) { return t; }
+
+protected:
+ std::string demangle(const char *funcname) {
+ return _demangler.demangle(funcname);
+ }
+
+private:
+ details::demangler _demangler;
+};
+
+template <typename TAG> class TraceResolverImpl;
+
+#ifdef BACKWARD_SYSTEM_UNKNOWN
+
+template <> class TraceResolverImpl<system_tag::unknown_tag>
+ : public TraceResolverImplBase {};
+
+#endif
+
+#ifdef BACKWARD_SYSTEM_LINUX
+
+class TraceResolverLinuxBase : public TraceResolverImplBase {
+public:
+ TraceResolverLinuxBase()
+ : argv0_(get_argv0()), exec_path_(read_symlink("/proc/self/exe")) {}
+ std::string resolve_exec_path(Dl_info &symbol_info) const {
+ // mutates symbol_info.dli_fname to be filename to open and returns filename
+ // to display
+ if (symbol_info.dli_fname == argv0_) {
+ // dladdr returns argv[0] in dli_fname for symbols contained in
+ // the main executable, which is not a valid path if the
+ // executable was found by a search of the PATH environment
+ // variable; In that case, we actually open /proc/self/exe, which
+ // is always the actual executable (even if it was deleted/replaced!)
+ // but display the path that /proc/self/exe links to.
+ // However, this right away reduces probability of successful symbol
+ // resolution, because libbfd may try to find *.debug files in the
+ // same dir, in case symbols are stripped. As a result, it may try
+ // to find a file /proc/self/<exe_name>.debug, which obviously does
+ // not exist. /proc/self/exe is a last resort. First load attempt
+ // should go for the original executable file path.
+ symbol_info.dli_fname = "/proc/self/exe";
+ return exec_path_;
+ } else {
+ return symbol_info.dli_fname;
+ }
+ }
+
+private:
+ std::string argv0_;
+ std::string exec_path_;
+
+ static std::string get_argv0() {
+ std::string argv0;
+ std::ifstream ifs("/proc/self/cmdline");
+ std::getline(ifs, argv0, '\0');
+ return argv0;
+ }
+
+ static std::string read_symlink(std::string const &symlink_path) {
+ std::string path;
+ path.resize(100);
+
+ while (true) {
+ ssize_t len =
+ ::readlink(symlink_path.c_str(), &*path.begin(), path.size());
+ if (len < 0) {
+ return "";
+ }
+ if (static_cast<size_t>(len) == path.size()) {
+ path.resize(path.size() * 2);
+ } else {
+ path.resize(static_cast<std::string::size_type>(len));
+ break;
+ }
+ }
+
+ return path;
+ }
+};
+
+template <typename STACKTRACE_TAG> class TraceResolverLinuxImpl;
+
+#if BACKWARD_HAS_BACKTRACE_SYMBOL == 1
+
+template <>
+class TraceResolverLinuxImpl<trace_resolver_tag::backtrace_symbol>
+ : public TraceResolverLinuxBase {
+public:
+ void load_addresses(void *const*addresses, int address_count) override {
+ if (address_count == 0) {
+ return;
+ }
+ _symbols.reset(backtrace_symbols(addresses, address_count));
+ }
+
+ ResolvedTrace resolve(ResolvedTrace trace) override {
+ char *filename = _symbols[trace.idx];
+ char *funcname = filename;
+ while (*funcname && *funcname != '(') {
+ funcname += 1;
+ }
+ trace.object_filename.assign(filename,
+ funcname); // ok even if funcname is the ending
+ // \0 (then we assign entire string)
+
+ if (*funcname) { // if it's not end of string (e.g. from last frame ip==0)
+ funcname += 1;
+ 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<char **> _symbols;
+};
+
+#endif // BACKWARD_HAS_BACKTRACE_SYMBOL == 1
+
+#if BACKWARD_HAS_BFD == 1
+
+template <>
+class TraceResolverLinuxImpl<trace_resolver_tag::libbfd>
+ : public TraceResolverLinuxBase {
+public:
+ TraceResolverLinuxImpl() : _bfd_loaded(false) {}
+
+ ResolvedTrace resolve(ResolvedTrace trace) override {
+ 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 (!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 (!symbol_info.dli_fname) {
+ return trace;
+ }
+
+ trace.object_filename = resolve_exec_path(symbol_info);
+ bfd_fileobject *fobj;
+ // Before rushing to resolution need to ensure the executable
+ // file still can be used. For that compare inode numbers of
+ // what is stored by the executable's file path, and in the
+ // dli_fname, which not necessarily equals to the executable.
+ // It can be a shared library, or /proc/self/exe, and in the
+ // latter case has drawbacks. See the exec path resolution for
+ // details. In short - the dli object should be used only as
+ // the last resort.
+ // If inode numbers are equal, it is known dli_fname and the
+ // executable file are the same. This is guaranteed by Linux,
+ // because if the executable file is changed/deleted, it will
+ // be done in a new inode. The old file will be preserved in
+ // /proc/self/exe, and may even have inode 0. The latter can
+ // happen if the inode was actually reused, and the file was
+ // kept only in the main memory.
+ //
+ struct stat obj_stat;
+ struct stat dli_stat;
+ if (stat(trace.object_filename.c_str(), &obj_stat) == 0 &&
+ stat(symbol_info.dli_fname, &dli_stat) == 0 &&
+ obj_stat.st_ino == dli_stat.st_ino) {
+ // The executable file, and the shared object containing the
+ // address are the same file. Safe to use the original path.
+ // this is preferable. Libbfd will search for stripped debug
+ // symbols in the same directory.
+ fobj = load_object_with_bfd(trace.object_filename);
+ } else{
+ // The original object file was *deleted*! The only hope is
+ // that the debug symbols are either inside the shared
+ // object file, or are in the same directory, and this is
+ // not /proc/self/exe.
+ fobj = nullptr;
+ }
+ if (fobj == nullptr || !fobj->handle) {
+ fobj = load_object_with_bfd(symbol_info.dli_fname);
+ if (!fobj->handle) {
+ return trace;
+ }
+ }
+
+ 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 && 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 && 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 (!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 *,
+ details::deleter<bfd_boolean, bfd *, &bfd_close>>
+ bfd_handle_t;
+
+ typedef details::handle<asymbol **> bfd_symtab_t;
+
+ struct bfd_fileobject {
+ bfd_handle_t handle;
+ bfd_vma base_addr;
+ bfd_symtab_t symtab;
+ bfd_symtab_t dynamic_symtab;
+ };
+
+ typedef details::hashtable<std::string, bfd_fileobject>::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 (!_bfd_loaded) {
+ using namespace details;
+ bfd_init();
+ _bfd_loaded = true;
+ }
+
+ 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 (!bfd_handle) {
+ close(fd);
+ return r;
+ }
+
+ if (!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 && 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(static_cast<bfd_symbol **>(
+ malloc(static_cast<size_t>(symtab_storage_size))));
+ symcount = bfd_canonicalize_symtab(bfd_handle.get(), symtab.get());
+ }
+
+ if (dyn_symtab_storage_size > 0) {
+ dynamic_symtab.reset(static_cast<bfd_symbol **>(
+ malloc(static_cast<size_t>(dyn_symtab_storage_size))));
+ dyn_symcount = bfd_canonicalize_dynamic_symtab(bfd_handle.get(),
+ dynamic_symtab.get());
+ }
+
+ if (symcount <= 0 && 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,
+ static_cast<void *>(&context));
+ return context.result;
+ }
+
+ static void find_in_section_trampoline(bfd *, asection *section, void *data) {
+ find_sym_context *context = static_cast<find_sym_context *>(data);
+ context->self->find_in_section(
+ reinterpret_cast<bfd_vma>(context->addr),
+ reinterpret_cast<bfd_vma>(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;
+
+#ifdef bfd_get_section_flags
+ if ((bfd_get_section_flags(fobj->handle.get(), section) & SEC_ALLOC) == 0)
+#else
+ if ((bfd_section_flags(section) & SEC_ALLOC) == 0)
+#endif
+ return; // a debug section is never loaded automatically.
+
+#ifdef bfd_get_section_vma
+ bfd_vma sec_addr = bfd_get_section_vma(fobj->handle.get(), section);
+#else
+ bfd_vma sec_addr = bfd_section_vma(section);
+#endif
+#ifdef bfd_get_section_size
+ bfd_size_type size = bfd_get_section_size(section);
+#else
+ bfd_size_type size = bfd_section_size(section);
+#endif
+
+ // are we in the boundaries of the section?
+ if (addr < sec_addr || addr >= sec_addr + size) {
+ addr -= base_addr; // oups, a relocated object, lets try again...
+ if (addr < sec_addr || addr >= sec_addr + size) {
+ return;
+ }
+ }
+
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wzero-as-null-pointer-constant"
+#endif
+ if (!result.found && 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 (!result.found && 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);
+ }
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif
+ }
+
+ 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 (!a || !b) {
+ return false;
+ }
+ return strcmp(a, b) == 0;
+ }
+};
+#endif // BACKWARD_HAS_BFD == 1
+
+#if BACKWARD_HAS_DW == 1
+
+template <>
+class TraceResolverLinuxImpl<trace_resolver_tag::libdw>
+ : public TraceResolverLinuxBase {
+public:
+ TraceResolverLinuxImpl() : _dwfl_handle_initialized(false) {}
+
+ ResolvedTrace resolve(ResolvedTrace trace) override {
+ using namespace details;
+
+ Dwarf_Addr trace_addr = (Dwarf_Addr)trace.addr;
+
+ if (!_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 (!_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 (!_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 (!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 (!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<Dwarf_Frame *> frame;
+ dwarf_cfi_addrframe(cfi_cache, trace_addr - cfi_bias, &frame);
+ if (frame) {
+ break;
+ }
+ }
+ }
+ }
+#endif
+
+ if (!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 *, details::deleter<void, Dwfl *, &dwfl_end>>
+ dwfl_handle_t;
+ details::handle<Dwfl_Callbacks *, details::default_delete<Dwfl_Callbacks *>>
+ _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)) {
+ const char *name;
+ case DW_TAG_subprogram:
+ if ((name = dwarf_diename(die))) {
+ trace.source.function = name;
+ }
+ break;
+
+ case DW_TAG_inlined_subroutine:
+ ResolvedTrace::SourceLoc sloc;
+ Dwarf_Attribute attr_mem;
+
+ if ((name = dwarf_diename(die))) {
+ sloc.function = name;
+ }
+ if ((name = die_call_file(die))) {
+ sloc.filename = name;
+ }
+
+ 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 = (unsigned)line;
+ sloc.col = (unsigned)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) && 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 && 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 && 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;
+ }
+ };
+ bool declaration = false;
+ Dwarf_Attribute attr_mem;
+ dwarf_formflag(dwarf_attr(die, DW_AT_declaration, &attr_mem),
+ &declaration);
+ if (!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 <typename CB>
+ 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 (!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 (!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_Word file_idx = 0;
+
+ dwarf_formudata(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 (!cudie) {
+ return 0;
+ }
+
+ Dwarf_Files *files = 0;
+ size_t nfiles;
+ dwarf_getsrcfiles(cudie, &files, &nfiles);
+ if (!files) {
+ return 0;
+ }
+
+ return dwarf_filesrc(files, file_idx, 0, 0);
+ }
+};
+#endif // BACKWARD_HAS_DW == 1
+
+#if BACKWARD_HAS_DWARF == 1
+
+template <>
+class TraceResolverLinuxImpl<trace_resolver_tag::libdwarf>
+ : public TraceResolverLinuxBase {
+public:
+ TraceResolverLinuxImpl() : _dwarf_loaded(false) {}
+
+ ResolvedTrace resolve(ResolvedTrace trace) override {
+ // 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.
+
+ Dl_info symbol_info;
+ int dladdr_result = 0;
+#if defined(__GLIBC__)
+ link_map *link_map;
+ // We request the link map so we can get information about offsets
+ dladdr_result =
+ dladdr1(trace.addr, &symbol_info, reinterpret_cast<void **>(&link_map),
+ RTLD_DL_LINKMAP);
+#else
+ // Android doesn't have dladdr1. Don't use the linker map.
+ dladdr_result = dladdr(trace.addr, &symbol_info);
+#endif
+ if (!dladdr_result) {
+ 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.
+ //
+ // And in link_map:
+ // .l_addr:
+ // difference between the address in the ELF file and the address
+ // in memory
+ // l_name:
+ // absolute pathname where the object was found
+
+ if (symbol_info.dli_sname) {
+ trace.object_function = demangle(symbol_info.dli_sname);
+ }
+
+ if (!symbol_info.dli_fname) {
+ return trace;
+ }
+
+ trace.object_filename = resolve_exec_path(symbol_info);
+ dwarf_fileobject &fobj = load_object_with_dwarf(symbol_info.dli_fname);
+ if (!fobj.dwarf_handle) {
+ return trace; // sad, we couldn't load the object :(
+ }
+
+#if defined(__GLIBC__)
+ // Convert the address to a module relative one by looking at
+ // the module's loading address in the link map
+ Dwarf_Addr address = reinterpret_cast<uintptr_t>(trace.addr) -
+ reinterpret_cast<uintptr_t>(link_map->l_addr);
+#else
+ Dwarf_Addr address = reinterpret_cast<uintptr_t>(trace.addr);
+#endif
+
+ if (trace.object_function.empty()) {
+ symbol_cache_t::iterator it = fobj.symbol_cache.lower_bound(address);
+
+ if (it != fobj.symbol_cache.end()) {
+ if (it->first != address) {
+ if (it != fobj.symbol_cache.begin()) {
+ --it;
+ }
+ }
+ trace.object_function = demangle(it->second.c_str());
+ }
+ }
+
+ // Get the Compilation Unit DIE for the address
+ Dwarf_Die die = find_die(fobj, address);
+
+ if (!die) {
+ return trace; // this time we lost the game :/
+ }
+
+ // libdwarf doesn't give us direct access to its objects, it always
+ // allocates a copy for the caller. We keep that copy alive in a cache
+ // and we deallocate it later when it's no longer required.
+ die_cache_entry &die_object = get_die_cache(fobj, die);
+ if (die_object.isEmpty())
+ return trace; // We have no line section for this DIE
+
+ die_linemap_t::iterator it = die_object.line_section.lower_bound(address);
+
+ if (it != die_object.line_section.end()) {
+ if (it->first != address) {
+ if (it == die_object.line_section.begin()) {
+ // If we are on the first item of the line section
+ // but the address does not match it means that
+ // the address is below the range of the DIE. Give up.
+ return trace;
+ } else {
+ --it;
+ }
+ }
+ } else {
+ return trace; // We didn't find the address.
+ }
+
+ // Get the Dwarf_Line that the address points to and call libdwarf
+ // to get source file, line and column info.
+ Dwarf_Line line = die_object.line_buffer[it->second];
+ Dwarf_Error error = DW_DLE_NE;
+
+ char *filename;
+ if (dwarf_linesrc(line, &filename, &error) == DW_DLV_OK) {
+ trace.source.filename = std::string(filename);
+ dwarf_dealloc(fobj.dwarf_handle.get(), filename, DW_DLA_STRING);
+ }
+
+ Dwarf_Unsigned number = 0;
+ if (dwarf_lineno(line, &number, &error) == DW_DLV_OK) {
+ trace.source.line = number;
+ } else {
+ trace.source.line = 0;
+ }
+
+ if (dwarf_lineoff_b(line, &number, &error) == DW_DLV_OK) {
+ trace.source.col = number;
+ } else {
+ trace.source.col = 0;
+ }
+
+ std::vector<std::string> namespace_stack;
+ deep_first_search_by_pc(fobj, die, address, namespace_stack,
+ inliners_search_cb(trace, fobj, die));
+
+ dwarf_dealloc(fobj.dwarf_handle.get(), die, DW_DLA_DIE);
+
+ return trace;
+ }
+
+public:
+ static int close_dwarf(Dwarf_Debug dwarf) {
+ return dwarf_finish(dwarf, NULL);
+ }
+
+private:
+ bool _dwarf_loaded;
+
+ typedef details::handle<int, details::deleter<int, int, &::close>>
+ dwarf_file_t;
+
+ typedef details::handle<Elf *, details::deleter<int, Elf *, &elf_end>>
+ dwarf_elf_t;
+
+ typedef details::handle<Dwarf_Debug,
+ details::deleter<int, Dwarf_Debug, &close_dwarf>>
+ dwarf_handle_t;
+
+ typedef std::map<Dwarf_Addr, int> die_linemap_t;
+
+ typedef std::map<Dwarf_Off, Dwarf_Off> die_specmap_t;
+
+ struct die_cache_entry {
+ die_specmap_t spec_section;
+ die_linemap_t line_section;
+ Dwarf_Line *line_buffer;
+ Dwarf_Signed line_count;
+ Dwarf_Line_Context line_context;
+
+ inline bool isEmpty() {
+ return line_buffer == NULL || line_count == 0 || line_context == NULL ||
+ line_section.empty();
+ }
+
+ die_cache_entry() : line_buffer(0), line_count(0), line_context(0) {}
+
+ ~die_cache_entry() {
+ if (line_context) {
+ dwarf_srclines_dealloc_b(line_context);
+ }
+ }
+ };
+
+ typedef std::map<Dwarf_Off, die_cache_entry> die_cache_t;
+
+ typedef std::map<uintptr_t, std::string> symbol_cache_t;
+
+ struct dwarf_fileobject {
+ dwarf_file_t file_handle;
+ dwarf_elf_t elf_handle;
+ dwarf_handle_t dwarf_handle;
+ symbol_cache_t symbol_cache;
+
+ // Die cache
+ die_cache_t die_cache;
+ die_cache_entry *current_cu;
+ };
+
+ typedef details::hashtable<std::string, dwarf_fileobject>::type
+ fobj_dwarf_map_t;
+ fobj_dwarf_map_t _fobj_dwarf_map;
+
+ static bool cstrings_eq(const char *a, const char *b) {
+ if (!a || !b) {
+ return false;
+ }
+ return strcmp(a, b) == 0;
+ }
+
+ dwarf_fileobject &load_object_with_dwarf(const std::string &filename_object) {
+
+ if (!_dwarf_loaded) {
+ // Set the ELF library operating version
+ // If that fails there's nothing we can do
+ _dwarf_loaded = elf_version(EV_CURRENT) != EV_NONE;
+ }
+
+ fobj_dwarf_map_t::iterator it = _fobj_dwarf_map.find(filename_object);
+ if (it != _fobj_dwarf_map.end()) {
+ return it->second;
+ }
+
+ // this new object is empty for now
+ dwarf_fileobject &r = _fobj_dwarf_map[filename_object];
+
+ dwarf_file_t file_handle;
+ file_handle.reset(open(filename_object.c_str(), O_RDONLY));
+ if (file_handle.get() < 0) {
+ return r;
+ }
+
+ // Try to get an ELF handle. We need to read the ELF sections
+ // because we want to see if there is a .gnu_debuglink section
+ // that points to a split debug file
+ dwarf_elf_t elf_handle;
+ elf_handle.reset(elf_begin(file_handle.get(), ELF_C_READ, NULL));
+ if (!elf_handle) {
+ return r;
+ }
+
+ const char *e_ident = elf_getident(elf_handle.get(), 0);
+ if (!e_ident) {
+ return r;
+ }
+
+ // Get the number of sections
+ // We use the new APIs as elf_getshnum is deprecated
+ size_t shdrnum = 0;
+ if (elf_getshdrnum(elf_handle.get(), &shdrnum) == -1) {
+ return r;
+ }
+
+ // Get the index to the string section
+ size_t shdrstrndx = 0;
+ if (elf_getshdrstrndx(elf_handle.get(), &shdrstrndx) == -1) {
+ return r;
+ }
+
+ std::string debuglink;
+ // Iterate through the ELF sections to try to get a gnu_debuglink
+ // note and also to cache the symbol table.
+ // We go the preprocessor way to avoid having to create templated
+ // classes or using gelf (which might throw a compiler error if 64 bit
+ // is not supported
+#define ELF_GET_DATA(ARCH) \
+ Elf_Scn *elf_section = 0; \
+ Elf_Data *elf_data = 0; \
+ Elf##ARCH##_Shdr *section_header = 0; \
+ Elf_Scn *symbol_section = 0; \
+ size_t symbol_count = 0; \
+ size_t symbol_strings = 0; \
+ Elf##ARCH##_Sym *symbol = 0; \
+ const char *section_name = 0; \
+ \
+ while ((elf_section = elf_nextscn(elf_handle.get(), elf_section)) != NULL) { \
+ section_header = elf##ARCH##_getshdr(elf_section); \
+ if (section_header == NULL) { \
+ return r; \
+ } \
+ \
+ if ((section_name = elf_strptr(elf_handle.get(), shdrstrndx, \
+ section_header->sh_name)) == NULL) { \
+ return r; \
+ } \
+ \
+ if (cstrings_eq(section_name, ".gnu_debuglink")) { \
+ elf_data = elf_getdata(elf_section, NULL); \
+ if (elf_data && elf_data->d_size > 0) { \
+ debuglink = \
+ std::string(reinterpret_cast<const char *>(elf_data->d_buf)); \
+ } \
+ } \
+ \
+ switch (section_header->sh_type) { \
+ case SHT_SYMTAB: \
+ symbol_section = elf_section; \
+ symbol_count = section_header->sh_size / section_header->sh_entsize; \
+ symbol_strings = section_header->sh_link; \
+ break; \
+ \
+ /* We use .dynsyms as a last resort, we prefer .symtab */ \
+ case SHT_DYNSYM: \
+ if (!symbol_section) { \
+ symbol_section = elf_section; \
+ symbol_count = section_header->sh_size / section_header->sh_entsize; \
+ symbol_strings = section_header->sh_link; \
+ } \
+ break; \
+ } \
+ } \
+ \
+ if (symbol_section && symbol_count && symbol_strings) { \
+ elf_data = elf_getdata(symbol_section, NULL); \
+ symbol = reinterpret_cast<Elf##ARCH##_Sym *>(elf_data->d_buf); \
+ for (size_t i = 0; i < symbol_count; ++i) { \
+ int type = ELF##ARCH##_ST_TYPE(symbol->st_info); \
+ if (type == STT_FUNC && symbol->st_value > 0) { \
+ r.symbol_cache[symbol->st_value] = std::string( \
+ elf_strptr(elf_handle.get(), symbol_strings, symbol->st_name)); \
+ } \
+ ++symbol; \
+ } \
+ }
+
+ if (e_ident[EI_CLASS] == ELFCLASS32) {
+ ELF_GET_DATA(32)
+ } else if (e_ident[EI_CLASS] == ELFCLASS64) {
+ // libelf might have been built without 64 bit support
+#if __LIBELF64
+ ELF_GET_DATA(64)
+#endif
+ }
+
+ if (!debuglink.empty()) {
+ // We have a debuglink section! Open an elf instance on that
+ // file instead. If we can't open the file, then return
+ // the elf handle we had already opened.
+ dwarf_file_t debuglink_file;
+ debuglink_file.reset(open(debuglink.c_str(), O_RDONLY));
+ if (debuglink_file.get() > 0) {
+ dwarf_elf_t debuglink_elf;
+ debuglink_elf.reset(elf_begin(debuglink_file.get(), ELF_C_READ, NULL));
+
+ // If we have a valid elf handle, return the new elf handle
+ // and file handle and discard the original ones
+ if (debuglink_elf) {
+ elf_handle = move(debuglink_elf);
+ file_handle = move(debuglink_file);
+ }
+ }
+ }
+
+ // Ok, we have a valid ELF handle, let's try to get debug symbols
+ Dwarf_Debug dwarf_debug;
+ Dwarf_Error error = DW_DLE_NE;
+ dwarf_handle_t dwarf_handle;
+
+ int dwarf_result = dwarf_elf_init(elf_handle.get(), DW_DLC_READ, NULL, NULL,
+ &dwarf_debug, &error);
+
+ // We don't do any special handling for DW_DLV_NO_ENTRY specially.
+ // If we get an error, or the file doesn't have debug information
+ // we just return.
+ if (dwarf_result != DW_DLV_OK) {
+ return r;
+ }
+
+ dwarf_handle.reset(dwarf_debug);
+
+ r.file_handle = move(file_handle);
+ r.elf_handle = move(elf_handle);
+ r.dwarf_handle = move(dwarf_handle);
+
+ return r;
+ }
+
+ die_cache_entry &get_die_cache(dwarf_fileobject &fobj, Dwarf_Die die) {
+ Dwarf_Error error = DW_DLE_NE;
+
+ // Get the die offset, we use it as the cache key
+ Dwarf_Off die_offset;
+ if (dwarf_dieoffset(die, &die_offset, &error) != DW_DLV_OK) {
+ die_offset = 0;
+ }
+
+ die_cache_t::iterator it = fobj.die_cache.find(die_offset);
+
+ if (it != fobj.die_cache.end()) {
+ fobj.current_cu = &it->second;
+ return it->second;
+ }
+
+ die_cache_entry &de = fobj.die_cache[die_offset];
+ fobj.current_cu = &de;
+
+ Dwarf_Addr line_addr;
+ Dwarf_Small table_count;
+
+ // The addresses in the line section are not fully sorted (they might
+ // be sorted by block of code belonging to the same file), which makes
+ // it necessary to do so before searching is possible.
+ //
+ // As libdwarf allocates a copy of everything, let's get the contents
+ // of the line section and keep it around. We also create a map of
+ // program counter to line table indices so we can search by address
+ // and get the line buffer index.
+ //
+ // To make things more difficult, the same address can span more than
+ // one line, so we need to keep the index pointing to the first line
+ // by using insert instead of the map's [ operator.
+
+ // Get the line context for the DIE
+ if (dwarf_srclines_b(die, 0, &table_count, &de.line_context, &error) ==
+ DW_DLV_OK) {
+ // Get the source lines for this line context, to be deallocated
+ // later
+ if (dwarf_srclines_from_linecontext(de.line_context, &de.line_buffer,
+ &de.line_count,
+ &error) == DW_DLV_OK) {
+
+ // Add all the addresses to our map
+ for (int i = 0; i < de.line_count; i++) {
+ if (dwarf_lineaddr(de.line_buffer[i], &line_addr, &error) !=
+ DW_DLV_OK) {
+ line_addr = 0;
+ }
+ de.line_section.insert(std::pair<Dwarf_Addr, int>(line_addr, i));
+ }
+ }
+ }
+
+ // For each CU, cache the function DIEs that contain the
+ // DW_AT_specification attribute. When building with -g3 the function
+ // DIEs are separated in declaration and specification, with the
+ // declaration containing only the name and parameters and the
+ // specification the low/high pc and other compiler attributes.
+ //
+ // We cache those specifications so we don't skip over the declarations,
+ // because they have no pc, and we can do namespace resolution for
+ // DWARF function names.
+ Dwarf_Debug dwarf = fobj.dwarf_handle.get();
+ Dwarf_Die current_die = 0;
+ if (dwarf_child(die, ¤t_die, &error) == DW_DLV_OK) {
+ for (;;) {
+ Dwarf_Die sibling_die = 0;
+
+ Dwarf_Half tag_value;
+ dwarf_tag(current_die, &tag_value, &error);
+
+ if (tag_value == DW_TAG_subprogram ||
+ tag_value == DW_TAG_inlined_subroutine) {
+
+ Dwarf_Bool has_attr = 0;
+ if (dwarf_hasattr(current_die, DW_AT_specification, &has_attr,
+ &error) == DW_DLV_OK) {
+ if (has_attr) {
+ Dwarf_Attribute attr_mem;
+ if (dwarf_attr(current_die, DW_AT_specification, &attr_mem,
+ &error) == DW_DLV_OK) {
+ Dwarf_Off spec_offset = 0;
+ if (dwarf_formref(attr_mem, &spec_offset, &error) ==
+ DW_DLV_OK) {
+ Dwarf_Off spec_die_offset;
+ if (dwarf_dieoffset(current_die, &spec_die_offset, &error) ==
+ DW_DLV_OK) {
+ de.spec_section[spec_offset] = spec_die_offset;
+ }
+ }
+ }
+ dwarf_dealloc(dwarf, attr_mem, DW_DLA_ATTR);
+ }
+ }
+ }
+
+ int result = dwarf_siblingof(dwarf, current_die, &sibling_die, &error);
+ if (result == DW_DLV_ERROR) {
+ break;
+ } else if (result == DW_DLV_NO_ENTRY) {
+ break;
+ }
+
+ if (current_die != die) {
+ dwarf_dealloc(dwarf, current_die, DW_DLA_DIE);
+ current_die = 0;
+ }
+
+ current_die = sibling_die;
+ }
+ }
+ return de;
+ }
+
+ static Dwarf_Die get_referenced_die(Dwarf_Debug dwarf, Dwarf_Die die,
+ Dwarf_Half attr, bool global) {
+ Dwarf_Error error = DW_DLE_NE;
+ Dwarf_Attribute attr_mem;
+
+ Dwarf_Die found_die = NULL;
+ if (dwarf_attr(die, attr, &attr_mem, &error) == DW_DLV_OK) {
+ Dwarf_Off offset;
+ int result = 0;
+ if (global) {
+ result = dwarf_global_formref(attr_mem, &offset, &error);
+ } else {
+ result = dwarf_formref(attr_mem, &offset, &error);
+ }
+
+ if (result == DW_DLV_OK) {
+ if (dwarf_offdie(dwarf, offset, &found_die, &error) != DW_DLV_OK) {
+ found_die = NULL;
+ }
+ }
+ dwarf_dealloc(dwarf, attr_mem, DW_DLA_ATTR);
+ }
+ return found_die;
+ }
+
+ static std::string get_referenced_die_name(Dwarf_Debug dwarf, Dwarf_Die die,
+ Dwarf_Half attr, bool global) {
+ Dwarf_Error error = DW_DLE_NE;
+ std::string value;
+
+ Dwarf_Die found_die = get_referenced_die(dwarf, die, attr, global);
+
+ if (found_die) {
+ char *name;
+ if (dwarf_diename(found_die, &name, &error) == DW_DLV_OK) {
+ if (name) {
+ value = std::string(name);
+ }
+ dwarf_dealloc(dwarf, name, DW_DLA_STRING);
+ }
+ dwarf_dealloc(dwarf, found_die, DW_DLA_DIE);
+ }
+
+ return value;
+ }
+
+ // Returns a spec DIE linked to the passed one. The caller should
+ // deallocate the DIE
+ static Dwarf_Die get_spec_die(dwarf_fileobject &fobj, Dwarf_Die die) {
+ Dwarf_Debug dwarf = fobj.dwarf_handle.get();
+ Dwarf_Error error = DW_DLE_NE;
+ Dwarf_Off die_offset;
+ if (fobj.current_cu &&
+ dwarf_die_CU_offset(die, &die_offset, &error) == DW_DLV_OK) {
+ die_specmap_t::iterator it =
+ fobj.current_cu->spec_section.find(die_offset);
+
+ // If we have a DIE that completes the current one, check if
+ // that one has the pc we are looking for
+ if (it != fobj.current_cu->spec_section.end()) {
+ Dwarf_Die spec_die = 0;
+ if (dwarf_offdie(dwarf, it->second, &spec_die, &error) == DW_DLV_OK) {
+ return spec_die;
+ }
+ }
+ }
+
+ // Maybe we have an abstract origin DIE with the function information?
+ return get_referenced_die(fobj.dwarf_handle.get(), die,
+ DW_AT_abstract_origin, true);
+ }
+
+ static bool die_has_pc(dwarf_fileobject &fobj, Dwarf_Die die, Dwarf_Addr pc) {
+ Dwarf_Addr low_pc = 0, high_pc = 0;
+ Dwarf_Half high_pc_form = 0;
+ Dwarf_Form_Class return_class;
+ Dwarf_Error error = DW_DLE_NE;
+ Dwarf_Debug dwarf = fobj.dwarf_handle.get();
+ bool has_lowpc = false;
+ bool has_highpc = false;
+ bool has_ranges = false;
+
+ if (dwarf_lowpc(die, &low_pc, &error) == DW_DLV_OK) {
+ // If we have a low_pc check if there is a high pc.
+ // If we don't have a high pc this might mean we have a base
+ // address for the ranges list or just an address.
+ has_lowpc = true;
+
+ if (dwarf_highpc_b(die, &high_pc, &high_pc_form, &return_class, &error) ==
+ DW_DLV_OK) {
+ // We do have a high pc. In DWARF 4+ this is an offset from the
+ // low pc, but in earlier versions it's an absolute address.
+
+ has_highpc = true;
+ // In DWARF 2/3 this would be a DW_FORM_CLASS_ADDRESS
+ if (return_class == DW_FORM_CLASS_CONSTANT) {
+ high_pc = low_pc + high_pc;
+ }
+
+ // We have low and high pc, check if our address
+ // is in that range
+ return pc >= low_pc && pc < high_pc;
+ }
+ } else {
+ // Reset the low_pc, in case dwarf_lowpc failing set it to some
+ // undefined value.
+ low_pc = 0;
+ }
+
+ // Check if DW_AT_ranges is present and search for the PC in the
+ // returned ranges list. We always add the low_pc, as it not set it will
+ // be 0, in case we had a DW_AT_low_pc and DW_AT_ranges pair
+ bool result = false;
+
+ Dwarf_Attribute attr;
+ if (dwarf_attr(die, DW_AT_ranges, &attr, &error) == DW_DLV_OK) {
+
+ Dwarf_Off offset;
+ if (dwarf_global_formref(attr, &offset, &error) == DW_DLV_OK) {
+ Dwarf_Ranges *ranges;
+ Dwarf_Signed ranges_count = 0;
+ Dwarf_Unsigned byte_count = 0;
+
+ if (dwarf_get_ranges_a(dwarf, offset, die, &ranges, &ranges_count,
+ &byte_count, &error) == DW_DLV_OK) {
+ has_ranges = ranges_count != 0;
+ for (int i = 0; i < ranges_count; i++) {
+ if (ranges[i].dwr_addr1 != 0 &&
+ pc >= ranges[i].dwr_addr1 + low_pc &&
+ pc < ranges[i].dwr_addr2 + low_pc) {
+ result = true;
+ break;
+ }
+ }
+ dwarf_ranges_dealloc(dwarf, ranges, ranges_count);
+ }
+ }
+ }
+
+ // Last attempt. We might have a single address set as low_pc.
+ if (!result && low_pc != 0 && pc == low_pc) {
+ result = true;
+ }
+
+ // If we don't have lowpc, highpc and ranges maybe this DIE is a
+ // declaration that relies on a DW_AT_specification DIE that happens
+ // later. Use the specification cache we filled when we loaded this CU.
+ if (!result && (!has_lowpc && !has_highpc && !has_ranges)) {
+ Dwarf_Die spec_die = get_spec_die(fobj, die);
+ if (spec_die) {
+ result = die_has_pc(fobj, spec_die, pc);
+ dwarf_dealloc(dwarf, spec_die, DW_DLA_DIE);
+ }
+ }
+
+ return result;
+ }
+
+ static void get_type(Dwarf_Debug dwarf, Dwarf_Die die, std::string &type) {
+ Dwarf_Error error = DW_DLE_NE;
+
+ Dwarf_Die child = 0;
+ if (dwarf_child(die, &child, &error) == DW_DLV_OK) {
+ get_type(dwarf, child, type);
+ }
+
+ if (child) {
+ type.insert(0, "::");
+ dwarf_dealloc(dwarf, child, DW_DLA_DIE);
+ }
+
+ char *name;
+ if (dwarf_diename(die, &name, &error) == DW_DLV_OK) {
+ type.insert(0, std::string(name));
+ dwarf_dealloc(dwarf, name, DW_DLA_STRING);
+ } else {
+ type.insert(0, "<unknown>");
+ }
+ }
+
+ static std::string get_type_by_signature(Dwarf_Debug dwarf, Dwarf_Die die) {
+ Dwarf_Error error = DW_DLE_NE;
+
+ Dwarf_Sig8 signature;
+ Dwarf_Bool has_attr = 0;
+ if (dwarf_hasattr(die, DW_AT_signature, &has_attr, &error) == DW_DLV_OK) {
+ if (has_attr) {
+ Dwarf_Attribute attr_mem;
+ if (dwarf_attr(die, DW_AT_signature, &attr_mem, &error) == DW_DLV_OK) {
+ if (dwarf_formsig8(attr_mem, &signature, &error) != DW_DLV_OK) {
+ return std::string("<no type signature>");
+ }
+ }
+ dwarf_dealloc(dwarf, attr_mem, DW_DLA_ATTR);
+ }
+ }
+
+ Dwarf_Unsigned next_cu_header;
+ Dwarf_Sig8 tu_signature;
+ std::string result;
+ bool found = false;
+
+ while (dwarf_next_cu_header_d(dwarf, 0, 0, 0, 0, 0, 0, 0, &tu_signature, 0,
+ &next_cu_header, 0, &error) == DW_DLV_OK) {
+
+ if (strncmp(signature.signature, tu_signature.signature, 8) == 0) {
+ Dwarf_Die type_cu_die = 0;
+ if (dwarf_siblingof_b(dwarf, 0, 0, &type_cu_die, &error) == DW_DLV_OK) {
+ Dwarf_Die child_die = 0;
+ if (dwarf_child(type_cu_die, &child_die, &error) == DW_DLV_OK) {
+ get_type(dwarf, child_die, result);
+ found = !result.empty();
+ dwarf_dealloc(dwarf, child_die, DW_DLA_DIE);
+ }
+ dwarf_dealloc(dwarf, type_cu_die, DW_DLA_DIE);
+ }
+ }
+ }
+
+ if (found) {
+ while (dwarf_next_cu_header_d(dwarf, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ &next_cu_header, 0, &error) == DW_DLV_OK) {
+ // Reset the cu header state. Unfortunately, libdwarf's
+ // next_cu_header API keeps its own iterator per Dwarf_Debug
+ // that can't be reset. We need to keep fetching elements until
+ // the end.
+ }
+ } else {
+ // If we couldn't resolve the type just print out the signature
+ std::ostringstream string_stream;
+ string_stream << "<0x" << std::hex << std::setfill('0');
+ for (int i = 0; i < 8; ++i) {
+ string_stream << std::setw(2) << std::hex
+ << (int)(unsigned char)(signature.signature[i]);
+ }
+ string_stream << ">";
+ result = string_stream.str();
+ }
+ return result;
+ }
+
+ struct type_context_t {
+ bool is_const;
+ bool is_typedef;
+ bool has_type;
+ bool has_name;
+ std::string text;
+
+ type_context_t()
+ : is_const(false), is_typedef(false), has_type(false), has_name(false) {
+ }
+ };
+
+ // Types are resolved from right to left: we get the variable name first
+ // and then all specifiers (like const or pointer) in a chain of DW_AT_type
+ // DIEs. Call this function recursively until we get a complete type
+ // string.
+ static void set_parameter_string(dwarf_fileobject &fobj, Dwarf_Die die,
+ type_context_t &context) {
+ char *name;
+ Dwarf_Error error = DW_DLE_NE;
+
+ // typedefs contain also the base type, so we skip it and only
+ // print the typedef name
+ if (!context.is_typedef) {
+ if (dwarf_diename(die, &name, &error) == DW_DLV_OK) {
+ if (!context.text.empty()) {
+ context.text.insert(0, " ");
+ }
+ context.text.insert(0, std::string(name));
+ dwarf_dealloc(fobj.dwarf_handle.get(), name, DW_DLA_STRING);
+ }
+ } else {
+ context.is_typedef = false;
+ context.has_type = true;
+ if (context.is_const) {
+ context.text.insert(0, "const ");
+ context.is_const = false;
+ }
+ }
+
+ bool next_type_is_const = false;
+ bool is_keyword = true;
+
+ Dwarf_Half tag = 0;
+ Dwarf_Bool has_attr = 0;
+ if (dwarf_tag(die, &tag, &error) == DW_DLV_OK) {
+ switch (tag) {
+ case DW_TAG_structure_type:
+ case DW_TAG_union_type:
+ case DW_TAG_class_type:
+ case DW_TAG_enumeration_type:
+ context.has_type = true;
+ if (dwarf_hasattr(die, DW_AT_signature, &has_attr, &error) ==
+ DW_DLV_OK) {
+ // If we have a signature it means the type is defined
+ // in .debug_types, so we need to load the DIE pointed
+ // at by the signature and resolve it
+ if (has_attr) {
+ std::string type =
+ get_type_by_signature(fobj.dwarf_handle.get(), die);
+ if (context.is_const)
+ type.insert(0, "const ");
+
+ if (!context.text.empty())
+ context.text.insert(0, " ");
+ context.text.insert(0, type);
+ }
+
+ // Treat enums like typedefs, and skip printing its
+ // base type
+ context.is_typedef = (tag == DW_TAG_enumeration_type);
+ }
+ break;
+ case DW_TAG_const_type:
+ next_type_is_const = true;
+ break;
+ case DW_TAG_pointer_type:
+ context.text.insert(0, "*");
+ break;
+ case DW_TAG_reference_type:
+ context.text.insert(0, "&");
+ break;
+ case DW_TAG_restrict_type:
+ context.text.insert(0, "restrict ");
+ break;
+ case DW_TAG_rvalue_reference_type:
+ context.text.insert(0, "&&");
+ break;
+ case DW_TAG_volatile_type:
+ context.text.insert(0, "volatile ");
+ break;
+ case DW_TAG_typedef:
+ // Propagate the const-ness to the next type
+ // as typedefs are linked to its base type
+ next_type_is_const = context.is_const;
+ context.is_typedef = true;
+ context.has_type = true;
+ break;
+ case DW_TAG_base_type:
+ context.has_type = true;
+ break;
+ case DW_TAG_formal_parameter:
+ context.has_name = true;
+ break;
+ default:
+ is_keyword = false;
+ break;
+ }
+ }
+
+ if (!is_keyword && context.is_const) {
+ context.text.insert(0, "const ");
+ }
+
+ context.is_const = next_type_is_const;
+
+ Dwarf_Die ref =
+ get_referenced_die(fobj.dwarf_handle.get(), die, DW_AT_type, true);
+ if (ref) {
+ set_parameter_string(fobj, ref, context);
+ dwarf_dealloc(fobj.dwarf_handle.get(), ref, DW_DLA_DIE);
+ }
+
+ if (!context.has_type && context.has_name) {
+ context.text.insert(0, "void ");
+ context.has_type = true;
+ }
+ }
+
+ // Resolve the function return type and parameters
+ static void set_function_parameters(std::string &function_name,
+ std::vector<std::string> &ns,
+ dwarf_fileobject &fobj, Dwarf_Die die) {
+ Dwarf_Debug dwarf = fobj.dwarf_handle.get();
+ Dwarf_Error error = DW_DLE_NE;
+ Dwarf_Die current_die = 0;
+ std::string parameters;
+ bool has_spec = true;
+ // Check if we have a spec DIE. If we do we use it as it contains
+ // more information, like parameter names.
+ Dwarf_Die spec_die = get_spec_die(fobj, die);
+ if (!spec_die) {
+ has_spec = false;
+ spec_die = die;
+ }
+
+ std::vector<std::string>::const_iterator it = ns.begin();
+ std::string ns_name;
+ for (it = ns.begin(); it < ns.end(); ++it) {
+ ns_name.append(*it).append("::");
+ }
+
+ if (!ns_name.empty()) {
+ function_name.insert(0, ns_name);
+ }
+
+ // See if we have a function return type. It can be either on the
+ // current die or in its spec one (usually true for inlined functions)
+ std::string return_type =
+ get_referenced_die_name(dwarf, die, DW_AT_type, true);
+ if (return_type.empty()) {
+ return_type = get_referenced_die_name(dwarf, spec_die, DW_AT_type, true);
+ }
+ if (!return_type.empty()) {
+ return_type.append(" ");
+ function_name.insert(0, return_type);
+ }
+
+ if (dwarf_child(spec_die, ¤t_die, &error) == DW_DLV_OK) {
+ for (;;) {
+ Dwarf_Die sibling_die = 0;
+
+ Dwarf_Half tag_value;
+ dwarf_tag(current_die, &tag_value, &error);
+
+ if (tag_value == DW_TAG_formal_parameter) {
+ // Ignore artificial (ie, compiler generated) parameters
+ bool is_artificial = false;
+ Dwarf_Attribute attr_mem;
+ if (dwarf_attr(current_die, DW_AT_artificial, &attr_mem, &error) ==
+ DW_DLV_OK) {
+ Dwarf_Bool flag = 0;
+ if (dwarf_formflag(attr_mem, &flag, &error) == DW_DLV_OK) {
+ is_artificial = flag != 0;
+ }
+ dwarf_dealloc(dwarf, attr_mem, DW_DLA_ATTR);
+ }
+
+ if (!is_artificial) {
+ type_context_t context;
+ set_parameter_string(fobj, current_die, context);
+
+ if (parameters.empty()) {
+ parameters.append("(");
+ } else {
+ parameters.append(", ");
+ }
+ parameters.append(context.text);
+ }
+ }
+
+ int result = dwarf_siblingof(dwarf, current_die, &sibling_die, &error);
+ if (result == DW_DLV_ERROR) {
+ break;
+ } else if (result == DW_DLV_NO_ENTRY) {
+ break;
+ }
+
+ if (current_die != die) {
+ dwarf_dealloc(dwarf, current_die, DW_DLA_DIE);
+ current_die = 0;
+ }
+
+ current_die = sibling_die;
+ }
+ }
+ if (parameters.empty())
+ parameters = "(";
+ parameters.append(")");
+
+ // If we got a spec DIE we need to deallocate it
+ if (has_spec)
+ dwarf_dealloc(dwarf, spec_die, DW_DLA_DIE);
+
+ function_name.append(parameters);
+ }
+
+ // defined here because in C++98, template function cannot take locally
+ // defined types... grrr.
+ struct inliners_search_cb {
+ void operator()(Dwarf_Die die, std::vector<std::string> &ns) {
+ Dwarf_Error error = DW_DLE_NE;
+ Dwarf_Half tag_value;
+ Dwarf_Attribute attr_mem;
+ Dwarf_Debug dwarf = fobj.dwarf_handle.get();
+
+ dwarf_tag(die, &tag_value, &error);
+
+ switch (tag_value) {
+ char *name;
+ case DW_TAG_subprogram:
+ if (!trace.source.function.empty())
+ break;
+ if (dwarf_diename(die, &name, &error) == DW_DLV_OK) {
+ trace.source.function = std::string(name);
+ dwarf_dealloc(dwarf, name, DW_DLA_STRING);
+ } else {
+ // We don't have a function name in this DIE.
+ // Check if there is a referenced non-defining
+ // declaration.
+ trace.source.function =
+ get_referenced_die_name(dwarf, die, DW_AT_abstract_origin, true);
+ if (trace.source.function.empty()) {
+ trace.source.function =
+ get_referenced_die_name(dwarf, die, DW_AT_specification, true);
+ }
+ }
+
+ // Append the function parameters, if available
+ set_function_parameters(trace.source.function, ns, fobj, die);
+
+ // If the object function name is empty, it's possible that
+ // there is no dynamic symbol table (maybe the executable
+ // was stripped or not built with -rdynamic). See if we have
+ // a DWARF linkage name to use instead. We try both
+ // linkage_name and MIPS_linkage_name because the MIPS tag
+ // was the unofficial one until it was adopted in DWARF4.
+ // Old gcc versions generate MIPS_linkage_name
+ if (trace.object_function.empty()) {
+ details::demangler demangler;
+
+ if (dwarf_attr(die, DW_AT_linkage_name, &attr_mem, &error) !=
+ DW_DLV_OK) {
+ if (dwarf_attr(die, DW_AT_MIPS_linkage_name, &attr_mem, &error) !=
+ DW_DLV_OK) {
+ break;
+ }
+ }
+
+ char *linkage;
+ if (dwarf_formstring(attr_mem, &linkage, &error) == DW_DLV_OK) {
+ trace.object_function = demangler.demangle(linkage);
+ dwarf_dealloc(dwarf, linkage, DW_DLA_STRING);
+ }
+ dwarf_dealloc(dwarf, attr_mem, DW_DLA_ATTR);
+ }
+ break;
+
+ case DW_TAG_inlined_subroutine:
+ ResolvedTrace::SourceLoc sloc;
+
+ if (dwarf_diename(die, &name, &error) == DW_DLV_OK) {
+ sloc.function = std::string(name);
+ dwarf_dealloc(dwarf, name, DW_DLA_STRING);
+ } else {
+ // We don't have a name for this inlined DIE, it could
+ // be that there is an abstract origin instead.
+ // Get the DW_AT_abstract_origin value, which is a
+ // reference to the source DIE and try to get its name
+ sloc.function =
+ get_referenced_die_name(dwarf, die, DW_AT_abstract_origin, true);
+ }
+
+ set_function_parameters(sloc.function, ns, fobj, die);
+
+ std::string file = die_call_file(dwarf, die, cu_die);
+ if (!file.empty())
+ sloc.filename = file;
+
+ Dwarf_Unsigned number = 0;
+ if (dwarf_attr(die, DW_AT_call_line, &attr_mem, &error) == DW_DLV_OK) {
+ if (dwarf_formudata(attr_mem, &number, &error) == DW_DLV_OK) {
+ sloc.line = number;
+ }
+ dwarf_dealloc(dwarf, attr_mem, DW_DLA_ATTR);
+ }
+
+ if (dwarf_attr(die, DW_AT_call_column, &attr_mem, &error) ==
+ DW_DLV_OK) {
+ if (dwarf_formudata(attr_mem, &number, &error) == DW_DLV_OK) {
+ sloc.col = number;
+ }
+ dwarf_dealloc(dwarf, attr_mem, DW_DLA_ATTR);
+ }
+
+ trace.inliners.push_back(sloc);
+ break;
+ };
+ }
+ ResolvedTrace &trace;
+ dwarf_fileobject &fobj;
+ Dwarf_Die cu_die;
+ inliners_search_cb(ResolvedTrace &t, dwarf_fileobject &f, Dwarf_Die c)
+ : trace(t), fobj(f), cu_die(c) {}
+ };
+
+ static Dwarf_Die find_fundie_by_pc(dwarf_fileobject &fobj,
+ Dwarf_Die parent_die, Dwarf_Addr pc,
+ Dwarf_Die result) {
+ Dwarf_Die current_die = 0;
+ Dwarf_Error error = DW_DLE_NE;
+ Dwarf_Debug dwarf = fobj.dwarf_handle.get();
+
+ if (dwarf_child(parent_die, ¤t_die, &error) != DW_DLV_OK) {
+ return NULL;
+ }
+
+ for (;;) {
+ Dwarf_Die sibling_die = 0;
+ Dwarf_Half tag_value;
+ dwarf_tag(current_die, &tag_value, &error);
+
+ switch (tag_value) {
+ case DW_TAG_subprogram:
+ case DW_TAG_inlined_subroutine:
+ if (die_has_pc(fobj, current_die, pc)) {
+ return current_die;
+ }
+ };
+ bool declaration = false;
+ Dwarf_Attribute attr_mem;
+ if (dwarf_attr(current_die, DW_AT_declaration, &attr_mem, &error) ==
+ DW_DLV_OK) {
+ Dwarf_Bool flag = 0;
+ if (dwarf_formflag(attr_mem, &flag, &error) == DW_DLV_OK) {
+ declaration = flag != 0;
+ }
+ dwarf_dealloc(dwarf, attr_mem, DW_DLA_ATTR);
+ }
+
+ if (!declaration) {
+ // let's be curious and look deeper in the tree, functions are
+ // not necessarily at the first level, but might be nested
+ // inside a namespace, structure, a function, an inlined
+ // function etc.
+ Dwarf_Die die_mem = 0;
+ Dwarf_Die indie = find_fundie_by_pc(fobj, current_die, pc, die_mem);
+ if (indie) {
+ result = die_mem;
+ return result;
+ }
+ }
+
+ int res = dwarf_siblingof(dwarf, current_die, &sibling_die, &error);
+ if (res == DW_DLV_ERROR) {
+ return NULL;
+ } else if (res == DW_DLV_NO_ENTRY) {
+ break;
+ }
+
+ if (current_die != parent_die) {
+ dwarf_dealloc(dwarf, current_die, DW_DLA_DIE);
+ current_die = 0;
+ }
+
+ current_die = sibling_die;
+ }
+ return NULL;
+ }
+
+ template <typename CB>
+ static bool deep_first_search_by_pc(dwarf_fileobject &fobj,
+ Dwarf_Die parent_die, Dwarf_Addr pc,
+ std::vector<std::string> &ns, CB cb) {
+ Dwarf_Die current_die = 0;
+ Dwarf_Debug dwarf = fobj.dwarf_handle.get();
+ Dwarf_Error error = DW_DLE_NE;
+
+ if (dwarf_child(parent_die, ¤t_die, &error) != DW_DLV_OK) {
+ return false;
+ }
+
+ bool branch_has_pc = false;
+ bool has_namespace = false;
+ for (;;) {
+ Dwarf_Die sibling_die = 0;
+
+ Dwarf_Half tag;
+ if (dwarf_tag(current_die, &tag, &error) == DW_DLV_OK) {
+ if (tag == DW_TAG_namespace || tag == DW_TAG_class_type) {
+ char *ns_name = NULL;
+ if (dwarf_diename(current_die, &ns_name, &error) == DW_DLV_OK) {
+ if (ns_name) {
+ ns.push_back(std::string(ns_name));
+ } else {
+ ns.push_back("<unknown>");
+ }
+ dwarf_dealloc(dwarf, ns_name, DW_DLA_STRING);
+ } else {
+ ns.push_back("<unknown>");
+ }
+ has_namespace = true;
+ }
+ }
+
+ bool declaration = false;
+ Dwarf_Attribute attr_mem;
+ if (tag != DW_TAG_class_type &&
+ dwarf_attr(current_die, DW_AT_declaration, &attr_mem, &error) ==
+ DW_DLV_OK) {
+ Dwarf_Bool flag = 0;
+ if (dwarf_formflag(attr_mem, &flag, &error) == DW_DLV_OK) {
+ declaration = flag != 0;
+ }
+ dwarf_dealloc(dwarf, attr_mem, DW_DLA_ATTR);
+ }
+
+ if (!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(fobj, current_die, pc, ns, cb);
+ }
+
+ if (!branch_has_pc) {
+ branch_has_pc = die_has_pc(fobj, current_die, pc);
+ }
+
+ if (branch_has_pc) {
+ cb(current_die, ns);
+ }
+
+ int result = dwarf_siblingof(dwarf, current_die, &sibling_die, &error);
+ if (result == DW_DLV_ERROR) {
+ return false;
+ } else if (result == DW_DLV_NO_ENTRY) {
+ break;
+ }
+
+ if (current_die != parent_die) {
+ dwarf_dealloc(dwarf, current_die, DW_DLA_DIE);
+ current_die = 0;
+ }
+
+ if (has_namespace) {
+ has_namespace = false;
+ ns.pop_back();
+ }
+ current_die = sibling_die;
+ }
+
+ if (has_namespace) {
+ ns.pop_back();
+ }
+ return branch_has_pc;
+ }
+
+ static std::string die_call_file(Dwarf_Debug dwarf, Dwarf_Die die,
+ Dwarf_Die cu_die) {
+ Dwarf_Attribute attr_mem;
+ Dwarf_Error error = DW_DLE_NE;
+ Dwarf_Unsigned file_index;
+
+ std::string file;
+
+ if (dwarf_attr(die, DW_AT_call_file, &attr_mem, &error) == DW_DLV_OK) {
+ if (dwarf_formudata(attr_mem, &file_index, &error) != DW_DLV_OK) {
+ file_index = 0;
+ }
+ dwarf_dealloc(dwarf, attr_mem, DW_DLA_ATTR);
+
+ if (file_index == 0) {
+ return file;
+ }
+
+ char **srcfiles = 0;
+ Dwarf_Signed file_count = 0;
+ if (dwarf_srcfiles(cu_die, &srcfiles, &file_count, &error) == DW_DLV_OK) {
+ if (file_count > 0 && file_index <= static_cast<Dwarf_Unsigned>(file_count)) {
+ file = std::string(srcfiles[file_index - 1]);
+ }
+
+ // Deallocate all strings!
+ for (int i = 0; i < file_count; ++i) {
+ dwarf_dealloc(dwarf, srcfiles[i], DW_DLA_STRING);
+ }
+ dwarf_dealloc(dwarf, srcfiles, DW_DLA_LIST);
+ }
+ }
+ return file;
+ }
+
+ Dwarf_Die find_die(dwarf_fileobject &fobj, Dwarf_Addr addr) {
+ // Let's get to work! First see if we have a debug_aranges section so
+ // we can speed up the search
+
+ Dwarf_Debug dwarf = fobj.dwarf_handle.get();
+ Dwarf_Error error = DW_DLE_NE;
+ Dwarf_Arange *aranges;
+ Dwarf_Signed arange_count;
+
+ Dwarf_Die returnDie;
+ bool found = false;
+ if (dwarf_get_aranges(dwarf, &aranges, &arange_count, &error) !=
+ DW_DLV_OK) {
+ aranges = NULL;
+ }
+
+ if (aranges) {
+ // We have aranges. Get the one where our address is.
+ Dwarf_Arange arange;
+ if (dwarf_get_arange(aranges, arange_count, addr, &arange, &error) ==
+ DW_DLV_OK) {
+
+ // We found our address. Get the compilation-unit DIE offset
+ // represented by the given address range.
+ Dwarf_Off cu_die_offset;
+ if (dwarf_get_cu_die_offset(arange, &cu_die_offset, &error) ==
+ DW_DLV_OK) {
+ // Get the DIE at the offset returned by the aranges search.
+ // We set is_info to 1 to specify that the offset is from
+ // the .debug_info section (and not .debug_types)
+ int dwarf_result =
+ dwarf_offdie_b(dwarf, cu_die_offset, 1, &returnDie, &error);
+
+ found = dwarf_result == DW_DLV_OK;
+ }
+ dwarf_dealloc(dwarf, arange, DW_DLA_ARANGE);
+ }
+ }
+
+ if (found)
+ return returnDie; // The caller is responsible for freeing the die
+
+ // The search for aranges failed. Try to find our address by scanning
+ // all compilation units.
+ Dwarf_Unsigned next_cu_header;
+ Dwarf_Half tag = 0;
+ returnDie = 0;
+
+ while (!found &&
+ dwarf_next_cu_header_d(dwarf, 1, 0, 0, 0, 0, 0, 0, 0, 0,
+ &next_cu_header, 0, &error) == DW_DLV_OK) {
+
+ if (returnDie)
+ dwarf_dealloc(dwarf, returnDie, DW_DLA_DIE);
+
+ if (dwarf_siblingof(dwarf, 0, &returnDie, &error) == DW_DLV_OK) {
+ if ((dwarf_tag(returnDie, &tag, &error) == DW_DLV_OK) &&
+ tag == DW_TAG_compile_unit) {
+ if (die_has_pc(fobj, returnDie, addr)) {
+ found = true;
+ }
+ }
+ }
+ }
+
+ if (found) {
+ while (dwarf_next_cu_header_d(dwarf, 1, 0, 0, 0, 0, 0, 0, 0, 0,
+ &next_cu_header, 0, &error) == DW_DLV_OK) {
+ // Reset the cu header state. Libdwarf's next_cu_header API
+ // keeps its own iterator per Dwarf_Debug that can't be reset.
+ // We need to keep fetching elements until the end.
+ }
+ }
+
+ if (found)
+ return returnDie;
+
+ // We couldn't find any compilation units with ranges or a high/low pc.
+ // Try again by looking at all DIEs in all compilation units.
+ Dwarf_Die cudie;
+ while (dwarf_next_cu_header_d(dwarf, 1, 0, 0, 0, 0, 0, 0, 0, 0,
+ &next_cu_header, 0, &error) == DW_DLV_OK) {
+ if (dwarf_siblingof(dwarf, 0, &cudie, &error) == DW_DLV_OK) {
+ Dwarf_Die die_mem = 0;
+ Dwarf_Die resultDie = find_fundie_by_pc(fobj, cudie, addr, die_mem);
+
+ if (resultDie) {
+ found = true;
+ break;
+ }
+ }
+ }
+
+ if (found) {
+ while (dwarf_next_cu_header_d(dwarf, 1, 0, 0, 0, 0, 0, 0, 0, 0,
+ &next_cu_header, 0, &error) == DW_DLV_OK) {
+ // Reset the cu header state. Libdwarf's next_cu_header API
+ // keeps its own iterator per Dwarf_Debug that can't be reset.
+ // We need to keep fetching elements until the end.
+ }
+ }
+
+ if (found)
+ return cudie;
+
+ // We failed.
+ return NULL;
+ }
+};
+#endif // BACKWARD_HAS_DWARF == 1
+
+template <>
+class TraceResolverImpl<system_tag::linux_tag>
+ : public TraceResolverLinuxImpl<trace_resolver_tag::current> {};
+
+#endif // BACKWARD_SYSTEM_LINUX
+
+#ifdef BACKWARD_SYSTEM_DARWIN
+
+template <typename STACKTRACE_TAG> class TraceResolverDarwinImpl;
+
+template <>
+class TraceResolverDarwinImpl<trace_resolver_tag::backtrace_symbol>
+ : public TraceResolverImplBase {
+public:
+ void load_addresses(void *const*addresses, int address_count) override {
+ if (address_count == 0) {
+ return;
+ }
+ _symbols.reset(backtrace_symbols(addresses, address_count));
+ }
+
+ ResolvedTrace resolve(ResolvedTrace trace) override {
+ // parse:
+ // <n> <file> <addr> <mangled-name> + <offset>
+ char *filename = _symbols[trace.idx];
+
+ // skip "<n> "
+ while (*filename && *filename != ' ')
+ filename++;
+ while (*filename == ' ')
+ filename++;
+
+ // find start of <mangled-name> from end (<file> may contain a space)
+ char *p = filename + strlen(filename) - 1;
+ // skip to start of " + <offset>"
+ while (p > filename && *p != ' ')
+ p--;
+ while (p > filename && *p == ' ')
+ p--;
+ while (p > filename && *p != ' ')
+ p--;
+ while (p > filename && *p == ' ')
+ p--;
+ char *funcname_end = p + 1;
+
+ // skip to start of "<manged-name>"
+ while (p > filename && *p != ' ')
+ p--;
+ char *funcname = p + 1;
+
+ // skip to start of " <addr> "
+ while (p > filename && *p == ' ')
+ p--;
+ while (p > filename && *p != ' ')
+ p--;
+ while (p > filename && *p == ' ')
+ p--;
+
+ // skip "<file>", handling the case where it contains a
+ char *filename_end = p + 1;
+ if (p == filename) {
+ // something went wrong, give up
+ filename_end = filename + strlen(filename);
+ funcname = filename_end;
+ }
+ trace.object_filename.assign(
+ filename, filename_end); // ok even if filename_end is the ending \0
+ // (then we assign entire string)
+
+ if (*funcname) { // if it's not end of string
+ *funcname_end = '\0';
+
+ trace.object_function = this->demangle(funcname);
+ trace.object_function += " ";
+ trace.object_function += (funcname_end + 1);
+ trace.source.function = trace.object_function; // we cannot do better.
+ }
+ return trace;
+ }
+
+private:
+ details::handle<char **> _symbols;
+};
+
+template <>
+class TraceResolverImpl<system_tag::darwin_tag>
+ : public TraceResolverDarwinImpl<trace_resolver_tag::current> {};
+
+#endif // BACKWARD_SYSTEM_DARWIN
+
+#ifdef BACKWARD_SYSTEM_WINDOWS
+
+// Load all symbol info
+// Based on:
+// https://stackoverflow.com/questions/6205981/windows-c-stack-trace-from-a-running-app/28276227#28276227
+
+struct module_data {
+ std::string image_name;
+ std::string module_name;
+ void *base_address;
+ DWORD load_size;
+};
+
+class get_mod_info {
+ HANDLE process;
+ static const int buffer_length = 4096;
+
+public:
+ get_mod_info(HANDLE h) : process(h) {}
+
+ module_data operator()(HMODULE module) {
+ module_data ret;
+ char temp[buffer_length];
+ MODULEINFO mi;
+
+ GetModuleInformation(process, module, &mi, sizeof(mi));
+ ret.base_address = mi.lpBaseOfDll;
+ ret.load_size = mi.SizeOfImage;
+
+ GetModuleFileNameExA(process, module, temp, sizeof(temp));
+ ret.image_name = temp;
+ GetModuleBaseNameA(process, module, temp, sizeof(temp));
+ ret.module_name = temp;
+ std::vector<char> img(ret.image_name.begin(), ret.image_name.end());
+ std::vector<char> mod(ret.module_name.begin(), ret.module_name.end());
+ SymLoadModule64(process, 0, &img[0], &mod[0], (DWORD64)ret.base_address,
+ ret.load_size);
+ return ret;
+ }
+};
+
+template <> class TraceResolverImpl<system_tag::windows_tag>
+ : public TraceResolverImplBase {
+public:
+ TraceResolverImpl() {
+
+ HANDLE process = GetCurrentProcess();
+
+ std::vector<module_data> modules;
+ DWORD cbNeeded;
+ std::vector<HMODULE> module_handles(1);
+ SymInitialize(process, NULL, false);
+ DWORD symOptions = SymGetOptions();
+ symOptions |= SYMOPT_LOAD_LINES | SYMOPT_UNDNAME;
+ SymSetOptions(symOptions);
+ EnumProcessModules(process, &module_handles[0],
+ module_handles.size() * sizeof(HMODULE), &cbNeeded);
+ module_handles.resize(cbNeeded / sizeof(HMODULE));
+ EnumProcessModules(process, &module_handles[0],
+ module_handles.size() * sizeof(HMODULE), &cbNeeded);
+ std::transform(module_handles.begin(), module_handles.end(),
+ std::back_inserter(modules), get_mod_info(process));
+ void *base = modules[0].base_address;
+ IMAGE_NT_HEADERS *h = ImageNtHeader(base);
+ image_type = h->FileHeader.Machine;
+ }
+
+ static const int max_sym_len = 255;
+ struct symbol_t {
+ SYMBOL_INFO sym;
+ char buffer[max_sym_len];
+ } sym;
+
+ DWORD64 displacement;
+
+ ResolvedTrace resolve(ResolvedTrace t) override {
+ HANDLE process = GetCurrentProcess();
+
+ char name[256];
+
+ memset(&sym, 0, sizeof(sym));
+ sym.sym.SizeOfStruct = sizeof(SYMBOL_INFO);
+ sym.sym.MaxNameLen = max_sym_len;
+
+ if (!SymFromAddr(process, (ULONG64)t.addr, &displacement, &sym.sym)) {
+ // TODO: error handling everywhere
+ char* lpMsgBuf;
+ DWORD dw = GetLastError();
+
+ if (FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER |
+ FORMAT_MESSAGE_FROM_SYSTEM |
+ FORMAT_MESSAGE_IGNORE_INSERTS,
+ NULL, dw, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+ (char*)&lpMsgBuf, 0, NULL)) {
+ std::fprintf(stderr, "%s\n", lpMsgBuf);
+ LocalFree(lpMsgBuf);
+ }
+
+ // abort();
+ }
+ UnDecorateSymbolName(sym.sym.Name, (PSTR)name, 256, UNDNAME_COMPLETE);
+
+ DWORD offset = 0;
+ IMAGEHLP_LINE line;
+ if (SymGetLineFromAddr(process, (ULONG64)t.addr, &offset, &line)) {
+ t.object_filename = line.FileName;
+ t.source.filename = line.FileName;
+ t.source.line = line.LineNumber;
+ t.source.col = offset;
+ }
+
+ t.source.function = name;
+ t.object_filename = "";
+ t.object_function = name;
+
+ return t;
+ }
+
+ DWORD machine_type() const { return image_type; }
+
+private:
+ DWORD image_type;
+};
+
+#endif
+
+class TraceResolver : public TraceResolverImpl<system_tag::current_tag> {};
+
+/*************** CODE SNIPPET ***************/
+
+class SourceFile {
+public:
+ typedef std::vector<std::pair<unsigned, std::string>> lines_t;
+
+ SourceFile() {}
+ SourceFile(const std::string &path) {
+ // 1. If BACKWARD_CXX_SOURCE_PREFIXES is set then assume it contains
+ // a colon-separated list of path prefixes. Try prepending each
+ // to the given path until a valid file is found.
+ const std::vector<std::string> &prefixes = get_paths_from_env_variable();
+ for (size_t i = 0; i < prefixes.size(); ++i) {
+ // Double slashes (//) should not be a problem.
+ std::string new_path = prefixes[i] + '/' + path;
+ _file.reset(new std::ifstream(new_path.c_str()));
+ if (is_open())
+ break;
+ }
+ // 2. If no valid file found then fallback to opening the path as-is.
+ if (!_file || !is_open()) {
+ _file.reset(new std::ifstream(path.c_str()));
+ }
+ }
+ bool is_open() const { return _file->is_open(); }
+
+ lines_t &get_lines(unsigned line_start, unsigned 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;
+ unsigned line_idx;
+
+ for (line_idx = 1; line_idx < line_start; ++line_idx) {
+ std::getline(*_file, line);
+ if (!*_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 (!*_file) {
+ return lines;
+ }
+ if (!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(unsigned line_start, unsigned 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 !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 !(std::find_if(p.second.begin(), p.second.end(), not_isspace()) ==
+ p.second.end());
+ }
+ };
+
+ void swap(SourceFile &b) { _file.swap(b._file); }
+
+#ifdef BACKWARD_ATLEAST_CXX11
+ SourceFile(SourceFile &&from) : _file(nullptr) { 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<SourceFile &>(from));
+ }
+ SourceFile &operator=(const SourceFile &from) {
+ // some sort of poor man's move semantic.
+ swap(const_cast<SourceFile &>(from));
+ return *this;
+ }
+#endif
+
+private:
+ details::handle<std::ifstream *, details::default_delete<std::ifstream *>>
+ _file;
+
+ std::vector<std::string> get_paths_from_env_variable_impl() {
+ std::vector<std::string> paths;
+ const char *prefixes_str = std::getenv("BACKWARD_CXX_SOURCE_PREFIXES");
+ if (prefixes_str && prefixes_str[0]) {
+ paths = details::split_source_prefixes(prefixes_str);
+ }
+ return paths;
+ }
+
+ const std::vector<std::string> &get_paths_from_env_variable() {
+ static std::vector<std::string> paths = get_paths_from_env_variable_impl();
+ return paths;
+ }
+
+#ifdef BACKWARD_ATLEAST_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, unsigned line_start,
+ unsigned context_size) {
+
+ SourceFile &src_file = get_src_file(filename);
+ unsigned start = line_start - context_size / 2;
+ return src_file.get_lines(start, context_size);
+ }
+
+ lines_t get_combined_snippet(const std::string &filename_a, unsigned line_a,
+ const std::string &filename_b, unsigned line_b,
+ unsigned 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, unsigned line_a,
+ unsigned line_b, unsigned context_size) {
+ SourceFile &src_file = get_src_file(filename);
+
+ using std::max;
+ using std::min;
+ unsigned a = min(line_a, line_b);
+ unsigned 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<std::string, SourceFile>::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 ***************/
+
+namespace ColorMode {
+enum type { automatic, never, always };
+}
+
+class cfile_streambuf : public std::streambuf {
+public:
+ cfile_streambuf(FILE *_sink) : sink(_sink) {}
+ int_type underflow() override { return traits_type::eof(); }
+ int_type overflow(int_type ch) override {
+ if (traits_type::not_eof(ch) && fputc(ch, sink) != EOF) {
+ return ch;
+ }
+ return traits_type::eof();
+ }
+
+ std::streamsize xsputn(const char_type *s, std::streamsize count) override {
+ return static_cast<std::streamsize>(
+ fwrite(s, sizeof *s, static_cast<size_t>(count), sink));
+ }
+
+#ifdef BACKWARD_ATLEAST_CXX11
+public:
+ cfile_streambuf(const cfile_streambuf &) = delete;
+ cfile_streambuf &operator=(const cfile_streambuf &) = delete;
+#else
+private:
+ cfile_streambuf(const cfile_streambuf &);
+ cfile_streambuf &operator=(const cfile_streambuf &);
+#endif
+
+private:
+ FILE *sink;
+ std::vector<char> buffer;
+};
+
+#ifdef BACKWARD_SYSTEM_LINUX
+
+namespace Color {
+enum type { yellow = 33, purple = 35, reset = 39 };
+} // namespace Color
+
+class Colorize {
+public:
+ Colorize(std::ostream &os) : _os(os), _reset(false), _enabled(false) {}
+
+ void activate(ColorMode::type mode) { _enabled = mode == ColorMode::always; }
+
+ void activate(ColorMode::type mode, FILE *fp) { activate(mode, fileno(fp)); }
+
+ void set_color(Color::type ccode) {
+ if (!_enabled)
+ return;
+
+ // I assume that the terminal can handle basic colors. Seriously I
+ // don't want to deal with all the termcap shit.
+ _os << "\033[" << static_cast<int>(ccode) << "m";
+ _reset = (ccode != Color::reset);
+ }
+
+ ~Colorize() {
+ if (_reset) {
+ set_color(Color::reset);
+ }
+ }
+
+private:
+ void activate(ColorMode::type mode, int fd) {
+ activate(mode == ColorMode::automatic && isatty(fd) ? ColorMode::always
+ : mode);
+ }
+
+ std::ostream &_os;
+ bool _reset;
+ bool _enabled;
+};
+
+#else // ndef BACKWARD_SYSTEM_LINUX
+
+namespace Color {
+enum type { yellow = 0, purple = 0, reset = 0 };
+} // namespace Color
+
+class Colorize {
+public:
+ Colorize(std::ostream &) {}
+ void activate(ColorMode::type) {}
+ void activate(ColorMode::type, FILE *) {}
+ void set_color(Color::type) {}
+};
+
+#endif // BACKWARD_SYSTEM_LINUX
+
+class Printer {
+public:
+ bool snippet;
+ ColorMode::type color_mode;
+ bool address;
+ bool object;
+ int inliner_context_size;
+ int trace_context_size;
+
+ Printer()
+ : snippet(true), color_mode(ColorMode::automatic), address(false),
+ object(false), inliner_context_size(5), trace_context_size(7) {}
+
+ template <typename ST> FILE *print(ST &st, FILE *fp = stderr) {
+ cfile_streambuf obuf(fp);
+ std::ostream os(&obuf);
+ Colorize colorize(os);
+ colorize.activate(color_mode, fp);
+ print_stacktrace(st, os, colorize);
+ return fp;
+ }
+
+ template <typename ST> std::ostream &print(ST &st, std::ostream &os) {
+ Colorize colorize(os);
+ colorize.activate(color_mode);
+ print_stacktrace(st, os, colorize);
+ return os;
+ }
+
+ template <typename IT>
+ FILE *print(IT begin, IT end, FILE *fp = stderr, size_t thread_id = 0) {
+ cfile_streambuf obuf(fp);
+ std::ostream os(&obuf);
+ Colorize colorize(os);
+ colorize.activate(color_mode, fp);
+ print_stacktrace(begin, end, os, thread_id, colorize);
+ return fp;
+ }
+
+ template <typename IT>
+ std::ostream &print(IT begin, IT end, std::ostream &os,
+ size_t thread_id = 0) {
+ Colorize colorize(os);
+ colorize.activate(color_mode);
+ print_stacktrace(begin, end, os, thread_id, colorize);
+ return os;
+ }
+
+ TraceResolver const &resolver() const { return _resolver; }
+
+private:
+ TraceResolver _resolver;
+ SnippetFactory _snippets;
+
+ template <typename ST>
+ void print_stacktrace(ST &st, std::ostream &os, Colorize &colorize) {
+ print_header(os, st.thread_id());
+ _resolver.load_stacktrace(st);
+ for (size_t trace_idx = st.size(); trace_idx > 0; --trace_idx) {
+ print_trace(os, _resolver.resolve(st[trace_idx - 1]), colorize);
+ }
+ }
+
+ template <typename IT>
+ void print_stacktrace(IT begin, IT end, std::ostream &os, size_t thread_id,
+ Colorize &colorize) {
+ print_header(os, thread_id);
+ for (; begin != end; ++begin) {
+ print_trace(os, *begin, colorize);
+ }
+ }
+
+ void print_header(std::ostream &os, size_t thread_id) {
+ os << "Stack trace (most recent call last)";
+ if (thread_id) {
+ os << " in thread " << thread_id;
+ }
+ os << ":\n";
+ }
+
+ void print_trace(std::ostream &os, const ResolvedTrace &trace,
+ Colorize &colorize) {
+ os << "#" << std::left << std::setw(2) << trace.idx << std::right;
+ bool already_indented = true;
+
+ if (!trace.source.filename.size() || object) {
+ os << " Object \"" << trace.object_filename << "\", at " << trace.addr
+ << ", in " << trace.object_function << "\n";
+ already_indented = false;
+ }
+
+ for (size_t inliner_idx = trace.inliners.size(); inliner_idx > 0;
+ --inliner_idx) {
+ if (!already_indented) {
+ 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,
+ inliner_context_size);
+ }
+ already_indented = false;
+ }
+
+ if (trace.source.filename.size()) {
+ if (!already_indented) {
+ os << " ";
+ }
+ print_source_loc(os, " ", trace.source, trace.addr);
+ if (snippet) {
+ print_snippet(os, " ", trace.source, colorize, Color::yellow,
+ trace_context_size);
+ }
+ }
+ }
+
+ void print_snippet(std::ostream &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,
+ static_cast<unsigned>(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);
+ os << indent << ">";
+ } else {
+ os << indent << " ";
+ }
+ os << std::setw(4) << it->first << ": " << it->second << "\n";
+ if (it->first == source_loc.line) {
+ colorize.set_color(Color::reset);
+ }
+ }
+ }
+
+ void print_source_loc(std::ostream &os, const char *indent,
+ const ResolvedTrace::SourceLoc &source_loc,
+ void *addr = nullptr) {
+ os << indent << "Source \"" << source_loc.filename << "\", line "
+ << source_loc.line << ", in " << source_loc.function;
+
+ if (address && addr != nullptr) {
+ os << " [" << addr << "]";
+ }
+ os << "\n";
+ }
+};
+
+/*************** SIGNALS HANDLING ***************/
+
+#if defined(BACKWARD_SYSTEM_LINUX) || defined(BACKWARD_SYSTEM_DARWIN)
+
+class SignalHandling {
+public:
+ static std::vector<int> make_default_signals() {
+ const int posix_signals[] = {
+ // Signals for which the default action is "Core".
+ SIGABRT, // Abort signal from abort(3)
+ SIGBUS, // Bus error (bad memory access)
+ SIGFPE, // Floating point exception
+ SIGILL, // Illegal Instruction
+ SIGIOT, // IOT trap. A synonym for SIGABRT
+ SIGQUIT, // Quit from keyboard
+ SIGSEGV, // Invalid memory reference
+ SIGSYS, // Bad argument to routine (SVr4)
+ SIGTRAP, // Trace/breakpoint trap
+ SIGXCPU, // CPU time limit exceeded (4.2BSD)
+ SIGXFSZ, // File size limit exceeded (4.2BSD)
+#if defined(BACKWARD_SYSTEM_DARWIN)
+ SIGEMT, // emulation instruction executed
+#endif
+ };
+ return std::vector<int>(posix_signals,
+ posix_signals +
+ sizeof posix_signals / sizeof posix_signals[0]);
+ }
+
+ SignalHandling(const std::vector<int> &posix_signals = make_default_signals())
+ : _loaded(false) {
+ bool success = true;
+
+ const size_t stack_size = 1024 * 1024 * 8;
+ _stack_content.reset(static_cast<char *>(malloc(stack_size)));
+ if (_stack_content) {
+ stack_t ss;
+ ss.ss_sp = _stack_content.get();
+ ss.ss_size = stack_size;
+ ss.ss_flags = 0;
+ if (sigaltstack(&ss, nullptr) < 0) {
+ success = false;
+ }
+ } else {
+ success = false;
+ }
+
+ for (size_t i = 0; i < posix_signals.size(); ++i) {
+ struct sigaction action;
+ memset(&action, 0, sizeof action);
+ action.sa_flags =
+ static_cast<int>(SA_SIGINFO | SA_ONSTACK | SA_NODEFER | SA_RESETHAND);
+ sigfillset(&action.sa_mask);
+ sigdelset(&action.sa_mask, posix_signals[i]);
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdisabled-macro-expansion"
+#endif
+ action.sa_sigaction = &sig_handler;
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif
+
+ int r = sigaction(posix_signals[i], &action, nullptr);
+ if (r < 0)
+ success = false;
+ }
+
+ _loaded = success;
+ }
+
+ bool loaded() const { return _loaded; }
+
+ static void handleSignal(int, siginfo_t *info, void *_ctx) {
+ ucontext_t *uctx = static_cast<ucontext_t *>(_ctx);
+
+ StackTrace st;
+ void *error_addr = nullptr;
+#ifdef REG_RIP // x86_64
+ error_addr = reinterpret_cast<void *>(uctx->uc_mcontext.gregs[REG_RIP]);
+#elif defined(REG_EIP) // x86_32
+ error_addr = reinterpret_cast<void *>(uctx->uc_mcontext.gregs[REG_EIP]);
+#elif defined(__arm__)
+ error_addr = reinterpret_cast<void *>(uctx->uc_mcontext.arm_pc);
+#elif defined(__aarch64__)
+ #if defined(__APPLE__)
+ error_addr = reinterpret_cast<void *>(uctx->uc_mcontext->__ss.__pc);
+ #else
+ error_addr = reinterpret_cast<void *>(uctx->uc_mcontext.pc);
+ #endif
+#elif defined(__mips__)
+ error_addr = reinterpret_cast<void *>(
+ reinterpret_cast<struct sigcontext *>(&uctx->uc_mcontext)->sc_pc);
+#elif defined(__ppc__) || defined(__powerpc) || defined(__powerpc__) || \
+ defined(__POWERPC__)
+ error_addr = reinterpret_cast<void *>(uctx->uc_mcontext.regs->nip);
+#elif defined(__riscv)
+ error_addr = reinterpret_cast<void *>(uctx->uc_mcontext.__gregs[REG_PC]);
+#elif defined(__s390x__)
+ error_addr = reinterpret_cast<void *>(uctx->uc_mcontext.psw.addr);
+#elif defined(__APPLE__) && defined(__x86_64__)
+ error_addr = reinterpret_cast<void *>(uctx->uc_mcontext->__ss.__rip);
+#elif defined(__APPLE__)
+ error_addr = reinterpret_cast<void *>(uctx->uc_mcontext->__ss.__eip);
+#else
+#warning ":/ sorry, ain't know no nothing none not of your architecture!"
+#endif
+ if (error_addr) {
+ st.load_from(error_addr, 32, reinterpret_cast<void *>(uctx),
+ info->si_addr);
+ } else {
+ st.load_here(32, reinterpret_cast<void *>(uctx), info->si_addr);
+ }
+
+ Printer printer;
+ printer.address = true;
+ printer.print(st, stderr);
+
+#if _XOPEN_SOURCE >= 700 || _POSIX_C_SOURCE >= 200809L
+ psiginfo(info, nullptr);
+#else
+ (void)info;
+#endif
+ }
+
+private:
+ details::handle<char *> _stack_content;
+ bool _loaded;
+
+#ifdef __GNUC__
+ __attribute__((noreturn))
+#endif
+ static void
+ sig_handler(int signo, siginfo_t *info, void *_ctx) {
+ handleSignal(signo, info, _ctx);
+
+ // try to forward the signal.
+ raise(info->si_signo);
+
+ // terminate the process immediately.
+ puts("watf? exit");
+ _exit(EXIT_FAILURE);
+ }
+};
+
+#endif // BACKWARD_SYSTEM_LINUX || BACKWARD_SYSTEM_DARWIN
+
+#ifdef BACKWARD_SYSTEM_WINDOWS
+
+class SignalHandling {
+public:
+ SignalHandling(const std::vector<int> & = std::vector<int>())
+ : reporter_thread_([]() {
+ /* We handle crashes in a utility thread:
+ backward structures and some Windows functions called here
+ need stack space, which we do not have when we encounter a
+ stack overflow.
+ To support reporting stack traces during a stack overflow,
+ we create a utility thread at startup, which waits until a
+ crash happens or the program exits normally. */
+
+ {
+ std::unique_lock<std::mutex> lk(mtx());
+ cv().wait(lk, [] { return crashed() != crash_status::running; });
+ }
+ if (crashed() == crash_status::crashed) {
+ handle_stacktrace(skip_recs());
+ }
+ {
+ std::unique_lock<std::mutex> lk(mtx());
+ crashed() = crash_status::ending;
+ }
+ cv().notify_one();
+ }) {
+ SetUnhandledExceptionFilter(crash_handler);
+
+ signal(SIGABRT, signal_handler);
+ _set_abort_behavior(0, _WRITE_ABORT_MSG | _CALL_REPORTFAULT);
+
+ std::set_terminate(&terminator);
+#ifndef BACKWARD_ATLEAST_CXX17
+ std::set_unexpected(&terminator);
+#endif
+ _set_purecall_handler(&terminator);
+ _set_invalid_parameter_handler(&invalid_parameter_handler);
+ }
+ bool loaded() const { return true; }
+
+ ~SignalHandling() {
+ {
+ std::unique_lock<std::mutex> lk(mtx());
+ crashed() = crash_status::normal_exit;
+ }
+
+ cv().notify_one();
+
+ reporter_thread_.join();
+ }
+
+private:
+ static CONTEXT *ctx() {
+ static CONTEXT data;
+ return &data;
+ }
+
+ enum class crash_status { running, crashed, normal_exit, ending };
+
+ static crash_status &crashed() {
+ static crash_status data;
+ return data;
+ }
+
+ static std::mutex &mtx() {
+ static std::mutex data;
+ return data;
+ }
+
+ static std::condition_variable &cv() {
+ static std::condition_variable data;
+ return data;
+ }
+
+ static HANDLE &thread_handle() {
+ static HANDLE handle;
+ return handle;
+ }
+
+ std::thread reporter_thread_;
+
+ // TODO: how not to hardcode these?
+ static const constexpr int signal_skip_recs =
+#ifdef __clang__
+ // With clang, RtlCaptureContext also captures the stack frame of the
+ // current function Below that, there ar 3 internal Windows functions
+ 4
+#else
+ // With MSVC cl, RtlCaptureContext misses the stack frame of the current
+ // function The first entries during StackWalk are the 3 internal Windows
+ // functions
+ 3
+#endif
+ ;
+
+ static int &skip_recs() {
+ static int data;
+ return data;
+ }
+
+ static inline void terminator() {
+ crash_handler(signal_skip_recs);
+ abort();
+ }
+
+ static inline void signal_handler(int) {
+ crash_handler(signal_skip_recs);
+ abort();
+ }
+
+ static inline void __cdecl invalid_parameter_handler(const wchar_t *,
+ const wchar_t *,
+ const wchar_t *,
+ unsigned int,
+ uintptr_t) {
+ crash_handler(signal_skip_recs);
+ abort();
+ }
+
+ NOINLINE static LONG WINAPI crash_handler(EXCEPTION_POINTERS *info) {
+ // The exception info supplies a trace from exactly where the issue was,
+ // no need to skip records
+ crash_handler(0, info->ContextRecord);
+ return EXCEPTION_CONTINUE_SEARCH;
+ }
+
+ NOINLINE static void crash_handler(int skip, CONTEXT *ct = nullptr) {
+
+ if (ct == nullptr) {
+ RtlCaptureContext(ctx());
+ } else {
+ memcpy(ctx(), ct, sizeof(CONTEXT));
+ }
+ DuplicateHandle(GetCurrentProcess(), GetCurrentThread(),
+ GetCurrentProcess(), &thread_handle(), 0, FALSE,
+ DUPLICATE_SAME_ACCESS);
+
+ skip_recs() = skip;
+
+ {
+ std::unique_lock<std::mutex> lk(mtx());
+ crashed() = crash_status::crashed;
+ }
+
+ cv().notify_one();
+
+ {
+ std::unique_lock<std::mutex> lk(mtx());
+ cv().wait(lk, [] { return crashed() != crash_status::crashed; });
+ }
+ }
+
+ static void handle_stacktrace(int skip_frames = 0) {
+ // printer creates the TraceResolver, which can supply us a machine type
+ // for stack walking. Without this, StackTrace can only guess using some
+ // macros.
+ // StackTrace also requires that the PDBs are already loaded, which is done
+ // in the constructor of TraceResolver
+ Printer printer;
+
+ StackTrace st;
+ st.set_machine_type(printer.resolver().machine_type());
+ st.set_thread_handle(thread_handle());
+ st.load_here(32 + skip_frames, ctx());
+ st.skip_n_firsts(skip_frames);
+
+ printer.address = true;
+ printer.print(st, std::cerr);
+ }
+};
+
+#endif // BACKWARD_SYSTEM_WINDOWS
+
+#ifdef BACKWARD_SYSTEM_UNKNOWN
+
+class SignalHandling {
+public:
+ SignalHandling(const std::vector<int> & = std::vector<int>()) {}
+ bool init() { return false; }
+ bool loaded() { return false; }
+};
+
+#endif // BACKWARD_SYSTEM_UNKNOWN
+
+} // namespace backward
+
+#endif /* H_GUARD */
projects / rspamd.git / commitdiff