- std::vector<std::string> result;
-
- if (count == 0)
- return result;
-
- if (xbt_binary_name == nullptr)
- XBT_WARN("XBT not initialized, the backtrace will not be resolved.");
-
- // Drop the first one:
- loc++;
- count--;
-
- char** backtrace_syms = backtrace_symbols(loc, count);
- std::string binary_name = get_binary_path();
-
- if (binary_name.empty()) {
- for (std::size_t i = 0; i < count; i++)
- result.push_back(simgrid::xbt::string_printf("%p", loc[i]));
- return result;
- }
-
- // Create the system command for add2line:
- std::ostringstream stream;
- stream << ADDR2LINE << " -f -e " << binary_name << ' ';
- std::vector<std::string> addrs(count);
- for (std::size_t i = 0; i < count; i++) {
- /* retrieve this address */
- XBT_DEBUG("Retrieving address number %zu from '%s'", i, backtrace_syms[i]);
- char buff[256];
- snprintf(buff, 256, "%s", strchr(backtrace_syms[i], '[') + 1);
- char* p = strchr(buff, ']');
- *p = '\0';
- if (strcmp(buff, "(nil)"))
- addrs[i] = buff;
- else
- addrs[i] = "0x0";
- XBT_DEBUG("Set up a new address: %zu, '%s'", i, addrs[i].c_str());
- /* Add it to the command line args */
- stream << addrs[i] << ' ';
- }
- std::string cmd = stream.str();
-
- /* size (in char) of pointers on this arch */
- int addr_len = addrs[0].size();
-
- XBT_VERB("Fire a first command: '%s'", cmd.c_str());
- FILE* pipe = popen(cmd.c_str(), "r");
- xbt_assert(pipe, "Cannot fork addr2line to display the backtrace");
-
- /* To read the output of addr2line */
- char line_func[1024];
- char line_pos[1024];
- for (std::size_t i = 0; i < count; i++) {
- XBT_DEBUG("Looking for symbol %zu, addr = '%s'", i, addrs[i].c_str());
- if (fgets(line_func, 1024, pipe)) {
- line_func[strlen(line_func) - 1] = '\0';
- } else {
- XBT_VERB("Cannot run fgets to look for symbol %zu, addr %s", i, addrs[i].c_str());
- strncpy(line_func, "???", 4);
- }
- if (fgets(line_pos, 1024, pipe)) {
- line_pos[strlen(line_pos) - 1] = '\0';
- } else {
- XBT_VERB("Cannot run fgets to look for symbol %zu, addr %s", i, addrs[i].c_str());
- strncpy(line_pos, backtrace_syms[i], 1024);
- }
-
- if (strcmp("??", line_func) != 0) {
- auto name = simgrid::xbt::demangle(line_func);
- XBT_DEBUG("Found static symbol %s at %s", name.get(), line_pos);
- result.push_back(simgrid::xbt::string_printf("%s at %s, %p", name.get(), line_pos, loc[i]));
- } else {
- /* Damn. The symbol is in a dynamic library. Let's get wild */
-
- unsigned long int offset = 0;
- int found = 0;
-
- /* let's look for the offset of this library in our addressing space */
- std::string maps_name = std::string("/proc/") + std::to_string(getpid()) + "/maps";
- std::ifstream maps(maps_name);
- if (not maps) {
- XBT_CRITICAL("open(\"%s\") failed: %s", maps_name.c_str(), strerror(errno));
- continue;
- }
- size_t pos;
- unsigned long int addr = std::stoul(addrs[i], &pos, 16);
- if (pos != addrs[i].length()) {
- XBT_CRITICAL("Cannot parse backtrace address '%s' (addr=%#lx)", addrs[i].c_str(), addr);
- }
- XBT_DEBUG("addr=%s (as string) =%#lx (as number)", addrs[i].c_str(), addr);
-
- while (not found) {
- unsigned long int first;
- unsigned long int last;
-
- std::string maps_buff;
- if (not std::getline(maps, maps_buff))
- break;
- if (i == 0) {
- XBT_DEBUG("map line: %s", maps_buff.c_str());
- }
- first = std::stoul(maps_buff, &pos, 16);
- maps_buff.erase(0, pos + 1);
- last = std::stoul(maps_buff, nullptr, 16);
- if (first < addr && addr < last) {
- offset = first;
- found = 1;
- }
- if (found) {
- XBT_DEBUG("%#lx in [%#lx-%#lx]", addr, first, last);
- XBT_DEBUG("Symbol found, map lines not further displayed (even if looking for next ones)");
- }
- }
- maps.close();
- addrs[i].clear();
-
- if (not found) {
- XBT_VERB("Problem while reading the maps file. Following backtrace will be mangled.");
- XBT_DEBUG("No dynamic. Static symbol: %s", backtrace_syms[i]);
- result.push_back(simgrid::xbt::string_printf("?? (%s)", backtrace_syms[i]));
- continue;
- }
-
- /* Ok, Found the offset of the maps line containing the searched symbol.
- We now need to substract this from the address we got from backtrace.
- */
-
- addrs[i] = simgrid::xbt::string_printf("0x%0*lx", addr_len - 2, addr - offset);
- XBT_DEBUG("offset=%#lx new addr=%s", offset, addrs[i].c_str());
-
- /* Got it. We have our new address. Let's get the library path and we are set */
- std::string p(backtrace_syms[i]);
- if (p[0] == '[') {
- /* library path not displayed in the map file either... */
- snprintf(line_func, 3, "??");
- } else {
- size_t p2 = p.find_first_of("( ");
- if (p2 != std::string::npos)
- p.erase(p2);
-
- /* Here we go, fire an addr2line up */
- std::string subcmd = std::string(ADDR2LINE) + " -f -e " + p + " " + addrs[i];
- XBT_VERB("Fire another command: '%s'", subcmd.c_str());
- FILE* subpipe = popen(subcmd.c_str(), "r");
- if (not subpipe) {
- xbt_die("Cannot fork addr2line to display the backtrace");
- }
- if (fgets(line_func, 1024, subpipe)) {
- line_func[strlen(line_func) - 1] = '\0';
- } else {
- XBT_VERB("Cannot read result of subcommand %s", subcmd.c_str());
- strncpy(line_func, "???", 4);
- }
- if (fgets(line_pos, 1024, subpipe)) {
- line_pos[strlen(line_pos) - 1] = '\0';
- } else {
- XBT_VERB("Cannot read result of subcommand %s", subcmd.c_str());
- strncpy(line_pos, backtrace_syms[i], 1024);
- }
- pclose(subpipe);
- }
-
- /* check whether the trick worked */
- if (strcmp("??", line_func)) {
- auto name = simgrid::xbt::demangle(line_func);
- XBT_DEBUG("Found dynamic symbol %s at %s", name.get(), line_pos);
- result.push_back(simgrid::xbt::string_printf("%s at %s, %p", name.get(), line_pos, loc[i]));
- } else {
- /* damn, nothing to do here. Let's print the raw address */
- XBT_DEBUG("Dynamic symbol not found. Raw address = %s", backtrace_syms[i]);
- result.push_back(simgrid::xbt::string_printf("?? at %s", backtrace_syms[i]));
- }
- }
- addrs[i].clear();
-
- /* Mask the bottom of the stack */
- const char* const breakers[] = {
- "main",
- "_ZN7simgrid6kernel7context13ThreadContext7wrapperE", // simgrid::kernel::context::ThreadContext::wrapper
- "_ZN7simgrid6kernel7context8UContext7wrapperE" // simgrid::kernel::context::UContext::wrapper
- };
- bool do_break = false;
- for (const char* b : breakers) {
- if (strncmp(b, line_func, strlen(b)) == 0) {
- do_break = true;
- break;
- }
- }
- if (do_break)
- break;