-/* Copyright (c) 2005-2016. The SimGrid Team. All rights reserved. */
+/* Copyright (c) 2005-2018. The SimGrid Team. All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
+#include "src/internal_config.h"
+
#include <cstddef>
#include <cstdlib>
-
+#include <cstring>
+#include <fstream>
+#include <sstream>
+#include <sys/stat.h>
#include <vector>
-// Try to detect and use the C++ intanium ABI for name demangling:
+#include <boost/algorithm/string.hpp>
+
+// Try to detect and use the C++ itanium ABI for name demangling:
#ifdef __GXX_ABI_VERSION
#include <cxxabi.h>
#endif
+#if HAVE_EXECINFO_H
+#include <execinfo.h>
+#endif
#include "simgrid/simix.h" /* SIMIX_process_self_get_name() */
-#include <xbt/backtrace.h>
#include <xbt/backtrace.hpp>
#include <xbt/log.h>
+#include <xbt/string.hpp>
#include <xbt/sysdep.h>
-#include "src/internal_config.h"
-
-extern "C" {
-
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_backtrace, xbt, "Backtrace");
+static bool startWith(std::string str, const char* prefix)
+{
+ return strncmp(str.c_str(), prefix, strlen(prefix)) == 0;
}
void xbt_backtrace_display(xbt_backtrace_location_t* loc, std::size_t count)
{
-#ifdef HAVE_BACKTRACE
- std::vector<std::string> backtrace = simgrid::xbt::resolveBacktrace(loc, count);
+ std::vector<std::string> backtrace = simgrid::xbt::resolve_backtrace(loc, count);
if (backtrace.empty()) {
- fprintf(stderr, "(backtrace not set)\n");
+ fprintf(stderr, "(backtrace not set -- maybe unavailable on this architecture?)\n");
return;
}
fprintf(stderr, "Backtrace (displayed in process %s):\n", SIMIX_process_self_get_name());
- for (std::string const& s : backtrace)
- fprintf(stderr, "---> %s\n", s.c_str());
-#else
- XBT_ERROR("Cannot display backtrace when compiled without libunwind.");
-#endif
+ for (std::string const& s : backtrace) {
+ if (startWith(s, "xbt_backtrace_display_current"))
+ continue;
+
+ std::fprintf(stderr, "---> '%s'\n", s.c_str());
+ if (startWith(s, "SIMIX_simcall_handle") ||
+ startWith(s, "simgrid::xbt::MainFunction") /* main used with thread factory */)
+ break;
+ }
}
/** @brief show the backtrace of the current point (lovely while debugging) */
return std::unique_ptr<char, void(*)(void*)>(xbt_strdup(name), std::free);
}
-std::vector<xbt_backtrace_location_t> backtrace()
+Backtrace backtrace()
{
const std::size_t size = 10;
xbt_backtrace_location_t loc[size];
size_t used = xbt_backtrace_current(loc, size);
- return std::vector<xbt_backtrace_location_t>(loc, loc + used);
+ return Backtrace(loc, loc + used);
}
}
}
-#if HAVE_BACKTRACE && HAVE_EXECINFO_H && HAVE_POPEN && defined(ADDR2LINE)
-# include "src/xbt/backtrace_linux.cpp"
-#else
-# include "src/xbt/backtrace_dummy.cpp"
+size_t xbt_backtrace_current(xbt_backtrace_location_t* loc, std::size_t count)
+{
+ std::size_t used = 0;
+#if HAVE_BACKTRACE
+ used = backtrace(loc, count);
+ if (used == 0) {
+ std::fprintf(stderr, "The backtrace() function failed, which probably means that the memory is exhausted\n.");
+ std::fprintf(stderr, "Bailing out now since there is nothing I can do without a decent amount of memory\n.");
+ std::fprintf(stderr, "Please go fix the memleaks\n");
+ std::exit(1);
+ }
#endif
+ return used;
+}
+
+namespace simgrid {
+namespace xbt {
+
+/** Find the path of the binary file from the name found in argv */
+static std::string get_binary_path()
+{
+ struct stat stat_buf;
+
+ if (xbt_binary_name == nullptr)
+ return "";
+
+ // We found it, we are happy:
+ if (stat(xbt_binary_name, &stat_buf) == 0)
+ return xbt_binary_name;
+
+ // Not found, look in the PATH:
+ char* path = getenv("PATH");
+ if (path == nullptr)
+ return "";
+
+ XBT_DEBUG("Looking in the PATH: %s\n", path);
+ std::vector<std::string> path_list;
+ boost::split(path_list, path, boost::is_any_of(":;"));
+
+ for (std::string const& path_item : path_list) {
+ std::string binary_name = simgrid::xbt::string_printf("%s/%s", path_item.c_str(), xbt_binary_name);
+ bool found = (stat(binary_name.c_str(), &stat_buf) == 0);
+ XBT_DEBUG("Looked in the PATH for the binary. %s %s", found ? "Found" : "Not found", binary_name.c_str());
+ if (found)
+ return binary_name;
+ }
+
+ // Not found at all:
+ return "";
+}
+
+std::vector<std::string> resolve_backtrace(xbt_backtrace_location_t const* loc, std::size_t count)
+{
+ std::vector<std::string> result;
+
+#if HAVE_BACKTRACE && HAVE_EXECINFO_H && HAVE_POPEN && defined(ADDR2LINE)
+ // FIXME: This code could be greatly improved/simplified with
+ // http://cairo.sourcearchive.com/documentation/1.9.4/backtrace-symbols_8c-source.html
+ 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;
+ }
+ pclose(pipe);
+ xbt_free(backtrace_syms);
+#endif /* ADDR2LINE usable to resolve the backtrace */
+ return result;
+}
+
+} // namespace xbt
+} // namespace simgrid
