File cdemangle.h

File List > code_source > templat > include > TempLat > util > debug > cdemangle.h

Go to the documentation of this file

#ifndef TEMPLAT_UTIL_DEBUG_CDEMANGLE_H
#define TEMPLAT_UTIL_DEBUG_CDEMANGLE_H

/* This file is part of TempLat, available at https://cosmolattice.github.io/templat .
   Copyright 2021-2026 The TempLat authors, see AUTHORS.md.
   Released under the MIT license, see LICENSE.md. */

// File info: Main contributor(s): Wessel Valkenburg, Year: 2019

#include <cxxabi.h>
#include <iostream>

namespace TempLat
{
  inline void CDemangle(std::ostream &stream, char *start)
  {
    // allocate string which will be filled with the demangled function name
    size_t funcnamesize = 4096;
    char *funcname = (char *)malloc(funcnamesize);

    char *begin_name = nullptr, *begin_offset = nullptr, *end_offset = nullptr;

#ifdef __APPLE__
    // OSX style stack trace
    for (char *p = start; *p; ++p) {
      if (p - 1 < start) continue; 
      if ((*p == '_') && (*(p - 1) == ' ')) {
        begin_name = p - 1;
      } else if (*p == '+') {
        begin_offset = p - 1;
        *begin_offset = '\0';
        if (std::string(p).length() > 2) begin_offset += 2;
      }
    }

    end_offset = begin_offset + std::string(begin_offset).length();

#else // other POSIXes
      // find parentheses and +address offset surrounding the mangled name:
      // ./module(function+0x15c) [0x8048a6d]
    for (char *p = start; *p; ++p) {
      if (*p == '(')
        begin_name = p;
      else if (*p == '+')
        begin_offset = p;
      else if (*p == ')' && begin_offset) {
        end_offset = p;
        break;
      }
    }
#endif
    if (begin_name && begin_offset && end_offset && begin_name < begin_offset) {
      *begin_name++ = '\0';
      *begin_offset++ = '\0';
      *end_offset = '\0';

      // mangled name is now in [begin_name, begin_offset) and caller
      // offset in [begin_offset, end_offset). now apply
      // __cxa_demangle():

      int status;
      char *ret = abi::__cxa_demangle(begin_name, funcname, &funcnamesize, &status);
      if (status == 0) {
        funcname = ret; // use possibly realloc()-ed string
        stream << "  " << start << " : " << funcname << " + " << begin_offset << "\n";
      } else {
        // demangling failed. Output function name as a C function with
        // no arguments.
        stream << "  " << start << " : " << begin_name << " + " << begin_offset << " ["
               << (status == -1 ? "alloc fail" : (status == -2 ? "invalid mangled name" : "invalid argument")) << "]\n";
      }
    } else {
      // couldn't parse the line? print the whole line.
      stream << start << "  %s (unparsed)\n";
    }
    free(funcname);
  }
} // namespace TempLat

#endif