Function RemoveRPathELF

Source/cmSystemTools.cxx:3927–4080

}

static cm::optional<bool> RemoveRPathELF(std::string const& file,
                                         std::string* emsg, bool* removed)
{
  if (removed) {
    *removed = false;
  }
  int zeroCount = 0;
  unsigned long zeroPosition[2] = { 0, 0 };
  unsigned long zeroSize[2] = { 0, 0 };
  unsigned long bytesBegin = 0;
  std::vector<char> bytes;
  {
    // Parse the ELF binary.
    cmELF elf(file.c_str());
    if (!elf) {
      return cm::nullopt; // Not a valid ELF file.
    }

    // Get the RPATH and RUNPATH entries from it and sort them by index
    // in the dynamic section header.
    int se_count = 0;
    cmELF::StringEntry const* se[2] = { nullptr, nullptr };
    if (cmELF::StringEntry const* se_rpath = elf.GetRPath()) {
      se[se_count++] = se_rpath;
    }
    if (cmELF::StringEntry const* se_runpath = elf.GetRunPath()) {
      se[se_count++] = se_runpath;
    }
    if (se_count == 0) {
      // There is no RPATH or RUNPATH anyway.
      return true;
    }
    if (se_count == 2 && se[1]->IndexInSection < se[0]->IndexInSection) {
      std::swap(se[0], se[1]);
    }

    // Obtain a copy of the dynamic entries
    cmELF::DynamicEntryList dentries = elf.GetDynamicEntries();
    if (dentries.empty()) {
      // This should happen only for invalid ELF files where a DT_NULL
      // appears before the end of the table.
      if (emsg) {
        *emsg = "DYNAMIC section contains a DT_NULL before the end.";
      }
      return false;
    }

    // Save information about the string entries to be zeroed.
    zeroCount = se_count;
    for (int i = 0; i < se_count; ++i) {
      zeroPosition[i] = se[i]->Position;
      zeroSize[i] = se[i]->Size;
    }

    // Get size of one DYNAMIC entry
    unsigned long const sizeof_dentry =
      elf.GetDynamicEntryPosition(1) - elf.GetDynamicEntryPosition(0);