static inline bool IsDynamicSectionPointer()

in runtime/elf_utils.h [78:168]
86 lines of code
59 McCabe index (conditional complexity)

static inline bool IsDynamicSectionPointer(Elf32_Word d_tag, Elf32_Word e_machine) {
  switch (d_tag) {
    // case 1: well known d_tag values that imply Elf32_Dyn.d_un contains an address in d_ptr
    case DT_PLTGOT:
    case DT_HASH:
    case DT_STRTAB:
    case DT_SYMTAB:
    case DT_RELA:
    case DT_INIT:
    case DT_FINI:
    case DT_REL:
    case DT_DEBUG:
    case DT_JMPREL: {
      return true;
    }
    // d_val or ignored values
    case DT_NULL:
    case DT_NEEDED:
    case DT_PLTRELSZ:
    case DT_RELASZ:
    case DT_RELAENT:
    case DT_STRSZ:
    case DT_SYMENT:
    case DT_SONAME:
    case DT_RPATH:
    case DT_SYMBOLIC:
    case DT_RELSZ:
    case DT_RELENT:
    case DT_PLTREL:
    case DT_TEXTREL:
    case DT_BIND_NOW:
    case DT_INIT_ARRAYSZ:
    case DT_FINI_ARRAYSZ:
    case DT_RUNPATH:
    case DT_FLAGS: {
      return false;
    }
    // boundary values that should not be used
    case DT_ENCODING:
    case DT_LOOS:
    case DT_HIOS:
    case DT_LOPROC:
    case DT_HIPROC: {
      LOG(FATAL) << "Illegal d_tag value 0x" << std::hex << d_tag;
      return false;
    }
    default: {
      // case 2: "regular" DT_* ranges where even d_tag values imply an address in d_ptr
      if ((DT_ENCODING  < d_tag && d_tag < DT_LOOS)
          || (DT_LOOS   < d_tag && d_tag < DT_HIOS)
          || (DT_LOPROC < d_tag && d_tag < DT_HIPROC)) {
        // Special case for MIPS which breaks the regular rules between DT_LOPROC and DT_HIPROC
        if (e_machine == EM_MIPS) {
          switch (d_tag) {
            case DT_MIPS_RLD_VERSION:
            case DT_MIPS_TIME_STAMP:
            case DT_MIPS_ICHECKSUM:
            case DT_MIPS_IVERSION:
            case DT_MIPS_FLAGS:
            case DT_MIPS_LOCAL_GOTNO:
            case DT_MIPS_CONFLICTNO:
            case DT_MIPS_LIBLISTNO:
            case DT_MIPS_SYMTABNO:
            case DT_MIPS_UNREFEXTNO:
            case DT_MIPS_GOTSYM:
            case DT_MIPS_HIPAGENO: {
              return false;
            }
            case DT_MIPS_BASE_ADDRESS:
            case DT_MIPS_CONFLICT:
            case DT_MIPS_LIBLIST:
            case DT_MIPS_RLD_MAP: {
              return true;
            }
            default: {
              LOG(FATAL) << "Unknown MIPS d_tag value 0x" << std::hex << d_tag;
              return false;
            }
          }
        } else if ((d_tag % 2) == 0) {
          return true;
        } else {
          return false;
        }
      } else {
        LOG(FATAL) << "Unknown d_tag value 0x" << std::hex << d_tag;
        return false;
      }
    }
  }
}