Examples of errors detected by the V1001 diagnostic

V1001. Variable is assigned but not used by the end of the function.

EFL Core Libraries

V1001 The 'address_shadow' variable is assigned but is not used until the end of the function. elocation.c 1122

static Elocation_Address *address = NULL;

EAPI Eina_Bool
elocation_address_get(Elocation_Address *address_shadow)
{
   if (!address) return EINA_FALSE;
   if (address == address_shadow) return EINA_TRUE;

   address_shadow = address;
   return EINA_TRUE;
}

Most likely this is what should be written here: *address_shadow = *address;

Similar errors can be found in some other places:

• V1001 The 'screen' variable is assigned but is not used until the end of the function. ecore_x_xinerama.c 92
• V1001 The 'ret' variable is assigned but is not used until the end of the function. edje_edit.c 12774
• V1001 The 'ret' variable is assigned but is not used until the end of the function. edje_edit.c 15884
• And 2 additional diagnostic messages.

MuseScore

V1001 The 'ontime' variable is assigned but is not used until the end of the function. rendermidi.cpp 1176

bool renderNoteArticulation(....)
{
  int ontime    = 0;
  ....
  // render the suffix
  for (int j = 0; j < s; j++)
    ontime = makeEvent(suffix[j], ontime, tieForward(j,suffix));
  // render graceNotesAfter
  ontime = graceExtend(note->pitch(), ...., ontime);
  return true;
}

Skia Graphics Engine

V1001 CWE-563 The 'allDone' variable is assigned but is not used until the end of the function. skopcontour.cpp 40

SkOpSpan* SkOpContour::undoneSpan() {
  SkOpSegment* testSegment = &fHead;
  bool allDone = true;
  do {
    if (testSegment->done()) {
      continue;
    }
    allDone = false;
    return testSegment->undoneSpan();
  } while ((testSegment = testSegment->next()));
  if (allDone) {
    fDone = true;
  }
  return nullptr;
}

Very suspicious code, but it is difficult for me to understand what is the actual error here.

XNU kernel

V1001 CWE-563 The 'a' variable is assigned but is not used until the end of the function. sha1mod.c 120

__private_extern__ void
YSHA1Transform(u_int32_t state[5],
               const unsigned char buffer[64])
{
  u_int32_t a, b, c, d, e;
  ....
  state[0] += a;
  state[1] += b;
  state[2] += c;
  state[3] += d;
  state[4] += e;
  /* Wipe variables */
  a = b = c = d = e = 0;
}

The compiler can delete code "a = b = c = d = e = 0;" in terms of optimization.

Android

V1001 CWE-563 The 'a' variable is assigned but is not used until the end of the function. sha1.c 213

void SHA1Transform(uint32_t state[5], const uint8_t buffer[64])
{
  uint32_t a, b, c, d, e;
  ....
  /* Wipe variables */
  a = b = c = d = e = 0;
}

LibreOffice

V1001 The 'DL' variable is assigned but is not used by the end of the function. cipher.cxx 811

static void BF_updateECB(
    CipherContextBF    *ctx,
    rtlCipherDirection  direction,
    const sal_uInt8    *pData,
    sal_uInt8          *pBuffer,
    sal_Size            nLength)
{
    CipherKeyBF *key;
    sal_uInt32   DL, DR;

    key = &(ctx->m_key);
    if (direction == rtl_Cipher_DirectionEncode)
    {
        RTL_CIPHER_NTOHL64(pData, DL, DR, nLength);

        BF_encode(key, &DL, &DR);

        RTL_CIPHER_HTONL(DL, pBuffer);
        RTL_CIPHER_HTONL(DR, pBuffer);
    }
    else
    {
        RTL_CIPHER_NTOHL(pData, DL);
        RTL_CIPHER_NTOHL(pData, DR);

        BF_decode(key, &DL, &DR);

        RTL_CIPHER_HTONL64(DL, DR, pBuffer, nLength);
    }
    DL = DR = 0;
}

Similar errors can be found in some other places:

• V1001 The 'DL' variable is assigned but is not used by the end of the function. cipher.cxx 860

LLVM/Clang

V1001 [CWE-563] The 'Mode' variable is assigned but is not used by the end of the function. SIModeRegister.cpp 48

struct Status {
  unsigned Mask;
  unsigned Mode;

  Status() : Mask(0), Mode(0){};

  Status(unsigned Mask, unsigned Mode) : Mask(Mask), Mode(Mode) {
    Mode &= Mask;
  };
  ....
};

LLVM/Clang

V1001 [CWE-563] The 'Size' variable is assigned but is not used by the end of the function. Object.cpp 424

class SectionBase {
  ....
  uint64_t Size = 0;
  ....
};

class SymbolTableSection : public SectionBase {
  ....
};

void SymbolTableSection::addSymbol(Twine Name, uint8_t Bind, uint8_t Type,
                                   SectionBase *DefinedIn, uint64_t Value,
                                   uint8_t Visibility, uint16_t Shndx,
                                   uint64_t Size) {
  ....
  Sym.Value = Value;
  Sym.Visibility = Visibility;
  Sym.Size = Size;
  Sym.Index = Symbols.size();
  Symbols.emplace_back(llvm::make_unique<Symbol>(Sym));
  Size += this->EntrySize;
}

TON

V1001 The 'tmp_info' variable is assigned but is not used by the end of the function. analyzer.cpp 140

bool Op::set_var_info_except(const VarDescrList& new_var_info,
                        const std::vector<var_idx_t>& var_list) {
  if (!var_list.size()) {
    return set_var_info(new_var_info);
  }
  VarDescrList tmp_info{new_var_info};
  tmp_info -= var_list;
  return set_var_info(new_var_info);     // <=
}

Zephyr

V1001 The 'len' variable is assigned but is not used by the end of the function. lwm2m_rw_oma_tlv.c 338

static size_t put_end_tlv(struct lwm2m_output_context *out, u16_t mark_pos,
        u8_t *writer_flags, u8_t writer_flag,
        int tlv_type, int tlv_id)
{
  struct tlv_out_formatter_data *fd;
  struct oma_tlv tlv;
  u32_t len = 0U;

  fd = engine_get_out_user_data(out);
  if (!fd) {
    return 0;
  }

  *writer_flags &= ~writer_flag;

  len = out->out_cpkt->offset - mark_pos;

  /* use stored location */
  fd->mark_pos = mark_pos;

  /* set instance length */
  tlv_setup(&tlv, tlv_type, tlv_id, len);
  len = oma_tlv_put(&tlv, out, NULL, true) - tlv.length;

  return 0;
}

Universal

V1001 The 'scaledVector' variable is assigned but is not used by the end of the function. vector.hpp 124

template<typename Scalar>
vector<Scalar> operator*(double scalar, const vector<Scalar>& v) {
  vector<Scalar> scaledVector(v);
  scaledVector *= scalar;
  return v;
}

Similar errors can be found in some other places:

• V1001 The 'normalizedVector' variable is assigned but is not used by the end of the function. vector.hpp 131

LLVM/Clang

V1001 The 'T' variable is assigned but is not used by the end of the function. CommonArgs.cpp 87

const char *tools::SplitDebugName(const ArgList &Args, const InputInfo &Input,
                                  const InputInfo &Output) {
  if (Arg *A = Args.getLastArg(options::OPT_gsplit_dwarf_EQ))
    if (StringRef(A->getValue()) == "single")
      return Args.MakeArgString(Output.getFilename());

  Arg *FinalOutput = Args.getLastArg(options::OPT_o);
  if (FinalOutput && Args.hasArg(options::OPT_c)) {
    SmallString<128> T(FinalOutput->getValue());
    llvm::sys::path::replace_extension(T, "dwo");
    return Args.MakeArgString(T);
  } else {
    // Use the compilation dir.
    SmallString<128> T(
        Args.getLastArgValue(options::OPT_fdebug_compilation_dir));
    SmallString<128> F(llvm::sys::path::stem(Input.getBaseInput()));
    llvm::sys::path::replace_extension(F, "dwo");
    T += F;
    return Args.MakeArgString(F);       // <=
  }
}

Snort

V1001 The 'ptr' variable is assigned but is not used by the end of the function. spp_sfportscan.c 596

static int PortscanAlertTcp(PS_PROTO *proto, ....)
{
  ....
  int portsweep = 0;

  if (!proto)
    return -1;

  switch (proto->alerts)
  {
  case PS_ALERT_ONE_TO_ONE:
    ....
    break;

  case PS_ALERT_ONE_TO_ONE_DECOY:
    ....
    break;

  case PS_ALERT_PORTSWEEP:
    ....
    portsweep = 1;
    break;

  case PS_ALERT_DISTRIBUTED:
    ....
    break;

  case PS_ALERT_ONE_TO_ONE_FILTERED:
    ....
    break;

  case PS_ALERT_ONE_TO_ONE_DECOY_FILTERED:
    ....
    break;

  case PS_ALERT_PORTSWEEP_FILTERED:
    ....
    portsweep = 1;
    return 0;

  case PS_ALERT_DISTRIBUTED_FILTERED:
    ....
    break;

  default:
    return 0;
  }