/** @file

 Utility functions for expression evaluation.

 Copyright (c) 2011-2019, Intel Corporation. All rights reserved.<BR>
 SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include "IfrParse.h"

#define gEmptyString L""
//
// Global stack used to evaluate boolean expresions
//
EFI_HII_VALUE *mOpCodeScopeStack = NULL;
EFI_HII_VALUE *mOpCodeScopeStackEnd = NULL;
EFI_HII_VALUE *mOpCodeScopeStackPointer = NULL;

EFI_HII_VALUE *mExpressionEvaluationStack = NULL;
EFI_HII_VALUE *mExpressionEvaluationStackEnd = NULL;
EFI_HII_VALUE *mExpressionEvaluationStackPointer = NULL;
UINTN         mExpressionEvaluationStackOffset = 0;

EFI_HII_VALUE *mCurrentExpressionStack = NULL;
EFI_HII_VALUE *mCurrentExpressionEnd = NULL;
EFI_HII_VALUE *mCurrentExpressionPointer = NULL;

EFI_HII_VALUE *mMapExpressionListStack = NULL;
EFI_HII_VALUE *mMapExpressionListEnd = NULL;
EFI_HII_VALUE *mMapExpressionListPointer = NULL;

/**
  Get Value for given Name from a NameValue Storage.

  @param  Storage                The NameValue Storage.
  @param  Name                   The Name.
  @param  Value                  The retured Value.

  @retval EFI_SUCCESS            Value found for given Name.
  @retval EFI_NOT_FOUND          No such Name found in NameValue storage.

**/
EFI_STATUS
GetValueByName (
  IN FORMSET_STORAGE         *Storage,
  IN CHAR16                  *Name,
  IN OUT CHAR16              **Value
  )
{
  LIST_ENTRY              *Link;
  NAME_VALUE_NODE         *Node;

  *Value = NULL;

  Link = GetFirstNode (&Storage->NameValueListHead);
  while (!IsNull (&Storage->NameValueListHead, Link)) {
    Node = NAME_VALUE_NODE_FROM_LINK (Link);

    if (FceStrCmp (Name, Node->Name) == 0) {
      NewStringCpy (Value, Node->EditValue);
      return EFI_SUCCESS;
    }

    Link = GetNextNode (&Storage->NameValueListHead, Link);
  }

  return EFI_NOT_FOUND;
}

/**
  Grow size of the stack.

  This is an internal function.

  @param  Stack                  On input: old stack; On output: new stack
  @param  StackPtr               On input: old stack pointer; On output: new stack
                                 pointer
  @param  StackEnd               On input: old stack end; On output: new stack end

  @retval EFI_SUCCESS            Grow stack success.
  @retval EFI_OUT_OF_RESOURCES   No enough memory for stack space.

**/
EFI_STATUS
GrowStack (
  IN OUT EFI_HII_VALUE  **Stack,
  IN OUT EFI_HII_VALUE  **StackPtr,
  IN OUT EFI_HII_VALUE  **StackEnd
  )
{
  UINTN           Size;
  EFI_HII_VALUE  *NewStack;

  Size = EXPRESSION_STACK_SIZE_INCREMENT;
  if (*StackPtr != NULL) {
    Size = Size + (*StackEnd - *Stack);
  }

  NewStack = AllocatePool (Size * sizeof (EFI_HII_VALUE));
  if (NewStack == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  if (*StackPtr != NULL) {
    //
    // Copy from Old Stack to the New Stack
    //
    CopyMem (
      NewStack,
      *Stack,
      (*StackEnd - *Stack) * sizeof (EFI_HII_VALUE)
      );

    //
    // Free The Old Stack
    //
    FreePool (*Stack);
  }

  //
  // Make the Stack pointer point to the old data in the new stack
  //
  *StackPtr = NewStack + (*StackPtr - *Stack);
  *Stack    = NewStack;
  *StackEnd = NewStack + Size;

  return EFI_SUCCESS;
}


/**
  Push an element onto the Boolean Stack.

  @param  Stack                  On input: old stack; On output: new stack
  @param  StackPtr               On input: old stack pointer; On output: new stack
                                 pointer
  @param  StackEnd               On input: old stack end; On output: new stack end
  @param  Data                   Data to push.

  @retval EFI_SUCCESS            Push stack success.

**/
EFI_STATUS
PushStack (
  IN OUT EFI_HII_VALUE       **Stack,
  IN OUT EFI_HII_VALUE       **StackPtr,
  IN OUT EFI_HII_VALUE       **StackEnd,
  IN EFI_HII_VALUE           *Data
  )
{
  EFI_STATUS  Status;

  //
  // Check for a stack overflow condition
  //
  if (*StackPtr >= *StackEnd) {
    //
    // Grow the stack
    //
    Status = GrowStack (Stack, StackPtr, StackEnd);
    if (EFI_ERROR (Status)) {
      return Status;
    }
  }

  //
  // Push the item onto the stack
  //
  CopyMem (*StackPtr, Data, sizeof (EFI_HII_VALUE));
  *StackPtr = *StackPtr + 1;

  return EFI_SUCCESS;
}


/**
  Pop an element from the stack.

  @param  Stack                  On input: old stack
  @param  StackPtr               On input: old stack pointer; On output: new stack pointer
  @param  Data                   Data to pop.

  @retval EFI_SUCCESS            The value was popped onto the stack.
  @retval EFI_ACCESS_DENIED      The pop operation underflowed the stack

**/
EFI_STATUS
PopStack (
  IN  EFI_HII_VALUE          *Stack,
  IN OUT EFI_HII_VALUE       **StackPtr,
  OUT EFI_HII_VALUE          *Data
  )
{
  //
  // Check for a stack underflow condition
  //
  if (*StackPtr == Stack) {
    return EFI_ACCESS_DENIED;
  }

  //
  // Pop the item off the stack
  //
  *StackPtr = *StackPtr - 1;
  CopyMem (Data, *StackPtr, sizeof (EFI_HII_VALUE));
  return EFI_SUCCESS;
}


/**
  Reset stack pointer to begin of the stack.

**/
VOID
ResetCurrentExpressionStack (
  VOID
  )
{
  mCurrentExpressionPointer = mCurrentExpressionStack;
}


/**
  Push current expression onto the Stack

  @param  Pointer                Pointer to current expression.

  @retval EFI_SUCCESS            The value was pushed onto the stack.
  @retval EFI_OUT_OF_RESOURCES   There is not enough system memory to grow the stack.

**/
EFI_STATUS
PushCurrentExpression (
  IN VOID  *Pointer
  )
{
  EFI_HII_VALUE  Data;

  Data.Type = EFI_IFR_TYPE_NUM_SIZE_64;
  Data.Value.u64 = (UINT64) (UINTN) Pointer;

  return PushStack (
    &mCurrentExpressionStack,
    &mCurrentExpressionPointer,
    &mCurrentExpressionEnd,
    &Data
    );
}


/**
  Pop current expression from the Stack

  @param  Pointer                Pointer to current expression to be pop.

  @retval EFI_SUCCESS            The value was pushed onto the stack.
  @retval EFI_OUT_OF_RESOURCES   There is not enough system memory to grow the stack.

**/
EFI_STATUS
PopCurrentExpression (
  OUT VOID    **Pointer
  )
{
  EFI_STATUS     Status;
  EFI_HII_VALUE  Data;

  Status = PopStack (
    mCurrentExpressionStack,
    &mCurrentExpressionPointer,
    &Data
    );

  *Pointer = (VOID *) (UINTN) Data.Value.u64;

  return Status;
}

/**
  Reset stack pointer to begin of the stack.

**/
VOID
ResetMapExpressionListStack (
  VOID
  )
{
  mMapExpressionListPointer = mMapExpressionListStack;
}


/**
  Push the list of map expression onto the Stack

  @param  Pointer                Pointer to the list of map expression to be pushed.

  @retval EFI_SUCCESS            The value was pushed onto the stack.
  @retval EFI_OUT_OF_RESOURCES   There is not enough system memory to grow the stack.

**/
EFI_STATUS
PushMapExpressionList (
  IN VOID  *Pointer
  )
{
  EFI_HII_VALUE  Data;

  Data.Type = EFI_IFR_TYPE_NUM_SIZE_64;
  Data.Value.u64 = (UINT64) (UINTN) Pointer;

  return PushStack (
    &mMapExpressionListStack,
    &mMapExpressionListPointer,
    &mMapExpressionListEnd,
    &Data
    );
}


/**
  Pop the list of map expression from the Stack

  @param  Pointer                Pointer to the list of map expression to be pop.

  @retval EFI_SUCCESS            The value was pushed onto the stack.
  @retval EFI_OUT_OF_RESOURCES   There is not enough system memory to grow the stack.

**/
EFI_STATUS
PopMapExpressionList (
  OUT VOID    **Pointer
  )
{
  EFI_STATUS     Status;
  EFI_HII_VALUE  Data;

  Status = PopStack (
    mMapExpressionListStack,
    &mMapExpressionListPointer,
    &Data
    );

  *Pointer = (VOID *) (UINTN) Data.Value.u64;

  return Status;
}

/**
  Reset stack pointer to begin of the stack.

**/
VOID
ResetScopeStack (
  VOID
  )
{
  mOpCodeScopeStackPointer = mOpCodeScopeStack;
}


/**
  Push an Operand onto the Stack

  @param  Operand                Operand to push.

  @retval EFI_SUCCESS            The value was pushed onto the stack.
  @retval EFI_OUT_OF_RESOURCES   There is not enough system memory to grow the
                                 stack.

**/
EFI_STATUS
PushScope (
  IN UINT8   Operand
  )
{
  EFI_HII_VALUE  Data;

  Data.Type = EFI_IFR_TYPE_NUM_SIZE_8;
  Data.Value.u8 = Operand;

  return PushStack (
           &mOpCodeScopeStack,
           &mOpCodeScopeStackPointer,
           &mOpCodeScopeStackEnd,
           &Data
           );
}


/**
  Pop an Operand from the Stack

  @param  Operand                Operand to pop.

  @retval EFI_SUCCESS            The value was pushed onto the stack.
  @retval EFI_OUT_OF_RESOURCES   There is not enough system memory to grow the
                                 stack.

**/
EFI_STATUS
PopScope (
  OUT UINT8     *Operand
  )
{
  EFI_STATUS     Status;
  EFI_HII_VALUE  Data;

  Status = PopStack (
             mOpCodeScopeStack,
             &mOpCodeScopeStackPointer,
             &Data
             );

  *Operand = Data.Value.u8;

  return Status;
}


/**
  Push an Expression value onto the Stack

  @param  Value                  Expression value to push.

  @retval EFI_SUCCESS            The value was pushed onto the stack.
  @retval EFI_OUT_OF_RESOURCES   There is not enough system memory to grow the
                                 stack.

**/
EFI_STATUS
PushExpression (
  IN EFI_HII_VALUE  *Value
  )
{
  return PushStack (
           &mExpressionEvaluationStack,
           &mExpressionEvaluationStackPointer,
           &mExpressionEvaluationStackEnd,
           Value
           );
}


/**
  Pop an Expression value from the stack.

  @param  Value                  Expression value to pop.

  @retval EFI_SUCCESS            The value was popped onto the stack.
  @retval EFI_ACCESS_DENIED      The pop operation underflowed the stack

**/
EFI_STATUS
PopExpression (
  OUT EFI_HII_VALUE  *Value
  )
{
  return PopStack (
           mExpressionEvaluationStack + mExpressionEvaluationStackOffset,
           &mExpressionEvaluationStackPointer,
           Value
           );
}

/**
  Get current stack offset from stack start.

  @return Stack offset to stack start.
**/
UINTN
SaveExpressionEvaluationStackOffset (
  )
{
  UINTN TempStackOffset;
  TempStackOffset = mExpressionEvaluationStackOffset;
  mExpressionEvaluationStackOffset = mExpressionEvaluationStackPointer - mExpressionEvaluationStack;
  return TempStackOffset;
}

/**
  Restore stack offset based on input stack offset

  @param  StackOffset  Offset to stack start.

**/
VOID
RestoreExpressionEvaluationStackOffset (
  UINTN StackOffset
  )
{
  mExpressionEvaluationStackOffset = StackOffset;
}


/**
  Search a Question in Form scope using its QuestionId.

  @param  Form                   The form which contains this Question.
  @param  QuestionId             Id of this Question.

  @retval Pointer                The Question.
  @retval NULL                   Specified Question not found in the form.

**/
FORM_BROWSER_STATEMENT *
IdToQuestion2 (
  IN FORM_BROWSER_FORM  *Form,
  IN UINT16             QuestionId
  )
{
  LIST_ENTRY              *Link;
  FORM_BROWSER_STATEMENT  *Question;

  if (QuestionId == 0) {
    //
    // The value of zero is reserved
    //
    return NULL;
  }

  Link = GetFirstNode (&Form->StatementListHead);
  while (!IsNull (&Form->StatementListHead, Link)) {
    Question = FORM_BROWSER_STATEMENT_FROM_LINK (Link);

    if (Question->QuestionId == QuestionId) {
      return Question;
    }

    Link = GetNextNode (&Form->StatementListHead, Link);
  }

  return NULL;
}


/**
  Search a Question in Formset scope using its QuestionId.

  @param  FormSet                The formset which contains this form.
  @param  Form                   The form which contains this Question.
  @param  QuestionId             Id of this Question.

  @retval Pointer                The Question.
  @retval NULL                   Specified Question not found in the form.

**/
FORM_BROWSER_STATEMENT *
IdToQuestion (
  IN FORM_BROWSER_FORMSET  *FormSet,
  IN FORM_BROWSER_FORM     *Form,
  IN UINT16                QuestionId
  )
{
  LIST_ENTRY              *Link;
  FORM_BROWSER_STATEMENT  *Question;

  //
  // Search in the form scope first
  //
  Question = IdToQuestion2 (Form, QuestionId);
  if (Question != NULL) {
    return Question;
  }

  //
  // Search in the formset scope
  //
  Link = GetFirstNode (&FormSet->FormListHead);
  while (!IsNull (&FormSet->FormListHead, Link)) {
    Form = FORM_BROWSER_FORM_FROM_LINK (Link);

    Question = IdToQuestion2 (Form, QuestionId);
    if (Question != NULL) {
      return Question;
    }

    Link = GetNextNode (&FormSet->FormListHead, Link);
  }

  return NULL;
}


/**
  Get Expression given its RuleId.

  @param  Form                   The form which contains this Expression.
  @param  RuleId                 Id of this Expression.

  @retval Pointer                The Expression.
  @retval NULL                   Specified Expression not found in the form.

**/
FORM_EXPRESSION *
RuleIdToExpression (
  IN FORM_BROWSER_FORM  *Form,
  IN UINT8              RuleId
  )
{
  LIST_ENTRY       *Link;
  FORM_EXPRESSION  *Expression;

  Link = GetFirstNode (&Form->ExpressionListHead);
  while (!IsNull (&Form->ExpressionListHead, Link)) {
    Expression = FORM_EXPRESSION_FROM_LINK (Link);

    if ((Expression->Type == EFI_HII_EXPRESSION_RULE) && (Expression->RuleId == RuleId)) {
      return Expression;
    }

    Link = GetNextNode (&Form->ExpressionListHead, Link);
  }

  return NULL;
}

/**
  Convert the input Unicode character to upper.

  @param String  Th Unicode character to be converted.

**/
VOID
IfrStrToUpper (
  IN CHAR16                   *String
  )
{
  while (*String != 0) {
    if ((*String >= 'a') && (*String <= 'z')) {
      *String = (UINT16) ((*String) & ((UINT16) ~0x20));
    }
    String++;
  }
}

/**
  Evaluate opcode EFI_IFR_TO_STRING.

  @param  FormSet                Formset which contains this opcode.
  @param  Format                 String format in EFI_IFR_TO_STRING.
  @param  Result                 Evaluation result for this opcode.

  @retval EFI_SUCCESS            Opcode evaluation success.
  @retval Other                  Opcode evaluation failed.

**/
EFI_STATUS
IfrToString (
  IN FORM_BROWSER_FORMSET  *FormSet,
  IN UINT8                 Format,
  OUT  EFI_HII_VALUE       *Result
  )
{
  EFI_STATUS     Status;
  EFI_HII_VALUE  Value;
  CHAR16         *PrintFormat;
  CHAR16         Buffer[MAXIMUM_VALUE_CHARACTERS];
  UINTN          BufferSize;

  Status = PopExpression (&Value);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  switch (Value.Type) {
  case EFI_IFR_TYPE_NUM_SIZE_8:
  case EFI_IFR_TYPE_NUM_SIZE_16:
  case EFI_IFR_TYPE_NUM_SIZE_32:
  case EFI_IFR_TYPE_NUM_SIZE_64:
    BufferSize = MAXIMUM_VALUE_CHARACTERS * sizeof (CHAR16);
    switch (Format) {
    case EFI_IFR_STRING_UNSIGNED_DEC:
    case EFI_IFR_STRING_SIGNED_DEC:
      PrintFormat = L"%ld";
      break;

    case EFI_IFR_STRING_LOWERCASE_HEX:
      PrintFormat = L"%lx";
      break;

    case EFI_IFR_STRING_UPPERCASE_HEX:
      PrintFormat = L"%lX";
      break;

    default:
      return EFI_UNSUPPORTED;
    }
    UnicodeSPrint (Buffer, BufferSize, PrintFormat, Value.Value.u64);
    break;

  case EFI_IFR_TYPE_STRING:
    CopyMem (Result, &Value, sizeof (EFI_HII_VALUE));
    return EFI_SUCCESS;

  case EFI_IFR_TYPE_BOOLEAN:
    break;

  default:
    return EFI_UNSUPPORTED;
  }

  Result->Type = EFI_IFR_TYPE_STRING;
  //Result->Value.string = NewString (String, FormSet->HiiHandle);
  return EFI_SUCCESS;
}

/**
  Evaluate opcode EFI_IFR_TO_UINT.

  @param  FormSet                Formset which contains this opcode.
  @param  Result                 Evaluation result for this opcode.

  @retval EFI_SUCCESS            Opcode evaluation success.
  @retval Other                  Opcode evaluation failed.

**/
EFI_STATUS
IfrToUint (
  IN FORM_BROWSER_FORMSET  *FormSet,
  OUT  EFI_HII_VALUE       *Result
  )
{
  EFI_STATUS     Status;
  EFI_HII_VALUE  Value;
  CHAR16         *String;
  CHAR16         *StringPtr;

  Status = PopExpression (&Value);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  if (Value.Type >= EFI_IFR_TYPE_OTHER) {
    return EFI_UNSUPPORTED;
  }

  Status = EFI_SUCCESS;
  if (Value.Type == EFI_IFR_TYPE_STRING) {
    String = GetToken (Value.Value.string, FormSet->UnicodeBinary);
    if (String == NULL) {
      return EFI_NOT_FOUND;
    }

    IfrStrToUpper (String);
    StringPtr = StrStr (String, L"0X");
    if (StringPtr != NULL) {
      //
      // Hex string
      //
      Result->Value.u64 = FceStrHexToUint64 (String);
    } else {
      //
      // decimal string
      //
      Result->Value.u64 = FceStrDecimalToUint64 (String);
    }
    FreePool (String);
  } else {
    CopyMem (Result, &Value, sizeof (EFI_HII_VALUE));
  }

  Result->Type = EFI_IFR_TYPE_NUM_SIZE_64;
  return Status;
}

/**
  Evaluate opcode EFI_IFR_CATENATE.

  @param  FormSet                Formset which contains this opcode.
  @param  Result                 Evaluation result for this opcode.

  @retval EFI_SUCCESS            Opcode evaluation success.
  @retval Other                  Opcode evaluation failed.

**/
EFI_STATUS
IfrCatenate (
  IN FORM_BROWSER_FORMSET  *FormSet,
  OUT  EFI_HII_VALUE       *Result
  )
{
  EFI_STATUS     Status;
  EFI_HII_VALUE  Value;
  CHAR16         *String[2];
  UINTN          Index;
  CHAR16         *StringPtr;
  UINTN          Size;

  //
  // String[0] - The second string
  // String[1] - The first string
  //
  String[0] = NULL;
  String[1] = NULL;
  StringPtr = NULL;
  Status = EFI_SUCCESS;

  for (Index = 0; Index < 2; Index++) {
    Status = PopExpression (&Value);
    if (EFI_ERROR (Status)) {
      goto Done;
    }

    if (Value.Type != EFI_IFR_TYPE_STRING) {
      Status = EFI_UNSUPPORTED;
      goto Done;
    }

    String[Index] = GetToken (Value.Value.string, FormSet->UnicodeBinary);
    if (String[Index] == NULL) {
      Status = EFI_NOT_FOUND;
      goto Done;
    }
  }

  Size = FceStrSize (String[0]);
  StringPtr= AllocatePool (FceStrSize (String[1]) + Size);
  ASSERT (StringPtr != NULL);
  StrCpy (StringPtr, String[1]);
  StrCat (StringPtr, String[0]);

  Result->Type = EFI_IFR_TYPE_STRING;
  //Result->Value.string = NewString (StringPtr, FormSet->HiiHandle);

Done:
  if (String[0] != NULL) {
    FreePool (String[0]);
  }
  if (String[1] != NULL) {
    FreePool (String[1]);
  }
  if (StringPtr != NULL) {
    FreePool (StringPtr);
  }

  return Status;
}

/**
  Evaluate opcode EFI_IFR_MATCH.

  @param  FormSet                Formset which contains this opcode.
  @param  Result                 Evaluation result for this opcode.

  @retval EFI_SUCCESS            Opcode evaluation success.
  @retval Other                  Opcode evaluation failed.

**/
EFI_STATUS
IfrMatch (
  IN FORM_BROWSER_FORMSET  *FormSet,
  OUT  EFI_HII_VALUE       *Result
  )
{
  EFI_STATUS     Status;
  EFI_HII_VALUE  Value;
  CHAR16         *String[2];
  UINTN          Index;

  //
  // String[0] - The string to search
  // String[1] - pattern
  //
  String[0] = NULL;
  String[1] = NULL;
  Status = EFI_SUCCESS;
  for (Index = 0; Index < 2; Index++) {
    Status = PopExpression (&Value);
    if (EFI_ERROR (Status)) {
      goto Done;
    }

    if (Value.Type != EFI_IFR_TYPE_STRING) {
      Status = EFI_UNSUPPORTED;
      goto Done;
    }

    String[Index] = GetToken (Value.Value.string, FormSet->UnicodeBinary);
    if (String [Index] == NULL) {
      Status = EFI_NOT_FOUND;
      goto Done;
    }
  }

  Result->Type = EFI_IFR_TYPE_BOOLEAN;
  Result->Value.b = MetaiMatch (String[0], String[1]);

Done:
  if (String[0] != NULL) {
    FreePool (String[0]);
  }
  if (String[1] != NULL) {
    FreePool (String[1]);
  }

  return Status;
}


/**
  Evaluate opcode EFI_IFR_FIND.

  @param  FormSet                Formset which contains this opcode.
  @param  Format                 Case sensitive or insensitive.
  @param  Result                 Evaluation result for this opcode.

  @retval EFI_SUCCESS            Opcode evaluation success.
  @retval Other                  Opcode evaluation failed.

**/
EFI_STATUS
IfrFind (
  IN FORM_BROWSER_FORMSET  *FormSet,
  IN UINT8                 Format,
  OUT  EFI_HII_VALUE       *Result
  )
{
  EFI_STATUS     Status;
  EFI_HII_VALUE  Value;
  CHAR16         *String[2];
  UINTN          Base;
  CHAR16         *StringPtr;
  UINTN          Index;

  if (Format > EFI_IFR_FF_CASE_INSENSITIVE) {
    return EFI_UNSUPPORTED;
  }

  Status = PopExpression (&Value);
  if (EFI_ERROR (Status)) {
    return Status;
  }
  if (Value.Type > EFI_IFR_TYPE_NUM_SIZE_64) {
    return EFI_UNSUPPORTED;
  }
  Base = (UINTN) Value.Value.u64;

  //
  // String[0] - sub-string
  // String[1] - The string to search
  //
  String[0] = NULL;
  String[1] = NULL;
  for (Index = 0; Index < 2; Index++) {
    Status = PopExpression (&Value);
    if (EFI_ERROR (Status)) {
      goto Done;
    }

    if (Value.Type != EFI_IFR_TYPE_STRING) {
      Status = EFI_UNSUPPORTED;
      goto Done;
    }

    String[Index] = GetToken (Value.Value.string, FormSet->UnicodeBinary);
    if (String[Index] == NULL) {
      Status = EFI_NOT_FOUND;
      goto Done;
    }

    if (Format == EFI_IFR_FF_CASE_INSENSITIVE) {
      //
      // Case insensitive, convert both string to upper case
      //
      IfrStrToUpper (String[Index]);
    }
  }

  Result->Type = EFI_IFR_TYPE_NUM_SIZE_64;
  if (Base >= FceStrLen (String[1])) {
    Result->Value.u64 = 0xFFFFFFFFFFFFFFFFULL;
  } else {
    StringPtr = StrStr (String[1] + Base, String[0]);
    Result->Value.u64 = (StringPtr == NULL) ? 0xFFFFFFFFFFFFFFFFULL : (StringPtr - String[1]);
  }

Done:
  if (String[0] != NULL) {
    FreePool (String[0]);
  }
  if (String[1] != NULL) {
    FreePool (String[1]);
  }

  return Status;
}


/**
  Evaluate opcode EFI_IFR_MID.

  @param  FormSet                Formset which contains this opcode.
  @param  Result                 Evaluation result for this opcode.

  @retval EFI_SUCCESS            Opcode evaluation success.
  @retval Other                  Opcode evaluation failed.

**/
EFI_STATUS
IfrMid (
  IN FORM_BROWSER_FORMSET  *FormSet,
  OUT  EFI_HII_VALUE       *Result
  )
{
  EFI_STATUS     Status;
  EFI_HII_VALUE  Value;
  CHAR16         *String;
  UINTN          Base;
  UINTN          Length;
  CHAR16         *SubString;

  Status = PopExpression (&Value);
  if (EFI_ERROR (Status)) {
    return Status;
  }
  if (Value.Type > EFI_IFR_TYPE_NUM_SIZE_64) {
    return EFI_UNSUPPORTED;
  }
  Length = (UINTN) Value.Value.u64;

  Status = PopExpression (&Value);
  if (EFI_ERROR (Status)) {
    return Status;
  }
  if (Value.Type > EFI_IFR_TYPE_NUM_SIZE_64) {
    return EFI_UNSUPPORTED;
  }
  Base = (UINTN) Value.Value.u64;

  Status = PopExpression (&Value);
  if (EFI_ERROR (Status)) {
    return Status;
  }
  if (Value.Type != EFI_IFR_TYPE_STRING) {
    return EFI_UNSUPPORTED;
  }
  String = GetToken (Value.Value.string, FormSet->UnicodeBinary);
  if (String == NULL) {
    return EFI_NOT_FOUND;
  }

  if ((Length == 0) || (Base >= FceStrLen (String))) {
    SubString = gEmptyString;
  } else {
    SubString = String + Base;
    if ((Base + Length) < FceStrLen (String)) {
      SubString[Length] = L'\0';
    }
  }

  Result->Type = EFI_IFR_TYPE_STRING;
  //Result->Value.string = NewString (SubString, FormSet->HiiHandle);

  FreePool (String);

  return Status;
}

/**
  Evaluate opcode EFI_IFR_TOKEN.

  @param  FormSet                Formset which contains this opcode.
  @param  Result                 Evaluation result for this opcode.

  @retval EFI_SUCCESS            Opcode evaluation success.
  @retval Other                  Opcode evaluation failed.

**/
EFI_STATUS
IfrToken (
  IN FORM_BROWSER_FORMSET  *FormSet,
  OUT  EFI_HII_VALUE       *Result
  )
{
  EFI_STATUS     Status;
  EFI_HII_VALUE  Value;
  CHAR16         *String[2];
  UINTN          Count;
  CHAR16         *Delimiter;
  CHAR16         *SubString;
  CHAR16         *StringPtr;
  UINTN          Index;

  Status = PopExpression (&Value);
  if (EFI_ERROR (Status)) {
    return Status;
  }
  if (Value.Type > EFI_IFR_TYPE_NUM_SIZE_64) {
    return EFI_UNSUPPORTED;
  }
  Count = (UINTN) Value.Value.u64;

  //
  // String[0] - Delimiter
  // String[1] - The string to search
  //
  String[0] = NULL;
  String[1] = NULL;
  for (Index = 0; Index < 2; Index++) {
    Status = PopExpression (&Value);
    if (EFI_ERROR (Status)) {
      goto Done;
    }

    if (Value.Type != EFI_IFR_TYPE_STRING) {
      Status = EFI_UNSUPPORTED;
      goto Done;
    }

    String[Index] = GetToken (Value.Value.string, FormSet->UnicodeBinary);
    if (String[Index] == NULL) {
      Status = EFI_NOT_FOUND;
      goto Done;
    }
  }

  Delimiter = String[0];
  SubString = String[1];
  while (Count > 0) {
    SubString = StrStr (SubString, Delimiter);
    if (SubString != NULL) {
      //
      // Skip over the delimiter
      //
      SubString = SubString + FceStrLen (Delimiter);
    } else {
      break;
    }
    Count--;
  }

  if (SubString == NULL) {
    //
    // nth delimited sub-string not found, push an empty string
    //
    SubString = gEmptyString;
  } else {
    //
    // Put a NULL terminator for nth delimited sub-string
    //
    StringPtr = StrStr (SubString, Delimiter);
    if (StringPtr != NULL) {
      *StringPtr = L'\0';
    }
  }

  Result->Type = EFI_IFR_TYPE_STRING;
  //Result->Value.string = NewString (SubString, FormSet->HiiHandle);

Done:
  if (String[0] != NULL) {
    FreePool (String[0]);
  }
  if (String[1] != NULL) {
    FreePool (String[1]);
  }

  return Status;
}


/**
  Evaluate opcode EFI_IFR_SPAN.

  @param  FormSet                Formset which contains this opcode.
  @param  Flags                  FIRST_MATCHING or FIRST_NON_MATCHING.
  @param  Result                 Evaluation result for this opcode.

  @retval EFI_SUCCESS            Opcode evaluation success.
  @retval Other                  Opcode evaluation failed.

**/
EFI_STATUS
IfrSpan (
  IN FORM_BROWSER_FORMSET  *FormSet,
  IN UINT8                 Flags,
  OUT  EFI_HII_VALUE       *Result
  )
{
  EFI_STATUS     Status;
  EFI_HII_VALUE  Value;
  CHAR16         *String[2];
  CHAR16         *Charset;
  UINTN          Base;
  UINTN          Index;
  CHAR16         *StringPtr;
  BOOLEAN        Found;

  Status = PopExpression (&Value);
  if (EFI_ERROR (Status)) {
    return Status;
  }
  if (Value.Type > EFI_IFR_TYPE_NUM_SIZE_64) {
    return EFI_UNSUPPORTED;
  }
  Base = (UINTN) Value.Value.u64;

  //
  // String[0] - Charset
  // String[1] - The string to search
  //
  String[0] = NULL;
  String[1] = NULL;
  for (Index = 0; Index < 2; Index++) {
    Status = PopExpression (&Value);
    if (EFI_ERROR (Status)) {
      goto Done;
    }

    if (Value.Type != EFI_IFR_TYPE_STRING) {
      Status = EFI_UNSUPPORTED;
      goto Done;
    }

    String[Index] = GetToken (Value.Value.string, FormSet->UnicodeBinary);
    if (String [Index] == NULL) {
      Status = EFI_NOT_FOUND;
      goto Done;
    }
  }

  if (Base >= FceStrLen (String[1])) {
    Status = EFI_UNSUPPORTED;
    goto Done;
  }

  Found = FALSE;
  StringPtr = String[1] + Base;
  Charset = String[0];
  while (*StringPtr != 0 && !Found) {
    Index = 0;
    while (Charset[Index] != 0) {
      if ((*StringPtr >= Charset[Index]) && (*StringPtr <= Charset[Index + 1])) {
        if (Flags == EFI_IFR_FLAGS_FIRST_MATCHING) {
          Found = TRUE;
          break;
        }
      } else {
        if (Flags == EFI_IFR_FLAGS_FIRST_NON_MATCHING) {
          Found = TRUE;
          break;
        }
      }
      //
      // Skip characters pair representing low-end of a range and high-end of a range
      //
      Index += 2;
    }

    if (!Found) {
      StringPtr++;
    }
  }

  Result->Type = EFI_IFR_TYPE_NUM_SIZE_64;
  Result->Value.u64 = StringPtr - String[1];

Done:
  if (String[0] != NULL) {
    FreePool (String[0]);
  }
  if (String[1] != NULL) {
    FreePool (String[1]);
  }

  return Status;
}


/**
  Zero extend integer/boolean/date/time to UINT64 for comparing.

  @param  Value                  HII Value to be converted.

**/
VOID
ExtendValueToU64 (
  IN  EFI_HII_VALUE   *Value
  )
{
  UINT64  Temp;

  Temp = 0;
  switch (Value->Type) {
  case EFI_IFR_TYPE_NUM_SIZE_8:
    Temp = Value->Value.u8;
    break;

  case EFI_IFR_TYPE_NUM_SIZE_16:
    Temp = Value->Value.u16;
    break;

  case EFI_IFR_TYPE_NUM_SIZE_32:
    Temp = Value->Value.u32;
    break;

  case EFI_IFR_TYPE_BOOLEAN:
    Temp = Value->Value.b;
    break;

  case EFI_IFR_TYPE_TIME:
    Temp = Value->Value.u32 & 0xffffff;
    break;

  case EFI_IFR_TYPE_DATE:
    Temp = Value->Value.u32;
    break;

  default:
    return;
  }

  Value->Value.u64 = Temp;
}


/**
  Compare two Hii value.

  @param  Value1                 Expression value to compare on left-hand.
  @param  Value2                 Expression value to compare on right-hand.
  @param  FormSet                The pointer to the Formset.

  @retval EFI_INVALID_PARAMETER  Could not perform compare on two values.
  @retval 0                      Two operators equal.
  @return Positive value if Value1 is greater than Value2.
  @retval Negative value if Value1 is less than Value2.

**/
INTN
CompareHiiValue (
  IN  EFI_HII_VALUE        *Value1,
  IN  EFI_HII_VALUE        *Value2,
  IN FORM_BROWSER_FORMSET  *FormSet
  )
{
  INTN    Result;
  INT64   Temp64;
  CHAR16  *Str1;
  CHAR16  *Str2;

  if ((Value1->Type >= EFI_IFR_TYPE_OTHER) || (Value2->Type >= EFI_IFR_TYPE_OTHER) ) {
    return EFI_INVALID_PARAMETER;
  }

  if ((Value1->Type == EFI_IFR_TYPE_STRING) || (Value2->Type == EFI_IFR_TYPE_STRING) ) {
    if (Value1->Type != Value2->Type) {
      //
      // Both Operator should be type of String
      //
      return EFI_INVALID_PARAMETER;
    }

    if ((Value1->Value.string == 0) || (Value2->Value.string == 0)) {
      //
      // StringId 0 is reserved
      //
      return EFI_INVALID_PARAMETER;
    }

    if (Value1->Value.string == Value2->Value.string) {
      return 0;
    }

    Str1 = GetToken (Value1->Value.string, FormSet->UnicodeBinary);
    if (Str1 == NULL) {
      //
      // String not found
      //
      return EFI_INVALID_PARAMETER;
    }

    Str2 = GetToken (Value2->Value.string, FormSet->UnicodeBinary);
    if (Str2 == NULL) {
      FreePool (Str1);
      return EFI_INVALID_PARAMETER;
    }

    Result = FceStrCmp (Str1, Str2);

    FreePool (Str1);
    FreePool (Str2);

    return Result;
  }

  //
  // Take remain types(integer, boolean, date/time) as integer
  //
  Temp64 = (INT64) (Value1->Value.u64 - Value2->Value.u64);
  if (Temp64 > 0) {
    Result = 1;
  } else if (Temp64 < 0) {
    Result = -1;
  } else {
    Result = 0;
  }

  return Result;
}

/**
  Tell whether this Operand is an constant Expression or not

  @param  Operand                Operand of an IFR OpCode.

  @retval TRUE                   This is an Expression OpCode.
  @retval FALSE                  Not an Expression OpCode.

**/
BOOLEAN
IsConstantExpressionOpCode (
  IN UINT8              Operand
  )
{
  if ((Operand == EFI_IFR_EQ_ID_VAL_OP)      ||
      (Operand == EFI_IFR_EQ_ID_ID_OP)       ||
      (Operand == EFI_IFR_EQ_ID_VAL_LIST_OP )||
      (Operand == EFI_IFR_QUESTION_REF1_OP)  ||
      (Operand == EFI_IFR_QUESTION_REF2_OP)  ||
      (Operand == EFI_IFR_QUESTION_REF3_OP)  ||
      (Operand == EFI_IFR_THIS_OP )          ||
      (Operand == EFI_IFR_SECURITY_OP)       ||
      (Operand == EFI_IFR_GET_OP)            ||
      (Operand == EFI_IFR_SET_OP)
      ) {
    return FALSE;
  } else {
    return TRUE;
  }
}

/**
  Update the HiiValue of question from its variable.

  @param  FormSet        FormSet associated with this expression.
  @param  Question       The pointer to the Question

  @return EFI_SUCCESS
  @return EFI_NOT_FOUND
**/
EFI_STATUS
UpdateHiiValue (
  IN     FORM_BROWSER_FORMSET     *FormSet,
  IN     FORM_BROWSER_STATEMENT   *Question
  )
{
  EFI_STATUS              Status;
  FORMSET_STORAGE         *VarList;
  UINT8                   *VarBuffer;
  EFI_HII_VALUE           *HiiValue;

  Status   = EFI_SUCCESS;
  HiiValue = &Question->HiiValue;

  Status = SearchVarStorage (
             Question,
             NULL,
             Question->VarStoreInfo.VarOffset,
             FormSet->StorageListHead,
             (CHAR8 **)&VarBuffer,
             &VarList
             );
    if (EFI_ERROR(Status)) {
      return Status;
    }
    if (Question->QuestionReferToBitField) {
      GetBitsQuestionValue (Question, VarBuffer, &HiiValue->Value.u32);
    } else {
      CopyMem (&HiiValue->Value.u64, VarBuffer, Question->StorageWidth);
    }
    return Status;
}
/**
  Evaluate the result of a HII expression.

  If Expression is NULL, then ASSERT.

  @param  FormSet                FormSet associated with this expression.
  @param  Form                   Form associated with this expression.
  @param  Expression             Expression to be evaluated.
  @param  ConstantExpression     The pointer to the flag of constant expression. If constant, will return TRUE.

  @retval EFI_SUCCESS            The expression evaluated successfuly
  @retval EFI_NOT_FOUND          The Question which referenced by a QuestionId
                                 could not be found.
  @retval EFI_OUT_OF_RESOURCES   There is not enough system memory to grow the
                                 stack.
  @retval EFI_ACCESS_DENIED      The pop operation underflowed the stack
  @retval EFI_INVALID_PARAMETER  Syntax error with the Expression

**/
EFI_STATUS
EvaluateExpression (
  IN FORM_BROWSER_FORMSET  *FormSet,
  IN FORM_BROWSER_FORM     *Form,
  IN OUT FORM_EXPRESSION   *Expression,
  IN OUT BOOLEAN           *ConstantExpression
  )
{
  EFI_STATUS              Status;
  LIST_ENTRY              *Link;
  EXPRESSION_OPCODE       *OpCode;
  FORM_BROWSER_STATEMENT  *Question;
  FORM_BROWSER_STATEMENT  *Question2;
  UINT16                  Index;
  EFI_HII_VALUE           Data1;
  EFI_HII_VALUE           Data2;
  EFI_HII_VALUE           Data3;
  FORM_EXPRESSION         *RuleExpression;
  EFI_HII_VALUE           *Value;
  INTN                    Result;
  CHAR16                  *StrPtr;
  UINT32                  TempValue;
  LIST_ENTRY              *SubExpressionLink;
  FORM_EXPRESSION         *SubExpression;
  UINTN                   StackOffset;
  UINTN                   TempLength;
  CHAR16                  TempStr[5];
  UINT8                   DigitUint8;
  UINT8                   *TempBuffer;

  //
  // Save current stack offset.
  //
  StackOffset = SaveExpressionEvaluationStackOffset ();

  ASSERT (Expression != NULL);
  Expression->Result.Type = EFI_IFR_TYPE_OTHER;

  Link = GetFirstNode (&Expression->OpCodeListHead);
  while (!IsNull (&Expression->OpCodeListHead, Link)) {
    OpCode = EXPRESSION_OPCODE_FROM_LINK (Link);

    Link = GetNextNode (&Expression->OpCodeListHead, Link);

    ZeroMem (&Data1, sizeof (EFI_HII_VALUE));
    ZeroMem (&Data2, sizeof (EFI_HII_VALUE));
    ZeroMem (&Data3, sizeof (EFI_HII_VALUE));

    Value = &Data3;
    Value->Type = EFI_IFR_TYPE_BOOLEAN;
    Status = EFI_SUCCESS;

    //
    // Check whether it is a constant expression or not
    //
    if (*ConstantExpression) {
      *ConstantExpression = IsConstantExpressionOpCode (OpCode->Operand);
    }

    switch (OpCode->Operand) {
    //
    // Built-in functions
    //
    case EFI_IFR_EQ_ID_VAL_OP:
      Question = IdToQuestion (FormSet, Form, OpCode->QuestionId);
      if (Question == NULL) {
        Status = EFI_NOT_FOUND;
        goto Done;
      }
      UpdateHiiValue (FormSet, Question);
      Result = CompareHiiValue (&Question->HiiValue, &OpCode->Value, FormSet);
      if ((EFI_STATUS)Result == EFI_INVALID_PARAMETER) {
        Status = EFI_INVALID_PARAMETER;
        goto Done;
      }
      Value->Value.b = (BOOLEAN) ((Result == 0) ? TRUE : FALSE);
      break;

    case EFI_IFR_EQ_ID_ID_OP:
      Question = IdToQuestion (FormSet, Form, OpCode->QuestionId);
      if (Question == NULL) {
        Status = EFI_NOT_FOUND;
        goto Done;
      }

      Question2 = IdToQuestion (FormSet, Form, OpCode->QuestionId2);
      if (Question2 == NULL) {
        Status = EFI_NOT_FOUND;
        goto Done;
      }
      UpdateHiiValue (FormSet, Question);
      UpdateHiiValue (FormSet, Question2);
      Result = CompareHiiValue (&Question->HiiValue, &Question2->HiiValue, FormSet);
      if ((EFI_STATUS)Result == EFI_INVALID_PARAMETER) {
        Status = EFI_INVALID_PARAMETER;
        goto Done;
      }
      Value->Value.b = (BOOLEAN) ((Result == 0) ? TRUE : FALSE);
      break;

    case EFI_IFR_EQ_ID_VAL_LIST_OP:

      Question = IdToQuestion (FormSet, Form, OpCode->QuestionId);
      if (Question == NULL) {
        Status = EFI_NOT_FOUND;
        goto Done;
      }
      UpdateHiiValue (FormSet, Question);
      Value->Value.b = FALSE;
      for (Index =0; Index < OpCode->ListLength; Index++) {
        if (Question->HiiValue.Value.u16 == OpCode->ValueList[Index]) {
          Value->Value.b = TRUE;
          break;
        }
      }
      break;

    case EFI_IFR_DUP_OP:
      Status = PopExpression (Value);
      if (EFI_ERROR (Status)) {
        goto Done;
      }

      Status = PushExpression (Value);
      break;

    case EFI_IFR_QUESTION_REF1_OP:
    case EFI_IFR_THIS_OP:
      Question = IdToQuestion (FormSet, Form, OpCode->QuestionId);
      if (Question == NULL) {
        Status = EFI_NOT_FOUND;
        goto Done;
      }
      UpdateHiiValue (FormSet, Question);
      Value = &Question->HiiValue;
      break;

    case EFI_IFR_SECURITY_OP:
      //
      // Do nothing, as no need for static scaning
      //
      break;

    case EFI_IFR_GET_OP:
      //
      // Get Value from VarStore buffer, EFI VarStore, Name/Value VarStore.
      //
      Value->Type = EFI_IFR_TYPE_UNDEFINED;
      Value->Value.u8 = 0;
      if (OpCode->VarStorage != NULL) {
        switch (OpCode->VarStorage->Type) {
        case EFI_IFR_VARSTORE_OP:
      //
          // Get value from Buffer
          //
          Value->Type = OpCode->ValueType;
          CopyMem (&Value->Value, OpCode->VarStorage->Buffer + OpCode->VarStoreInfo.VarOffset, OpCode->ValueWidth);
      break;

        case EFI_IFR_VARSTORE_EFI_OP:
          //
          // Get value from Buffer
          //
      if (OpCode->VarStorage->NewEfiVarstore) {
            Value->Type = OpCode->ValueType;
            CopyMem (&Value->Value, OpCode->VarStorage->Buffer + OpCode->VarStoreInfo.VarOffset, OpCode->ValueWidth);
      } else {
        CopyMem (&Value->Value, OpCode->VarStorage->Buffer, OpCode->ValueWidth);
      }


      break;
        case EFI_HII_VARSTORE_NAME_VALUE:
          if (OpCode->ValueType != EFI_IFR_TYPE_STRING) {
            //
            // Get value from string except for STRING value.
            //
            Status = GetValueByName (OpCode->VarStorage, OpCode->ValueName, &StrPtr);
            if (!EFI_ERROR (Status)) {
              ASSERT (StrPtr != NULL);
              TempLength = FceStrLen (StrPtr);
              if (OpCode->ValueWidth >= ((TempLength + 1) / 2)) {
                Value->Type = OpCode->ValueType;
                TempBuffer = (UINT8 *) &Value->Value;
                ZeroMem (TempStr, sizeof (TempStr));
                for (Index = 0; Index < TempLength; Index ++) {
                  TempStr[0] = StrPtr[TempLength - Index - 1];
                  DigitUint8 = (UINT8) FceStrHexToUint64 (TempStr);
                  if ((Index & 1) == 0) {
                    TempBuffer [Index/2] = DigitUint8;
                  } else {
                    TempBuffer [Index/2] = (UINT8) ((DigitUint8 << 4) + TempBuffer [Index/2]);
                  }
                }
              }
              free (StrPtr);
              StrPtr = NULL;
            }
          }
          break;
        default:
          //
          // Not recognize storage.
          //
          Status = EFI_UNSUPPORTED;
          goto Done;
        }
      }

      break;

    case EFI_IFR_QUESTION_REF3_OP:
      if (OpCode->DevicePath == 0) {
        //
        // EFI_IFR_QUESTION_REF3
        // Pop an expression from the expression stack
        //
        Status = PopExpression (Value);
        if (EFI_ERROR (Status)) {
          goto Done;
        }

        //
        // Validate the expression value
        //
        if ((Value->Type > EFI_IFR_TYPE_NUM_SIZE_64) || (Value->Value.u64 > 0xffff)) {
          Status = EFI_NOT_FOUND;
          goto Done;
        }

        Question = IdToQuestion (FormSet, Form, Value->Value.u16);
        if (Question == NULL) {
          Status = EFI_NOT_FOUND;
          goto Done;
        }

        //
        // push the questions' value on to the expression stack
        //
        Value = &Question->HiiValue;
      } else {
        //
        // BUGBUG: push 0 for EFI_IFR_QUESTION_REF3_2 and EFI_IFR_QUESTION_REF3_3,
        // since it is impractical to evaluate the value of a Question in another
        // Hii Package list.
        //
        ZeroMem (Value, sizeof (EFI_HII_VALUE));
      }
      break;

    case EFI_IFR_RULE_REF_OP:
      //
      // Find expression for this rule
      //
      RuleExpression = RuleIdToExpression (Form, OpCode->RuleId);
      if (RuleExpression == NULL) {
        Status = EFI_NOT_FOUND;
        goto Done;
      }

      //
      // Evaluate this rule expression
      //
      Status = EvaluateExpression (FormSet, Form, RuleExpression, ConstantExpression);
      if (EFI_ERROR (Status)) {
        goto Done;
      }

      Value = &RuleExpression->Result;
      break;

    case EFI_IFR_STRING_REF1_OP:
      Value->Type = EFI_IFR_TYPE_STRING;
      Value->Value.string = OpCode->Value.Value.string;
      break;

    //
    // Constant
    //
    case EFI_IFR_TRUE_OP:
    case EFI_IFR_FALSE_OP:
    case EFI_IFR_ONE_OP:
    case EFI_IFR_ONES_OP:
    case EFI_IFR_UINT8_OP:
    case EFI_IFR_UINT16_OP:
    case EFI_IFR_UINT32_OP:
    case EFI_IFR_UINT64_OP:
    case EFI_IFR_UNDEFINED_OP:
    case EFI_IFR_VERSION_OP:
    case EFI_IFR_ZERO_OP:
      Value = &OpCode->Value;
      break;

    //
    // unary-op
    //
    case EFI_IFR_LENGTH_OP:
      Status = PopExpression (Value);
      if (EFI_ERROR (Status)) {
        goto Done;
      }
      if (Value->Type != EFI_IFR_TYPE_STRING) {
        Status = EFI_INVALID_PARAMETER;
        goto Done;
      }

      StrPtr = GetToken (Value->Value.string, FormSet->UnicodeBinary);
      if (StrPtr == NULL) {
        Status = EFI_INVALID_PARAMETER;
        goto Done;
      }

      Value->Type = EFI_IFR_TYPE_NUM_SIZE_64;
      Value->Value.u64 = FceStrLen (StrPtr);
      FreePool (StrPtr);
      break;

    case EFI_IFR_NOT_OP:
      Status = PopExpression (Value);
      if (EFI_ERROR (Status)) {
        goto Done;
      }
      if (Value->Type != EFI_IFR_TYPE_BOOLEAN) {
        Status = EFI_INVALID_PARAMETER;
        goto Done;
      }
      Value->Value.b = (BOOLEAN) (!Value->Value.b);
      break;

    case EFI_IFR_QUESTION_REF2_OP:
      //
      // Pop an expression from the expression stack
      //
      Status = PopExpression (Value);
      if (EFI_ERROR (Status)) {
        goto Done;
      }

      //
      // Validate the expression value
      //
      if ((Value->Type > EFI_IFR_TYPE_NUM_SIZE_64) || (Value->Value.u64 > 0xffff)) {
        Status = EFI_NOT_FOUND;
        goto Done;
      }

      Question = IdToQuestion (FormSet, Form, Value->Value.u16);
      if (Question == NULL) {
        Status = EFI_NOT_FOUND;
        goto Done;
      }

      Value = &Question->HiiValue;
      break;

    case EFI_IFR_STRING_REF2_OP:
      //
      // Pop an expression from the expression stack
      //
      Status = PopExpression (Value);
      if (EFI_ERROR (Status)) {
        goto Done;
      }

      //
      // Validate the expression value
      //
      if ((Value->Type > EFI_IFR_TYPE_NUM_SIZE_64) || (Value->Value.u64 > 0xffff)) {
        Status = EFI_NOT_FOUND;
        goto Done;
      }

      Value->Type = EFI_IFR_TYPE_STRING;
      StrPtr = GetToken (Value->Value.u16, FormSet->UnicodeBinary);
      if (StrPtr == NULL) {
        //
        // If String not exit, push an empty string
        //
        //Value->Value.string = NewString (gEmptyString, FormSet->HiiHandle);
      } else {
        Index = (UINT16) Value->Value.u64;
        Value->Value.string = Index;
        FreePool (StrPtr);
      }
      break;

    case EFI_IFR_TO_BOOLEAN_OP:
        //
        // Pop an expression from the expression stack
        //
        Status = PopExpression (Value);
        if (EFI_ERROR (Status)) {
          goto Done;
        }

        //
        // Convert an expression to a Boolean
        //
        if (Value->Type <= EFI_IFR_TYPE_DATE) {
          //
          // When converting from an unsigned integer, zero will be converted to
          // FALSE and any other value will be converted to TRUE.
          //
          Value->Value.b = (BOOLEAN) (Value->Value.u64 != 0);

          Value->Type = EFI_IFR_TYPE_BOOLEAN;
        } else if (Value->Type == EFI_IFR_TYPE_STRING) {
          //
          // When converting from a string, if case-insensitive compare
          // with "true" is True, then push True. If a case-insensitive compare
          // with "false" is True, then push False. Otherwise, push Undefined.
          //
          StrPtr = GetToken (Value->Value.string, FormSet->UnicodeBinary);
          if (StrPtr == NULL) {
            Status = EFI_INVALID_PARAMETER;
            goto Done;
          }

          IfrStrToUpper (StrPtr);
          if (FceStrCmp (StrPtr, L"TRUE") == 0){
            Value->Value.b = TRUE;
          } else if (FceStrCmp (StrPtr, L"FALSE") == 0) {
            Value->Value.b = FALSE;
          } else {
            Status = EFI_INVALID_PARAMETER;
            FreePool (StrPtr);
            goto Done;
          }
          FreePool (StrPtr);
          Value->Type = EFI_IFR_TYPE_BOOLEAN;
        }
      break;

    case EFI_IFR_TO_STRING_OP:
      //Status = IfrToString (FormSet, OpCode->Format, Value);
      break;

    case EFI_IFR_TO_UINT_OP:
      Status = IfrToUint (FormSet, Value);
      break;

    case EFI_IFR_TO_LOWER_OP:
    case EFI_IFR_TO_UPPER_OP:

      Status = PopExpression (Value);
      if (EFI_ERROR (Status)) {
        goto Done;
      }

      if (Value->Type != EFI_IFR_TYPE_STRING) {
        Status = EFI_UNSUPPORTED;
        goto Done;
      }

      StrPtr = GetToken (Value->Value.string, FormSet->UnicodeBinary);
      if (StrPtr == NULL) {
        Status = EFI_NOT_FOUND;
        goto Done;
      }
      //
      // Do nothing here, as these two Opcode are to change or update the String Package
      //
      FreePool (StrPtr);
      break;

    case EFI_IFR_BITWISE_NOT_OP:
      //
      // Pop an expression from the expression stack
      //
      Status = PopExpression (Value);
      if (EFI_ERROR (Status)) {
        goto Done;
      }
      if (Value->Type > EFI_IFR_TYPE_DATE) {
        Status = EFI_INVALID_PARAMETER;
        goto Done;
      }

      Value->Type = EFI_IFR_TYPE_NUM_SIZE_64;
      Value->Value.u64 = ~Value->Value.u64;
      break;

    case EFI_IFR_SET_OP:
      //
      // Pop an expression from the expression stack
      //
      Status = PopExpression (Value);
      if (EFI_ERROR (Status)) {
        goto Done;
      }
      Data1.Type = EFI_IFR_TYPE_BOOLEAN;
      Data1.Value.b = FALSE;
      //
      // Not support SetOpcode for static scaning
      //
      if (OpCode->VarStorage != NULL) {
        switch (OpCode->VarStorage->Type) {

      case EFI_IFR_VARSTORE_OP:
         CopyMem (OpCode->VarStorage->Buffer + OpCode->VarStoreInfo.VarOffset, &Value->Value, OpCode->ValueWidth);
           Data1.Value.b = TRUE;
       break;
        case EFI_IFR_VARSTORE_EFI_OP:
       if (OpCode->VarStorage->NewEfiVarstore) {
              CopyMem (OpCode->VarStorage->Buffer + OpCode->VarStoreInfo.VarOffset, &Value->Value, OpCode->ValueWidth);
              Data1.Value.b = TRUE;
        } else {
          CopyMem (OpCode->VarStorage->Buffer, &Value->Value, OpCode->ValueWidth);
          Data1.Value.b = TRUE;
        }
          break;
        case EFI_HII_VARSTORE_NAME_VALUE:

          break;
          break;
        default:
          //
          // Not recognize storage.
          //
          Status = EFI_UNSUPPORTED;
          goto Done;
          break;
        }
        Value = &Data1;
      }
      break;

    //
    // binary-op
    //
    case EFI_IFR_ADD_OP:
    case EFI_IFR_SUBTRACT_OP:
    case EFI_IFR_MULTIPLY_OP:
    case EFI_IFR_DIVIDE_OP:
    case EFI_IFR_MODULO_OP:
    case EFI_IFR_BITWISE_AND_OP:
    case EFI_IFR_BITWISE_OR_OP:
    case EFI_IFR_SHIFT_LEFT_OP:
    case EFI_IFR_SHIFT_RIGHT_OP:
      //
      // Pop an expression from the expression stack
      //
      Status = PopExpression (&Data2);
      if (EFI_ERROR (Status)) {
        goto Done;
      }
      if (Data2.Type > EFI_IFR_TYPE_DATE) {
        Status = EFI_INVALID_PARAMETER;
        goto Done;
      }

      //
      // Pop another expression from the expression stack
      //
      Status = PopExpression (&Data1);
      if (EFI_ERROR (Status)) {
        goto Done;
      }
      if (Data1.Type > EFI_IFR_TYPE_DATE) {
        Status = EFI_INVALID_PARAMETER;
        goto Done;
      }

      Value->Type = EFI_IFR_TYPE_NUM_SIZE_64;

      switch (OpCode->Operand) {
        case EFI_IFR_ADD_OP:
          Value->Value.u64 = Data1.Value.u64 + Data2.Value.u64;
          break;

        case EFI_IFR_SUBTRACT_OP:
          Value->Value.u64 = Data1.Value.u64 - Data2.Value.u64;
          break;

        case EFI_IFR_MULTIPLY_OP:
          Value->Value.u64 = MultU64x32 (Data1.Value.u64, (UINT32) Data2.Value.u64);
          break;

        case EFI_IFR_DIVIDE_OP:
          Value->Value.u64 = DivU64x32 (Data1.Value.u64, (UINT32) Data2.Value.u64);
          break;

        case EFI_IFR_MODULO_OP:
          DivU64x32Remainder  (Data1.Value.u64, (UINT32) Data2.Value.u64, &TempValue);
          Value->Value.u64 = TempValue;
          break;

        case EFI_IFR_BITWISE_AND_OP:
          Value->Value.u64 = Data1.Value.u64 & Data2.Value.u64;
          break;

        case EFI_IFR_BITWISE_OR_OP:
          Value->Value.u64 = Data1.Value.u64 | Data2.Value.u64;
          break;

        case EFI_IFR_SHIFT_LEFT_OP:
          Value->Value.u64 = LShiftU64 (Data1.Value.u64, (UINTN) Data2.Value.u64);
          break;

        case EFI_IFR_SHIFT_RIGHT_OP:
          Value->Value.u64 = RShiftU64 (Data1.Value.u64, (UINTN) Data2.Value.u64);
          break;

        default:
          break;
      }
      break;

    case EFI_IFR_AND_OP:
    case EFI_IFR_OR_OP:
      //
      // Two Boolean operator
      //
      Status = PopExpression (&Data2);
      if (EFI_ERROR (Status)) {
        goto Done;
      }
      if (Data2.Type != EFI_IFR_TYPE_BOOLEAN) {
        Status = EFI_INVALID_PARAMETER;
        goto Done;
      }

      //
      // Pop another expression from the expression stack
      //
      Status = PopExpression (&Data1);
      if (EFI_ERROR (Status)) {
        goto Done;
      }
      if (Data1.Type != EFI_IFR_TYPE_BOOLEAN) {
        Status = EFI_INVALID_PARAMETER;
        goto Done;
      }

      if (OpCode->Operand == EFI_IFR_AND_OP) {
        Value->Value.b = (BOOLEAN) (Data1.Value.b && Data2.Value.b);
      } else {
        Value->Value.b = (BOOLEAN) (Data1.Value.b || Data2.Value.b);
      }
      break;

    case EFI_IFR_EQUAL_OP:
    case EFI_IFR_NOT_EQUAL_OP:
    case EFI_IFR_GREATER_EQUAL_OP:
    case EFI_IFR_GREATER_THAN_OP:
    case EFI_IFR_LESS_EQUAL_OP:
    case EFI_IFR_LESS_THAN_OP:
      //
      // Compare two integer, string, boolean or date/time
      //
      Status = PopExpression (&Data2);
      if (EFI_ERROR (Status)) {
        goto Done;
      }
      if ((Data2.Type > EFI_IFR_TYPE_BOOLEAN) && (Data2.Type != EFI_IFR_TYPE_STRING)) {
        Status = EFI_INVALID_PARAMETER;
        goto Done;
      }

      //
      // Pop another expression from the expression stack
      //
      Status = PopExpression (&Data1);
      if (EFI_ERROR (Status)) {
        goto Done;
      }

      Result = CompareHiiValue (&Data1, &Data2, FormSet);
      if ((EFI_STATUS)Result == EFI_INVALID_PARAMETER) {
        Status = EFI_INVALID_PARAMETER;
        goto Done;
      }

      switch (OpCode->Operand) {
      case EFI_IFR_EQUAL_OP:
        Value->Value.b = (BOOLEAN) ((Result == 0) ? TRUE : FALSE);
        break;

      case EFI_IFR_NOT_EQUAL_OP:
        Value->Value.b = (BOOLEAN) ((Result != 0) ? TRUE : FALSE);
        break;

      case EFI_IFR_GREATER_EQUAL_OP:
        Value->Value.b = (BOOLEAN) ((Result >= 0) ? TRUE : FALSE);
        break;

      case EFI_IFR_GREATER_THAN_OP:
        Value->Value.b = (BOOLEAN) ((Result > 0) ? TRUE : FALSE);
        break;

      case EFI_IFR_LESS_EQUAL_OP:
        Value->Value.b = (BOOLEAN) ((Result <= 0) ? TRUE : FALSE);
        break;

      case EFI_IFR_LESS_THAN_OP:
        Value->Value.b = (BOOLEAN) ((Result < 0) ? TRUE : FALSE);
        break;

      default:
        break;
      }
      break;

    case EFI_IFR_MATCH_OP:
      Status = IfrMatch (FormSet, Value);
      break;

    case EFI_IFR_CATENATE_OP:
      Status = IfrCatenate (FormSet, Value);
      break;

    //
    // ternary-op
    //
    case EFI_IFR_CONDITIONAL_OP:
      //
      // Pop third expression from the expression stack
      //
      Status = PopExpression (&Data3);
      if (EFI_ERROR (Status)) {
        goto Done;
      }

      //
      // Pop second expression from the expression stack
      //
      Status = PopExpression (&Data2);
      if (EFI_ERROR (Status)) {
        goto Done;
      }

      //
      // Pop first expression from the expression stack
      //
      Status = PopExpression (&Data1);
      if (EFI_ERROR (Status)) {
        goto Done;
      }
      if (Data1.Type != EFI_IFR_TYPE_BOOLEAN) {
        Status = EFI_INVALID_PARAMETER;
        goto Done;
      }

      if (Data1.Value.b) {
        Value = &Data3;
      } else {
        Value = &Data2;
      }
      break;

    case EFI_IFR_FIND_OP:
      Status = IfrFind (FormSet, OpCode->Format, Value);
      break;

    case EFI_IFR_MID_OP:
      Status = IfrMid (FormSet, Value);
      break;

    case EFI_IFR_TOKEN_OP:
      Status = IfrToken (FormSet, Value);
      break;

    case EFI_IFR_SPAN_OP:
      Status = IfrSpan (FormSet, OpCode->Flags, Value);
      break;

    case EFI_IFR_MAP_OP:
      //
      // Pop the check value
      //
      Status = PopExpression (&Data1);
      if (EFI_ERROR (Status)) {
        goto Done;
      }
      //
      // Check MapExpression list is valid.
      //
      if (OpCode->MapExpressionList.ForwardLink == NULL) {
        Status = EFI_INVALID_PARAMETER;
        goto Done;
      }
      //
      // Go through map expression list.
      //
      SubExpressionLink = GetFirstNode(&OpCode->MapExpressionList);
      while (!IsNull (&OpCode->MapExpressionList, SubExpressionLink)) {
        SubExpression = FORM_EXPRESSION_FROM_LINK (SubExpressionLink);
        //
        // Evaluate the first expression in this pair.
        //
        Status = EvaluateExpression (FormSet, Form, SubExpression, ConstantExpression);
        if (EFI_ERROR (Status)) {
          goto Done;
        }
        //
        // Compare the expression value with current value
        //
        if (CompareHiiValue (&Data1, &SubExpression->Result, FormSet) == 0) {
          //
          // Try get the map value.
          //
          SubExpressionLink = GetNextNode (&OpCode->MapExpressionList, SubExpressionLink);
          if (IsNull (&OpCode->MapExpressionList, SubExpressionLink)) {
            Status = EFI_INVALID_PARAMETER;
            goto Done;
          }
          SubExpression = FORM_EXPRESSION_FROM_LINK (SubExpressionLink);
          Status = EvaluateExpression (FormSet, Form, SubExpression, ConstantExpression);
          if (EFI_ERROR (Status)) {
            goto Done;
          }
          Value = &SubExpression->Result;
          break;
        }
        //
        // Skip the second expression on this pair.
        //
        SubExpressionLink = GetNextNode (&OpCode->MapExpressionList, SubExpressionLink);
        if (IsNull (&OpCode->MapExpressionList, SubExpressionLink)) {
          Status = EFI_INVALID_PARAMETER;
          goto Done;
        }
        //
        // Goto the first expression on next pair.
        //
        SubExpressionLink = GetNextNode (&OpCode->MapExpressionList, SubExpressionLink);
      }

      //
      // No map value is found.
      //
      if (IsNull (&OpCode->MapExpressionList, SubExpressionLink)) {
        Value->Type = EFI_IFR_TYPE_UNDEFINED;
        Value->Value.u8 = 0;
      }
      break;

    default:
      break;
    }
    if (EFI_ERROR (Status)) {
      goto Done;
    }

    Status = PushExpression (Value);
    if (EFI_ERROR (Status)) {
      goto Done;
    }
  }

  //
  // Pop the final result from expression stack
  //
  Value = &Data1;
  Status = PopExpression (Value);
  if (EFI_ERROR (Status)) {
    goto Done;
  }

  //
  // After evaluating an expression, there should be only one value left on the expression stack
  //
  if (PopExpression (Value) != EFI_ACCESS_DENIED) {
    Status = EFI_INVALID_PARAMETER;
  }

Done:
  RestoreExpressionEvaluationStackOffset (StackOffset);
  if (!EFI_ERROR (Status)) {
    CopyMem (&Expression->Result, Value, sizeof (EFI_HII_VALUE));
  }

  return Status;
}