QScript::SyntaxChecker Class Reference

#include <qscriptsyntaxchecker_p.h>

Inheritance diagram for QScript::SyntaxChecker:

Classes
struct	Result

Public Types
enum	State { Error, Intermediate, Valid }

Public Functions
Result	checkSyntax (const QString &code)
	SyntaxChecker ()
	~SyntaxChecker ()

Protected Functions
bool	automatic (QScript::Lexer *lexer, int token) const
void	reallocateStack ()

Protected Variables
int	stack_size
int *	state_stack
int	tos

Additional Inherited Members
Protected Types inherited from QScriptGrammar
enum	{   EOF_SYMBOL = 0, T_AND = 1, T_AND_AND = 2, T_AND_EQ = 3,   T_AUTOMATIC_SEMICOLON = 62, T_BREAK = 4, T_CASE = 5, T_CATCH = 6,   T_COLON = 7, T_COMMA = 8, T_CONST = 81, T_CONTINUE = 9,   T_DEBUGGER = 82, T_DEFAULT = 10, T_DELETE = 11, T_DIVIDE_ = 12,   T_DIVIDE_EQ = 13, T_DO = 14, T_DOT = 15, T_ELSE = 16,   T_EQ = 17, T_EQ_EQ = 18, T_EQ_EQ_EQ = 19, T_FALSE = 80,   T_FINALLY = 20, T_FOR = 21, T_FUNCTION = 22, T_GE = 23,   T_GT = 24, T_GT_GT = 25, T_GT_GT_EQ = 26, T_GT_GT_GT = 27,   T_GT_GT_GT_EQ = 28, T_IDENTIFIER = 29, T_IF = 30, T_IN = 31,   T_INSTANCEOF = 32, T_LBRACE = 33, T_LBRACKET = 34, T_LE = 35,   T_LPAREN = 36, T_LT = 37, T_LT_LT = 38, T_LT_LT_EQ = 39,   T_MINUS = 40, T_MINUS_EQ = 41, T_MINUS_MINUS = 42, T_NEW = 43,   T_NOT = 44, T_NOT_EQ = 45, T_NOT_EQ_EQ = 46, T_NULL = 78,   T_NUMERIC_LITERAL = 47, T_OR = 48, T_OR_EQ = 49, T_OR_OR = 50,   T_PLUS = 51, T_PLUS_EQ = 52, T_PLUS_PLUS = 53, T_QUESTION = 54,   T_RBRACE = 55, T_RBRACKET = 56, T_REMAINDER = 57, T_REMAINDER_EQ = 58,   T_RESERVED_WORD = 83, T_RETURN = 59, T_RPAREN = 60, T_SEMICOLON = 61,   T_STAR = 63, T_STAR_EQ = 64, T_STRING_LITERAL = 65, T_SWITCH = 66,   T_THIS = 67, T_THROW = 68, T_TILDE = 69, T_TRUE = 79,   T_TRY = 70, T_TYPEOF = 71, T_VAR = 72, T_VOID = 73,   T_WHILE = 74, T_WITH = 75, T_XOR = 76, T_XOR_EQ = 77,   ACCEPT_STATE = 237, RULE_COUNT = 269, STATE_COUNT = 468, TERMINAL_COUNT = 84,   NON_TERMINAL_COUNT = 88, GOTO_INDEX_OFFSET = 468, GOTO_INFO_OFFSET = 1562, GOTO_CHECK_OFFSET = 1562 }
Static Protected Functions inherited from QScriptGrammar
static int	nt_action (int state, int nt)
static int	t_action (int state, int token)
Static Protected Variables inherited from QScriptGrammar
static const short	action_check []
static const short	action_default []
static const short	action_index []
static const short	action_info []
static const short	goto_default []
static const short	lhs []
static const short	rhs []
static const int	rule_index []
static const int	rule_info []
static const char *const	spell []

Detailed Description

Definition at line 48 of file qscriptsyntaxchecker_p.h.

Enumerations

State

enum QScript::SyntaxChecker::State

Enumerator
Error
Intermediate
Valid

Definition at line 51 of file qscriptsyntaxchecker_p.h.

               {
        Error,
        Intermediate,
        Valid,
    };

Constructors and Destructors

SyntaxChecker()

QScript::SyntaxChecker::SyntaxChecker

(

)

Definition at line 34 of file qscriptsyntaxchecker.cpp.

                            :
    tos(0),
    stack_size(0),
    state_stack(0)
{
}

~SyntaxChecker()

QScript::SyntaxChecker::~SyntaxChecker

(

)

Definition at line 41 of file qscriptsyntaxchecker.cpp.

{
    if (stack_size) {
        qFree(state_stack);
    }
}

Functions

automatic()

bool QScript::SyntaxChecker::automatic ( QScript::Lexer *  lexer, int  token  ) const

protected

Definition at line 48 of file qscriptsyntaxchecker.cpp.

Referenced by checkSyntax().

{
    return token == T_RBRACE || token == 0 || lexer->prevTerminator();
}

checkSyntax()

SyntaxChecker::Result QScript::SyntaxChecker::checkSyntax

(

const QString &

code

)

Definition at line 53 of file qscriptsyntaxchecker.cpp.

Referenced by QScriptEnginePrivate::canEvaluate(), and QScriptEnginePrivate::checkSyntax().

{
  const int INITIAL_STATE = 0;
  QScript::Lexer lexer (/*engine=*/ 0);
  lexer.setCode(code, /*lineNo*/ 1);

  int yytoken = -1;
  int saved_yytoken = -1;
  QString error_message;
  int error_lineno = -1;
  int error_column = -1;
  State checkerState = Valid;

  reallocateStack();

  tos = 0;
  state_stack[++tos] = INITIAL_STATE;

  while (true)
    {
      const int state = state_stack [tos];
      if (yytoken == -1 && - TERMINAL_COUNT != action_index [state])
        {
          if (saved_yytoken == -1)
            yytoken = lexer.lex();
          else
            {
              yytoken = saved_yytoken;
              saved_yytoken = -1;
            }
        }

      int act = t_action (state, yytoken);

      if (act == ACCEPT_STATE) {
          if (lexer.error() == QScript::Lexer::UnclosedComment)
              checkerState = Intermediate;
          else
              checkerState = Valid;
          break;
      } else if (act > 0) {
          if (++tos == stack_size)
            reallocateStack();

          state_stack [tos] = act;
          yytoken = -1;
        }

      else if (act < 0)
        {
          int r = - act - 1;

          tos -= rhs [r];
          act = state_stack [tos++];

          if ((r == Q_SCRIPT_REGEXPLITERAL_RULE1)
              || (r == Q_SCRIPT_REGEXPLITERAL_RULE2)) {
              // Skip the rest of the RegExp literal
              bool rx = lexer.scanRegExp();
              if (!rx) {
                  checkerState = Intermediate;
                  break;
              }
          }

          state_stack [tos] = nt_action (act, lhs [r] - TERMINAL_COUNT);
        }

      else
        {
          if (saved_yytoken == -1 && automatic (&lexer, yytoken) && t_action (state, T_AUTOMATIC_SEMICOLON) > 0)
            {
              saved_yytoken = yytoken;
              yytoken = T_SEMICOLON;
              continue;
            }

          else if ((state == INITIAL_STATE) && (yytoken == 0)) {
              // accept empty input
              yytoken = T_SEMICOLON;
              continue;
          }

          int ers = state;
          int shifts = 0;
          int reduces = 0;
          int expected_tokens [3];
          for (int tk = 0; tk < TERMINAL_COUNT; ++tk)
            {
              int k = t_action (ers, tk);

              if (! k)
                continue;
              else if (k < 0)
                ++reduces;
              else if (spell [tk])
                {
                  if (shifts < 3)
                    expected_tokens [shifts] = tk;
                  ++shifts;
                }
            }

          error_message.clear ();
          if (shifts && shifts < 3)
            {
              bool first = true;

              for (int s = 0; s < shifts; ++s)
                {
                  if (first)
                    error_message += QLatin1String ("Expected ");
                  else
                    error_message += QLatin1String (", ");

                  first = false;
                  error_message += QLatin1Char('`');
                  error_message += QLatin1String (spell [expected_tokens [s]]);
                  error_message += QLatin1Char('\'');
                }
            }

          if (error_message.isEmpty())
              error_message = lexer.errorMessage();

          error_lineno = lexer.startLineNo();
          error_column = lexer.startColumnNo();
          checkerState = Error;
          break;
        }
    }

  if (checkerState == Error) {
      if (lexer.error() == QScript::Lexer::UnclosedComment)
          checkerState = Intermediate;
      else if (yytoken == 0)
          checkerState = Intermediate;
  }
  return Result(checkerState, error_lineno, error_column, error_message);
}

reallocateStack()

void QScript::SyntaxChecker::reallocateStack ( )

inlineprotected

Definition at line 82 of file qscriptsyntaxchecker_p.h.

Referenced by checkSyntax().

{
    if (! stack_size)
        stack_size = 128;
    else
        stack_size <<= 1;

    state_stack = reinterpret_cast<int*> (qRealloc(state_stack, stack_size * sizeof(int)));
}

Properties

stack_size

int QScript::SyntaxChecker::stack_size

protected

Definition at line 78 of file qscriptsyntaxchecker_p.h.

Referenced by checkSyntax(), reallocateStack(), and ~SyntaxChecker().

state_stack

int* QScript::SyntaxChecker::state_stack

protected

Definition at line 79 of file qscriptsyntaxchecker_p.h.

Referenced by checkSyntax(), reallocateStack(), and ~SyntaxChecker().

tos

int QScript::SyntaxChecker::tos

protected

Definition at line 77 of file qscriptsyntaxchecker_p.h.

Referenced by checkSyntax().

---

The documentation for this class was generated from the following files:

• /src/script/parser/qscriptsyntaxchecker_p.h
• /src/script/parser/qscriptsyntaxchecker.cpp