lalr1.cc

来自「bison 2.0 主要可以用来做语法分析用的」· CC 代码 · 共 1,373 行 · 第 1/3 页

#if YYDEBUG
/*--------------------------------.
| Print this symbol on YYOUTPUT.  |
`--------------------------------*/

void
yy::]b4_parser_class_name[::yysymprint_ (int yytype,
                         const semantic_type* yyvaluep, const location_type* yylocationp)
{
  /* Pacify ``unused variable'' warnings.  */
  (void) yyvaluep;
  (void) yylocationp;
  /* Backward compatibility, but should be removed eventually. */
  std::ostream& cdebug_ = *yycdebug_;
  (void) cdebug_;

  *yycdebug_ << (yytype < yyntokens_ ? "token" : "nterm")
	     << ' ' << yyname_[yytype] << " ("
             << *yylocationp << ": ";
  switch (yytype)
    {
]m4_map([b4_symbol_actions], m4_defn([b4_symbol_printers]))dnl
[      default:
        break;
    }
  *yycdebug_ << ')';
}
#endif /* ! YYDEBUG */

void
yy::]b4_parser_class_name[::yydestruct_ (const char* yymsg,
                         int yytype, semantic_type* yyvaluep, location_type* yylocationp)
{
  /* Pacify ``unused variable'' warnings.  */
  (void) yymsg;
  (void) yyvaluep;
  (void) yylocationp;

  YY_SYMBOL_PRINT (yymsg, yytype, yyvaluep, yylocationp);

  switch (yytype)
    {
]m4_map([b4_symbol_actions], m4_defn([b4_symbol_destructors]))[
      default:
        break;
    }
}

void
yy::]b4_parser_class_name[::yypop_ (unsigned int n)
{
  yystate_stack_.pop (n);
  yysemantic_stack_.pop (n);
  yylocation_stack_.pop (n);
}

std::ostream&
yy::]b4_parser_class_name[::debug_stream () const
{
  return *yycdebug_;
}

void
yy::]b4_parser_class_name[::set_debug_stream (std::ostream& o)
{
  yycdebug_ = &o;
}


yy::]b4_parser_class_name[::debug_level_type
yy::]b4_parser_class_name[::debug_level () const
{
  return yydebug_;
}

void
yy::]b4_parser_class_name[::set_debug_level (debug_level_type l)
{
  yydebug_ = l;
}


int
yy::]b4_parser_class_name[::parse ()
{
  YYCDEBUG << "Starting parse" << std::endl;

  yynerrs_ = 0;
  yyerrstatus_ = 0;

  /* Start.  */
  yystate_ = 0;
  yylooka_ = yyempty_;

]m4_ifdef([b4_initial_action], [
m4_pushdef([b4_at_dollar],     [yylloc])dnl
m4_pushdef([b4_dollar_dollar], [yylval])dnl
  /* User initialization code. */
  b4_initial_action
m4_popdef([b4_dollar_dollar])dnl
m4_popdef([b4_at_dollar])dnl
/* Line __line__ of yacc.c.  */
b4_syncline([@oline@], [@ofile@])])dnl

[  /* Initialize the stacks.  The initial state will be pushed in
     yynewstate, since the latter expects the semantical and the
     location values to have been already stored, initialize these
     stacks with a primary value.  */
  yystate_stack_ = state_stack_type (0);
  yysemantic_stack_ = semantic_stack_type (0);
  yylocation_stack_ = location_stack_type (0);
  yysemantic_stack_.push (yylval);
  yylocation_stack_.push (yylloc);

  /* New state.  */
yynewstate:
  yystate_stack_.push (yystate_);
  YYCDEBUG << "Entering state " << yystate_ << std::endl;
  goto yybackup;

  /* Backup.  */
yybackup:

  /* Try to take a decision without look-ahead.  */
  yyn_ = yypact_[yystate_];
  if (yyn_ == yypact_ninf_)
    goto yydefault;

  /* Read a look-ahead token.  */
  if (yylooka_ == yyempty_)
    yylex_ ();

  /* Convert token to internal form.  */
  if (yylooka_ <= yyeof_)
    {
      yylooka_ = yyilooka_ = yyeof_;
      YYCDEBUG << "Now at end of input." << std::endl;
    }
  else
    {
      yyilooka_ = yytranslate_ (yylooka_);
      YY_SYMBOL_PRINT ("Next token is", yyilooka_, &yylval, &yylloc);
    }

  /* If the proper action on seeing token ILOOKA_ is to reduce or to
     detect an error, take that action.  */
  yyn_ += yyilooka_;
  if (yyn_ < 0 || yylast_ < yyn_ || yycheck_[yyn_] != yyilooka_)
    goto yydefault;

  /* Reduce or error.  */
  yyn_ = yytable_[yyn_];
  if (yyn_ < 0)
    {
      if (yyn_ == yytable_ninf_)
	goto yyerrlab;
      else
	{
	  yyn_ = -yyn_;
	  goto yyreduce;
	}
    }
  else if (yyn_ == 0)
    goto yyerrlab;

  /* Accept?  */
  if (yyn_ == yyfinal_)
    goto yyacceptlab;

  /* Shift the look-ahead token.  */
  YY_SYMBOL_PRINT ("Shifting", yyilooka_, &yylval, &yylloc);

  /* Discard the token being shifted unless it is eof.  */
  if (yylooka_ != yyeof_)
    yylooka_ = yyempty_;

  yysemantic_stack_.push (yylval);
  yylocation_stack_.push (yylloc);

  /* Count tokens shifted since error; after three, turn off error
     status.  */
  if (yyerrstatus_)
    --yyerrstatus_;

  yystate_ = yyn_;
  goto yynewstate;

/*-----------------------------------------------------------.
| yydefault -- do the default action for the current state.  |
`-----------------------------------------------------------*/
yydefault:
  yyn_ = yydefact_[yystate_];
  if (yyn_ == 0)
    goto yyerrlab;
  goto yyreduce;

/*-----------------------------.
| yyreduce -- Do a reduction.  |
`-----------------------------*/
yyreduce:
  yylen_ = yyr2_[yyn_];
  /* If LEN_ is nonzero, implement the default value of the action:
     `$$ = $1'.  Otherwise, use the top of the stack.

     Otherwise, the following line sets YYVAL to garbage.
     This behavior is undocumented and Bison
     users should not rely upon it.  */
  if (yylen_)
    yyval = yysemantic_stack_[yylen_ - 1];
  else
    yyval = yysemantic_stack_[0];

  {
    slice<location_type, location_stack_type> slice (yylocation_stack_, yylen_);
    YYLLOC_DEFAULT (yyloc, slice, yylen_);
  }
  YY_REDUCE_PRINT (yyn_);
  switch (yyn_)
    {
      ]b4_actions[
    }

]/* Line __line__ of lalr1.cc.  */
b4_syncline([@oline@], [@ofile@])[

  yypop_ (yylen_);

  YY_STACK_PRINT ();

  yysemantic_stack_.push (yyval);
  yylocation_stack_.push (yyloc);

  /* Shift the result of the reduction.  */
  yyn_ = yyr1_[yyn_];
  yystate_ = yypgoto_[yyn_ - yyntokens_] + yystate_stack_[0];
  if (0 <= yystate_ && yystate_ <= yylast_
      && yycheck_[yystate_] == yystate_stack_[0])
    yystate_ = yytable_[yystate_];
  else
    yystate_ = yydefgoto_[yyn_ - yyntokens_];
  goto yynewstate;

/*------------------------------------.
| yyerrlab -- here on detecting error |
`------------------------------------*/
yyerrlab:
  /* If not already recovering from an error, report this error.  */
  yyreport_syntax_error_ ();

  yyerror_range_[0] = yylloc;
  if (yyerrstatus_ == 3)
    {
      /* If just tried and failed to reuse look-ahead token after an
	 error, discard it.  */

      /* Return failure if at end of input.  */
      if (yylooka_ <= yyeof_)
        {
          /* If at end of input, pop the error token,
	     then the rest of the stack, then return failure.  */
	  if (yylooka_ == yyeof_)
	     for (;;)
	       {
                 yyerror_range_[0] = yylocation_stack_[0];
                 yypop_ ();
		 if (yystate_stack_.height () == 1)
		   YYABORT;
                 yydestruct_ ("Error: popping",
                              yystos_[yystate_stack_[0]],
                              &yysemantic_stack_[0],
                              &yylocation_stack_[0]);
	       }
        }
      else
        {
          yydestruct_ ("Error: discarding", yyilooka_, &yylval, &yylloc);
          yylooka_ = yyempty_;
        }
    }

  /* Else will try to reuse look-ahead token after shifting the error
     token.  */
  goto yyerrlab1;


/*---------------------------------------------------.
| yyerrorlab -- error raised explicitly by YYERROR.  |
`---------------------------------------------------*/
yyerrorlab:

#ifdef __GNUC__
  /* Pacify GCC when the user code never invokes YYERROR and the label
     yyerrorlab therefore never appears in user code.  */
  if (0)
     goto yyerrorlab;
#endif

  yyerror_range_[0] = yylocation_stack_[yylen_ - 1];
  yypop_ (yylen_);
  yystate_ = yystate_stack_[0];
  goto yyerrlab1;

/*-------------------------------------------------------------.
| yyerrlab1 -- common code for both syntax error and YYERROR.  |
`-------------------------------------------------------------*/
yyerrlab1:
  yyerrstatus_ = 3;	/* Each real token shifted decrements this.  */

  for (;;)
    {
      yyn_ = yypact_[yystate_];
      if (yyn_ != yypact_ninf_)
	{
	  yyn_ += yyterror_;
	  if (0 <= yyn_ && yyn_ <= yylast_ && yycheck_[yyn_] == yyterror_)
	    {
	      yyn_ = yytable_[yyn_];
	      if (0 < yyn_)
		break;
	    }
	}

      /* Pop the current state because it cannot handle the error token.  */
      if (yystate_stack_.height () == 1)
	YYABORT;

      yyerror_range_[0] = yylocation_stack_[0];
      yydestruct_ ("Error: popping",
                   yystos_[yystate_],
                   &yysemantic_stack_[0], &yylocation_stack_[0]);
      yypop_ ();
      yystate_ = yystate_stack_[0];
      YY_STACK_PRINT ();
    }

  if (yyn_ == yyfinal_)
    goto yyacceptlab;

  yyerror_range_[1] = yylloc;
  // Using YYLLOC is tempting, but would change the location of
  // the look-ahead.  YYLOC is available though.
  YYLLOC_DEFAULT (yyloc, yyerror_range_ - 1, 2);
  yysemantic_stack_.push (yylval);
  yylocation_stack_.push (yyloc);

  /* Shift the error token. */
  YY_SYMBOL_PRINT ("Shifting", yystos_[yyn_],
		   &yysemantic_stack_[0], &yylocation_stack_[0]);

  yystate_ = yyn_;
  goto yynewstate;

  /* Accept.  */
yyacceptlab:
  return 0;

  /* Abort.  */
yyabortlab:
  /* Free the lookahead. */
  yydestruct_ ("Error: discarding lookahead", yyilooka_, &yylval, &yylloc);
  yylooka_ = yyempty_;
  return 1;
}

void
yy::]b4_parser_class_name[::yylex_ ()
{
  YYCDEBUG << "Reading a token: ";
#if YYLSP_NEEDED
  yylooka_ = yylex (&yylval, &yylloc);
#else
  yylooka_ = yylex (&yylval);
#endif
}

// Generate an error message, and invoke error.
void
yy::]b4_parser_class_name[::yyreport_syntax_error_ ()
{
  /* If not already recovering from an error, report this error.  */
  if (!yyerrstatus_)
    {
      ++yynerrs_;
      std::string message;
#if YYERROR_VERBOSE
      yyn_ = yypact_[yystate_];
      if (yypact_ninf_ < yyn_ && yyn_ < yylast_)
	{
	  /* Start YYX at -YYN if negative to avoid negative indexes in
	     YYCHECK.  */
	  int yyxbegin = yyn_ < 0 ? -yyn_ : 0;

	  /* Stay within bounds of both yycheck and yytname.  */
	  int yychecklim = yylast_ - yyn_;
	  int yyxend = yychecklim < yyntokens_ ? yychecklim : yyntokens_;
          int count = 0;
          for (int x = yyxbegin; x < yyxend; ++x)
            if (yycheck_[x + yyn_] == x && x != yyterror_)
              ++count;

	  message = "syntax error, unexpected ";
	  message += yyname_[yyilooka_];
          if (count < 5)
            {
              count = 0;
              for (int x = yyxbegin; x < yyxend; ++x)
                if (yycheck_[x + yyn_] == x && x != yyterror_)
                  {
                    message += (!count++) ? ", expecting " : " or ";
                    message += yyname_[x];
 	          }
            }
	}
      else
#endif
	message = "syntax error";
      error (yylloc, message);
    }
}


/* YYPACT[STATE-NUM] -- Index in YYTABLE of the portion describing
   STATE-NUM.  */
const ]b4_int_type(b4_pact_ninf, b4_pact_ninf) yy::b4_parser_class_name::yypact_ninf_ = b4_pact_ninf[;
const ]b4_int_type_for([b4_pact])[
yy::]b4_parser_class_name[::yypact_[] =
{
  ]b4_pact[
};

/* YYDEFACT[S] -- default rule to reduce with in state S when YYTABLE
   doesn't specify something else to do.  Zero means the default is an
   error.  */
const ]b4_int_type_for([b4_defact])[
yy::]b4_parser_class_name[::yydefact_[] =
{
  ]b4_defact[
};

/* YYPGOTO[NTERM-NUM].  */
const ]b4_int_type_for([b4_pgoto])[
yy::]b4_parser_class_name[::yypgoto_[] =
{
  ]b4_pgoto[
};

/* YYDEFGOTO[NTERM-NUM].  */
const ]b4_int_type_for([b4_defgoto])[
yy::]b4_parser_class_name[::yydefgoto_[] =
{
  ]b4_defgoto[
};

/* YYTABLE[YYPACT[STATE-NUM]].  What to do in state STATE-NUM.  If
   positive, shift that token.  If negative, reduce the rule which
   number is the opposite.  If zero, do what YYDEFACT says.  */
const ]b4_int_type(b4_table_ninf, b4_table_ninf) yy::b4_parser_class_name::yytable_ninf_ = b4_table_ninf[;