analysis.c

大学操作系统课程实验：Linux下实现的一个shell解释器。能够比较完整完好地执行Linux下的普通命令、重定向命令、管道命令等多种命令。

/* YYR2[YYN] -- Number of symbols composing right hand side of rule YYN.  */
static const yytype_uint8 yyr2[] =
{
       0,     2,     0,     1,     2,     1,     3,     3,     2,     0,
       3,     3,     2,     0,     2,     0,     2,     1,     0,     2
};

/* YYDEFACT[STATE-NAME] -- Default rule to reduce with in state
   STATE-NUM when YYTABLE doesn't specify something else to do.  Zero
   means the default is an error.  */
static const yytype_uint8 yydefact[] =
{
       2,    17,     0,     3,     5,     9,    13,    18,     1,     4,
       0,     0,    15,    12,     0,     6,    14,     0,     7,    19,
      15,    16,    11
};

/* YYDEFGOTO[NTERM-NUM].  */
static const yytype_int8 yydefgoto[] =
{
      -1,     2,     3,     4,     5,    10,    15,     6,    12,    18,
       7,    13
};

/* YYPACT[STATE-NUM] -- Index in YYTABLE of the portion describing
   STATE-NUM.  */
#define YYPACT_NINF -8
static const yytype_int8 yypact[] =
{
       1,    -8,     5,     2,    -8,    -8,     3,    -8,    -8,    -8,
       6,     4,    -5,     7,     1,    -8,    -8,     9,    -8,    -8,
      -4,    -8,    -8
};

/* YYPGOTO[NTERM-NUM].  */
static const yytype_int8 yypgoto[] =
{
      -8,    -8,    -8,    -8,    -8,    -8,    -8,    -6,    -8,    -7,
      -8,    -8
};

/* 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.
   If YYTABLE_NINF, syntax error.  */
#define YYTABLE_NINF -11
static const yytype_int8 yytable[] =
{
      -8,   -10,    17,    17,     1,     8,     9,    16,    20,    11,
      19,    14,    21,    22
};

static const yytype_uint8 yycheck[] =
{
       5,     5,     7,     7,     3,     0,     4,     3,    14,     6,
       3,     5,     3,    20
};

/* YYSTOS[STATE-NUM] -- The (internal number of the) accessing
   symbol of state STATE-NUM.  */
static const yytype_uint8 yystos[] =
{
       0,     3,     9,    10,    11,    12,    15,    18,     0,     4,
      13,     6,    16,    19,     5,    14,     3,     7,    17,     3,
      15,     3,    17
};

#define yyerrok		(yyerrstatus = 0)
#define yyclearin	(yychar = YYEMPTY)
#define YYEMPTY		(-2)
#define YYEOF		0

#define YYACCEPT	goto yyacceptlab
#define YYABORT		goto yyabortlab
#define YYERROR		goto yyerrorlab


/* Like YYERROR except do call yyerror.  This remains here temporarily
   to ease the transition to the new meaning of YYERROR, for GCC.
   Once GCC version 2 has supplanted version 1, this can go.  */

#define YYFAIL		goto yyerrlab

#define YYRECOVERING()  (!!yyerrstatus)

#define YYBACKUP(Token, Value)					\
do								\
  if (yychar == YYEMPTY && yylen == 1)				\
    {								\
      yychar = (Token);						\
      yylval = (Value);						\
      yytoken = YYTRANSLATE (yychar);				\
      YYPOPSTACK (1);						\
      goto yybackup;						\
    }								\
  else								\
    {								\
      yyerror (YY_("syntax error: cannot back up")); \
      YYERROR;							\
    }								\
while (YYID (0))


#define YYTERROR	1
#define YYERRCODE	256


/* YYLLOC_DEFAULT -- Set CURRENT to span from RHS[1] to RHS[N].
   If N is 0, then set CURRENT to the empty location which ends
   the previous symbol: RHS[0] (always defined).  */

#define YYRHSLOC(Rhs, K) ((Rhs)[K])
#ifndef YYLLOC_DEFAULT
# define YYLLOC_DEFAULT(Current, Rhs, N)				\
    do									\
      if (YYID (N))                                                    \
	{								\
	  (Current).first_line   = YYRHSLOC (Rhs, 1).first_line;	\
	  (Current).first_column = YYRHSLOC (Rhs, 1).first_column;	\
	  (Current).last_line    = YYRHSLOC (Rhs, N).last_line;		\
	  (Current).last_column  = YYRHSLOC (Rhs, N).last_column;	\
	}								\
      else								\
	{								\
	  (Current).first_line   = (Current).last_line   =		\
	    YYRHSLOC (Rhs, 0).last_line;				\
	  (Current).first_column = (Current).last_column =		\
	    YYRHSLOC (Rhs, 0).last_column;				\
	}								\
    while (YYID (0))
#endif


/* YY_LOCATION_PRINT -- Print the location on the stream.
   This macro was not mandated originally: define only if we know
   we won't break user code: when these are the locations we know.  */

#ifndef YY_LOCATION_PRINT
# if YYLTYPE_IS_TRIVIAL
#  define YY_LOCATION_PRINT(File, Loc)			\
     fprintf (File, "%d.%d-%d.%d",			\
	      (Loc).first_line, (Loc).first_column,	\
	      (Loc).last_line,  (Loc).last_column)
# else
#  define YY_LOCATION_PRINT(File, Loc) ((void) 0)
# endif
#endif


/* YYLEX -- calling `yylex' with the right arguments.  */

#ifdef YYLEX_PARAM
# define YYLEX yylex (YYLEX_PARAM)
#else
# define YYLEX yylex ()
#endif

/* Enable debugging if requested.  */
#if YYDEBUG

# ifndef YYFPRINTF
#  include <stdio.h> /* INFRINGES ON USER NAME SPACE */
#  define YYFPRINTF fprintf
# endif

# define YYDPRINTF(Args)			\
do {						\
  if (yydebug)					\
    YYFPRINTF Args;				\
} while (YYID (0))

# define YY_SYMBOL_PRINT(Title, Type, Value, Location)			  \
do {									  \
  if (yydebug)								  \
    {									  \
      YYFPRINTF (stderr, "%s ", Title);					  \
      yy_symbol_print (stderr,						  \
		  Type, Value); \
      YYFPRINTF (stderr, "\n");						  \
    }									  \
} while (YYID (0))


/*--------------------------------.
| Print this symbol on YYOUTPUT.  |
`--------------------------------*/

/*ARGSUSED*/
#if (defined __STDC__ || defined __C99__FUNC__ \
     || defined __cplusplus || defined _MSC_VER)
static void
yy_symbol_value_print (FILE *yyoutput, int yytype, YYSTYPE const * const yyvaluep)
#else
static void
yy_symbol_value_print (yyoutput, yytype, yyvaluep)
    FILE *yyoutput;
    int yytype;
    YYSTYPE const * const yyvaluep;
#endif
{
  if (!yyvaluep)
    return;
# ifdef YYPRINT
  if (yytype < YYNTOKENS)
    YYPRINT (yyoutput, yytoknum[yytype], *yyvaluep);
# else
  YYUSE (yyoutput);
# endif
  switch (yytype)
    {
      default:
	break;
    }
}


/*--------------------------------.
| Print this symbol on YYOUTPUT.  |
`--------------------------------*/

#if (defined __STDC__ || defined __C99__FUNC__ \
     || defined __cplusplus || defined _MSC_VER)
static void
yy_symbol_print (FILE *yyoutput, int yytype, YYSTYPE const * const yyvaluep)
#else
static void
yy_symbol_print (yyoutput, yytype, yyvaluep)
    FILE *yyoutput;
    int yytype;
    YYSTYPE const * const yyvaluep;
#endif
{
  if (yytype < YYNTOKENS)
    YYFPRINTF (yyoutput, "token %s (", yytname[yytype]);
  else
    YYFPRINTF (yyoutput, "nterm %s (", yytname[yytype]);

  yy_symbol_value_print (yyoutput, yytype, yyvaluep);
  YYFPRINTF (yyoutput, ")");
}

/*------------------------------------------------------------------.
| yy_stack_print -- Print the state stack from its BOTTOM up to its |
| TOP (included).                                                   |
`------------------------------------------------------------------*/

#if (defined __STDC__ || defined __C99__FUNC__ \
     || defined __cplusplus || defined _MSC_VER)
static void
yy_stack_print (yytype_int16 *bottom, yytype_int16 *top)
#else
static void
yy_stack_print (bottom, top)
    yytype_int16 *bottom;
    yytype_int16 *top;
#endif
{
  YYFPRINTF (stderr, "Stack now");
  for (; bottom <= top; ++bottom)
    YYFPRINTF (stderr, " %d", *bottom);
  YYFPRINTF (stderr, "\n");
}

# define YY_STACK_PRINT(Bottom, Top)				\
do {								\
  if (yydebug)							\
    yy_stack_print ((Bottom), (Top));				\
} while (YYID (0))


/*------------------------------------------------.
| Report that the YYRULE is going to be reduced.  |
`------------------------------------------------*/

#if (defined __STDC__ || defined __C99__FUNC__ \
     || defined __cplusplus || defined _MSC_VER)
static void
yy_reduce_print (YYSTYPE *yyvsp, int yyrule)
#else
static void
yy_reduce_print (yyvsp, yyrule)
    YYSTYPE *yyvsp;
    int yyrule;
#endif
{
  int yynrhs = yyr2[yyrule];
  int yyi;
  unsigned long int yylno = yyrline[yyrule];
  YYFPRINTF (stderr, "Reducing stack by rule %d (line %lu):\n",
	     yyrule - 1, yylno);
  /* The symbols being reduced.  */
  for (yyi = 0; yyi < yynrhs; yyi++)
    {
      fprintf (stderr, "   $%d = ", yyi + 1);
      yy_symbol_print (stderr, yyrhs[yyprhs[yyrule] + yyi],
		       &(yyvsp[(yyi + 1) - (yynrhs)])
		       		       );
      fprintf (stderr, "\n");
    }
}

# define YY_REDUCE_PRINT(Rule)		\
do {					\
  if (yydebug)				\
    yy_reduce_print (yyvsp, Rule); \
} while (YYID (0))

/* Nonzero means print parse trace.  It is left uninitialized so that
   multiple parsers can coexist.  */
int yydebug;
#else /* !YYDEBUG */
# define YYDPRINTF(Args)
# define YY_SYMBOL_PRINT(Title, Type, Value, Location)
# define YY_STACK_PRINT(Bottom, Top)
# define YY_REDUCE_PRINT(Rule)
#endif /* !YYDEBUG */


/* YYINITDEPTH -- initial size of the parser's stacks.  */
#ifndef	YYINITDEPTH
# define YYINITDEPTH 200
#endif

/* YYMAXDEPTH -- maximum size the stacks can grow to (effective only
   if the built-in stack extension method is used).

   Do not make this value too large; the results are undefined if
   YYSTACK_ALLOC_MAXIMUM < YYSTACK_BYTES (YYMAXDEPTH)
   evaluated with infinite-precision integer arithmetic.  */

#ifndef YYMAXDEPTH
# define YYMAXDEPTH 10000
#endif



#if YYERROR_VERBOSE

# ifndef yystrlen
#  if defined __GLIBC__ && defined _STRING_H
#   define yystrlen strlen
#  else
/* Return the length of YYSTR.  */
#if (defined __STDC__ || defined __C99__FUNC__ \
     || defined __cplusplus || defined _MSC_VER)
static YYSIZE_T
yystrlen (const char *yystr)
#else
static YYSIZE_T
yystrlen (yystr)
    const char *yystr;
#endif
{
  YYSIZE_T yylen;
  for (yylen = 0; yystr[yylen]; yylen++)
    continue;
  return yylen;
}
#  endif
# endif

# ifndef yystpcpy
#  if defined __GLIBC__ && defined _STRING_H && defined _GNU_SOURCE
#   define yystpcpy stpcpy
#  else
/* Copy YYSRC to YYDEST, returning the address of the terminating '\0' in
   YYDEST.  */
#if (defined __STDC__ || defined __C99__FUNC__ \
     || defined __cplusplus || defined _MSC_VER)
static char *
yystpcpy (char *yydest, const char *yysrc)
#else
static char *
yystpcpy (yydest, yysrc)
    char *yydest;
    const char *yysrc;
#endif
{
  char *yyd = yydest;
  const char *yys = yysrc;

  while ((*yyd++ = *yys++) != '\0')
    continue;

  return yyd - 1;
}
#  endif
# endif

# ifndef yytnamerr
/* Copy to YYRES the contents of YYSTR after stripping away unnecessary
   quotes and backslashes, so that it's suitable for yyerror.  The
   heuristic is that double-quoting is unnecessary unless the string
   contains an apostrophe, a comma, or backslash (other than
   backslash-backslash).  YYSTR is taken from yytname.  If YYRES is
   null, do not copy; instead, return the length of what the result
   would have been.  */
static YYSIZE_T
yytnamerr (char *yyres, const char *yystr)
{
  if (*yystr == '"')
    {
      YYSIZE_T yyn = 0;
      char const *yyp = yystr;

      for (;;)
	switch (*++yyp)
	  {
	  case '\'':
	  case ',':
	    goto do_not_strip_quotes;

	  case '\\':
	    if (*++yyp != '\\')
	      goto do_not_strip_quotes;
	    /* Fall through.  */
	  default:
	    if (yyres)
	      yyres[yyn] = *yyp;
	    yyn++;
	    break;

	  case '"':
	    if (yyres)
	      yyres[yyn] = '\0';
	    return yyn;
	  }
    do_not_strip_quotes: ;
    }

  if (! yyres)
    return yystrlen (yystr);

  return yystpcpy (yyres, yystr) - yyres;
}
# endif

/* Copy into YYRESULT an error message about the unexpected token
   YYCHAR while in state YYSTATE.  Return the number of bytes copied,
   including the terminating null byte.  If YYRESULT is null, do not
   copy anything; just return the number of bytes that would be
   copied.  As a special case, return 0 if an ordinary "syntax error"
   message will do.  Return YYSIZE_MAXIMUM if overflow occurs during
   size calculation.  */
static YYSIZE_T
yysyntax_error (char *yyresult, int yystate, int yychar)