lex.c

gcc-2.95.3 Linux下最常用的C编译器

      return (unicode_t)0x9;
    case 'n':
      return (unicode_t)0xa;
    case 'f':
      return (unicode_t)0xc;
    case 'r':
      return (unicode_t)0xd;
    case '"':
      return (unicode_t)0x22;
    case '\'':
      return (unicode_t)0x27;
    case '\\':
      return (unicode_t)0x5c;
    case '0': case '1': case '2': case '3': case '4':
    case '5': case '6': case '7': case '8': case '9':
      {
	int octal_escape[3];
	int octal_escape_index = 0;
	
	for (; octal_escape_index < 3 && RANGE (c, '0', '9');
	     c = java_get_unicode ())
	  octal_escape [octal_escape_index++] = c;

	java_unget_unicode ();

	if ((octal_escape_index == 3) && (octal_escape [0] > '3'))
	  {
	    java_lex_error ("Literal octal escape out of range", 0);
	    return JAVA_CHAR_ERROR;
	  }
	else
	  {
	    int i, shift;
	    for (char_lit=0, i = 0, shift = 3*(octal_escape_index-1);
		 i < octal_escape_index; i++, shift -= 3)
	      char_lit |= (octal_escape [i] - '0') << shift;

	    return (char_lit);
	  }
	break;
      }
    case '\n':
      return '\n';		/* ULT, caught latter as a specific error */
    default:
      java_lex_error ("Illegal character in escape sequence", 0);
      return JAVA_CHAR_ERROR;
    }
}

int
#ifdef JC1_LITE
yylex (java_lval)
#else
java_lex (java_lval)
#endif
     YYSTYPE *java_lval;
{
  unicode_t c, first_unicode;
  int ascii_index, all_ascii;
  char *string;

  /* Translation of the Unicode escape in the raw stream of Unicode
     characters. Takes care of line terminator.  */
 step1:
  /* Skip white spaces: SP, TAB and FF or ULT */ 
  for (c = java_get_unicode ();
       c == '\n' || JAVA_WHITE_SPACE_P (c); c = java_get_unicode ())
    if (c == '\n')
      {
	ctxp->elc.line = ctxp->c_line->lineno;
	ctxp->elc.col  = ctxp->c_line->char_col-2;
      }

  ctxp->elc.col = (ctxp->elc.col < 0 ? 0 : ctxp->elc.col);

  if (c == 0x1a)		/* CTRL-Z */
    {
      if ((c = java_get_unicode ()) == UEOF)
	return 0;		/* Ok here */
      else
	java_unget_unicode ();	/* Caught latter at the end the function */
    }
  /* Handle EOF here */
  if (c == UEOF)	/* Should probably do something here... */
    return 0;

  /* Take care of eventual comments.  */
  if (c == '/')
    {
      switch (c = java_get_unicode ())
	{
	case '/':
	  for (;;)
	    {
	      c = java_get_unicode ();
	      if (c == UEOF)
		java_lex_error ("Comment not terminated at end of input", 0);
	      if (c == '\n')	/* ULT */
		goto step1;
	    }
	  break;

	case '*':
	  if ((c = java_get_unicode ()) == '*')
	    {
	      if ((c = java_get_unicode ()) == '/')
		goto step1;	/* Empy documentation comment  */
	      else if (java_parse_doc_section (c))
		goto step1;
	    }

	  java_parse_end_comment (c);
	  goto step1;
	  break;
	default:
	  java_unget_unicode ();
	  c = '/';
	  break;
	}
    }

  ctxp->elc.line = ctxp->c_line->lineno;
  ctxp->elc.prev_col = ctxp->elc.col;
  ctxp->elc.col = ctxp->c_line->char_col - JAVA_COLUMN_DELTA (-1);
  if (ctxp->elc.col < 0)
    fatal ("ctxp->elc.col < 0 - java_lex");

  /* Numeric literals */
  if (JAVA_ASCII_DIGIT (c) || (c == '.'))
    {
      /* This section of code is borrowed from gcc/c-lex.c  */
#define TOTAL_PARTS ((HOST_BITS_PER_WIDE_INT / HOST_BITS_PER_CHAR) * 2 + 2)
      int parts[TOTAL_PARTS];
      HOST_WIDE_INT high, low;
      /* End borrowed section  */
      char literal_token [256];
      int  literal_index = 0, radix = 10, long_suffix = 0, overflow = 0, bytes;
      int  i;
#ifndef JC1_LITE
      int  number_beginning = ctxp->c_line->current;
#endif
      
      /* We might have a . separator instead of a FP like .[0-9]* */
      if (c == '.')
	{
	  unicode_t peep = java_sneak_unicode ();

	  if (!JAVA_ASCII_DIGIT (peep))
	    {
	      JAVA_LEX_SEP('.');
	      BUILD_OPERATOR (DOT_TK);
	    }
	}

      for (i = 0; i < TOTAL_PARTS; i++)
	parts [i] = 0;

      if (c == '0')
	{
	  c = java_get_unicode ();
	  if (c == 'x' || c == 'X')
	    {
	      radix = 16;
	      c = java_get_unicode ();
	    }
	  else if (JAVA_ASCII_DIGIT (c))
	    radix = 8;
	  else if (c == '.')
	    {
	      /* Push the '.' back and prepare for a FP parsing... */
	      java_unget_unicode ();
	      c = '0';
	    }
	  else
	    {
	      /* We have a zero literal: 0, 0{f,F}, 0{d,D} */
	      JAVA_LEX_LIT ("0", 10);
              switch (c)
		{		
		case 'L': case 'l':
		  SET_LVAL_NODE (long_zero_node);
		  return (INT_LIT_TK);
		case 'f': case 'F':
		  SET_LVAL_NODE (float_zero_node);
		  return (FP_LIT_TK);
		case 'd': case 'D':
		  SET_LVAL_NODE (double_zero_node);
		  return (FP_LIT_TK);
		default:
		  java_unget_unicode ();
		  SET_LVAL_NODE (integer_zero_node);
		  return (INT_LIT_TK);
		}
	    }
	}
      /* Parse the first part of the literal, until we find something
	 which is not a number.  */
      while ((radix == 10 && JAVA_ASCII_DIGIT (c)) ||
	     (radix == 16 && JAVA_ASCII_HEXDIGIT (c)) ||
	     (radix == 8  && JAVA_ASCII_OCTDIGIT (c)))
	{
	  /* We store in a string (in case it turns out to be a FP) and in
	     PARTS if we have to process a integer literal.  */
	  int numeric = (RANGE (c, '0', '9') ? c-'0' : 10 +(c|0x20)-'a');
	  int count;

	  literal_token [literal_index++] = c;
	  /* This section of code if borrowed from gcc/c-lex.c  */
	  for (count = 0; count < TOTAL_PARTS; count++)
	    {
	      parts[count] *= radix;
	      if (count)
		{
		  parts[count]   += (parts[count-1] >> HOST_BITS_PER_CHAR);
		  parts[count-1] &= (1 << HOST_BITS_PER_CHAR) - 1;
		}
	      else
		parts[0] += numeric;
	    }
	  if (parts [TOTAL_PARTS-1] != 0)
	    overflow = 1;
	  /* End borrowed section.  */
	  c = java_get_unicode ();
	}

      /* If we have something from the FP char set but not a digit, parse
	 a FP literal.  */
      if (JAVA_ASCII_FPCHAR (c) && !JAVA_ASCII_DIGIT (c))
	{
	  int stage = 0;
	  int seen_digit = (literal_index ? 1 : 0);
	  int seen_exponent = 0;
	  int fflag = 0;	/* 1 for {f,F}, 0 for {d,D}. FP literal are
				   double unless specified. */
	  if (radix != 10)
	    java_lex_error ("Can't express non-decimal FP literal", 0);

	  for (;;)
	    {
	      if (c == '.')
		{
		  if (stage < 1)
		    {
		      stage = 1;
		      literal_token [literal_index++ ] = c;
		      c = java_get_unicode ();
		    }
		  else
		    java_lex_error ("Invalid character in FP literal", 0);
		}

	      if (c == 'e' || c == 'E')
		{
		  if (stage < 2)
		    {
		      /* {E,e} must have seen at list a digit */
		      if (!seen_digit)
			java_lex_error ("Invalid FP literal", 0);
		      seen_digit = 0;
		      seen_exponent = 1;
		      stage = 2;
		      literal_token [literal_index++] = c;
		      c = java_get_unicode ();
		    }
		  else
		    java_lex_error ("Invalid character in FP literal", 0);
		}
	      if ( c == 'f' || c == 'F' || c == 'd' || c == 'D')
		{
		  fflag = ((c == 'd') || (c == 'D')) ? 0 : 1;
		  stage = 4;	/* So we fall through */
		}

	      if ((c=='-' || c =='+') && stage == 2)
		{
		  stage = 3;
		  literal_token [literal_index++] = c;
		  c = java_get_unicode ();
		}

	      if ((stage == 0 && JAVA_ASCII_FPCHAR (c)) ||
		  (stage == 1 && JAVA_ASCII_FPCHAR (c) && !(c == '.')) ||
		  (stage == 2 && (JAVA_ASCII_DIGIT (c) || JAVA_FP_PM (c))) ||
		  (stage == 3 && JAVA_ASCII_DIGIT (c)))
		{
		  if (JAVA_ASCII_DIGIT (c))
		    seen_digit = 1;
		  literal_token [literal_index++ ] = c;
		  c = java_get_unicode ();
		}
	      else
		{
		  jmp_buf handler;
		  REAL_VALUE_TYPE value;
#ifndef JC1_LITE
		  tree type = (fflag ? FLOAT_TYPE_NODE : DOUBLE_TYPE_NODE);
#endif

		  if (stage != 4) /* Don't push back fF/dD */
		    java_unget_unicode ();
		  
		  /* An exponent (if any) must have seen a digit.  */
		  if (seen_exponent && !seen_digit)
		    java_lex_error ("Invalid FP literal", 0);

		  literal_token [literal_index] = '\0';
		  JAVA_LEX_LIT (literal_token, radix);

		  if (setjmp (handler))
		    {
		      JAVA_FLOAT_RANGE_ERROR ((fflag ? "float" : "double"));
		      value = DCONST0;
		    }
		  else
		    {
		      SET_FLOAT_HANDLER (handler);
		      SET_REAL_VALUE_ATOF 
		        (value, REAL_VALUE_ATOF (literal_token, 
						 TYPE_MODE (type)));

		      if (REAL_VALUE_ISINF (value))
			JAVA_FLOAT_RANGE_ERROR ((fflag ? "float" : "double"));

		      if (REAL_VALUE_ISNAN (value))
			JAVA_FLOAT_RANGE_ERROR ((fflag ? "float" : "double"));

		      SET_LVAL_NODE_TYPE (build_real (type, value), type);
		      SET_FLOAT_HANDLER (NULL_PTR);
		      return FP_LIT_TK;
		    }
		}
	    }
	} /* JAVA_ASCCI_FPCHAR (c) */

      /* Here we get back to converting the integral literal.  */
      if (c == 'L' || c == 'l')
	long_suffix = 1;
      else if (radix == 16 && JAVA_ASCII_LETTER (c))
	java_lex_error ("Digit out of range in hexadecimal literal", 0);
      else if (radix == 8  && JAVA_ASCII_DIGIT (c))
	java_lex_error ("Digit out of range in octal literal", 0);
      else if (radix == 16 && !literal_index)
	java_lex_error ("No digit specified for hexadecimal literal", 0);
      else
	java_unget_unicode ();

#ifdef JAVA_LEX_DEBUG
      literal_token [literal_index] = '\0'; /* So JAVA_LEX_LIT is safe. */
      JAVA_LEX_LIT (literal_token, radix);
#endif
      /* This section of code is borrowed from gcc/c-lex.c  */
      if (!overflow)
	{
	  bytes = GET_TYPE_PRECISION (long_type_node);
	  for (i = bytes; i < TOTAL_PARTS; i++)
	    if (parts [i])
	      {
	        overflow = 1;
		break;
	      }
	}
      high = low = 0;
      for (i = 0; i < HOST_BITS_PER_WIDE_INT / HOST_BITS_PER_CHAR; i++)
	{
	  high |= ((HOST_WIDE_INT) parts[i + (HOST_BITS_PER_WIDE_INT
					      / HOST_BITS_PER_CHAR)]
		   << (i * HOST_BITS_PER_CHAR));
	  low |= (HOST_WIDE_INT) parts[i] << (i * HOST_BITS_PER_CHAR);
	}
      /* End borrowed section.  */

      /* Range checking */
      if (long_suffix)
	{
	  /* 9223372036854775808L is valid if operand of a '-'. Otherwise
	     9223372036854775807L is the biggest `long' literal that can be
	     expressed using a 10 radix. For other radixes, everything that
	     fits withing 64 bits is OK. */
	  int hb = (high >> 31);
	  if (overflow || (hb && low && radix == 10) ||  
	      (hb && high & 0x7fffffff && radix == 10) ||
	      (hb && !(high & 0x7fffffff) && !ctxp->minus_seen && radix == 10))
	    JAVA_INTEGRAL_RANGE_ERROR ("Numeric overflow for `long' literal");
	}
      else
	{
	  /* 2147483648 is valid if operand of a '-'. Otherwise,
	     2147483647 is the biggest `int' literal that can be
	     expressed using a 10 radix. For other radixes, everything
	     that fits within 32 bits is OK.  As all literals are
	     signed, we sign extend here. */
	  int hb = (low >> 31) & 0x1;
	  if (overflow || high || (hb && low & 0x7fffffff && radix == 10) ||
	      (hb && !(low & 0x7fffffff) && !ctxp->minus_seen && radix == 10))
	    JAVA_INTEGRAL_RANGE_ERROR ("Numeric overflow for `int' literal");
	  high = -hb;
	}
      ctxp->minus_seen = 0;
      SET_LVAL_NODE_TYPE (build_int_2 (low, high),
			  (long_suffix ? long_type_node : int_type_node));
      return INT_LIT_TK;
    }

  ctxp->minus_seen = 0;
  /* Character literals */
  if (c == '\'')
    {
      unicode_t char_lit;
      if ((c = java_get_unicode ()) == '\\')
	char_lit = java_parse_escape_sequence ();
      else
	char_lit = c;

      c = java_get_unicode ();
      
      if ((c == '\n') || (c == UEOF))
	java_lex_error ("Character literal not terminated at end of line", 0);
      if (c != '\'')
	java_lex_error ("Syntax error in character literal", 0);

      if (c == JAVA_CHAR_ERROR)
        char_lit = 0;		/* We silently convert it to zero */

      JAVA_LEX_CHAR_LIT (char_lit);
      SET_LVAL_NODE_TYPE (build_int_2 (char_lit, 0), char_type_node);
      return CHAR_LIT_TK;
    }

  /* String literals */
  if (c == '"')
    {
      int no_error;
      char *string;

      for (no_error = 1, c = java_get_unicode (); 
	   c != '"' && c != '\n'; c = java_get_unicode ())
	{
	  if (c == '\\')
	    c = java_parse_escape_sequence ();
	  no_error &= (c != JAVA_CHAR_ERROR ? 1 : 0);
	  java_unicode_2_utf8 (c);
	}
      if (c == '\n' || c == UEOF) /* ULT */
	{
	  lineno--;		/* Refer to the line the terminator was seen */
	  java_lex_error ("String not terminated at end of line.", 0);
	  lineno++;
	}

      obstack_1grow (&temporary_obstack, '\0');
      string = obstack_finish (&temporary_obstack);
#ifndef JC1_LITE
      if (!no_error || (c != '"'))
	java_lval->node = error_mark_node; /* Requires futher testing FIXME */
      else
	{
	  tree s = make_node (STRING_CST);
	  TREE_STRING_LENGTH (s) = strlen (string);
	  TREE_STRING_POINTER (s) = 
	    obstack_alloc (expression_obstack, TREE_STRING_LENGTH (s)+1);
	  strcpy (TREE_STRING_POINTER (s), string);
	  java_lval->node = s;
	}
#endif
      return STRING_LIT_TK;
    }

  /* Separator */
  switch (c)
    {