expr.c 61.8 KB
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/* Parse C expressions for cpplib.
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   Copyright (C) 1987-2018 Free Software Foundation, Inc.
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   Contributed by Per Bothner, 1994.
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This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
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Free Software Foundation; either version 3, or (at your option) any
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later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
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along with this program; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */
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#include "config.h"
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#include "system.h"
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#include "cpplib.h"
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#include "internal.h"
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#define PART_PRECISION (sizeof (cpp_num_part) * CHAR_BIT)
#define HALF_MASK (~(cpp_num_part) 0 >> (PART_PRECISION / 2))
#define LOW_PART(num_part) (num_part & HALF_MASK)
#define HIGH_PART(num_part) (num_part >> (PART_PRECISION / 2))

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struct op
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{
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  const cpp_token *token;	/* The token forming op (for diagnostics).  */
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  cpp_num value;		/* The value logically "right" of op.  */
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  source_location loc;          /* The location of this value.         */
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  enum cpp_ttype op;
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};

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/* Some simple utility routines on double integers.  */
#define num_zerop(num) ((num.low | num.high) == 0)
#define num_eq(num1, num2) (num1.low == num2.low && num1.high == num2.high)
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static bool num_positive (cpp_num, size_t);
static bool num_greater_eq (cpp_num, cpp_num, size_t);
static cpp_num num_trim (cpp_num, size_t);
static cpp_num num_part_mul (cpp_num_part, cpp_num_part);

static cpp_num num_unary_op (cpp_reader *, cpp_num, enum cpp_ttype);
static cpp_num num_binary_op (cpp_reader *, cpp_num, cpp_num, enum cpp_ttype);
static cpp_num num_negate (cpp_num, size_t);
static cpp_num num_bitwise_op (cpp_reader *, cpp_num, cpp_num, enum cpp_ttype);
static cpp_num num_inequality_op (cpp_reader *, cpp_num, cpp_num,
				  enum cpp_ttype);
static cpp_num num_equality_op (cpp_reader *, cpp_num, cpp_num,
				enum cpp_ttype);
static cpp_num num_mul (cpp_reader *, cpp_num, cpp_num);
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static cpp_num num_div_op (cpp_reader *, cpp_num, cpp_num, enum cpp_ttype,
			   source_location);
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static cpp_num num_lshift (cpp_num, size_t, size_t);
static cpp_num num_rshift (cpp_num, size_t, size_t);

static cpp_num append_digit (cpp_num, int, int, size_t);
static cpp_num parse_defined (cpp_reader *);
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static cpp_num eval_token (cpp_reader *, const cpp_token *, source_location);
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static struct op *reduce (cpp_reader *, struct op *, enum cpp_ttype);
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static unsigned int interpret_float_suffix (cpp_reader *, const uchar *, size_t);
static unsigned int interpret_int_suffix (cpp_reader *, const uchar *, size_t);
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static void check_promotion (cpp_reader *, const struct op *);
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static cpp_num parse_has_include (cpp_reader *, enum include_type);

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/* Token type abuse to create unary plus and minus operators.  */
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#define CPP_UPLUS ((enum cpp_ttype) (CPP_LAST_CPP_OP + 1))
#define CPP_UMINUS ((enum cpp_ttype) (CPP_LAST_CPP_OP + 2))
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/* With -O2, gcc appears to produce nice code, moving the error
   message load and subsequent jump completely out of the main path.  */
#define SYNTAX_ERROR(msgid) \
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  do { cpp_error (pfile, CPP_DL_ERROR, msgid); goto syntax_error; } while(0)
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#define SYNTAX_ERROR2(msgid, arg) \
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  do { cpp_error (pfile, CPP_DL_ERROR, msgid, arg); goto syntax_error; } \
  while(0)
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#define SYNTAX_ERROR_AT(loc, msgid) \
  do { cpp_error_with_line (pfile, CPP_DL_ERROR, (loc), 0, msgid); goto syntax_error; } \
  while(0)
#define SYNTAX_ERROR2_AT(loc, msgid, arg)					\
  do { cpp_error_with_line (pfile, CPP_DL_ERROR, (loc), 0, msgid, arg); goto syntax_error; } \
  while(0)
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/* Subroutine of cpp_classify_number.  S points to a float suffix of
   length LEN, possibly zero.  Returns 0 for an invalid suffix, or a
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   flag vector (of CPP_N_* bits) describing the suffix.  */
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static unsigned int
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interpret_float_suffix (cpp_reader *pfile, const uchar *s, size_t len)
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{
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  size_t orig_len = len;
  const uchar *orig_s = s;
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  size_t flags;
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  size_t f, d, l, w, q, i, fn, fnx, fn_bits;
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  flags = 0;
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  f = d = l = w = q = i = fn = fnx = fn_bits = 0;

  /* The following decimal float suffixes, from TR 24732:2009 and TS
     18661-2:2015, are supported:

     df, DF - _Decimal32.
     dd, DD - _Decimal64.
     dl, DL - _Decimal128.

     The dN and DN suffixes for _DecimalN, and dNx and DNx for
     _DecimalNx, defined in TS 18661-3:2015, are not supported.

     Fixed-point suffixes, from TR 18037:2008, are supported.  They
     consist of three parts, in order:

     (i) An optional u or U, for unsigned types.

     (ii) An optional h or H, for short types, or l or L, for long
     types, or ll or LL, for long long types.  Use of ll or LL is a
     GNU extension.

     (iii) r or R, for _Fract types, or k or K, for _Accum types.

     Otherwise the suffix is for a binary or standard floating-point
     type.  Such a suffix, or the absence of a suffix, may be preceded
     or followed by i, I, j or J, to indicate an imaginary number with
     the corresponding complex type.  The following suffixes for
     binary or standard floating-point types are supported:

     f, F - float (ISO C and C++).
     l, L - long double (ISO C and C++).
     d, D - double, even with the FLOAT_CONST_DECIMAL64 pragma in
	    operation (from TR 24732:2009; the pragma and the suffix
	    are not included in TS 18661-2:2015).
     w, W - machine-specific type such as __float80 (GNU extension).
     q, Q - machine-specific type such as __float128 (GNU extension).
     fN, FN - _FloatN (TS 18661-3:2015).
     fNx, FNx - _FloatNx (TS 18661-3:2015).  */
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  /* Process decimal float suffixes, which are two letters starting
     with d or D.  Order and case are significant.  */
  if (len == 2 && (*s == 'd' || *s == 'D'))
    {
      bool uppercase = (*s == 'D');
      switch (s[1])
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      {
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      case 'f': return (!uppercase ? (CPP_N_DFLOAT | CPP_N_SMALL): 0); break;
      case 'F': return (uppercase ? (CPP_N_DFLOAT | CPP_N_SMALL) : 0); break;
      case 'd': return (!uppercase ? (CPP_N_DFLOAT | CPP_N_MEDIUM): 0); break;
      case 'D': return (uppercase ? (CPP_N_DFLOAT | CPP_N_MEDIUM) : 0); break;
      case 'l': return (!uppercase ? (CPP_N_DFLOAT | CPP_N_LARGE) : 0); break;
      case 'L': return (uppercase ? (CPP_N_DFLOAT | CPP_N_LARGE) : 0); break;
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      default:
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	/* Additional two-character suffixes beginning with D are not
	   for decimal float constants.  */
	break;
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      }
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    }
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  if (CPP_OPTION (pfile, ext_numeric_literals))
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    {
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      /* Recognize a fixed-point suffix.  */
      if (len != 0)
	switch (s[len-1])
	  {
	  case 'k': case 'K': flags = CPP_N_ACCUM; break;
	  case 'r': case 'R': flags = CPP_N_FRACT; break;
	  default: break;
	  }

      /* Continue processing a fixed-point suffix.  The suffix is case
	 insensitive except for ll or LL.  Order is significant.  */
      if (flags)
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	{
	  if (len == 1)
	    return flags;
	  len--;

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	  if (*s == 'u' || *s == 'U')
	    {
	      flags |= CPP_N_UNSIGNED;
	      if (len == 1)
		return flags;
	      len--;
	      s++;
            }

	  switch (*s)
	  {
	  case 'h': case 'H':
	    if (len == 1)
	      return flags |= CPP_N_SMALL;
	    break;
	  case 'l':
	    if (len == 1)
	      return flags |= CPP_N_MEDIUM;
	    if (len == 2 && s[1] == 'l')
	      return flags |= CPP_N_LARGE;
	    break;
	  case 'L':
	    if (len == 1)
	      return flags |= CPP_N_MEDIUM;
	    if (len == 2 && s[1] == 'L')
	      return flags |= CPP_N_LARGE;
	    break;
	  default:
	    break;
	  }
	  /* Anything left at this point is invalid.  */
	  return 0;
	}
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    }

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  /* In any remaining valid suffix, the case and order don't matter.  */
  while (len--)
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    {
      switch (s[0])
	{
	case 'f': case 'F':
	  f++;
	  if (len > 0
	      && !CPP_OPTION (pfile, cplusplus)
	      && s[1] >= '1'
	      && s[1] <= '9'
	      && fn_bits == 0)
	    {
	      f--;
	      while (len > 0
		     && s[1] >= '0'
		     && s[1] <= '9'
		     && fn_bits < CPP_FLOATN_MAX)
		{
		  fn_bits = fn_bits * 10 + (s[1] - '0');
		  len--;
		  s++;
		}
	      if (len > 0 && s[1] == 'x')
		{
		  fnx++;
		  len--;
		  s++;
		}
	      else
		fn++;
	    }
	  break;
	case 'd': case 'D': d++; break;
	case 'l': case 'L': l++; break;
	case 'w': case 'W': w++; break;
	case 'q': case 'Q': q++; break;
	case 'i': case 'I':
	case 'j': case 'J': i++; break;
	default:
	  return 0;
	}
      s++;
    }
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  /* Reject any case of multiple suffixes specifying types, multiple
     suffixes specifying an imaginary constant, _FloatN or _FloatNx
     suffixes for invalid values of N, and _FloatN suffixes for values
     of N larger than can be represented in the return value.  The
     caller is responsible for rejecting _FloatN suffixes where
     _FloatN is not supported on the chosen target.  */
  if (f + d + l + w + q + fn + fnx > 1 || i > 1)
    return 0;
  if (fn_bits > CPP_FLOATN_MAX)
    return 0;
  if (fnx && fn_bits != 32 && fn_bits != 64 && fn_bits != 128)
    return 0;
  if (fn && fn_bits != 16 && fn_bits % 32 != 0)
    return 0;
  if (fn && fn_bits == 96)
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    return 0;

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  if (i)
    {
      if (!CPP_OPTION (pfile, ext_numeric_literals))
	return 0;

      /* In C++14 and up these suffixes are in the standard library, so treat
	 them as user-defined literals.  */
      if (CPP_OPTION (pfile, cplusplus)
	  && CPP_OPTION (pfile, lang) > CLK_CXX11
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	  && orig_s[0] == 'i'
	  && (orig_len == 1
	      || (orig_len == 2
		  && (orig_s[1] == 'f' || orig_s[1] == 'l'))))
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	return 0;
    }
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  if ((w || q) && !CPP_OPTION (pfile, ext_numeric_literals))
    return 0;

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  return ((i ? CPP_N_IMAGINARY : 0)
	  | (f ? CPP_N_SMALL :
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	     d ? CPP_N_MEDIUM :
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	     l ? CPP_N_LARGE :
	     w ? CPP_N_MD_W :
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	     q ? CPP_N_MD_Q :
	     fn ? CPP_N_FLOATN | (fn_bits << CPP_FLOATN_SHIFT) :
	     fnx ? CPP_N_FLOATNX | (fn_bits << CPP_FLOATN_SHIFT) :
	     CPP_N_DEFAULT));
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}

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/* Return the classification flags for a float suffix.  */
unsigned int
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cpp_interpret_float_suffix (cpp_reader *pfile, const char *s, size_t len)
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{
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  return interpret_float_suffix (pfile, (const unsigned char *)s, len);
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}

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/* Subroutine of cpp_classify_number.  S points to an integer suffix
   of length LEN, possibly zero. Returns 0 for an invalid suffix, or a
   flag vector describing the suffix.  */
static unsigned int
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interpret_int_suffix (cpp_reader *pfile, const uchar *s, size_t len)
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{
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  size_t orig_len = len;
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  size_t u, l, i;

  u = l = i = 0;

  while (len--)
    switch (s[len])
      {
      case 'u': case 'U':	u++; break;
      case 'i': case 'I':
      case 'j': case 'J':	i++; break;
      case 'l': case 'L':	l++;
	/* If there are two Ls, they must be adjacent and the same case.  */
	if (l == 2 && s[len] != s[len + 1])
	  return 0;
	break;
      default:
	return 0;
      }

  if (l > 2 || u > 1 || i > 1)
    return 0;

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  if (i)
    {
      if (!CPP_OPTION (pfile, ext_numeric_literals))
	return 0;

      /* In C++14 and up these suffixes are in the standard library, so treat
	 them as user-defined literals.  */
      if (CPP_OPTION (pfile, cplusplus)
	  && CPP_OPTION (pfile, lang) > CLK_CXX11
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	  && s[0] == 'i'
	  && (orig_len == 1 || (orig_len == 2 && s[1] == 'l')))
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	return 0;
    }
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  return ((i ? CPP_N_IMAGINARY : 0)
	  | (u ? CPP_N_UNSIGNED : 0)
	  | ((l == 0) ? CPP_N_SMALL
	     : (l == 1) ? CPP_N_MEDIUM : CPP_N_LARGE));
}

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/* Return the classification flags for an int suffix.  */
unsigned int
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cpp_interpret_int_suffix (cpp_reader *pfile, const char *s, size_t len)
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{
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  return interpret_int_suffix (pfile, (const unsigned char *)s, len);
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}

/* Return the string type corresponding to the the input user-defined string
   literal type.  If the input type is not a user-defined string literal
   type return the input type.  */
enum cpp_ttype
cpp_userdef_string_remove_type (enum cpp_ttype type)
{
  if (type == CPP_STRING_USERDEF)
    return CPP_STRING;
  else if (type == CPP_WSTRING_USERDEF)
    return CPP_WSTRING;
  else if (type == CPP_STRING16_USERDEF)
    return CPP_STRING16;
  else if (type == CPP_STRING32_USERDEF)
    return CPP_STRING32;
  else if (type == CPP_UTF8STRING_USERDEF)
    return CPP_UTF8STRING;
  else
    return type;
}

/* Return the user-defined string literal type corresponding to the input
   string type.  If the input type is not a string type return the input
   type.  */
enum cpp_ttype
cpp_userdef_string_add_type (enum cpp_ttype type)
{
  if (type == CPP_STRING)
    return CPP_STRING_USERDEF;
  else if (type == CPP_WSTRING)
    return CPP_WSTRING_USERDEF;
  else if (type == CPP_STRING16)
    return CPP_STRING16_USERDEF;
  else if (type == CPP_STRING32)
    return CPP_STRING32_USERDEF;
  else if (type == CPP_UTF8STRING)
    return CPP_UTF8STRING_USERDEF;
  else
    return type;
}

/* Return the char type corresponding to the the input user-defined char
   literal type.  If the input type is not a user-defined char literal
   type return the input type.  */
enum cpp_ttype
cpp_userdef_char_remove_type (enum cpp_ttype type)
{
  if (type == CPP_CHAR_USERDEF)
    return CPP_CHAR;
  else if (type == CPP_WCHAR_USERDEF)
    return CPP_WCHAR;
  else if (type == CPP_CHAR16_USERDEF)
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    return CPP_CHAR16;
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  else if (type == CPP_CHAR32_USERDEF)
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    return CPP_CHAR32;
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  else if (type == CPP_UTF8CHAR_USERDEF)
    return CPP_UTF8CHAR;
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  else
    return type;
}

/* Return the user-defined char literal type corresponding to the input
   char type.  If the input type is not a char type return the input
   type.  */
enum cpp_ttype
cpp_userdef_char_add_type (enum cpp_ttype type)
{
  if (type == CPP_CHAR)
    return CPP_CHAR_USERDEF;
  else if (type == CPP_WCHAR)
    return CPP_WCHAR_USERDEF;
  else if (type == CPP_CHAR16)
    return CPP_CHAR16_USERDEF;
  else if (type == CPP_CHAR32)
    return CPP_CHAR32_USERDEF;
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  else if (type == CPP_UTF8CHAR)
    return CPP_UTF8CHAR_USERDEF;
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  else
    return type;
}

/* Return true if the token type is a user-defined string literal.  */
bool
cpp_userdef_string_p (enum cpp_ttype type)
{
  if (type == CPP_STRING_USERDEF
   || type == CPP_WSTRING_USERDEF
   || type == CPP_STRING16_USERDEF
   || type == CPP_STRING32_USERDEF
   || type == CPP_UTF8STRING_USERDEF)
    return true;
  else
    return false;
}

/* Return true if the token type is a user-defined char literal.  */
bool
cpp_userdef_char_p (enum cpp_ttype type)
{
  if (type == CPP_CHAR_USERDEF
   || type == CPP_WCHAR_USERDEF
   || type == CPP_CHAR16_USERDEF
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   || type == CPP_CHAR32_USERDEF
   || type == CPP_UTF8CHAR_USERDEF)
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    return true;
  else
    return false;
}

/* Extract the suffix from a user-defined literal string or char.  */
const char *
cpp_get_userdef_suffix (const cpp_token *tok)
{
  unsigned int len = tok->val.str.len;
  const char *text = (const char *)tok->val.str.text;
  char delim;
  unsigned int i;
  for (i = 0; i < len; ++i)
    if (text[i] == '\'' || text[i] == '"')
      break;
  if (i == len)
    return text + len;
  delim = text[i];
  for (i = len; i > 0; --i)
    if (text[i - 1] == delim)
      break;
  return text + i;
}

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/* Categorize numeric constants according to their field (integer,
   floating point, or invalid), radix (decimal, octal, hexadecimal),
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   and type suffixes.

   TOKEN is the token that represents the numeric constant to
   classify.

   In C++0X if UD_SUFFIX is non null it will be assigned
   any unrecognized suffix for a user-defined literal.

   VIRTUAL_LOCATION is the virtual location for TOKEN.  */
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unsigned int
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cpp_classify_number (cpp_reader *pfile, const cpp_token *token,
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		     const char **ud_suffix, source_location virtual_location)
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{
  const uchar *str = token->val.str.text;
  const uchar *limit;
  unsigned int max_digit, result, radix;
  enum {NOT_FLOAT = 0, AFTER_POINT, AFTER_EXPON} float_flag;
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  bool seen_digit;
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  bool seen_digit_sep;
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  if (ud_suffix)
    *ud_suffix = NULL;

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  /* If the lexer has done its job, length one can only be a single
     digit.  Fast-path this very common case.  */
  if (token->val.str.len == 1)
    return CPP_N_INTEGER | CPP_N_SMALL | CPP_N_DECIMAL;

  limit = str + token->val.str.len;
  float_flag = NOT_FLOAT;
  max_digit = 0;
  radix = 10;
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  seen_digit = false;
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  seen_digit_sep = false;
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  /* First, interpret the radix.  */
  if (*str == '0')
    {
      radix = 8;
      str++;

      /* Require at least one hex digit to classify it as hex.  */
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      if (*str == 'x' || *str == 'X')
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	{
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	  if (str[1] == '.' || ISXDIGIT (str[1]))
	    {
	      radix = 16;
	      str++;
	    }
	  else if (DIGIT_SEP (str[1]))
	    SYNTAX_ERROR_AT (virtual_location,
			     "digit separator after base indicator");
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	}
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      else if (*str == 'b' || *str == 'B')
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	{
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	  if (str[1] == '0' || str[1] == '1')
	    {
	      radix = 2;
	      str++;
	    }
	  else if (DIGIT_SEP (str[1]))
	    SYNTAX_ERROR_AT (virtual_location,
			     "digit separator after base indicator");
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	}
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    }

  /* Now scan for a well-formed integer or float.  */
  for (;;)
    {
      unsigned int c = *str++;

      if (ISDIGIT (c) || (ISXDIGIT (c) && radix == 16))
	{
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	  seen_digit_sep = false;
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	  seen_digit = true;
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	  c = hex_value (c);
	  if (c > max_digit)
	    max_digit = c;
	}
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      else if (DIGIT_SEP (c))
	{
	  if (seen_digit_sep)
	    SYNTAX_ERROR_AT (virtual_location, "adjacent digit separators");
	  seen_digit_sep = true;
	}
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      else if (c == '.')
	{
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	  if (seen_digit_sep || DIGIT_SEP (*str))
	    SYNTAX_ERROR_AT (virtual_location,
			     "digit separator adjacent to decimal point");
	  seen_digit_sep = false;
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	  if (float_flag == NOT_FLOAT)
	    float_flag = AFTER_POINT;
	  else
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	    SYNTAX_ERROR_AT (virtual_location,
			     "too many decimal points in number");
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	}
      else if ((radix <= 10 && (c == 'e' || c == 'E'))
	       || (radix == 16 && (c == 'p' || c == 'P')))
	{
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	  if (seen_digit_sep || DIGIT_SEP (*str))
	    SYNTAX_ERROR_AT (virtual_location,
			     "digit separator adjacent to exponent");
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	  float_flag = AFTER_EXPON;
	  break;
	}
      else
	{
	  /* Start of suffix.  */
	  str--;
	  break;
	}
    }

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  if (seen_digit_sep && float_flag != AFTER_EXPON)
    SYNTAX_ERROR_AT (virtual_location,
		     "digit separator outside digit sequence");

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  /* The suffix may be for decimal fixed-point constants without exponent.  */
  if (radix != 16 && float_flag == NOT_FLOAT)
    {
618
      result = interpret_float_suffix (pfile, str, limit - str);
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      if ((result & CPP_N_FRACT) || (result & CPP_N_ACCUM))
	{
	  result |= CPP_N_FLOATING;
	  /* We need to restore the radix to 10, if the radix is 8.  */
	  if (radix == 8)
	    radix = 10;

	  if (CPP_PEDANTIC (pfile))
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	    cpp_error_with_line (pfile, CPP_DL_PEDWARN, virtual_location, 0,
				 "fixed-point constants are a GCC extension");
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	  goto syntax_ok;
	}
      else
	result = 0;
    }

635 636 637 638
  if (float_flag != NOT_FLOAT && radix == 8)
    radix = 10;

  if (max_digit >= radix)
639 640
    {
      if (radix == 2)
641 642
	SYNTAX_ERROR2_AT (virtual_location,
			  "invalid digit \"%c\" in binary constant", '0' + max_digit);
643
      else
644 645
	SYNTAX_ERROR2_AT (virtual_location,
			  "invalid digit \"%c\" in octal constant", '0' + max_digit);
646
    }
647 648 649

  if (float_flag != NOT_FLOAT)
    {
650 651
      if (radix == 2)
	{
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	  cpp_error_with_line (pfile, CPP_DL_ERROR, virtual_location, 0,
			       "invalid prefix \"0b\" for floating constant");
654 655 656
	  return CPP_N_INVALID;
	}

657
      if (radix == 16 && !seen_digit)
658 659
	SYNTAX_ERROR_AT (virtual_location,
			 "no digits in hexadecimal floating constant");
660

661 662 663 664 665
      if (radix == 16 && CPP_PEDANTIC (pfile)
	  && !CPP_OPTION (pfile, extended_numbers))
	{
	  if (CPP_OPTION (pfile, cplusplus))
	    cpp_error_with_line (pfile, CPP_DL_PEDWARN, virtual_location, 0,
666
				 "use of C++17 hexadecimal floating constant");
667 668 669 670
	  else
	    cpp_error_with_line (pfile, CPP_DL_PEDWARN, virtual_location, 0,
				 "use of C99 hexadecimal floating constant");
	}
671 672 673 674 675 676 677 678

      if (float_flag == AFTER_EXPON)
	{
	  if (*str == '+' || *str == '-')
	    str++;

	  /* Exponent is decimal, even if string is a hex float.  */
	  if (!ISDIGIT (*str))
679 680 681 682 683 684 685
	    {
	      if (DIGIT_SEP (*str))
		SYNTAX_ERROR_AT (virtual_location,
				 "digit separator adjacent to exponent");
	      else
		SYNTAX_ERROR_AT (virtual_location, "exponent has no digits");
	    }
686
	  do
687 688 689 690 691
	    {
	      seen_digit_sep = DIGIT_SEP (*str);
	      str++;
	    }
	  while (ISDIGIT (*str) || DIGIT_SEP (*str));
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	}
      else if (radix == 16)
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	SYNTAX_ERROR_AT (virtual_location,
			 "hexadecimal floating constants require an exponent");
696

697 698 699 700
      if (seen_digit_sep)
	SYNTAX_ERROR_AT (virtual_location,
			 "digit separator outside digit sequence");

701
      result = interpret_float_suffix (pfile, str, limit - str);
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      if (result == 0)
	{
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	  if (CPP_OPTION (pfile, user_literals))
	    {
	      if (ud_suffix)
		*ud_suffix = (const char *) str;
	      result = CPP_N_LARGE | CPP_N_USERDEF;
	    }
	  else
	    {
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	      cpp_error_with_line (pfile, CPP_DL_ERROR, virtual_location, 0,
				   "invalid suffix \"%.*s\" on floating constant",
				   (int) (limit - str), str);
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	      return CPP_N_INVALID;
	    }
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	}

      /* Traditional C didn't accept any floating suffixes.  */
      if (limit != str
	  && CPP_WTRADITIONAL (pfile)
	  && ! cpp_sys_macro_p (pfile))
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	cpp_warning_with_line (pfile, CPP_W_TRADITIONAL, virtual_location, 0,
			       "traditional C rejects the \"%.*s\" suffix",
			       (int) (limit - str), str);
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      /* A suffix for double is a GCC extension via decimal float support.
	 If the suffix also specifies an imaginary value we'll catch that
	 later.  */
      if ((result == CPP_N_MEDIUM) && CPP_PEDANTIC (pfile))
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	cpp_error_with_line (pfile, CPP_DL_PEDWARN, virtual_location, 0,
			     "suffix for double constant is a GCC extension");
733

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      /* Radix must be 10 for decimal floats.  */
      if ((result & CPP_N_DFLOAT) && radix != 10)
        {
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          cpp_error_with_line (pfile, CPP_DL_ERROR, virtual_location, 0,
			       "invalid suffix \"%.*s\" with hexadecimal floating constant",
			       (int) (limit - str), str);
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          return CPP_N_INVALID;
        }

743
      if ((result & (CPP_N_FRACT | CPP_N_ACCUM)) && CPP_PEDANTIC (pfile))
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	cpp_error_with_line (pfile, CPP_DL_PEDWARN, virtual_location, 0,
			     "fixed-point constants are a GCC extension");
746

747
      if ((result & CPP_N_DFLOAT) && CPP_PEDANTIC (pfile))
748 749
	cpp_error_with_line (pfile, CPP_DL_PEDWARN, virtual_location, 0,
			     "decimal float constants are a GCC extension");
750

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      result |= CPP_N_FLOATING;
    }
  else
    {
755
      result = interpret_int_suffix (pfile, str, limit - str);
756 757
      if (result == 0)
	{
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	  if (CPP_OPTION (pfile, user_literals))
	    {
	      if (ud_suffix)
		*ud_suffix = (const char *) str;
	      result = CPP_N_UNSIGNED | CPP_N_LARGE | CPP_N_USERDEF;
	    }
	  else
	    {
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	      cpp_error_with_line (pfile, CPP_DL_ERROR, virtual_location, 0,
				   "invalid suffix \"%.*s\" on integer constant",
				   (int) (limit - str), str);
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	      return CPP_N_INVALID;
	    }
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	}

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      /* Traditional C only accepted the 'L' suffix.
         Suppress warning about 'LL' with -Wno-long-long.  */
      if (CPP_WTRADITIONAL (pfile) && ! cpp_sys_macro_p (pfile))
	{
	  int u_or_i = (result & (CPP_N_UNSIGNED|CPP_N_IMAGINARY));
778
	  int large = (result & CPP_N_WIDTH) == CPP_N_LARGE
779
		       && CPP_OPTION (pfile, cpp_warn_long_long);
780

781
	  if (u_or_i || large)
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	    cpp_warning_with_line (pfile, large ? CPP_W_LONG_LONG : CPP_W_TRADITIONAL,
				   virtual_location, 0,
				   "traditional C rejects the \"%.*s\" suffix",
				   (int) (limit - str), str);
786
	}
787 788

      if ((result & CPP_N_WIDTH) == CPP_N_LARGE
789
	  && CPP_OPTION (pfile, cpp_warn_long_long))
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        {
          const char *message = CPP_OPTION (pfile, cplusplus) 
Jakub Jelinek committed
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				? N_("use of C++11 long long integer constant")
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		                : N_("use of C99 long long integer constant");

	  if (CPP_OPTION (pfile, c99))
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            cpp_warning_with_line (pfile, CPP_W_LONG_LONG, virtual_location,
				   0, message);
798
          else
799 800
            cpp_pedwarning_with_line (pfile, CPP_W_LONG_LONG,
				      virtual_location, 0, message);
801
        }
802 803 804 805

      result |= CPP_N_INTEGER;
    }

806
 syntax_ok:
807
  if ((result & CPP_N_IMAGINARY) && CPP_PEDANTIC (pfile))
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    cpp_error_with_line (pfile, CPP_DL_PEDWARN, virtual_location, 0,
			 "imaginary constants are a GCC extension");
Jakub Jelinek committed
810 811 812
  if (radix == 2
      && !CPP_OPTION (pfile, binary_constants)
      && CPP_PEDANTIC (pfile))
813
    cpp_error_with_line (pfile, CPP_DL_PEDWARN, virtual_location, 0,
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			 CPP_OPTION (pfile, cplusplus)
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			 ? N_("binary constants are a C++14 feature "
			      "or GCC extension")
			 : N_("binary constants are a GCC extension"));
818 819 820 821 822

  if (radix == 10)
    result |= CPP_N_DECIMAL;
  else if (radix == 16)
    result |= CPP_N_HEX;
823 824
  else if (radix == 2)
    result |= CPP_N_BINARY;
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  else
    result |= CPP_N_OCTAL;

  return result;

 syntax_error:
  return CPP_N_INVALID;
}

/* cpp_interpret_integer converts an integer constant into a cpp_num,
   of precision options->precision.

   We do not provide any interface for decimal->float conversion,
838 839
   because the preprocessor doesn't need it and we don't want to
   drag in GCC's floating point emulator.  */
840
cpp_num
841 842
cpp_interpret_integer (cpp_reader *pfile, const cpp_token *token,
		       unsigned int type)
843 844 845 846 847 848
{
  const uchar *p, *end;
  cpp_num result;

  result.low = 0;
  result.high = 0;
849 850
  result.unsignedp = !!(type & CPP_N_UNSIGNED);
  result.overflow = false;
851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874

  p = token->val.str.text;
  end = p + token->val.str.len;

  /* Common case of a single digit.  */
  if (token->val.str.len == 1)
    result.low = p[0] - '0';
  else
    {
      cpp_num_part max;
      size_t precision = CPP_OPTION (pfile, precision);
      unsigned int base = 10, c = 0;
      bool overflow = false;

      if ((type & CPP_N_RADIX) == CPP_N_OCTAL)
	{
	  base = 8;
	  p++;
	}
      else if ((type & CPP_N_RADIX) == CPP_N_HEX)
	{
	  base = 16;
	  p += 2;
	}
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      else if ((type & CPP_N_RADIX) == CPP_N_BINARY)
	{
	  base = 2;
	  p += 2;
	}
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      /* We can add a digit to numbers strictly less than this without
	 needing the precision and slowness of double integers.  */
      max = ~(cpp_num_part) 0;
      if (precision < PART_PRECISION)
	max >>= PART_PRECISION - precision;
      max = (max - base + 1) / base + 1;

      for (; p < end; p++)
	{
	  c = *p;

	  if (ISDIGIT (c) || (base == 16 && ISXDIGIT (c)))
	    c = hex_value (c);
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	  else if (DIGIT_SEP (c))
	    continue;
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	  else
	    break;

	  /* Strict inequality for when max is set to zero.  */
	  if (result.low < max)
	    result.low = result.low * base + c;
	  else
	    {
	      result = append_digit (result, c, base, precision);
	      overflow |= result.overflow;
	      max = 0;
	    }
	}

910
      if (overflow && !(type & CPP_N_USERDEF))
911
	cpp_error (pfile, CPP_DL_PEDWARN,
912
		   "integer constant is too large for its type");
913 914
      /* If too big to be signed, consider it unsigned.  Only warn for
	 decimal numbers.  Traditional numbers were always signed (but
915
	 we still honor an explicit U suffix); but we only have
916
	 traditional semantics in directives.  */
917
      else if (!result.unsignedp
918 919
	       && !(CPP_OPTION (pfile, traditional)
		    && pfile->state.in_directive)
920
	       && !num_positive (result, precision))
921
	{
922
	  /* This is for constants within the range of uintmax_t but
923
	     not that of intmax_t.  For such decimal constants, a
924 925 926 927 928 929 930 931 932 933 934 935 936 937 938
	     diagnostic is required for C99 as the selected type must
	     be signed and not having a type is a constraint violation
	     (DR#298, TC3), so this must be a pedwarn.  For C90,
	     unsigned long is specified to be used for a constant that
	     does not fit in signed long; if uintmax_t has the same
	     range as unsigned long this means only a warning is
	     appropriate here.  C90 permits the preprocessor to use a
	     wider range than unsigned long in the compiler, so if
	     uintmax_t is wider than unsigned long no diagnostic is
	     required for such constants in preprocessor #if
	     expressions and the compiler will pedwarn for such
	     constants outside the range of unsigned long that reach
	     the compiler so a diagnostic is not required there
	     either; thus, pedwarn for C99 but use a plain warning for
	     C90.  */
939
	  if (base == 10)
940 941 942
	    cpp_error (pfile, (CPP_OPTION (pfile, c99)
			       ? CPP_DL_PEDWARN
			       : CPP_DL_WARNING),
943
		       "integer constant is so large that it is unsigned");
944
	  result.unsignedp = true;
945 946 947 948 949
	}
    }

  return result;
}
950

951
/* Append DIGIT to NUM, a number of PRECISION bits being read in base BASE.  */
952
static cpp_num
953
append_digit (cpp_num num, int digit, int base, size_t precision)
954 955
{
  cpp_num result;
956
  unsigned int shift;
957 958 959
  bool overflow;
  cpp_num_part add_high, add_low;

960
  /* Multiply by 2, 8 or 16.  Catching this overflow here means we don't
961
     need to worry about add_high overflowing.  */
962 963 964 965 966 967 968 969 970 971 972 973 974
  switch (base)
    {
    case 2:
      shift = 1;
      break;

    case 16:
      shift = 4;
      break;

    default:
      shift = 3;
    }
975
  overflow = !!(num.high >> (PART_PRECISION - shift));
976 977 978
  result.high = num.high << shift;
  result.low = num.low << shift;
  result.high |= num.low >> (PART_PRECISION - shift);
979
  result.unsignedp = num.unsignedp;
980 981 982 983 984 985 986 987 988 989 990 991

  if (base == 10)
    {
      add_low = num.low << 1;
      add_high = (num.high << 1) + (num.low >> (PART_PRECISION - 1));
    }
  else
    add_high = add_low = 0;

  if (add_low + digit < add_low)
    add_high++;
  add_low += digit;
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993 994 995 996 997 998 999
  if (result.low + add_low < result.low)
    add_high++;
  if (result.high + add_high < result.high)
    overflow = true;

  result.low += add_low;
  result.high += add_high;
1000
  result.overflow = overflow;
1001 1002 1003 1004 1005 1006 1007

  /* The above code catches overflow of a cpp_num type.  This catches
     overflow of the (possibly shorter) target precision.  */
  num.low = result.low;
  num.high = result.high;
  result = num_trim (result, precision);
  if (!num_eq (result, num))
1008
    result.overflow = true;
1009 1010 1011 1012

  return result;
}

1013
/* Handle meeting "defined" in a preprocessor expression.  */
1014
static cpp_num
1015
parse_defined (cpp_reader *pfile)
1016
{
1017
  cpp_num result;
Neil Booth committed
1018 1019
  int paren = 0;
  cpp_hashnode *node = 0;
1020
  const cpp_token *token;
1021
  cpp_context *initial_context = pfile->context;
1022

Neil Booth committed
1023 1024 1025
  /* Don't expand macros.  */
  pfile->state.prevent_expansion++;

1026 1027
  token = cpp_get_token (pfile);
  if (token->type == CPP_OPEN_PAREN)
1028
    {
1029
      paren = 1;
1030
      token = cpp_get_token (pfile);
1031 1032
    }

1033
  if (token->type == CPP_NAME)
Neil Booth committed
1034
    {
1035
      node = token->val.node.node;
1036
      if (paren && cpp_get_token (pfile)->type != CPP_CLOSE_PAREN)
Neil Booth committed
1037
	{
1038
	  cpp_error (pfile, CPP_DL_ERROR, "missing ')' after \"defined\"");
1039
	  node = 0;
Neil Booth committed
1040 1041 1042
	}
    }
  else
1043
    {
1044
      cpp_error (pfile, CPP_DL_ERROR,
1045
		 "operator \"defined\" requires an identifier");
1046
      if (token->flags & NAMED_OP)
1047 1048 1049 1050
	{
	  cpp_token op;

	  op.flags = 0;
1051
	  op.type = token->type;
1052
	  cpp_error (pfile, CPP_DL_ERROR,
1053
		     "(\"%s\" is an alternative token for \"%s\" in C++)",
1054
		     cpp_token_as_text (pfile, token),
1055 1056 1057
		     cpp_token_as_text (pfile, &op));
	}
    }
1058

1059
  if (node)
1060
    {
1061 1062 1063 1064 1065
      if ((pfile->context != initial_context
	   || initial_context != &pfile->base_context)
	  && CPP_OPTION (pfile, warn_expansion_to_defined))
        cpp_pedwarning (pfile, CPP_W_EXPANSION_TO_DEFINED,
		        "this use of \"defined\" may not be portable");
1066

1067
      _cpp_mark_macro_used (node);
1068 1069 1070 1071 1072
      if (!(node->flags & NODE_USED))
	{
	  node->flags |= NODE_USED;
	  if (node->type == NT_MACRO)
	    {
1073 1074 1075
	      if ((node->flags & NODE_BUILTIN)
		  && pfile->cb.user_builtin_macro)
		pfile->cb.user_builtin_macro (pfile, node);
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	      if (pfile->cb.used_define)
		pfile->cb.used_define (pfile, pfile->directive_line, node);
	    }
	  else
	    {
	      if (pfile->cb.used_undef)
		pfile->cb.used_undef (pfile, pfile->directive_line, node);
	    }
	}
1085

1086 1087 1088
      /* A possible controlling macro of the form #if !defined ().
	 _cpp_parse_expr checks there was no other junk on the line.  */
      pfile->mi_ind_cmacro = node;
1089
    }
Neil Booth committed
1090 1091

  pfile->state.prevent_expansion--;
1092

1093 1094 1095 1096
  /* Do not treat conditional macros as being defined.  This is due to the
     powerpc and spu ports using conditional macros for 'vector', 'bool', and
     'pixel' to act as conditional keywords.  This messes up tests like #ifndef
     bool.  */
1097
  result.unsignedp = false;
1098
  result.high = 0;
1099
  result.overflow = false;
1100 1101
  result.low = (node && node->type == NT_MACRO
		&& (node->flags & NODE_CONDITIONAL) == 0);
1102
  return result;
1103 1104
}

1105 1106
/* Convert a token into a CPP_NUMBER (an interpreted preprocessing
   number or character constant, or the result of the "defined" or "#"
1107
   operators).  */
1108
static cpp_num
1109 1110
eval_token (cpp_reader *pfile, const cpp_token *token,
	    source_location virtual_location)
Per Bothner committed
1111
{
1112
  cpp_num result;
1113
  unsigned int temp;
1114
  int unsignedp = 0;
Zack Weinberg committed
1115

1116 1117 1118
  result.unsignedp = false;
  result.overflow = false;

Neil Booth committed
1119
  switch (token->type)
1120
    {
Per Bothner committed
1121
    case CPP_NUMBER:
1122
      temp = cpp_classify_number (pfile, token, NULL, virtual_location);
1123 1124 1125
      if (temp & CPP_N_USERDEF)
	cpp_error (pfile, CPP_DL_ERROR,
		   "user-defined literal in preprocessor expression");
1126 1127 1128
      switch (temp & CPP_N_CATEGORY)
	{
	case CPP_N_FLOATING:
1129 1130
	  cpp_error_with_line (pfile, CPP_DL_ERROR, virtual_location, 0,
			       "floating constant in preprocessor expression");
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	  break;
	case CPP_N_INTEGER:
	  if (!(temp & CPP_N_IMAGINARY))
	    return cpp_interpret_integer (pfile, token, temp);
1135 1136
	  cpp_error_with_line (pfile, CPP_DL_ERROR, virtual_location, 0,
			       "imaginary number in preprocessor expression");
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	  break;

	case CPP_N_INVALID:
	  /* Error already issued.  */
	  break;
	}
      result.high = result.low = 0;
      break;
1145

1146
    case CPP_WCHAR:
1147
    case CPP_CHAR:
1148 1149
    case CPP_CHAR16:
    case CPP_CHAR32:
1150
    case CPP_UTF8CHAR:
1151
      {
1152 1153 1154 1155 1156
	cppchar_t cc = cpp_interpret_charconst (pfile, token,
						&temp, &unsignedp);

	result.high = 0;
	result.low = cc;
1157
	/* Sign-extend the result if necessary.  */
1158 1159 1160 1161 1162 1163 1164 1165
	if (!unsignedp && (cppchar_signed_t) cc < 0)
	  {
	    if (PART_PRECISION > BITS_PER_CPPCHAR_T)
	      result.low |= ~(~(cpp_num_part) 0
			      >> (PART_PRECISION - BITS_PER_CPPCHAR_T));
	    result.high = ~(cpp_num_part) 0;
	    result = num_trim (result, CPP_OPTION (pfile, precision));
	  }
1166
      }
1167
      break;
1168

1169
    case CPP_NAME:
1170
      if (token->val.node.node == pfile->spec_nodes.n_defined)
1171
	return parse_defined (pfile);
1172 1173 1174 1175
      else if (token->val.node.node == pfile->spec_nodes.n__has_include__)
	return parse_has_include (pfile, IT_INCLUDE);
      else if (token->val.node.node == pfile->spec_nodes.n__has_include_next__)
	return parse_has_include (pfile, IT_INCLUDE_NEXT);
1176
      else if (CPP_OPTION (pfile, cplusplus)
1177 1178
	       && (token->val.node.node == pfile->spec_nodes.n_true
		   || token->val.node.node == pfile->spec_nodes.n_false))
1179
	{
1180
	  result.high = 0;
1181
	  result.low = (token->val.node.node == pfile->spec_nodes.n_true);
1182 1183 1184
	}
      else
	{
1185 1186
	  result.high = 0;
	  result.low = 0;
1187
	  if (CPP_OPTION (pfile, warn_undef) && !pfile->state.skip_eval)
1188
	    cpp_warning_with_line (pfile, CPP_W_UNDEF, virtual_location, 0,
1189
				   "\"%s\" is not defined, evaluates to 0",
1190
				   NODE_NAME (token->val.node.node));
Per Bothner committed
1191
	}
1192
      break;
Per Bothner committed
1193

1194 1195 1196 1197 1198 1199
    case CPP_HASH:
      if (!pfile->state.skipping)
	{
	  /* A pedantic warning takes precedence over a deprecated
	     warning here.  */
	  if (CPP_PEDANTIC (pfile))
1200 1201 1202
	    cpp_error_with_line (pfile, CPP_DL_PEDWARN,
				 virtual_location, 0,
				 "assertions are a GCC extension");
1203
	  else if (CPP_OPTION (pfile, cpp_warn_deprecated))
1204 1205
	    cpp_warning_with_line (pfile, CPP_W_DEPRECATED, virtual_location, 0,
				   "assertions are a deprecated extension");
1206
	}
1207 1208 1209
      _cpp_test_assertion (pfile, &temp);
      result.high = 0;
      result.low = temp;
1210 1211 1212 1213
      break;

    default:
      abort ();
Neil Booth committed
1214
    }
Neil Booth committed
1215

1216
  result.unsignedp = !!unsignedp;
1217
  return result;
Per Bothner committed
1218 1219
}

1220
/* Operator precedence and flags table.
1221 1222

After an operator is returned from the lexer, if it has priority less
1223 1224 1225 1226 1227 1228 1229
than the operator on the top of the stack, we reduce the stack by one
operator and repeat the test.  Since equal priorities do not reduce,
this is naturally right-associative.

We handle left-associative operators by decrementing the priority of
just-lexed operators by one, but retaining the priority of operators
already on the stack.
1230 1231 1232 1233

The remaining cases are '(' and ')'.  We handle '(' by skipping the
reduction phase completely.  ')' is given lower priority than
everything else, including '(', effectively forcing a reduction of the
1234
parenthesized expression.  If there is a matching '(', the routine
1235 1236
reduce() exits immediately.  If the normal exit route sees a ')', then
there cannot have been a matching '(' and an error message is output.
1237

1238 1239 1240
The parser assumes all shifted operators require a left operand unless
the flag NO_L_OPERAND is set.  These semantics are automatic; any
extra semantics need to be handled with operator-specific code.  */
1241

1242 1243
/* Flags.  If CHECK_PROMOTION, we warn if the effective sign of an
   operand changes because of integer promotions.  */
1244 1245
#define NO_L_OPERAND	(1 << 0)
#define LEFT_ASSOC	(1 << 1)
1246
#define CHECK_PROMOTION	(1 << 2)
1247

1248 1249
/* Operator to priority map.  Must be in the same order as the first
   N entries of enum cpp_ttype.  */
1250
static const struct cpp_operator
1251
{
1252
  uchar prio;
1253 1254
  uchar flags;
} optab[] =
1255
{
1256 1257
  /* EQ */		{0, 0},	/* Shouldn't happen.  */
  /* NOT */		{16, NO_L_OPERAND},
1258 1259 1260 1261 1262 1263 1264 1265 1266 1267
  /* GREATER */		{12, LEFT_ASSOC | CHECK_PROMOTION},
  /* LESS */		{12, LEFT_ASSOC | CHECK_PROMOTION},
  /* PLUS */		{14, LEFT_ASSOC | CHECK_PROMOTION},
  /* MINUS */		{14, LEFT_ASSOC | CHECK_PROMOTION},
  /* MULT */		{15, LEFT_ASSOC | CHECK_PROMOTION},
  /* DIV */		{15, LEFT_ASSOC | CHECK_PROMOTION},
  /* MOD */		{15, LEFT_ASSOC | CHECK_PROMOTION},
  /* AND */		{9, LEFT_ASSOC | CHECK_PROMOTION},
  /* OR */		{7, LEFT_ASSOC | CHECK_PROMOTION},
  /* XOR */		{8, LEFT_ASSOC | CHECK_PROMOTION},
1268 1269 1270 1271
  /* RSHIFT */		{13, LEFT_ASSOC},
  /* LSHIFT */		{13, LEFT_ASSOC},

  /* COMPL */		{16, NO_L_OPERAND},
1272 1273
  /* AND_AND */		{6, LEFT_ASSOC},
  /* OR_OR */		{5, LEFT_ASSOC},
1274 1275 1276
  /* Note that QUERY, COLON, and COMMA must have the same precedence.
     However, there are some special cases for these in reduce().  */
  /* QUERY */		{4, 0},
1277
  /* COLON */		{4, LEFT_ASSOC | CHECK_PROMOTION},
1278
  /* COMMA */		{4, LEFT_ASSOC},
1279
  /* OPEN_PAREN */	{1, NO_L_OPERAND},
1280 1281 1282 1283
  /* CLOSE_PAREN */	{0, 0},
  /* EOF */		{0, 0},
  /* EQ_EQ */		{11, LEFT_ASSOC},
  /* NOT_EQ */		{11, LEFT_ASSOC},
1284 1285
  /* GREATER_EQ */	{12, LEFT_ASSOC | CHECK_PROMOTION},
  /* LESS_EQ */		{12, LEFT_ASSOC | CHECK_PROMOTION},
1286 1287
  /* UPLUS */		{16, NO_L_OPERAND},
  /* UMINUS */		{16, NO_L_OPERAND}
1288 1289
};

Per Bothner committed
1290
/* Parse and evaluate a C expression, reading from PFILE.
1291
   Returns the truth value of the expression.
1292 1293 1294 1295 1296 1297 1298 1299 1300 1301

   The implementation is an operator precedence parser, i.e. a
   bottom-up parser, using a stack for not-yet-reduced tokens.

   The stack base is op_stack, and the current stack pointer is 'top'.
   There is a stack element for each operator (only), and the most
   recently pushed operator is 'top->op'.  An operand (value) is
   stored in the 'value' field of the stack element of the operator
   that precedes it.  */
bool
1302
_cpp_parse_expr (cpp_reader *pfile, bool is_if)
Per Bothner committed
1303
{
1304 1305 1306
  struct op *top = pfile->op_stack;
  unsigned int lex_count;
  bool saw_leading_not, want_value = true;
1307
  source_location virtual_location = 0;
1308 1309

  pfile->state.skip_eval = 0;
Per Bothner committed
1310

Neil Booth committed
1311
  /* Set up detection of #if ! defined().  */
1312
  pfile->mi_ind_cmacro = 0;
1313
  saw_leading_not = false;
1314
  lex_count = 0;
Neil Booth committed
1315

1316
  /* Lowest priority operator prevents further reductions.  */
1317
  top->op = CPP_EOF;
1318

Per Bothner committed
1319 1320
  for (;;)
    {
1321
      struct op op;
Per Bothner committed
1322

1323
      lex_count++;
1324
      op.token = cpp_get_token_with_location (pfile, &virtual_location);
1325
      op.op = op.token->type;
1326
      op.loc = virtual_location;
Per Bothner committed
1327 1328 1329

      switch (op.op)
	{
1330
	  /* These tokens convert into values.  */
1331
	case CPP_NUMBER:
1332 1333
	case CPP_CHAR:
	case CPP_WCHAR:
1334 1335
	case CPP_CHAR16:
	case CPP_CHAR32:
1336
	case CPP_UTF8CHAR:
1337 1338
	case CPP_NAME:
	case CPP_HASH:
1339
	  if (!want_value)
1340 1341 1342
	    SYNTAX_ERROR2_AT (op.loc,
			      "missing binary operator before token \"%s\"",
			      cpp_token_as_text (pfile, op.token));
1343
	  want_value = false;
1344
	  top->value = eval_token (pfile, op.token, op.loc);
1345 1346
	  continue;

1347 1348 1349
	case CPP_NOT:
	  saw_leading_not = lex_count == 1;
	  break;
1350
	case CPP_PLUS:
1351 1352 1353 1354 1355 1356 1357
	  if (want_value)
	    op.op = CPP_UPLUS;
	  break;
	case CPP_MINUS:
	  if (want_value)
	    op.op = CPP_UMINUS;
	  break;
1358

1359
	default:
1360
	  if ((int) op.op <= (int) CPP_EQ || (int) op.op >= (int) CPP_PLUS_EQ)
1361 1362 1363
	    SYNTAX_ERROR2_AT (op.loc,
			      "token \"%s\" is not valid in preprocessor expressions",
			      cpp_token_as_text (pfile, op.token));
1364
	  break;
Per Bothner committed
1365 1366
	}

1367 1368
      /* Check we have a value or operator as appropriate.  */
      if (optab[op.op].flags & NO_L_OPERAND)
Per Bothner committed
1369
	{
1370
	  if (!want_value)
1371 1372 1373
	    SYNTAX_ERROR2_AT (op.loc,
			      "missing binary operator before token \"%s\"",
			      cpp_token_as_text (pfile, op.token));
1374 1375 1376
	}
      else if (want_value)
	{
1377 1378 1379
	  /* We want a number (or expression) and haven't got one.
	     Try to emit a specific diagnostic.  */
	  if (op.op == CPP_CLOSE_PAREN && top->op == CPP_OPEN_PAREN)
1380 1381
	    SYNTAX_ERROR_AT (op.loc,
			     "missing expression between '(' and ')'");
1382 1383

	  if (op.op == CPP_EOF && top->op == CPP_EOF)
1384 1385
 	    SYNTAX_ERROR2_AT (op.loc,
			      "%s with no expression", is_if ? "#if" : "#elif");
1386 1387

 	  if (top->op != CPP_EOF && top->op != CPP_OPEN_PAREN)
1388 1389 1390
 	    SYNTAX_ERROR2_AT (op.loc,
			      "operator '%s' has no right operand",
			      cpp_token_as_text (pfile, top->token));
1391 1392 1393
	  else if (op.op == CPP_CLOSE_PAREN || op.op == CPP_EOF)
	    /* Complain about missing paren during reduction.  */;
	  else
1394 1395 1396
	    SYNTAX_ERROR2_AT (op.loc,
			      "operator '%s' has no left operand",
			      cpp_token_as_text (pfile, op.token));
Per Bothner committed
1397
	}
1398

1399 1400 1401
      top = reduce (pfile, top, op.op);
      if (!top)
	goto syntax_error;
1402

1403 1404 1405
      if (op.op == CPP_EOF)
	break;

1406
      switch (op.op)
Neil Booth committed
1407
	{
1408 1409 1410
	case CPP_CLOSE_PAREN:
	  continue;
	case CPP_OR_OR:
1411
	  if (!num_zerop (top->value))
1412 1413 1414 1415
	    pfile->state.skip_eval++;
	  break;
	case CPP_AND_AND:
	case CPP_QUERY:
1416
	  if (num_zerop (top->value))
1417 1418 1419
	    pfile->state.skip_eval++;
	  break;
	case CPP_COLON:
1420
	  if (top->op != CPP_QUERY)
1421 1422
	    SYNTAX_ERROR_AT (op.loc,
			     " ':' without preceding '?'");
1423
	  if (!num_zerop (top[-1].value)) /* Was '?' condition true?  */
1424 1425 1426 1427 1428
	    pfile->state.skip_eval++;
	  else
	    pfile->state.skip_eval--;
	default:
	  break;
1429
	}
1430

1431
      want_value = true;
1432

Mike Stump committed
1433
      /* Check for and handle stack overflow.  */
1434 1435
      if (++top == pfile->op_limit)
	top = _cpp_expand_op_stack (pfile);
1436

Per Bothner committed
1437
      top->op = op.op;
1438
      top->token = op.token;
1439
      top->loc = op.loc;
Per Bothner committed
1440
    }
1441

1442 1443 1444 1445 1446 1447
  /* The controlling macro expression is only valid if we called lex 3
     times: <!> <defined expression> and <EOF>.  push_conditional ()
     checks that we are at top-of-file.  */
  if (pfile->mi_ind_cmacro && !(saw_leading_not && lex_count == 3))
    pfile->mi_ind_cmacro = 0;

1448
  if (top != pfile->op_stack)
1449
    {
1450 1451 1452
      cpp_error_with_line (pfile, CPP_DL_ICE, top->loc, 0,
			   "unbalanced stack in %s",
			   is_if ? "#if" : "#elif");
1453
    syntax_error:
1454
      return false;  /* Return false on syntax error.  */
1455
    }
1456

1457
  return !num_zerop (top->value);
1458 1459 1460 1461 1462 1463
}

/* Reduce the operator / value stack if possible, in preparation for
   pushing operator OP.  Returns NULL on error, otherwise the top of
   the stack.  */
static struct op *
1464
reduce (cpp_reader *pfile, struct op *top, enum cpp_ttype op)
1465 1466 1467
{
  unsigned int prio;

1468 1469 1470
  if (top->op <= CPP_EQ || top->op > CPP_LAST_CPP_OP + 2)
    {
    bad_op:
1471
      cpp_error (pfile, CPP_DL_ICE, "impossible operator '%u'", top->op);
1472 1473 1474
      return 0;
    }

1475 1476 1477 1478 1479 1480 1481 1482
  if (op == CPP_OPEN_PAREN)
    return top;

  /* Decrement the priority of left-associative operators to force a
     reduction with operators of otherwise equal priority.  */
  prio = optab[op].prio - ((optab[op].flags & LEFT_ASSOC) != 0);
  while (prio < optab[top->op].prio)
    {
1483 1484 1485 1486
      if (CPP_OPTION (pfile, warn_num_sign_change)
	  && optab[top->op].flags & CHECK_PROMOTION)
	check_promotion (pfile, top);

1487 1488 1489 1490 1491 1492 1493
      switch (top->op)
	{
	case CPP_UPLUS:
	case CPP_UMINUS:
	case CPP_NOT:
	case CPP_COMPL:
	  top[-1].value = num_unary_op (pfile, top->value, top->op);
1494
	  top[-1].loc = top->loc;
1495
	  break;
1496

1497 1498 1499 1500 1501 1502 1503
	case CPP_PLUS:
	case CPP_MINUS:
	case CPP_RSHIFT:
	case CPP_LSHIFT:
	case CPP_COMMA:
	  top[-1].value = num_binary_op (pfile, top[-1].value,
					 top->value, top->op);
1504
	  top[-1].loc = top->loc;
1505
	  break;
1506

1507 1508 1509 1510 1511 1512
	case CPP_GREATER:
	case CPP_LESS:
	case CPP_GREATER_EQ:
	case CPP_LESS_EQ:
	  top[-1].value
	    = num_inequality_op (pfile, top[-1].value, top->value, top->op);
1513
	  top[-1].loc = top->loc;
1514
	  break;
1515

1516 1517 1518 1519
	case CPP_EQ_EQ:
	case CPP_NOT_EQ:
	  top[-1].value
	    = num_equality_op (pfile, top[-1].value, top->value, top->op);
1520
	  top[-1].loc = top->loc;
1521
	  break;
1522

1523 1524 1525 1526 1527
	case CPP_AND:
	case CPP_OR:
	case CPP_XOR:
	  top[-1].value
	    = num_bitwise_op (pfile, top[-1].value, top->value, top->op);
1528
	  top[-1].loc = top->loc;
1529
	  break;
1530

1531 1532
	case CPP_MULT:
	  top[-1].value = num_mul (pfile, top[-1].value, top->value);
1533
	  top[-1].loc = top->loc;
1534
	  break;
1535

1536 1537 1538
	case CPP_DIV:
	case CPP_MOD:
	  top[-1].value = num_div_op (pfile, top[-1].value,
1539
				      top->value, top->op, top->loc);
1540
	  top[-1].loc = top->loc;
1541
	  break;
1542

1543 1544 1545 1546 1547 1548 1549 1550 1551
	case CPP_OR_OR:
	  top--;
	  if (!num_zerop (top->value))
	    pfile->state.skip_eval--;
	  top->value.low = (!num_zerop (top->value)
			    || !num_zerop (top[1].value));
	  top->value.high = 0;
	  top->value.unsignedp = false;
	  top->value.overflow = false;
1552
	  top->loc = top[1].loc;
1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563
	  continue;

	case CPP_AND_AND:
	  top--;
	  if (num_zerop (top->value))
	    pfile->state.skip_eval--;
	  top->value.low = (!num_zerop (top->value)
			    && !num_zerop (top[1].value));
	  top->value.high = 0;
	  top->value.unsignedp = false;
	  top->value.overflow = false;
1564
	  top->loc = top[1].loc;
1565 1566 1567 1568 1569
	  continue;

	case CPP_OPEN_PAREN:
	  if (op != CPP_CLOSE_PAREN)
	    {
1570 1571 1572
	      cpp_error_with_line (pfile, CPP_DL_ERROR, 
				   top->token->src_loc,
				   0, "missing ')' in expression");
1573 1574 1575 1576
	      return 0;
	    }
	  top--;
	  top->value = top[1].value;
1577
	  top->loc = top[1].loc;
1578 1579 1580 1581 1582 1583
	  return top;

	case CPP_COLON:
	  top -= 2;
	  if (!num_zerop (top->value))
	    {
1584
	      pfile->state.skip_eval--;
1585
	      top->value = top[1].value;
1586
	      top->loc = top[1].loc;
1587 1588
	    }
	  else
1589 1590 1591 1592
	    {
	      top->value = top[2].value;
	      top->loc = top[2].loc;
	    }
1593 1594 1595 1596 1597
	  top->value.unsignedp = (top[1].value.unsignedp
				  || top[2].value.unsignedp);
	  continue;

	case CPP_QUERY:
1598 1599 1600
	  /* COMMA and COLON should not reduce a QUERY operator.  */
	  if (op == CPP_COMMA || op == CPP_COLON)
	    return top;
1601
	  cpp_error (pfile, CPP_DL_ERROR, "'?' without following ':'");
1602 1603 1604 1605 1606
	  return 0;

	default:
	  goto bad_op;
	}
1607

1608
      top--;
1609
      if (top->value.overflow && !pfile->state.skip_eval)
1610
	cpp_error (pfile, CPP_DL_PEDWARN,
1611
		   "integer overflow in preprocessor expression");
1612 1613 1614 1615
    }

  if (op == CPP_CLOSE_PAREN)
    {
1616
      cpp_error (pfile, CPP_DL_ERROR, "missing '(' in expression");
1617 1618 1619 1620 1621 1622 1623 1624
      return 0;
    }

  return top;
}

/* Returns the position of the old top of stack after expansion.  */
struct op *
1625
_cpp_expand_op_stack (cpp_reader *pfile)
1626
{
1627 1628
  size_t old_size = (size_t) (pfile->op_limit - pfile->op_stack);
  size_t new_size = old_size * 2 + 20;
1629

1630
  pfile->op_stack = XRESIZEVEC (struct op, pfile->op_stack, new_size);
1631
  pfile->op_limit = pfile->op_stack + new_size;
1632

1633
  return pfile->op_stack + old_size;
Per Bothner committed
1634
}
1635

1636 1637 1638
/* Emits a warning if the effective sign of either operand of OP
   changes because of integer promotions.  */
static void
1639
check_promotion (cpp_reader *pfile, const struct op *op)
1640 1641 1642 1643 1644 1645 1646
{
  if (op->value.unsignedp == op[-1].value.unsignedp)
    return;

  if (op->value.unsignedp)
    {
      if (!num_positive (op[-1].value, CPP_OPTION (pfile, precision)))
1647 1648 1649
	cpp_error_with_line (pfile, CPP_DL_WARNING, op[-1].loc, 0,
			     "the left operand of \"%s\" changes sign when promoted",
			     cpp_token_as_text (pfile, op->token));
1650 1651
    }
  else if (!num_positive (op->value, CPP_OPTION (pfile, precision)))
1652
    cpp_error_with_line (pfile, CPP_DL_WARNING, op->loc, 0,
1653 1654 1655 1656
	       "the right operand of \"%s\" changes sign when promoted",
	       cpp_token_as_text (pfile, op->token));
}

1657 1658
/* Clears the unused high order bits of the number pointed to by PNUM.  */
static cpp_num
1659
num_trim (cpp_num num, size_t precision)
1660 1661 1662 1663 1664
{
  if (precision > PART_PRECISION)
    {
      precision -= PART_PRECISION;
      if (precision < PART_PRECISION)
1665
	num.high &= ((cpp_num_part) 1 << precision) - 1;
1666 1667 1668 1669
    }
  else
    {
      if (precision < PART_PRECISION)
1670
	num.low &= ((cpp_num_part) 1 << precision) - 1;
1671 1672 1673 1674 1675 1676 1677 1678
      num.high = 0;
    }

  return num;
}

/* True iff A (presumed signed) >= 0.  */
static bool
1679
num_positive (cpp_num num, size_t precision)
1680 1681 1682 1683
{
  if (precision > PART_PRECISION)
    {
      precision -= PART_PRECISION;
1684
      return (num.high & (cpp_num_part) 1 << (precision - 1)) == 0;
1685 1686
    }

1687
  return (num.low & (cpp_num_part) 1 << (precision - 1)) == 0;
1688 1689
}

1690 1691 1692
/* Sign extend a number, with PRECISION significant bits and all
   others assumed clear, to fill out a cpp_num structure.  */
cpp_num
1693
cpp_num_sign_extend (cpp_num num, size_t precision)
1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714
{
  if (!num.unsignedp)
    {
      if (precision > PART_PRECISION)
	{
	  precision -= PART_PRECISION;
	  if (precision < PART_PRECISION
	      && (num.high & (cpp_num_part) 1 << (precision - 1)))
	    num.high |= ~(~(cpp_num_part) 0 >> (PART_PRECISION - precision));
	}
      else if (num.low & (cpp_num_part) 1 << (precision - 1))
	{
	  if (precision < PART_PRECISION)
	    num.low |= ~(~(cpp_num_part) 0 >> (PART_PRECISION - precision));
	  num.high = ~(cpp_num_part) 0;
	}
    }

  return num;
}

1715 1716
/* Returns the negative of NUM.  */
static cpp_num
1717
num_negate (cpp_num num, size_t precision)
1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733
{
  cpp_num copy;

  copy = num;
  num.high = ~num.high;
  num.low = ~num.low;
  if (++num.low == 0)
    num.high++;
  num = num_trim (num, precision);
  num.overflow = (!num.unsignedp && num_eq (num, copy) && !num_zerop (num));

  return num;
}

/* Returns true if A >= B.  */
static bool
1734
num_greater_eq (cpp_num pa, cpp_num pb, size_t precision)
1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756
{
  bool unsignedp;

  unsignedp = pa.unsignedp || pb.unsignedp;

  if (!unsignedp)
    {
      /* Both numbers have signed type.  If they are of different
       sign, the answer is the sign of A.  */
      unsignedp = num_positive (pa, precision);

      if (unsignedp != num_positive (pb, precision))
	return unsignedp;

      /* Otherwise we can do an unsigned comparison.  */
    }

  return (pa.high > pb.high) || (pa.high == pb.high && pa.low >= pb.low);
}

/* Returns LHS OP RHS, where OP is a bit-wise operation.  */
static cpp_num
1757 1758
num_bitwise_op (cpp_reader *pfile ATTRIBUTE_UNUSED,
		cpp_num lhs, cpp_num rhs, enum cpp_ttype op)
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{
  lhs.overflow = false;
  lhs.unsignedp = lhs.unsignedp || rhs.unsignedp;

  /* As excess precision is zeroed, there is no need to num_trim () as
     these operations cannot introduce a set bit there.  */
  if (op == CPP_AND)
    {
      lhs.low &= rhs.low;
      lhs.high &= rhs.high;
    }
  else if (op == CPP_OR)
    {
      lhs.low |= rhs.low;
      lhs.high |= rhs.high;
    }
  else
    {
      lhs.low ^= rhs.low;
      lhs.high ^= rhs.high;
    }

  return lhs;
}

/* Returns LHS OP RHS, where OP is an inequality.  */
static cpp_num
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num_inequality_op (cpp_reader *pfile, cpp_num lhs, cpp_num rhs,
		   enum cpp_ttype op)
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{
  bool gte = num_greater_eq (lhs, rhs, CPP_OPTION (pfile, precision));

  if (op == CPP_GREATER_EQ)
    lhs.low = gte;
  else if (op == CPP_LESS)
    lhs.low = !gte;
  else if (op == CPP_GREATER)
    lhs.low = gte && !num_eq (lhs, rhs);
  else /* CPP_LESS_EQ.  */
    lhs.low = !gte || num_eq (lhs, rhs);

  lhs.high = 0;
  lhs.overflow = false;
  lhs.unsignedp = false;
  return lhs;
}

/* Returns LHS OP RHS, where OP is == or !=.  */
static cpp_num
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num_equality_op (cpp_reader *pfile ATTRIBUTE_UNUSED,
		 cpp_num lhs, cpp_num rhs, enum cpp_ttype op)
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{
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  /* Work around a 3.0.4 bug; see PR 6950.  */
  bool eq = num_eq (lhs, rhs);
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  if (op == CPP_NOT_EQ)
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    eq = !eq;
  lhs.low = eq;
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  lhs.high = 0;
  lhs.overflow = false;
  lhs.unsignedp = false;
  return lhs;
}

/* Shift NUM, of width PRECISION, right by N bits.  */
static cpp_num
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num_rshift (cpp_num num, size_t precision, size_t n)
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{
  cpp_num_part sign_mask;
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  bool x = num_positive (num, precision);
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  if (num.unsignedp || x)
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    sign_mask = 0;
  else
    sign_mask = ~(cpp_num_part) 0;

  if (n >= precision)
    num.high = num.low = sign_mask;
  else
    {
      /* Sign-extend.  */
      if (precision < PART_PRECISION)
	num.high = sign_mask, num.low |= sign_mask << precision;
      else if (precision < 2 * PART_PRECISION)
	num.high |= sign_mask << (precision - PART_PRECISION);

      if (n >= PART_PRECISION)
	{
	  n -= PART_PRECISION;
	  num.low = num.high;
	  num.high = sign_mask;
	}

      if (n)
	{
	  num.low = (num.low >> n) | (num.high << (PART_PRECISION - n));
	  num.high = (num.high >> n) | (sign_mask << (PART_PRECISION - n));
	}
    }

  num = num_trim (num, precision);
  num.overflow = false;
  return num;
}

/* Shift NUM, of width PRECISION, left by N bits.  */
static cpp_num
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num_lshift (cpp_num num, size_t precision, size_t n)
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{
  if (n >= precision)
    {
      num.overflow = !num.unsignedp && !num_zerop (num);
      num.high = num.low = 0;
    }
  else
    {
      cpp_num orig, maybe_orig;
      size_t m = n;

      orig = num;
      if (m >= PART_PRECISION)
	{
	  m -= PART_PRECISION;
	  num.high = num.low;
	  num.low = 0;
	}
      if (m)
	{
	  num.high = (num.high << m) | (num.low >> (PART_PRECISION - m));
	  num.low <<= m;
	}
      num = num_trim (num, precision);

      if (num.unsignedp)
	num.overflow = false;
      else
	{
	  maybe_orig = num_rshift (num, precision, n);
	  num.overflow = !num_eq (orig, maybe_orig);
	}
    }

  return num;
}

/* The four unary operators: +, -, ! and ~.  */
static cpp_num
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num_unary_op (cpp_reader *pfile, cpp_num num, enum cpp_ttype op)
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{
  switch (op)
    {
    case CPP_UPLUS:
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      if (CPP_WTRADITIONAL (pfile) && !pfile->state.skip_eval)
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	cpp_warning (pfile, CPP_W_TRADITIONAL,
		     "traditional C rejects the unary plus operator");
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      num.overflow = false;
      break;

    case CPP_UMINUS:
      num = num_negate (num, CPP_OPTION (pfile, precision));
      break;

    case CPP_COMPL:
      num.high = ~num.high;
      num.low = ~num.low;
      num = num_trim (num, CPP_OPTION (pfile, precision));
      num.overflow = false;
      break;

    default: /* case CPP_NOT: */
      num.low = num_zerop (num);
      num.high = 0;
      num.overflow = false;
      num.unsignedp = false;
      break;
    }

  return num;
}

/* The various binary operators.  */
static cpp_num
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num_binary_op (cpp_reader *pfile, cpp_num lhs, cpp_num rhs, enum cpp_ttype op)
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{
  cpp_num result;
  size_t precision = CPP_OPTION (pfile, precision);
  size_t n;

  switch (op)
    {
      /* Shifts.  */
    case CPP_LSHIFT:
    case CPP_RSHIFT:
      if (!rhs.unsignedp && !num_positive (rhs, precision))
	{
	  /* A negative shift is a positive shift the other way.  */
	  if (op == CPP_LSHIFT)
	    op = CPP_RSHIFT;
	  else
	    op = CPP_LSHIFT;
	  rhs = num_negate (rhs, precision);
	}
      if (rhs.high)
	n = ~0;			/* Maximal.  */
      else
	n = rhs.low;
      if (op == CPP_LSHIFT)
	lhs = num_lshift (lhs, precision, n);
      else
	lhs = num_rshift (lhs, precision, n);
      break;

      /* Arithmetic.  */
    case CPP_MINUS:
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      result.low = lhs.low - rhs.low;
      result.high = lhs.high - rhs.high;
      if (result.low > lhs.low)
	result.high--;
      result.unsignedp = lhs.unsignedp || rhs.unsignedp;
      result.overflow = false;

      result = num_trim (result, precision);
      if (!result.unsignedp)
	{
	  bool lhsp = num_positive (lhs, precision);
	  result.overflow = (lhsp != num_positive (rhs, precision)
			     && lhsp != num_positive (result, precision));
	}
      return result;

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    case CPP_PLUS:
      result.low = lhs.low + rhs.low;
      result.high = lhs.high + rhs.high;
      if (result.low < lhs.low)
	result.high++;
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      result.unsignedp = lhs.unsignedp || rhs.unsignedp;
      result.overflow = false;
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      result = num_trim (result, precision);
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      if (!result.unsignedp)
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	{
	  bool lhsp = num_positive (lhs, precision);
	  result.overflow = (lhsp == num_positive (rhs, precision)
			     && lhsp != num_positive (result, precision));
	}
      return result;

      /* Comma.  */
    default: /* case CPP_COMMA: */
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      if (CPP_PEDANTIC (pfile) && (!CPP_OPTION (pfile, c99)
				   || !pfile->state.skip_eval))
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	cpp_pedwarning (pfile, CPP_W_PEDANTIC,
			"comma operator in operand of #if");
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      lhs = rhs;
      break;
    }

  return lhs;
}

/* Multiplies two unsigned cpp_num_parts to give a cpp_num.  This
   cannot overflow.  */
static cpp_num
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num_part_mul (cpp_num_part lhs, cpp_num_part rhs)
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{
  cpp_num result;
  cpp_num_part middle[2], temp;

  result.low = LOW_PART (lhs) * LOW_PART (rhs);
  result.high = HIGH_PART (lhs) * HIGH_PART (rhs);

  middle[0] = LOW_PART (lhs) * HIGH_PART (rhs);
  middle[1] = HIGH_PART (lhs) * LOW_PART (rhs);

  temp = result.low;
  result.low += LOW_PART (middle[0]) << (PART_PRECISION / 2);
  if (result.low < temp)
    result.high++;

  temp = result.low;
  result.low += LOW_PART (middle[1]) << (PART_PRECISION / 2);
  if (result.low < temp)
    result.high++;

  result.high += HIGH_PART (middle[0]);
  result.high += HIGH_PART (middle[1]);
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  result.unsignedp = true;
  result.overflow = false;
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  return result;
}

/* Multiply two preprocessing numbers.  */
static cpp_num
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num_mul (cpp_reader *pfile, cpp_num lhs, cpp_num rhs)
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{
  cpp_num result, temp;
  bool unsignedp = lhs.unsignedp || rhs.unsignedp;
  bool overflow, negate = false;
  size_t precision = CPP_OPTION (pfile, precision);

  /* Prepare for unsigned multiplication.  */
  if (!unsignedp)
    {
      if (!num_positive (lhs, precision))
	negate = !negate, lhs = num_negate (lhs, precision);
      if (!num_positive (rhs, precision))
	negate = !negate, rhs = num_negate (rhs, precision);
    }

  overflow = lhs.high && rhs.high;
  result = num_part_mul (lhs.low, rhs.low);

  temp = num_part_mul (lhs.high, rhs.low);
  result.high += temp.low;
  if (temp.high)
    overflow = true;

  temp = num_part_mul (lhs.low, rhs.high);
  result.high += temp.low;
  if (temp.high)
    overflow = true;

  temp.low = result.low, temp.high = result.high;
  result = num_trim (result, precision);
  if (!num_eq (result, temp))
    overflow = true;

  if (negate)
    result = num_negate (result, precision);

  if (unsignedp)
    result.overflow = false;
  else
    result.overflow = overflow || (num_positive (result, precision) ^ !negate
				   && !num_zerop (result));
  result.unsignedp = unsignedp;

  return result;
}

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/* Divide two preprocessing numbers, LHS and RHS, returning the answer
   or the remainder depending upon OP. LOCATION is the source location
   of this operator (for diagnostics).  */

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static cpp_num
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num_div_op (cpp_reader *pfile, cpp_num lhs, cpp_num rhs, enum cpp_ttype op,
	    source_location location)
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{
  cpp_num result, sub;
  cpp_num_part mask;
  bool unsignedp = lhs.unsignedp || rhs.unsignedp;
  bool negate = false, lhs_neg = false;
  size_t i, precision = CPP_OPTION (pfile, precision);

  /* Prepare for unsigned division.  */
  if (!unsignedp)
    {
      if (!num_positive (lhs, precision))
	negate = !negate, lhs_neg = true, lhs = num_negate (lhs, precision);
      if (!num_positive (rhs, precision))
	negate = !negate, rhs = num_negate (rhs, precision);
    }

  /* Find the high bit.  */
  if (rhs.high)
    {
      i = precision - 1;
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      mask = (cpp_num_part) 1 << (i - PART_PRECISION);
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      for (; ; i--, mask >>= 1)
	if (rhs.high & mask)
	  break;
    }
  else if (rhs.low)
    {
      if (precision > PART_PRECISION)
	i = precision - PART_PRECISION - 1;
      else
	i = precision - 1;
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      mask = (cpp_num_part) 1 << i;
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      for (; ; i--, mask >>= 1)
	if (rhs.low & mask)
	  break;
    }
  else
    {
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      if (!pfile->state.skip_eval)
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	cpp_error_with_line (pfile, CPP_DL_ERROR, location, 0,
			     "division by zero in #if");
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      return lhs;
    }

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  /* First nonzero bit of RHS is bit I.  Do naive division by
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     shifting the RHS fully left, and subtracting from LHS if LHS is
     at least as big, and then repeating but with one less shift.
     This is not very efficient, but is easy to understand.  */

  rhs.unsignedp = true;
  lhs.unsignedp = true;
  i = precision - i - 1;
  sub = num_lshift (rhs, precision, i);

  result.high = result.low = 0;
  for (;;)
    {
      if (num_greater_eq (lhs, sub, precision))
	{
	  lhs = num_binary_op (pfile, lhs, sub, CPP_MINUS);
	  if (i >= PART_PRECISION)
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	    result.high |= (cpp_num_part) 1 << (i - PART_PRECISION);
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	  else
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	    result.low |= (cpp_num_part) 1 << i;
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	}
      if (i-- == 0)
	break;
      sub.low = (sub.low >> 1) | (sub.high << (PART_PRECISION - 1));
      sub.high >>= 1;
    }

  /* We divide so that the remainder has the sign of the LHS.  */
  if (op == CPP_DIV)
    {
      result.unsignedp = unsignedp;
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      result.overflow = false;
      if (!unsignedp)
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	{
	  if (negate)
	    result = num_negate (result, precision);
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	  result.overflow = (num_positive (result, precision) ^ !negate
			     && !num_zerop (result));
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	}

      return result;
    }

  /* CPP_MOD.  */
  lhs.unsignedp = unsignedp;
  lhs.overflow = false;
  if (lhs_neg)
    lhs = num_negate (lhs, precision);

  return lhs;
}
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/* Handle meeting "__has_include__" in a preprocessor expression.  */
static cpp_num
parse_has_include (cpp_reader *pfile, enum include_type type)
{
  cpp_num result;
  bool paren = false;
  cpp_hashnode *node = 0;
  const cpp_token *token;
  bool bracket = false;
  char *fname = 0;

  result.unsignedp = false;
  result.high = 0;
  result.overflow = false;
  result.low = 0;

  pfile->state.in__has_include__++;

  token = cpp_get_token (pfile);
  if (token->type == CPP_OPEN_PAREN)
    {
      paren = true;
      token = cpp_get_token (pfile);
    }

  if (token->type == CPP_STRING || token->type == CPP_HEADER_NAME)
    {
      if (token->type == CPP_HEADER_NAME)
	bracket = true;
      fname = XNEWVEC (char, token->val.str.len - 1);
      memcpy (fname, token->val.str.text + 1, token->val.str.len - 2);
      fname[token->val.str.len - 2] = '\0';
      node = token->val.node.node;
    }
  else if (token->type == CPP_LESS)
    {
      bracket = true;
      fname = _cpp_bracket_include (pfile);
    }
  else
    cpp_error (pfile, CPP_DL_ERROR,
	       "operator \"__has_include__\" requires a header string");

  if (fname)
    {
      int angle_brackets = (bracket ? 1 : 0);

      if (_cpp_has_header (pfile, fname, angle_brackets, type))
	result.low = 1;
      else
	result.low = 0;

      XDELETEVEC (fname);
    }

  if (paren && cpp_get_token (pfile)->type != CPP_CLOSE_PAREN)
    cpp_error (pfile, CPP_DL_ERROR,
	       "missing ')' after \"__has_include__\"");

  /* A possible controlling macro of the form #if !__has_include__ ().
     _cpp_parse_expr checks there was no other junk on the line.  */
  if (node)
    pfile->mi_ind_cmacro = node;

  pfile->state.in__has_include__--;

  return result;
}