call.c

gcc-2.95.3 Linux下最常用的C编译器

/* 4 For every pair T, VQ), where T is an arithmetic or  enumeration  type,
     and  VQ  is  either  volatile or empty, there exist candidate operator
     functions of the form
	     VQ T&   operator++(VQ T&);
	     T       operator++(VQ T&, int);
   5 For every pair T, VQ), where T is an enumeration type or an arithmetic
     type  other than bool, and VQ is either volatile or empty, there exist
     candidate operator functions of the form
	     VQ T&   operator--(VQ T&);
	     T       operator--(VQ T&, int);
   6 For every pair T, VQ), where T is  a  cv-qualified  or  cv-unqualified
     complete  object type, and VQ is either volatile or empty, there exist
     candidate operator functions of the form
	     T*VQ&   operator++(T*VQ&);
	     T*VQ&   operator--(T*VQ&);
	     T*      operator++(T*VQ&, int);
	     T*      operator--(T*VQ&, int);  */

    case POSTDECREMENT_EXPR:
    case PREDECREMENT_EXPR:
      if (TREE_CODE (type1) == BOOLEAN_TYPE)
	return candidates;
    case POSTINCREMENT_EXPR:
    case PREINCREMENT_EXPR:
      if ((ARITHMETIC_TYPE_P (type1) && TREE_CODE (type1) != ENUMERAL_TYPE)
	  || TYPE_PTROB_P (type1))
	{
	  type1 = build_reference_type (type1);
	  break;
	}
      return candidates;

/* 7 For every cv-qualified or cv-unqualified complete object type T, there
     exist candidate operator functions of the form

	     T&      operator*(T*);

   8 For every function type T, there exist candidate operator functions of
     the form
	     T&      operator*(T*);  */

    case INDIRECT_REF:
      if (TREE_CODE (type1) == POINTER_TYPE
	  && (TYPE_PTROB_P (type1)
	      || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE))
	break;
      return candidates;

/* 9 For every type T, there exist candidate operator functions of the form
	     T*      operator+(T*);

   10For  every  promoted arithmetic type T, there exist candidate operator
     functions of the form
	     T       operator+(T);
	     T       operator-(T);  */

    case CONVERT_EXPR: /* unary + */
      if (TREE_CODE (type1) == POINTER_TYPE
	  && TREE_CODE (TREE_TYPE (type1)) != OFFSET_TYPE)
	break;
    case NEGATE_EXPR:
      if (ARITHMETIC_TYPE_P (type1))
	break;
      return candidates;

/* 11For every promoted integral type T,  there  exist  candidate  operator
     functions of the form
	     T       operator~(T);  */

    case BIT_NOT_EXPR:
      if (INTEGRAL_TYPE_P (type1))
	break;
      return candidates;

/* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
     is the same type as C2 or is a derived class of C2, T  is  a  complete
     object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
     there exist candidate operator functions of the form
	     CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
     where CV12 is the union of CV1 and CV2.  */

    case MEMBER_REF:
      if (TREE_CODE (type1) == POINTER_TYPE
	  && (TYPE_PTRMEMFUNC_P (type2) || TYPE_PTRMEM_P (type2)))
	{
	  tree c1 = TREE_TYPE (type1);
	  tree c2 = (TYPE_PTRMEMFUNC_P (type2)
		     ? TYPE_METHOD_BASETYPE (TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (type2)))
		     : TYPE_OFFSET_BASETYPE (TREE_TYPE (type2)));

	  if (IS_AGGR_TYPE (c1) && DERIVED_FROM_P (c2, c1)
	      && (TYPE_PTRMEMFUNC_P (type2)
		  || is_complete (TREE_TYPE (TREE_TYPE (type2)))))
	    break;
	}
      return candidates;

/* 13For every pair of promoted arithmetic types L and R, there exist  can-
     didate operator functions of the form
	     LR      operator*(L, R);
	     LR      operator/(L, R);
	     LR      operator+(L, R);
	     LR      operator-(L, R);
	     bool    operator<(L, R);
	     bool    operator>(L, R);
	     bool    operator<=(L, R);
	     bool    operator>=(L, R);
	     bool    operator==(L, R);
	     bool    operator!=(L, R);
     where  LR  is  the  result of the usual arithmetic conversions between
     types L and R.

   14For every pair of types T and I, where T  is  a  cv-qualified  or  cv-
     unqualified  complete  object  type and I is a promoted integral type,
     there exist candidate operator functions of the form
	     T*      operator+(T*, I);
	     T&      operator[](T*, I);
	     T*      operator-(T*, I);
	     T*      operator+(I, T*);
	     T&      operator[](I, T*);

   15For every T, where T is a pointer to complete object type, there exist
     candidate operator functions of the form112)
	     ptrdiff_t operator-(T, T);

   16For  every pointer type T, there exist candidate operator functions of
     the form
	     bool    operator<(T, T);
	     bool    operator>(T, T);
	     bool    operator<=(T, T);
	     bool    operator>=(T, T);
	     bool    operator==(T, T);
	     bool    operator!=(T, T);

   17For every pointer to member type T,  there  exist  candidate  operator
     functions of the form
	     bool    operator==(T, T);
	     bool    operator!=(T, T);  */

    case MINUS_EXPR:
      if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2))
	break;
      if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
	{
	  type2 = ptrdiff_type_node;
	  break;
	}
    case MULT_EXPR:
    case TRUNC_DIV_EXPR:
      if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
	break;
      return candidates;

    case EQ_EXPR:
    case NE_EXPR:
      if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
	  || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2)))
	break;
      if ((TYPE_PTRMEMFUNC_P (type1) || TYPE_PTRMEM_P (type1))
	  && null_ptr_cst_p (args[1]))
	{
	  type2 = type1;
	  break;
	}
      if ((TYPE_PTRMEMFUNC_P (type2) || TYPE_PTRMEM_P (type2))
	  && null_ptr_cst_p (args[0]))
	{
	  type1 = type2;
	  break;
	}
    case LT_EXPR:
    case GT_EXPR:
    case LE_EXPR:
    case GE_EXPR:
    case MAX_EXPR:
    case MIN_EXPR:
      if ((ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
	  || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)))
	break;
      if (TYPE_PTR_P (type1) && null_ptr_cst_p (args[1]))
	{
	  type2 = type1;
	  break;
	}
      if (null_ptr_cst_p (args[0]) && TYPE_PTR_P (type2))
	{
	  type1 = type2;
	  break;
	}
      return candidates;

    case PLUS_EXPR:
      if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
	break;
    case ARRAY_REF:
      if (INTEGRAL_TYPE_P (type1) && TYPE_PTROB_P (type2))
	{
	  type1 = ptrdiff_type_node;
	  break;
	}
      if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
	{
	  type2 = ptrdiff_type_node;
	  break;
	}
      return candidates;

/* 18For  every pair of promoted integral types L and R, there exist candi-
     date operator functions of the form
	     LR      operator%(L, R);
	     LR      operator&(L, R);
	     LR      operator^(L, R);
	     LR      operator|(L, R);
	     L       operator<<(L, R);
	     L       operator>>(L, R);
     where LR is the result of the  usual  arithmetic  conversions  between
     types L and R.  */

    case TRUNC_MOD_EXPR:
    case BIT_AND_EXPR:
    case BIT_IOR_EXPR:
    case BIT_XOR_EXPR:
    case LSHIFT_EXPR:
    case RSHIFT_EXPR:
      if (INTEGRAL_TYPE_P (type1) && INTEGRAL_TYPE_P (type2))
	break;
      return candidates;

/* 19For  every  triple  L, VQ, R), where L is an arithmetic or enumeration
     type, VQ is either volatile or empty, and R is a  promoted  arithmetic
     type, there exist candidate operator functions of the form
	     VQ L&   operator=(VQ L&, R);
	     VQ L&   operator*=(VQ L&, R);
	     VQ L&   operator/=(VQ L&, R);
	     VQ L&   operator+=(VQ L&, R);
	     VQ L&   operator-=(VQ L&, R);

   20For  every  pair T, VQ), where T is any type and VQ is either volatile
     or empty, there exist candidate operator functions of the form
	     T*VQ&   operator=(T*VQ&, T*);

   21For every pair T, VQ), where T is a pointer to member type and  VQ  is
     either  volatile or empty, there exist candidate operator functions of
     the form
	     VQ T&   operator=(VQ T&, T);

   22For every triple  T,  VQ,  I),  where  T  is  a  cv-qualified  or  cv-
     unqualified  complete object type, VQ is either volatile or empty, and
     I is a promoted integral type, there exist  candidate  operator  func-
     tions of the form
	     T*VQ&   operator+=(T*VQ&, I);
	     T*VQ&   operator-=(T*VQ&, I);

   23For  every  triple  L,  VQ,  R), where L is an integral or enumeration
     type, VQ is either volatile or empty, and R  is  a  promoted  integral
     type, there exist candidate operator functions of the form

	     VQ L&   operator%=(VQ L&, R);
	     VQ L&   operator<<=(VQ L&, R);
	     VQ L&   operator>>=(VQ L&, R);
	     VQ L&   operator&=(VQ L&, R);
	     VQ L&   operator^=(VQ L&, R);
	     VQ L&   operator|=(VQ L&, R);  */

    case MODIFY_EXPR:
      switch (code2)
	{
	case PLUS_EXPR:
	case MINUS_EXPR:
	  if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
	    {
	      type2 = ptrdiff_type_node;
	      break;
	    }
	case MULT_EXPR:
	case TRUNC_DIV_EXPR:
	  if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
	    break;
	  return candidates;

	case TRUNC_MOD_EXPR:
	case BIT_AND_EXPR:
	case BIT_IOR_EXPR:
	case BIT_XOR_EXPR:
	case LSHIFT_EXPR:
	case RSHIFT_EXPR:
	  if (INTEGRAL_TYPE_P (type1) && INTEGRAL_TYPE_P (type2))
	    break;
	  return candidates;

	case NOP_EXPR:
	  if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
	    break;
	  if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
	      || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
	      || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
	      || ((TYPE_PTRMEMFUNC_P (type1)
		   || TREE_CODE (type1) == POINTER_TYPE)
		  && null_ptr_cst_p (args[1])))
	    {
	      type2 = type1;
	      break;
	    }
	  return candidates;

	default:
	  my_friendly_abort (367);
	}
      type1 = build_reference_type (type1);
      break;

    case COND_EXPR:
      /* Kludge around broken overloading rules whereby
	 bool ? const char& : enum is ambiguous
	 (between int and const char&).  */
      flags |= LOOKUP_NO_TEMP_BIND;

      /* Extension: Support ?: of enumeral type.  Hopefully this will not
         be an extension for long.  */
      if (TREE_CODE (type1) == ENUMERAL_TYPE && type1 == type2)
	break;
      else if (TREE_CODE (type1) == ENUMERAL_TYPE
	       || TREE_CODE (type2) == ENUMERAL_TYPE)
	return candidates;
      if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
	break;
      if (TREE_CODE (type1) == TREE_CODE (type2)
	  && (TREE_CODE (type1) == REFERENCE_TYPE
	      || TREE_CODE (type1) == POINTER_TYPE
	      || TYPE_PTRMEMFUNC_P (type1)
	      || IS_AGGR_TYPE (type1)))
	break;
      if (TREE_CODE (type1) == REFERENCE_TYPE
	  || TREE_CODE (type2) == REFERENCE_TYPE)
	return candidates;
      if (((TYPE_PTRMEMFUNC_P (type1) || TREE_CODE (type1) == POINTER_TYPE)
	   && null_ptr_cst_p (args[1]))
	  || IS_AGGR_TYPE (type1))
	{
	  type2 = type1;
	  break;
	}
      if (((TYPE_PTRMEMFUNC_P (type2) || TREE_CODE (type2) == POINTER_TYPE)
	   && null_ptr_cst_p (args[0]))
	  || IS_AGGR_TYPE (type2))
	{
	  type1 = type2;
	  break;
	}
      return candidates;

    default:
      my_friendly_abort (367);
    }

  /* If we're dealing with two pointer types, we need candidates
     for both of them.  */
  if (type2 && type1 != type2
      && TREE_CODE (type1) == TREE_CODE (type2)
      && (TREE_CODE (type1) == REFERENCE_TYPE
	  || (TREE_CODE (type1) == POINTER_TYPE
	      && TYPE_PTRMEM_P (type1) == TYPE_PTRMEM_P (type2))
	  || TYPE_PTRMEMFUNC_P (type1)
	  || IS_AGGR_TYPE (type1)))
    {
      candidates = build_builtin_candidate
	(candidates, fnname, type1, type1, args, argtypes, flags);
      return build_builtin_candidate
	(candidates, fnname, type2, type2, args, argtypes, flags);
    }

  return build_builtin_candidate
    (candidates, fnname, type1, type2, args, argtypes, flags);
}

tree
type_decays_to (type)
     tree type;
{
  if (TREE_CODE (type) == ARRAY_TYPE)
    return build_pointer_type (TREE_TYPE (type));
  if (TREE_CODE (type) == FUNCTION_TYPE)
    return build_pointer_type (type);
  return type;
}

/* There are three conditions of builtin candidates:

   1) bool-taking candidates.  These are the same regardless of the input.
   2) pointer-pair taking candidates.  These are generated for each type
      one of the input types converts to.
   3) arithmetic candidates.  According to the WP, we should generate
      all of these, but I'm trying not to... */

static struct z_candidate *
add_builtin_candidates (candidates, code, code2, fnname, args, flags)
     struct z_candidate *candidates;
     enum tree_code code, code2;
     tree fnname, *args;
     int flags;
{
  int ref1, i;
  tree type, argtypes[3], types[2];

  for (i = 0; i < 3; ++i)
    {
      if (args[i])
	argtypes[i]  = lvalue_type (args[i]);
      else
	argtypes[i] = NULL_TREE;
    }

  switch (code)
    {
/* 4 For every pair T, VQ), where T is an arithmetic or  enumeration  type,
     and  VQ  is  either  volatile or empty, there exist candidate operator
     functions of the form
		 VQ T&   operator++(VQ T&);  */

    case POSTINCREMENT_EXPR:
    case PREINCREMENT_EXPR:
    case POSTDECREMENT_EXPR:
    case PREDECREMENT_EXPR:
    case MODIFY_EXPR:
      ref1 = 1;
      break;

/* 24There also exist candidate operator functions of the form
	     bool    operator!(bool);
	     bool    operator&&(bool, bool);
	     bool    operator||(bool, bool);  */

    case TRUTH_NOT_EXPR:
      return build_builtin_candidate
	(candidates, fnname, boolean_type_node,
	 NULL_TREE, args, argtypes, flags);

    case TRUTH_ORIF_EXPR:
    case TRUTH_ANDIF_EXPR:
      return build_builtin_candidate
	(candidates, fnname, boolean_type_node,
	 boolean_type_node, args, argtypes, flags);

    case ADDR_EXPR:
    case COMPOUND_EXPR:
    case COMPONENT_REF:
      return candidates;

    default:
      ref1 = 0;