Return to class.h CVS log

Up to [GCC 2.x] / gcc / cp

Annotation of gcc/cp/class.h, revision 1.1

1.1     ! root        1: /* Variables and structures for overloading rules.
        !             2:    Copyright (C) 1993 Free Software Foundation, Inc.
        !             3: 
        !             4: This file is part of GNU CC.
        !             5: 
        !             6: GNU CC is free software; you can redistribute it and/or modify
        !             7: it under the terms of the GNU General Public License as published by
        !             8: the Free Software Foundation; either version 2, or (at your option)
        !             9: any later version.
        !            10: 
        !            11: GNU CC is distributed in the hope that it will be useful,
        !            12: but WITHOUT ANY WARRANTY; without even the implied warranty of
        !            13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
        !            14: GNU General Public License for more details.
        !            15: 
        !            16: You should have received a copy of the GNU General Public License
        !            17: along with GNU CC; see the file COPYING.  If not, write to
        !            18: the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
        !            19: 
        !            20: /* The following structure is used when comparing various alternatives
        !            21:    for overloading.  The unsigned quantity `strikes.i' is used
        !            22:    for fast comparison of two possibilities.  This number is an
        !            23:    aggregate of four constituents:
        !            24: 
        !            25:      EVIL: if this is non-zero, then the candidate should not be considered
        !            26:      ELLIPSIS: if this is non-zero, then some actual argument has been matched
        !            27:                against an ellipsis
        !            28:      USER: if this is non-zero, then a user-defined type conversion is needed
        !            29:      B_OR_D: if this is non-zero, then use a base pointer instead of the
        !            30:              type of the pointer we started with.
        !            31:      EASY: if this is non-zero, then we have a builtin conversion
        !            32:            (such as int to long, int to float, etc) to do.
        !            33: 
        !            34:    If two candidates require user-defined type conversions, and the
        !            35:    type conversions are not identical, then an ambiguity error
        !            36:    is reported.
        !            37: 
        !            38:    If two candidates agree on user-defined type conversions,
        !            39:    and one uses pointers of strictly higher type (derived where
        !            40:    another uses base), then that alternative is silently chosen.
        !            41: 
        !            42:    Note that this technique really only works for 255 arguments.  Perhaps
        !            43:    this is not enough.  */
        !            44: 
        !            45: /* These macros and harshness_code are used by the NEW METHOD.  */
        !            46: #define EVIL_CODE (1<<7)
        !            47: #define CONST_CODE (1<<6)
        !            48: #define ELLIPSIS_CODE (1<<5)
        !            49: #define USER_CODE (1<<4)
        !            50: #define STD_CODE (1<<3)
        !            51: #define PROMO_CODE (1<<2)
        !            52: #define QUAL_CODE (1<<1)
        !            53: #define TRIVIAL_CODE (1<<0)
        !            54: 
        !            55: struct harshness_code
        !            56: {
        !            57:   /* What kind of conversion is involved.  */
        !            58:   unsigned short code;
        !            59: 
        !            60:   /* The inheritance distance.  */
        !            61:   short distance;
        !            62: 
        !            63:   /* For a PROMO_CODE, Any special penalties involved in integral conversions.
        !            64:      This exists because $4.1 of the ARM states that something like
        !            65:      `short unsigned int' should promote to `int', not `unsigned int'.
        !            66:      If, for example, it tries to match two fns, f(int) and f(unsigned),
        !            67:      f(int) should be a better match than f(unsigned) by this rule.  Without
        !            68:      this extra metric, they both only appear as "integral promotions", which
        !            69:      will lead to an ambiguity.
        !            70:      For a TRIVIAL_CODE, This is also used by build_overload_call_real and
        !            71:      convert_harshness to keep track of other information we need.  */
        !            72:   unsigned short int_penalty;
        !            73: };
        !            74: 
        !            75: struct candidate
        !            76: {
        !            77:   struct harshness_code h;     /* Used for single-argument conversions.  */
        !            78: 
        !            79:   int h_len;                   /* The length of the harshness vector.  */
        !            80: 
        !            81:   tree function;               /* A FUNCTION_DECL */
        !            82:   tree basetypes;              /* The path to function. */
        !            83:   tree arg;                    /* first parm to function.  */
        !            84: 
        !            85:   /* Indexed by argument number, encodes evil, user, d_to_b, and easy
        !            86:      strikes for that argument.  At end of array, we store the index+1
        !            87:      of where we started using default parameters, or 0 if there are
        !            88:      none.  */
        !            89:   struct harshness_code *harshness;
        !            90: 
        !            91:   union
        !            92:     {
        !            93:       tree field;              /* If no evil strikes, the FUNCTION_DECL of
        !            94:                                   the function (if a member function).  */
        !            95:       int bad_arg;             /* the index of the first bad argument:
        !            96:                                   0 if no bad arguments
        !            97:                                   > 0 is first bad argument
        !            98:                                   -1 if extra actual arguments
        !            99:                                   -2 if too few actual arguments.
        !           100:                                   -3 if const/non const method mismatch.
        !           101:                                   -4 if type unification failed.
        !           102:                                   -5 if contravariance violation.  */
        !           103:     } u;
        !           104: };
        !           105: int rank_for_overload ();
        !           106: 
        !           107: /* Variables shared between class.c and call.c.  */
        !           108: 
        !           109: extern int n_vtables;
        !           110: extern int n_vtable_entries;
        !           111: extern int n_vtable_searches;
        !           112: extern int n_vtable_elems;
        !           113: extern int n_convert_harshness;
        !           114: extern int n_compute_conversion_costs;
        !           115: extern int n_build_method_call;
        !           116: extern int n_inner_fields_searched;

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.