git.sur5r.net Git - cc65/blob - src/ca65/ea.c

   1 /*****************************************************************************/
   2 /*                                                                           */
   3 /*                                   ea.c                                    */
   4 /*                                                                           */
   5 /*           Effective address parsing for the ca65 macroassembler           */
   6 /*                                                                           */
   7 /*                                                                           */
   8 /*                                                                           */
   9 /* (C) 1998-2000 Ullrich von Bassewitz                                       */
  10 /*               Wacholderweg 14                                             */
  11 /*               D-70597 Stuttgart                                           */
  12 /* EMail:        uz@musoftware.de                                            */
  13 /*                                                                           */
  14 /*                                                                           */
  15 /* This software is provided 'as-is', without any expressed or implied       */
  16 /* warranty.  In no event will the authors be held liable for any damages    */
  17 /* arising from the use of this software.                                    */
  18 /*                                                                           */
  19 /* Permission is granted to anyone to use this software for any purpose,     */
  20 /* including commercial applications, and to alter it and redistribute it    */
  21 /* freely, subject to the following restrictions:                            */
  22 /*                                                                           */
  23 /* 1. The origin of this software must not be misrepresented; you must not   */
  24 /*    claim that you wrote the original software. If you use this software   */
  25 /*    in a product, an acknowledgment in the product documentation would be  */
  26 /*    appreciated but is not required.                                       */
  27 /* 2. Altered source versions must be plainly marked as such, and must not   */
  28 /*    be misrepresented as being the original software.                      */
  29 /* 3. This notice may not be removed or altered from any source              */
  30 /*    distribution.                                                          */
  31 /*                                                                           */
  32 /*****************************************************************************/
  33
  34
  35
  36 #include "error.h"
  37 #include "expr.h"
  38 #include "instr.h"
  39 #include "scanner.h"
  40 #include "ea.h"
  41
  42
  43
  44 /*****************************************************************************/
  45 /*                                   Code                                    */
  46 /*****************************************************************************/
  47
  48
  49
  50 void GetEA (unsigned long* AddrMode, ExprNode** Expr, ExprNode** Bank)
  51 /* Parse an effective address, return the possible modes in AddrMode, and the
  52  * expression involved (if any) in Expr.
  53  */
  54 {
  55     /* Clear the expressions */
  56     *Bank = *Expr = 0;
  57
  58
  59     if (Tok == TOK_SEP) {
  60
  61         *AddrMode = AM_IMPLICIT;
  62
  63     } else if (Tok == TOK_HASH) {
  64
  65         /* #val */
  66         NextTok ();
  67         *Expr = Expression ();
  68         *AddrMode = AM_IMM;
  69
  70     } else if (Tok == TOK_A) {
  71
  72         NextTok ();
  73         *AddrMode = AM_ACCU;
  74
  75     } else if (Tok == TOK_LBRACK) {
  76
  77         /* [dir] or [dir],y */
  78         NextTok ();
  79         *Expr = Expression ();
  80         Consume (TOK_RBRACK, ERR_RBRACK_EXPECTED);
  81         if (Tok == TOK_COMMA) {
  82             /* [dir],y */
  83             NextTok ();
  84             Consume (TOK_Y, ERR_Y_EXPECTED);
  85             *AddrMode = AM_DIR_IND_LONG_Y;
  86         } else {
  87             /* [dir] */
  88             *AddrMode = AM_DIR_IND_LONG;
  89         }
  90
  91     } else if (Tok == TOK_LPAREN) {
  92
  93         /* One of the indirect modes */
  94         NextTok ();
  95         *Expr = Expression ();
  96
  97         if (Tok == TOK_COMMA) {
  98
  99             /* (expr,X) or (rel,S),y */
 100             NextTok ();
 101             if (Tok == TOK_X) {
 102                 /* (adr,x) */
 103                 NextTok ();
 104                 *AddrMode = AM_ABS_X_IND | AM_DIR_X_IND;
 105                 ConsumeRParen ();
 106             } else if (Tok == TOK_S) {
 107                 /* (rel,s),y */
 108                 NextTok ();
 109                 *AddrMode = AM_STACK_REL_IND_Y;
 110                 ConsumeRParen ();
 111                 ConsumeComma ();
 112                 Consume (TOK_Y, ERR_Y_EXPECTED);
 113             } else {
 114                 Error (ERR_SYNTAX);
 115             }
 116
 117         } else {
 118
 119             /* (adr) or (adr),y */
 120             ConsumeRParen ();
 121             if (Tok == TOK_COMMA) {
 122                 /* (adr),y */
 123                 NextTok ();
 124                 Consume (TOK_Y, ERR_Y_EXPECTED);
 125                 *AddrMode = AM_DIR_IND_Y;
 126             } else {
 127                 /* (adr) */
 128                 *AddrMode = AM_ABS_IND | AM_DIR_IND;
 129             }
 130         }
 131
 132     } else {
 133
 134         /* Remaining stuff:
 135          *
 136          * adr
 137          * bank.adr
 138          * adr,x
 139          * bank.adr,x
 140          * adr,y
 141          * adr,s
 142          */
 143         *Expr = Expression ();
 144
 145         if (Tok == TOK_DOT) {
 146
 147             /* Expr was a bank specification: bank.adr or bank.adr,x */
 148             *Bank = *Expr;
 149             NextTok ();
 150             *Expr = Expression ();
 151             if (Tok == TOK_COMMA) {
 152                 /* bank.adr,x */
 153                 NextTok ();
 154                 Consume (TOK_X, ERR_X_EXPECTED);
 155                 *AddrMode = AM_ABS_LONG_X;
 156             } else {
 157                 /* bank.adr */
 158                 *AddrMode = AM_ABS_LONG;
 159             }
 160
 161         } else {
 162
 163             if (Tok == TOK_COMMA) {
 164
 165                 NextTok ();
 166                 switch (Tok) {
 167
 168                     case TOK_X:
 169                         *AddrMode = AM_ABS_X | AM_DIR_X;
 170                         NextTok ();
 171                         break;
 172
 173                     case TOK_Y:
 174                         *AddrMode = AM_ABS_Y | AM_DIR_Y;
 175                         NextTok ();
 176                         break;
 177
 178                     case TOK_S:
 179                         *AddrMode = AM_STACK_REL;
 180                         NextTok ();
 181                         break;
 182
 183                     default:
 184                         Error (ERR_SYNTAX);
 185
 186                 }
 187
 188             } else {
 189
 190                 *AddrMode = AM_ABS | AM_DIR;
 191
 192             }
 193         }
 194     }
 195 }
 196
 197
 198