git.sur5r.net Git - cc65/blob - ca65/strexpr.c

   1 /*****************************************************************************/
   2 /*                                                                           */
   3 /*                                 strexpr.c                                 */
   4 /*                                                                           */
   5 /*              String expressions for the ca65 macroassembler               */
   6 /*                                                                           */
   7 /*                                                                           */
   8 /*                                                                           */
   9 /* (C) 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 <stdio.h>
  37
  38 #include "error.h"
  39 #include "expr.h"
  40 #include "scanner.h"
  41 #include "strexpr.h"
  42
  43
  44
  45 /*****************************************************************************/
  46 /*                                   Code                                    */
  47 /*****************************************************************************/
  48
  49
  50
  51 const char* StringExpression (void)
  52 /* Evaluate a string expression. If there are no errors, the function will
  53  * place the string into the token attribute buffer SVal and the token will
  54  * be TOK_STRCON. A pointer to the buffer is returned.
  55  * If there was an error, a NULL pointer is returned.
  56  */
  57 {
  58     char Buf [sizeof (SVal)];
  59
  60     /* Check for a string constant or a function that returns a string */
  61     switch (Tok) {
  62
  63         case TOK_STRING:
  64             NextTok ();
  65             ConsumeLParen ();
  66             if (Tok == TOK_IDENT) {
  67                 /* Save the identifier, then skip it */
  68                 strcpy (Buf, SVal);
  69                 NextTok ();
  70             } else {
  71                 /* Numeric expression */
  72                 long Val = ConstExpression ();
  73                 sprintf (Buf, "%ld", Val);
  74             }
  75             if (Tok != TOK_RPAREN) {
  76                 Error (ERR_RPAREN_EXPECTED);
  77             }
  78             /* Overwrite the token, do not skip it! */
  79             strcpy (SVal, Buf);
  80             Tok = TOK_STRCON;
  81             break;
  82
  83         case TOK_STRCON:
  84             /* We already have a string */
  85             break;
  86
  87         default:
  88             /* Error - no string constant */
  89             return 0;
  90     }
  91
  92     /* Return a pointer to the buffer */
  93     return SVal;
  94 }
  95
  96
  97