compiler/include/dos/bptr.h

   1 #ifndef DOS_BPTR_H
   2 #define DOS_BPTR_H
   3
   4 /*
   5     Copyright © 1995-2007, The AROS Development Team. All rights reserved.
   6     $Id$
   7
   8     Desc: AROS version of BPTRs
   9     Lang: english
  10 */
  11
  12 #ifndef EXEC_TYPES_H
  13 #   include <exec/types.h>
  14 #endif
  15
  16
  17 #ifndef AROS_BPTR_TYPE
  18 #   ifdef AROS_FAST_BPTR
  19 #       define AROS_BPTR_TYPE   APTR
  20 #   else
  21 #       define AROS_BPTR_TYPE   IPTR
  22 #   endif
  23 #endif
  24 #ifndef AROS_BSTR_TYPE
  25 #   ifdef AROS_FAST_BSTR
  26 #       define AROS_BSTR_TYPE   STRPTR
  27 #   else
  28 #       define AROS_BSTR_TYPE   IPTR
  29 #   endif
  30 #endif
  31
  32 typedef AROS_BPTR_TYPE BPTR;
  33 typedef AROS_BSTR_TYPE BSTR;
  34
  35 /* In the BCPL language memory is addressed in chunks of long (e.g. 32 bit) and also
  36  * the BPTRs on used by DOS on amigaos used this addressing. This is contrary to byte
  37  * (e.g. 8 bit) addressing as is common now for most architectures.
  38  *
  39  * AROS can be configured to have BPTRs also use byte addressing by setting the
  40  * AROS_FAST_BPTR preprocessor symbol in the cpu.h file.
  41  * For source code compatibility AROS__FAST_BPTR should only be used for non-standard
  42  * AROS implementations.
  43  *
  44  * MKBADDR and BADDR macros are defined to access BPTRs in an implementation
  45  * independent way.
  46 */
  47 #ifdef AROS_FAST_BPTR
  48 #   define MKBADDR(a)               ((BPTR)(a))
  49 #   define BADDR(a)                 ((APTR)a)
  50 #   define BNULL                    (NULL)
  51 #else
  52 #   define MKBADDR(a)               ((BPTR)(((IPTR)a)>>2))
  53 #   define BADDR(a)                 ((APTR)(((IPTR)a)<<2))
  54 #   define BNULL                    (0)
  55 #endif
  56
  57 /* BCPL strings used the first byte as the length of the string followed by the string.
  58  * Strings then also had a maximum length of 255. The normal C convention is to have
  59  * strings of any length but ended with a byte value of 0
  60  *
  61  * AROS can be configured to have BSTRs implemented as C strings by setting the
  62  * AROS_FAST_BSTR preprocessor symbol in the cpu.h file.
  63  * For source code compatibility AROS_FAST_BSTR should only be used for non-standard
  64  * AROS implementations.
  65  *
  66  * The AROS_BSTR_ADDR, AROS_BSTR_strlen, AROS_BSTR_setstrlen and AROS_BSTR_MEMSIZE4LEN
  67  * preprocessor macros are provided to work with BSTRs in an implementation independent
  68  * way.
  69  */
  70 #ifdef AROS_FAST_BSTR
  71 #   define AROS_BSTR_ADDR(s)        ((STRPTR)BADDR(s))
  72 #   define AROS_BSTR_strlen(s)      (strlen(AROS_BSTR_ADDR(s)))
  73 #   define AROS_BSTR_setstrlen(s,l) (AROS_BSTR_ADDR(s)[l] = 0)
  74 #   define AROS_BSTR_MEMSIZE4LEN(l) ((l)+1)
  75 #else
  76 #   define AROS_BSTR_ADDR(s)        (((STRPTR)BADDR(s))+1)
  77 #   define AROS_BSTR_strlen(s)      (AROS_BSTR_ADDR(s)[-1])
  78 #   define AROS_BSTR_setstrlen(s,l) do { \
  79     STRPTR _s = AROS_BSTR_ADDR(s); \
  80     _s[-1] = l; \
  81     _s[l]=0; \
  82 } while(0)
  83 #   define AROS_BSTR_MEMSIZE4LEN(l) ((l)+2)
  84 #endif
  85 #define AROS_BSTR_getchar(s,l)   (AROS_BSTR_ADDR(s)[l])
  86 #define AROS_BSTR_putchar(s,l,c) (AROS_BSTR_ADDR(s)[l] = c)
  87
  88 /* Convenience macro for declaring const BSTRs
  89  */
  90 #ifdef AROS_FAST_BSTR
  91 #define AROS_CONST_BSTR(string) ((BSTR)MKBADDR(string))
  92 #else
  93 #define AROS_CONST_BSTR(string) ({ \
  94     static const struct { UBYTE len; UBYTE str[sizeof(string)]; } \
  95         const __tmp_bstr __attribute__((__aligned__(4)))= { .len = sizeof(string)-1, .str = string }; \
  96     (BSTR)MKBADDR(&__tmp_bstr);})
  97 #endif
  98
  99 #endif /* DOS_BPTR_H */