scout/disassembler/libc.c

   1 /* Internal tiny implementation of necessary libc functions. */
   2
   3 #include <exec/tasks.h>
   4 #include <proto/exec.h>
   5 #include <sys/types.h>
   6 #include <setjmp.h>
   7 #include <string.h>
   8
   9 #include "libc.h"
  10
  11 /*
  12  * Note that we use tc_UserData in order to store a pointer to our
  13  * data. Since applications may use tc_UserData for their own purpose,
  14  * we save old value upon function entry and restore it upon exit.
  15  * libc_setcontext() and libc_unsetcontext() are responsible for
  16  * doing this.
  17  * I hope this will not clash with some weird stuff (like using tc_UserData
  18  * inside exceptions). In theory it is possible to keep own list of contexts
  19  * and associated tasks, but this would be slow and overcomplicated.
  20  */
  21
  22 static inline struct LibcData *GetLibcData(void)
  23 {
  24     struct Task *me;
  25
  26     me = FindTask(NULL);
  27     return (struct LibcData *)me->tc_UserData;
  28 }
  29
  30 void _abort(char *file, unsigned int line)
  31 {
  32     struct LibcData *ctx = GetLibcData();
  33
  34     ctx->exception_arg1 = file;
  35     ctx->exception_arg2 = line;
  36     longjmp(ctx->abort_buf, EXCEPTION_ABORT);
  37 }
  38
  39 void *calloc(size_t nmemb, size_t size)
  40 {
  41     struct LibcData *data = GetLibcData();
  42
  43     /* Note that this implies that the pool was created with MEMF_CLEAR flag */
  44     return AllocVecPooled(data->pool, nmemb * size);
  45 }
  46
  47 void* xmalloc (size_t size)
  48 {
  49     struct LibcData *data = GetLibcData();
  50     void *mem;
  51
  52     mem = AllocVecPooled(data->pool, size);
  53     if (!mem)
  54         longjmp(data->abort_buf, EXCEPTION_NO_MEMORY);
  55
  56     return mem;
  57 }
  58
  59
  60
  61 void libc_setcontext(struct LibcData *data)
  62 {
  63     struct Task *me = FindTask(NULL);
  64     data->userdata = me->tc_UserData;
  65
  66     me->tc_UserData = data;
  67 }
  68
  69 void libc_unsetcontext(void)
  70 {
  71     struct Task *me = FindTask(NULL);
  72     struct LibcData *data = (struct LibcData *)me->tc_UserData;
  73
  74     me->tc_UserData = data->userdata;
  75 }