sdcc/support/regression/tests/bug-3563.c

   1 /* bug-3563.c
   2    A parameter passing issue in the mcs51 port when using --stack-auto.
   3  */
   4
   5 // According to bug reporter, his reproducing sample code, from which this regression test is derived, was derived from TinyUSb. TinyUSB is under MIT license.
   6
   7 #include <testfwk.h>
   8
   9 #include <stdint.h>
  10 #include <stdbool.h>
  11 #include <string.h>
  12
  13 #if !defined(__SDCC_pdk14) && !defined(__SDCC_pdk15) // Lack of memory
  14 bool check_now;
  15
  16 void my_putchar(char c) {
  17   (void)c;
  18 }
  19
  20 void my_putchar_hex(uint8_t c) {
  21   if (check_now)
  22     ASSERT (!c);
  23 }
  24
  25 void my_puts(char const * s) {
  26   check_now = !strcmp (s, "rd_idx=");
  27 }
  28
  29 typedef struct tu_fifo_t {
  30   uint8_t* buffer          ; // buffer pointer
  31   uint16_t depth           ; // max items
  32
  33   struct {
  34     uint16_t item_size : 15; // size of each item
  35     bool overwritable  : 1 ; // ovwerwritable when full
  36   };
  37
  38   volatile uint16_t wr_idx ; // write index
  39   volatile uint16_t rd_idx ; // read index
  40 } tu_fifo_t;
  41
  42 static inline
  43 uint16_t idx2ptr(uint16_t depth, uint16_t idx)
  44 {
  45   // Only run at most 3 times since index is limit in the range of [0..2*depth)
  46   while ( idx >= depth ) idx -= depth;
  47   return idx;
  48 }
  49
  50 static inline    // WORKAROUND: comment out this line
  51 void _ff_pull(tu_fifo_t* f, void * app_buf, uint16_t rel)
  52 {
  53   // WORKAROUND: move the puts("rel=") line here
  54
  55   memcpy(app_buf, f->buffer + (rel * f->item_size), f->item_size);
  56
  57   my_puts("rel="); my_putchar_hex(rel >> 8); my_putchar_hex(rel & 0xff); my_putchar('\n');
  58   my_puts("app_buf="); my_putchar_hex((uintptr_t)app_buf >> 8); my_putchar_hex((uintptr_t)app_buf & 0xff); my_putchar('\n');
  59 }
  60
  61 static bool _tu_fifo_peek(tu_fifo_t* f, void * p_buffer, uint16_t wr_idx, uint16_t rd_idx)
  62 {
  63   (void)wr_idx;
  64
  65   uint16_t rd_ptr = idx2ptr(f->depth, rd_idx);    // becomes rel inside _ff_pull
  66
  67   // WORKAROUND: move rd_idx line here
  68
  69   // Peek data
  70   _ff_pull(f, p_buffer, rd_ptr);
  71
  72   my_puts("rd_idx="); my_putchar_hex(rd_idx >> 8); my_putchar_hex(rd_idx & 0xff); my_putchar('\n');
  73   my_puts("p_buffer="); my_putchar_hex((uintptr_t)p_buffer >> 8); my_putchar_hex((uintptr_t)p_buffer & 0xff); my_putchar('\n');
  74
  75   return true;
  76 }
  77
  78 uint8_t app_buf[2];
  79
  80 int m(void) {
  81     uint8_t buf[32];
  82
  83     tu_fifo_t fifo = {
  84         .buffer = buf,
  85         .depth = 16,
  86         .item_size = 2,
  87         .wr_idx = 1,
  88         .rd_idx = 0
  89     };
  90
  91     // Here we pass wr_idx = 1, rd_idx=0 but rd_idx will be reported as 0xe21d if you print
  92     // it at any point after the memcpy inside _ff_pull. If you print it before that point,
  93     // or if you remove the "inline" on _ff_pull, the correct value of 0 is printed.
  94
  95     _tu_fifo_peek(&fifo, app_buf, 1, 0);
  96
  97     return 0;
  98 }
  99 #endif
 100
 101 void
 102 testBug (void)
 103 {
 104 #ifndef __SDCC_mcs51 // This bug #3563 is not yet fixed.
 105 #if !defined(__SDCC_pdk14) && !defined(__SDCC_pdk15) // Lack of memory
 106   m ();
 107 #endif
 108 #endif
 109 }
 110