sdcc/support/regression/tests/bug-3567.c

   1 /* bug-3255.c
   2    For z80, a read from a pointer overwrote register a that was in use for a local variable.
   3  */
   4
   5 #include <testfwk.h>
   6
   7 // Based on code by "Under4Mhz" licensed under GPL 2.0 or later
   8 #include <stdint.h>
   9
  10 #if !(defined(__SDCC_mcs51) && defined(__SDCC_MODEL_SMALL)) && !defined(__SDCC_pdk14) // Lack of memory
  11 static volatile uint8_t VDPControlPort;
  12 static volatile uint8_t VDPDataPortOut;
  13
  14 #define BYTE_HI(x) ((x)>>8)
  15 #define VDU_ADDRESS_SET_MASK 0x4000
  16
  17 void vdu_stop() {}
  18
  19 #define vdu_next_set_fast(value) VDPDataPortOut = value
  20 #define vdu_address_set_unsafe(address) { VDPControlPort=address; VDPControlPort=BYTE_HI((address) | VDU_ADDRESS_SET_MASK ); }
  21
  22 #define for8( var, size ) for ( unsigned char var = 0; var < size; var++ )
  23 typedef uint8_t u8;
  24 typedef uint16_t u16;
  25
  26 #define MAX_TILES 24
  27
  28 typedef struct {
  29
  30     u16 address;
  31     u8 size;
  32     u8 tile[2];
  33
  34 } GameTile;
  35
  36 typedef struct {
  37
  38     GameTile tiles[MAX_TILES];
  39     u8 size;
  40
  41 } GameTileState;
  42
  43 GameTileState gameTiles = { .size = 2, .tiles = { { 1, 2, { 2, 3 } }, { 6, 2, { 7, 8 } } } };
  44
  45 int p(int i)
  46 {
  47     ASSERT (i == 2);
  48 }
  49
  50 void GameTileCallback() {
  51
  52     vdu_stop();
  53
  54     GameTile *gameTile = gameTiles.tiles;
  55
  56     for8( id, gameTiles.size ) {
  57
  58         vdu_address_set_unsafe( gameTile->address );
  59
  60         u8 *ptr = gameTile->tile;
  61         u8 size; size = gameTile->size;
  62         do {
  63             vdu_next_set_fast( *ptr++ ); // Pointer read here overwrote size, which was allocated to register a.
  64
  65         } while ( --size );
  66
  67         p (ptr - gameTile->tile);
  68
  69         gameTile++;
  70     }
  71
  72     gameTiles.size = 0;
  73 }
  74 #endif
  75
  76 void
  77 testBug(void) {
  78 #if !(defined(__SDCC_mcs51) && defined(__SDCC_MODEL_SMALL)) && !defined(__SDCC_pdk14) // Lack of memory
  79     GameTileCallback();
  80 #endif
  81 }
  82