sdcc/support/regression/tests/bug-3322.c

   1 /*
   2    bug-3322.c
   3    A z80 code generation (overwriting a value in iy during an assignment) bug found by z88dk
   4    */
   5
   6 #include <testfwk.h>
   7
   8 #define PIECE_IS_NEXT 255
   9
  10 #define STARTBOARD_X 15
  11 #define STARTBOARD_Y 2
  12
  13 #define POS_NEXT_X 3
  14 #define POS_NEXT_Y 1
  15
  16 #define NEXT_X (POS_NEXT_X+2)
  17 #define NEXT_Y (POS_NEXT_Y+3)
  18
  19 #define EMPTY_GR_CHAR  32
  20 #define EMPTY_GR_COLOR 0
  21 #define FONTS 0
  22
  23 typedef unsigned char byte;
  24
  25 // tetromino sprite
  26 typedef struct {
  27    int x;          // signed integers to allow negative board positions
  28    int y;          // -1 means piece is preview ("next")
  29    byte piece;
  30    byte angle;
  31 } sprite;
  32
  33 #define gr4_tile(x,y,tile,color,tileset) _gr4_tile_x = (x); _gr4_tile_y = (y); _gr4_tile_tile = (tile); _gr4_tile_color = (color); _gr4_tile_tileset = (tileset); _gr4_tile()
  34
  35 byte _gr4_tile_x;
  36 byte _gr4_tile_y;
  37 byte _gr4_tile_tile;
  38 byte _gr4_tile_color;
  39 byte *_gr4_tile_tileset;
  40
  41 byte *_gr4_tile_source;
  42 byte *_gr4_tile_dest;
  43
  44 void _gr4_tile() {
  45 }
  46
  47 // offset of a single tile composing a piece
  48 typedef struct {
  49    byte offset_x;
  50    byte offset_y;
  51 } tile_offset;
  52
  53 tile_offset *get_piece_offsets(byte piece, byte angle);
  54
  55 tile_offset pieces_XY[4] = {
  56    {+1,+1}  ,  {+2,+1}  ,  {+3,+1}  ,  {+1,+2}  ,
  57 };
  58
  59 void SLOT1_VIDEO_START() {
  60 }
  61
  62 void SLOT1_END() {
  63 }
  64
  65 // given a piece number and an angle returns the 4 byte "offsets" of the piece
  66 tile_offset *get_piece_offsets(byte piece, byte angle) {
  67    return &pieces_XY[(piece*sizeof(tile_offset)*4*2)+angle*4];
  68 }
  69
  70 void gr_erasepiece(sprite *p);
  71
  72 // erase piece from the screen
  73 void gr_erasepiece(sprite *p) {
  74    tile_offset *data = get_piece_offsets(p->piece, p->angle);   // bug if this declaration is here
  75
  76    int px = p->x;
  77    int py = p->y;
  78
  79    // are we erasing the "next" piece ?
  80    if(py==PIECE_IS_NEXT) {
  81       px = NEXT_X;
  82       py = NEXT_Y;
  83    }
  84    else {
  85       px += STARTBOARD_X;
  86       py += STARTBOARD_Y;
  87    }
  88
  89    // tile_offset *data = get_piece_offsets(p->piece, p->angle);   // no bug if this declaration is here
  90
  91    SLOT1_VIDEO_START();
  92    for(byte t=0; t<4; t++) {
  93       int x = px + data->offset_x;
  94       int y = py + data->offset_y;
  95       data++;
  96       gr4_tile((byte)x,(byte)y,EMPTY_GR_CHAR,EMPTY_GR_COLOR,FONTS);
  97    }
  98    SLOT1_END();
  99 }
 100
 101 void testBug(void)
 102 {
 103    sprite s;
 104
 105    s.x = 0;
 106    s.y = 0;
 107    s.piece = 0;
 108    s.angle = 0;
 109    gr_erasepiece(&s);
 110    ASSERT(_gr4_tile_x == s.x + STARTBOARD_X + pieces_XY[3].offset_x);
 111    ASSERT(_gr4_tile_y == s.y + STARTBOARD_Y + pieces_XY[3].offset_y);
 112 }
 113