Fix UBSAN issues, run it on CI

ankith26 · ankith26 · commit 333f3bb31169 · 2025-06-10T00:17:13.000+05:30
diff --git a/.github/workflows/run-ubuntu-checks.yml b/.github/workflows/run-ubuntu-checks.yml
@@ -101,7 +101,7 @@ jobs:
       id: build-pygame-ce
       run: |
         pyenv global ${{ matrix.python }}-debug
-        python dev.py build --lax --coverage
+        python dev.py build --lax --coverage --sanitize undefined
 
     - name: Run tests
       env:
diff --git a/src_c/SDL_gfx/SDL_gfxPrimitives.c b/src_c/SDL_gfx/SDL_gfxPrimitives.c
@@ -2782,7 +2782,7 @@ _aalineColor(SDL_Surface *dst, Sint16 x1, Sint16 y1, Sint16 x2, Sint16 y2,
         /*
          * Not-so-portable version: erradj = ((Uint64)dx << 32) / (Uint64)dy;
          */
-        erradj = ((dx << 16) / dy) << 16;
+        erradj = (Uint32)((dx << 16) / dy) << 16;
 
         /*
          * draw all pixels other than the first and last
@@ -2819,7 +2819,7 @@ _aalineColor(SDL_Surface *dst, Sint16 x1, Sint16 y1, Sint16 x2, Sint16 y2,
         /*
          * Not-so-portable version: erradj = ((Uint64)dy << 32) / (Uint64)dx;
          */
-        erradj = ((dy << 16) / dx) << 16;
+        erradj = (Uint32)((dy << 16) / dx) << 16;
 
         /*
          * draw all pixels other than the first and last
diff --git a/src_c/alphablit.c b/src_c/alphablit.c
@@ -2448,7 +2448,7 @@ alphablit_alpha(SDL_BlitInfo *info)
     int srcbpp = PG_FORMAT_BytesPerPixel(srcfmt);
     int dstbpp = PG_FORMAT_BytesPerPixel(dstfmt);
     Uint8 dR, dG, dB, dA, sR, sG, sB, sA;
-    int dRi, dGi, dBi, dAi, sRi, sGi, sBi, sAi;
+    Uint32 dRi, dGi, dBi, dAi, sRi, sGi, sBi, sAi;
     Uint32 modulateA = info->src_blanket_alpha;
     Uint32 pixel;
 
diff --git a/src_c/color.c b/src_c/color.c
@@ -1737,7 +1737,7 @@ _color_inv(pgColorObject *color)
 static PyObject *
 _color_int(pgColorObject *color)
 {
-    Uint32 tmp = (color->data[0] << 24) + (color->data[1] << 16) +
+    Uint32 tmp = ((Uint32)color->data[0] << 24) + (color->data[1] << 16) +
                  (color->data[2] << 8) + color->data[3];
     return PyLong_FromUnsignedLong(tmp);
 }
@@ -1748,7 +1748,7 @@ _color_int(pgColorObject *color)
 static PyObject *
 _color_float(pgColorObject *color)
 {
-    Uint32 tmp = ((color->data[0] << 24) + (color->data[1] << 16) +
+    Uint32 tmp = (((Uint32)color->data[0] << 24) + (color->data[1] << 16) +
                   (color->data[2] << 8) + color->data[3]);
     return PyFloat_FromDouble((double)tmp);
 }
diff --git a/src_c/freetype/ft_wrap.h b/src_c/freetype/ft_wrap.h
@@ -41,8 +41,8 @@
 #define FX6_TRUNC(x) ((x) >> 6)
 #define FX16_CEIL_TO_FX6(x) (((x) + 1023L) >> 10)
 #define FX16_ROUND_TO_INT(x) (((x) + 32768L) >> 16)
-#define INT_TO_FX6(i) ((FT_Fixed)((i) << 6))
-#define INT_TO_FX16(i) ((FT_Fixed)((i) << 16))
+#define INT_TO_FX6(i) ((FT_Fixed)((unsigned long long)(i) << 6))
+#define INT_TO_FX16(i) ((FT_Fixed)((unsigned long long)(i) << 16))
 #define FX16_TO_DBL(x) ((x) * 1.52587890625e-5 /* 2.0^-16 */)
 #define DBL_TO_FX16(d) ((FT_Fixed)((d) * 65536.0))
 #define FX6_TO_DBL(x) ((x) * 1.5625e-2 /* 2.0^-6 */)
diff --git a/src_c/mask.c b/src_c/mask.c
@@ -763,7 +763,8 @@ set_pixel_color(Uint8 *pixel, Uint8 bpp, Uint32 color)
 
         case 3:
 #if SDL_BYTEORDER == SDL_LIL_ENDIAN
-            *(Uint16 *)pixel = color;
+            pixel[0] = color;
+            pixel[1] = color >> 8;
             pixel[2] = color >> 16;
 #else  /* != SDL_LIL_ENDIAN */
             pixel[2] = color;
diff --git a/src_c/pixelcopy.c b/src_c/pixelcopy.c
@@ -734,7 +734,7 @@ array_to_surface(PyObject *self, PyObject *arg)
             else {
                 Uint32 alpha = 0;
                 if (format->Amask) {
-                    alpha = 255 >> Aloss << Ashift;
+                    alpha = 255u >> Aloss << Ashift;
                 }
                 switch (view_p->itemsize) {
                     case sizeof(Uint8):
diff --git a/src_c/rotozoom.c b/src_c/rotozoom.c
@@ -236,8 +236,8 @@ transformSurfaceRGBA(SDL_Surface *src, SDL_Surface *dst, int cx, int cy,
     /*
      * Variable setup
      */
-    xd = ((src->w - dst->w) << 15);
-    yd = ((src->h - dst->h) << 15);
+    xd = ((unsigned long long)(src->w - dst->w) << 15);
+    yd = ((unsigned long long)(src->h - dst->h) << 15);
     ax = (cx << 16) - (icos * cx);
     ay = (cy << 16) - (isin * cx);
     sw = src->w - 1;
diff --git a/src_c/surface.c b/src_c/surface.c
@@ -717,16 +717,16 @@ surface_init(pgSurfaceObject *self, PyObject *args, PyObject *kwds)
         if (flags & PGS_SRCALPHA) {
             switch (bpp) {
                 case 16:
-                    Rmask = 0xF << 8;
-                    Gmask = 0xF << 4;
-                    Bmask = 0xF;
-                    Amask = 0xF << 12;
+                    Rmask = 0xFu << 8;
+                    Gmask = 0xFu << 4;
+                    Bmask = 0xFu;
+                    Amask = 0xFu << 12;
                     break;
                 case 32:
-                    Rmask = 0xFF << 16;
-                    Gmask = 0xFF << 8;
-                    Bmask = 0xFF;
-                    Amask = 0xFF << 24;
+                    Rmask = 0xFFu << 16;
+                    Gmask = 0xFFu << 8;
+                    Bmask = 0xFFu;
+                    Amask = 0xFFu << 24;
                     break;
                 default:
                     PyErr_SetString(
@@ -793,20 +793,20 @@ surface_init(pgSurfaceObject *self, PyObject *args, PyObject *kwds)
         if (flags & PGS_SRCALPHA) {
             switch (bpp) {
                 case 16:
-                    Rmask = 0xF << 8;
-                    Gmask = 0xF << 4;
-                    Bmask = 0xF;
-                    Amask = 0xF << 12;
+                    Rmask = 0xFu << 8;
+                    Gmask = 0xFu << 4;
+                    Bmask = 0xFu;
+                    Amask = 0xFu << 12;
                     break;
                 case 24:
                     bpp = 32;
                     // we automatically step up to 32 if video is 24, fall
                     // through to case below
                 case 32:
-                    Rmask = 0xFF << 16;
-                    Gmask = 0xFF << 8;
-                    Bmask = 0xFF;
-                    Amask = 0xFF << 24;
+                    Rmask = 0xFFu << 16;
+                    Gmask = 0xFFu << 8;
+                    Bmask = 0xFFu;
+                    Amask = 0xFFu << 24;
                     break;
                 default:
                     PyErr_SetString(
diff --git a/src_c/surface.h b/src_c/surface.h
@@ -142,22 +142,22 @@
     }
 #endif
 
-#define CREATE_PIXEL(buf, r, g, b, a, bp, ft)                 \
-    switch (bp) {                                             \
-        case 2:                                               \
-            *((Uint16 *)(buf)) =                              \
-                ((r >> PG_FORMAT_R_LOSS(ft)) << ft->Rshift) | \
-                ((g >> PG_FORMAT_G_LOSS(ft)) << ft->Gshift) | \
-                ((b >> PG_FORMAT_B_LOSS(ft)) << ft->Bshift) | \
-                ((a >> PG_FORMAT_A_LOSS(ft)) << ft->Ashift);  \
-            break;                                            \
-        case 4:                                               \
-            *((Uint32 *)(buf)) =                              \
-                ((r >> PG_FORMAT_R_LOSS(ft)) << ft->Rshift) | \
-                ((g >> PG_FORMAT_G_LOSS(ft)) << ft->Gshift) | \
-                ((b >> PG_FORMAT_B_LOSS(ft)) << ft->Bshift) | \
-                ((a >> PG_FORMAT_A_LOSS(ft)) << ft->Ashift);  \
-            break;                                            \
+#define CREATE_PIXEL(buf, r, g, b, a, bp, ft)                         \
+    switch (bp) {                                                     \
+        case 2:                                                       \
+            *((Uint16 *)(buf)) =                                      \
+                ((r >> PG_FORMAT_R_LOSS(ft)) << ft->Rshift) |         \
+                ((g >> PG_FORMAT_G_LOSS(ft)) << ft->Gshift) |         \
+                ((b >> PG_FORMAT_B_LOSS(ft)) << ft->Bshift) |         \
+                ((a >> PG_FORMAT_A_LOSS(ft)) << ft->Ashift);          \
+            break;                                                    \
+        case 4:                                                       \
+            *((Uint32 *)(buf)) =                                      \
+                ((Uint32)(r >> PG_FORMAT_R_LOSS(ft)) << ft->Rshift) | \
+                ((Uint32)(g >> PG_FORMAT_G_LOSS(ft)) << ft->Gshift) | \
+                ((Uint32)(b >> PG_FORMAT_B_LOSS(ft)) << ft->Bshift) | \
+                ((Uint32)(a >> PG_FORMAT_A_LOSS(ft)) << ft->Ashift);  \
+            break;                                                    \
     }
 
 /* Pretty good idea from Tom Duff :-). */

Original file line number	Diff line number	Diff line change
`@@ -1737,7 +1737,7 @@ _color_inv(pgColorObject *color)`
`1737`	`1737`	`static PyObject *`
`1738`	`1738`	`_color_int(pgColorObject *color)`
`1739`	`1739`	`{`
`1740`		`- Uint32 tmp = (color->data[0] << 24) + (color->data[1] << 16) +`
	`1740`	`+ Uint32 tmp = ((Uint32)color->data[0] << 24) + (color->data[1] << 16) +`
`1741`	`1741`	`(color->data[2] << 8) + color->data[3];`
`1742`	`1742`	`return PyLong_FromUnsignedLong(tmp);`
`1743`	`1743`	`}`
`@@ -1748,7 +1748,7 @@ _color_int(pgColorObject *color)`
`1748`	`1748`	`static PyObject *`
`1749`	`1749`	`_color_float(pgColorObject *color)`
`1750`	`1750`	`{`
`1751`		`- Uint32 tmp = ((color->data[0] << 24) + (color->data[1] << 16) +`
	`1751`	`+ Uint32 tmp = (((Uint32)color->data[0] << 24) + (color->data[1] << 16) +`
`1752`	`1752`	`(color->data[2] << 8) + color->data[3]);`
`1753`	`1753`	`return PyFloat_FromDouble((double)tmp);`
`1754`	`1754`	`}`
Original file line number	Diff line number	Diff line change
`@@ -734,7 +734,7 @@ array_to_surface(PyObject self, PyObject arg)`
`734`	`734`	`else {`
`735`	`735`	`Uint32 alpha = 0;`
`736`	`736`	`if (format->Amask) {`
`737`		`- alpha = 255 >> Aloss << Ashift;`
	`737`	`+ alpha = 255u >> Aloss << Ashift;`
`738`	`738`	`}`
`739`	`739`	`switch (view_p->itemsize) {`
`740`	`740`	`case sizeof(Uint8):`