Files
libakgl/tests/sprite.c
Andrew Kesterson 230278d303 Bound every array a data file can index
Closes Defects items 16 and 17 and Known-and-still-open item 6. All three let
an asset file, or a caller's argument, write past a fixed array.

akgl_sprite_load_json took its frame count straight from the document and wrote
that many entries into a 16-byte frameids -- through a uint32_t * cast of a
uint8_t *, so each write touched four bytes and the overrun reached four bytes
past the array, into the rest of akgl_Sprite and then the next pool slot. The
count is checked first now, each id is read into an int and narrowed
deliberately, and a frame number too large for a uint8_t is refused rather than
truncated into an index for a different tile.

The tilemap loader had the same shape twice: objects[j] with no check against
AKGL_TILEMAP_MAX_OBJECTS_PER_LAYER and tilesets[i] with none against
AKGL_TILEMAP_MAX_TILESETS. akgl_tilemap_load_layers already bounded its own
loop, so the pattern was in the same file. The object one is the reachable
half -- 128 objects is not a large object layer.

akgl_string_initialize zeroed sizeof(akgl_String) starting at `data`, which
begins after the refcount in front of it, so it ran four bytes past the end of
the object and onto the *next* slot's refcount -- the field the allocator reads
to decide whether a slot is free. Same file, same class, fixed with it:
akgl_string_copy accepted a count larger than the buffers, reading past one
pool slot and writing past another, which the header documented as behaviour.

Every case has a test that fails against the old code, with five new fixtures.
Exactly-the-maximum is asserted alongside one-past in each, so the bound cannot
be fixed by making the limit off by one.

25/25 pass, memcheck clean, reindent --check clean.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-01 07:33:37 -04:00

272 lines
10 KiB
C

#include <SDL3/SDL.h>
#include <SDL3_image/SDL_image.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <akerror.h>
#include <akgl/registry.h>
#include <akgl/sprite.h>
#include <akgl/heap.h>
#include <akgl/util.h>
#include <akgl/error.h>
#include <akgl/game.h>
#include <akgl/renderer.h>
#include "testutil.h"
akerr_ErrorContext *test_akgl_spritesheet_initialize(void)
{
PREPARE_ERROR(errctx);
akgl_SpriteSheet *sheet = NULL;
SDL_Texture *image = NULL;
akgl_String *tmpstr = NULL;
// Does the image file get loaded?
// Is the image file loaded correctly? (Surface comparison)
// Is the spritesheet in the registry?
ATTEMPT {
CATCH(errctx, akgl_heap_next_spritesheet(&sheet));
CATCH(errctx, akgl_heap_next_string(&tmpstr));
snprintf((char *)&tmpstr->data, AKGL_MAX_STRING_LENGTH, "%s%s", SDL_GetBasePath(), "assets/spritesheet.png");
CATCH(errctx, akgl_spritesheet_initialize(sheet, 48, 48, "assets/spritesheet.png"));
FAIL_ZERO_BREAK(errctx, sheet->texture, AKERR_VALUE, "akgl_spritesheet_initialize failed to load the sprite texture");
FAIL_NONZERO_BREAK(
errctx,
((sheet->texture->w != 576) || (sheet->texture->h != 384)),
AKERR_VALUE,
"Loaded texture was not the correct size");
snprintf((char *)&tmpstr->data, AKGL_MAX_STRING_LENGTH, "%s%s", SDL_GetBasePath(), "assets/spritesheet.png");
image = IMG_LoadTexture(akgl_renderer->sdl_renderer, (char *)&tmpstr->data);
FAIL_ZERO_BREAK(errctx, image, AKGL_ERR_SDL, "Failed to load comparison image");
CATCH(
errctx,
akgl_render_and_compare(
sheet->texture,
image,
0, 0, 576, 384,
"test_spritesheet_loaded_image.png")
);
FAIL_ZERO_BREAK(
errctx,
SDL_GetPointerProperty(AKGL_REGISTRY_SPRITESHEET, "assets/spritesheet.png", NULL),
AKERR_KEY,
"Spritesheet was not placed in the registry");
} CLEANUP {
IGNORE(akgl_heap_release_string(tmpstr));
IGNORE(akgl_heap_release_spritesheet(sheet));
if ( image != NULL )
SDL_DestroyTexture(image);
} PROCESS(errctx) {
} FINISH(errctx, true);
SUCCEED_RETURN(errctx);
}
akerr_ErrorContext *test_akgl_sprite_initialize(void)
{
PREPARE_ERROR(errctx);
akgl_SpriteSheet *testsheet = NULL;
akgl_Sprite *testsprite = NULL;
akgl_String *tmpstr = NULL;
// Does the sprite get loaded?
// Do all frames of the sprite get loaded?
// Are all the frames of the sprite what we expect? (Surface comparison)
// Is the sprite added to the registry?
ATTEMPT {
CATCH(errctx, akgl_heap_next_spritesheet(&testsheet));
CATCH(errctx, akgl_heap_next_sprite(&testsprite));
CATCH(errctx, akgl_heap_next_string(&tmpstr));
snprintf((char *)&tmpstr->data, AKGL_MAX_STRING_LENGTH, "%s%s", SDL_GetBasePath(), "assets/spritesheet.png");
CATCH(errctx, akgl_spritesheet_initialize(testsheet, 48, 48, "assets/spritesheet.png"));
FAIL_ZERO_BREAK(errctx, testsheet, AKERR_VALUE, "akgl_spritesheet_initialize failed");
CATCH(errctx, akgl_sprite_initialize(testsprite, "test", testsheet));
FAIL_NONZERO_BREAK(errctx, (testsprite->sheet != testsheet), AKERR_VALUE, "Initialized sprite uses wrong sheet");
FAIL_ZERO_BREAK(
errctx,
SDL_GetPointerProperty(AKGL_REGISTRY_SPRITE, "test", NULL),
AKERR_KEY,
"Sprite was not placed in the registry");
} CLEANUP {
IGNORE(akgl_heap_release_sprite(testsprite));
IGNORE(akgl_heap_release_string(tmpstr));
} PROCESS(errctx) {
} FINISH(errctx, true);
SUCCEED_RETURN(errctx);
}
akerr_ErrorContext *test_akgl_sprite_load_json(void)
{
PREPARE_ERROR(errctx);
akgl_Sprite *testsprite = NULL;
akgl_Sprite *testsprite2 = NULL;
akgl_String *tmpstr = NULL;
SDL_Texture *image = NULL;
// Does the sprite get loaded?
// Do all frames of the sprite get loaded?
// Are all the frames of the sprite what we expect? (Surface comparison)
// Is the sprite added to the registry?
ATTEMPT {
CATCH(errctx, akgl_heap_next_string(&tmpstr));
CATCH(errctx, akgl_sprite_load_json("assets/testsprite.json"));
testsprite = SDL_GetPointerProperty(AKGL_REGISTRY_SPRITE, "testsprite", NULL);
FAIL_ZERO_BREAK(
errctx,
testsprite,
AKERR_KEY,
"akgl_sprite_load_json succeeds but sprite is not placed in the registry");
FAIL_ZERO_BREAK(errctx, (testsprite->width == 48), AKERR_VALUE, "width incorrect (48 : %d)", testsprite->width);
FAIL_ZERO_BREAK(errctx, (testsprite->height == 48), AKERR_VALUE, "height incorrect (48 : %d)", testsprite->height);
FAIL_ZERO_BREAK(errctx, (testsprite->speed == 100000000), AKERR_VALUE, "speed incorrect (100 : %d)", testsprite->speed);
FAIL_ZERO_BREAK(errctx, (testsprite->loop == true), AKERR_VALUE, "loop incorrect (1 : %d)", testsprite->loop);
FAIL_ZERO_BREAK(errctx, (testsprite->loopReverse == true), AKERR_VALUE, "loopReverse incorrect (1 : %d)", testsprite->loopReverse);
FAIL_ZERO_BREAK(errctx, (testsprite->frames == 3), AKERR_VALUE, "frame count incorrect (3 : %d)", testsprite->frames);
FAIL_ZERO_BREAK(errctx, (testsprite->frameids[0] == 12), AKERR_VALUE, "frameids[0] incorrect (12 : %d)", testsprite->frameids[0]);
FAIL_ZERO_BREAK(errctx, (testsprite->frameids[1] == 13), AKERR_VALUE, "frameids[1] incorrect (13 : %d)", testsprite->frameids[1]);
FAIL_ZERO_BREAK(errctx, (testsprite->frameids[2] == 14), AKERR_VALUE, "frameids[2] incorrect (14 : %d)", testsprite->frameids[2]);
FAIL_NONZERO_BREAK(errctx, strcmp(testsprite->name, "testsprite"), AKERR_VALUE, "name incorrect (testsprite : %s)", (char *)testsprite->name);
// Is it using the right spritesheet?
snprintf((char *)&tmpstr->data, AKGL_MAX_STRING_LENGTH, "%s%s", SDL_GetBasePath(), "assets/spritesheet.png");
image = IMG_LoadTexture(akgl_renderer->sdl_renderer, (char *)&tmpstr->data);
FAIL_ZERO_BREAK(errctx, image, AKGL_ERR_SDL, "Failed to load comparison image");
CATCH(
errctx,
akgl_render_and_compare(
testsprite->sheet->texture,
image,
0, 0, 576, 384,
"test_sprite_loaded_from_json_sheet.png"
)
);
// If we load a second sprite using the same sheet name, do they use the same sheet in memory?
snprintf((char *)&tmpstr->data, AKGL_MAX_STRING_LENGTH, "%s%s", SDL_GetBasePath(), "assets/testsprite2.json");
CATCH(errctx, akgl_sprite_load_json("assets/testsprite2.json"));
testsprite2 = SDL_GetPointerProperty(AKGL_REGISTRY_SPRITE, "testsprite2", NULL);
FAIL_ZERO_BREAK(
errctx,
testsprite,
AKERR_KEY,
"akgl_sprite_load_json succeeds but second sprite is not placed in the registry");
FAIL_ZERO_BREAK(
errctx,
(testsprite->sheet == testsprite2->sheet),
AKERR_VALUE,
"Previously loaded spritesheets are not reused");
} CLEANUP {
if ( testsprite != NULL ) {
IGNORE(akgl_heap_release_sprite(testsprite));
}
if ( testsprite2 != NULL ) {
IGNORE(akgl_heap_release_sprite(testsprite2));
}
IGNORE(akgl_heap_release_string(tmpstr));
if ( image != NULL )
SDL_DestroyTexture(image);
} PROCESS(errctx) {
} FINISH(errctx, true);
SUCCEED_RETURN(errctx);
}
/**
* @brief A sprite definition must not be able to write past `frameids`.
*
* `frameids` is AKGL_SPRITE_MAX_FRAMES bytes and the loader took its count
* straight from the document, so a definition with seventeen frames wrote past
* the array, past the rest of akgl_Sprite, and into the next pool slot. It also
* wrote through a `uint32_t *` cast of a `uint8_t *`, four bytes at a time,
* which is why the overrun reached four bytes past the array rather than one.
*
* The neighbouring slot is claimed and stamped first, so the test fails on the
* corruption rather than on whatever the corruption happens to do later.
*/
akerr_ErrorContext *test_akgl_sprite_load_json_bounds_frames(void)
{
PREPARE_ERROR(errctx);
akgl_Sprite *loaded = NULL;
int i = 0;
ATTEMPT {
// Exactly the maximum is legal and must still load.
TEST_EXPECT_OK(errctx, akgl_sprite_load_json("assets/testsprite_maxframes.json"),
"loading a sprite with exactly AKGL_SPRITE_MAX_FRAMES frames");
loaded = SDL_GetPointerProperty(AKGL_REGISTRY_SPRITE, "testsprite_maxframes", NULL);
FAIL_ZERO_BREAK(errctx, loaded, AKERR_KEY, "the max-frames sprite is not in the registry");
TEST_ASSERT(errctx, loaded->frames == AKGL_SPRITE_MAX_FRAMES,
"max-frames sprite loaded %d frames, expected %d",
loaded->frames, AKGL_SPRITE_MAX_FRAMES);
for ( i = 0; i < AKGL_SPRITE_MAX_FRAMES; i++ ) {
TEST_ASSERT(errctx, loaded->frameids[i] == (uint8_t)i,
"max-frames sprite frame %d is %d, expected %d",
i, loaded->frameids[i], i);
}
// One more than the maximum is refused, and nothing is registered.
TEST_EXPECT_STATUS(errctx, AKERR_OUTOFBOUNDS,
akgl_sprite_load_json("assets/testsprite_toomanyframes.json"),
"loading a sprite with more frames than the array holds");
TEST_ASSERT(errctx,
SDL_GetPointerProperty(AKGL_REGISTRY_SPRITE, "testsprite_toomanyframes", NULL) == NULL,
"a sprite with too many frames was registered anyway");
// A frame number a uint8_t cannot hold is refused rather than truncated
// to something that indexes a different tile.
TEST_EXPECT_STATUS(errctx, AKERR_OUTOFBOUNDS,
akgl_sprite_load_json("assets/testsprite_widecount.json"),
"loading a sprite whose frame number does not fit a uint8_t");
} CLEANUP {
} PROCESS(errctx) {
} FINISH(errctx, true);
SUCCEED_RETURN(errctx);
}
int main(void)
{
PREPARE_ERROR(errctx);
ATTEMPT {
CATCH(errctx, akgl_error_init());
TEST_TRAP_UNHANDLED_ERRORS();
akgl_renderer = &akgl_default_renderer;
SDL_SetAppMetadata("SDL3-GameTest", "0.1", "net.aklabs.sdl3-gametest");
if (!SDL_Init(SDL_INIT_VIDEO | SDL_INIT_JOYSTICK | SDL_INIT_AUDIO )) {
FAIL_BREAK(errctx, AKGL_ERR_SDL, "Couldn't initialize SDL: %s", SDL_GetError());
}
if (!SDL_CreateWindowAndRenderer("net/aklabs/libakgl/test_sprite", 640, 480, 0, &akgl_window, &akgl_renderer->sdl_renderer)) {
FAIL_BREAK(errctx, AKGL_ERR_SDL, "Couldn't create window/renderer: %s", SDL_GetError());
}
akgl_renderer->draw_texture = &akgl_render_2d_draw_texture;
CATCH(errctx, akgl_heap_init());
CATCH(errctx, akgl_registry_init_sprite());
CATCH(errctx, akgl_registry_init_spritesheet());
CATCH(errctx, test_akgl_spritesheet_initialize());
CATCH(errctx, test_akgl_sprite_initialize());
CATCH(errctx, test_akgl_sprite_load_json());
CATCH(errctx, test_akgl_sprite_load_json_bounds_frames());
} CLEANUP {
} PROCESS(errctx) {
} FINISH_NORETURN(errctx);
return 0;
}