life

commit c80091d4748c63f34b4320d8fcd395a85ab7fba2
parent ece9d3159b43d57b23b7415799dd7965b36421c3
Author: Michael Neuper <michael@michaelneuper.com>
Date:   Tue, 11 Nov 2025 08:41:52 +0200

remove goto's and fix memory leak

Diffstat:
M
life.c
 | 
73
++++++++++++++++++++++++++++++++++++++++---------------------------------

1 file changed, 40 insertions(+), 33 deletions(-)
diff --git a/life.c b/life.c
@@ -54,12 +54,12 @@ void  randomize_grid(Grid *grid);
 
 /* --- main routine --------------------------------------------------------- */
 
-int main(int argc, char *argv[]) {
+int main(void) {
     init_screen();
     game_loop();
     cleanup();
 
-    return 0;
+    return EXIT_SUCCESS;
 }
 
 /* -------------------------------------------------------------------------- */
@@ -72,7 +72,13 @@ void game_loop() {
     Grid  *cur    = init_grid(rows, cols);
     Grid  *next   = init_grid(rows, cols);
 
-    if (!(cur && next)) goto err;
+    if (!(cur && next)) {
+        cleanup();
+        if (cur) free_grid(cur);
+        if (next) free_grid(next);
+        fprintf(stderr, "Something terrible has happened.\n");
+        exit(1);
+    }
 
     struct timespec ts;
     ts.tv_sec  = 0;
@@ -107,14 +113,6 @@ void game_loop() {
 
     free_grid(cur);
     free_grid(next);
-    return;
-
-err:
-    cleanup();
-    if (cur) free_grid(cur);
-    if (next) free_grid(next);
-    fprintf(stderr, "Something terrible has happened.\n");
-    exit(1);
 }
 
 void tick(const Grid *cur, Grid *next) {
@@ -180,12 +178,26 @@ Grid *init_grid(size_t rows, size_t cols) {
     State **cells = malloc(rows * sizeof(State *));
     Grid   *grid  = malloc(sizeof(Grid));
 
-    if (!(grid && cells)) goto err;
+    if (!(grid && cells)) {
+        if (cells) free(cells);
+        if (grid) free(grid);
+
+        return NULL;
+    }
 
     for (size_t i = 0; i < rows; i++) {
         cells[i] = malloc(cols * sizeof(State));
-        if (!cells[i]) goto err; // FIXME memory leak
 
+        if (!cells[i]) {
+            for (size_t j = 0; j < i; j++)
+                free(cells[i]);
+            free(cells);
+            free(grid);
+
+            return NULL;
+        }
+
+        // initialize all cells to DEAD
         for (size_t j = 0; j < cols; j++) {
             cells[i][j] = DEAD;
         }
@@ -196,12 +208,6 @@ Grid *init_grid(size_t rows, size_t cols) {
     grid->cols  = cols;
 
     return grid;
-
-err:
-    if (cells) free(cells);
-    if (grid) free(grid);
-
-    return NULL;
 }
 
 void free_grid(Grid *grid) {
@@ -216,6 +222,7 @@ void free_grid(Grid *grid) {
 void print_grid(const Grid *grid) {
     for (size_t i = 0; i < grid->rows; i++) {
         for (size_t j = 0; j < grid->cols; j++) {
+            // print ' ' for dead cells to avoid having to clear the screen
             print_char(i, j, grid->cells[i][j] ? '#' : ' ', 0);
         }
     }
@@ -224,6 +231,8 @@ void print_grid(const Grid *grid) {
 }
 
 void set_grid(Grid *grid) {
+    bool paused = true;
+
     struct {
         size_t row, col;
     } curs = {grid->rows / 2, grid->cols / 2};
@@ -231,32 +240,32 @@ void set_grid(Grid *grid) {
     init_pair(CURS_COL, COLOR_BLUE, COLOR_BLACK);
     print_char(curs.row, curs.col, '*', CURS_COL);
 
-    while (true) {
+    while (paused) {
         int key = getch();
 
         switch (key) {
             case KEY_UP:
             case 'k':
             case 'w':
-                curs.row -= 1;
+                curs.row--;
                 break;
 
             case KEY_LEFT:
             case 'h':
             case 'a':
-                curs.col -= 1;
+                curs.col--;
                 break;
 
             case KEY_DOWN:
             case 'j':
             case 's':
-                curs.row += 1;
+                curs.row++;
                 break;
 
             case KEY_RIGHT:
             case 'l':
             case 'd':
-                curs.col += 1;
+                curs.col++;
                 break;
 
             case 't':
@@ -267,19 +276,22 @@ void set_grid(Grid *grid) {
                 randomize_grid(grid);
                 break;
 
+            case 'q':
+                free_grid(grid);
+                cleanup();
+                exit(0);
+
             case '\n':
             case '\r':
             case ' ':
             case 'e':
-                return;
-
-            case 'q':
-                goto quit;
+                paused = false;
 
             default:
                 continue;
         }
 
+        // wrap cursor around screen
         curs.row = (curs.row + grid->rows) % grid->rows;
         curs.col = (curs.col + grid->cols) % grid->cols;
 
@@ -287,11 +299,6 @@ void set_grid(Grid *grid) {
         print_grid(grid);
         print_char(curs.row, curs.col, '*', CURS_COL);
     }
-
-quit:
-    free_grid(grid);
-    cleanup();
-    exit(0);
 }
 
 void randomize_grid(Grid *grid) {