Add memory allocation checks

Closes #18.

src/engine.c

@@ -216,10 +216,10 @@ static int digits_ceiling(unsigned int n)
 struct gamestate* gamestate_init(int argc, char **argv)
 {
     struct gameoptions *opt = gameoptions_default();
-    if (argc != 0) parse_options(opt, argc, argv);
-
     if (!opt) return NULL;
 
+    if (argc != 0) parse_options(opt, argc, argv);
+
     srand(time(NULL));
 
     struct gamestate *g = malloc(sizeof(struct gamestate));

src/engine.h

@@ -2,6 +2,7 @@
 #define ENGINE_H
 
 #include <stdio.h>
+#include <stdlib.h>
 #include "options.h"
 
 #define fatal(msg)\

src/gfx_curses.c

@@ -26,6 +26,8 @@ struct gfx_state* gfx_init(struct gamestate *g)
     refresh();
 
     struct gfx_state *s = malloc(sizeof(struct gfx_state));
+    if (!s) return NULL;
+
     s->window_height = g->opts->grid_height * (g->print_width + 2) + 3;
     s->window_width  = g->opts->grid_width * (g->print_width + 2) + 1;
     s->window = newwin(s->window_height, s->window_width, 1, 1);

src/main.c

@@ -14,10 +14,18 @@ void draw_then_sleep(struct gfx_state *s, struct gamestate *g)
 int main(int argc, char **argv)
 {
     struct gamestate *g = gamestate_init(argc, argv);
+    if (!g) {
+        fatal("failed to allocate gamestate");
+    }
+
     struct gfx_state *s = NULL;
 
-    if (g->opts->interactive)
+    if (g->opts->interactive) {
         s = gfx_init(g);
+        if (!s) {
+            fatal("failed to allocate gfx state");
+        }
+    }
 
     int game_running = true;
     while (game_running) {