Add -Wall,-Werror compiler flags

src/builtins.c

@@ -31,6 +31,9 @@ LISP_FUNC_1(ucl_builtin_type, scope, arg) {
             assert(0);
             return NULL;
     }
+
+    assert(0);
+    return ucl_error_create("Unreachable error in 'ucl_builtin_type'");
 }
 
 LISP_FUNC_1(ucl_builtin_error, scope, arg) {
@@ -147,7 +150,7 @@ LISP_FUNC_2(ucl_builtin_concat, scope, arg0, arg1) {
     }
 
     int len = strlen(arg0->string) + strlen(arg1->string);
-    char *outstr = malloc(strlen(arg0->string) + strlen(arg1->string));
+    char *outstr = malloc(len);
     outstr[0] = '\0';
     strcat(outstr, arg0->string);
     strcat(outstr, arg1->string);

src/evaluate.c

@@ -91,4 +91,7 @@ struct ucl_object *ucl_evaluate(struct ucl_scope *scope, struct ucl_object *obj)
             assert(0);
             return NULL;
     }
+
+    assert(0);
+    return ucl_error_create("Unreachable error in ucl_evaluate");
 }

src/memory.c

@@ -115,6 +115,7 @@ void ucl_object_delete(struct ucl_object *obj) {
             break;
         case UCL_TYPE_INT:
         case UCL_TYPE_BUILTIN:
+        case UCL_TYPE_SPECIAL:
         case UCL_TYPE_COUNT:
             break;
     }

src/utility.c

@@ -144,6 +144,9 @@ void ucl_print_obj(struct ucl_object *obj) {
         case UCL_TYPE_BUILTIN:
             printf("<builtin %p>", obj->builtin);
             break;
+        case UCL_TYPE_SPECIAL:
+            printf("<special %p>", obj->special);
+            break;
         case UCL_TYPE_CELL: {
             int first = true;
             printf("%s", "(");
@@ -212,4 +215,6 @@ struct ucl_object *ucl_equal(
             return ucl_error_create("");
     }
 
+    assert(0);
+    return ucl_error_create("Unreachable error in ucl_equal");
 }