From d399a6b23051335ce3107f11822ae352816fcd50 Mon Sep 17 00:00:00 2001 From: Simon Tatham Date: Sat, 11 Dec 2021 11:32:25 +0000 Subject: [PATCH] tree234: avoid an uninitialised-variable warning. Apparently, some compilers can't work out that the pattern if (!t->root) { special-case handler followed by early return } n = t->root; while (n) { ... } will execute the while loop at least once, on the grounds that the _first_ test for n being non-NULL must pass, because we initialised n from t->root which can't be NULL on any code path where we didn't take the early return. So they might give an uninitialised-variable warning for the variable 'ki', which is initialised inside the while loop. Compilers, eh. But it's easy enough to turn the while into a do-while, so that even the least alert compiler will know it runs at least once. --- tree234.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tree234.c b/tree234.c index 136f6e2..1cdae9f 100644 --- a/tree234.c +++ b/tree234.c @@ -332,7 +332,7 @@ static void *add234_internal(tree234 *t, void *e, int index) { } n = t->root; - while (n) { + do { LOG((" node %p: %p/%d \"%s\" %p/%d \"%s\" %p/%d \"%s\" %p/%d\n", n, n->kids[0], n->counts[0], n->elems[0], @@ -385,7 +385,7 @@ static void *add234_internal(tree234 *t, void *e, int index) { if (!n->kids[ki]) break; n = n->kids[ki]; - } + } while (n); add234_insert(NULL, e, NULL, &t->root, n, ki);