From b389733ab0fa46f2cecd302cc5826fc7dc322c8e Mon Sep 17 00:00:00 2001 From: Randy Palamar Date: Sat, 6 Dec 2025 08:54:34 -0700 Subject: util: replace memrchr with internal version The amount of code we need to detect if this is present and handle the fallback is more than if we just provide it ourselves. Also we are passing in a difference of pointers so the argument type should be ptrdiff_t. This avoids a C brain damage of having unsigned size type which can wrap around if the caller is careful. --- text-iterator.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'text-iterator.c') diff --git a/text-iterator.c b/text-iterator.c index e080ca5..b61c609 100644 --- a/text-iterator.c +++ b/text-iterator.c @@ -1,6 +1,3 @@ -#ifndef _GNU_SOURCE -#define _GNU_SOURCE /* memrchr(3) is non-standard */ -#endif #include #include #include @@ -72,9 +69,19 @@ bool text_iterator_byte_prev(Iterator *it, char *b) { return true; } +static void *scan_memory_reverse(const void *memory, int byte, ptrdiff_t n) +{ + void *result = 0; + if (n > 0) { + const signed char *s = memory; + while (n) if (s[--n] == byte) { result = (void *)(s + n); break; } + } + return result; +} + bool text_iterator_byte_find_prev(Iterator *it, char b) { while (it->text) { - const char *match = memrchr(it->start, b, it->text - it->start); + const char *match = scan_memory_reverse(it->start, b, it->text - it->start); if (match) { it->pos -= it->text - match; it->text = match; -- cgit v1.2.3