From: Lennart Poettering <lennart@poettering.net>
Date: Fri, 29 Aug 2025 21:19:35 +0000 (+0200)
Subject: macro: add simple DEFER_VOID_CALL() helper
X-Git-Tag: v259-rc1~451^2~4
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=71f3f1818f0e1cba565c6a7dde2ca1390a31ed6a;p=thirdparty%2Fsystemd.git

macro: add simple DEFER_VOID_CALL() helper
---

diff --git a/src/basic/macro.h b/src/basic/macro.h
index 3ddc5272b85..b53805d5b81 100644
--- a/src/basic/macro.h
+++ b/src/basic/macro.h
@@ -206,3 +206,16 @@ static inline size_t size_add(size_t x, size_t y) {
         for (typeof(entry) _va_sentinel_[1] = {}, _entries_[] = { __VA_ARGS__ __VA_OPT__(,) _va_sentinel_[0] }, *_current_ = _entries_; \
              ((long)(_current_ - _entries_) < (long)(ELEMENTSOF(_entries_) - 1)) && ({ entry = *_current_; true; }); \
              _current_++)
+
+typedef void (*void_func_t)(void);
+
+static inline void dispatch_void_func(void_func_t *f) {
+        assert(f);
+        assert(*f);
+        (*f)();
+}
+
+/* Inspired by Go's "defer" construct, but much more basic. This basically just calls a void function when
+ * the current scope is left. Doesn't do function parameters (i.e. no closures). */
+#define DEFER_VOID_CALL(x) _DEFER_VOID_CALL(UNIQ, x)
+#define _DEFER_VOID_CALL(uniq, x) _unused_ _cleanup_(dispatch_void_func) void_func_t UNIQ_T(defer, uniq) = (x)