two small prep commits from the imds PR (#41316)

They are not directly IMDS stuff, and should be easy to merge ahead.

src/basic/cleanup-util.h

@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
+#include "assert-util.h"
 #include "cleanup-fundamental.h" /* IWYU pragma: export */
 
 typedef void (*free_func_t)(void *p);
@@ -89,3 +90,16 @@ typedef void* (*mfree_func_t)(void *p);
 #define DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(type, name, free_func)    \
         DEFINE_PUBLIC_TRIVIAL_REF_FUNC(type, name);                    \
         DEFINE_PUBLIC_TRIVIAL_UNREF_FUNC(type, name, free_func);
+
+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)

src/basic/macro.h

@@ -205,16 +205,3 @@ 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)

src/test/test-iovec-util.c

@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
 #include "iovec-util.h"
+#include "memory-util.h"
 #include "tests.h"
 
 TEST(iovec_memcmp) {
@@ -67,4 +68,11 @@ TEST(iovec_append) {
         assert_se(iovec_memcmp(&iov, &IOVEC_MAKE_STRING("waldoquuxp")) == 0);
 }
 
+TEST(iovec_make_byte) {
+        struct iovec x = IOVEC_MAKE_BYTE('x');
+
+        ASSERT_EQ(x.iov_len, 1U);
+        ASSERT_EQ(memcmp_nn(x.iov_base, x.iov_len, "x", 1), 0);
+}
+
 DEFINE_TEST_MAIN(LOG_INFO);