systemd/0269-macro-introduce-FOREAC...

95 lines
2.9 KiB
Diff

From b9f50b820804113811bcf291f586793de434fcdc Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Sun, 5 Mar 2023 14:56:15 +0900
Subject: [PATCH] macro: introduce FOREACH_ARRAY() macro
The pattern that runs all array element is quite common.
But, sometimes, the number of element may be in a signed integer, or the
array may be NULL.
(cherry picked from commit 5716c27e1f52d2aba9dd02916c01d6271d9d0b16)
Related: #2182632
---
src/basic/macro.h | 7 ++++++
src/test/test-macro.c | 50 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 57 insertions(+)
diff --git a/src/basic/macro.h b/src/basic/macro.h
index 237117db12..b977730e54 100644
--- a/src/basic/macro.h
+++ b/src/basic/macro.h
@@ -329,6 +329,13 @@ static inline int __coverity_check_and_return__(int condition) {
#endif
#endif
+#define _FOREACH_ARRAY(i, array, num, m, s) \
+ for (typeof(num) m = (num); m > 0; m = 0) \
+ for (typeof(array[0]) *s = (array), *i = s; s && i < s + m; i++)
+
+#define FOREACH_ARRAY(i, array, num) \
+ _FOREACH_ARRAY(i, array, num, UNIQ_T(m, UNIQ), UNIQ_T(s, UNIQ))
+
#define DEFINE_TRIVIAL_DESTRUCTOR(name, type, func) \
static inline void name(type *p) { \
func(p); \
diff --git a/src/test/test-macro.c b/src/test/test-macro.c
index 049ea2c14e..6a5f4bbeb7 100644
--- a/src/test/test-macro.c
+++ b/src/test/test-macro.c
@@ -521,4 +521,54 @@ TEST(ISPOWEROF2) {
assert_se(!ISPOWEROF2(u));
}
+TEST(FOREACH_ARRAY) {
+ int a[10] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
+ int b[10] = { 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 };
+ int x, n;
+
+ x = n = 0;
+ FOREACH_ARRAY(i, a, 10) {
+ x += *i;
+ n++;
+ }
+ assert_se(x == 45);
+ assert_se(n == 10);
+
+ x = n = 0;
+ FOREACH_ARRAY(i, a, 10)
+ FOREACH_ARRAY(j, b, 10) {
+ x += (*i) * (*j);
+ n++;
+ }
+ assert_se(x == 45 * 45);
+ assert_se(n == 10 * 10);
+
+ x = n = 0;
+ FOREACH_ARRAY(i, a, 5)
+ FOREACH_ARRAY(j, b, 5) {
+ x += (*i) * (*j);
+ n++;
+ }
+ assert_se(x == 10 * 35);
+ assert_se(n == 5 * 5);
+
+ x = n = 0;
+ FOREACH_ARRAY(i, a, 0)
+ FOREACH_ARRAY(j, b, 0) {
+ x += (*i) * (*j);
+ n++;
+ }
+ assert_se(x == 0);
+ assert_se(n == 0);
+
+ x = n = 0;
+ FOREACH_ARRAY(i, a, -1)
+ FOREACH_ARRAY(j, b, -1) {
+ x += (*i) * (*j);
+ n++;
+ }
+ assert_se(x == 0);
+ assert_se(n == 0);
+}
+
DEFINE_TEST_MAIN(LOG_INFO);