posix: signal: implement addset

Implement POSIX signal API: sigaddset
Added ztest.

SIgned-off-by: Yong Cong Sin <[email protected]>

Author: ycsin

include/zephyr/posix/signal.h

@@ -102,6 +102,7 @@ typedef struct sigset {
 	uint32_t _elem[_SIGSET_NELEM];
 } sigset_t;
 
+int sigaddset(sigset_t *set, int signo);
 int sigemptyset(sigset_t *set);
 int sigfillset(sigset_t *set);
 #endif /* CONFIG_POSIX_SIGNAL */

lib/posix/signal/CMakeLists.txt

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: Apache-2.0
 
 zephyr_library_sources(
+  addset.c
   emptyset.c
   fillset.c
 )

lib/posix/signal/addset.c

@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2023 Meta
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <signal.h>
+#include <errno.h>
+
+int sigaddset(sigset_t *set, int signo)
+{
+	if ((set == NULL) || (signo <= 0) || (signo >= NSIG)) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	set->_elem[_SIGSET_NDX(signo)] |= _SIGNO2SET(signo);
+
+	return 0;
+}

tests/posix/signal/src/addset.c

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2023 Meta
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <signal.h>
+#include <errno.h>
+
+#include <zephyr/ztest.h>
+#include <zephyr/sys/util.h>
+#include <zephyr/sys/util_macro.h>
+
+ZTEST(posix_signal_apis, test_posix_signal_addset)
+{
+	sigset_t set;
+	int signo;
+	int rc;
+
+	for (int i = 0; i < ARRAY_SIZE(set._elem); i++) {
+		set._elem[i] = 0u;
+	}
+
+	signo = 21;
+	zassert_ok(sigaddset(&set, signo));
+	zassert_equal(set._elem[signo >> 5], BIT(signo), "Signal %d is not set", signo);
+
+	signo = 42;
+	zassert_ok(sigaddset(&set, signo));
+	zassert_equal(set._elem[21 >> 5], BIT(21), "Signal %d is not set", 21);
+	zassert_equal(set._elem[signo >> 5], BIT(signo % (8 * sizeof(set._elem[0]))),
+		      "Signal %d is not set", signo);
+
+	rc = sigaddset(&set, 0);
+	zassert_equal(rc, -1, "rc should be -1, not %d", rc);
+	zassert_equal(errno, EINVAL, "errno should be EINVAL, not %d", errno);
+
+	rc = sigaddset(&set, NSIG);
+	zassert_equal(rc, -1, "rc should be -1, not %d", rc);
+	zassert_equal(errno, EINVAL, "errno should be EINVAL, not %d", errno);
+}