3 files changed, 73 insertions, 0 deletions
diff --git a/ccan/ccan/array_size/LICENSE b/ccan/ccan/array_size/LICENSE
new file mode 120000
index 0000000..b7951da
--- /dev/null
+++ b/ccan/ccan/array_size/LICENSE
@@ -0,0 +1 @@
+../../licenses/CC0
+\ No newline at end of file
diff --git a/ccan/ccan/array_size/_info b/ccan/ccan/array_size/_info
new file mode 100644
index 0000000..69570f3
--- /dev/null
+++ b/ccan/ccan/array_size/_info
@@ -0,0 +1,46 @@
+#include "config.h"
+#include <stdio.h>
+#include <string.h>
+
+/**
+ * array_size - routine for safely deriving the size of a visible array.
+ *
+ * This provides a simple ARRAY_SIZE() macro, which (given a good compiler)
+ * will also break compile if you try to use it on a pointer.
+ *
+ * This can ensure your code is robust to changes, without needing a gratuitous
+ * macro or constant.
+ *
+ * Example:
+ *	// Outputs "Initialized 32 values\n"
+ *	#include <ccan/array_size/array_size.h>
+ *	#include <stdlib.h>
+ *	#include <stdio.h>
+ *
+ *	// We currently use 32 random values.
+ *	static unsigned int vals[32];
+ *
+ *	int main(void)
+ *	{
+ *		unsigned int i;
+ *		for (i = 0; i < ARRAY_SIZE(vals); i++)
+ *			vals[i] = random();
+ *		printf("Initialized %u values\n", i);
+ *		return 0;
+ *	}
+ *
+ * License: CC0 (Public domain)
+ * Author: Rusty Russell <rusty@rustcorp.com.au>
+ */
+int main(int argc, char *argv[])
+{
+	if (argc != 2)
+		return 1;
+
+	if (strcmp(argv[1], "depends") == 0) {
+		printf("ccan/build_assert\n");
+		return 0;
+	}
+
+	return 1;
+}
diff --git a/ccan/ccan/array_size/array_size.h b/ccan/ccan/array_size/array_size.h
new file mode 100644
index 0000000..0ca422a
--- /dev/null
+++ b/ccan/ccan/array_size/array_size.h
@@ -0,0 +1,26 @@
+/* CC0 (Public domain) - see LICENSE file for details */
+#ifndef CCAN_ARRAY_SIZE_H
+#define CCAN_ARRAY_SIZE_H
+#include "config.h"
+#include <ccan/build_assert/build_assert.h>
+
+/**
+ * ARRAY_SIZE - get the number of elements in a visible array
+ * @arr: the array whose size you want.
+ *
+ * This does not work on pointers, or arrays declared as [], or
+ * function parameters.  With correct compiler support, such usage
+ * will cause a build error (see build_assert).
+ */
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + _array_size_chk(arr))
+
+#if HAVE_BUILTIN_TYPES_COMPATIBLE_P && HAVE_TYPEOF
+/* Two gcc extensions.
+ * &a[0] degrades to a pointer: a different type from an array */
+#define _array_size_chk(arr)						\
+	BUILD_ASSERT_OR_ZERO(!__builtin_types_compatible_p(typeof(arr),	\
+							typeof(&(arr)[0])))
+#else
+#define _array_size_chk(arr) 0
+#endif
+#endif /* CCAN_ALIGNOF_H */