On 5/15/24 17:35, KP Singh wrote:
This helps in easily initializing blocks of code (e.g. static calls and
keys).
UNROLL(N, MACRO, __VA_ARGS__) calls MACRO N times with the first
argument as the index of the iteration. This allows string pasting to
create unique tokens for variable names, function calls etc.
As an example:
#include <linux/unroll.h>
#define MACRO(N, a, b) \
int add_##N(int a, int b) \
{ \
return a + b + N; \
}
UNROLL(2, MACRO, x, y)
expands to:
int add_0(int x, int y)
{
return x + y + 0;
}
int add_1(int x, int y)
{
return x + y + 1;
}
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
Acked-by: Song Liu <song@xxxxxxxxxx>
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Signed-off-by: KP Singh <kpsingh@xxxxxxxxxx>
looks good
Reviewed-by: John Johansen <john.johansen@xxxxxxxxxxxxx>
---
include/linux/unroll.h | 36 ++++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)
create mode 100644 include/linux/unroll.h
diff --git a/include/linux/unroll.h b/include/linux/unroll.h
new file mode 100644
index 000000000000..d42fd6366373
--- /dev/null
+++ b/include/linux/unroll.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Copyright (C) 2023 Google LLC.
+ */
+
+#ifndef __UNROLL_H
+#define __UNROLL_H
+
+#include <linux/args.h>
+
+#define UNROLL(N, MACRO, args...) CONCATENATE(__UNROLL_, N)(MACRO, args)
+
+#define __UNROLL_0(MACRO, args...)
+#define __UNROLL_1(MACRO, args...) __UNROLL_0(MACRO, args) MACRO(0, args)
+#define __UNROLL_2(MACRO, args...) __UNROLL_1(MACRO, args) MACRO(1, args)
+#define __UNROLL_3(MACRO, args...) __UNROLL_2(MACRO, args) MACRO(2, args)
+#define __UNROLL_4(MACRO, args...) __UNROLL_3(MACRO, args) MACRO(3, args)
+#define __UNROLL_5(MACRO, args...) __UNROLL_4(MACRO, args) MACRO(4, args)
+#define __UNROLL_6(MACRO, args...) __UNROLL_5(MACRO, args) MACRO(5, args)
+#define __UNROLL_7(MACRO, args...) __UNROLL_6(MACRO, args) MACRO(6, args)
+#define __UNROLL_8(MACRO, args...) __UNROLL_7(MACRO, args) MACRO(7, args)
+#define __UNROLL_9(MACRO, args...) __UNROLL_8(MACRO, args) MACRO(8, args)
+#define __UNROLL_10(MACRO, args...) __UNROLL_9(MACRO, args) MACRO(9, args)
+#define __UNROLL_11(MACRO, args...) __UNROLL_10(MACRO, args) MACRO(10, args)
+#define __UNROLL_12(MACRO, args...) __UNROLL_11(MACRO, args) MACRO(11, args)
+#define __UNROLL_13(MACRO, args...) __UNROLL_12(MACRO, args) MACRO(12, args)
+#define __UNROLL_14(MACRO, args...) __UNROLL_13(MACRO, args) MACRO(13, args)
+#define __UNROLL_15(MACRO, args...) __UNROLL_14(MACRO, args) MACRO(14, args)
+#define __UNROLL_16(MACRO, args...) __UNROLL_15(MACRO, args) MACRO(15, args)
+#define __UNROLL_17(MACRO, args...) __UNROLL_16(MACRO, args) MACRO(16, args)
+#define __UNROLL_18(MACRO, args...) __UNROLL_17(MACRO, args) MACRO(17, args)
+#define __UNROLL_19(MACRO, args...) __UNROLL_18(MACRO, args) MACRO(18, args)
+#define __UNROLL_20(MACRO, args...) __UNROLL_19(MACRO, args) MACRO(19, args)
+
+#endif /* __UNROLL_H */
