util: increase several macros limit from 255 to 4095

Currently, the following macros will only work for 0 - 255:
- `IS_EQ`
- `UTIL_X2`
- `UTIL_INC`
- `UTIL_DEC`
- `LISTIFY`

This patch increases their limit to 4095.

Signed-off-by: Yong Cong Sin <ycsin@meta.com>

include/zephyr/sys/util_macro.h

@@ -256,7 +256,7 @@ extern "C" {
  * @brief Like <tt>a == b</tt>, but does evaluation and
  * short-circuiting at C preprocessor time.
  *
- * This however only works for integer literal from 0 to 255.
+ * This however only works for integer literal from 0 to 4095.
  *
  */
 #define IS_EQ(a, b) Z_IS_EQ(a, b)
@@ -367,26 +367,26 @@ extern "C" {
 #define UTIL_AND(a, b) COND_CODE_1(UTIL_BOOL(a), (b), (0))
 
 /**
- * @brief UTIL_INC(x) for an integer literal x from 0 to 255 expands to an
+ * @brief UTIL_INC(x) for an integer literal x from 0 to 4095 expands to an
  * integer literal whose value is x+1.
  *
  * @see UTIL_DEC(x)
  */
-#define UTIL_INC(x) UTIL_PRIMITIVE_CAT(UTIL_INC_, x)
+#define UTIL_INC(x) UTIL_PRIMITIVE_CAT(Z_UTIL_INC_, x)
 
 /**
- * @brief UTIL_DEC(x) for an integer literal x from 0 to 255 expands to an
+ * @brief UTIL_DEC(x) for an integer literal x from 0 to 4095 expands to an
  * integer literal whose value is x-1.
  *
  * @see UTIL_INC(x)
  */
-#define UTIL_DEC(x) UTIL_PRIMITIVE_CAT(UTIL_DEC_, x)
+#define UTIL_DEC(x) UTIL_PRIMITIVE_CAT(Z_UTIL_DEC_, x)
 
 /**
- * @brief UTIL_X2(y) for an integer literal y from 0 to 255 expands to an
+ * @brief UTIL_X2(y) for an integer literal y from 0 to 4095 expands to an
  * integer literal whose value is 2y.
  */
-#define UTIL_X2(y) UTIL_PRIMITIVE_CAT(UTIL_X2_, y)
+#define UTIL_X2(y) UTIL_PRIMITIVE_CAT(Z_UTIL_X2_, y)
 
 
 /**
@@ -402,7 +402,7 @@ extern "C" {
  *    { MY_PWM0 , MY_PWM1 }
  *
  * @param LEN The length of the sequence. Must be an integer literal less
- *            than 255.
+ *            than 4095.
  * @param F A macro function that accepts at least two arguments:
  *          <tt>F(i, ...)</tt>. @p F is called repeatedly in the expansion.
  *          Its first argument @p i is the index in the sequence, and

scripts/utils/gen_util_macros.py

@@ -0,0 +1,163 @@
+"""
+Utility script to generate headers for the following macros
+- Z_LISTIFY
+- Z_UTIL_INC
+- Z_UTIL_DEC
+- Z_UTIL_X2
+- Z_IS_EQ
+
+.. note::
+    The script will simply create the header files in the current working directory,
+    they should be copied manually to $ZEPHYR_BASE/include/zephyr/sys/ accordingly.
+
+Usage::
+
+    python $ZEPHYR_BASE/scripts/utils/gen_util_macros.py -l 4095
+
+Copyright (c) 2023, Meta
+SPDX-License-Identifier: Apache-2.0
+"""
+
+import argparse
+
+def write_hidden_start(file):
+    file.write("/**\n")
+    file.write(" * @cond INTERNAL_HIDDEN\n")
+    file.write(" */\n")
+
+
+def write_hidden_stop(file):
+    file.write("/**\n")
+    file.write(" * INTERNAL_HIDDEN @endcond\n")
+    file.write(" */\n")
+
+
+def gen_util_listify(limit:int):
+    with open("util_listify.h", "w") as file:
+        write_hidden_start(file)
+        file.write("\n")
+        file.write("#ifndef ZEPHYR_INCLUDE_SYS_UTIL_LOOPS_H_\n")
+        file.write("#error \"This header should not be used directly, please include util_loops.h instead\"\n")
+        file.write("#endif /* ZEPHYR_INCLUDE_SYS_UTIL_LOOPS_H_ */\n")
+        file.write("\n")
+        file.write("#ifndef ZEPHYR_INCLUDE_SYS_UTIL_LISTIFY_H_\n")
+        file.write("#define ZEPHYR_INCLUDE_SYS_UTIL_LISTIFY_H_\n")
+        file.write("\n")
+
+        file.write("/* Set of UTIL_LISTIFY particles */\n")
+        file.write("#define Z_UTIL_LISTIFY_0(F, sep, ...)\n\n")
+        file.write("#define Z_UTIL_LISTIFY_1(F, sep, ...) \\\n")
+        file.write("	F(0, __VA_ARGS__)\n\n")
+
+        for i in range(2, limit + 3):
+            file.write(f"#define Z_UTIL_LISTIFY_{i}(F, sep, ...) \\\n")
+            file.write(f"	Z_UTIL_LISTIFY_{i - 1}(F, sep, __VA_ARGS__) __DEBRACKET sep \\\n")
+            file.write(f"	F({i - 1}, __VA_ARGS__)\n")
+
+        file.write("\n")
+        file.write("#endif /* ZEPHYR_INCLUDE_SYS_UTIL_LISTIFY_H_ */\n")
+        file.write("\n")
+        write_hidden_stop(file)
+
+
+def gen_util_internal_is_eq(limit):
+    with open("util_internal_is_eq.h", "w") as file:
+        write_hidden_start(file)
+        file.write("\n")
+        file.write("#ifndef ZEPHYR_INCLUDE_SYS_UTIL_INTERNAL_H_\n")
+        file.write("#error \"This header should not be used directly, \
+please include util_internal.h instead\"\n")
+        file.write("#endif /* ZEPHYR_INCLUDE_SYS_UTIL_INTERNAL_H_ */\n")
+        file.write("\n")
+        file.write("#ifndef ZEPHYR_INCLUDE_SYS_UTIL_INTERNAL_IS_EQ_H_\n")
+        file.write("#define ZEPHYR_INCLUDE_SYS_UTIL_INTERNAL_IS_EQ_H_\n")
+        file.write("\n")
+
+        for i in range(0, limit + 1):
+            file.write(f"#define Z_IS_{i}_EQ_{i}(...) \\,\n")
+
+        file.write("\n")
+        file.write("#endif /* ZEPHYR_INCLUDE_SYS_UTIL_INTERNAL_IS_EQ_H_ */\n")
+        file.write("\n")
+        write_hidden_stop(file)
+
+
+def gen_util_internal_util_inc(limit):
+    with open("util_internal_util_inc.h", "w") as file:
+        write_hidden_start(file)
+        file.write("\n")
+        file.write("#ifndef ZEPHYR_INCLUDE_SYS_UTIL_INTERNAL_H_\n")
+        file.write("#error \"This header should not be used directly, \
+please include util_internal.h instead\"\n")
+        file.write("#endif /* ZEPHYR_INCLUDE_SYS_UTIL_INTERNAL_H_ */\n")
+        file.write("\n")
+        file.write("#ifndef ZEPHYR_INCLUDE_SYS_UTIL_INTERNAL_UTIL_INC_H_\n")
+        file.write("#define ZEPHYR_INCLUDE_SYS_UTIL_INTERNAL_UTIL_INC_H_\n")
+        file.write("\n")
+
+        for i in range(0, limit + 2):
+            file.write(f"#define Z_UTIL_INC_{i} {i + 1}\n")
+
+        file.write("\n")
+        file.write("#endif /* ZEPHYR_INCLUDE_SYS_UTIL_INTERNAL_UTIL_INC_H_ */\n")
+        file.write("\n")
+        write_hidden_stop(file)
+
+
+def gen_util_internal_util_dec(limit):
+    with open("util_internal_util_dec.h", "w") as file:
+        write_hidden_start(file)
+        file.write("\n")
+        file.write("#ifndef ZEPHYR_INCLUDE_SYS_UTIL_INTERNAL_H_\n")
+        file.write("#error \"This header should not be used directly, \
+please include util_internal.h instead\"\n")
+        file.write("#endif /* ZEPHYR_INCLUDE_SYS_UTIL_INTERNAL_H_ */\n")
+        file.write("\n")
+        file.write("#ifndef ZEPHYR_INCLUDE_SYS_UTIL_INTERNAL_UTIL_DEC_H_\n")
+        file.write("#define ZEPHYR_INCLUDE_SYS_UTIL_INTERNAL_UTIL_DEC_H_\n")
+        file.write("\n")
+
+        file.write(f"#define Z_UTIL_DEC_0 0\n")
+        for i in range(1, limit + 2):
+            file.write(f"#define Z_UTIL_DEC_{i} {i - 1}\n")
+
+        file.write("\n")
+        file.write("#endif /* ZEPHYR_INCLUDE_SYS_UTIL_INTERNAL_UTIL_DEC_H_ */\n")
+        file.write("\n")
+        write_hidden_stop(file)
+
+
+def gen_util_internal_util_x2(limit):
+    with open("util_internal_util_x2.h", "w") as file:
+        write_hidden_start(file)
+        file.write("\n")
+        file.write("#ifndef ZEPHYR_INCLUDE_SYS_UTIL_INTERNAL_H_\n")
+        file.write("#error \"This header should not be used directly, \
+please include util_internal.h instead\"\n")
+        file.write("#endif /* ZEPHYR_INCLUDE_SYS_UTIL_INTERNAL_H_ */\n")
+        file.write("\n")
+        file.write("#ifndef ZEPHYR_INCLUDE_SYS_UTIL_INTERNAL_UTIL_X2_H_\n")
+        file.write("#define ZEPHYR_INCLUDE_SYS_UTIL_INTERNAL_UTIL_X2_H_\n")
+        file.write("\n")
+
+        for i in range(0, limit + 1):
+            file.write(f"#define Z_UTIL_X2_{i} {i *2}\n")
+
+        file.write("\n")
+        file.write("#endif /* ZEPHYR_INCLUDE_SYS_UTIL_INTERNAL_UTIL_X2_H_ */\n")
+        file.write("\n")
+        write_hidden_stop(file)
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(allow_abbrev=False)
+    parser.add_argument(
+        "-l", "--limit", type=int, required=True, help="Limit of macros"
+    )
+    args = parser.parse_args()
+
+    gen_util_listify(args.limit)
+    gen_util_internal_is_eq(args.limit)
+    gen_util_internal_util_inc(args.limit)
+    gen_util_internal_util_dec(args.limit)
+    gen_util_internal_util_x2(args.limit)