[PATCH v3 13/15] tests: Add wip_func utility

[Herve Codina <herve.codina@bootlin.com>]

wip_func is a test utility allowing to wrap the write inplace functions.

It allows to create tests with custom wip write sequence.

Also the modified dtb is saved allowing to perform later checks on this
modified dtb.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
 tests/Makefile.tests |   3 +-
 tests/meson.build    |   1 +
 tests/wip_func.c     | 127 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 130 insertions(+), 1 deletion(-)
 create mode 100644 tests/wip_func.c

diff --git a/tests/Makefile.tests b/tests/Makefile.tests
index 0d4d399f..a71c4cbf 100644
--- a/tests/Makefile.tests
+++ b/tests/Makefile.tests
@@ -31,7 +31,8 @@ LIB_TESTS_L = get_mem_rsv \
 	check_path check_header check_full \
 	fs_tree1 \
 	truncated_property truncated_string \
-	truncated_memrsv unterminated_memrsv
+	truncated_memrsv unterminated_memrsv \
+	wip_func
 LIB_TESTS = $(LIB_TESTS_L:%=$(TESTS_PREFIX)%)
 
 ifneq ($(STATIC_BUILD),1)
diff --git a/tests/meson.build b/tests/meson.build
index dae6a941..e7a88936 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -96,6 +96,7 @@ tests = [
   'truncated_string',
   'unterminated_memrsv',
   'utilfdt_test',
+  'wip_func',
 ]
 
 test_deps = [testutil_dep, util_dep, libfdt_dep]
diff --git a/tests/wip_func.c b/tests/wip_func.c
new file mode 100644
index 00000000..3becc4f1
--- /dev/null
+++ b/tests/wip_func.c
@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/*
+ * libfdt - Flat Device Tree manipulation
+ *	Wrapper wip functions family
+ * Copyright (C) 2026 Herve Codina, Bootlin.
+ */
+
+#include <inttypes.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <stdint.h>
+#include <errno.h>
+
+#include <libfdt.h>
+
+#include "tests.h"
+
+struct args {
+	char *dtb_path;
+	enum {
+		NOP_NODE,
+		NOP_PROP,
+		SET_PROP,
+	} op;
+	char *node_path;
+	char *prop_name;
+	int index;
+	char *value;
+};
+
+const char *usage_txt = "Usage:\n"
+	"  - wip_func <dtb> nop_node <node_path>\n"
+	"  - wip_func <dtb> nop_prop <node_path> <prop_name>\n"
+	"  - wip_func <dtb> set_prop <node_path> <prop_name> <index> <str>\n"
+	;
+
+static void parse_args(struct args *args, int argc, char *argv[])
+{
+	char *endptr;
+
+	memset(args, 0, sizeof(*args));
+
+	if (argc < 3)
+		goto fail;
+
+	args->dtb_path = argv[1];
+
+	if (!strcmp(argv[2], "nop_node")) {
+		args->op = NOP_NODE;
+		if (argc != 4)
+			goto fail;
+		args->node_path = argv[3];
+	} else if (!strcmp(argv[2], "nop_prop")) {
+		args->op = NOP_PROP;
+		if (argc != 5)
+			goto fail;
+		args->node_path = argv[3];
+		args->prop_name = argv[4];
+	} else if (!strcmp(argv[2], "set_prop")) {
+		args->op = SET_PROP;
+		if (argc != 7)
+			goto fail;
+		args->node_path = argv[3];
+		args->prop_name = argv[4];
+		errno = 0;
+		args->index = strtol(argv[5], &endptr, 0);
+		if (*endptr != '\0' || errno)
+			goto fail;
+		args->value = argv[6];
+	} else {
+		goto fail;
+	}
+
+	return;
+
+fail:
+	CONFIG("%s\n", usage_txt);
+}
+
+int main(int argc, char *argv[])
+{
+	struct args args;
+	void *fdt;
+	int node;
+	int err;
+
+	test_init(argc, argv);
+
+	parse_args(&args, argc, argv);
+
+	fdt = load_blob(args.dtb_path);
+
+	node = fdt_path_offset(fdt, args.node_path);
+	if (node < 0)
+		FAIL("Fail to get '%s': %s", args.node_path, fdt_strerror(node));
+
+	switch (args.op) {
+	case NOP_NODE:
+		err = fdt_nop_node(fdt, node);
+		if (err)
+			FAIL("fdt_nop_node('%s'): %s", args.node_path, fdt_strerror(err));
+		break;
+
+	case NOP_PROP:
+		err = fdt_nop_property(fdt, node, args.prop_name);
+		if (err)
+			FAIL("fdt_nop_node('%s', '%s'): %s", args.node_path,
+			     args.prop_name, fdt_strerror(err));
+		break;
+
+	case SET_PROP:
+		err = fdt_setprop_inplace_namelen_partial(fdt, node,
+			args.prop_name, strlen(args.prop_name), args.index,
+			args.value, strlen(args.value) + 1);
+		if (err)
+			FAIL("fdt_setprop_inplace_namelen_partial('%s', '%s', %d, \"%s\"): %s",
+			     args.node_path, args.prop_name, args.index,
+			     args.value, fdt_strerror(err));
+		break;
+	}
+
+	save_blob(args.dtb_path, fdt);
+
+	PASS();
+}
-- 
2.55.0