[PATCH v2 0/4] Add capability to create property from old property

Allow construction of new values for a property using old property
value.

This was originally suggested in /append-property/ Patch series [0] and
can be used to achieve the same results (and much more).

In practice, it looks as follows:

dts-v1/;

/ {
	str-prop = "0";
	int-prop = <0>;
};

/ {
	str-prop = /./, "1", /./;
	int-prop = /./, <1>, /./;
};

dts to source output with -T -T also works as expected:

/dts-v1/;

/ { /* base.dts:3:3-5:3, base.dts:7:3-9:3 */
        int-prop = <0x00 0x01>, <0x02 0x03>, <0x00 0x01>; /* base.dts:4:9-4:26, base.dts:8:9-8:36 */
}; /* base.dts:3:3-5:3, base.dts:7:3-9:3 */

[0]: https://lore.kernel.org/devicetree-compiler/Z24nldCpXpoT7RaK@zatzit/T/#t

Signed-off-by: Ayush Singh <[email protected]>
---
Changes in v2:
- Compare against expected dtb instead of checking each property
  individually in tests.
- Use xstrdup when copying refs so each marker has it's own copy.
- Pass struct data by value, not by pointer.
- Add srcpos_free helper to properly free srcpos which have been
  extended previously.
- Remove open items since my original choices seem correct.
- Link to v1: https://lore.kernel.org/r/[email protected]

---
Ayush Singh (4):
      Add alloc_marker
      srcpos: Define srcpos_free
      dtc: Add /./
      tests: Add test for /./

 data.c                       | 20 +++++++++++++-----
 dtc-lexer.l                  |  5 +++++
 dtc-parser.y                 |  5 +++++
 dtc.h                        |  3 +++
 livetree.c                   | 50 ++++++++++++++++++++++++++++++++++++++++++--
 srcpos.c                     | 11 ++++++++++
 srcpos.h                     |  1 +
 tests/prev_prop.dts          | 25 ++++++++++++++++++++++
 tests/prev_prop_expected.dts | 13 ++++++++++++
 tests/run_tests.sh           |  5 +++++
 10 files changed, 131 insertions(+), 7 deletions(-)
---
base-commit: ce1d8588880aecd7af264e422a16a8b33617cef7
change-id: 20241227-previous-value-c22d4eeaae72

Best regards,
-- 
Ayush Singh <[email protected]>