[PATCH v6 0/4] RISC-V: re-enable gcc + rust builds

[Asuna Yang]

Previous v5 patch:
https://lore.kernel.org/20251204-gcc-rust-v5-v5-0-2d4f20d86c24@gmail.com

Changes in v6:
- Simplified `bindgen-backend-option` Kconfig function by using
`/dev/null` with clang option `-x c` instead of `touch`ing a new temp
file.
- Moved the `BINDGEN_TARGET` check to `rust/Makefile` so it only
performs the check when Rust is enabled, avoiding breaking targets that
do not support Rust builds.
- Updated my git email to the institutional email address.

Signed-off-by: Asuna Yang <xinrui.riscv at isrc.iscas.ac.cn>
---
Asuna Yang (4):
      rust: export BINDGEN_TARGET from a separate Makefile
      rust: generate a fatal error if BINDGEN_TARGET is undefined
      rust: add a Kconfig function to test for support of bindgen options
      RISC-V: handle extension configs for bindgen, re-enable gcc + rust builds

 Documentation/rust/arch-support.rst |  2 +-
 Makefile                            |  3 ++-
 arch/riscv/Kconfig                  | 35 ++++++++++++++++++++++++++++++++++-
 rust/Makefile                       | 17 ++++++++---------
 scripts/Kconfig.include             |  5 +++++
 scripts/Makefile.rust               | 10 ++++++++++
 6 files changed, 60 insertions(+), 12 deletions(-)
---
base-commit: 8640b74557fc8b4c300030f6ccb8cd078f665ec8
change-id: 20251204-gcc-rust-v5-aafcede31ea3

Best regards,
-- 
Asuna Yang <xinrui.riscv at isrc.iscas.ac.cn>