Hi Thomas,
On Sat, Jul 19, 2025 at 05:38:28PM +0200, Thomas Weißschuh wrote:
The toplevel Makefile is capable of calculating CC from CROSS_COMPILE and/or ARCH.
Stop passing the unnecessary variable.
(...)
# Execute the toplevel kernel Makefile -KBUILD_MAKE = $(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) +KBUILD_MAKE = $(MAKE) -C $(srctree) ARCH=$(ARCH) CROSS_COMPILE=$(CROSS_COMPILE)
Here the goal was not to help the toplevel Makefile figure CC, but rather to permit the user to override it, and it's also listed in "make help", and even used in cc-option.
I understnad that you're trying to avoid forcing CC to clang when building, but in this case, what will CROSS_COMPILE contain ? My guess is that you intend to make CROSS_COMPILE point to the gcc-based toolchain, and have CC point to clang for userland only. Is this the case ? I think I'd be fine with this, but then we need to make it explicit in the help message and fix the current one, possibly just with this:
- @echo " nolibc-test build the executable (uses $$CC and $$CROSS_COMPILE)" + @echo " nolibc-test build the executable (uses $$CC)" @echo " libc-test build an executable using the compiler's default libc instead" @echo " run-user runs the executable under QEMU (uses $$XARCH, $$TEST)" @echo " initramfs.cpio prepare the initramfs archive with nolibc-test" @echo " initramfs prepare the initramfs tree with nolibc-test" @echo " defconfig create a fresh new default config (uses $$XARCH)" - @echo " kernel (re)build the kernel (uses $$XARCH)" + @echo " kernel (re)build the kernel (uses $$XARCH, $$CROSS_COMPILE)"
Thanks, Willy