Build Error with `clang20` Because Compiler flag `-c` Clashes with `-E`

[scratch-er]

Describe the bug

When building riscv64-nemu-interpreter with clang20, there are compiler errors because -c and -E is specified in the same command line in

NEMU/scripts/build.mk

Line 61 in 790edeb

@$(CC) $(CFLAGS) -E $(SO_CFLAGS) -c -o $@.c $<

To Reproduce

The toolchain used to build NEMU is clang20 from the package manager of Arch Linux.

Configure NEMU with defualt configs, except architecture is set to riscv64 and the compiler is set to clang. And then run make.

Expected behavior

The project should build currently.

Error log or Screenshots

clang: error: argument unused during compilation: '-c' [-Werror,-Wunused-command-line-argument]
make: *** [/home/scratcher/Workspace/NEMU/scripts/build.mk:61: /home/scratcher/Workspace/NEMU/build/obj-riscv64-nemu-interpreter/src/isa/riscv64/instr/decode.o] Error 1

Necessary information on versions

• NEMU version: master branch

[cebarobot]

Emmmm... Actually, the default config in menuconfig is not the real "default" config. This "default" config has never been tested, and is not promised to be good.

Please use the following command to setup the real default config:

make riscv64-xs_defconfig

Then, you can modify the compiler in menuconfig.

[scratch-er]

Emmmm... Actually, the default config in menuconfig is not the real "default" config. This "default" config has never been tested, and is not promised to be good.

Please use the following command to setup the real default config:

make riscv64-xs_defconfig

Then, you can modify the compiler in menuconfig.

Actually, ANY configs under the config/ directory are affected by this, as long as

• use clang20 as the compiler
• run make xxx_defconfig to select one config, for example, riscv64-xs-clang_defconfig
• run make menuconfig to set the compiler to clang if it is not
• run make

And the same error will be reproduced.