On Tue, 4 Apr 2023, Nathan Chancellor wrote: > When building with clang's integrated assembler, it points out that the > CONFIG_CPU_HAS_DIEI versions of local_irq_enable and local_irq_disable > have a named parameter that is not used in the body of the macro and it > thinks that $8 is a positional parameter, rather than a register: > > arch/mips/include/asm/asmmacro.h:48:2: warning: macro defined with named > parameters which are not used in macro body, possible positional parameter found > in body which will have no effect > .macro local_irq_enable reg=$8 > ^ > > The comment above the function that performs this check in LLVM notes > that the warning may trigger in this case, even though it is not > problematic. It is easy enough to clean this up by just omitting the > named parameter for this version of the macro, as it is entirely unused. You need to remove the argument from the !CONFIG_CPU_HAS_DIEI versions of the macros then too or otherwise we now have an inconsistent API between kernel configurations. AFAICT the only call site is in arch/mips/kernel/entry.S (and for `local_irq_enable' only), and it doesn't supply the argument, which is why you could have removed it for CONFIG_CPU_HAS_DIEI at all. FWIW I find your reported warning questionable, there are valid reasons, such as the very situation here, why an argument might not be used. It is only a macro after all, effectively a source code transformation tool. Similarly the C preprocessor does not warn about unused macro arguments. So IMHO your change has crippled reasonable code just to paper over a tool's deficiency. Maciej
