Re: [PULL v2 05/13] target/rx: CPU definitions

[Richard Henderson]

On 3/20/20 9:04 AM, Philippe Mathieu-Daudé wrote:
> Not related to this patch, but this line generates a warning with Clang:
> 
>   CC      rx-softmmu/target/rx/cpu.o
> target/rx/cpu.c:158:33: warning: The result of the left shift is undefined
> because the left operand is negative
>     address = physical = addr & TARGET_PAGE_MASK;
>                                 ^~~~~~~~~~~~~~~~
> include/exec/cpu-all.h:234:45: note: expanded from macro 'TARGET_PAGE_MASK'
> #define TARGET_PAGE_MASK   ((target_long)-1 << TARGET_PAGE_BITS)
>                             ~~~~~~~~~~~~~~~ ^
> 1 warning generated.

>From configure:

> # We use -fwrapv to tell the compiler that we require a C dialect where
> # left shift of signed integers is well defined and has the expected
> # 2s-complement style results. (Both clang and gcc agree that it
> # provides these semantics.)

Clang is *supposed* to be not generating those warnings.


r~