Re: [PATCH v2 8/8] linux-user: Simplify host <-> target errno conversion using macros

[Richard Henderson]

On 7/8/21 7:11 AM, Philippe Mathieu-Daudé wrote:
> Convert the host_to_target_errno_table[] array to a switch case
> to allow compiler optimizations. Extract the errnos list as to
> a new includible unit, using a generic macro. Remove the code
> related to target_to_host_errno_table[] initialization.
>
> Suggested-by: Richard Henderson <richard.henderson@linaro.org>
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>   linux-user/syscall.c    | 169 +++++-----------------------------------
>   linux-user/errnos.c.inc | 140 +++++++++++++++++++++++++++++++++
>   2 files changed, 161 insertions(+), 148 deletions(-)
>   create mode 100644 linux-user/errnos.c.inc
>
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 56682b06cbd..8bb528d2cf7 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -507,157 +507,37 @@ static inline int next_free_host_timer(void)
>   }
>   #endif
>   
> -#define ERRNO_TABLE_SIZE 1200
> -
>   static inline bool errno_exists(int err)
>   {
> -    return err >= 0 && err < ERRNO_TABLE_SIZE;
> +    switch (err) {
> +#define E(X)  case X: return true;
> +#include "errnos.c.inc"
> +#undef E
> +    default:
> +        return false;
> +    }
>   }

Not true.  As documented, errnos.c.inc only contains those errno values which are 
overridden, not all errno values which are valid.

r~