Am 23.12.2013 15:52, schrieb Michael S. Tsirkin:
> commit 5ce4f35781028ce1aee3341e6002f925fdc7aaf3
> "target-arm: A64: add set_pc cpu method"
>
> introduces an array aarch64_cpus which is zero
> size if this code is built without CONFIG_USER_ONLY.
> In particular an attempt to iterate over this array produces a warning
> under gcc 4.8.2:
>
> CC aarch64-softmmu/target-arm/cpu64.o
> /scm/qemu/target-arm/cpu64.c: In function ‘aarch64_cpu_register_types’:
> /scm/qemu/target-arm/cpu64.c:124:5: error: comparison of unsigned
> expression < 0 is always false [-Werror=type-limits]
> for (i = 0; i < ARRAY_SIZE(aarch64_cpus); i++) {
> ^
> cc1: all warnings being treated as errors
>
> This is the result of ARRAY_SIZE being an unsigned type,
> causing "i" to be promoted to unsigned int as well.
>
> As zero size arrays are a gcc extension, it seems
> cleanest to add a dummy element with NULL name,
> and test for it during registration.
>
> We'll be able to drop this when we add more CPUs.
>
> Cc: Alexander Graf <[email protected]>
> Cc: Peter Maydell <[email protected]>
> Cc: Richard Henderson <[email protected]>
> Signed-off-by: Michael S. Tsirkin <[email protected]>
> ---
> changes from v2:
> add more comments
> changes from v1:
> add a comment
>
> target-arm/cpu64.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/target-arm/cpu64.c b/target-arm/cpu64.c
> index 04ce879..60acd24 100644
> --- a/target-arm/cpu64.c
> +++ b/target-arm/cpu64.c
> @@ -58,6 +58,7 @@ static const ARMCPUInfo aarch64_cpus[] = {
> #ifdef CONFIG_USER_ONLY
> { .name = "any", .initfn = aarch64_any_initfn },
> #endif
> + { .name = NULL } /* TODO: drop when we support more CPUs */
> };
>
> static void aarch64_cpu_initfn(Object *obj)
> @@ -100,6 +101,11 @@ static void aarch64_cpu_register(const ARMCPUInfo *info)
> .class_init = info->class_init,
> };
>
> + /* TODO: drop when we support more CPUs - all entries will have name set
> */
> + if (!info->name) {
> + return;
> + }
> +
> type_info.name = g_strdup_printf("%s-" TYPE_ARM_CPU, info->name);
> type_register(&type_info);
> g_free((void *)type_info.name);
Reviewed-by: Stefan Weil <[email protected]>
