Re: [PATCH 27/74] lto: Mark EXPORT_SYMBOL symbols __visible

From: Rusty Russell
Date: Mon Aug 20 2012 - 03:01:39 EST


On Sat, 18 Aug 2012 19:56:23 -0700, Andi Kleen <andi@xxxxxxxxxxxxxx> wrote:
> @@ -78,11 +78,13 @@ extern struct module __this_module;
>
> #else /* !CONFIG_MODULES... */
>
> -#define EXPORT_SYMBOL(sym)
> -#define EXPORT_SYMBOL_GPL(sym)
> -#define EXPORT_SYMBOL_GPL_FUTURE(sym)
> -#define EXPORT_UNUSED_SYMBOL(sym)
> -#define EXPORT_UNUSED_SYMBOL_GPL(sym)
> +/* Even without modules keep the __visible side effect */
> +
> +#define EXPORT_SYMBOL(sym) extern typeof(sym) sym __visible
> +#define EXPORT_SYMBOL_GPL(sym) extern typeof(sym) sym __visible
> +#define EXPORT_SYMBOL_GPL_FUTURE(sym) extern typeof(sym) sym __visible
> +#define EXPORT_UNUSED_SYMBOL(sym) extern typeof(sym) sym __visible
> +#define EXPORT_UNUSED_SYMBOL_GPL(sym) extern typeof(sym) sym __visible
>
> #endif /* CONFIG_MODULES */

Really, why? Seems like a win to have them eliminated if unused.

Naively, I would think many cases of __visible should be #ifdef
CONFIG_MODULES. What am I missing?

Thanks,
Rusty.
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