Re: [PATCH] x86, acpi: LLVMLinux: Remove nested functions from Thinkpad ACPI

From: Måns Rullgård
Date: Wed Feb 12 2014 - 16:35:03 EST


Behan Webster <behanw@xxxxxxxxxxxxxxxxxx> writes:

> On 02/12/14 13:11, Christoph Hellwig wrote:
>> On Wed, Feb 12, 2014 at 09:58:46PM +0100, dl9pf@xxxxxx wrote:
>>> being able to compile the Linux kernel with Clang. The use of nested functions
>>> blocks this effort.
>> Is there any good way to make gcc warn about the use of nested functions?
> Interesting idea.
>
> '-Wtrampolines'
> Warn about trampolines generated for pointers to nested functions.
>
> A trampoline is a small piece of data or code that is created at
> run time on the stack when the address of a nested function is
> taken, and is used to call the nested function indirectly. For
> some targets, it is made up of data only and thus requires no
> special treatment. But, for most targets, it is made up of code
> and thus requires the stack to be made executable in order for the
> program to work properly.
>
> That might work.

That sounds like it will only warn if a trampoline is needed. A nested
function whose address isn't taken, as is the case here, wouldn't
trigger this warning.

--
Måns Rullgård
mans@xxxxxxxxx
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