Re: build musl for armv7m

[Rich Felker <dalias@libc.org>]

On Wed, Jun 22, 2016 at 05:21:54PM -0700, Zhao, Weiming wrote:
> Fixed.
> 
> Btw, can we make exit() weak function? (patch attached)
> 
> This allows user code to redefine it because in baremetal
> environment, sometime we want to customize it. For example, some
> code never exits, so we can define a dummy exit() and thus save code
> size.

No, this is a hack and is not even needed to do what you're asking
for. The way linking an archive works, an object in the archive is
only pulled in to the link process when it satisfies an undefined
symbol reference, and if you defined your own exit, then exit.o would
never have reason to get linked.

But there are all sorts of things that can break unexpectedly from
redefining standard functions, which is why it's UB and this is not
supported usage.

Rich