RFC: [PATCH] Make -static builds work again without crashing
vda.linux at googlemail.com
Mon Apr 14 17:47:05 UTC 2008
On Monday 14 April 2008 19:11, Maarten Lankhorst wrote:
> > > After some experimenting I came to the conclusion that the minimum app
> > > that won't crash with gcc -static is printf("%.0d", 0); which is
> > > essentially a noop printf. So my patch calls that before calling main.
> > >
> > > Looking for feedback on the patch.
> > ?!
> > Ths will force stdio to be linked it into every application.
> > How about fixing the problem instead of papering over it?
> > I think the possible reason is that _stdio_init is a weak symbol:
> > extern void weak_function _stdio_init(void) attribute_hidden;
> > and here we check that it was linked in, only if it was, we run it:
> > /*
> > * Initialize stdio here. In the static library case, this will
> > * be bypassed if not needed because of the weak alias above.
> > * Thus we get a nice size savings because the stdio functions
> > * won't be pulled into the final static binary unless used.
> > */
> > if (likely(_stdio_init != NULL))
> > _stdio_init();
> > But current gcc assumes (and it's allowed by C standard) that function
> > address is never NULL. So it optimizes away this if(), and calls
> > _stdio_init() unconditionally. If it indeed is NULL, we crash.
> I don't think this is the issue here, if I remove the call to
> _stdio_init call in __uClibc_init it will still crash.
Just adding bogus printf is still not a solution.
Where it crashes?
More information about the uClibc