make buildworld failed with error "relocation truncated to fit: R_ARM_JUMP24 against symbol `_fini'"

[Ian Lepore]

On Tue, 2016-01-19 at 11:46 -0800, Mark Millard wrote:
> On 2016-Jan-19, at 7:34 AM, Ian Lepore <ian at freebsd.org> wrote:
> > 
> > On Tue, 2016-01-19 at 11:58 +0000, Tom Vijlbrief wrote:
> > > Op ma 18 jan. 2016 20:37 schreef Mark Millard <
> > > markmi at dsl-only.net>:
> > > 
> > > > 
> > > > If you can tolerate tracking the 3.8.0 project (
> > > > base/projects/clang380-import ) until 3.8.0 is moved into 11.0
> > > > -CURRENT you
> > > > could find out that way if clang 3.8.0 behaves the same in your
> > > > context. So
> > > > far I've not come up with anything else
> > > 
> > > 
> > > I am having exactly the same buildworld problem on my RPI which
> > > used
> > > to
> > > build fine a week ago.
> > > 
> > > Currently testing the clang380-import branch as suggested to see
> > > if
> > > the
> > > problem persists.
> > 
> > The most confusing thing about this whole thread (besides the lack
> > of
> > logs so we're just guessing what's going on) is why this problem is
> > suddenly happening on clang 3.7.x (I guess it's 3.7.x here) when
> > that
> > has never been a problem before?  We needed to add the long-call
> > option
> > when testing clang 3.8, but why do we suddenly need it on clang 3.7
> > that hasn't needed it for months?
> > 
> > This very much has the feel of slapping a bandaid on something that
> > needs a better diagnosis (there may be internal bleeding).  If we
> > don't
> > understand why it's failing, it doesn't make sense to try to fix it
> > with the "cure" for a different problem.  (Maybe we never
> > understood
> > the clang 3.8 problem.)
> > 
> > -- Ian
> 
> The -mlong-calls were added to 11.0-CURRENT recently.
> 
> -r293648: 2016-Jan-10 (head/lib/csu/arm/Makefile)
> -r294031: 2016-Jan-14 (the rest added here)
> 
> May be a problem/incompleteness in the handling -mlong-calls itself?
> Are the above the right time frame for the problem starting for
> 3.7.1?

We've been using clang 3.7 since October.  We never needed -mlong-calls
until recently.  I had thought it was clang 3.8 that triggered the need
for -mlong-calls, but now we apparently have a report of clang 3.7.x
needing it.

So... why?  What changed, and why are we blindly reacting without
understanding?

-- Ian