Re: [Tinycc-devel] Failed compilation on armel: bug?

[Daniel Glöckner]

Hi Thomas,

On Sun, May 08, 2011 at 11:21:49PM +0200, Thomas Preud'homme wrote:
> Le mardi 11 mai 2010 02:20:15, Daniel Glöckner a écrit :
> > On Mon, May 10, 2010 at 01:13:33AM +0200, Thomas Preud'homme wrote:
> > > tcc tests fails to run on armel debian build daemon and it doesn't seems
> > > like a debian specific issue as I got a "can't relocate at value x"
> > > message. See
> > > https://buildd.debian.org/fetch.cgi?pkg=tcc&arch=armel&ver=0.9.25-3&stam
> > > p=1273440303&file=log for more details.
> > 
> > There appear to be several issues with linking the debian libraries.
> > One of them is the lack of support for R_ARM_V4BX relocations in tinycc.
> > I'll probably have some more time to look deeper into this at the end of
> > the week.
> > 
> >   Daniel
> 
> Hi Daniel,
> 
> I looked into this problem again recently and realize the problem seems quite 
> obvious (or maybe not, in which case please correct me). The error happen 
> because there is a relative call whose offset cannot be encoded in 24 bits 
> (as 
> are relative call on arm). The symbol which fails to be relocated in dlopen 
> (or maybe dlsym, I already forgot). At first I thought: "How can dlopen be 
> relocated by tinycc and not by ld.so?" and then realized it's normal since 
> it's the ./tcc -run tcc.c -run tcc.c -run tcc.c test case. I guess in one of 
> the stage the glibc is mapped to far from the code and hence a relative call 
> can't be done.


> The thing here is that we are talking about relocation so we don't know the 
> address of the symbol at this stage. Maybe after relocation it will turn out 
> the symbol is too far and right now there is no fallback.

a fallback has been added by commit 741841d863be13.
Did you use the current mob branch for your tests?

  Daniel