llvm dev - Dec 2006 - [LLVMdev] [patch] [llvm-gcc4] fix bootstrap failure

On 11/30/06, Andrew Lenharth <andrewl at lenharth.org>
wrote:
> The llvm_ostreams, which you take the address of go out of scope very
> quickly, and are only stored by address in the bytecode writer, thus
> the writers have a pointer to a stack allocated object they are to
> write to.  This crashes.
The attached version leaks :-)
It is a work around. If I understand correctly, the ostream wrapper is
also a temporary solution, so this might be acceptable.
> Andrew
Thanks,
Rafael
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On 11/30/06, Rafael Espíndola <rafael.espindola at gmail.com>
wrote:
> On 11/30/06, Andrew Lenharth <andrewl at lenharth.org> wrote:
> > The llvm_ostreams, which you take the address of go out of scope very
> > quickly, and are only stored by address in the bytecode writer, thus
> > the writers have a pointer to a stack allocated object they are to
> > write to.  This crashes.
>
> The attached version leaks :-)
> It is a work around. If I understand correctly, the ostream wrapper is
> also a temporary solution, so this might be acceptable.
Hmm, that looks like what I did in my tree :)

Andrew

On 11/30/06, Rafael Espíndola <rafael.espindola at gmail.com>
wrote:
> On 11/30/06, Andrew Lenharth <andrewl at lenharth.org> wrote:
> > The llvm_ostreams, which you take the address of go out of scope very
> > quickly, and are only stored by address in the bytecode writer, thus
> > the writers have a pointer to a stack allocated object they are to
> > write to.  This crashes.
>
> The attached version leaks :-)
> It is a work around. If I understand correctly, the ostream wrapper is
> also a temporary solution, so this might be acceptable.
>
Hey guys,

Notice that the llvm_ostream doesn't delete the ostream that you pass
into it. If you want to make sure that it's deleted, I think you'll
want to pass in "true" to the WriteBytecodePass so that it'll
delete
the llvm_ostream. This won't affect the AsmOutFile, which gets deleted
at the end of the function...

-bw

Actually, take a look at the current TOT for llvm-gcc4. Jim & I put a
patch in there yesterday that should make things work with
llvm_ostreams.

-bw

On 11/30/06, Bill Wendling <isanbard at gmail.com>
wrote:
> On 11/30/06, Rafael Espíndola <rafael.espindola at gmail.com> wrote:
> > On 11/30/06, Andrew Lenharth <andrewl at lenharth.org> wrote:
> > > The llvm_ostreams, which you take the address of go out of scope
very
> > > quickly, and are only stored by address in the bytecode writer,
thus
> > > the writers have a pointer to a stack allocated object they are
to
> > > write to.  This crashes.
> >
> > The attached version leaks :-)
> > It is a work around. If I understand correctly, the ostream wrapper is
> > also a temporary solution, so this might be acceptable.
> >
>
> Hey guys,
>
> Notice that the llvm_ostream doesn't delete the ostream that you pass
> into it. If you want to make sure that it's deleted, I think you'll
> want to pass in "true" to the WriteBytecodePass so that it'll
delete
> the llvm_ostream. This won't affect the AsmOutFile, which gets deleted
> at the end of the function...
>
> -bw
>