[PATCH] D13365: [ELF2] Fix mixed-Endian handling in DynamicSection<ELFT>::writeTo

[Hal Finkel via llvm-commits]

----- Original Message -----
> From: "Hal Finkel" <hfinkel at anl.gov>
> To: "Rafael Espíndola" <rafael.espindola at gmail.com>
> Cc: "Rui Ueyama" <ruiu at google.com>, "llvm-commits" <llvm-commits at lists.llvm.org>, "Adhemerval Zanella"
> <adhemerval.zanella at linaro.org>, reviews+D13365+public+c4deb05b041f4664 at reviews.llvm.org
> Sent: Friday, October 2, 2015 10:12:25 AM
> Subject: Re: [PATCH] D13365: [ELF2] Fix mixed-Endian handling in DynamicSection<ELFT>::writeTo
> 
> ----- Original Message -----
> > From: "Rafael Espíndola" <rafael.espindola at gmail.com>
> > To: reviews+D13365+public+c4deb05b041f4664 at reviews.llvm.org
> > Cc: "Hal Finkel" <hfinkel at anl.gov>, "Rui Ueyama" <ruiu at google.com>,
> > "llvm-commits" <llvm-commits at lists.llvm.org>,
> > "Adhemerval Zanella" <adhemerval.zanella at linaro.org>
> > Sent: Friday, October 2, 2015 8:48:03 AM
> > Subject: Re: [PATCH] D13365: [ELF2] Fix mixed-Endian handling in
> > DynamicSection<ELFT>::writeTo
> > 
> > It should be possible to add a testcase with a big ending .o file
> > that
> > is currently failing when running on a little endian machine, no?
> > LGTM wit that.
> 
> Actually, I think I can just make the existing test cases run for
> targets of both Endian choices. Then one or the other would fail
> depending on the host byte ordering.
> 

r249150, thanks!

 -Hal

> Thanks again,
> Hal
> 
> > 
> > On 1 October 2015 at 16:27, hfinkel at anl.gov <hfinkel at anl.gov>
> > wrote:
> > > hfinkel created this revision.
> > > hfinkel added reviewers: ruiu, rafael.
> > > hfinkel added a subscriber: llvm-commits.
> > > hfinkel added a project: lld.
> > >
> > > Using the "raw" Elf64_Dyn or Elf32_Dyn structures in
> > > DynamicSection<ELFT>::writeTo does not correctly handle
> > > mixed-Endian situations. Instead, use the corresponding
> > > llvm::object::* structures which have Endian-converting members
> > > (like the rest of the code).
> > >
> > > This fixes all currently-failing elf2 tests when running on
> > > big-Endian PPC64/Linux.
> > >
> > >
> > > http://reviews.llvm.org/D13365
> > >
> > > Files:
> > >   ELF/OutputSections.cpp
> > >   ELF/OutputSections.h
> > >
> > > Index: ELF/OutputSections.h
> > > ===================================================================
> > > --- ELF/OutputSections.h
> > > +++ ELF/OutputSections.h
> > > @@ -316,6 +316,7 @@
> > >    typedef typename llvm::object::ELFFile<ELFT>::Elf_Rel Elf_Rel;
> > >    typedef typename llvm::object::ELFFile<ELFT>::Elf_Rela
> > >    Elf_Rela;
> > >    typedef typename llvm::object::ELFFile<ELFT>::Elf_Sym Elf_Sym;
> > > +  typedef typename llvm::object::ELFFile<ELFT>::Elf_Dyn Elf_Dyn;
> > >
> > >  public:
> > >    DynamicSection(SymbolTable &SymTab, HashTableSection<ELFT>
> > >    &HashSec,
> > > Index: ELF/OutputSections.cpp
> > > ===================================================================
> > > --- ELF/OutputSections.cpp
> > > +++ ELF/OutputSections.cpp
> > > @@ -216,8 +216,6 @@
> > >  }
> > >
> > >  template <class ELFT> void DynamicSection<ELFT>::writeTo(uint8_t
> > >  *Buf) {
> > > -  typedef typename std::conditional<ELFT::Is64Bits, Elf64_Dyn,
> > > Elf32_Dyn>::type
> > > -      Elf_Dyn;
> > >    auto *P = reinterpret_cast<Elf_Dyn *>(Buf);
> > >
> > >    if (RelaDynSec.hasRelocs()) {
> > >
> > >
> > 
> 
> --
> Hal Finkel
> Assistant Computational Scientist
> Leadership Computing Facility
> Argonne National Laboratory
> 

-- 
Hal Finkel
Assistant Computational Scientist
Leadership Computing Facility
Argonne National Laboratory