Re: [Elftoolchain-developers] a version of gcc 4.9.2 is generating DWARF source lines that elftoolchain does not parse but objdump will

[Kai W. <kai...@gm...>]

Daniel,

This should be fixed in r3164. Could you verify?

DWARF4 line section added a new field in the header and I missed that.
More work will probably be needed later but now the parsing part should be
ok.

/Kai

On Wed, Feb 18, 2015 at 7:31 AM, Daniel Wilkerson <
dan...@gm...> wrote:

> I tried using elftoolchain to parse the dwarf source line annotation
> output of vanilla gcc 4.9.2 and it works just fine.  In contrast, as
> stated below, parsing the output of the riscv-gcc 4.9.2 produces the
> error below: "Line info section too short".  Clearly this is a problem
> introduced by the riscv people.
>
> However, objdump parses the dwarf source line output of both compilers
> without complaint.  So if I report the bug to the riscv people at
> Berkeley that their compiler produces output that objdump likes but
> that elftoolchain will not parse, they can easily say that this is a
> bug in elftoolchain.
>
> I am basically blocked on this issue, so I am now in bug hell.  Any
> assistance would be greatly appreciated.  Can elftoolchain be made a
> bit more tolerant?  I will also write the riscv people.
>
> On Mon, Feb 16, 2015 at 1:07 PM, Daniel Wilkerson
> <dan...@gm...> wrote:
> > The RISC-V people at Berkeley have modified gcc 4.9.2 to target the
> > RISC-V ISA.  I have been able to use elftoolchain to parse the output
> > of previous versions of gcc which they have hacked, but not this one.
> > When I try to get the dwarf source lines from ELF they produce, as
> > follows:
> >
> > int const dwarf_src_res =
> >       dwarf_srclines(root_die, &lines, &num_lines, &dwarf_error);
> > . . .
> > fprintf(stderr, "Dwarf_Source_Lines:"
> >             "DW_DLE_NO_ENTRY:%d, DW_DLV_OK:%d, "
> >             "dwarf_src_res: %d\n",
> >             DW_DLE_NO_ENTRY, DW_DLV_OK, dwarf_src_res);
> > . . .
> > dwarf_errmsg(dwarf_error)
> >
> > I get a dwarf_src_res of 1:
> > Dwarf_Source_Lines:DW_DLE_NO_ENTRY:4, DW_DLV_OK:0, dwarf_src_res: 1
> >
> > And this error message:
> > Line info section too short [_dwarf_lineno_init(335)]
> >
> > However objdump reads and will output the source lines of the same ELF
> file.
> >
> > Is anyone else getting this result parsing the DWARF source lines
> > coming from, say, unmodified gcc 4.9.2 ?
> >
> > Daniel
>
>
> ------------------------------------------------------------------------------
> Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server
> from Actuate! Instantly Supercharge Your Business Reports and Dashboards
> with Interactivity, Sharing, Native Excel Exports, App Integration & more
> Get technology previously reserved for billion-dollar corporations, FREE
>
> http://pubads.g.doubleclick.net/gampad/clk?id=190641631&iu=/4140/ostg.clktrk
> _______________________________________________
> Elftoolchain-developers mailing list
> Elf...@li...
> https://lists.sourceforge.net/lists/listinfo/elftoolchain-developers
>