[Dwarf-discuss] asmlinkage directive with debug_line ?

[Jun Koi]

Hi Micheal,


On 10/7/06, Michael Eager <eager at eagercon.com> wrote:
> Jun Koi wrote:
> > Hi,
> >
> > Anybody please tell me why asmlinkage directive in Linux kernel code
> > makes its content disappear from debug_line section?
> >
> > I compiled Linux kernel, and found that in a file with several
> > asmlinkage directives (like sys_read() in fs/read_write.c), many lines
> > are not listed in debug_line at all. Why that happened? And in that
> > case, how can a debugger solve the problem of reasoning to the source
> > code in a syscall?
>
> The DWARF mailing list is for discussions about the DWARF
> Debugging Standard, not about details of how a particular compiler
> or debugger implement the standard.
>
> Possibly someone on the GCC mailing list can offer
> some answer to your question.

I have found the reason: some lines that are missing from debug_line
are macro codes. There is nothing to do with the asmlinkage directive
at all.

>
> One first suggestion I would have is that you compile
> the source in question and take a look at the assembly
> code which the compiler generates.

Great idea, indeed. Thank you for this suggestion.


Best,
Jun