code review 75230043: debug/macho: handle missing __debug_str section

debug/macho: handle missing __debug_str section

debug/elf does the same thing, use []byte{} for
any missing sections.

Fixes issue 7510

[khr, 2014-03-13 15:35:28]

Hello golang-codereviews@googlegroups.com,

I'd like you to review this change to
https://code.google.com/p/go/

[iant, 2014-03-13 16:12:56]

My reading of the code in debug/elf.File.DWARF is that any of the section is
permitted to be missing, not just the debug_str section.  Why not make this code
the same?

[khr, 2014-03-13 16:24:12]

On 2014/03/13 16:12:56, iant wrote:
> My reading of the code in debug/elf.File.DWARF is that any of the section is
> permitted to be missing, not just the debug_str section.  Why not make this
code
> the same?

We could.  debug/pe.File.DWARF feels the same way.  But someone explicitly added
this test at some point, I presume.  I'll check the history.

[khr, 2014-03-13 16:33:47]

On 2014/03/13 16:24:12, khr wrote:
> On 2014/03/13 16:12:56, iant wrote:
> > My reading of the code in debug/elf.File.DWARF is that any of the section is
> > permitted to be missing, not just the debug_str section.  Why not make this
> code
> > the same?
> 
> We could.  debug/pe.File.DWARF feels the same way.  But someone explicitly
added
> this test at some point, I presume.  I'll check the history.

Looks like it's been there since creation, in 2009.

https://code.google.com/p/go/source/detail?r=4cd799ff4deb

Russ, any idea why you made macho different than elf & pe?

[khr, 2014-03-13 16:35:34]

On 2014/03/13 16:33:47, khr wrote:
> On 2014/03/13 16:24:12, khr wrote:
> > On 2014/03/13 16:12:56, iant wrote:
> > > My reading of the code in debug/elf.File.DWARF is that any of the section
is
> > > permitted to be missing, not just the debug_str section.  Why not make
this
> > code
> > > the same?
> > 
> > We could.  debug/pe.File.DWARF feels the same way.  But someone explicitly
> added
> > this test at some point, I presume.  I'll check the history.
> 
> Looks like it's been there since creation, in 2009.
> 
> https://code.google.com/p/go/source/detail?r=4cd799ff4deb
> 
> Russ, any idea why you made macho different than elf & pe?

Ping to generate mail to Russ.

[rsc, 2014-03-13 17:20:42]

LGTM

No idea. If this works better, great. :-)

[khr, 2014-03-13 21:04:31]

*** Submitted as https://code.google.com/p/go/source/detail?r=08dcdcdb757b ***

debug/macho: handle missing __debug_str section

debug/elf does the same thing, use []byte{} for
any missing sections.

Fixes issue 7510

LGTM=rsc
R=golang-codereviews, iant
CC=golang-codereviews, rsc
https://codereview.appspot.com/75230043