[RFC] cygport: split debuginfo packages

[Jon TURNEY]

On 27/02/2015 06:27, Yaakov Selkowitz wrote:
> On Mon, 2015-02-23 at 12:14 +0000, Jon TURNEY wrote:
>> On 07/07/2012 14:10, Jon TURNEY wrote:
>>> I was going to suggest the use of objcopy --compress-debug-sections, but it
>>> appears that does nothing for PE/COFF files at the moment [1] :-(
>>>
>>> [1] http://sourceware.org/bugzilla/show_bug.cgi?id=14067
>>
>> That bug has been fixed for a while, so how about the attached?
>>
>> This appears to reduce the disk space used by .dbg files to about 1/3 of
>> the size, so seems worthwhile.
>
> Have you tested that the resulting split debuginfo work properly with
> gdb?

It's hardly a comprehensive test, but I did try this:

$ objdump -j ".zdebug_info" -s /usr/lib/debug/usr/bin/XWin.exe.dbg | head

/usr/lib/debug/usr/bin/XWin.exe.dbg:     file format pei-x86-64

Contents of section .zdebug_info:
  100635000 5a4c4942 00000000 0080a07f 789cecbd  ZLIB........x...
  100635010 797c9bd5 95377eef 23d97e64 f9b16547  y|...7~.#.~d..eG
  100635020 cb1363c7 929d10b3 24717687 24c4fb92  ..c.....$qv.$...
  100635030 788bed24 ceaac892 6c8bc896 90e4c406  x..$....l.......
  100635040 3a4d175a 2850680b 94524ae9 46693b33  :M.Z(Ph..RJ.Fi;3
  100635050 d0d26919 ba990205 0a2d740a 0cd36d68  ..i......-t...mh

$ gdb /usr/bin/XWin.exe
GNU gdb (GDB) 7.8
[...]
Reading symbols from /usr/bin/XWin.exe...Reading symbols from 
/usr/lib/debug//usr/bin/XWin.exe.dbg...done.
done.
(gdb) b main
Breakpoint 1 at 0x10057c147: file 
/usr/src/debug/xorg-server-1.17.1-2/hw/xwin/InitOutput.c, line 166.
(gdb) r
Starting program: /usr/bin/XWin.exe
[New Thread 2900.0x23e0]
[New Thread 2900.0xe8]

Breakpoint 1, main (argc=1, argv=0x23cb40, envp=0x6000281a0)
     at /usr/src/debug/xorg-server-1.17.1-2/hw/xwin/InitOutput.c:166
166     {