[Interest] Qt 5 LTO build on OS X 10.9 (and earlier)
René J. V. Bertin
rjvbertin at gmail.com
Sat Sep 12 00:19:27 CEST 2015
Thiago Macieira wrote:
> I have no clue what issues with debugging there might be. I haven't
> experienced that problem with GCC's LTO.
It's like debugging an application or library built without -g. Indeed, I
haven't noticed any issue like that with gcc 5 on Linux.
>> Well, yes, it's something to do with the linker, but the end result is that
>> symbolic or source-level (or whatever you wish to call it) is possible or
>> not ...
> I don't see any reason why the compiler would get lost.
And I have no idea why you drag the compiler into this :)
My hunch is that the -g is dropped during the linking stage, it doesn't show in
the ld arguments at least. The way I think of it is that LTO basically repeats
part of the compilation or maybe just the assembly-level optimisation after
loading all code that must be linked together. If that's done after dropping -g,
that would explain the absence of debug information in the resulting binary.
(then again that might be as close to the truth as Genesis is :) )
More information about the Interest