Enable debugging symbols to always use DWARF-4 format.
Adding -gdwarf-4 to make DWARF-4 the output format.
* gcc 4.6 outputs DWARF-2 by default
* gcc 4.7 outputs DWARF-4 by default
* clang <3.4 outputs DWARF-3 by default
* clang >3.4 outputs DWARF-4 by default
DWARF-4 is the latest debug output format which includes features for
macro-expansion, better var tracking and other similar options.
From http://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html
> -gdwarf-4
> Produce debugging information in DWARF format (if that is
> supported). The value of version may be either 2, 3 or 4; the
> default version for most targets is 4. Note that with DWARF
> Version 2, some ports require and always use some non-conflicting
> DWARF 3 extensions in the unwind tables.
>
> Version 4 may require GDB 7.0 and -fvar-tracking-assignments for
> maximum benefit.
BUG=
Review URL: https://codereview.chromium.org/198363002
Cr-Commit-Position: refs/heads/master@{#295933}
1 file changed
