[Bug debug/86964] [7/8 Regression] Too many debug symbols included, especially for extern globals

[rguenther at suse dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86964

--- Comment #14 from rguenther at suse dot de <rguenther at suse dot de> ---
On Wed, 15 May 2019, patrickdepinguin at gmail dot com wrote:

> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86964
> 
> --- Comment #13 from Thomas De Schampheleire <patrickdepinguin at gmail dot com> ---
> I have applied the patch on a gcc 7.4 PPC toolchain, and tested on a code base
> where the problem existed. The original ELF object size (of one example source
> file) in a pre-gcc-7 toolchain (gcc 4.9.2) was 219K. With an unpatched gcc 7
> based toolchain, this had become 6.2M.
> 
> With the patch applied, with the same command-line as before, there is no
> change, i.e. object size is still 6.2M. Only by adding the extra option
> -feliminate-unused-debug-symbols, the object size drops back to a reasonable
> 218K.
> 
> My question is now: why is it needed to explicitly specify
> -feliminate-unused-debug-symbols? Is this an intended behavior change compared
> to e.g gcc 4.9?

We should probably switch the default to be consistent with
-feliminate-unused-debug-types