Re: [PATCH] final: Improve output for -dp and -fverbose-asm

[Michael Matz <matz@suse.de>]

Hi,

On Thu, 30 Nov 2017, David Malcolm wrote:

> -fverbose-asm is on the border of compiler-debugging vs end-user usage.

I have yet to see a relevant percentage of end-users who even know what 
assembler is.  On the gcc.*@ and kernel.* mailing lists, sure.  But Joe 
Randomapp?

> FWIW an improvement to -fverbose-asm was explicitly mentioned in the
> gcc 7 release notes:
>   https://gcc.gnu.org/gcc-7/changes.html
> and I've seen at least some end-users comment favorably on that change;
> this was:
>   https://gcc.gnu.org/ml/gcc-patches/2016-08/msg01051.html
> which was originally a "-fasm-show-source" option.

Yes.  I think this was actually a disservice to readability of 
-fverbose-asm (sorry!) and would have preferred a suboption as well (but 
wouldn't have complained if with-sources would be the default).  First, it 
clutters the asm instructions with intervening non-aligned lines (and 
left-hanging even, giving more visual importance to them instead of what 
is actually important, which for a switch named verbose-asm seems the asm 
to me) and second it has the same problem as debugging scheduled code: 
jumping around crazy and stating the same source line multiple times.  
(Basically the same reason 'objdump -dS' is similarly ugly, and why the -S 
therein is an extra switch).

Luckily -dp still works as expected, so, ... well, I guess I'll live, and 
if not there's "grep -v '^#.*:[0-9]\+:'" :)


Ciao,
Michael.