https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115211
Bug ID: 115211
Summary: [11/12/13/14/15 regression] -frecord-gcc-switches
refactoring lost list of enabled options
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: other
Assignee: unassigned at gcc dot gnu.org
Reporter: ro at gcc dot gnu.org
Target Milestone: ---
When investigating PR libstdc++/111641, I had the need to determine if
-funwind-tables is enabled by default on various targets. Previously, this
could be done as easily as assembling an empty file with -dA -fverbose-asm
and looking for the "options enabled" comment in there (or, as I recently
learned, by just adding -Q -v to the compile command).
To my dismay, I found that this facility has been removed since GCC 11 by
this commit:
commit 7caa49706316e650fb67719e1a1bf3a35054b685
Author: Martin Liska <mli...@suse.cz>
Date: Mon Nov 23 13:40:04 2020 +0100
Refactor -frecord-gcc-switches.
-[fg]record-gcc-switches is no replacement since it only includes the options
explicitly passed on the command line, not the enabled ones. I know of no
replacement at all for this facitlity, and digging through the mazes of option
handling in toplev.cc, opts.cc, target option handling code is a totally losing
proposition.
Martin argued in
https://gcc.gnu.org/pipermail/gcc-patches/2020-November/560358.html
that the support in GCC 10 were incomplete, but any support is better than
nothing at all. Going back to GCC 10 may sort of work for a while, but over
time the divergence will become so great that the result is useless.
