When building foot with pgo under gentoo's portage, LLVM tried to
generate profile data files directly under system root, triggering
sandbox violation and causing build to fail. Setting this envvar fixes
the issue by explicitly specifying profiling data location.
Reference: https://clang.llvm.org/docs/UsersManual.html#profiling-with-instrumentation
On my system, GCC doesn't output its name when passing the --version
flag:
$ cc --version
cc (Debian 12.2.0-3) 12.2.0
Copyright (C) 2022 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
As the Free Software Foundation is unlikely to write another compiler, I
think that searching for the foundation's name instead of GCC is a good
enough fix (and I'm almost sure we wouldn't be the first ones to do so).
Appears to work, but cage spams a lot of
00:00:08.026 [types/wlr_output.c:720] Basic output test failed for HEADLESS-1
00:00:08.036 [types/wlr_output.c:720] Basic output test failed for HEADLESS-1
All scripts are in the ‘pgo’ directory:
* options: command line options for generate-alt-random-writes.py,
sourced by other scripts.
* pgo.sh: top-level script, generates a meson build directory, selects
a PGO method, generates the profiling data, re-configures the meson
build directory and does the final build.
This script is intended to be used by end-users, and shows _how_ to
integrate the script primitives.
Build servers will most likely *not* want to use this script as-is.
* partial.sh: generates alt-random-write data and runs “foot{,client}
--version”, and then feeds the alt-random data to the PGO helper
binary. Does not require a running Wayland session. Touches
$blddir/pgo-ok on success.
* full-inner.sh: runs “footclient --version”, and then a complex
“foot” command that first generates alt-random-write data, and then
“cat’s” it. Requires a running Wayland session, *but*, this script
is usually not called directly (see below). Touches $blddir/pgo-ok
onsucces..
* full-current-session.sh: runs full-inner.sh. That is, it runs foot
in the currently running Wayland session. Note that this will pop up a
foot window.
* full-headless-sway.sh: generates a custom Sway configuration that
exec’s foot-headless-sway-inner.sh (see below), and then executes a
headless Sway. In other words, this script does a *full* PGO build,
but *without* requiring a running Wayland session. Requires Sway >=
1.6.2.
* full-headless-sway.sh: runs full-inner.sh + “swaymsg exit”.
To do a custom PGO build, without using pgo.sh, you’d need to:
CFLAGS=”$CFLAGS -O3” meson --buildtype=release -Db_lto=true
meson configure -Db_pgo=generate
ninja
ninja test (only needed if tllist+fcft are built as subprojects)
Run *one* of:
- partial.sh
- full-current-session.sh
- full-headless-sway.sh
meson configure -D b_pgo=use
ninja
