meson VS rr

[1]: https://github.com/mesonbuild/meson/issues/8153

The Meson build system Version: 1.2.3 Source dir: /home/patrik/workspace/Waybar Build dir: /home/patrik/workspace/Waybar/build Build type: native build Project name: waybar Project version: 0.9.24 C compiler for the host machine: cc (gcc 13.2.0 "cc (Debian 13.2.0-5) 13.2.0") C linker for the host machine: cc ld.bfd 2.41 C++ compiler for the host machine: c++ (gcc 13.2.0 "c++ (Debian 13.2.0-5) 13.2.0") C++ linker for the host machine: c++ ld.bfd 2.41 Host machine cpu family: x86_64 Host machine cpu: x86_64 Compiler for C++ supports link arguments -lc++fs: NO Compiler for C++ supports link arguments -lc++experimental: NO Compiler for C++ supports link arguments -lstdc++fs: YES Program git found: YES (/usr/bin/git) WARNING: You should add the boolean check kwarg to the run_command call. It currently defaults to false, but it will default to true in future releases of meson. See also: https://github.com/mesonbuild/meson/issues/9300 Has header "filesystem" : YES Checking if "nl_langinfo with _NL_TIME_WEEK_1STDAY, _NL_TIME_FIRST_WEEKDAY" : links: YES Run-time dependency threads found: YES Found pkg-config: /usr/bin/pkg-config (1.8.1) Run-time dependency fmt found: YES 9.1.0 Run-time dependency spdlog found: YES 1.12.0 Run-time dependency wayland-client found: YES 1.22.0 Run-time dependency wayland-cursor found: YES 1.22.0 Run-time dependency wayland-protocols found: YES 1.32 Run-time dependency gtkmm-3.0 found: YES 3.24.8 Run-time dependency dbusmenu-gtk3-0.4 found: YES 16.04.0 Run-time dependency gio-unix-2.0 found: YES 2.78.1 Run-time dependency jsoncpp found: YES 1.9.4 Run-time dependency sigc++-2.0 found: YES 2.12.1 Found CMake: /usr/bin/cmake (3.27.7) Run-time dependency libinotify found: NO (tried pkgconfig and cmake) Run-time dependency epoll-shim found: NO (tried pkgconfig and cmake) Run-time dependency libinput found: YES 1.23.0 Run-time dependency libnl-3.0 found: YES 3.7.0 Run-time dependency libnl-genl-3.0 found: YES 3.7.0 Run-time dependency upower-glib found: YES 1.90.2 Run-time dependency libpipewire-0.3 found: YES 0.3.85 Run-time dependency playerctl found: YES 2.4.1 Run-time dependency libpulse found: YES 16.1 Run-time dependency libudev found: YES 252 Run-time dependency libevdev found: YES 1.13.1 Run-time dependency libmpdclient found: YES 2.20 Run-time dependency xkbregistry found: YES 1.6.0 Run-time dependency jack found: YES 0.126.0 Run-time dependency wireplumber-0.4 found: YES 0.4.15 Library sndio found: YES Checking for function "sioctl_open" with dependency -lsndio: YES Run-time dependency gtk-layer-shell-0 found: YES 0.8.1 Run-time dependency systemd found: YES 252 Computing int of "__cpp_lib_chrono" : 201611 Configuring waybar.service using configuration Run-time dependency cava found: NO (tried pkgconfig and cmake) Looking for a fallback subproject for the dependency cava Executing subproject cava cava| Project name: cava cava| Project version: 0.9.1 cava| C compiler for the host machine: cc (gcc 13.2.0 "cc (Debian 13.2.0-5) 13.2.0") cava| C linker for the host machine: cc ld.bfd 2.41 cava| Has header "iniparser.h" : NO cava| Has header "iniparser4/iniparser.h" : NO Message: cava is not found. Building waybar without cava subprojects/cava-0.9.1/meson.build:65:3: ERROR: Problem encountered: iniparser library is required A full log can be found at /home/patrik/workspace/Waybar/build/meson-logs/meson-log.txt WARNING: Running the setup command as `meson [options]` instead of `meson setup [options]` is ambiguous and deprecated.

As it happens, I recently landed a PR in meson to add a clang-like Weverything mode that includes all of that, so you can get a minimal list of more or less all GCC warnings, organized by version, from the meson source here: https://github.com/mesonbuild/meson/blob/710a753c78077220b13a9f7e999dcdb61339efb1/mesonbuild/compilers/mixins/gnu.py

Came here to post the same. The answer for How to build software? is Meson[1] for C and C++ and also other languages. Works well on Windows and Mac, too.

I’ve written a small Makefile to learn the basic and backgrounds. Make is fine. But the next high-level would have been Autotools, which is an intimidating and weird set of tools. Most new stuff written in C/C++ use now Meson and it feels sane.

[1] https://mesonbuild.com

If you are very fortunate, you'll be able to choose something else. I like meson myself: it looks a bit like python, it's popular, small, simple, well-documented, easy to install and update, and it works well everywhere.

I suggest changing the build tool. Meson improved C and C++ a lot:

https://mesonbuild.com/

The dependency declaration and auto-detection is nice. But the hidden extra is WrapDB, built-in package management (if wanted):

    https://mesonbuild.com/Wrap-dependency-system-manual.html

> C's only REAL problem (in my opinion) which is the lack of dependency management. Most everything else can be done with a makefile and a half decent editor.

Care to hear about our lord and saviour Meson?

Both of your quoted problems are mutually incompatible: dependency management isn't the job of the compiler, it's a job for the build or host system. If you want to keep writing makefiles, be prepared to write your own `wget` and `git` invocations to download subprojects.

Meanwhile, Meson solves the dependency management problem in a way that makes both developers and system integrators/distributions happy. It forces you to make a project that doesn't have broken inter-file or header dependency chains and cleans up all the clutter and cruft of a makefile written for any non-trivial project, while making it trivial to integrate other meson projects into your build, let other people integrate your project into theirs, and provides all of the toggles and environment variables distribution developers need to package your library properly. You can really have your cake and eat it too.

https://mesonbuild.com/

Other people going down this route seem to end up writing cmake replacements instead. I'm thinking of something like meson here except that meson never intended to transpile to cmake.

I think this tool must share a lot techniques and use cases with rr. I wonder how it compares in various aspects.

https://rr-project.org/

rr "sells" as a "reversible debugger", but it obviously needs the determinism for its record and replay to work, and AFAIK it employs similar techniques regarding system call interception and serializing on a single CPU. The reversible debugger aspect is built on periodic snapshotting on top of it and replaying from those snapshots, AFAIK. They package it in a gdb compatible interface.

Hermit also lists record/replay as a motivation, although it doesn't list reversible debugging in general.

Interesting. Perhaps you can inspect the disassembly of the function in question when using Graal and HotSpot. It is likely related to that.

Another debugging technique we use for heisenbugs is to see if `rr` [1] can reproduce it. If it can then that's great as it allows you to go back in time to debug what may have caused the bug. But `rr` is often not great for concurrency bugs since it emulates a single-core machine. Though debugging a VM is generally a nightmare. What we desperately need is a debugger that can debug both the VM and the language running on top of it. Usually it's one or the other.

> In general I’d argue you haven’t fixed a bug unless you understand why it happened and why your fix worked, which makes this frustrating, since every indication is that the bug exists within proprietary code that is out of my reach.

Were you using Oracle GraalVM? GraalVM community edition is open source, so maybe it's worth checking if it is reproducible in that.

[1]: https://github.com/rr-debugger/rr

https://rr-project.org/ had the same problem. They use the retired conditional branch counter instead of instruction counter, and then instruction steeping until at the correct address.

That'll work great for your Distributed QSort Incorporated startup, where the only product is a sorting algorithm.

Formal software verification is very useful. But what can be usefully formalized is rather limited, and what can be formalized correctly in practice is even more limited. That means you need to restrict your scope to something sane and useful. As a result, in the real world running thousands of tests is practically useful. (Well, it depends on what those tests are; it's easy to write 1000s of tests that either test the same thing, or only test the things that will pass and not the things that would fail.) They are especially useful if running in a mode where the unexpected happens often, as it sounds like this system can do. (It's reminiscent of rr's chaos mode -- https://rr-project.org/ linking to https://robert.ocallahan.org/2016/02/introducing-rr-chaos-mo... )

The approach of check-pointing computation such that it is resumable and restartable sounds similar to a time-traveling debugger, like rr or WinDbg:

https://rr-project.org/

https://learn.microsoft.com/windows-hardware/drivers/debugge...

https://github.com/rr-debugger/rr?tab=readme-ov-file#system-...