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To clarify what this means, since things can get confusing with subtle differences in wordings: * stage1 is when zig is built from C++ code[1] (the "bootstrap"

To clarify what this means, since things can get confusing with subtle differences in wordings: * stage1 is when zig is built from C++ code[1] (the "bootstrap" compiler) using system C/C++ compiler toolchain. * stage2 is when zig is built from Zig code[2] using stage1. * stage3 is when zig is rebuilt from the same Zig code[2] using stage2. Before today, zig would give you stage1 by default, and you could opt in to stage2 using `-fno-stage1`. After today, zig gives you stage3 by default, and you can opt in to stage1 using `-fstage1`. In all three cases, LLVM is being used. Although Zig has started to fully self-host by providing backends that have no dependency on LLVM, none of these fully self-hosted backends are complete. Why bother self-hosting? Because: * Zig produces smaller, faster binaries than C++ that use less memory[4]. Case in point: the new self-hosted compiler is 1.5x faster than the C++ implementation and uses 3x less peak RAM. * Development velocity in Zig is much faster than C++, and debugging is a breeze in comparison due to Zig being much safer than C++ and having better debug tooling. Similarly, comptime features let us add more assertions and debug checks that are not possible in C++. * Zig compiles much faster than C++. * Zig cross compiles better than C++ making it easier to create builds of the compiler for every target. * The self-hosted compiler does not need a softfloat library dependency to support f16 or f128 operations. * Zig's std lib data structures are incredibly useful, especially compared to the C++ STL. There are still many known bugs; not every project will be able to upgrade immediately. See the full upgrade guide [3] for help deciding when and how to upgrade. [1]: https://github.com/ziglang/zig/tree/master/src/stage1 https://github.com/ziglang/zig/tree/master/src/stage1 [2]: https://github.com/ziglang/zig/tree/master/src https://github.com/ziglang/zig/tree/master/src [3]: https://github.com/ziglang/zig/wiki/Self-Hosted-Compiler-Upgrade-Guide/ https://github.com/ziglang/zig/wiki/Self-Hosted-Compiler-Upg... [4]: https://media.handmade-seattle.com/practical-data-oriented-design/ https://media.handmade-seattle.com/practical-data-oriented-d...

kuon 4y ago
Congratulations. This is an important milestone.
- childintime 4y ago
  For Andrew it must feel he's now on the home stretch towards 1.0, finally!
  - ksec 4y ago
    In a previous presentation I think he mentions they are still aiming at something like 2025.
lewurm 4y ago
Thanks for the context! What's the difference between the stage2 and stage3 binary? Does stage1 produce different binaries for the same input compared to stage2/stage3?
- amaranth 4y ago
  Ideally there should be no difference and building stage 3 is basically a sanity check to ensure the compiler is working correctly.
  - AndyKelley 4y ago
    Not quite - what you said is true for a hypothetical "stage4" however there is a distinct difference between stage2 and stage3. While they are built from the same source code, and therefore have the same logic, they are lowered by different backends, meaning they will have potentially drastically different performance characteristics depending on the differences between the stage1 and stage2 backend, respectively. Related: https://github.com/ziglang/zig/issues/12183 https://github.com/ziglang/zig/issues/12183
llimllib 4y ago
> having better debug tooling What debug tooling are you referring to? It seems like people just use lldb to debug zig programs? I'm honestly interested, and searching doesn't turn up good tools as far as I can tell.
- cturtle 4y ago
  Maybe the runtime safety in debug builds? Like for out of bounds, int overflows, etc. In my zig projects those checks have saved me from using a debugger or valgrind in many cases.
  - llimllib 4y ago
    I guess I don't call runtime safety features "debug tooling"? But maybe that's the disconnect here
    - klyrs 4y ago
      I'd call tools like ASAN and friends debug tooling. I'm not sure if zig has tooling that doesn't have an analogue in the c++ world, but having them built in to the compiler by default is a notable feature.
      - tialaramex 4y ago
        Right, defaults matter. The fact sanitizers exist is much less of a game changer than the default behaviour being sanitized. Because C++ defaults are notoriously all wrong, in programming language design you could usually do worse than consider, "Is there an alternative to what C++ does here by default?" and if there is one, choose that alternative as your default because it's more likely to be correct. Sometimes C++ helps you out, it might have a keyword "do_it_right" and you can just default to that, if you feel people might want the C++ default behaviour, feel free to reserve "do_it_wrong" in case people wanted that, but in many cases they will never ask you to implement the C++ behaviour because it's just wrong. Examples: "const" in C++ doesn't mean "constant" it means "immutable", so, make immutable your default and offer "mutable" as the option. "explicit" in C++ makes constructors need an explicit cast to be used for conversion, once again of course you want that by default but feel free to reserve "implicit" in case some people are sure they need the C++ behaviour.
conaclos 4y ago
> Case in point: the new self-hosted compiler is 1.5x faster than the C++ implementation and uses 3x less peak RAM. I am not sure it is comparable: the self-hosted compiler uses a different architecture [1]. [1] https://vimeo.com/649009599/7f1fda43ff https://vimeo.com/649009599/7f1fda43ff
- Laremere 4y ago
  This is true, but I don't think your point entirely fair either. Zig's design lends itself to writing this style of code. In contrast the usual way(s) C++ is used encourages code that makes these types of optimizations hard/impossible. In practical terms, if you wanted to write fast software, the ergonomics of the language allowing you to use the desired architecture matter a lot. (Also, you're replying to the primary author of Zig and presenter of that talk, if you weren't aware.)
  - kaba0 4y ago
    While ergonomics matter, I don’t believe the question is settled at all - for very high performance applications C++ is the answer for a long time to come.
chris2860 4y ago
Hi Andrew, sorry for the unrelated question but where can we find the financial reports of the Zig Software Foundation for 2022? The Finances spreadsheet hasn't been updated for the past half a year: https://docs.google.com/spreadsheets/d/14_ljFHGFXY5NhBhlfjgkO0RZHqeVv04fAmCxw3ZusYc/edit#gid=99104331 https://docs.google.com/spreadsheets/d/14_ljFHGFXY5NhBhlfjgk...
- killingtime74 4y ago
  Isn’t it quite common to only do financial reports only every quarter, 6 months, yearly?
dilap 4y ago
> * Zig's std lib data structures are incredibly useful, especially compared to the C++ STL. I think elaborating on this could make for a very interesting article. :-) (I have a guess already at one item, which is MultiArrayList, something that kind of blew my mind when I first learned about it, and is in my opinion a very impressive testament to both the power and ease of use of Zig's approach to compile-time computation.)
- sekao 4y ago
  I didn't even know about it until today, very impressive. Generic SoA in less than 500 lines of userland code... https://github.com/ziglang/zig/blob/master/lib/std/multi_array_list.zig https://github.com/ziglang/zig/blob/master/lib/std/multi_arr...
  - jcelerier 4y ago
    SoA in C++ isn't that long, here's my version (which for sure does not have the utility functions defined here though, but is useful enough for me): https://github.com/celtera/ahsohtoa/blob/main/include/ahsohtoa/ahsohtoa.hpp https://github.com/celtera/ahsohtoa/blob/main/include/ahsoht...
    - dilap 4y ago
      That's pretty sweet, I didn't know C++ could do this now! Zig's still got it beat handily in simplicity though -- I think what's really cool about Zig's idea of comp-time evaluation is you get something like the power of C++ with something like the simplicity of C.
labrador 4y ago
> Zig produces smaller, faster binaries than C++ This seems fairly significant to me and makes me wonder how this is possible with all the effort that has gone into optimizing C++
- kristoff_it 4y ago
  right after that sentence there's a link to a talk that explains one way this is true
  - labrador 4y ago
    We can hardly be expected to watch a 46 minute video on "A Practical Guide to Applying Data-Oriented Design" to find our answer. It seems unpromising on the surface.
    - JonChesterfield 4y ago
      Data oriented design is why the thing is faster.
      - labrador 4y ago
        I guess I'll wait for the benchmarks comparing C++ and Zig over a variety of problem solutions to see which one is faster
- rk06 4y ago
  Because they can't do breaking changes and must live with legacy baggage. While zig can work use modern techniques without such issues
  - labrador 4y ago
    This is wrong because you can strip out C++ code you don't need. Green code doesn't need to worry about legacy baggage

kuon 4y ago

Congratulations. This is an important milestone.

childintime 4y ago
For Andrew it must feel he's now on the home stretch towards 1.0, finally!
- ksec 4y ago
  In a previous presentation I think he mentions they are still aiming at something like 2025.

lewurm 4y ago

Thanks for the context! What's the difference between the stage2 and stage3 binary? Does stage1 produce different binaries for the same input compared to stage2/stage3?

amaranth 4y ago
Ideally there should be no difference and building stage 3 is basically a sanity check to ensure the compiler is working correctly.
- AndyKelley 4y ago
  Not quite - what you said is true for a hypothetical "stage4" however there is a distinct difference between stage2 and stage3. While they are built from the same source code, and therefore have the same logic, they are lowered by different backends, meaning they will have potentially drastically different performance characteristics depending on the differences between the stage1 and stage2 backend, respectively. Related: https://github.com/ziglang/zig/issues/12183 https://github.com/ziglang/zig/issues/12183

llimllib 4y ago

> having better debug tooling What debug tooling are you referring to? It seems like people just use lldb to debug zig programs? I'm honestly interested, and searching doesn't turn up good tools as far as I can tell.

cturtle 4y ago
Maybe the runtime safety in debug builds? Like for out of bounds, int overflows, etc. In my zig projects those checks have saved me from using a debugger or valgrind in many cases.
- llimllib 4y ago
  I guess I don't call runtime safety features "debug tooling"? But maybe that's the disconnect here
  - klyrs 4y ago
    I'd call tools like ASAN and friends debug tooling. I'm not sure if zig has tooling that doesn't have an analogue in the c++ world, but having them built in to the compiler by default is a notable feature.
    - tialaramex 4y ago
      Right, defaults matter. The fact sanitizers exist is much less of a game changer than the default behaviour being sanitized. Because C++ defaults are notoriously all wrong, in programming language design you could usually do worse than consider, "Is there an alternative to what C++ does here by default?" and if there is one, choose that alternative as your default because it's more likely to be correct. Sometimes C++ helps you out, it might have a keyword "do_it_right" and you can just default to that, if you feel people might want the C++ default behaviour, feel free to reserve "do_it_wrong" in case people wanted that, but in many cases they will never ask you to implement the C++ behaviour because it's just wrong. Examples: "const" in C++ doesn't mean "constant" it means "immutable", so, make immutable your default and offer "mutable" as the option. "explicit" in C++ makes constructors need an explicit cast to be used for conversion, once again of course you want that by default but feel free to reserve "implicit" in case some people are sure they need the C++ behaviour.

conaclos 4y ago

> Case in point: the new self-hosted compiler is 1.5x faster than the C++ implementation and uses 3x less peak RAM. I am not sure it is comparable: the self-hosted compiler uses a different architecture [1]. [1] https://vimeo.com/649009599/7f1fda43ff https://vimeo.com/649009599/7f1fda43ff

Laremere 4y ago
This is true, but I don't think your point entirely fair either. Zig's design lends itself to writing this style of code. In contrast the usual way(s) C++ is used encourages code that makes these types of optimizations hard/impossible. In practical terms, if you wanted to write fast software, the ergonomics of the language allowing you to use the desired architecture matter a lot. (Also, you're replying to the primary author of Zig and presenter of that talk, if you weren't aware.)
- kaba0 4y ago
  While ergonomics matter, I don’t believe the question is settled at all - for very high performance applications C++ is the answer for a long time to come.

chris2860 4y ago

Hi Andrew, sorry for the unrelated question but where can we find the financial reports of the Zig Software Foundation for 2022? The Finances spreadsheet hasn't been updated for the past half a year: https://docs.google.com/spreadsheets/d/14_ljFHGFXY5NhBhlfjgkO0RZHqeVv04fAmCxw3ZusYc/edit#gid=99104331 https://docs.google.com/spreadsheets/d/14_ljFHGFXY5NhBhlfjgk...

killingtime74 4y ago
Isn’t it quite common to only do financial reports only every quarter, 6 months, yearly?

dilap 4y ago

> * Zig's std lib data structures are incredibly useful, especially compared to the C++ STL. I think elaborating on this could make for a very interesting article. :-) (I have a guess already at one item, which is MultiArrayList, something that kind of blew my mind when I first learned about it, and is in my opinion a very impressive testament to both the power and ease of use of Zig's approach to compile-time computation.)

sekao 4y ago
I didn't even know about it until today, very impressive. Generic SoA in less than 500 lines of userland code... https://github.com/ziglang/zig/blob/master/lib/std/multi_array_list.zig https://github.com/ziglang/zig/blob/master/lib/std/multi_arr...
- jcelerier 4y ago
  SoA in C++ isn't that long, here's my version (which for sure does not have the utility functions defined here though, but is useful enough for me): https://github.com/celtera/ahsohtoa/blob/main/include/ahsohtoa/ahsohtoa.hpp https://github.com/celtera/ahsohtoa/blob/main/include/ahsoht...
  - dilap 4y ago
    That's pretty sweet, I didn't know C++ could do this now! Zig's still got it beat handily in simplicity though -- I think what's really cool about Zig's idea of comp-time evaluation is you get something like the power of C++ with something like the simplicity of C.

labrador 4y ago

> Zig produces smaller, faster binaries than C++ This seems fairly significant to me and makes me wonder how this is possible with all the effort that has gone into optimizing C++

kristoff_it 4y ago
right after that sentence there's a link to a talk that explains one way this is true
- labrador 4y ago
  We can hardly be expected to watch a 46 minute video on "A Practical Guide to Applying Data-Oriented Design" to find our answer. It seems unpromising on the surface.
  - JonChesterfield 4y ago
    Data oriented design is why the thing is faster.
    - labrador 4y ago
      I guess I'll wait for the benchmarks comparing C++ and Zig over a variety of problem solutions to see which one is faster
rk06 4y ago
Because they can't do breaking changes and must live with legacy baggage. While zig can work use modern techniques without such issues
- labrador 4y ago
  This is wrong because you can strip out C++ code you don't need. Green code doesn't need to worry about legacy baggage