6 ms·

Memory safety is a pain point of C, and Zig doesn't fix that. There is no free lunch: you either accept garbage collection or deal with something that resembles

Memory safety is a pain point of C, and Zig doesn't fix that. There is no free lunch: you either accept garbage collection or deal with something that resembles the borrow checker.

kristoff_it 5y ago
You could build the same argument for all other types of correctness: either your program is formally validated to be correct, or it's broken. While there is some truth to that, if that's the only analysis you're willing to do, then you're going to fail spectacularly hard at recognizing the advantages of TypeScript over JS, for example. Zig and C share a similar relationship across many axes, including memory safety.
pjmlp 5y ago
From my point of view in terms of memory safety with Zig, we could just use Modula-2 or FreePascal/Delphi instead, but they aren't as fashionable.
- speed_spread 5y ago
  As much as I love Delphi, the language syntax hasn't aged well. Single pass compilation was great to have in the 1980's but nowadays even the humblest Raspberry Pi will chew through thousand of lines of C++ and link an optimized executable within seconds. We deserve and can afford a lot more comfort than Pascal (and siblings) provides. Incidentally, modern language ergonomics also adds much in the way of coding safety, making usage of explicit allocation control a more manageable problem than it was 30 years ago.
  - pjmlp 5y ago
    Indeed, and that is why for me modern language ergonomics is a synonym for Swift, C#, Nim, D, and Rust. For Zig to be part of that list, a story for use-after-free must exist as well. Others won't agree with me, and that is fine, different strokes for different folks.
_vvhw 5y ago
I believe Zig takes a more nuanced and balanced approach to memory safety as a spectrum, rather than the extremes you present of either GC or borrow checker. For example, Zig offers spatial memory safety, and provides test allocators to catch temporal memory safety issues. That's already an order of magnitude improvement over C. Memory safety is also just one aspect of safety, whereas sometimes programmers conflate the two. It's important, but things like checked arithmetic should also be right up there, and should be enabled by default in safe build modes. I think Zig's approach here is also spot on, having worked a little in security, where an integer overflow can be almost as dangerous as a buffer overflow. Yet I don't see many other languages taking checked arithmetic as seriously as Zig does.
- pjmlp 5y ago
  Ada, Modula-2 and Object Pascal, minus compile time execution that they lack, and you have Zig almost 40 years ago. Sad that we have to go in circles to keep programming fashion going, instead of adopting best practices from the get go.
  - deleted 5y ago
    [deleted]
  - kristoff_it 5y ago
    A language isn't just a compiler and a spec. I don't know the full history of all these projects, but IIRC Ada's compiler wasn't free for a long time. How you structure the financials and the community around the language has also a gigantic impact on the final result, and this is an area where Zig bringing to the table something completely new. https://ziglang.org/zsf/ https://ziglang.org/zsf/
    - pjmlp 5y ago
      Although most people associate Object Pascal to Borland due to the Turbo Pascal branding done by them, the language was originally created to write Lisa OS (Clascal), and then when the project got replaced by Mac OS, with the help of Niklaus Wirth input, Clascal became Object Pascal and was the main language until the C++ rewrite that took place in the early 90's. Outside Apple computers, the dialects created by Borland gained such following, specially in Europe, that Turbo Pascal became the official Pascal dialect, even though Extended Pascal fixed most of the original design flaws. Naturally they going enterpreisy lost the crowd to VB and VC++ folks (later .NET). Modula-2 did have some nice offerings, specially on Amiga, but on the PC and Mac, Turbo/Object Pascal made it irrelevant as it offered all the improvements Modula-2 brought to the table (no one cared about co-routines on home computers back then). Ada was the only one from those that yeah, actually quite expensive, and I think only SGI and SUN had UNIX compilers for them, with HP having BASIC and Pascal compilers for their OSes. Then there was the Amsterdam Compiler Kit, the "LLVM" for the 1980's, which had support for C, Pascal, Modula-2, Occam, and BASIC. Looking forward to see how Zig evolves, specially regarding issues like #2301.
deleted 5y ago
[deleted]
flohofwoe 5y ago
Zig fixes many more memory safety issues than C or C++ though, simply by being less "sloppy" and enforcing more correctness (e.g. no implicit type conversions, no over/underflows, proper range-checked arrays and slices etc...) - IME most memory corruption issues in C and C++ are actually secondary effects of such simple correctness issues. Zig just isn't quite as "extremist" as Rust (also, Rust is a great language for writing a sandbox, but if a memory-safe language must be used inside the sandbox to prevent damage outside the sandbox, then it simply isn't a sandbox.
- pcwalton 5y ago
  All of these are available and widely used in C++ (for example [1]). They are not enough. [1]: https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html#available-checks https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html#...
  - flohofwoe 5y ago
    "Widely used" might be a bit of an exaggeration, MSVC only added address sanitizer support very recently but doesn't support any of the other sanitizers, and none of the sanitizers are enabled by default in Clang.
    - pcwalton 5y ago
      The biggest companies on the planet with massive C++ codebases are all very aware of the clang sanitizers and use them regularly. UBSan has far more deployment than Zig.

Memory safety is a pain point of C, and Zig doesn't fix that. There is no free lunch: you either accept garbage collection or deal with something that resembles the borrow checker.

kristoff_it 5y ago

You could build the same argument for all other types of correctness: either your program is formally validated to be correct, or it's broken. While there is some truth to that, if that's the only analysis you're willing to do, then you're going to fail spectacularly hard at recognizing the advantages of TypeScript over JS, for example. Zig and C share a similar relationship across many axes, including memory safety.

pjmlp 5y ago

From my point of view in terms of memory safety with Zig, we could just use Modula-2 or FreePascal/Delphi instead, but they aren't as fashionable.

speed_spread 5y ago
As much as I love Delphi, the language syntax hasn't aged well. Single pass compilation was great to have in the 1980's but nowadays even the humblest Raspberry Pi will chew through thousand of lines of C++ and link an optimized executable within seconds. We deserve and can afford a lot more comfort than Pascal (and siblings) provides. Incidentally, modern language ergonomics also adds much in the way of coding safety, making usage of explicit allocation control a more manageable problem than it was 30 years ago.
- pjmlp 5y ago
  Indeed, and that is why for me modern language ergonomics is a synonym for Swift, C#, Nim, D, and Rust. For Zig to be part of that list, a story for use-after-free must exist as well. Others won't agree with me, and that is fine, different strokes for different folks.

_vvhw 5y ago

I believe Zig takes a more nuanced and balanced approach to memory safety as a spectrum, rather than the extremes you present of either GC or borrow checker. For example, Zig offers spatial memory safety, and provides test allocators to catch temporal memory safety issues. That's already an order of magnitude improvement over C. Memory safety is also just one aspect of safety, whereas sometimes programmers conflate the two. It's important, but things like checked arithmetic should also be right up there, and should be enabled by default in safe build modes. I think Zig's approach here is also spot on, having worked a little in security, where an integer overflow can be almost as dangerous as a buffer overflow. Yet I don't see many other languages taking checked arithmetic as seriously as Zig does.

pjmlp 5y ago
Ada, Modula-2 and Object Pascal, minus compile time execution that they lack, and you have Zig almost 40 years ago. Sad that we have to go in circles to keep programming fashion going, instead of adopting best practices from the get go.
- deleted 5y ago
  [deleted]
- kristoff_it 5y ago
  A language isn't just a compiler and a spec. I don't know the full history of all these projects, but IIRC Ada's compiler wasn't free for a long time. How you structure the financials and the community around the language has also a gigantic impact on the final result, and this is an area where Zig bringing to the table something completely new. https://ziglang.org/zsf/ https://ziglang.org/zsf/
  - pjmlp 5y ago
    Although most people associate Object Pascal to Borland due to the Turbo Pascal branding done by them, the language was originally created to write Lisa OS (Clascal), and then when the project got replaced by Mac OS, with the help of Niklaus Wirth input, Clascal became Object Pascal and was the main language until the C++ rewrite that took place in the early 90's. Outside Apple computers, the dialects created by Borland gained such following, specially in Europe, that Turbo Pascal became the official Pascal dialect, even though Extended Pascal fixed most of the original design flaws. Naturally they going enterpreisy lost the crowd to VB and VC++ folks (later .NET). Modula-2 did have some nice offerings, specially on Amiga, but on the PC and Mac, Turbo/Object Pascal made it irrelevant as it offered all the improvements Modula-2 brought to the table (no one cared about co-routines on home computers back then). Ada was the only one from those that yeah, actually quite expensive, and I think only SGI and SUN had UNIX compilers for them, with HP having BASIC and Pascal compilers for their OSes. Then there was the Amsterdam Compiler Kit, the "LLVM" for the 1980's, which had support for C, Pascal, Modula-2, Occam, and BASIC. Looking forward to see how Zig evolves, specially regarding issues like #2301.

deleted 5y ago

[deleted]

flohofwoe 5y ago

Zig fixes many more memory safety issues than C or C++ though, simply by being less "sloppy" and enforcing more correctness (e.g. no implicit type conversions, no over/underflows, proper range-checked arrays and slices etc...) - IME most memory corruption issues in C and C++ are actually secondary effects of such simple correctness issues. Zig just isn't quite as "extremist" as Rust (also, Rust is a great language for writing a sandbox, but if a memory-safe language must be used inside the sandbox to prevent damage outside the sandbox, then it simply isn't a sandbox.

pcwalton 5y ago
All of these are available and widely used in C++ (for example [1]). They are not enough. [1]: https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html#available-checks https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html#...
- flohofwoe 5y ago
  "Widely used" might be a bit of an exaggeration, MSVC only added address sanitizer support very recently but doesn't support any of the other sanitizers, and none of the sanitizers are enabled by default in Clang.
  - pcwalton 5y ago
    The biggest companies on the planet with massive C++ codebases are all very aware of the clang sanitizers and use them regularly. UBSan has far more deployment than Zig.