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Thank you, Its also worth remembering that a lot of higher level languages have runtimes / VMs are implemented in C. Web applications rely heavily on databases

Thank you, Its also worth remembering that a lot of higher level languages have runtimes / VMs are implemented in C. Web applications rely heavily on databases, java script VM, network-stacks, system calls and operating system features, all of which are impemented in C. If you are a software developer and want to do something about climate change, consider becomming a compiler engineer. If you manage to get a couple of tenths of a percent performance increase in one of the big compilers during your career, you will have materially impacted global warming. Compiler engineers are the unsung heroes of software engineering.

ErikCorry 4y ago
No JavaScript VM is implemented in C. They are all written in a language that's a bit like C++ but has no exceptions and relies on lots of compiler behaviour that is not defined by the C++ standard.
- woodruffw 4y ago
  Hm? I can think of two pure C JS engines off the top of my head: Duktape and Elk. I believe Samsung or another vendor also has their own; they’re all somewhat common in the embedded space.
  - ErikCorry 4y ago
    Fair. I'm not familiar with the tiny JS VMs. But really the main point stands: It's not possible to build a decent GC without violating strict aliasing so C and C++ as standardized are not suitable for this task.
- xyzzy_plugh 4y ago
  I guess this doesn't exist then: https://bellard.org/quickjs/ https://bellard.org/quickjs/
  - astrange 4y ago
    This is not written in C if it doesn’t pass UBSan/ASan/Frama-C and co. It’s written in a language that just happens to look like C.
    - icedchai 4y ago
      Close enough. Will you claim the Linux kernel isn't C because it's compiled with -fno-strict-overflow and -fno-strict-aliasing ?
      - astrange 4y ago
        Yes, that’s why it only supports specific C compilers. Anything that includes its own memory allocator (that doesn’t call malloc()) is probably not implemented in standardized C.
        icedchai 4y ago
        It’s still “C”, even if it’s a specific dialect. Vendor specific C extensions have existed forever.
    - saagarjha 4y ago
      This is incredibly pedantic, even for Hacker News. I suspect you do not wish to be responded to like this in general, so I struggle to see why it is appropriate here.
      - ErikCorry 4y ago
        The point is that if you are programming in a C dialect or a C++ dialect you will be told this again and again. Ask a question on Stackoverflow about code that requires nonstandard flags or uses UB. You will be told your program is not really in C/C++ and that your question makes no sense. You will be lectured on nasal demons for the nth time. File a bug against a compiler asking the optimizers to back off using UB to subvert the intentions of the programmer and you will be told there's no way to even know the intentions of the programmer given that the standards don't apply. So we can all move to a nomenclature where C is used loosely to indicate a family of languages, once of which happens to be standardized. I'd be happy to do that. But let's not bait and switch, using standards pedantry to dismiss feature requests and bug reports, but then turning around and saying C/C++ is suitable for implementing runtimes of other languages when nothing can really be achieved in that space without going beyond the language spec. And really in 2022 runtimes, JITs, GCs should be the primary use of C/C++. Many other uses (systems software, compilers, desktop apps, phone apps) are not suited for C/C++ due to security, stability, ease of development and newer languages that make more sense for these domains.
thefaux 4y ago
> If you manage to get a couple of tenths of a percent performance increase in one of the big compilers during your career, you will have materially impacted global warming. I've heard this kind of claim a number of times and I think it's more complicated than the crude statistical measurement makes it sound. Personally, I think that most programs are not run frequently enough to matter from an emissions perspective. For programs that are, like ML training programs, users will just train more data if the algorithms are faster so most energy efficiencies will get wiped out by the increased usage. Even if that theory is wrong, what if there is a language that is 10% better than C for 95% of common C use cases? Wouldn't it be better for compiler engineers to focus on developing that language than micro-optimizing C?

ErikCorry 4y ago

No JavaScript VM is implemented in C. They are all written in a language that's a bit like C++ but has no exceptions and relies on lots of compiler behaviour that is not defined by the C++ standard.

woodruffw 4y ago
Hm? I can think of two pure C JS engines off the top of my head: Duktape and Elk. I believe Samsung or another vendor also has their own; they’re all somewhat common in the embedded space.
- ErikCorry 4y ago
  Fair. I'm not familiar with the tiny JS VMs. But really the main point stands: It's not possible to build a decent GC without violating strict aliasing so C and C++ as standardized are not suitable for this task.
xyzzy_plugh 4y ago
I guess this doesn't exist then: https://bellard.org/quickjs/ https://bellard.org/quickjs/
- astrange 4y ago
  This is not written in C if it doesn’t pass UBSan/ASan/Frama-C and co. It’s written in a language that just happens to look like C.
  - icedchai 4y ago
    Close enough. Will you claim the Linux kernel isn't C because it's compiled with -fno-strict-overflow and -fno-strict-aliasing ?
    - astrange 4y ago
      Yes, that’s why it only supports specific C compilers. Anything that includes its own memory allocator (that doesn’t call malloc()) is probably not implemented in standardized C.
      - icedchai 4y ago
        It’s still “C”, even if it’s a specific dialect. Vendor specific C extensions have existed forever.
  - saagarjha 4y ago
    This is incredibly pedantic, even for Hacker News. I suspect you do not wish to be responded to like this in general, so I struggle to see why it is appropriate here.
    - ErikCorry 4y ago
      The point is that if you are programming in a C dialect or a C++ dialect you will be told this again and again. Ask a question on Stackoverflow about code that requires nonstandard flags or uses UB. You will be told your program is not really in C/C++ and that your question makes no sense. You will be lectured on nasal demons for the nth time. File a bug against a compiler asking the optimizers to back off using UB to subvert the intentions of the programmer and you will be told there's no way to even know the intentions of the programmer given that the standards don't apply. So we can all move to a nomenclature where C is used loosely to indicate a family of languages, once of which happens to be standardized. I'd be happy to do that. But let's not bait and switch, using standards pedantry to dismiss feature requests and bug reports, but then turning around and saying C/C++ is suitable for implementing runtimes of other languages when nothing can really be achieved in that space without going beyond the language spec. And really in 2022 runtimes, JITs, GCs should be the primary use of C/C++. Many other uses (systems software, compilers, desktop apps, phone apps) are not suited for C/C++ due to security, stability, ease of development and newer languages that make more sense for these domains.

thefaux 4y ago

> If you manage to get a couple of tenths of a percent performance increase in one of the big compilers during your career, you will have materially impacted global warming. I've heard this kind of claim a number of times and I think it's more complicated than the crude statistical measurement makes it sound. Personally, I think that most programs are not run frequently enough to matter from an emissions perspective. For programs that are, like ML training programs, users will just train more data if the algorithms are faster so most energy efficiencies will get wiped out by the increased usage. Even if that theory is wrong, what if there is a language that is 10% better than C for 95% of common C use cases? Wouldn't it be better for compiler engineers to focus on developing that language than micro-optimizing C?