4 ms·

Yeah, but then I have to side with the author - how could a compile time only feature which doesn't even introduce new language semantics possibly be affected b

by xg15 4y ago

Yeah, but then I have to side with the author - how could a compile time only feature which doesn't even introduce new language semantics possibly be affected by the multitude of build targets? Unless "it's more complicated than you think" is the catchall answer to any and all proposals for new language features. In which case, how to make progress at all? Also, I find the point about the language being "truly portable" a bit ironic, considering the whole rationale of #embed was that the use case of "embed large chunks of binary data in the executable" was completely non-portable and required adding significant complexity to the build scripts if you were targeting multiple platforms. It's easy to make a language portable on paper if you simply declare the non-portable parts to not be your responsibility. > Everyone in the wg14 who has been around for a while, knows this, and therefore assumes that even the simplest addition will cause problems, even if they cant come up with a reason why. That's not something to be proud of.

quelsolaar 4y ago
> That's not something to be proud of. Its learning from old mistakes. Look at embed as an example. Look how complex it is, dealing with empty files, different ways of opening files, files without lengths, null termination... the list goes on. This is typical of a proposal for C, it starts out simple "why cant i just embed a file in to my code?" and then it gets complicated because the world is complicated. I worry a lot about people loading in text files and forgetting to add null termination to embeds. I would not be surprised if in a few years that provides a big headline on Hacker news, about how that shot someone in the foot and how C isn't to be trusted. The details matter.
- duped 4y ago
  > I worry a lot about people loading in text files and forgetting to add null termination to embeds. I would not be surprised if in a few years that provides a big headline on Hacker news, about how that shot someone in the foot and how C isn't to be trusted. The details matter. The compiler should insert the null terminator if it's not in the embedded file.
  - nyanpasu64 4y ago
    I don't think adding a null terminator is useful for binary files which are not null-terminated strings, and may even have embedded 0 bytes in the middle.
    - duped 4y ago
      sure, but if it's a string that requires it to be null terminated, there's no reason the compiler can't solve that problem
      - remexre 4y ago
        How does the compiler know if an array is a string or not?
        duped 4y ago
        It doesn't have to, you just add a zero byte at the end of the embedded byte sequence in the object file. It's up to the programmer to make the choice how to interpret that. That said for binary embeds you almost always need the length embedded as well, which has been the case for every tool I've used to embed files in object code. You usually get something like const size_t My_FILE_LENGTH = ... ; const uint8_t MY_FILE[] = { ... };
        remexre 4y ago
        > It doesn't have to, you just add a zero byte at the end of the embedded byte sequence in the object file. It's up to the programmer to make the choice how to interpret that. Like, are you proposing that the ideal semantics for `#embed "foo"` if foo contained 0x10 0x20 0x30 0x40 to be to expand to `16, 32, 48, 64, 0`? That seems more annoying than the opposite, given that: > That said for binary embeds you almost always need the length embedded as well, which has been the case for every tool I've used to embed files in object code. You usually get something like TFA demonstrated it by relying on sizeof() of arrays doing the right thing: static_assert((sizeof(sound_signature) / sizeof(*sound_signature)) >= 4, "There should be at least 4 elements in this array."); You'd need to change this to subtract one every time, which sounds more annoying when embedding binary resources than adding the zero to strings would be.
- iainmerrick 4y ago
  I worry a lot about people loading in text files and forgetting to add null termination to embeds. If you really worry about that, why did you vote in favour of this feature (as you stated earlier)?
  - nindalf 4y ago
    He’s just trying to justify why it took 5 years to approve a feature that is so similar to #include.
- rurban 4y ago
  null termination is not to be added to embed. embed adds a const sized buffer of unsigned bytes, not strings. files are not strings, files do contain \0. and I still don't get why embed is so much better than xxd included buffers. it's more convenient sure, but 10x faster?
  - marssaxman 4y ago
    #embed is faster because it skips the parsing step. xxd generates source code tokens, which the parser must then decode back into bytes; embed just reads the bytes directly.
  - riking 4y ago
    Multiple big-O steps faster.
    - account42 4y ago
      That's not how big-O works.

by xg15 4y ago

quelsolaar 4y ago

> That's not something to be proud of. Its learning from old mistakes. Look at embed as an example. Look how complex it is, dealing with empty files, different ways of opening files, files without lengths, null termination... the list goes on. This is typical of a proposal for C, it starts out simple "why cant i just embed a file in to my code?" and then it gets complicated because the world is complicated. I worry a lot about people loading in text files and forgetting to add null termination to embeds. I would not be surprised if in a few years that provides a big headline on Hacker news, about how that shot someone in the foot and how C isn't to be trusted. The details matter.

duped 4y ago
> I worry a lot about people loading in text files and forgetting to add null termination to embeds. I would not be surprised if in a few years that provides a big headline on Hacker news, about how that shot someone in the foot and how C isn't to be trusted. The details matter. The compiler should insert the null terminator if it's not in the embedded file.
- nyanpasu64 4y ago
  I don't think adding a null terminator is useful for binary files which are not null-terminated strings, and may even have embedded 0 bytes in the middle.
  - duped 4y ago
    sure, but if it's a string that requires it to be null terminated, there's no reason the compiler can't solve that problem
    - remexre 4y ago
      How does the compiler know if an array is a string or not?
      - duped 4y ago
        It doesn't have to, you just add a zero byte at the end of the embedded byte sequence in the object file. It's up to the programmer to make the choice how to interpret that. That said for binary embeds you almost always need the length embedded as well, which has been the case for every tool I've used to embed files in object code. You usually get something like const size_t My_FILE_LENGTH = ... ; const uint8_t MY_FILE[] = { ... };
        remexre 4y ago
        > It doesn't have to, you just add a zero byte at the end of the embedded byte sequence in the object file. It's up to the programmer to make the choice how to interpret that. Like, are you proposing that the ideal semantics for `#embed "foo"` if foo contained 0x10 0x20 0x30 0x40 to be to expand to `16, 32, 48, 64, 0`? That seems more annoying than the opposite, given that: > That said for binary embeds you almost always need the length embedded as well, which has been the case for every tool I've used to embed files in object code. You usually get something like TFA demonstrated it by relying on sizeof() of arrays doing the right thing: static_assert((sizeof(sound_signature) / sizeof(*sound_signature)) >= 4, "There should be at least 4 elements in this array."); You'd need to change this to subtract one every time, which sounds more annoying when embedding binary resources than adding the zero to strings would be.
iainmerrick 4y ago
I worry a lot about people loading in text files and forgetting to add null termination to embeds. If you really worry about that, why did you vote in favour of this feature (as you stated earlier)?
- nindalf 4y ago
  He’s just trying to justify why it took 5 years to approve a feature that is so similar to #include.
rurban 4y ago
null termination is not to be added to embed. embed adds a const sized buffer of unsigned bytes, not strings. files are not strings, files do contain \0. and I still don't get why embed is so much better than xxd included buffers. it's more convenient sure, but 10x faster?
- marssaxman 4y ago
  #embed is faster because it skips the parsing step. xxd generates source code tokens, which the parser must then decode back into bytes; embed just reads the bytes directly.
- riking 4y ago
  Multiple big-O steps faster.
  - account42 4y ago
    That's not how big-O works.