Go struct memory layout compared to C | Discord Gophers | Page 1

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this is comically unsafe

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yes, you can definitely do it

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and it should work, most of the time

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but it would be safer to use a real c struct, with cgo

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usually the best approach, when you need to expose this functionality to users, is hiding the C struct unexported behind a go struct, and exposing get/set methods

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if you don't want to do get/set methods you can also have the go struct mirror the fields of the C struct, and then when it comes to calling the C method, construct the C struct locally there, or have the C struct be a field of the go struct, and only synchronize values between them when used

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:)

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i prefer raw cgo, but to each their own

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at runtime..

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like,, you don't know what kind of structs you'll get?

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well, it is and it isn't

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it's doable now, but it's completely unsupported and could break with any update

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how are you constructing go structs at runtime?

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this is definitely an interesting use case

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the safest way to do this is read up on how C constructs structs in memory

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and then "fake" it

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(i am talking out of my ass with this example, i don't know how C actually does it) but let's take this as an example

typedef struct Foo {
  int x;
}

let's say C serializes this as literally just an int

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so you could just turn an int into a byte array, and pass the pointer to that to C

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this gets more and more complex the more stuff is in a struct of course

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and don't even get me started on touples

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lol

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this would be my first impulse anyways, i can not guarantee that this is the best way to do it

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yeah i've had mixed results converting c struct pointers to go structs

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maybe if you exclusively use C datatypes it's a bit safer

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im gonna POC this again and see how robust it is

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maybe you won't need libffi

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it's really doubtful that go would randomly decide to mess with memory layout of structs

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especially since it's been pretty much unchanged for a while now

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yeah you'll likely run into some edge cases but

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for the most part the memory layout seems fine

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seems to be okay shrug

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it's still comically unsafe but,,, almost everything i do is comically unsafe

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i mod unity games with go Hehe

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so as long as you can use C types with reflection it should be fine, if not, that makes things a bit harder

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well, they're not predefined in the reflect package, but you can define them yourself

something like

var CStringType = reflect.TypeOf(C.CString("hi"))

#Go struct memory layout compared to C