[Info-vax] Viable versus ideal programming languages

[Arne Vajhøj]

On 3/25/2022 10:52 AM, Dan Cross wrote:
> In article <623dd2b3$0$700$14726298 at news.sunsite.dk>,
> Arne Vajhøj  <arne at vajhoej.dk> wrote:
>> On 3/25/2022 9:51 AM, Dan Cross wrote:
>>> In article <623dc61c$0$702$14726298 at news.sunsite.dk>,
>>> Arne Vajhøj  <arne at vajhoej.dk> wrote:
>>>> On 3/25/2022 9:16 AM, Dan Cross wrote:
>>>> [snip]
>>>>> Of course, all of this works because the name mangling algorithm
>>>>> is well-specified.
>>>>
>>>> If I read that code correctly then it works because the
>>>> std::arch::asm ... mangled = sym mangled knows what to do.
>>>>
>>>> Which is not general language interop.
>>>
>>> It "knows what to do" because the name mangling algorithm is
>>> well-specified by a generic ABI, which is the point:
>>>
>>> https://itanium-cxx-abi.github.io/cxx-abi/abi.html#mangling
>>>
>>> Rust provides a convenient mechanism to make this trivial.
>>
>> Most mangling schemes are documented.
> 
> Yup.
> 
>> But they are not easily human readable,
> 
> That's true, though over time you do sort of pick it
> up; kinda like Morse code or something.
> 
>> not compatible with
>> each other and tend to not be stable over time.
> 
> That is NOT true.  There's pretty much one that every has
> standardized on now, and it is well-specified.  It "changes over
> time" in the same way that any ABI changes over time: new things
> are added as languages etc evolve, but the baseline behavior is
> durable.

I thought Rust RFC 2603 changed Rust name mangling??

>> Which is why disabling it is a good thing for language
>> interop.
> 
> We're now at the point of arguing semantics.  I gave an example
> where one does not _need_ to disable it; that's all.

But the example was not really language interop as the Rust
compiler did the name mangling for the inline assembler.

>                                                      Strictly
> speaking, it is not necessary to disable mangling for interop;

True.

One can always find the mangled name either by applying documentation or 
by looking at generated code. But that is not good way to code.

> whether one wants to for other reasons (readability) or
> considers it a good idea in general is orthogonal.

But really the interesting/relevant part.

Lots of things are possible. You don't need a compiler
to create a program. It is potentially possible to type
in an EXE file in a hex editor. But nobody would do that.

I hope nobody expose mangled names for external
calling either.

Arne