On Mon, Sep 17, 2018 at 3:37 PM Rene Rivera <grafikrobot_at_[hidden]> wrote:

> On Mon, Sep 17, 2018 at 5:04 PM JF Bastien <cxx_at_[hidden]> wrote:
>
>> On Mon, Sep 17, 2018 at 1:38 PM Rene Rivera <grafikrobot_at_[hidden]>
>> wrote:
>>
>>> On Mon, Sep 17, 2018 at 3:31 PM Tony V E <tvaneerd_at_[hidden]> wrote:
>>>
>>>> Also, if you give me a function called std::compile(), that compiles
>>>> code, it seems I can now write a compiler?
>>>>
>>>> int main(int argc, char ** argv)
>>>> {
>>>> return std::compile(argc, argv);
>>>> }
>>>>
>>>> Wow, that was easy.
>>>> Can the paper explain what I'm misunderstanding? (Or maybe it does
>>>> explain, but I missed it)
>>>>
>>>
>>> That's a correct understanding. And that's the one example I use in my
>>> implementation <
>>> https://github.com/bfgroup/std_cpp/blob/master/example/std_cpp.cpp>. I
>>> do try and explain the goals in the paper. In that it serves a dual
>>> purpose. But mainly it's a way to standardize the compiler options.
>>>
>>
>> Right, otherwise you'd have to do:
>>
>>
>> int main(int argc, char** argv) {
>> std::system((std::string("clang ") + argv[1]).c_str());
>> return 0;
>> }
>>
>>
>> ;-)
>>
>> More seriously, the selection of compiler options you've chosen seem
>> semi-random.
>>
>
> First it's not random :-) It's the minimal to get basic actual compiling
> working and to show highlight some of the differences in link
> compatibility. Second, it's very incomplete. I'll keep adding options as I
> implement them from now until the mailing deadline (and keep implementing
> them afterwards for an R1 paper -- and so on). Third, I hope I can get some
> volunteers to help in adding options.
>
>
>> It would be useful to have a survey of existing compilers and their
>> options, and some criteria to determine which should be supported here and
>> which shouldn't.
>>
>
> Selection criteria is indeed a hard problem. What's actually needed for
> core? And what can be delegated to the vendor specific realm?
>

For context, I've added options in the past, removed some. It's not a big
deal. It would be a big deal if the standard added and removed some. That's
worrying.


Further, what's the expectation of the result of calling this function? Can
>> I actually execute any code? How? Can you make sure that you take into
>> account the restrictions various platforms have, such as requiring code
>> authentication. It goes way beyond linkers.
>>
>
> The proposal doesn't, intentionally, say anything about executing code.
> This is one of those "implementation defined" areas. Just like it is
> currently in the standard. If it's possible to execute code in some manner,
> either indirectly through an std::system equivalent or directly through
> JIT/DLL, is left for the implementor/compiler to document.
>

So a valid implementation always returns true, does nothing?


system seems like a precedent for what you suggest, and in my experience
>> system isn't a precedent people want us to repeat.
>>
>
> "std::system" is what the sample implementation uses.. but it's possible
> you could implement it as a direct library call (easily doable for Clang,
> for example). And ideally production implementations would use something
> more robust than std::system ;-)
>

What's the upside of a library call?

I get the impression you're going down a rabbit hole...

How is the design different from something like this:

https://clang.llvm.org/docs/DriverInternals.html

?

Maybe the code will help explain what I have in mind:

https://github.com/llvm-mirror/clang/blob/master/tools/driver/driver.cpp


 Or, put another way, why can't a Python script be used to frob
command-line parameters in the way you propose? Have there been such tools
in the past? Have they succeeded? What were their approaches?

How is this different from, say, how CMake does things? It tries to
abstract away some flags and it does so much more than your proposal. Why
would I want your proposal over CMake?

As I see it, the proposal is missing a bunch of context and related
research. I'd like to see more to understand why it's the right tool for
users of C++. I'm not convinced this tool needs to be usable from C++.