Re: C99 compliance for src/port/snprintf.c

Hi,

On 2018-08-16 10:54:01 +1200, Thomas Munro wrote:
> Really? I am not an MSVC user but I had the impression that their C
> mode (/TC or files named .c) was stuck on C89/C90 as a matter of
> policy, as Herb Sutter explained here (though maybe the situation has
> changed since then):

They revised their position gradually, starting soon after. They claim
full C99 "language" (vs library, which is also pretty complete)
compliance now. I've not yet bothered to fully figure out which version
supports what however. Nor am I really sure about the whole flag thing,
it appears there's a gui element to choose, which we might need to mirror on
the xml level.

A bit of googling shows
https://docs.microsoft.com/en-us/previous-versions/visualstudio/visual-studio-2013/hh409293(v=vs.120)
"
Supports these ISO C99 language features:

_Bool

Compound literals.

Designated initializers.

Mixing declarations with code.
"

which I think is what we roughly would want. So it looks like msvc 2013
might be the relevant requirement.

> That's presumably why cfbot's appveyor build always complains about
> people declaring variables after statements.

IIRC even in older versions there's a flag to allow that.

> To allow that particular language feature, it looks like you have to
> tell it that your .c file is really a C++ program with /TP. But that
> opens a separate can of worms, doesn't it?

Yea, I don't think we want to go there by default soon.

Greetings,

Andres Freund