[PATCH libdrm] xf86drm: fix compile error for declare i in for loop

[Eric Engestrom]

On Thursday, 2017-05-18 12:10:31 +0100, Emil Velikov wrote:
> On 17 May 2017 at 19:16, Eric Engestrom <eric.engestrom at imgtec.com> wrote:
> > On Wednesday, 2017-05-17 13:58:42 +0000, Yu, Qiang wrote:
> >> Hi Emil,
> >>
> >> I didn't modify the code. I'm using Ubuntu 14.04 gcc 4.8.4, the configure pass but
> >> fail when compile.
> >>
> >> I think my gcc support c99 but needs adding "-std=c99" to enable it, and the configure
> >> script add it into CC variable.
> >
> > From the AC_PROG_CC_C99 docs:
> >> If the C compiler is not in C99 mode by default, try to add an option
> >> to output variable `CC` to make it so.
> >
> > Grrrr...  Add that to the pile of reasons to move away from autotools,
> > I suppose.
> >
> You do realise that cmake, meson and others have similar helper/macros, right?

The macro isn't my issue, the fact that it puts its flags in $CC
instead of $*FLAGS is.
This, as well as the fact that setting $CC beforehand overrides it
(the macro should append), is what I consider a bug in autotools.
(Honestly, I don't remember if cmake/meson/others do the same thing)

> 
> >> When just use "make", it's OK, but my build script uses
> >> "make CC=gcc".
> >>
> >> If you think current state is OK, I can change my build script for that.
> >
> > Yes, I think you should change your build command. It's a shame that
> > autotools has this bug, but we'd like to avoid changing our codebase to
> > work around these, and in this case, it would mean dropping the C99
> > requirement and having to downgrade the whole codebase to something
> > older.
> >
> Again you're miles off, I'm afraid.
> 
> Overrides is a make thing, which allows you to use [normally
> temporary] clever things.
> For example:
> - increase/decrease warning levels of part A in your project
> - change optimisation level of components B

I have no issue with any of this, as long as flags are in $*FLAGS :)

> 
> At the same time, if you do stupid things you get to pick the pieces.
> 
> -Emil