Re: [PATCH] configure.ac: drop unnecessary gnu99 extension checks

[Adrian Ratiu <adrian.ratiu@collabora.com>]

Hi Mark,

On Mon, 23 Aug 2021, Mark Wielaard <mark@klomp.org> wrote:
> Hi Adrian, 
> 
> On Tue, Aug 10, 2021 at 03:56:51PM +0300, Adrian Ratiu via 
> Elfutils-devel wrote: 
>> So in the interest of enabling Clang builds we remove the only 
>> remaining blocker: the configure checks for nested functions 
>> and variable length arrays which are also unused. 
> 
> Can we just remove the whole configure test? And change the 
> AC_PROG_CC to AC_PROG_CC_C99?

Yes, I think we can do that.
 
> 
> The patch doesn't update the comments about what is being 
> tested, and the only thing being tested now is Mixed 
> Declarations and Code, which is a standard part of C99.

Good catch. I'll update and send a v2.
 
> 
> Have you tried running make check with an alternative compiler? 
> There are a couple of "self tests" which run the code on the 
> just produced binaries and it would be interesting to know 
> whether or not all tests pass.

I did comparative builds within the Gentoo/ChromeOS build 
environments with the GNU/GCC 10.2 and LLVM/Clang 13.0 toolchains.

With GCC:

# TOTAL: 224 PASS:  214 SKIP:  7 XFAIL: 0 FAIL:  3 XPASS: 0 ERROR: 
# 0 

With Clang:

# TOTAL: 224 PASS:  212 SKIP:  7 XFAIL: 0 FAIL:  5 XPASS: 0 ERROR: 
# 0 

The two tests which failed are run-strip-strmerge.sh and 
run-reverse-sections-self.sh because the `.gnu.version` is 
invalid.

Links are below for the gcc [1] vs clang [2] test-suite.logs.

[1] 
https://drive.google.com/file/d/1uQSHarIQwA07fIih0ZHHt8zfim_BWRYP/view?usp=sharing
[2] 
https://drive.google.com/file/d/1q7iGXjutyoLgM4iOm_rFMVxT11dnwpt5/view?usp=sharing

Thanks,
Adrian

>
> Thanks,
>
> Mark