Re: [Grep-devel] [platform-testers] new snapshot available: grep-2.25.101-be82

[Paul Eggert]

On 09/27/2016 09:43 AM, Assaf Gordon wrote:
> Would it be possible to consider some older GCC's as still valid
> for automatically enabling warnings ?

I thought about that, but that would mean we'd have to port grep to 
these older compilers when configured with --enable-gcc-warnings. Older 
compilers often generate false alarms and we'd probably have to contort 
the code just to pacify the old bugs. Plus, we'd have to keep a copy of 
GCC 4.8 (or whatever) around just to test whether grep still builds with 
--enable-gcc-warnings. This sounds like more hassle than the warnings 
are worth.

The situation with clang is similar to that with older GCC, for C 
anyway. People can use --enable-gcc-warnings with clang now (as long as 
they don't pester us about the false alarms :-).

For what it's worth I just now tried to build grep with clang 3.8.0 on 
Fedora and ran into several problems, not just --enable-gcc-warnings. 
I'll see if I can fix them without contorting grep too much.

> Effectively this means that developers using stable distributions will
> need to build and install a new compiler, or forgo the warnings (which 
> are very useful).

These developers don't need to forgo the warnings, as they can use 
'./configure --enable-gcc-warnings'.

> there are two 'main()' - not sure if this compiles successfully or not

Ouch, thanks for catching that. I didn't see it because I configured 
long ago with --enable-gcc-warnings (my usual practice) and the rebuild 
picked up that flag. Fixed with the 1st attached patch.

> If we decide to keep this as-is, perhaps it would be helpful to 
> rephrase the error message
> to 'Enabling warnings requires GCC=>6.2' ? 

Sure, I did something like that in the 2nd attached patch. I'd rather 
not put the version number in the diagnostic as that'd be yet another 
place we have to maintain version numbers by hand.

0001-build-port-.git-builds-to-newer-GCC.patch
Description: Source code patch

0002-build-reword-.git-old-GCC-warning.patch
Description: Source code patch