On Apr 5, 2010, at 8:20 AM, Benjamin Kosnik wrote:
>
> Hello all!
>
> I've put up a short diagnostics comparison between gcc, icc, and
> clang. It is my plan to update this with major revisions to individual
> compilers.
>
> Included are most of the outstanding bugzilla requests with the
> "diagnostic" keyword. However, I am looking for help! Please send me
> code samples that frustrate, obfuscate, and annoy.
>
> In particular, I am looking for template instantiation issues such as
> c++/41884, but hopefully something in a deliciously small snippet. No
> doubt other C++ hackers have particular annoyances.
>
> I'm also looking for guidance on how to rank the priority of these
> issues. Is there some way to tell what the biggest annoyance is?
>
> http://people.redhat.com/bkoz/diagnostics/diagnostics.html
This is a great resource Benjamin, thanks for putting it together!
Some random thoughts if you ever regenerate this:
1) the caret diagnostics would be easier to understand in the output if
formatted with a <pre> or <tt> tag.
2) The clang invocations don't need -fcaret-diagnostics -fshow-source-location
-fdiagnostics-fixit-info because they are the default.
3) It's best to not pass -fdiagnostics-print-source-range-info unless you're
looking for machine interpretable output. This flag adds things like
{3:29-3:32} which are useful to a machine, but otherwise just clutter the
output up.
4) It looks like ICC defaults to a number of coding standards types of checks,
e.g. "access control not specified". I don't know if it is possible to turn
those off, but they seem to just be noise for the purposes of this comparison.
5) There are a couple cases of GCC rejecting valid code (e.g. 19377), or which
there may be some debate about (19538) it might be worth pointing this out.
*shrug*
6) My understanding was that GCC's complex extension in C++ mode is supposed to
work like C99 _Complex. If so, 41895 looks like a GCC bug. I don't know if
C++'0x affects this though.
7) There are some clang bugs here. Access control is not yet enabled by
default (affects 20397, 39728), and a variety of other bugs (affects 14283,
38612). I file Clang PR#6782/6783 to track these.
Thanks again for putting this together,
-Chris
