From: Jason Merrill <jason@redhat.com>
To: Jakub Jelinek <jakub@redhat.com>, Jonathan Wakely <jwakely@redhat.com>
Cc: gcc@gcc.gnu.org
Subject: Re: [RFC] c++, libstdc++: Default make check vs. tests for newest C++ standard
Date: Wed, 19 Oct 2022 09:10:48 -0400 [thread overview]
Message-ID: <2bfe4f0a-84cc-aae8-1834-6dff3918810a@redhat.com> (raw)
In-Reply-To: <Y0+36fGnYINE/VJN@tucnak>
On 10/19/22 04:40, Jakub Jelinek wrote:
> Hi!
>
> The screw-up on my side with libstdc++ testing (tested normally rather
> than in C++23 mode) makes me wonder if we couldn't tweak the default
> testing.
> Dunno what libstdc++ testing normally does (just C++17?), make check-g++
> tests by default { 98, 14, 17, 20 } (and I regularly use
> GXX_TESTSUITE_STDS=98,11,14,17,20,2b in environment but that doesn't
> cover libstdc++ I guess).
> When adding tests for upcoming C++ version, one always has a dilemma
> whether to use explicit // { dg-options "-std=c++2b" }
> or -std=gnu++2b and similar, then the test works in all modes, but it might
> be forgotten later on to be converted into // { dg-do whatever { target c++23 } }
> test so that when 23 is tested by default and say 26 or 29 appears too,
> we test it also in those modes, or just go with
> // { dg-do whatever { target c++23 } }
> which has the disadvantage that it is skipped when testing by default and
> one only tests it if he asks for the newer version.
>
> I wonder if we couldn't for the default testing (when one doesn't
> specify GXX_TESTSUITE_STDS or uses make check-c++-all and similar)
> improve things a little bit by automatically treat those
> // { dg-do whatever { target c++23 } }
> tests as // { dg-options "-std=c++2b" }.
That would be great.
> g++-dg.exp has:
> # If the testcase specifies a standard, use that one.
> # If not, run it under several standards, allowing GNU extensions
> # if there's a dg-options line.
> if ![search_for $test "-std=*++"] {
> if [search_for $test "dg-options"] {
> set std_prefix "-std=gnu++"
> } else {
> set std_prefix "-std=c++"
> }
>
> # See g++.exp for the initial value of this list.
> global gpp_std_list
> if { [llength $gpp_std_list] > 0 } {
> set std_list $gpp_std_list
> } else {
> set std_list { 98 14 17 20 }
> }
> set option_list { }
> foreach x $std_list {
> # Handle "concepts" as C++17 plus Concepts TS.
> if { $x eq "concepts" } then { set x "17 -fconcepts"
> } elseif { $x eq "impcx" } then { set x "23 -fimplicit-constexpr" }
> lappend option_list "${std_prefix}$x"
> }
> } else {
> set option_list { "" }
> }
>
> set nshort [file tail [file dirname $test]]/[file tail $test]
>
> foreach flags_t $option_list {
> verbose "Testing $nshort, $flags $flags_t" 1
> dg-test $test "$flags $flags_t" ${default-extra-flags}
> }
> so I wonder if in the set std_list { 98 14 17 20 } spot we couldn't do
> something like special search_for for "{ dg-do * { target c++23 } }"
> and if so, set std_list { 2b } instead of set std_list { 98 14 17 20 }?
> It wouldn't handle more complex cases like
> // { dg-do compile { target { c++23 && { aarch64*-*-* powerpc64le*-*-linux* riscv*-*-* s390*-*-* sparc*-*-linux* } } } }
> but at least for the majority of tests for the new language version
> it would run them even in default testing where they'd be otherwise
> skipped (we'd cycle over 98 14 17 20 only to see it doesn't satisfy any of
> them).
> If we wanted to go even further, we could handle similarly say c++11_only
> tests.
>
> What do you think?
>
> Jakub
>
prev parent reply other threads:[~2022-10-19 13:10 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-19 8:40 Jakub Jelinek
2022-10-19 8:54 ` Jonathan Wakely
2022-10-19 13:10 ` Jason Merrill [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2bfe4f0a-84cc-aae8-1834-6dff3918810a@redhat.com \
--to=jason@redhat.com \
--cc=gcc@gcc.gnu.org \
--cc=jakub@redhat.com \
--cc=jwakely@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).