From: fche@redhat.com (Frank Ch. Eigler)
To: Craig Ringer <craig@2ndquadrant.com>
Cc: systemtap@sourceware.org
Subject: Re: Option to selectively override -Werror to work around new-compiler-version issues
Date: Tue, 18 Aug 2020 15:33:15 -0400 [thread overview]
Message-ID: <87sgcjvjes.fsf@redhat.com> (raw)
In-Reply-To: <CAMsr+YGdMkDMAGeQXgjF0-Hj5+Lxm+GSjM1qL+joTqP1cUK4aw@mail.gmail.com> (Craig Ringer's message of "Mon, 20 Jul 2020 12:03:48 +0800")
craig wrote:
> TL;DR: Would a patch that adds a new "stap" argument that lets you
> selectively disable individual -Werror sub-flags be acceptable? [...]
At one point we actually had a hidden option to block -Werror,
but some fire-breathing monster removed it in commit 2537a8805c.
> The accepted strings would be comma-separated, and confined to the
> [a-z0-9-] pattern to prevent sneaky injection of other flags.
> It doesn't look like it's too hard to implement - I'd be touching main.cxx,
> session.cxx, and buildrun.cxx by the looks.
Sounds like a plausible plan. OTOH, we now have a precedent for
diagnostic suppression via:
#pragma GCC diagnostic ignored "-W......"
which one could add to one's own scripts via a top level embedded-C
block. That might be enough. Or could be a more tasteful way to inject
warning suppression, than to muck with CFLAGS per se.
> (The eBPF runtime is not usable for the sort of userspace probing and
> tracing I use, and I'm often working on long-lived daemon processes, so the
> kernel runtime is my only option.)
(See also the --dyninst runtime.)
> Comments in the code suggest that -Werror cannot be disabled without
> causing problems-unspecified with stapconf.
The stapconf tests depend on the compiler producing a thorough failure
for questionable constructs, so as to suppress automated casting or such
that might hide subtle API changes.
> I didn't find any supported way to inject my own CPPFLAGS or CFLAGS
> via "stap" or "staprun"; I assume that's mainly a security concern?
> [...]
A stap-server will want to suppress these flags, but otherwise not a
security concern.
- FChE
prev parent reply other threads:[~2020-08-18 19:33 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-20 4:03 Craig Ringer
2020-08-18 19:33 ` Frank Ch. Eigler [this message]
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