On Tue, Nov 25, 2025 at 04:05:06PM +0100, Ján Tomko wrote:
> On a Tuesday in 2025, Michal Prívozník wrote:
> > On 11/25/25 15:10, Daniel P. Berrangé via Devel wrote:
> > > On Tue, Nov 25, 2025 at 02:54:20PM +0100, Ján Tomko via Devel wrote:
> > > > On a Tuesday in 2025, Peter Krempa via Devel wrote:
> > > > > From: Peter Krempa <[email protected]>
> > > > >
> > > > > 'char *tmp' is assigned from calling 'strrchr' on a 'const char *'.
> > > > > New
> > > > > clang in fedora doesn't like it. Make 'tmp' const.
> > > > >
> > > > > Signed-off-by: Peter Krempa <[email protected]>
> > > > > ---
> > > > >
> > > > > https://gitlab.com/MichalPrivoznik/libvirt/-/jobs/12208300313
> > > > >
> > > >
> > > > I was hoping the link would show a fixed pipeline :)
> > >
> > > I'm rather curious how clang decides to trigger that warning given
> > > the libc header file declares the return value non-const
> > >
> > > extern char *strchr (const char *__s, int __c)
> > > __THROW __attribute_pure__ __nonnull ((1));
> > >
> > > It seems like clang has special-cased strchr/strrchr to enforce
> > > the const return for const input.
> >
> > Well, it also triggers in places like:
> >
> > ../src/rpc/virnetsshsession.c:223:18: error: assigning to 'char *' from
> > 'const char *' discards qualifiers
> > [-Werror,-Wincompatible-pointer-types-discards-qualifiers]
> > 223 | if ((tmp = strrchr(askcred[i].prompt, ':')))
> > | ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >
> >
> > And just to give you context around the line:
> >
> > if ((tmp = strrchr(askcred[i].prompt, ':')))
> > *tmp = '\0';
> >
>
> Well, the prompt is defined as const char*:
We just created askcred[i].prompt from g_strdup a line earlier
so it is safe. None the less this is bad practice - we should
use an intermediate variable to strip the ':', and only assign
to the struct once done.
>
> struct _virConnectCredential {
> int type; /* One of virConnectCredentialType constants */
> const char *prompt; /* Prompt to show to user */
> const char *challenge; /* Additional challenge to show */
> const char *defresult; /* Optional default result */
> char *result; /* Result to be filled with user response (or defresult) */
> unsigned int resultlen; /* Length of the result */
> };
>
> Jano
>
> > So I'd rather this patch is NOT merged and CLang is fixed instead.
> >
> > Michal
> >
With regards,
Daniel
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