On Fri, Mar 27, 2015 at 11:13:07AM -0500, Jeff Nelson wrote:
> On Fri, Mar 27, 2015 at 11:01:23AM +0100, Pavel Hrdina wrote:
> > Similar to VIR_EXLUSIVE_FLAGS, it will error out if flag requirement is
> > not met.
> >
> > Signed-off-by: Pavel Hrdina <phrdina@xxxxxxxxxx>
> > ---
> > src/internal.h | 43 +++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 43 insertions(+)
> >
> > diff --git a/src/internal.h b/src/internal.h
> > index eb8d231..6363e58 100644
> > --- a/src/internal.h
> > +++ b/src/internal.h
> > @@ -371,6 +371,49 @@
> > goto LABEL; \
> > }
> >
> > +/* Macros to help dealing with flag requirements. */
> > +
> > +/**
> > + * VIR_REQUIRE_FLAG_RET:
> > + *
> > + * @FLAG1: First flag to be checked.
> > + * @FLAG2: Second flag that is required by first flag.
> > + * @RET: Return value.
> > + *
> > + * Check whether required flag is set. The checked flags are compared
> > + * with flags variable.
> > + *
> > + * This helper does an early return and therefore it has to be called
> > + * before anything that would require cleanup.
> > + */
> > +# define VIR_REQUIRE_FLAG_RET(FLAG1, FLAG2, RET) \
> > + if ((flags & FLAG1) && !(flags & FLAG2)) { \
> > + virReportInvalidArg(ctl, \
> > + _("Flag '%s' is required by flag '%s'"), \
> > + #FLAG2, #FLAG1); \
> > + return RET; \
> > + }
> > +
>
> I recommend encapsulating this within a "do { ... } while (1)"
Oops. "while(0)", not "while (1)".
-Jeff
> statement. The problem is that the macro hides/exposes an -if-
> statement to which an -else- keyword can be bound:
>
> if (something)
> VIR_REQUIRE_FLAG_RET(f1, f2, foo)
> else // matches with -if- inside VIR_REQUIRE_FLAG_RET
> // doesn't execute when you think it does
>
> Note that other macros (see definition of virCheckNonNullArgReturn
> below) follow this practice.
>
> > +/**
> > + * VIR_REQUIRE_FLAG_GOTO:
> > + *
> > + * @FLAG1: First flag to be checked.
> > + * @FLAG2: Second flag that is required by first flag.
> > + * @LABEL: Label to jump to.
> > + *
> > + * Check whether required flag is set. The checked flags are compared
> > + * with flags variable.
> > + *
> > + * Returns nothing. Jumps to a label if required flag is not set.
> > + */
> > +# define VIR_REQUIRE_FLAG_GOTO(FLAG1, FLAG2, LABEL) \
> > + if ((flags & FLAG1) && !(flags & FLAG2)) { \
> > + virReportInvalidArg(ctl, \
> > + _("Flag '%s' is required by flag '%s'"), \
> > + #FLAG2, #FLAG1); \
> > + goto LABEL; \
> > + }
> > +
>
> Same feedback as above.
>
> -Jeff
>
> > # define virCheckNonNullArgReturn(argname, retval) \
> > do { \
> > if (argname == NULL) { \
> > --
> > 2.0.5
> >
> > --
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>
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