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@redhat.com> --- 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)" 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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