[libvirt] [PATCH v2 1/2] Introduce virCheckFlags for consistent flags checking

The idea is that every API implementation in driver which has flags parameter should first call virCheckFlags() macro to check the function was called with supported flags: virCheckFlags(VIR_SUPPORTED_FLAG_1 | VIR_SUPPORTED_FLAG_2 | VIR_ANOTHER_SUPPORTED_FLAG, -1); The error massage which is printed when unsupported flags are passed looks like: invalid argument in virFooBar: unsupported flags (0x2) Where the unsupported flags part only prints those flags which were passed but are not supported rather than all flags passed. --- src/internal.h | 23 +++++++++++++++++++++++ 1 files changed, 23 insertions(+), 0 deletions(-) diff --git a/src/internal.h b/src/internal.h index 2e73210..12e9a1f 100644 --- a/src/internal.h +++ b/src/internal.h @@ -191,4 +191,27 @@ fprintf(stderr, "Unimplemented block at %s:%d\n", \ __FILE__, __LINE__); +/** + * virCheckFlags: + * @supported: an OR'ed set of supported flags + * @retval: return value in case unsupported flags were passed + * + * Returns nothing. Exits the caller function if unsupported flags were + * passed to it. + */ +# define virCheckFlags(supported, retval) \ + do { \ + if ((flags & ~(supported))) { \ + virReportErrorHelper(NULL, \ + VIR_FROM_THIS, \ + VIR_ERR_INVALID_ARG, \ + __FILE__, \ + __FUNCTION__, \ + __LINE__, \ + _("%s: unsupported flags (0x%x)"), \ + __FUNCTION__, flags & ~(supported)); \ + return retval; \ + } \ + } while (0) + #endif /* __VIR_INTERNAL_H__ */ -- 1.7.0.4