Look into __VA_OPT__ for C23

[duarm]

Feature Request

What is the nature of this request?

• Change in source code details (names of variables, functions, parameters, etc)

Is your feature request related to a problem? Please describe.

cmc log functions from log.h, cmc_log_trace for example, are defined as:

#define cmc_log_trace(fmt, ...) cmc_log(CMC_LOG_TRACE, __FILE__, __func__, __LINE__, fmt, ##__VA_ARGS__)

##__VA_ARGS__ is supported by most compilers, but still non-standard, -pedantic issues a warning about it.

C23 solves the problem by introducing the __VA_OPT__ preprocessor. So this is the C23 solution:

#define cmc_log_trace(fmt, ...) cmc_log(CMC_LOG_TRACE, __FILE__, __func__, __LINE__, fmt __VA_OPT__(,)  __VA_ARGS__)

Full C23 support is yet to be available, so not a high priority.

Describe the solution you'd like

Detect the version via __STDC_VERSION__, and use the standard solution if C23 or later.