verify_format_msvc.h

#pragma once

// ENABLE_PRINTF_VERIFY_CHECK_ON_MSVC
//
// Microsoft doesn't provide a way to annoate custom-rolled user printf() functions for static analysis.
// Well, ok -- it does provide _Printf_format_string_ but that's only effective when using the Code Analysis
// tool which is both incrediously slow and generates a hundred false positives for every valid issue. In
// other words, useless.
//
// The upside is MSVC does perform automatic lightweight static analysis on printf() builtin functions as part
// of the regular build process.  So I did a horrible thing and I built a macro that fake-calls MSVC's snprintf()
// on the input string, implemented as the second half of a nullified conditional such that it never _actually_
// gets run. All tokens from the format macro do get pasted twice as part of this process, though only one of
// the pastes is reachable.  Behavior of the __COUNTER__ macro in this case would change.  No other program
// behavior should be affected. --jstine
//
// Usage example:
//  #define myFooPrintf(fmt, ...)    (VERIFY_PRINTF_ON_MSVC(fmt, __VA_ARGS__), _myFooPrintf(fmt, ## __VA_ARGS__))
//

#if !defined(ENABLE_PRINTF_VERIFY_CHECK_ON_MSVC)
#   if defined(_MSC_VER)
#       define ENABLE_PRINTF_VERIFY_CHECK_ON_MSVC   1
#   else
#       define ENABLE_PRINTF_VERIFY_CHECK_ON_MSVC   0
#   endif
#endif

#if !defined(VERIFY_PRINTF_ON_MSVC)
#   if ENABLE_PRINTF_VERIFY_CHECK_ON_MSVC
#       define VERIFY_PRINTF_ON_MSVC(...)   (0 && snprintf(nullptr, 0, ## __VA_ARGS__))
#       if defined(__cplusplus)
            // in C++ we can allow macros where-in the format parameter is optional, typical of macros that
            // translate an empty format into a newline or such.
            // (ex, myPrintLine() being equivalent to myPrintLine(""))
            static inline int snprintf(const char* fmt, int len) {
                return 0;
            }
#       endif
#   else
#       define VERIFY_PRINTF_ON_MSVC(...)   (0)
#   endif
#endif