michael@0: #include <wchar.h>
michael@0: 
michael@0: namespace base {
michael@0: 
michael@0: bool IsWprintfFormatPortable(const wchar_t* format) {
michael@0:   for (const wchar_t* position = format; *position != '\0'; ++position) {
michael@0:     if (*position == '%') {
michael@0:       bool in_specification = true;
michael@0:       bool modifier_l = false;
michael@0:       while (in_specification) {
michael@0:         // Eat up characters until reaching a known specifier.
michael@0:         if (*++position == '\0') {
michael@0:           // The format string ended in the middle of a specification.  Call
michael@0:           // it portable because no unportable specifications were found.  The
michael@0:           // string is equally broken on all platforms.
michael@0:           return true;
michael@0:         }
michael@0: 
michael@0:         if (*position == 'l') {
michael@0:           // 'l' is the only thing that can save the 's' and 'c' specifiers.
michael@0:           modifier_l = true;
michael@0:         } else if (((*position == 's' || *position == 'c') && !modifier_l) ||
michael@0:                    *position == 'S' || *position == 'C' || *position == 'F' ||
michael@0:                    *position == 'D' || *position == 'O' || *position == 'U') {
michael@0:           // Not portable.
michael@0:           return false;
michael@0:         }
michael@0: 
michael@0:         if (wcschr(L"diouxXeEfgGaAcspn%", *position)) {
michael@0:           // Portable, keep scanning the rest of the format string.
michael@0:           in_specification = false;
michael@0:         }
michael@0:       }
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: }  // namespace base
michael@0: