Hi,
 
When tagging glibc2.5 source code, if finding tag: vfprintf, it does show the correct real definition of the function at all.
 
Here is the global result:
vfprintf           70 glibc25/libio/bits/stdio2.h # define vfprintf(stream, format, ap) \
vfprintf           43 glibc25/stdio-common/printf-prs.c # define vfprintf vfwprintf
vfprintf           68 glibc25/stdio-common/vfprintf.c # define vfprintf _IO_vfprintf_internal
vfprintf           84 glibc25/stdio-common/vfprintf.c # define vfprintf _IO_vfwprintf
vfprintf         2188 glibc25/stdio-common/vfprintf.c #undef vfprintf
vfprintf            5 glibc25/sysdeps/ieee754/ldbl-opt/nldbl-vfprintf.c vfprintf (FILE *s, const char *fmt, va_list ap)
The actual line should be: 182 vfprintf (FILE *s, const CHAR_T *format, va_list ap)
 
I used 5.8.2 and 5.9 version to get this.
 
Thanks