[Bug preprocessor/19309] New: Wrong documentation of predefined __GNUC__ with cpp invocation

["dannysmith at users dot sourceforge dot net" <gcc-bugzilla at gcc dot gnu dot org>]

Hi, 
According to documentation of preprocessor (cpp.texi:1934)
the predefined macros 
 __GNUC__
 __GNUC_MINOR__
 __GNUC_PATCHLEVEL__

"are defined only when the entire compiler is in use; if you invoke the
 preprocessor directly, they are not defined."


But, 
> touch foo.c
> cpp -dM -E foo.c | grep GNUC

produces 
#define __GNUC_PATCHLEVEL__ 0
#define __GNUC__ 4
#define __GNUC_MINOR__ 0

Same behaviour is observed on 3.4.4.

Macros are also defined with cpp -traditional-cpp.

Should the documentation be modified?
Or is there any reason _not_ to define __GNUC__ when invoking cpp.
Danny

-- 
           Summary: Wrong documentation of predefined __GNUC__  with cpp
                    invocation
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: preprocessor
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dannysmith at users dot sourceforge dot net
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-mingw32
  GCC host triplet: i686-pc-mingw32
GCC target triplet: i686-pc-mingw32


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19309