[Bug preprocessor/51745] New: Strange symbol appears when using commandline definition without "="

[mikulas at artax dot karlin.mff.cuni.cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51745

             Bug #: 51745
           Summary: Strange symbol appears when using commandline
                    definition without "="
    Classification: Unclassified
           Product: gcc
           Version: 4.6.2
            Status: UNCONFIRMED
          Severity: minor
          Priority: P3
         Component: preprocessor
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: mikulas@artax.karlin.mff.cuni.cz
              Host: i686-pc-linux-gnu
            Target: i686-pc-linux-gnu
             Build: i686-pc-linux-gnu


If we use -D definition without "=" in the command line, strange unwanted
symbol "1" appears in the output.

How to reproduce: run gcc -E - -o - "-Dblabla(x, y) bleble[x,y]"
Type blabla(2,3) and press Ctrl-D.
The output is: bleble[2,3] 1
The symbol "1" was never defined anywhere. There is something strange going on
in the commandline parsing. Such syntax without "=" should be either rejected
with an error or it should be processed correctly.