Missing function "yyerror"

[Wolfgang Jansen]

Hello,

I'm using bison for the first time. After composing a grammar
the generated C file compiles but linking fails because of:

parser.tab.c:2778: undefined reference to `yyerror'
parser.tab.c:2920: undefined reference to `yyerror'

So what can I do to get the missing function?
Is a library to be linked? (The man-pages do not mention one,
and I do not see one in the common "lib" directories.)
Also the scanner (not in the attachment) does not provide one.

I'm using version "bison (GNU Bison) 2.5" downloaded and
installed a few days ago on Linux Ubuntu; bison command was:

bison --defines parser.y


Best regards
Wolfgang

PS:
The attachment contains the .y file in question and some related files.
C compilation is done by a command like
gcc -g -c parser.tab.c `pkg-config --libs --cflags gtk+-2.0`

--
Dr. Wolfgang Jansen
Lauenburger Straße 40
12169 Berlin
Germany
Tel: +49 - 0172-4086916
mailto: address@hidden

expr.c
Description: Text Data

expr.h
Description: Text Data

parser.y
Description: Text document

test.c
Description: Text Data