C & Java examples fail to run

[AlexPoupakis]

The examples are built without issue, but running them raises multiple warnings and errors. The message starts with

/tmp/pybison/pybison_Parser/tmp.y:9:1: warning: ‘dllexport’ attribute directive ignored [-Wattributes]
 __attribute__ ((dllexport)) char *rules_hash = "e75e4fff863f00275cca52cdad5000500054ed4d";
 ^~~~~~~~~~~~~
/tmp/pybison/pybison_Parser/tmp.y: In function ‘yyparse’:
/tmp/pybison/pybison_Parser/tmp.y:58:19: warning: assignment makes integer from pointer without a cast [-Wint-conversion]
           $$ = (*py_callback)(

followed by many assignment from int without cast warnings and ends with

tmp.tab.c:6024:18: warning: passing argument 1 of ‘yyerror’ discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
In file included from /tmp/pybison/pybison_Parser/tmp.y:3:0:
/tmp/pybison/pybison_Parser/tmp.y:27:5: note: expected ‘char *’ but argument is of type ‘const char *’
 int yyerror(char *msg);
     ^~~~~~~
/tmp/pybison/pybison_Parser/tmp.y: At top level:
/tmp/pybison/pybison_Parser/tmp.y:3444:1: warning: ‘dllexport’ attribute directive ignored [-Wattributes]
 {
 ^
/tmp/pybison/pybison_Parser/tmp.l:20:10: fatal error: tokens.h: No such file or directory
 #include "tokens.h"
          ^~~~~~~~~~
compilation terminated.
Traceback (most recent call last):
  File "/usr/lib/python3.6/distutils/unixccompiler.py", line 118, in _compile
    extra_postargs)
  File "/usr/lib/python3.6/distutils/ccompiler.py", line 909, in spawn
    spawn(cmd, dry_run=self.dry_run)
  File "/usr/lib/python3.6/distutils/spawn.py", line 36, in spawn
    _spawn_posix(cmd, search_path, dry_run=dry_run)
  File "/usr/lib/python3.6/distutils/spawn.py", line 159, in _spawn_posix
    % (cmd, exit_status))
distutils.errors.DistutilsExecError: command 'cc' failed with exit status 1

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "c.py", line 1162, in <module>
    main(*(sys.argv[1:]))
  File "c.py", line 1157, in main
    p = Parser(verbose=verbose, keepfiles=keepfiles)
  File "/home/alex/.local/lib/python3.6/site-packages/bison/__init__.py", line 224, in __init__
    self.engine = ParserEngine(self)
  File "src/bison/cython/bison_.pyx", line 135, in bison.bison_.ParserEngine.__init__
  File "src/bison/cython/bison_.pyx", line 172, in bison.bison_.ParserEngine.openCurrentLib
  File "src/bison/cython/bison_.pyx", line 691, in bison.bison_.ParserEngine.buildLib
  File "/usr/lib/python3.6/distutils/ccompiler.py", line 574, in compile
    self._compile(obj, src, ext, cc_args, extra_postargs, pp_opts)
  File "/usr/lib/python3.6/distutils/unixccompiler.py", line 120, in _compile
    raise CompileError(msg)
distutils.errors.CompileError: command 'cc' failed with exit status 1

I get the same message for both C and Java examples. The issue is similar to #19 and was supposedly fixed in the latest version.

OS: Ubuntu 18.04.5 (also tested on CentOS 7 & 8)

Tool versions: flex 2.6.4 (latest), bison 3.0.4 (latest), pybison 0.2.9 (latest)

[sbrodehl]

Hey @AlexPoupakis, thanks for reaching out!

I fixed the error: tokens.h: No such file or directory, this will get the example parser compile again.

But, the examples are a little bit out of date, so they are currently not running.

I added a short introduction in the README.md on debugging, so that you can better debug the parser you are creating.

[AlexPoupakis]

Thanks @sbrodehl. I updated pybison (even uninstalling and re-installing it) but still get the error: tokens.h: No such file or directory...

[sbrodehl]

Have you used the updated example files as well? Which example do you use?

[AlexPoupakis]

Ahh sorry, I was using the old ones for C. Something else I noticed is that in the python script, you are calling main with a tuple and then calling args.remove(). Since args contains just a tuple, remove will cause an error because tuples are immutable.

[yh0508619]

@sbrodehl I am also unable to run the examples for C and Java as well, I got the error
self.engine.runEngine(debug)
NameError: name 'debug' is not defined

I am using ubuntu 18.04, and I have python 3.6.9 installed

[sbrodehl]

Hi @yh0508619,
the variable debugshould be defined 🤔
What version are you using? Maybe try the latest release?

On a general note, the examples and tests are very outdated and do not work with current flex/bison versions!

[yh0508619]

@sbrodehl Thanks for your rapid response
I am using the latest version on the github.
The versions for bison and flex are:
bison (GNU Bison) 3.0.4
flex 2.6.4

[yh0508619]

Hi @sbrodehl

Sorry to bother you again, which python version you are using ? I installed python 3.9, but error becomes:
ImportError: cannot import name 'BisonParser' from 'bison'

Thanks!

[sbrodehl]

Have you installed the pybison package? Make sure to build the shared libraries, e.g. using python setup.py build.

[yh0508619]

Have you installed the pybison package? Make sure to build the shared libraries, e.g. using python setup.py build.

Yeah, bison, flex and pybison are installed

[sbrodehl]

Sorry, I can not reproduce this.
Maybe submit a detailed report as a separate issue?