[Cython] Compiler crash in RemoveUnreachableCode

[Stefan Behnel]

Hi,

thanks for the report, I can reproduce this.

Andriy Kornatskyy, 19.01.2014 21:00:
> The cython compiler crash report below. Steps to reproduce:
> 
> 1. virtualenv env
> 2. env/bin/easy_install cython
> 3. env/bin/easy_install wheezy.http
>
> The wheezy.http has dependency on wheezy.core. If I install those two packages separately there is no error, only if through dependencies.

Yes, that's rather surprising.


>   File "Visitor.py", line 178, in Cython.Compiler.Visitor.TreeVisitor._visit (/var/folders/g8/2kym1h8n7qbgrwg4qkfqw1gw0000gn/T/easy_install-JVXbGE/Cython-0.20/Cython/Compiler/Visitor.c:4437)
>   File "Visitor.py", line 137, in Cython.Compiler.Visitor.TreeVisitor._raise_compiler_error (/var/folders/g8/2kym1h8n7qbgrwg4qkfqw1gw0000gn/T/easy_install-JVXbGE/Cython-0.20/Cython/Compiler/Visitor.c:3655)
> Cython.Compiler.Errors.CompilerCrash:
> Error compiling Cython file:
> ------------------------------------------------------------
> ...
> 
> """
> """
> 
> __version__ = '0.1.129'
>              ^
> ------------------------------------------------------------
> 
> src/wheezy/core/__init__.py:5:14: Compiler crash in RemoveUnreachableCode
> 
> ModuleNode.body = StatListNode(__init__.py:5:14)
> 
> Compiler crash traceback from this point on:
>   File "Visitor.py", line 170, in Cython.Compiler.Visitor.TreeVisitor._visit (/var/folders/g8/2kym1h8n7qbgrwg4qkfqw1gw0000gn/T/easy_install-JVXbGE/Cython-0.20/Cython/Compiler/Visitor.c:4275)
>   File “/.../env/lib/python2.7/site-packages/Cython-0.20-py2.7-macosx-10.9-x86_64.egg/Cython/Compiler/ParseTreeTransforms.py", line 2135, in visit_StatListNode
>     if not self.current_directives['remove_unreachable']:
> TypeError: 'NoneType' object has no attribute '__getitem__'

I only get this when Cython is compiled. When I run it from the source
tree, it works.

Debugging into Visitor.py's CythonTransform shows that this check fails:

        if isinstance(node, ModuleNode.ModuleNode):
            self.current_directives = node.directives

"node" actually *is* an instance of ModuleNode, just not of *that* ModuleNode.

My guess is that there's something wrong with the import mechanism that
leads to the module being imported twice. Relative versus absolute imports,
most likely. I also see a couple of weird modules in sys.modules, e.g.
"Cython.Compiler.re", so there are some more bits going generally wrong here.

I also tried it in Py3, but that even gives me a hard crash. Not really better.

I might be able to take a deeper look this weekend, but wouldn't mind if
others beat me to it.

Stefan