[Python-Dev] Strange compiler crash in debug builds. (original) (raw)

Thomas Wouters thomas@xs4all.net
Fri, 25 Aug 2000 07:29:53 +0200

On Fri, Aug 25, 2000 at 03:16:56PM +1000, Mark Hammond wrote:

Something strange is happening in my Windows Debug builds (fresh CVS tree)

If you remove "urllib.pyc", and execute 'pythond -c "import urllib"', Python dies after printing the message:

FATAL: node type 305, required 311 It also happens for a number of other files (compileall.py will show you :-)

Further analysis shows this deep in the compiler, and triggered by this macro in node.h:

_#define REQ(n, type) _ _{ if (TYPE(n) != (type)) { _ _fprintf(stderr, "FATAL: node type %d, required %d\n", _ _TYPE(n), type); _ _abort(); _ } }

Is this pointing to a deeper problem, or is the assertion incorrect?

At first sight, I would say "yes, the assertion is wrong". That doesn't mean it shouldn't be fixed ! It's probably caused by augmented assignment or list comprehensions, though I have used both with Py_DEBUG enabled a few times, so I don't know for sure. I'm compiling with debug right now, to inspect this, though.

Another thing that might cause it is an out-of-date graminit.h file somewhere. The one in the CVS tree is up to date, but maybe you have a copy stashed somewhere ?

Does the Linux community ever run with PyDEBUG defined? I couldn't even find a simple way to turn it on to confirm it also exists on Linux...

There's undoubtedly a good way, but I usually just chicken out and add '#define Py_DEBUG 1' at the bottom of config.h ;) That also makes sure I don't keep it around too long, as config.h gets regenerated often enough :)

-- Thomas Wouters <thomas@xs4all.net>

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