New submission from Takashi Matsuzawa:

I have been debugging for a couple of days to now why my extension module build 
fails with my Yocto 2.0 cross-build environment.
(python version is 2.7, host is x86_64 and target is qemux86).

The symptom is that LD flags -L and -lpython27 are not being passed cross gcc 
and linker fails.
The direct cause of this is that lib/distutils/ not picking up 
Py_ENABLE_SHARED value (it should be 1 since I am linking against shared 

In lib/distutils/, the code is reading the file 
pointer line by line, and only doing string match against #define and #under.
No other type of lines are meaningful to this code.

However, the pyconfig.h I have is like this:

 * Copyright (C) 2005-2011 by Wind River Systems, Inc.

#ifdef _MIPS_SIM
#else /* _MIPS_SIM is not defined */
#include <python2.7/pyconfig-32.h>

So, parse_config_h() fails to get anything from there.
In particular, it fails to get the following in  pyconfig-32.h and I fail to 
build extension module using this configuration of python.

#define Py_ENABLE_SHARED 1

I have looked into the master branch, but the parse_config_h() code is the same 
as what I have on my PC.

I am not sure which of the below is true

1) pyconfig.h should be flat, no #ifdef's, so that parse_config_h() does its 
job sucessfully.
2) parse_config_h() should be flexible to allow ordinal header file syntax 
including #ifdef's and #includes (or pyconfig.h should be preprocessed before 
it is read by parse_config_h()).

components: Cross-Build
messages: 278518
nosy: Alex.Willmer, tmatsuzawa
priority: normal
severity: normal
status: open
title: lib/distutils/ fails to pick up Py_ENABLE_SHARED value
type: compile error
versions: Python 2.7

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