cython 0.9.6.13.1 fails with gcc 2.95.2 (compiling lxml)

[Holger Joukl]

Trying to compile the latest lxml trunk with Cython 0.9.6.13.1 fails with gcc 2.95.2
(Support for older compilers has been temporarily lost before, e.g. #137002):

python2.4 setup.py build
Building lxml version 2.1.alpha1-53648.
Building with Cython 0.9.6.13.1.
Using build configuration of libxslt 1.1.20
Building against libxml2/libxslt in one of the following directories:
  /apps/prod//lib
  /data/pydev/DOWNLOADS/LXML/libxml2/libxml2-2.6.27
running build
running build_py
writing byte-compilation script '/tmp/tmpAQK0Ye.py'
/apps/pydev/bin/python2.4 -O /tmp/tmpAQK0Ye.py
removing /tmp/tmpAQK0Ye.py
running build_ext
building 'lxml.etree' extension
gcc -fno-strict-aliasing -DNDEBUG -g -O3 -Wall -Wstrict-prototypes -fPIC -I/apps/prod//include -I/apps/prod//include/libxml2 -I/apps/prod/include/libxml2 -I/apps/prod/include -I/apps/pydev/include/python2.4 -c src/lxml/lxml.etree.c -o build/temp.solaris-2.8-sun4u-2.4/src/lxml/lxml.etree.o -w
src/lxml/lxml.etree.c: In function `init2etree':
src/lxml/lxml.etree.c:112054: parse error before `*'
src/lxml/lxml.etree.c:112085: `__pyx_1' undeclared (first use in this function)
src/lxml/lxml.etree.c:112085: (Each undeclared identifier is reported only once
src/lxml/lxml.etree.c:112085: for each function it appears in.)
src/lxml/lxml.etree.c:112106: `__pyx_2' undeclared (first use in this function)
src/lxml/lxml.etree.c:112124: `__pyx_3' undeclared (first use in this function)
src/lxml/lxml.etree.c:112127: `__pyx_4' undeclared (first use in this function)
src/lxml/lxml.etree.c:112136: `__pyx_5' undeclared (first use in this function)
src/lxml/lxml.etree.c:112139: `__pyx_6' undeclared (first use in this function)
src/lxml/lxml.etree.c:112343: `__pyx_7' undeclared (first use in this function)
src/lxml/lxml.etree.c:113493: `__pyx_8' undeclared (first use in this function)
src/lxml/lxml.etree.c:113565: `__pyx_9' undeclared (first use in this function)
src/lxml/lxml.etree.c:113574: `__pyx_10' undeclared (first use in this function)
src/lxml/lxml.etree.c:113575: `__pyx_11' undeclared (first use in this function)
src/lxml/lxml.etree.c:113662: `__pyx_12' undeclared (first use in this function)
src/lxml/lxml.etree.c:113663: `__pyx_13' undeclared (first use in this function)
error: command 'gcc' failed with exit status 1

I'd say this is due to variables being declared not _only_ at the start of the function,
which old (gcc) compilers are pretty anal about:

 112049 PyMODINIT_FUNC init2etree(void); /*proto*/
 112050 PyMODINIT_FUNC init2etree(void) {
 112051 static int __Pyx_unique = 0;
 112052 if (__Pyx_unique==1) return;
 112053 __Pyx_unique = 1;
 112054 PyObject *__pyx_1 = 0;
 112055 PyObject *__pyx_2 = 0;
 112056 int __pyx_3;

Holger

[Holger Joukl (jholg)]

While I *think* this should be a trivial fix for the problem:

diff -r e005b58d83b8 Cython/Compiler/ModuleNode.py
--- a/Cython/Compiler/ModuleNode.py Tue Apr 08 01:25:09 2008 -0700
+++ b/Cython/Compiler/ModuleNode.py Tue Apr 15 14:22:51 2008 +0200
@@ -1443,10 +1443,10 @@ class ModuleNode(Nodes.Node, Nodes.Block
         header = "PyMODINIT_FUNC init2%s(void)" % env.module_name
         code.putln("%s; /*proto*/" % header)
         code.putln("%s {" % header)
+ code.put_var_declarations(env.temp_entries)
         code.putln("static int __Pyx_unique = 0;")
         code.putln("if (__Pyx_unique==1) return;")
         code.putln("__Pyx_unique = 1;")
- code.put_var_declarations(env.temp_entries)
         code.putln("/*--- Execution code ---*/")
         code.mark_pos(None)
         self.body.generate_execution_code(code)

... I currently cannot test this, as I then run into other lxml compilation problems, see below.
However, I see these other problems also with gcc 4.2.1, so they don't seem related
to the compiler version, but rather be either an lxml-specific or a more general cython
problem.

gcc -fno-strict-aliasing -DNDEBUG -g -O3 -Wall -Wstrict-prototypes -fPIC -I/apps/prod//include -I/apps/prod//include/libxml2 -I/apps/prod/include/libxml2 -I/apps/prod/include -I/apps/pydev/include/python2.4 -c src/lxml/lxml.objectify.c -o build/temp.solaris-2.8-sun4u-2.4/src/lxml/lxml.objectify.o -w
In file included from src/lxml/lxml.objectify.c:52:
src/lxml/lxml.etree_api.h: In function `import_lxml__etree':
src/lxml/lxml.etree_api.h:219: sizeof applied to an incomplete type
src/lxml/lxml.etree_api.h:220: sizeof applied to an incomplete type
src/lxml/lxml.etree_api.h:221: sizeof applied to an incomplete type
src/lxml/lxml.etree_api.h:222: sizeof applied to an incomplete type
src/lxml/lxml.etree_api.h:223: sizeof applied to an incomplete type
src/lxml/lxml.etree_api.h:224: sizeof applied to an incomplete type
src/lxml/lxml.etree_api.h:225: sizeof applied to an incomplete type
src/lxml/lxml.etree_api.h:226: sizeof applied to an incomplete type
src/lxml/lxml.objectify.c: At top level:
src/lxml/lxml.objectify.c:248: field `__pyx_base' has incomplete type
src/lxml/lxml.objectify.c:260: field `__pyx_base' has incomplete type
src/lxml/lxml.objectify.c:274: field `__pyx_base' has incomplete type
src/lxml/lxml.objectify.c:286: field `__pyx_base' has incomplete type
src/lxml/lxml.objectify.c:310: field `__pyx_base' has incomplete type
src/lxml/lxml.objectify.c:322: field `__pyx_base' has incomplete type
src/lxml/lxml.objectify.c:334: field `__pyx_base' has incomplete type
src/lxml/lxml.objectify.c: In function `__pyx_pf_4lxml_9objectify_18ObjectifiedElement_8__dict_____get__':
src/lxml/lxml.objectify.c:1150: dereferencing pointer to incomplete type
src/lxml/lxml.objectify.c:1150: dereferencing pointer to incomplete type
src/lxml/lxml.objectify.c:1165: dereferencing pointer to incomplete type
src/lxml/lxml.objectify.c:1216: dereferencing pointer to incomplete type
src/lxml/lxml.objectify.c: In function `__pyx_pf_4lxml_9objectify_18ObjectifiedElement___setattr__':
src/lxml/lxml.objectify.c:1714: dereferencing pointer to incomplete type
src/lx...

[scoder (scoder)]

Ah, sorry this has been fixed by reverting the patch that introduced this (and a couple of other) problems. Try 0.9.6.12 for now, or the latest developer version of Cython.

http://hg.cython.org/cython-devel/