gcc 4.6 bug has been fixed (http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47271). So setup.py can compile extensions using gcc 4.6, and here are new warnings:
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building dbm using bdb
/home/haypo/prog/GIT/py3k/Modules/_pickle.c: In function 'load':
/home/haypo/prog/GIT/py3k/Modules/_pickle.c:5267:9: warning: case value '0' not in enumerated type 'enum opcode' [-Wswitch]
/home/haypo/prog/GIT/py3k/Modules/_csv.c: In function 'parse_grow_buff':
/home/haypo/prog/GIT/py3k/Modules/_csv.c:537:21: warning: operation on 'self->field' may be undefined [-Wsequence-point]
/home/haypo/prog/GIT/py3k/Modules/_csv.c: In function 'join_check_rec_size':
/home/haypo/prog/GIT/py3k/Modules/_csv.c:1058:23: warning: operation on 'self->rec' may be undefined [-Wsequence-point]
/home/haypo/prog/GIT/py3k/Modules/_posixsubprocess.c:4:0: warning: "_GNU_SOURCE" redefined [enabled by default]
./pyconfig.h:1151:0: note: this is the location of the previous definition
/home/haypo/prog/GIT/py3k/Modules/socketmodule.c: In function 'socket_gethostbyname_ex':
/home/haypo/prog/GIT/py3k/Modules/socketmodule.c:3318:9: warning: variable 'result' set but not used [-Wunused-but-set-variable]
/home/haypo/prog/GIT/py3k/Modules/socketmodule.c: In function 'socket_gethostbyaddr':
/home/haypo/prog/GIT/py3k/Modules/socketmodule.c:3396:9: warning: variable 'result' set but not used [-Wunused-but-set-variable]
/home/haypo/prog/GIT/py3k/Modules/_sqlite/connection.c: In function '_pysqlite_final_callback':
/home/haypo/prog/GIT/py3k/Modules/_sqlite/connection.c:676:15: warning: variable 'aggregate_class' set but not used [-Wunused-but-set-variable]
/home/haypo/prog/GIT/py3k/Modules/_sqlite/cursor.c: In function 'pysqlite_cursor_dealloc':
/home/haypo/prog/GIT/py3k/Modules/_sqlite/cursor.c:129:9: warning: variable 'rc' set but not used [-Wunused-but-set-variable]
/home/haypo/prog/GIT/py3k/Modules/_sqlite/statement.c: In function 'pysqlite_statement_dealloc':
/home/haypo/prog/GIT/py3k/Modules/_sqlite/statement.c:372:9: warning: variable 'rc' set but not used [-Wunused-but-set-variable]
/home/haypo/prog/GIT/py3k/Modules/_tkinter.c: In function 'PythonCmd':
/home/haypo/prog/GIT/py3k/Modules/_tkinter.c:2008:15: warning: variable 'self' set but not used [-Wunused-but-set-variable]
/home/haypo/prog/GIT/py3k/Modules/tkappinit.c: In function 'Tcl_AppInit':
/home/haypo/prog/GIT/py3k/Modules/tkappinit.c:29:15: warning: variable 'main_window' set but not used [-Wunused-but-set-variable]
(...)
/home/haypo/prog/GIT/py3k/Modules/_ctypes/cfield.c: In function 'PyCField_FromDesc':
/home/haypo/prog/GIT/py3k/Modules/_ctypes/cfield.c:55:29: warning: variable 'length' set but not used [-Wunused-but-set-variable]
/home/haypo/prog/GIT/py3k/Modules/_ctypes/libffi/src/dlmalloc.c: In function 'mmap_resize':
/home/haypo/prog/GIT/py3k/Modules/_ctypes/libffi/src/dlmalloc.c:3193:5: warning: implicit declaration of function 'mremap' [-Wimplicit-function-declaration]
/home/haypo/prog/GIT/py3k/Modules/_ctypes/libffi/src/dlmalloc.c:3193:16: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
/home/haypo/prog/GIT/py3k/Modules/_ctypes/libffi/src/dlmalloc.c: In function 'sys_trim':
/home/haypo/prog/GIT/py3k/Modules/_ctypes/libffi/src/dlmalloc.c:3612:62: warning: comparison between pointer and integer [enabled by default]
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