Re: Building current gdb on centos-5

Pedro Alves
2013-05-30T08:08:40Z

On 05/29/2013 09:50 PM, Julian Smith wrote:

> Is the latest gdb in cvs, expected to build on centos-5 ?

It should, but looks like I broke it.

> I'm seeing this build failure:
>
> ...
> gcc -g -O2 -I. -I. -I./common -I./config -DLOCALEDIR="\"/usr/local/share/locale\"" -DHAVE_CONFIG_H -I./../include/opcode -I./../opcodes/.. -I./../readline/.. -I../bfd -I./../bfd -I./../include -I../libdecnumber -I./../libdecnumber -I./gn
> ulib/import -Ibuild-gnulib/import -DTUI=1 -I/usr/include/python2.4 -I/usr/include/python2.4 -Wall -Wdeclaration-after-statement -Wpointer-arith -Wpointer-sign -Wno-unused -Wunused-value -Wunused-function -Wno-switch -Wno-char-subscripts
> -Wmissing-prototypes -Wdeclaration-after-statement -Wformat-nonliteral -c -o mi-main.o -MT mi-main.o -MMD -MP -MF .deps/mi-main.Tpo ./mi/mi-main.c
> In file included from ./mi/mi-main.c:56:
> ./python/python-internal.h: In function 'gdb_Py_DECREF':
> ./python/python-internal.h:179: warning: dereferencing 'void *' pointer
> ./python/python-internal.h:179: error: request for member 'ob_refcnt' in something not a structure or union

Thanks. gdb_Py_DECREF is a recent addition:

/* Python 2.6 did not wrap Py_DECREF in 'do {...} while (0)', leading
to 'suggest explicit braces to avoid ambiguous Â‘elseÂ’' gcc errors.
Wrap it ourselves, so that callers don't need to care. */

static inline void
gdb_Py_DECREF (void *op) /* ARI: editCase function */
{
Py_DECREF (op);
}

Making that:

- Py_DECREF (op);
+ Py_DECREF ((PyObject*) op);

should fix this. I'll push a fix.

On my system's Python 2.7, Py_DECREF always casts its argument
to (PyObject*), so it didn't seem necessary to cast it ourselves:

#define Py_DECREF(op) \
do { \
if (_Py_DEC_REFTOTAL _Py_REF_DEBUG_COMMA \
--((PyObject*)(op))->ob_refcnt != 0) \
_Py_CHECK_REFCNT(op) \
else \
_Py_Dealloc((PyObject *)(op)); \
} while (0)

> My centos-5 has python-2.4 (python-devel.i386 2.4.3-24.el5).

For the archives, could you please paste what Py_DECREF looks
like in 2.4? Thanks!

--
Pedro Alves