[Spice-devel] [PATCH 1/2] define SPICE_CONSTRUCTOR_FUNC and SPICE_DESTRUCTOR_FUNC macros

[Frediano Ziglio]

> 
> On Wed, 2016-03-16 at 11:52 -0400, Frediano Ziglio wrote:
> > > 
> > > 
> > > Hi,
> > > 
> > > On Mon, Feb 29, 2016 at 10:36:53AM +0000, Frediano Ziglio wrote:
> > > > 
> > > > Allow to define functions executed at program/shared object
> > > > initialization
> > > > or close.
> > > > 
> > > > Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> > > > ---
> > > >  common/macros.h | 22 ++++++++++++++++++++++
> > > >  1 file changed, 22 insertions(+)
> > > > 
> > > > diff --git a/common/macros.h b/common/macros.h
> > > > index 47289be..fe36929 100644
> > > > --- a/common/macros.h
> > > > +++ b/common/macros.h
> > > > @@ -29,5 +29,27 @@
> > > >  #define SPICE_ATTR_PRINTF
> > > >  #endif /* __GNUC__ */
> > > >  
> > > > +#ifdef __GNUC__
> > > > +#define SPICE_CONSTRUCTOR_FUNC(func_name) \
> > > > +    static void __attribute__((constructor)) func_name(void)
> > > > +#define SPICE_DESTRUCTOR_FUNC(func_name) \
> > > > +    static void __attribute__((destructor)) func_name(void)
> > > > +#elif defined(_MSC_VER)
> > > > +#define SPICE_CONSTRUCTOR_FUNC(func_name) \
> > > > +    static void func_name(void); \
> > > > +    static int func_name ## _wrapper(void) { func_name(); return
> > > > 0; } \
> > > > +    __pragma(section(".CRT$XCU",read)) \
> > > > +    __declspec(allocate(".CRT$XCU")) static int (* _array ##
> > > > func_name)(void) = func_name ## _wrapper; \
> > > > +    static void func_name(void)
> > > > +#define SPICE_DESTRUCTOR_FUNC(func_name) \
> > > > +    static void func_name(void); \
> > > > +    static int func_name ## _wrapper(void) { func_name(); return
> > > > 0; } \
> > > > +    __pragma(section(".CRT$XPU",read)) \
> > > > +    __declspec(allocate(".CRT$XPU")) static int (* _array ##
> > > > func_name)(void) = func_name ## _wrapper; \
> > > > +    static void func_name(void)
> > > > +#else
> > > > +#error Please implement SPICE_CONSTRUCTOR_FUNC and
> > > > SPICE_DESTRUCTOR_FUNC
> > > > for this compiler
> > > > +#endif
> > > > +
> > > >  
> > > >  #endif /* __MACROS_H */
> > > > --
> > > > 2.5.0
> > > Testes, works without issues.
> > > 
> > > I'm wondering why not to include the whole header from glib [0] and
> > > maybe file a bug to ask them to export in the future.
> > > 
> > > [0] https://git.gnome.org/browse/glib/tree/glib/gconstructor.h
> > > 
> > > Then, in case G_HAS_CONSTRUCTORS is not defined we can include
> > > different
> > > arch constructors. What do you think?
> > > 
> > > PS: while looking for an open bug:
> > > aix: https://bugzilla.gnome.org/show_bug.cgi?id=763560
> > > hp-ux/ia: https://bugzilla.gnome.org/show_bug.cgi?id=763466
> > > 
> > > cheers,
> > >   toso
> > > 
> > Do we want to support HP-UX or AIX? I did work on HP-UX and from what
> > I
> > can see not even HP is supporting that much this OS.
> > Personally I don't like Gnome implementation, particularly the atexit
> > call
> > on Windows.
> > I don't understand the g_slist_find call either.
> > 
> > Frediano
> 
> 
> What about clang ? Does it work there?
> 
> Pavel

Yes, these attributes are supported. clang defines __GNUC__ so this works.

Frediano