[libvirt] [PATCH] driver: conditionalize use of dlopen functions & use mingw-dlfcn

Daniel P. Berrange berrange at redhat.com
Wed Aug 2 11:53:47 UTC 2017


On Wed, Aug 02, 2017 at 01:31:03PM +0200, Peter Krempa wrote:
> On Wed, Aug 02, 2017 at 11:26:06 +0100, Daniel Berrange wrote:
> > Not every platform is guaranteed to have dlopen/dlsym, so we should
> > conditionalize its use. Suprisingly it is actually present for Win32
> > via the mingw-dlfcn add on, but we should still conditionalize it.
> > 
> > Signed-off-by: Daniel P. Berrange <berrange at redhat.com>
> > ---
> >  configure.ac          |  2 +-
> >  mingw-libvirt.spec.in |  2 ++
> >  src/driver.c          | 18 ++++++++++++++++--
> >  3 files changed, 19 insertions(+), 3 deletions(-)
> > 
> > diff --git a/configure.ac b/configure.ac
> > index b12b7fae1..2b3375138 100644
> > --- a/configure.ac
> > +++ b/configure.ac
> > @@ -328,7 +328,7 @@ dnl Availability of various common headers (non-fatal if missing).
> >  AC_CHECK_HEADERS([pwd.h regex.h sys/un.h \
> >    sys/poll.h syslog.h mntent.h net/ethernet.h linux/magic.h \
> >    sys/un.h sys/syscall.h sys/sysctl.h netinet/tcp.h ifaddrs.h \
> > -  libtasn1.h sys/ucred.h sys/mount.h stdarg.h])
> > +  libtasn1.h sys/ucred.h sys/mount.h stdarg.h dlfcn.h])
> 
> A similar check is done in m4/virt-dlopen.m4:
> 
> AC_CHECK_HEADER([dlfcn.h],, [with_dlfcn=no])
> 
> Is it not enough? We already use HAVE_DLFCN_H in few places.

Oh, I missed that. I'll drop this chunk

> 
> >  dnl Check whether endian provides handy macros.
> >  AC_CHECK_DECLS([htole64], [], [], [[#include <endian.h>]])
> >  AC_CHECK_FUNCS([stat stat64 __xstat __xstat64 lstat lstat64 __lxstat __lxstat64])
> > diff --git a/mingw-libvirt.spec.in b/mingw-libvirt.spec.in
> > index 553d14022..dcb0837f7 100644
> > --- a/mingw-libvirt.spec.in
> > +++ b/mingw-libvirt.spec.in
> > @@ -54,6 +54,8 @@ BuildRequires:  mingw32-libxml2
> >  BuildRequires:  mingw64-libxml2
> >  BuildRequires:  mingw32-portablexdr
> >  BuildRequires:  mingw64-portablexdr
> > +BuildRequires:  mingw32-dlfcn
> > +BuildRequires:  mingw64-dlfcn
> >  
> >  BuildRequires:  pkgconfig
> >  # Need native version for msgfmt
> > diff --git a/src/driver.c b/src/driver.c
> > index 2e7dd01df..04dd0a443 100644
> > --- a/src/driver.c
> > +++ b/src/driver.c
> > @@ -34,10 +34,11 @@ VIR_LOG_INIT("driver");
> >  
> >  
> >  /* XXX re-implement this for other OS, or use libtools helper lib ? */
> > -
> > -#include <dlfcn.h>
> >  #define DEFAULT_DRIVER_DIR LIBDIR "/libvirt/connection-driver"
> >  
> > +#ifdef HAVE_DLFCN_H
> > +# include <dlfcn.h>
> > +
> >  
> >  static void *
> >  virDriverLoadModuleFile(const char *file)
> > @@ -126,6 +127,19 @@ virDriverLoadModuleFull(const char *path,
> >      return ret;
> >  }
> >  
> > +#else /* ! HAVE_DLFCN_H */
> > +int
> > +virDriverLoadModuleFull(const char *path ATTRIBUTE_UNUSED,
> > +                        const char *regfunc ATTRIBUTE_UNUSED,
> > +                        void **handle)
> > +{
> > +    VIR_DEBUG("dlopen not available on this platform");
> > +    if (handle)
> > +        *handle = NULL;
> > +    return -1;
> > +}
> > +#endif /* ! HAVE_DLFCN_H */
> 
> ACK



Regards,
Daniel
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