Re: [Qemu-devel] [PATCH] configure: Add a proper check for openpty() in libutil

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 1/17/19 6:14 PM, Thomas Huth wrote:
> On Linux (and maybe some BSDs), we require libutil for the openpty()
> function. However, this library is not available on some other systems, so
> we currently use a fragile if-statement in the configure script to check
> whether we need the library or not. Unfortunately, we also hard-coded a
> "-lutil" in the tests/Makefile.include file, so this breaks the build on
> Solaris, for example (see buglink below). To fix the issue, add the "-lutil"
> to "libs_tools" in the configure script instead, then this gets properly
> propagated to the tests, too.
> And while we're at it, also replace the fragile if-statement in the confi-
> gure script with a proper link-check for the availablity of this function.

Clean.

> 
> Buglink: https://bugs.launchpad.net/qemu/+bug/1777252
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>  configure              | 12 ++++++++++--
>  tests/Makefile.include |  4 ----
>  2 files changed, 10 insertions(+), 6 deletions(-)
> 
> diff --git a/configure b/configure
> index 3c28bae..0f4e42a 100755
> --- a/configure
> +++ b/configure
> @@ -4595,9 +4595,17 @@ elif compile_prog "" "$pthread_lib -lrt" ; then
>    libs_qga="$libs_qga -lrt"
>  fi
>  
> -if test "$darwin" != "yes" -a "$mingw32" != "yes" -a "$solaris" != yes -a \
> -        "$haiku" != "yes" ; then
> +# Check whether we need to link libutil for openpty()
> +cat > $TMPC << EOF
> +extern int openpty(int *am, int *as, char *name, void *termp, void *winp);
> +int main(void) { return openpty(0, 0, 0, 0, 0); }
> +EOF
> +
> +if ! compile_prog "" "" ; then
> +  if compile_prog "" "-lutil" ; then
>      libs_softmmu="-lutil $libs_softmmu"
> +    libs_tools="-lutil $libs_tools"

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> +  fi
>  fi
>  
>  ##########################################
> diff --git a/tests/Makefile.include b/tests/Makefile.include
> index f403a65..8f8e3b4 100644
> --- a/tests/Makefile.include
> +++ b/tests/Makefile.include
> @@ -793,10 +793,6 @@ tests/migration/initrd-stress.img: tests/migration/stress$(EXESUF)
>  	rm $(INITRD_WORK_DIR)/init
>  	rmdir $(INITRD_WORK_DIR)
>  
> -ifeq ($(CONFIG_POSIX),y)
> -LIBS += -lutil
> -endif
> -
>  # QTest rules
>  
>  TARGETS=$(patsubst %-softmmu,%, $(filter %-softmmu,$(TARGET_DIRS)))
>