[Qemu-devel] [PATCH] configure: Work around broken static pkg-config info for Ubuntu gnutls

[Qemu-devel] [PATCH] configure: Work around broken static pkg-config info for Ubuntu gnutls

[Peter Maydell]

Unfortunately Ubuntu's pkg-config information for gnutls is broken
for the static linking case, and outputs --libs options which the
compiler does not recognize. Work around this problem by testing
that the --cflags/--libs output will at least allow compilation
before enabling gnutls support.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 configure | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/configure b/configure
index cc0338d..704b34c 100755
--- a/configure
+++ b/configure
@@ -2116,10 +2116,26 @@ fi
 ##########################################
 # GNUTLS probe
 
+gnutls_works() {
+    # Unfortunately some distros have bad pkg-config information for gnutls
+    # such that it claims to exist but you get a compiler error if you try
+    # to use the options returned by --libs. Specifically, Ubuntu for --static
+    # builds doesn't work:
+    # https://bugs.launchpad.net/ubuntu/+source/gnutls26/+bug/1478035
+    #
+    # So sanity check the cflags/libs before assuming gnutls can be used.
+    if ! $pkg_config --exists "gnutls"; then
+        return 1
+    fi
+
+    write_c_skeleton
+    compile_prog "$($pkg_config --cflags gnutls)" "$($pkg_config --libs gnutls)"
+}
+
 gnutls_gcrypt=no
 gnutls_nettle=no
 if test "$gnutls" != "no"; then
-    if $pkg_config --exists "gnutls"; then
+    if gnutls_works; then
         gnutls_cflags=`$pkg_config --cflags gnutls`
         gnutls_libs=`$pkg_config --libs gnutls`
         libs_softmmu="$gnutls_libs $libs_softmmu"
-- 
1.9.1

Re: [Qemu-devel] [PATCH] configure: Work around broken static pkg-config info for Ubuntu gnutls

[Daniel P. Berrange]

On Fri, Jul 24, 2015 at 06:28:08PM +0100, Peter Maydell wrote:
> Unfortunately Ubuntu's pkg-config information for gnutls is broken
> for the static linking case, and outputs --libs options which the
> compiler does not recognize. Work around this problem by testing
> that the --cflags/--libs output will at least allow compilation
> before enabling gnutls support.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Reviewed-by: Daniel P. Berrange <berrange@redhat.com>

Looks like a reasonable approach to me.

> ---
>  configure | 18 +++++++++++++++++-
>  1 file changed, 17 insertions(+), 1 deletion(-)
> 
> diff --git a/configure b/configure
> index cc0338d..704b34c 100755
> --- a/configure
> +++ b/configure
> @@ -2116,10 +2116,26 @@ fi
>  ##########################################
>  # GNUTLS probe
>  
> +gnutls_works() {
> +    # Unfortunately some distros have bad pkg-config information for gnutls
> +    # such that it claims to exist but you get a compiler error if you try
> +    # to use the options returned by --libs. Specifically, Ubuntu for --static
> +    # builds doesn't work:
> +    # https://bugs.launchpad.net/ubuntu/+source/gnutls26/+bug/1478035
> +    #
> +    # So sanity check the cflags/libs before assuming gnutls can be used.
> +    if ! $pkg_config --exists "gnutls"; then
> +        return 1
> +    fi
> +
> +    write_c_skeleton
> +    compile_prog "$($pkg_config --cflags gnutls)" "$($pkg_config --libs gnutls)"
> +}
> +
>  gnutls_gcrypt=no
>  gnutls_nettle=no
>  if test "$gnutls" != "no"; then
> -    if $pkg_config --exists "gnutls"; then
> +    if gnutls_works; then
>          gnutls_cflags=`$pkg_config --cflags gnutls`
>          gnutls_libs=`$pkg_config --libs gnutls`
>          libs_softmmu="$gnutls_libs $libs_softmmu"

Regards,
Daniel
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Re: [Qemu-devel] [PATCH] configure: Work around broken static pkg-config info for Ubuntu gnutls

[Peter Maydell]

On 24 July 2015 at 18:35, Daniel P. Berrange <berrange@redhat.com> wrote:
> On Fri, Jul 24, 2015 at 06:28:08PM +0100, Peter Maydell wrote:
>> Unfortunately Ubuntu's pkg-config information for gnutls is broken
>> for the static linking case, and outputs --libs options which the
>> compiler does not recognize. Work around this problem by testing
>> that the --cflags/--libs output will at least allow compilation
>> before enabling gnutls support.
>>
>> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
>
> Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
>
> Looks like a reasonable approach to me.

Applied to master, thanks.

-- PMM