build,qt: Support building Qt bindings as nested package of gpgme

* autogen-all.sh (packages): Add lang/qt.
* configure.ac: Add qt to available languages if subdir exists. Add
qt to nested languages if enabled to generate corresponding make
targets. Call configure script of nested qt package recursively.
* lang/qt/configure.ac: Check if qgpgme is built as nested package
and set GPGME_CFLAGS, GPGME_LIBS, GPGMEPP_CFLAGS, and GPGMEPP_LIBS
accordingly.
--

This re-adds the ability to build the Qt bindings together with gpgme
with a single `configure && make` command (if building from git).

GnuPG-bug-id: 7110

autogen-all.sh

@@ -15,7 +15,7 @@
 
 prog=$(basename "$0")
 
-packages=". lang/cpp"
+packages=". lang/cpp lang/qt"
 
 fatal () {
     echo "${prog}:" "$*" >&2

configure.ac

@@ -238,7 +238,7 @@ have_macos_system=no
 build_w32_glib=no
 available_languages="cl"
 default_languages="cl"
-for lang in cpp; do
+for lang in cpp qt; do
   if test -d $srcdir/lang/$lang; then
     available_languages="$available_languages $lang"
   fi
@@ -360,6 +360,10 @@ LIST_MEMBER("cpp", $enabled_languages)
 if test "$found" = "1"; then
   nested_languages="$nested_languages cpp"
 fi
+LIST_MEMBER("qt", $enabled_languages)
+if test "$found" = "1"; then
+  nested_languages="$nested_languages qt"
+fi
 
 AC_SUBST(NESTED_LANGUAGES, $nested_languages)
 
@@ -843,6 +847,10 @@ LIST_MEMBER("cpp", $enabled_languages)
 if test "$found" = "1"; then
   AC_CONFIG_SUBDIRS([lang/cpp])
 fi
+LIST_MEMBER("qt", $enabled_languages)
+if test "$found" = "1"; then
+  AC_CONFIG_SUBDIRS([lang/qt])
+fi
 
 AC_OUTPUT
 

lang/qt/configure.ac

@@ -469,16 +469,43 @@ AC_DEFINE(GPG_ERR_SOURCE_DEFAULT, GPG_ERR_SOURCE_GPGME,
 AM_CONDITIONAL(USE_GPGRT_CONFIG, [test -n "$GPGRT_CONFIG" \
                                   -a "$ac_cv_path_GPG_ERROR_CONFIG" = no])
 
-# And for gpgme.
+# Check for gpgme and gpgmepp.
 have_gpgme=no
+have_gpgmepp=no
+# Check if qgpgme is built as nested package of gpgme
+builddir=`pwd`
+if test "${srcdir%/lang/qt}/lang/qt" == "$srcdir" -a \
+        "${builddir%/lang/qt}/lang/qt" == "$builddir"; then
+  AC_MSG_CHECKING(for GpgME - assuming nested build)
+  gpgme_build_dir=${builddir%/lang/qt}
+  if test -f "$gpgme_build_dir/src/gpgme.h"; then
+    GPGME_CFLAGS="-I$gpgme_build_dir/src"
+    GPGME_LIBS="$gpgme_build_dir/src/libgpgme.la"
+    have_gpgme=yes
+    AC_MSG_RESULT(yes)
+  else
+    AC_MSG_RESULT(no)
+  fi
+  AC_MSG_CHECKING(for GpgME++ - assuming nested build)
+  gpgmepp_build_dir=${builddir%/lang/qt}/lang/cpp
+  if test -f "$gpgmepp_build_dir/src/gpgmepp_version.h"; then
+    GPGMEPP_CFLAGS="-I$gpgmepp_build_dir/src"
+    GPGMEPP_LIBS="$gpgmepp_build_dir/src/libgpgmepp.la"
+    have_gpgmepp=yes
+    AC_MSG_RESULT(yes)
+  else
+    AC_MSG_RESULT(no)
+  fi
+fi
+
+if test "$have_gpgme" = "no"; then
   AM_PATH_GPGME("$NEED_GPGME_VERSION",
                 have_gpgme=yes, have_gpgme=no)
-
-# And for gpgmepp.
-have_gpgmepp=no
+fi
+if test "$have_gpgmepp" = "no"; then
   AM_PATH_GPGMEPP("$NEED_GPGMEPP_VERSION",
                   have_gpgmepp=yes, have_gpgmepp=no)
-
+fi
 
 # Last check.
 die=no