Build Qt for OS X and iOS with relative rpath.

Defaulting to absolute_library_soname on configure -rpath is no longer
necessary as now we support @rpath install name ids on OS X and iOS.

This also sets QMAKE_SONAME_PREFIX to @rpath for Qt modules when built
with rpath configuration.

This makes Qt libraries relocatable on OS X. Qt SDK is not yet
relocatable though, because plugin locations (including cocoa plugin)
are still resolved using absolute path (see QTBUG-14150). Also, there
are several absolute paths hardcoded in qmake mkspecs pri files.

Task-number: QTBUG-31814
Change-Id: I36b9384cd69ac609608acbe2b3d5e0512317e0d6
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@theqtcompany.com>

configure

@@ -6205,11 +6205,7 @@ fi
 [ '!' -z "$INCLUDES" ] && QMakeVar add INCLUDEPATH "$INCLUDES"
 [ '!' -z "$L_FLAGS" ] && QMakeVar add LIBS "$L_FLAGS"
 
-if [ "$XPLATFORM_MAC" = "yes" ] && [ "$QT_CROSS_COMPILE" = "no" ]; then
-    if [ "$CFG_RPATH" = "yes" ]; then
-       QMAKE_CONFIG="$QMAKE_CONFIG absolute_library_soname"
-    fi
-elif [ -z "`getXQMakeConf 'QMAKE_(LFLAGS_)?RPATH'`" ]; then
+if [ -z "`getXQMakeConf 'QMAKE_(LFLAGS_)?RPATH'`" ]; then
     if [ -n "$RPATH_FLAGS" ]; then
         echo
         echo "ERROR: -R cannot be used on this platform as \$QMAKE_LFLAGS_RPATH is"

mkspecs/features/qt_build_config.prf

@@ -52,12 +52,6 @@ QMAKE_DIR_REPLACE_SANE = PRECOMPILED_DIR OBJECTS_DIR MOC_DIR RCC_DIR UI_DIR
     unset(modpath)
 }
 
-mac {
-   !isEmpty(QMAKE_RPATHDIR){
-       CONFIG += absolute_library_soname
-   }
-}
-
 cross_compile: \
     CONFIG += force_bootstrap
 

mkspecs/features/qt_module.prf

@@ -132,6 +132,9 @@ mac {
        QMAKE_CFLAGS += -fconstant-cfstrings
        QMAKE_CXXFLAGS += -fconstant-cfstrings
    }
+
+   contains(QT_CONFIG, rpath): \
+       QMAKE_SONAME_PREFIX = @rpath
 }
 
 DEFINES += QT_BUILDING_QT