Merge #13458: gui: Drop qt4 support

af6ac3b677454644364fd24d0df0c02ac9b8c8db doc: Remove mention of Qt4 from build docs (Wladimir J. van der Laan)
462c71f71b5d753bc8327ab833dea23679450ca3 test: Update travis to not test Qt4 anymore (Wladimir J. van der Laan)
907f73bbc5b6c98b01d7c6088a294dea66634a3f gui: Remove QT_VERSION fallbacks for Qt < 5 (Wladimir J. van der Laan)
bad068ad9f4bc60bfc10e27d4ffaec92d7df8491 build: Build system changes to support only Qt5 (Wladimir J. van der Laan)

Pull request description:

  Implements #8263.

  Qt4.x has been EOL since 2015, and at least Gentoo has, or is going to drop support for it. I wouldn't be surprised if other Linux distributions follow.

  This removes Qt4 detection from the build system, as well as removes all Qt4 fallbacks from the code. Turns out there's more than I expected: this is going to make maintenance of the GUI code, as well as adding new features significantly easier.

  (I know there's still some references left to qt4 in RPM and Debian build script, but I don't have the knowledge how to fix them)

Tree-SHA512: d495924fd4dda6f6566ba44ee96be7cbe62e69ba1ca993b80a8449f78da852b7f1bd3e8200d57cfa1d72233c340eeff4596fb0032ecbddc715d99aea63817d3f

1 files changed, 90 insertions, 147 deletions

diff --git a/build-aux/m4/bitcoin_qt.m4 b/build-aux/m4/bitcoin_qt.m4
index f41508336c..fe0cc6c36d 100644
--- a/build-aux/m4/bitcoin_qt.m4
+++ b/build-aux/m4/bitcoin_qt.m4
@@ -53,8 +53,8 @@ dnl CAUTION: Do not use this inside of a conditional.
 AC_DEFUN([BITCOIN_QT_INIT],[
   dnl enable qt support
   AC_ARG_WITH([gui],
-    [AS_HELP_STRING([--with-gui@<:@=no|qt4|qt5|auto@:>@],
-    [build bitcoin-qt GUI (default=auto, qt5 tried first)])],
+    [AS_HELP_STRING([--with-gui@<:@=no|qt5|auto@:>@],
+    [build bitcoin-qt GUI (default=auto)])],
     [
      bitcoin_qt_want_version=$withval
      if test "x$bitcoin_qt_want_version" = xyes; then
@@ -94,18 +94,17 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
   fi
 
   if test "x$use_pkgconfig" = xyes; then
-    BITCOIN_QT_CHECK([_BITCOIN_QT_FIND_LIBS_WITH_PKGCONFIG([$2])])
+    BITCOIN_QT_CHECK([_BITCOIN_QT_FIND_LIBS_WITH_PKGCONFIG])
   else
     BITCOIN_QT_CHECK([_BITCOIN_QT_FIND_LIBS_WITHOUT_PKGCONFIG])
   fi
 
   dnl This is ugly and complicated. Yuck. Works as follows:
-  dnl We can't discern whether Qt4 builds are static or not. For Qt5, we can
-  dnl check a header to find out. When Qt is built statically, some plugins must
-  dnl be linked into the final binary as well. These plugins have changed between
-  dnl Qt4 and Qt5. With Qt5, languages moved into core and the WindowsIntegration
-  dnl plugin was added. Since we can't tell if Qt4 is static or not, it is
-  dnl assumed for windows builds.
+  dnl For Qt5, we can check a header to find out whether Qt is build
+  dnl statically. When Qt is built statically, some plugins must be linked into
+  dnl the final binary as well.
+  dnl With Qt5, languages moved into core and the WindowsIntegration plugin was
+  dnl added.
   dnl _BITCOIN_QT_CHECK_STATIC_PLUGINS does a quick link-check and appends the
   dnl results to QT_LIBS.
   BITCOIN_QT_CHECK([
@@ -113,53 +112,40 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
   TEMP_CXXFLAGS=$CXXFLAGS
   CPPFLAGS="$QT_INCLUDES $CPPFLAGS"
   CXXFLAGS="$PIC_FLAGS $CXXFLAGS"
-  if test "x$bitcoin_qt_got_major_vers" = x5; then
-    _BITCOIN_QT_IS_STATIC
-    if test "x$bitcoin_cv_static_qt" = xyes; then
-      _BITCOIN_QT_FIND_STATIC_PLUGINS
-      AC_DEFINE(QT_STATICPLUGIN, 1, [Define this symbol if qt plugins are static])
-      AC_CACHE_CHECK(for Qt < 5.4, bitcoin_cv_need_acc_widget,[
-        AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
-            #include <QtCore/qconfig.h>
-            #ifndef QT_VERSION
-            #  include <QtCore/qglobal.h>
-            #endif
-          ]],
-          [[
-            #if QT_VERSION >= 0x050400
-            choke
-            #endif
-          ]])],
-        [bitcoin_cv_need_acc_widget=yes],
-        [bitcoin_cv_need_acc_widget=no])
-      ])
-      if test "x$bitcoin_cv_need_acc_widget" = xyes; then
-        _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(AccessibleFactory)], [-lqtaccessiblewidgets])
-      fi
-      _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(QMinimalIntegrationPlugin)],[-lqminimal])
-      AC_DEFINE(QT_QPA_PLATFORM_MINIMAL, 1, [Define this symbol if the minimal qt platform exists])
-      if test "x$TARGET_OS" = xwindows; then
-        _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(QWindowsIntegrationPlugin)],[-lqwindows])
-        AC_DEFINE(QT_QPA_PLATFORM_WINDOWS, 1, [Define this symbol if the qt platform is windows])
-      elif test "x$TARGET_OS" = xlinux; then
-        _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(QXcbIntegrationPlugin)],[-lqxcb -lxcb-static])
-        AC_DEFINE(QT_QPA_PLATFORM_XCB, 1, [Define this symbol if the qt platform is xcb])
-      elif test "x$TARGET_OS" = xdarwin; then
-        AX_CHECK_LINK_FLAG([[-framework IOKit]],[QT_LIBS="$QT_LIBS -framework IOKit"],[AC_MSG_ERROR(could not iokit framework)])
-        _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(QCocoaIntegrationPlugin)],[-lqcocoa])
-        AC_DEFINE(QT_QPA_PLATFORM_COCOA, 1, [Define this symbol if the qt platform is cocoa])
-      fi
+  _BITCOIN_QT_IS_STATIC
+  if test "x$bitcoin_cv_static_qt" = xyes; then
+    _BITCOIN_QT_FIND_STATIC_PLUGINS
+    AC_DEFINE(QT_STATICPLUGIN, 1, [Define this symbol if qt plugins are static])
+    AC_CACHE_CHECK(for Qt < 5.4, bitcoin_cv_need_acc_widget,[
+      AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+          #include <QtCore/qconfig.h>
+          #ifndef QT_VERSION
+          #  include <QtCore/qglobal.h>
+          #endif
+        ]],
+        [[
+          #if QT_VERSION >= 0x050400
+          choke
+          #endif
+        ]])],
+      [bitcoin_cv_need_acc_widget=yes],
+      [bitcoin_cv_need_acc_widget=no])
+    ])
+    if test "x$bitcoin_cv_need_acc_widget" = xyes; then
+      _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(AccessibleFactory)], [-lqtaccessiblewidgets])
     fi
-  else
+    _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(QMinimalIntegrationPlugin)],[-lqminimal])
+    AC_DEFINE(QT_QPA_PLATFORM_MINIMAL, 1, [Define this symbol if the minimal qt platform exists])
     if test "x$TARGET_OS" = xwindows; then
-      AC_DEFINE(QT_STATICPLUGIN, 1, [Define this symbol if qt plugins are static])
-      _BITCOIN_QT_CHECK_STATIC_PLUGINS([
-         Q_IMPORT_PLUGIN(qcncodecs)
-         Q_IMPORT_PLUGIN(qjpcodecs)
-         Q_IMPORT_PLUGIN(qtwcodecs)
-         Q_IMPORT_PLUGIN(qkrcodecs)
-         Q_IMPORT_PLUGIN(AccessibleFactory)],
-         [-lqcncodecs -lqjpcodecs -lqtwcodecs -lqkrcodecs -lqtaccessiblewidgets])
+      _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(QWindowsIntegrationPlugin)],[-lqwindows])
+      AC_DEFINE(QT_QPA_PLATFORM_WINDOWS, 1, [Define this symbol if the qt platform is windows])
+    elif test "x$TARGET_OS" = xlinux; then
+      _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(QXcbIntegrationPlugin)],[-lqxcb -lxcb-static])
+      AC_DEFINE(QT_QPA_PLATFORM_XCB, 1, [Define this symbol if the qt platform is xcb])
+    elif test "x$TARGET_OS" = xdarwin; then
+      AX_CHECK_LINK_FLAG([[-framework IOKit]],[QT_LIBS="$QT_LIBS -framework IOKit"],[AC_MSG_ERROR(could not iokit framework)])
+      _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(QCocoaIntegrationPlugin)],[-lqcocoa])
+      AC_DEFINE(QT_QPA_PLATFORM_COCOA, 1, [Define this symbol if the qt platform is cocoa])
     fi
   fi
   CPPFLAGS=$TEMP_CPPFLAGS
@@ -167,9 +153,7 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
   ])
 
   if test "x$use_pkgconfig$qt_bin_path" = xyes; then
-    if test "x$bitcoin_qt_got_major_vers" = x5; then
-      qt_bin_path="`$PKG_CONFIG --variable=host_bins Qt5Core 2>/dev/null`"
-    fi
+    qt_bin_path="`$PKG_CONFIG --variable=host_bins Qt5Core 2>/dev/null`"
   fi
 
   if test "x$use_hardening" != xno; then
@@ -219,11 +203,11 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
     ])
   fi
 
-  BITCOIN_QT_PATH_PROGS([MOC], [moc-qt${bitcoin_qt_got_major_vers} moc${bitcoin_qt_got_major_vers} moc], $qt_bin_path)
-  BITCOIN_QT_PATH_PROGS([UIC], [uic-qt${bitcoin_qt_got_major_vers} uic${bitcoin_qt_got_major_vers} uic], $qt_bin_path)
-  BITCOIN_QT_PATH_PROGS([RCC], [rcc-qt${bitcoin_qt_got_major_vers} rcc${bitcoin_qt_got_major_vers} rcc], $qt_bin_path)
-  BITCOIN_QT_PATH_PROGS([LRELEASE], [lrelease-qt${bitcoin_qt_got_major_vers} lrelease${bitcoin_qt_got_major_vers} lrelease], $qt_bin_path)
-  BITCOIN_QT_PATH_PROGS([LUPDATE], [lupdate-qt${bitcoin_qt_got_major_vers} lupdate${bitcoin_qt_got_major_vers} lupdate],$qt_bin_path, yes)
+  BITCOIN_QT_PATH_PROGS([MOC], [moc-qt5 moc5 moc], $qt_bin_path)
+  BITCOIN_QT_PATH_PROGS([UIC], [uic-qt5 uic5 uic], $qt_bin_path)
+  BITCOIN_QT_PATH_PROGS([RCC], [rcc-qt5 rcc5 rcc], $qt_bin_path)
+  BITCOIN_QT_PATH_PROGS([LRELEASE], [lrelease-qt5 lrelease5 lrelease], $qt_bin_path)
+  BITCOIN_QT_PATH_PROGS([LUPDATE], [lupdate-qt5 lupdate5 lupdate],$qt_bin_path, yes)
 
   MOC_DEFS='-DHAVE_CONFIG_H -I$(srcdir)'
   case $host in
@@ -262,7 +246,7 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
   ],[
     bitcoin_enable_qt=no
   ])
-  AC_MSG_RESULT([$bitcoin_enable_qt (Qt${bitcoin_qt_got_major_vers})])
+  AC_MSG_RESULT([$bitcoin_enable_qt (Qt5)])
 
   AC_SUBST(QT_PIE_FLAGS)
   AC_SUBST(QT_INCLUDES)
@@ -272,7 +256,7 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
   AC_SUBST(QT_DBUS_LIBS)
   AC_SUBST(QT_TEST_INCLUDES)
   AC_SUBST(QT_TEST_LIBS)
-  AC_SUBST(QT_SELECT, qt${bitcoin_qt_got_major_vers})
+  AC_SUBST(QT_SELECT, qt5)
   AC_SUBST(MOC_DEFS)
 ])
 
@@ -301,7 +285,7 @@ AC_DEFUN([_BITCOIN_QT_CHECK_QT5],[
 ])])
 
 dnl Internal. Check if the linked version of Qt was built as static libs.
-dnl Requires: Qt5. This check cannot determine if Qt4 is static.
+dnl Requires: Qt5.
 dnl Requires: INCLUDES and LIBS must be populated as necessary.
 dnl Output: bitcoin_cv_static_qt=yes|no
 dnl Output: Defines QT_STATICPLUGIN if plugins are static.
@@ -346,58 +330,50 @@ AC_DEFUN([_BITCOIN_QT_CHECK_STATIC_PLUGINS],[
 ])
 
 dnl Internal. Find paths necessary for linking qt static plugins
-dnl Inputs: bitcoin_qt_got_major_vers. 4 or 5.
 dnl Inputs: qt_plugin_path. optional.
 dnl Outputs: QT_LIBS is appended
 AC_DEFUN([_BITCOIN_QT_FIND_STATIC_PLUGINS],[
-  if test "x$bitcoin_qt_got_major_vers" = x5; then
-      if test "x$qt_plugin_path" != x; then
-        QT_LIBS="$QT_LIBS -L$qt_plugin_path/platforms"
-        if test -d "$qt_plugin_path/accessible"; then
-          QT_LIBS="$QT_LIBS -L$qt_plugin_path/accessible"
-        fi
+    if test "x$qt_plugin_path" != x; then
+      QT_LIBS="$QT_LIBS -L$qt_plugin_path/platforms"
+      if test -d "$qt_plugin_path/accessible"; then
+        QT_LIBS="$QT_LIBS -L$qt_plugin_path/accessible"
       fi
-     if test "x$use_pkgconfig" = xyes; then
-     : dnl
-     m4_ifdef([PKG_CHECK_MODULES],[
-       PKG_CHECK_MODULES([QTPLATFORM], [Qt5PlatformSupport], [QT_LIBS="$QTPLATFORM_LIBS $QT_LIBS"])
-       if test "x$TARGET_OS" = xlinux; then
-         PKG_CHECK_MODULES([X11XCB], [x11-xcb], [QT_LIBS="$X11XCB_LIBS $QT_LIBS"])
-         if ${PKG_CONFIG} --exists "Qt5Core >= 5.5" 2>/dev/null; then
-           PKG_CHECK_MODULES([QTXCBQPA], [Qt5XcbQpa], [QT_LIBS="$QTXCBQPA_LIBS $QT_LIBS"])
-         fi
-       elif test "x$TARGET_OS" = xdarwin; then
-         PKG_CHECK_MODULES([QTPRINT], [Qt5PrintSupport], [QT_LIBS="$QTPRINT_LIBS $QT_LIBS"])
+    fi
+   if test "x$use_pkgconfig" = xyes; then
+   : dnl
+   m4_ifdef([PKG_CHECK_MODULES],[
+     PKG_CHECK_MODULES([QTPLATFORM], [Qt5PlatformSupport], [QT_LIBS="$QTPLATFORM_LIBS $QT_LIBS"])
+     if test "x$TARGET_OS" = xlinux; then
+       PKG_CHECK_MODULES([X11XCB], [x11-xcb], [QT_LIBS="$X11XCB_LIBS $QT_LIBS"])
+       if ${PKG_CONFIG} --exists "Qt5Core >= 5.5" 2>/dev/null; then
+         PKG_CHECK_MODULES([QTXCBQPA], [Qt5XcbQpa], [QT_LIBS="$QTXCBQPA_LIBS $QT_LIBS"])
        fi
-     ])
-     else
-       if test "x$TARGET_OS" = xwindows; then
-         AC_CACHE_CHECK(for Qt >= 5.6, bitcoin_cv_need_platformsupport,[
-           AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
-               #include <QtCore/qconfig.h>
-               #ifndef QT_VERSION
-               #  include <QtCore/qglobal.h>
-               #endif
-             ]],
-             [[
-               #if QT_VERSION < 0x050600
-               choke
-               #endif
-             ]])],
-           [bitcoin_cv_need_platformsupport=yes],
-           [bitcoin_cv_need_platformsupport=no])
-         ])
-         if test "x$bitcoin_cv_need_platformsupport" = xyes; then
-           BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}PlatformSupport],[main],,BITCOIN_QT_FAIL(lib${QT_LIB_PREFIX}PlatformSupport not found)))
-         fi
+     elif test "x$TARGET_OS" = xdarwin; then
+       PKG_CHECK_MODULES([QTPRINT], [Qt5PrintSupport], [QT_LIBS="$QTPRINT_LIBS $QT_LIBS"])
+     fi
+   ])
+   else
+     if test "x$TARGET_OS" = xwindows; then
+       AC_CACHE_CHECK(for Qt >= 5.6, bitcoin_cv_need_platformsupport,[
+         AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+             #include <QtCore/qconfig.h>
+             #ifndef QT_VERSION
+             #  include <QtCore/qglobal.h>
+             #endif
+           ]],
+           [[
+             #if QT_VERSION < 0x050600
+             choke
+             #endif
+           ]])],
+         [bitcoin_cv_need_platformsupport=yes],
+         [bitcoin_cv_need_platformsupport=no])
+       ])
+       if test "x$bitcoin_cv_need_platformsupport" = xyes; then
+         BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}PlatformSupport],[main],,BITCOIN_QT_FAIL(lib${QT_LIB_PREFIX}PlatformSupport not found)))
        fi
      fi
-  else
-    if test "x$qt_plugin_path" != x; then
-      QT_LIBS="$QT_LIBS -L$qt_plugin_path/accessible"
-      QT_LIBS="$QT_LIBS -L$qt_plugin_path/codecs"
-    fi
-  fi
+   fi
 ])
 
 dnl Internal. Find Qt libraries using pkg-config.
@@ -406,38 +382,14 @@ dnl         first.
 dnl Inputs: $1: If bitcoin_qt_want_version is "auto", check for this version
 dnl         first.
 dnl Outputs: All necessary QT_* variables are set.
-dnl Outputs: bitcoin_qt_got_major_vers is set to "4" or "5".
 dnl Outputs: have_qt_test and have_qt_dbus are set (if applicable) to yes|no.
 AC_DEFUN([_BITCOIN_QT_FIND_LIBS_WITH_PKGCONFIG],[
   m4_ifdef([PKG_CHECK_MODULES],[
-  auto_priority_version=$1
-  if test "x$auto_priority_version" = x; then
-    auto_priority_version=qt5
-  fi
-    if test "x$bitcoin_qt_want_version" = xqt5 ||  ( test "x$bitcoin_qt_want_version" = xauto && test "x$auto_priority_version" = xqt5 ); then
-      QT_LIB_PREFIX=Qt5
-      bitcoin_qt_got_major_vers=5
-    else
-      QT_LIB_PREFIX=Qt
-      bitcoin_qt_got_major_vers=4
-    fi
+    QT_LIB_PREFIX=Qt5
     qt5_modules="Qt5Core Qt5Gui Qt5Network Qt5Widgets"
-    qt4_modules="QtCore QtGui QtNetwork"
     BITCOIN_QT_CHECK([
-      if test "x$bitcoin_qt_want_version" = xqt5 || ( test "x$bitcoin_qt_want_version" = xauto && test "x$auto_priority_version" = xqt5 ); then
-        PKG_CHECK_MODULES([QT5], [$qt5_modules], [QT_INCLUDES="$QT5_CFLAGS"; QT_LIBS="$QT5_LIBS" have_qt=yes],[have_qt=no])
-      elif test "x$bitcoin_qt_want_version" = xqt4 || ( test "x$bitcoin_qt_want_version" = xauto && test "x$auto_priority_version" = xqt4 ); then
-        PKG_CHECK_MODULES([QT4], [$qt4_modules], [QT_INCLUDES="$QT4_CFLAGS"; QT_LIBS="$QT4_LIBS" ; have_qt=yes], [have_qt=no])
-      fi
+      PKG_CHECK_MODULES([QT5], [$qt5_modules], [QT_INCLUDES="$QT5_CFLAGS"; QT_LIBS="$QT5_LIBS" have_qt=yes],[have_qt=no])
 
-      dnl qt version is set to 'auto' and the preferred version wasn't found. Now try the other.
-      if test "x$have_qt" = xno && test "x$bitcoin_qt_want_version" = xauto; then
-        if test "x$auto_priority_version" = xqt5; then
-          PKG_CHECK_MODULES([QT4], [$qt4_modules], [QT_INCLUDES="$QT4_CFLAGS"; QT_LIBS="$QT4_LIBS" ; have_qt=yes; QT_LIB_PREFIX=Qt; bitcoin_qt_got_major_vers=4], [have_qt=no])
-        else
-          PKG_CHECK_MODULES([QT5], [$qt5_modules], [QT_INCLUDES="$QT5_CFLAGS"; QT_LIBS="$QT5_LIBS" ; have_qt=yes; QT_LIB_PREFIX=Qt5; bitcoin_qt_got_major_vers=5], [have_qt=no])
-        fi
-      fi
       if test "x$have_qt" != xyes; then
         have_qt=no
         BITCOIN_QT_FAIL([Qt dependencies not found])
@@ -458,7 +410,6 @@ dnl from the discovered headers.
 dnl Inputs: bitcoin_qt_want_version (from --with-gui=). The version to use.
 dnl         If "auto", the version will be discovered by _BITCOIN_QT_CHECK_QT5.
 dnl Outputs: All necessary QT_* variables are set.
-dnl Outputs: bitcoin_qt_got_major_vers is set to "4" or "5".
 dnl Outputs: have_qt_test and have_qt_dbus are set (if applicable) to yes|no.
 AC_DEFUN([_BITCOIN_QT_FIND_LIBS_WITHOUT_PKGCONFIG],[
   TEMP_CPPFLAGS="$CPPFLAGS"
@@ -480,13 +431,7 @@ AC_DEFUN([_BITCOIN_QT_FIND_LIBS_WITHOUT_PKGCONFIG],[
     if test "x$bitcoin_qt_want_version" = xauto; then
       _BITCOIN_QT_CHECK_QT5
     fi
-    if test "x$bitcoin_cv_qt5" = xyes || test "x$bitcoin_qt_want_version" = xqt5; then
-      QT_LIB_PREFIX=Qt5
-      bitcoin_qt_got_major_vers=5
-    else
-      QT_LIB_PREFIX=Qt
-      bitcoin_qt_got_major_vers=4
-    fi
+    QT_LIB_PREFIX=Qt5
   ])
 
   BITCOIN_QT_CHECK([
@@ -508,9 +453,7 @@ AC_DEFUN([_BITCOIN_QT_FIND_LIBS_WITHOUT_PKGCONFIG],[
   BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}Core]   ,[main],,BITCOIN_QT_FAIL(lib${QT_LIB_PREFIX}Core not found)))
   BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}Gui]    ,[main],,BITCOIN_QT_FAIL(lib${QT_LIB_PREFIX}Gui not found)))
   BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}Network],[main],,BITCOIN_QT_FAIL(lib${QT_LIB_PREFIX}Network not found)))
-  if test "x$bitcoin_qt_got_major_vers" = x5; then
-    BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}Widgets],[main],,BITCOIN_QT_FAIL(lib${QT_LIB_PREFIX}Widgets not found)))
-  fi
+  BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}Widgets],[main],,BITCOIN_QT_FAIL(lib${QT_LIB_PREFIX}Widgets not found)))
   QT_LIBS="$LIBS"
   LIBS="$TEMP_LIBS"