build: fix building against qt5.4/5.5

Github-Pull: #6471
Rebased-From: fe997df

build-aux/m4/bitcoin_qt.m4

@@ -105,24 +105,40 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
   dnl results to QT_LIBS.
   BITCOIN_QT_CHECK([
   TEMP_CPPFLAGS=$CPPFLAGS
-  CPPFLAGS=$QT_INCLUDES
+  CPPFLAGS="$QT_INCLUDES $CPPFLAGS"
   if test x$bitcoin_qt_got_major_vers = x5; then
     _BITCOIN_QT_IS_STATIC
     if test x$bitcoin_cv_static_qt = xyes; then
       AC_DEFINE(QT_STATICPLUGIN, 1, [Define this symbol if qt plugins are static])
       if test x$qt_plugin_path != x; then
-        QT_LIBS="$QT_LIBS -L$qt_plugin_path/accessible"
         QT_LIBS="$QT_LIBS -L$qt_plugin_path/platforms"
       fi
       if test x$use_pkgconfig = xyes; then
         PKG_CHECK_MODULES([QTPLATFORM], [Qt5PlatformSupport], [QT_LIBS="$QTPLATFORM_LIBS $QT_LIBS"])
       fi
-      _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(AccessibleFactory)], [-lqtaccessiblewidgets])
+      AC_CACHE_CHECK(for Qt < 5.4, bitcoin_cv_need_acc_widget,[AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
+          [[#include <QtCore>]],[[
+          #if QT_VERSION >= 0x050400
+          choke;
+          #endif
+          ]])],
+        [bitcoin_cv_need_acc_widget=yes],
+        [bitcoin_cv_need_acc_widget=no])
+      ])
+      if test "x$bitcoin_cv_need_acc_widget" = "xyes"; then
+        if test x$qt_plugin_path != x; then
+          QT_LIBS="$QT_LIBS -L$qt_plugin_path/accessible"
+        fi
+        _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(AccessibleFactory)], [-lqtaccessiblewidgets])
+      fi
       if test x$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$TARGET_OS = xlinux; then
         PKG_CHECK_MODULES([X11XCB], [x11-xcb], [QT_LIBS="$X11XCB_LIBS $QT_LIBS"])
+        if ${PKG_CONFIG} --exists "Qt5Core >= 5.5" 2>/dev/null; then
+          PKG_CHECK_MODULES([QTXCBQPA], [Qt5XcbQpa], [QT_LIBS="$QTXCBQPA_LIBS $QT_LIBS"])
+        fi
         _BITCOIN_QT_CHECK_STATIC_PLUGINS([Q_IMPORT_PLUGIN(QXcbIntegrationPlugin)],[-lqxcb -lxcb-static])
         AC_DEFINE(QT_QPA_PLATFORM_XCB, 1, [Define this symbol if the qt platform is xcb])
       elif test x$TARGET_OS = xdarwin; then
@@ -381,7 +397,8 @@ AC_DEFUN([_BITCOIN_QT_FIND_LIBS_WITHOUT_PKGCONFIG],[
   BITCOIN_QT_CHECK(AC_CHECK_LIB([z] ,[main],,AC_MSG_WARN([zlib not found. Assuming qt has it built-in])))
   BITCOIN_QT_CHECK(AC_CHECK_LIB([png] ,[main],,AC_MSG_WARN([libpng not found. Assuming qt has it built-in])))
   BITCOIN_QT_CHECK(AC_CHECK_LIB([jpeg] ,[main],,AC_MSG_WARN([libjpeg not found. Assuming qt has it built-in])))
-  BITCOIN_QT_CHECK(AC_CHECK_LIB([pcre16] ,[main],,AC_MSG_WARN([libpcre16 not found. Assuming qt has it built-in])))
+  BITCOIN_QT_CHECK(AC_SEARCH_LIBS([pcre16_exec], [qtpcre pcre16],,AC_MSG_WARN([libpcre16 not found. Assuming qt has it built-in])))
+  BITCOIN_QT_CHECK(AC_SEARCH_LIBS([hb_ot_tags_from_script] ,[qtharfbuzzng harfbuzz],,AC_MSG_WARN([libharfbuzz not found. Assuming qt has it built-in or support is disabled])))
   BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}Core]   ,[main],,BITCOIN_QT_FAIL(lib$QT_LIB_PREFIXCore not found)))
   BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}Gui]    ,[main],,BITCOIN_QT_FAIL(lib$QT_LIB_PREFIXGui not found)))
   BITCOIN_QT_CHECK(AC_CHECK_LIB([${QT_LIB_PREFIX}Network],[main],,BITCOIN_QT_FAIL(lib$QT_LIB_PREFIXNetwork not found)))

src/qt/bitcoin.cpp

@@ -57,7 +57,9 @@ Q_IMPORT_PLUGIN(qtwcodecs)
 Q_IMPORT_PLUGIN(qkrcodecs)
 Q_IMPORT_PLUGIN(qtaccessiblewidgets)
 #else
+#if QT_VERSION < 0x050400
 Q_IMPORT_PLUGIN(AccessibleFactory)
+#endif
 #if defined(QT_QPA_PLATFORM_XCB)
 Q_IMPORT_PLUGIN(QXcbIntegrationPlugin);
 #elif defined(QT_QPA_PLATFORM_WINDOWS)