build, test, doc: Temporarily remove Android-related stuff

Previously, our Android builds were geared towards generating APKs,
which relied on Qt. However, after migrating to C++20, compiling for
Android became unfeasible due to Qt 5.15's compatibility limitations
with NDK only up to r25, which includes an outdated embedded libc++.

All removed stuff will be reinstated after migrating the build system to
CMake and upgrading Qt to version 6.x."

Author: hebasto

build-aux/m4/bitcoin_qt.m4

@@ -70,8 +70,6 @@ AC_DEFUN([BITCOIN_QT_INIT],[
                  [qt_lib_suffix= ]); bitcoin_qt_want_version=qt5],
         [qt_lib_suffix= ])
 
-  AS_CASE([$host], [*android*], [qt_lib_suffix=_$ANDROID_ARCH])
-
   AC_ARG_WITH([qt-incdir],[AS_HELP_STRING([--with-qt-incdir=INC_DIR],[specify qt include path (overridden by pkgconfig)])], [qt_include_path=$withval], [])
   AC_ARG_WITH([qt-libdir],[AS_HELP_STRING([--with-qt-libdir=LIB_DIR],[specify qt lib path (overridden by pkgconfig)])], [qt_lib_path=$withval], [])
   AC_ARG_WITH([qt-plugindir],[AS_HELP_STRING([--with-qt-plugindir=PLUGIN_DIR],[specify qt plugin path (overridden by pkgconfig)])], [qt_plugin_path=$withval], [])
@@ -80,19 +78,10 @@ AC_DEFUN([BITCOIN_QT_INIT],[
 
   AC_ARG_WITH([qtdbus],
     [AS_HELP_STRING([--with-qtdbus],
-    [enable DBus support (default is yes if qt is enabled and QtDBus is found, except on Android)])],
+    [enable DBus support (default is yes if qt is enabled and QtDBus is found)])],
     [use_dbus=$withval],
     [use_dbus=auto])
 
-  dnl Android doesn't support D-Bus and certainly doesn't use it for notifications
-  case $host in
-    *android*)
-      if test "$use_dbus" != "yes"; then
-        use_dbus=no
-      fi
-    ;;
-  esac
-
   AC_SUBST(QT_TRANSLATION_DIR,$qt_translation_path)
 ])
 
@@ -132,16 +121,11 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
       if test -d "$qt_plugin_path/accessible"; then
         QT_LIBS="$QT_LIBS -L$qt_plugin_path/accessible"
       fi
-      if test -d "$qt_plugin_path/platforms/android"; then
-        QT_LIBS="$QT_LIBS -L$qt_plugin_path/platforms/android -lqtfreetype -lEGL"
-      fi
     fi
 
     AC_DEFINE([QT_STATICPLUGIN], [1], [Define this symbol if qt plugins are static])
-    if test "$TARGET_OS" != "android"; then
-      _BITCOIN_QT_CHECK_STATIC_PLUGIN([QMinimalIntegrationPlugin], [-lqminimal])
-      AC_DEFINE([QT_QPA_PLATFORM_MINIMAL], [1], [Define this symbol if the minimal qt platform exists])
-    fi
+    _BITCOIN_QT_CHECK_STATIC_PLUGIN([QMinimalIntegrationPlugin], [-lqminimal])
+    AC_DEFINE([QT_QPA_PLATFORM_MINIMAL], [1], [Define this symbol if the minimal qt platform exists])
     if test "$TARGET_OS" = "windows"; then
       dnl Linking against wtsapi32 is required. See #17749 and
       dnl https://bugreports.qt.io/browse/QTBUG-27097.
@@ -160,9 +144,6 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
       _BITCOIN_QT_CHECK_STATIC_PLUGIN([QCocoaIntegrationPlugin], [-lqcocoa])
       _BITCOIN_QT_CHECK_STATIC_PLUGIN([QMacStylePlugin], [-lqmacstyle])
       AC_DEFINE([QT_QPA_PLATFORM_COCOA], [1], [Define this symbol if the qt platform is cocoa])
-    elif test "$TARGET_OS" = "android"; then
-      QT_LIBS="-Wl,--export-dynamic,--undefined=JNI_OnLoad -lplugins_platforms_qtforandroid${qt_lib_suffix} -ljnigraphics -landroid -lqtfreetype${qt_lib_suffix} $QT_LIBS"
-      AC_DEFINE([QT_QPA_PLATFORM_ANDROID], [1], [Define this symbol if the qt platform is android])
     fi
   fi
   CPPFLAGS=$TEMP_CPPFLAGS
@@ -357,9 +338,6 @@ AC_DEFUN([_BITCOIN_QT_CHECK_STATIC_LIBS], [
     PKG_CHECK_MODULES([QT_SERVICE], [${qt_lib_prefix}ServiceSupport${qt_lib_suffix}], [QT_LIBS="$QT_SERVICE_LIBS $QT_LIBS"])
   elif test "$TARGET_OS" = "windows"; then
     PKG_CHECK_MODULES([QT_WINDOWSUIAUTOMATION], [${qt_lib_prefix}WindowsUIAutomationSupport${qt_lib_suffix}], [QT_LIBS="$QT_WINDOWSUIAUTOMATION_LIBS $QT_LIBS"])
-  elif test "$TARGET_OS" = "android"; then
-    PKG_CHECK_MODULES([QT_EGL], [${qt_lib_prefix}EglSupport${qt_lib_suffix}], [QT_LIBS="$QT_EGL_LIBS $QT_LIBS"])
-    PKG_CHECK_MODULES([QT_SERVICE], [${qt_lib_prefix}ServiceSupport${qt_lib_suffix}], [QT_LIBS="$QT_SERVICE_LIBS $QT_LIBS"])
   fi
 ])
 

ci/test/00_setup_env_android.sh

@@ -86,14 +86,4 @@ if [ -n "$XCODE_VERSION" ] && [ ! -d "${DEPENDS_DIR}/SDKs/${OSX_SDK_BASENAME}" ]
   tar -C "${DEPENDS_DIR}/SDKs" -xf "$OSX_SDK_PATH"
 fi
 
-if [ -n "$ANDROID_HOME" ] && [ ! -d "$ANDROID_HOME" ]; then
-  ANDROID_TOOLS_PATH=${DEPENDS_DIR}/sdk-sources/android-tools.zip
-  if [ ! -f "$ANDROID_TOOLS_PATH" ]; then
-    ${CI_RETRY_EXE} curl --location --fail "${ANDROID_TOOLS_URL}" -o "$ANDROID_TOOLS_PATH"
-  fi
-  mkdir -p "$ANDROID_HOME"
-  unzip -o "$ANDROID_TOOLS_PATH" -d "$ANDROID_HOME"
-  yes | "${ANDROID_HOME}"/cmdline-tools/bin/sdkmanager --sdk_root="${ANDROID_HOME}" --install "build-tools;${ANDROID_BUILD_TOOLS_VERSION}" "platform-tools" "platforms;android-31" "platforms;android-${ANDROID_API_LEVEL}" "ndk;${ANDROID_NDK_VERSION}"
-fi
-
 git config --global ${CFG_DONE} "true"

ci/test/01_base_install.sh

@@ -26,7 +26,6 @@ if [ -z "$DANGER_RUN_CI_ON_HOST" ]; then
   docker volume create "${CONTAINER_NAME}_ccache" || true
   docker volume create "${CONTAINER_NAME}_depends" || true
   docker volume create "${CONTAINER_NAME}_depends_sources" || true
-  docker volume create "${CONTAINER_NAME}_depends_SDKs_android" || true
   docker volume create "${CONTAINER_NAME}_previous_releases" || true
 
   if [ -n "${RESTART_CI_DOCKER_BEFORE_RUN}" ] ; then
@@ -52,7 +51,6 @@ if [ -z "$DANGER_RUN_CI_ON_HOST" ]; then
                   --mount "type=volume,src=${CONTAINER_NAME}_ccache,dst=$CCACHE_DIR" \
                   --mount "type=volume,src=${CONTAINER_NAME}_depends,dst=$DEPENDS_DIR/built" \
                   --mount "type=volume,src=${CONTAINER_NAME}_depends_sources,dst=$DEPENDS_DIR/sources" \
-                  --mount "type=volume,src=${CONTAINER_NAME}_depends_SDKs_android,dst=$DEPENDS_DIR/SDKs/android" \
                   --mount "type=volume,src=${CONTAINER_NAME}_previous_releases,dst=$PREVIOUS_RELEASES_DIR" \
                   --env-file /tmp/env-$USER-$CONTAINER_NAME \
                   --name "$CONTAINER_NAME" \

ci/test/02_run_container.sh

@@ -110,15 +110,6 @@ fi
 ccache --zero-stats
 PRINT_CCACHE_STATISTICS="ccache --version | head -n 1 && ccache --show-stats"
 
-if [ -n "$ANDROID_TOOLS_URL" ]; then
-  make distclean || true
-  ./autogen.sh
-  bash -c "./configure $BITCOIN_CONFIG_ALL $BITCOIN_CONFIG" || ( (cat config.log) && false)
-  make "${MAKEJOBS}" && cd src/qt && ANDROID_HOME=${ANDROID_HOME} ANDROID_NDK_HOME=${ANDROID_NDK_HOME} make apk
-  bash -c "${PRINT_CCACHE_STATISTICS}"
-  exit 0
-fi
-
 BITCOIN_CONFIG_ALL="${BITCOIN_CONFIG_ALL} --enable-external-signer --prefix=$BASE_OUTDIR"
 
 if [ -n "$CONFIG_SHELL" ]; then

ci/test/03_test_script.sh

@@ -778,22 +778,6 @@ case $host in
      dnl "'NSUserNotificationCenter' is deprecated: first deprecated in macOS 11.0".
      OBJCXXFLAGS="$CXXFLAGS -Wno-deprecated-declarations"
      ;;
-   *android*)
-     dnl make sure android stays above linux for hosts like *linux-android*
-     TARGET_OS=android
-     case $host in
-       *x86_64*)
-          ANDROID_ARCH=x86_64
-          ;;
-        *aarch64*)
-          ANDROID_ARCH=arm64-v8a
-          ;;
-        *armv7a*)
-          ANDROID_ARCH=armeabi-v7a
-          ;;
-        *) AC_MSG_ERROR([Could not determine Android arch, or it is unsupported]) ;;
-      esac
-     ;;
    *linux*)
      TARGET_OS=linux
      ;;
@@ -1789,7 +1773,6 @@ AC_SUBST(HAVE_O_CLOEXEC)
 AC_SUBST(HAVE_BUILTIN_PREFETCH)
 AC_SUBST(HAVE_MM_PREFETCH)
 AC_SUBST(HAVE_STRONG_GETAUXVAL)
-AC_SUBST(ANDROID_ARCH)
 AC_SUBST(HAVE_EVHTTP_CONNECTION_GET_PEER_CONST_CHAR)
 AC_CONFIG_FILES([Makefile src/Makefile doc/man/Makefile share/setup.nsi share/qt/Info.plist test/config.ini])
 AC_CONFIG_FILES([contrib/devtools/split-debug.sh],[chmod +x contrib/devtools/split-debug.sh])

configure.ac

@@ -101,10 +101,6 @@ host_os+=$(findstring netbsd,$(full_host_os))
 host_os+=$(findstring openbsd,$(full_host_os))
 host_os+=$(findstring mingw32,$(full_host_os))
 
-ifeq (android,$(findstring android,$(full_host_os)))
-host_os:=android
-endif
-
 host_os:=$(strip $(host_os))
 ifeq ($(host_os),)
 host_os=$(full_host_os)

depends/Makefile

@@ -38,11 +38,8 @@ Common `host-platform-triplet`s for cross compilation are:
 - `riscv32-linux-gnu` for Linux RISC-V 32 bit
 - `riscv64-linux-gnu` for Linux RISC-V 64 bit
 - `s390x-linux-gnu` for Linux S390X
-- `armv7a-linux-android` for Android ARM 32 bit
-- `aarch64-linux-android` for Android ARM 64 bit
-- `x86_64-linux-android` for Android x86 64 bit
 
-The paths are automatically configured and no other options are needed unless targeting [Android](../doc/build-android.md).
+The paths are automatically configured and no other options are needed.
 
 ### Install the required dependencies: Ubuntu & Debian
 

depends/README.md

@@ -5,12 +5,10 @@ boost_packages = boost
 libevent_packages = libevent
 
 qrencode_linux_packages = qrencode
-qrencode_android_packages = qrencode
 qrencode_darwin_packages = qrencode
 qrencode_mingw32_packages = qrencode
 
 qt_linux_packages:=qt expat libxcb xcb_proto libXau xproto freetype fontconfig libxkbcommon libxcb_util libxcb_util_render libxcb_util_keysyms libxcb_util_image libxcb_util_wm
-qt_android_packages=qt
 qt_darwin_packages=qt
 qt_mingw32_packages=qt