Summary: Update Android port

* INSTALL: Document where to find Android installation
instructions.
* configure.ac (CHECK_LISP_OBJECT_TYPE): Pacify
-Wsuggest-attribute=noreturn only on Android.
* cross/ndk-build/README: New file.
* doc/emacs/android.texi (Android):
* doc/emacs/emacs.texi (Top):
* doc/emacs/input.texi (Other Input Devices): Untabify menus.
* etc/NEWS: Move INSTALL.android to java/INSTALL.
* java/INSTALL: New file.
* java/README:
* src/coding.c (from_unicode_buffer): Make Android specific code
only build on Android.

10 files changed, 1309 insertions, 51 deletions

diff --git a/INSTALL b/INSTALL
index 344ae39f464..a69e1f2aec7 100644
--- a/INSTALL
+++ b/INSTALL
@@ -5,9 +5,9 @@ See the end of the file for license conditions.
 
 
 This file contains general information on building GNU Emacs.  For
-more information specific to the MS-Windows, GNUstep/macOS, and MS-DOS
-ports, also read the files nt/INSTALL, nextstep/INSTALL, and
-msdos/INSTALL.
+more information specific to the MS-Windows, GNUstep/macOS, MS-DOS,
+and Android ports, also read the files nt/INSTALL, nextstep/INSTALL,
+msdos/INSTALL, and java/INSTALL.
 
 For information about building from a Git checkout (rather than an
 Emacs release), read the INSTALL.REPO file first.
diff --git a/configure.ac b/configure.ac
index 393f8c72c65..d8772b7803e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1656,9 +1656,6 @@ AS_IF([test $gl_gcc_warnings = no],
   nw="$nw -Wsync-nand"              # irrelevant here, and provokes ObjC warning
   nw="$nw -Wunsafe-loop-optimizations" # OK to suppress unsafe optimizations
   nw="$nw -Wbad-function-cast"      # These casts are no worse than others.
-  nw="$nw -Wunknown-warning-option" # Let #pragma GCC ignore work properly
-				    # even when the compiler in use doesn't
-				    # support the option.
 
   # Emacs doesn't care about shadowing; see
   # <https://lists.gnu.org/r/emacs-diffs/2011-11/msg00265.html>.
@@ -1695,7 +1692,8 @@ AS_IF([test $gl_gcc_warnings = no],
   # currently stubbed out for operation on the build machine, disable
   # -Wsuggest-attribute=noreturn.
 
-  nw="$nw -Wsuggest-attribute=noreturn"
+  AS_IF([test "$ANDROID" = "yes"],
+    [nw="$nw -Wsuggest-attribute=noreturn"])
 
   gl_MANYWARN_ALL_GCC([ws])
   gl_MANYWARN_COMPLEMENT([ws], [$ws], [$nw])
diff --git a/cross/ndk-build/README b/cross/ndk-build/README
new file mode 100644
index 00000000000..9c4ffdf437a
--- /dev/null
+++ b/cross/ndk-build/README
@@ -0,0 +1,352 @@
+NDK BUILD SYSTEM IMPLEMENTATION
+
+Copyright (C) 2023 Free Software Foundation, Inc.
+See the end of the file for license conditions.
+
+Emacs implements ndk-build itself, because the version that comes with
+the Android NDK is not easy to use from another Makefile, and keeps
+accumulating incompatible changes.
+
+The Emacs implementation of ndk-build consists of one m4 file:
+
+  m4/ndk-build.m4
+
+four Makefiles in build-aux, run during configure:
+
+  build-aux/ndk-build-helper-1.mk
+  build-aux/ndk-build-helper-2.mk
+  build-aux/ndk-build-helper-3.mk
+  build-aux/ndk-build-helper.mk
+
+one awk script in build-awx, run during configure:
+
+  build-aux/ndk-module-extract.awk
+
+seven Makefiles in cross/ndk-build,
+
+  cross/ndk-build/ndk-build-shared-library.mk
+  cross/ndk-build/ndk-build-static-library.mk
+  cross/ndk-build/ndk-build-executable.mk
+  cross/ndk-build/ndk-clear-vars.mk
+  cross/ndk-build/ndk-prebuilt-shared-library.mk
+  cross/ndk-build/ndk-prebuilt-static-library.mk
+  cross/ndk-build/ndk-resolve.mk
+
+and finally, two more Makefiles in cross/ndk-build, generated by
+configure:
+
+  cross/ndk-build/Makefile     (generated from cross/ndk-build/Makefile.in)
+  cross/ndk-build/ndk-build.mk (generated from cross/ndk-build/ndk-build.mk.in)
+
+m4/ndk-build.m4 is a collection of macros which are used by the
+configure script to set up the ndk-build system, look for modules, add
+the appropriate options to LIBS and CFLAGS, and generate the Makefiles
+necessary to build the rest of Emacs.
+
+Immediately after determining the list of directories in which to look
+for ``Android.mk'' files, the version and type of Android system being
+built for, configure calls:
+
+  ndk_INIT([$android_abi], [$ANDROID_SDK], [cross/ndk-build])
+
+This expands to a sequence of shell script that enumerates all of the
+Android.mk files specified in "$with_ndk_path", sets up some shell
+functions used by the rest of the ndk-build code run by the configure
+script, and teaches the ndk-build system that the Makefiles to be
+generated are found in the directory "cross/ndk-build/Makefile".
+
+When configure is cross-compiling for Android, the macro
+EMACS_CHECK_MODULES will expand to the macro ndk_CHECK_MODULES,
+instead of pkg-config.m4's PKG_CHECK_MODULES.  Thus, the following
+code:
+
+    EMACS_CHECK_MODULES([PNG], [libpng >= 1.0.0])
+
+will actually expand to:
+
+    ndk_CHECK_MODULES([PNG], [libpng >= 1.0.0], [HAVE_PNG=yes],
+		      [HAVE_PNG=no])
+
+which in turn expands to a sequence shell script that first invokes:
+
+    make -f build-aux/ndk-build-helper.mk
+
+for each ``Android.mk'' file found by ndk_INIT, with the following
+variables given to Make:
+
+    EMACS_SRCDIR=.  # the source directory (in which configure is running)
+    EMACS_ABI=$ndk_ABI # this is the $android_abi given to ndk_INIT
+    ANDROID_MAKEFILE="/opt/android/libpng/Android.mk"
+    ANDROID_MODULE_DIRECTORY="/opt/android/libpng"
+    NDK_BUILD_DIR="$ndk_DIR" # this is the directory given as to ndk_INIT
+
+build-aux/ndk-build-helper.mk will then evaluate the contents
+$(ANDROID_MAKEFILE), the ``Android.mk'' file, for the first time.  The
+purpose of this evaluation is to establish a list of packages (or
+modules) provided by the ``Android.mk'' file, and the corresponding
+Makefile targets and compiler and linker flags required to build and
+link to those tagets.
+
+Before doing so, build-aux/ndk-build-helper.mk will define several
+variables and functions required by all ``Android.mk'' files.  The
+most important of these are:
+
+  my-dir # the directory containing the Android.mk file.
+  BUILD_SHARED_LIBRARY # build-aux/ndk-build-helper-1.mk
+  BUILD_STATIC_LIBRARY # build-aux/ndk-build-helper-2.mk
+  BUILD_EXECUTABLE # build-aux/ndk-build-helper-3.mk
+  CLEAR_VARS # build-aux/ndk-build-helper-4.mk
+
+Then, ``Android.mk'' will include $(CLEAN_VARS), possibly other
+``Android.mk'' files, (to clear variables previously set), set several
+variables describing each module to the ndk-build system, and include
+one of $(BUILD_SHARED_LIBRARY), $(BUILD_STATIC_LIBRARY) and
+$(BUILD_EXECUTABLE).
+
+Each one of those three scripts will then read from the variables set
+by ``Android.mk'', resolve dependencies, and print out some text
+describing the module to Emacs.	 For example, the shared library
+module "libpng" results in the following text being printed:
+
+Building shared
+libpng
+/opt/android/libpng/png.c /opt/android/libpng/pngerror.c /opt/android/libpng/pngget.c /opt/android/libpng/pngmem.c /opt/android/libpng/pngpread.c /opt/android/libpng/pngread.c /opt/android/libpng/pngrio.c /opt/android/libpng/pngrtran.c /opt/android/libpng/pngrutil.c /opt/android/libpng/pngset.c /opt/android/libpng/pngtrans.c /opt/android/libpng/pngwio.c /opt/android/libpng/pngwrite.c /opt/android/libpng/pngwtran.c /opt/android/libpng/pngwutil.c
+-I/opt/android/libpng
+
+  -L/opt/emacs/cross/ndk-build -l:libpng_emacs.so
+libpng_emacs.so
+End
+
+The output is arranged as follows:
+
+  - The first line consists of the word ``Building'', followed by
+    either ``shared'', ``static'', or ``executable'', depending on
+    what type of module being built.
+
+  - The second line consists of the name of the module currently being
+    built.
+
+  - The third line consists of all of the source code files comprising
+    the module.
+
+  - The fourth line consists of the text that has to be added to
+    CFLAGS in order to find the includes associated with the module.
+
+  - The fifth line consists of the text that has to be added to LIBS
+    in order to link with this module and all of its dependencies.
+
+  - The sixth line consists of the Make targets (more on this later)
+    that will build the final shared object or library archive of this
+    module, along with all of its dependencies.
+
+  - The seventh line is either empty, or the name of a dependency on
+    the C++ standard library.  This is used to determine whether or
+    not Emacs will include the C++ standard library in the application
+    package.
+
+The output from Make is given to an awk script,
+build-aux/ndk-module-extract.awk.  This is responsible for parsing the
+that output and filtering out modules other than what is being built:
+
+  awk -f build-aux/ndk-module-extract.awk MODULE=libpng
+
+eventually generating this section of shell script:
+
+module_name=libpng
+module_kind=shared
+module_src="/opt/android/libpng/png.c /opt/android/libpng/pngerror.c /opt/android/libpng/pngget.c /opt/android/libpng/pngmem.c /opt/android/libpng/pngpread.c /opt/android/libpng/pngread.c /opt/android/libpng/pngrio.c /opt/android/libpng/pngrtran.c /opt/android/libpng/pngrutil.c /opt/android/libpng/pngset.c /opt/android/libpng/pngtrans.c /opt/android/libpng/pngwio.c /opt/android/libpng/pngwrite.c /opt/android/libpng/pngwtran.c /opt/android/libpng/pngwutil.c"
+module_includes="-I/opt/android/libpng"
+module_cflags=""
+module_ldflags="  -L/opt/emacs/cross/ndk-build -l:libpng_emacs.so"
+module_target="libpng_emacs.so"
+module_cxx_deps=""
+module_imports=""
+
+which is then evaluated by `configure'.	 Once the variable
+`module_name' is set, configure apends the remaining
+$(module_includes), $(module_cflags) and $(module_ldflags) to the
+module's CFLAGS and LIBS variables, and appends the list of Makefile
+targets specified to the variable NDK_BUILD_MODULES.
+
+In some cases, an ``Android.mk'' file may chose to import a module
+defined in ``--with-ndk-path'', but not defined inside its own
+``Android.mk'' file.  build-aux/ndk-build-helper.mk defines the
+`import-module' function to add the modules being imported to a
+variable, which is then printed out after ``ndk-build-helper.mk''
+completes.  For example, libxml2 imports the ``libicucc'' module,
+which results in the following text being printed:
+
+Building shared
+libxml2
+/home/oldosfan/libxml2/SAX.c /home/oldosfan/libxml2/entities.c /home/oldosfan/libxml2/encoding.c /home/oldosfan/libxml2/error.c /home/oldosfan/libxml2/parserInternals.c /home/oldosfan/libxml2/parser.c /home/oldosfan/libxml2/tree.c /home/oldosfan/libxml2/hash.c /home/oldosfan/libxml2/list.c /home/oldosfan/libxml2/xmlIO.c /home/oldosfan/libxml2/xmlmemory.c /home/oldosfan/libxml2/uri.c /home/oldosfan/libxml2/valid.c /home/oldosfan/libxml2/xlink.c /home/oldosfan/libxml2/debugXML.c /home/oldosfan/libxml2/xpath.c /home/oldosfan/libxml2/xpointer.c /home/oldosfan/libxml2/xinclude.c /home/oldosfan/libxml2/DOCBparser.c /home/oldosfan/libxml2/catalog.c /home/oldosfan/libxml2/globals.c /home/oldosfan/libxml2/threads.c /home/oldosfan/libxml2/c14n.c /home/oldosfan/libxml2/xmlstring.c /home/oldosfan/libxml2/buf.c /home/oldosfan/libxml2/xmlregexp.c /home/oldosfan/libxml2/xmlschemas.c /home/oldosfan/libxml2/xmlschemastypes.c /home/oldosfan/libxml2/xmlunicode.c /home/oldosfan/libxml2/xmlreader.c /home/oldosfan/libxml2/relaxng.c /home/oldosfan/libxml2/dict.c /home/oldosfan/libxml2/SAX2.c /home/oldosfan/libxml2/xmlwriter.c /home/oldosfan/libxml2/legacy.c /home/oldosfan/libxml2/chvalid.c /home/oldosfan/libxml2/pattern.c /home/oldosfan/libxml2/xmlsave.c /home/oldosfan/libxml2/xmlmodule.c /home/oldosfan/libxml2/schematron.c /home/oldosfan/libxml2/SAX.c /home/oldosfan/libxml2/entities.c /home/oldosfan/libxml2/encoding.c /home/oldosfan/libxml2/error.c /home/oldosfan/libxml2/parserInternals.c /home/oldosfan/libxml2/parser.c /home/oldosfan/libxml2/tree.c /home/oldosfan/libxml2/hash.c /home/oldosfan/libxml2/list.c /home/oldosfan/libxml2/xmlIO.c /home/oldosfan/libxml2/xmlmemory.c /home/oldosfan/libxml2/uri.c /home/oldosfan/libxml2/valid.c /home/oldosfan/libxml2/xlink.c /home/oldosfan/libxml2/debugXML.c /home/oldosfan/libxml2/xpath.c /home/oldosfan/libxml2/xpointer.c /home/oldosfan/libxml2/xinclude.c /home/oldosfan/libxml2/DOCBparser.c /home/oldosfan/libxml2/catalog.c /home/oldosfan/libxml2/globals.c /home/oldosfan/libxml2/threads.c /home/oldosfan/libxml2/c14n.c /home/oldosfan/libxml2/xmlstring.c /home/oldosfan/libxml2/buf.c /home/oldosfan/libxml2/xmlregexp.c /home/oldosfan/libxml2/xmlschemas.c /home/oldosfan/libxml2/xmlschemastypes.c /home/oldosfan/libxml2/xmlunicode.c /home/oldosfan/libxml2/xmlreader.c /home/oldosfan/libxml2/relaxng.c /home/oldosfan/libxml2/dict.c /home/oldosfan/libxml2/SAX2.c /home/oldosfan/libxml2/xmlwriter.c /home/oldosfan/libxml2/legacy.c /home/oldosfan/libxml2/chvalid.c /home/oldosfan/libxml2/pattern.c /home/oldosfan/libxml2/xmlsave.c /home/oldosfan/libxml2/xmlmodule.c /home/oldosfan/libxml2/schematron.c
+
+
+  -L/home/oldosfan/emacs-dev/emacs-android/cross/ndk-build -l:libxml2_emacs.so -l:libicuuc_emacs.so
+libxml2_emacs.so libicuuc_emacs.so
+End
+Start Imports
+libicuuc
+End Imports
+
+Upon encountering the ``Start Imports'' section,
+build-aux/ndk-module-extract.awk collects all imports until it
+encounters the line ``End Imports'', at which point it prints:
+
+module_imports="libicuuc"
+
+Then, if the list of imports is not empty, ndk_CHECK_MODULES
+additionally calls itself for each import before appending the
+module's own ``Android.mk'', ensuring that the module's imported
+dependencies are included by $ndk_DIR/Makefile before itself.
+
+Finally, immediately before generating src/Makefile.android, configure
+expands:
+
+  ndk_CONFIG_FILES
+
+to generate $ndk_DIR/Makefile and $ndk_DIR/ndk-build.mk.
+
+Now, the $ndk_DIR directory is set up to build all modules upon which
+depends, and $ndk_DIR/ndk-build.mk includes a list of files required
+to link Emacs, along with the rules to chdir into $ndk_DIR in order to
+build them.
+
+$ndk_DIR/ndk-build.mk is included by cross/src/Makefile
+(Makefile.android) and java/Makefile.  It defines three different
+variables:
+
+  NDK_BUILD_MODULES	the file names of all modules to be built.
+  NDK_BUILD_STATIC	absolute names of all library archives
+			to be built.
+  NDK_BUILD_SHARED	absolute names of all shared libraries to
+			be built.
+
+and then proceeds to define rules to build each of the modules in
+$(NDK_BUILD_MODULES).
+
+cross/src/Makefile arranges to have all dependencies of Emacs not
+already built built before linking ``libemacs.so'' with them.
+
+java/Makefile additionally arranges to have all shared object
+dependencies built before the application package is built, which is
+normally redundant because they should have already been built before
+linking ``libemacs.so''.
+
+Building the modules is performed through $ndk_DIR/Makefile, which
+contains the actual implementation of the ``ndk-build'' build system.
+First, it defines certain variables constant within the ``ndk-build''
+build system, such as the files included by ``Android.mk'' to build
+shared or static libraries, and CLEAR_VARS.  The most important of
+these are:
+
+  CLEAR_VARS			cross/ndk-build/ndk-clear-vars.mk
+  BUILD_EXECUTABLE		cross/ndk-build/ndk-build-executable.mk
+  BUILD_SHARED_LIBRARY		cross/ndk-build/ndk-build-shared-library.mk
+  BUILD_STATIC_LIBRARY		cross/ndk-build/ndk-build-static-library.mk
+  PREBUILT_SHARED_LIBRARY	cross/ndk-build/ndk-prebuilt-shared-library.mk
+  PREBUILT_STATIC_LIBRARY	cross/ndk-build/ndk-prebuilt-static-library.mk
+
+Then, it loads each Emacs dependency's ``Android.mk'' file.  For each
+module defined there, ``Android.mk'' includes $(CLEAR_VARS) to unset
+all variables specific to each module, and then includes
+$(BUILD_SHARED_LIBRARY) or $(BUILD_STATIC_LIBRARY) for each shared or
+static library module.
+
+This results in cross/ndk-build/ndk-build-shared-library.mk or
+cross/ndk-build/ndk-build-static-library being included, just like the
+Makefiles in build-aux were inside the configure script.
+
+Each one of those two scripts then defines rules to build all of the
+object files associated with the module, and then link or archive
+them.  The name under which the module is linked is the same as the
+Make target found on the sixth line of output from
+build-aux/ndk-build-helper.mk.
+
+In doing so, they both include the file ndk-resolve.mk.
+ndk-resolve.mk is expected to recursively add all of the exported
+CFLAGS and includes of any dependencies to the compiler and linker
+command lines for the module being built.
+
+When building a shared library module, ndk-resolve.mk is also expected
+to define the variables NDK_LOCAL_A_NAMES_$(LOCAL_MODULE) and
+NDK_WHOLE_A_NAMES_$(LOCAL_MODULE), containing all static library
+dependencies' archive files.  They are to be linked in to the
+resulting shared object file.
+
+This is done by including cross/ndk-build/ndk-resolve.mk each time a
+shared or static library module is going to be built.  How is this
+done?
+
+First, ndk-resolve.mk saves the LOCAL_PATH, LOCAL_STATIC_LIBRARIES,
+LOCAL_SHARED_LIBRARIES, LOCAL_EXPORT_CFLAGS and
+LOCAL_EXPORT_C_INCLUDES from the module.
+
+Next, ndk-resolve loops through the dependencies the module has
+specified, appending its CFLAGS and includes to the command line for
+the current module.
+
+Then, that process is repeated for each such dependency which has not
+already been resolved, until all dependencies have been resolved.
+
+libpng is a very simple module, providing only a single shared object
+module.	 This module is named libpng_emacs.so and is eventually built
+and packaged into the library directory of the Emacs application
+package.  Now, let us look at a more complex module, libwebp:
+
+
+
+When built with libwebp, Emacs depends on a single library,
+libwebpdemux.  This library is named ``libwebpdemux'' on Unix systems,
+and that is the name by which it is found with pkg-config.
+
+However, the library's module is only named ``webpdemux'' on Android.
+When ndk_CHECK_MODULES begins to look for a module, it first tries to
+see if its name is found in the variable `ndk_package_map', which was
+set inside ndk_INIT.  In this case, it finds the following word:
+
+  libwebpdemux:webpdemux
+
+and immediately replaces ``libwebpdemux'' with ``webpdemux''.
+
+Then, it locates the ``Android.mk'' file containing a static library
+module named webpdemux and gives the output from
+build-aux/ndk-build-helper.mk to the awk script, resulting in:
+
+module_name=webpdemux
+module_kind=static
+module_src="/opt/android/webp/src/demux/anim_decode.c /opt/android/webp/src/demux/demux.c"
+module_includes="-I/opt/android/webp/src"
+module_cflags=""
+module_ldflags=" cross/ndk-build/libwebpdemux.a cross/ndk-build/libwebp.a cross/ndk-build/libwebpdecoder_static.a "
+module_target="libwebpdemux.a libwebp.a libwebpdecoder_static.a"
+
+The attentive reader will notice that in addition to the
+``libwebpdemux.a'' archive associated with the ``webpdemux'' library,
+Emacs has been made to link with two additional libraries.  This is
+because the ``webpdemux'' module specifies a dependency on the
+``webp'' module (defined in the same Android.mk).
+build-aux/ndk-build-helper.mk resolved that dependency, noticing that
+it in turn specified another dependency on ``webpdecoder_static'',
+which in turn was added to the linker command line and list of targets
+to build.
+
+As a result, all three dependencies will be built and linked to Emacs,
+instead of just the single ``webpdemux'' dependency that was
+specified.
+
+
+
+This file is part of GNU Emacs.
+
+GNU Emacs is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+GNU Emacs is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
diff --git a/doc/emacs/android.texi b/doc/emacs/android.texi
index 8d0707a5075..d49e0754b0a 100644
--- a/doc/emacs/android.texi
+++ b/doc/emacs/android.texi
@@ -14,13 +14,13 @@ or digitizer device and on-screen keyboard.  For more information
 about using such devices with Emacs, @pxref{Other Input Devices}.
 
 @menu
-* What is Android?::		Preamble.
-* Android Startup::		Starting up Emacs on Android.
-* Android Environment::		Running Emacs under Android.
-* Android File System::		The Android file system.
-* Android Windowing::   	The Android window system.
-* Android Fonts::		Font selection under Android.
-* Android Troubleshooting::	Dealing with problems.
+* What is Android?::            Preamble.
+* Android Startup::             Starting up Emacs on Android.
+* Android Environment::         Running Emacs under Android.
+* Android File System::         The Android file system.
+* Android Windowing::           The Android window system.
+* Android Fonts::               Font selection under Android.
+* Android Troubleshooting::     Dealing with problems.
 @end menu
 
 @node What is Android?
diff --git a/doc/emacs/emacs.texi b/doc/emacs/emacs.texi
index 8b3748b8fc0..766180c2e17 100644
--- a/doc/emacs/emacs.texi
+++ b/doc/emacs/emacs.texi
@@ -225,7 +225,7 @@ Appendices
 * Haiku::               Using Emacs on Haiku.
 * Android::             Using Emacs on Android.
 * Microsoft Windows::   Using Emacs on Microsoft Windows and MS-DOS.
-* Other Input Devices::	Using Emacs with other input devices.
+* Other Input Devices:: Using Emacs with other input devices.
 * Manifesto::           What's GNU?  Gnu's Not Unix!
 
 * Glossary::            Terms used in this manual.
@@ -1264,18 +1264,18 @@ Emacs and Haiku
 
 Emacs and Android
 
-* What is Android?::		Preamble.
-* Android Startup::		Starting up Emacs on Android.
-* Android Environment::		Running Emacs under Android.
-* Android File System::		The Android file system.
-* Android Windowing::   	The Android window system.
-* Android Fonts::		Font selection under Android.
-* Android Troubleshooting::	Dealing with problems.
+* What is Android?::            Preamble.
+* Android Startup::             Starting up Emacs on Android.
+* Android Environment::         Running Emacs under Android.
+* Android File System::         The Android file system.
+* Android Windowing::           The Android window system.
+* Android Fonts::               Font selection under Android.
+* Android Troubleshooting::     Dealing with problems.
 
 Emacs and unconventional input devices
 
-* Touchscreens::	Using Emacs on touchscreens.
-* On-Screen Keyboards::	Using Emacs with virtual keyboards.
+* Touchscreens::        Using Emacs on touchscreens.
+* On-Screen Keyboards:: Using Emacs with virtual keyboards.
 
 Emacs and Microsoft Windows/MS-DOS
 
diff --git a/doc/emacs/input.texi b/doc/emacs/input.texi
index dc1acaedfcb..1bf230354b3 100644
--- a/doc/emacs/input.texi
+++ b/doc/emacs/input.texi
@@ -15,8 +15,8 @@ holds true.  As a result, Emacs now has support for other kinds of
 input devices, which is detailed here.
 
 @menu
-* Touchscreens::		Using Emacs on touchscreens.
-* On-Screen Keyboards::		Using Emacs with virtual keyboards.
+* Touchscreens::                Using Emacs on touchscreens.
+* On-Screen Keyboards::         Using Emacs with virtual keyboards.
 @end menu
 
 @node Touchscreens
diff --git a/etc/NEWS b/etc/NEWS
index 139bc1fb457..9ed079a316c 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -28,7 +28,7 @@ applies, and please also update docstrings as needed.
 This requires Emacs to be compiled on another computer.  The Android
 NDK, SDK, and a suitable Java compiler must also be installed.
 
-See the file 'INSTALL.android' for more details.
+See the file 'java/INSTALL' for more details.
 
 
 * Startup Changes in Emacs 30.1
diff --git a/java/INSTALL b/java/INSTALL
new file mode 100644
index 00000000000..bc5f4a70cd0
--- /dev/null
+++ b/java/INSTALL
@@ -0,0 +1,910 @@
+Installation instructions for Android
+Copyright (C) 2023 Free Software Foundation, Inc.
+See the end of the file for license conditions.
+
+Please read the entirety of this file before attempting to build Emacs
+as an application package which can run on Android devices.
+
+When building from the source repository, make sure to read
+INSTALL.REPO as well.
+
+
+
+Android is an unusual operating system in that program binaries cannot
+be produced on computers running Android themselves.  Instead, they
+must be built on some other computer using a set of tools known as the
+``Android SDK'' (Software Development Kit) and the ``Android NDK''
+(Native Development Kit.)  Appropriate versions of both must be
+obtained to build GNU Emacs; after being built, the generated binaries
+will work on almost all Android devices.  This document does not
+elaborate on how both sets of tools can be obtained.  However, for
+your freedom's sake, you should use the Android SDK provided by the
+Debian project.
+
+In addition to the Android SDK and Android NDK, Emacs also requires
+the Java compiler from OpenJDK 1.7.0 to be installed on your system.
+Building on GNU systems is all that is officially supported.  We are
+told that Mac OS works too, and other Unix systems will likely work
+as well, but MS Windows and Cygwin will not.
+
+Once all of those tools are obtained, you may invoke the `configure'
+script like so:
+
+  ./configure --with-android=/path/to/android.jar \
+	      ANDROID_CC=/path/to/android/ndk/cc  \
+	      SDK_BUILD_TOOLS=/path/to/sdk/build/tools
+
+Replacing the paths in the command line above with:
+
+  - the path to the `android.jar' headers which come with the Android
+    SDK.  They must correspond to Android version 13 (API level 33) or
+    later.
+
+  - the path to the C compiler in the Android NDK, for the kind of CPU
+    you are building Emacs to run on.
+
+  - the path to the directory in the Android SDK containing binaries
+    such as `aapt', `apksigner', and `d8'.  These are used to build
+    the application package.
+
+Where the type of CPU can either be `armeabi', `armv7*', `i686',
+`x86_64', `mips', or `mips64'.
+
+After the configuration process completes, you may run:
+
+  make all
+
+Once `make' finishes, there should be a file in the `java' directory
+named along the lines of:
+
+  emacs-<version>-<api-version>-<abi>.apk
+
+where <api-version> is the oldest version of Android that the package
+will run on, and <abi> is the type of Android machine the package was
+built for.
+
+The generated package can be uploaded onto an SD card (or similar
+medium) and installed on-device.
+
+
+BUILDING WITH OLD NDK VERSIONS
+
+Building Emacs with an old version of the Android NDK requires special
+setup.	This is because there is no separate C compiler binary for
+each version of Android in those versions of the NDK.
+
+Before running `configure', you must identify three variables:
+
+  - What kind of Android system you are building Emacs for.
+
+  - The minimum API version of Android you want to build Emacs for.
+
+  - The locations of the system root and include files for that
+    version of Android in the NDK.
+
+That information must then be specified as arguments to the NDK C
+compiler.  For example:
+
+  ./configure [...] \
+     ANDROID_CC="i686-linux-android-gcc \
+		 --sysroot=/path/to/ndk/platforms/android-14/arch-x86/"
+     ANDROID_CFLAGS="-isystem /path/to/ndk/sysroot/usr/include \
+		     -isystem /path/to/ndk/sysroot/usr/include/i686-linux-android \
+		     -D__ANDROID_API__=14"
+
+Where __ANDROID_API__ and the version identifier in
+"platforms/android-14" defines the version of Android you are building
+for, and the include directories specify the paths to the relevant
+Android headers.  In addition, it may be necessary to specify
+"-gdwarf-2", due to a bug in the Android NDK.
+
+Even older versions of the Android SDK do not require the extra
+`-isystem' directives.
+
+Emacs is known to run on Android 2.2 (API version 8) or later, with
+the NDK r10b or later.  We wanted to make Emacs work on even older
+versions of Android, but they are missing the required JNI graphics
+library that allows Emacs to display text from C code.
+
+Due to an extremely nasty bug in the Android 2.2 system, the generated
+Emacs package cannot be compressed in builds for Android 2.2.  As a
+result, the Emacs package will be approximately 100 megabytes larger
+than a compressed package for a newer version of Android.
+
+
+DEBUG AND RELEASE BUILDS
+
+Android makes a distinction between ``debug'' and ``release'' builds
+of applications.  With ``release'' builds, the system will apply
+stronger optimizations to the application at the cost of being unable
+to debug them with the steps in etc/DEBUG.
+
+Emacs is built as a debuggable package by default, but:
+
+      ./configure --without-android-debug
+
+will create a release build of Emacs instead.  This may be useful when
+running Emacs on resource constrained machines.
+
+If you are building an Emacs package for redistribution, we urge you
+to provide both debug and release versions.
+
+
+BUILDING WITH THIRD PARTY LIBRARIES
+
+The Android NDK does not support the usual ways of locating third
+party libraries, especially not via `pkg-config'.  Instead, it uses
+its own system called `ndk-build'.  The one exception to this rule is
+zlib, which is considered a part of the Android OS itself and is
+available on all devices running Android.
+
+Android also requires that each application include its own
+dependencies, as the system makes no guarantee about the existence of
+any particular library.
+
+Emacs is not built with the `ndk-build' system.	 Instead, it is built
+with Autoconf and Make.
+
+However, it supports building and including dependencies which use the
+similarly Make-based `ndk-build' system.
+
+To use dependencies built through `ndk-build', you must specify a list
+of directories within which Emacs will search for ``Android.mk''
+files, like so:
+
+  ./configure "--with-ndk-path=directory1 directory2"
+
+If `configure' complains about not being able to find
+``libc++_shared.so'', then you must locate that file in your copy of
+the NDK, and specify it like so:
+
+  ./configure --with-ndk-cxx-shared=/path/to/sysroot/libc++_shared.so
+
+Emacs will then read the ``Android.mk'' file in each directory, and
+automatically build and use those modules.
+
+When building for Intel systems, some ``ndk-build'' modules require
+the Netwide Assembler, usually installed under ``nasm'', to be present
+on the system that is building Emacs.
+
+Google, Inc. has adapted many common Emacs dependencies to use the
+`ndk-build' system.  Here is a non-exhaustive list of what is known to
+work, along with what has to be patched to make them work:
+
+  libpng	- https://android.googlesource.com/platform/external/libpng
+  libwebp	- https://android.googlesource.com/platform/external/webp
+     (You must apply the patch at the end of this file for the resulting
+      binary to work on armv7 devices.)
+  giflib	- https://android.googlesource.com/platform/external/giflib
+     (You must add LOCAL_EXPORT_CFLAGS := -I$(LOCAL_PATH) before
+      its Android.mk includes $(BUILD_STATIC_LIBRARY))
+  libjpeg-turbo - https://android.googlesource.com/platform/external/libjpeg-turbo
+     (You must add LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH) before
+      its Android.mk includes $(BUILD_SHARED_LIBRARY))
+  libxml2	- https://android.googlesource.com/platform/external/libxml2/
+     (You must also place the dependency icu4c in ``--with-ndk-path'',
+      and apply the patch at the end of this file.)
+  icu4c		- https://android.googlesource.com/platform/external/icu/
+     (You must apply the patch at the end of this file.)
+  sqlite3	- https://android.googlesource.com/platform/external/sqlite/
+     (You must apply the patch at the end of this file, and add the `dist'
+      directory to ``--with-ndk-path''.)
+  libselinux	- https://android.googlesource.com/platform/external/libselinux
+     (You must apply the patches at the end of the file, and obtain
+      the following three dependencies.)
+  libpackagelistparser
+    https://android.googlesource.com/platform/system/core/+/refs/heads/nougat-mr1-dev/libpackagelistparser/
+  libpcre	- https://android.googlesource.com/platform/external/pcre
+  libcrypto	- https://android.googlesource.com/platform/external/boringssl
+     (You must apply the patch at the end of this file when building for
+      ARM systems.)
+
+Many of these dependencies have been migrated over to the
+``Android.bp'' build system now used to build Android itself.
+However, the old ``Android.mk'' Makefiles are still present in older
+branches, and can be easily adapte to newer versions.
+
+In addition, some Emacs dependencies provide `ndk-build' support
+themselves:
+
+  libjansson	- https://github.com/akheron/jansson
+    (You must add LOCAL_EXPORT_INCLUDES := $(LOCAL_C_INCLUDES) before
+     its Android.mk includes $(BUILD_SHARED_LIBRARY), then copy
+     android/jansson_config.h to android/jansson_private_config.h.)
+
+Emacs developers have ported the following dependencies to ARM Android
+systems:
+
+  gnutls, gmp	- https://sourceforge.net/projects/android-ports-for-gnu-emacs
+    (Please see the section GNUTLS near the end of this file.)
+  libtiff    	- https://sourceforge.net/projects/android-ports-for-gnu-emacs
+    (Extract and point ``--with-ndk-path'' to tiff-4.5.0-emacs.tar.gz.)
+  tree-sitter	- https://sourceforge.net/projects/android-ports-for-gnu-emacs
+    (Please see the section TREE-SITTER near the end of this file.)
+
+And other developers have ported the following dependencies to Android
+systems:
+
+  ImageMagick, lcms2 - https://github.com/MolotovCherry/Android-ImageMagick7
+    (Please see the section IMAGEMAGICK near the end of this file.)
+
+We anticipate that most untested non-trivial ndk-build dependencies
+will need adjustments in Emacs to work, as the Emacs build system
+which emulates ndk-build is in an extremely early state.
+
+
+GNUTLS
+
+Modified copies of GnuTLS and its dependencies (such as libgmp,
+libtasn1, p11-kit) which can be built with the ndk-build system can be
+found at https://sourceforge.net/projects/android-ports-for-gnu-emacs.
+
+They have only been tested on arm64 Android systems running Android
+5.0 or later, and armv7l systems running Android 13 or later, so your
+mileage may vary, especially if you are trying to build Emacs for
+another kind of machine.
+
+To build Emacs with GnuTLS, you must unpack each of the following tar
+archives in that site:
+
+  gmp-6.2.1-emacs.tgz
+  gnutls-3.7.8-emacs.tar.gz
+  libtasn1-4.19.0-emacs.tar.gz
+  p11-kit-0.24.1-emacs.tar.gz
+  nettle-3.8-emacs.tar.gz
+
+and add the resulting folders to ``--with-ndk-path''.  Note that you
+should not try to build these packages separately using any
+`configure' script or Makefiles inside.
+
+
+TREE-SITTER
+
+A copy of tree-sitter modified to build with the ndk-build system can
+also find that URL.  To build Emacs with tree-sitter, you must unpack
+the following tar archive in that site:
+
+  tree-sitter-0.20.7-emacs.tar.gz
+
+and add the resulting folder to ``--with-ndk-build''.
+
+
+IMAGEMAGICK
+
+There is a third party port of ImageMagick to Android.  Unfortunately,
+the port also uses its own patched versions of libpng, libjpeg,
+libtiff and libwebp, which conflict with those used by Emacs.  Its
+Makefiles were also written for MS Windows, so you must also apply the
+patch at the end of this file.
+
+
+
+PATCH FOR LIBXML2
+
+This patch must be applied to the Android.mk in Google's version of
+libxml2 before it can be built for Emacs.  In addition, you must also
+revert the commit `edb5870767fed8712a9b77ef34097209b61ab2db'.
+
+diff --git a/Android.mk b/Android.mk
+index 07c7b372..24f67e49 100644
+--- a/Android.mk
++++ b/Android.mk
+@@ -80,6 +80,7 @@ LOCAL_SHARED_LIBRARIES := libicuuc
+ LOCAL_MODULE:= libxml2
+ LOCAL_CLANG := true
+ LOCAL_ADDITIONAL_DEPENDENCIES += $(LOCAL_PATH)/Android.mk
++LOCAL_EXPORT_C_INCLUDES += $(LOCAL_PATH)
+ include $(BUILD_SHARED_LIBRARY)
+ 
+ # For the host
+@@ -94,3 +95,5 @@ LOCAL_MODULE := libxml2
+ LOCAL_CLANG := true
+ LOCAL_ADDITIONAL_DEPENDENCIES += $(LOCAL_PATH)/Android.mk
+ include $(BUILD_HOST_STATIC_LIBRARY)
++
++$(call import-module,libicuuc)
+
+PATCH FOR ICU
+
+This patch must be applied to icu4j/Android.mk in Google's version of
+icu before it can be built for Emacs.
+
+diff --git a/icu4j/Android.mk b/icu4j/Android.mk
+index d1ab3d5..69eff81 100644
+--- a/icu4j/Android.mk
++++ b/icu4j/Android.mk
+@@ -69,7 +69,7 @@ include $(BUILD_STATIC_JAVA_LIBRARY)
+ # Path to the ICU4C data files in the Android device file system:
+ icu4c_data := /system/usr/icu
+ icu4j_config_root := $(LOCAL_PATH)/main/classes/core/src
+-include external/icu/icu4j/adjust_icudt_path.mk
++include $(LOCAL_PATH)/adjust_icudt_path.mk
+ 
+ include $(CLEAR_VARS)
+ LOCAL_SRC_FILES := $(icu4j_src_files)
+
+diff --git a/icu4c/source/common/Android.mk b/icu4c/source/common/Android.mk
+index 8e5f757..44bb130 100644
+--- a/icu4c/source/common/Android.mk
++++ b/icu4c/source/common/Android.mk
+@@ -231,7 +231,7 @@ include $(CLEAR_VARS)
+ LOCAL_SRC_FILES += $(src_files)
+ LOCAL_C_INCLUDES += $(c_includes) $(optional_android_logging_includes)
+ LOCAL_CFLAGS += $(local_cflags) -DPIC -fPIC
+-LOCAL_SHARED_LIBRARIES += libdl $(optional_android_logging_libraries)
++LOCAL_SHARED_LIBRARIES += libdl libstdc++ $(optional_android_logging_libraries)
+ LOCAL_MODULE_TAGS := optional
+ LOCAL_MODULE := libicuuc
+ LOCAL_RTTI_FLAG := -frtti
+
+PATCH FOR SQLITE3
+
+diff --git a/dist/Android.mk b/dist/Android.mk
+index bf277d2..36734d9 100644
+--- a/dist/Android.mk
++++ b/dist/Android.mk
+@@ -141,6 +141,7 @@ include $(BUILD_HOST_EXECUTABLE)
+ include $(CLEAR_VARS)
+ LOCAL_SRC_FILES := $(common_src_files)
+ LOCAL_CFLAGS += $(minimal_sqlite_flags)
++LOCAL_EXPORT_C_INCLUDES += $(LOCAL_PATH)
+ LOCAL_MODULE:= libsqlite_static_minimal
+ LOCAL_SDK_VERSION := 23
+ include $(BUILD_STATIC_LIBRARY)
+
+diff --git a/dist/sqlite3.c b/dist/sqlite3.c
+index b0536a4..8fa1ee9 100644
+--- a/dist/sqlite3.c
++++ b/dist/sqlite3.c
+@@ -26474,7 +26474,7 @@ SQLITE_PRIVATE const char *sqlite3OpcodeName(int i){
+ */
+ #if !defined(HAVE_POSIX_FALLOCATE) \
+       && (_XOPEN_SOURCE >= 600 || _POSIX_C_SOURCE >= 200112L)
+-# define HAVE_POSIX_FALLOCATE 1
++/* # define HAVE_POSIX_FALLOCATE 1 */
+ #endif
+ 
+ /*
+
+PATCH FOR WEBP
+
+diff --git a/Android.mk b/Android.mk
+index c7bcb0f5..d4da1704 100644
+--- a/Android.mk
++++ b/Android.mk
+@@ -28,9 +28,10 @@ ifneq ($(findstring armeabi-v7a, $(TARGET_ARCH_ABI)),)
+   # Setting LOCAL_ARM_NEON will enable -mfpu=neon which may cause illegal
+   # instructions to be generated for armv7a code. Instead target the neon code
+   # specifically.
+-  NEON := c.neon
+-  USE_CPUFEATURES := yes
+-  WEBP_CFLAGS += -DHAVE_CPU_FEATURES_H
++  # NEON := c.neon
++  # USE_CPUFEATURES := yes
++  # WEBP_CFLAGS += -DHAVE_CPU_FEATURES_H
++  NEON := c
+ else
+   NEON := c
+ endif
+
+PATCHES FOR SELINUX
+
+diff --git a/Android.mk b/Android.mk
+index 659232e..1e64fd6 100644
+--- a/Android.mk
++++ b/Android.mk
+@@ -116,3 +116,7 @@ LOCAL_STATIC_LIBRARIES := libselinux
+ LOCAL_WHOLE_STATIC_LIBRARIES := libpcre
+ LOCAL_C_INCLUDES := external/pcre
+ include $(BUILD_HOST_EXECUTABLE)
++
++$(call import-module,libpcre)
++$(call import-module,libpackagelistparser)
++$(call import-module,libcrypto)
+
+diff --git a/src/android.c b/src/android.c
+index 5206a9f..b351ffc 100644
+--- a/src/android.c
++++ b/src/android.c
+@@ -21,8 +21,7 @@
+ #include <selinux/label.h>
+ #include <selinux/avc.h>
+ #include <openssl/sha.h>
+-#include <private/android_filesystem_config.h>
+-#include <log/log.h>
++#include <android/log.h>
+ #include "policy.h"
+ #include "callbacks.h"
+ #include "selinux_internal.h"
+@@ -686,6 +685,7 @@ static int seapp_context_lookup(enum seapp_kind kind,
+ 		seinfo = parsedseinfo;
+ 	}
+ 
++#if 0
+ 	userid = uid / AID_USER;
+ 	isOwner = (userid == 0);
+ 	appid = uid % AID_USER;
+@@ -702,9 +702,13 @@ static int seapp_context_lookup(enum seapp_kind kind,
+ 		username = "_app";
+ 		appid -= AID_APP;
+ 	} else {
++#endif
+ 		username = "_isolated";
++		appid = 0;
++#if 0
+ 		appid -= AID_ISOLATED_START;
+ 	}
++#endif
+ 
+ 	if (appid >= CAT_MAPPING_MAX_ID || userid >= CAT_MAPPING_MAX_ID)
+ 		goto err;
+@@ -1662,8 +1666,10 @@ int selinux_log_callback(int type, const char *fmt, ...)
+ 
+     va_start(ap, fmt);
+     if (vasprintf(&strp, fmt, ap) != -1) {
++#if 0
+         LOG_PRI(priority, "SELinux", "%s", strp);
+         LOG_EVENT_STRING(AUDITD_LOG_TAG, strp);
++#endif
+         free(strp);
+     }
+     va_end(ap);
+
+PATCH FOR BORINGSSL
+
+diff --git a/Android.mk b/Android.mk
+index 3e3ef2a..277d4a9 100644
+--- a/Android.mk
++++ b/Android.mk
+@@ -27,7 +27,9 @@ LOCAL_MODULE := libcrypto
+ LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/src/include
+ LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk $(LOCAL_PATH)/crypto-sources.mk
+ LOCAL_CFLAGS += -fvisibility=hidden -DBORINGSSL_SHARED_LIBRARY -DBORINGSSL_IMPLEMENTATION -DOPENSSL_SMALL -Wno-unused-parameter
++LOCAL_CFLAGS_arm = -DOPENSSL_STATIC_ARMCAP -DOPENSSL_NO_ASM
+ LOCAL_SDK_VERSION := 9
++LOCAL_LDFLAGS = --no-undefined
+ # sha256-armv4.S does not compile with clang.
+ LOCAL_CLANG_ASFLAGS_arm += -no-integrated-as
+ LOCAL_CLANG_ASFLAGS_arm64 += -march=armv8-a+crypto
+diff --git a/sources.mk b/sources.mk
+index e82f3d5..be3a3c4 100644
+--- a/sources.mk
++++ b/sources.mk
+@@ -337,20 +337,20 @@ linux_aarch64_sources := \
+   linux-aarch64/crypto/sha/sha256-armv8.S\
+   linux-aarch64/crypto/sha/sha512-armv8.S\
+ 
+-linux_arm_sources := \
+-  linux-arm/crypto/aes/aes-armv4.S\
+-  linux-arm/crypto/aes/aesv8-armx32.S\
+-  linux-arm/crypto/aes/bsaes-armv7.S\
+-  linux-arm/crypto/bn/armv4-mont.S\
+-  linux-arm/crypto/modes/ghash-armv4.S\
+-  linux-arm/crypto/modes/ghashv8-armx32.S\
+-  linux-arm/crypto/sha/sha1-armv4-large.S\
+-  linux-arm/crypto/sha/sha256-armv4.S\
+-  linux-arm/crypto/sha/sha512-armv4.S\
+-  src/crypto/chacha/chacha_vec_arm.S\
+-  src/crypto/cpu-arm-asm.S\
+-  src/crypto/curve25519/asm/x25519-asm-arm.S\
+-  src/crypto/poly1305/poly1305_arm_asm.S\
++# linux_arm_sources := \
++#   linux-arm/crypto/aes/aes-armv4.S\
++#   linux-arm/crypto/aes/aesv8-armx32.S\
++#   linux-arm/crypto/aes/bsaes-armv7.S\
++#   linux-arm/crypto/bn/armv4-mont.S\
++#   linux-arm/crypto/modes/ghash-armv4.S\
++#   linux-arm/crypto/modes/ghashv8-armx32.S\
++#   linux-arm/crypto/sha/sha1-armv4-large.S\
++#   linux-arm/crypto/sha/sha256-armv4.S\
++#   linux-arm/crypto/sha/sha512-armv4.S\
++#   src/crypto/chacha/chacha_vec_arm.S\
++#   src/crypto/cpu-arm-asm.S\
++#   src/crypto/curve25519/asm/x25519-asm-arm.S\
++#   src/crypto/poly1305/poly1305_arm_asm.S\
+ 
+ linux_x86_sources := \
+   linux-x86/crypto/aes/aes-586.S\
+
+PATCH FOR IMAGEMAGICK
+
+diff --git a/Android.mk b/Android.mk
+index 5ab6699..4441417 100644
+--- a/Android.mk
++++ b/Android.mk
+@@ -52,6 +52,20 @@ LZMA_LIB_PATH                   := $(LOCAL_PATH)/xz-5.2.4
+ BZLIB_LIB_PATH                  := $(LOCAL_PATH)/bzip-1.0.8
+ LCMS_LIB_PATH                   := $(LOCAL_PATH)/liblcms2-2.9
+ 
++LIBBZ2_ENABLED        := true
++LIBFFTW_ENABLED       := true
++LIBFREETYPE2_ENABLED  := true
++LIBJPEG_TURBO_ENABLED := true
++LIBLZMA_ENABLED       := true
++LIBOPENJPEG_ENABLED   := true
++LIBPNG_ENABLED        := true
++LIBTIFF_ENABLED       := true
++LIBWEBP_ENABLED       := true
++LIBXML2_ENABLED       := true
++LIBZLIB_ENABLED       := true
++LIBLCMS2_ENABLED      := true
++BUILD_MAGICKWAND      := true
++
+ #-------------------------------------------------------------
+ # Include all modules
+ #-------------------------------------------------------------
+@@ -68,6 +82,9 @@ include $(MAKE_PATH)/libjpeg-turbo.mk
+ # libopenjpeg
+ include $(MAKE_PATH)/libopenjpeg.mk
+ 
++# libwebp
++include $(MAKE_PATH)/libwebp.mk
++
+ # libtiff
+ include $(MAKE_PATH)/libtiff.mk
+ 
+@@ -77,9 +94,6 @@ include $(MAKE_PATH)/libpng.mk
+ # libfreetype2
+ include $(MAKE_PATH)/libfreetype2.mk
+ 
+-# libwebp
+-include $(MAKE_PATH)/libwebp.mk
+-
+ # libfftw
+ include $(MAKE_PATH)/libfftw.mk
+ 
+diff --git a/libjpeg-turbo-2.0.2/jconfig.h b/libjpeg-turbo-2.0.2/jconfig.h
+index 47d14c9..5c6f8ee 100644
+--- a/libjpeg-turbo-2.0.2/jconfig.h
++++ b/libjpeg-turbo-2.0.2/jconfig.h
+@@ -1,57 +1,43 @@
+-/* autogenerated jconfig.h based on Android.mk var JCONFIG_FLAGS */ 
++/* autogenerated jconfig.h based on Android.mk var JCONFIG_FLAGS */
+ #ifndef JPEG_LIB_VERSION
+ #define JPEG_LIB_VERSION 62
+ #endif
+-
+ #ifndef LIBJPEG_TURBO_VERSION
+ #define LIBJPEG_TURBO_VERSION 2.0.2
+ #endif
+-
+ #ifndef LIBJPEG_TURBO_VERSION_NUMBER
+ #define LIBJPEG_TURBO_VERSION_NUMBER 202
+ #endif
+-
+ #ifndef C_ARITH_CODING_SUPPORTED
+ #define C_ARITH_CODING_SUPPORTED
+ #endif
+-
+ #ifndef D_ARITH_CODING_SUPPORTED
+ #define D_ARITH_CODING_SUPPORTED
+ #endif
+-
+ #ifndef MEM_SRCDST_SUPPORTED
+ #define MEM_SRCDST_SUPPORTED
+ #endif
+-
+ #ifndef WITH_SIMD
+ #define WITH_SIMD
+ #endif
+-
+ #ifndef BITS_IN_JSAMPLE
+ #define BITS_IN_JSAMPLE 8
+ #endif
+-
+ #ifndef HAVE_LOCALE_H
+ #define HAVE_LOCALE_H
+ #endif
+-
+ #ifndef HAVE_STDDEF_H
+ #define HAVE_STDDEF_H
+ #endif
+-
+ #ifndef HAVE_STDLIB_H
+ #define HAVE_STDLIB_H
+ #endif
+-
+ #ifndef NEED_SYS_TYPES_H
+ #define NEED_SYS_TYPES_H
+ #endif
+-
+ #ifndef HAVE_UNSIGNED_CHAR
+ #define HAVE_UNSIGNED_CHAR
+ #endif
+-
+ #ifndef HAVE_UNSIGNED_SHORT
+ #define HAVE_UNSIGNED_SHORT
+ #endif
+-
+diff --git a/libxml2-2.9.9/encoding.c b/libxml2-2.9.9/encoding.c
+index a3aaf10..60f165b 100644
+--- a/libxml2-2.9.9/encoding.c
++++ b/libxml2-2.9.9/encoding.c
+@@ -2394,7 +2394,6 @@ xmlCharEncOutput(xmlOutputBufferPtr output, int init)
+ {
+     int ret;
+     size_t written;
+-    size_t writtentot = 0;
+     size_t toconv;
+     int c_in;
+     int c_out;
+@@ -2451,7 +2450,6 @@ retry:
+                             xmlBufContent(in), &c_in);
+     xmlBufShrink(in, c_in);
+     xmlBufAddLen(out, c_out);
+-    writtentot += c_out;
+     if (ret == -1) {
+         if (c_out > 0) {
+             /* Can be a limitation of iconv or uconv */
+@@ -2536,7 +2534,6 @@ retry:
+ 	    }
+ 
+             xmlBufAddLen(out, c_out);
+-            writtentot += c_out;
+             goto retry;
+ 	}
+     }
+@@ -2567,9 +2564,7 @@ xmlCharEncOutFunc(xmlCharEncodingHandler *handler, xmlBufferPtr out,
+                   xmlBufferPtr in) {
+     int ret;
+     int written;
+-    int writtentot = 0;
+     int toconv;
+-    int output = 0;
+ 
+     if (handler == NULL) return(-1);
+     if (out == NULL) return(-1);
+@@ -2612,7 +2607,6 @@ retry:
+                             in->content, &toconv);
+     xmlBufferShrink(in, toconv);
+     out->use += written;
+-    writtentot += written;
+     out->content[out->use] = 0;
+     if (ret == -1) {
+         if (written > 0) {
+@@ -2622,8 +2616,6 @@ retry:
+         ret = -3;
+     }
+ 
+-    if (ret >= 0) output += ret;
+-
+     /*
+      * Attempt to handle error cases
+      */
+@@ -2700,7 +2692,6 @@ retry:
+ 	    }
+ 
+             out->use += written;
+-            writtentot += written;
+             out->content[out->use] = 0;
+             goto retry;
+ 	}
+diff --git a/libxml2-2.9.9/xpath.c b/libxml2-2.9.9/xpath.c
+index 5e3bb9f..505ec82 100644
+--- a/libxml2-2.9.9/xpath.c
++++ b/libxml2-2.9.9/xpath.c
+@@ -10547,7 +10547,7 @@ xmlXPathCompFilterExpr(xmlXPathParserContextPtr ctxt) {
+ 
+ static xmlChar *
+ xmlXPathScanName(xmlXPathParserContextPtr ctxt) {
+-    int len = 0, l;
++    int l;
+     int c;
+     const xmlChar *cur;
+     xmlChar *ret;
+@@ -10567,7 +10567,6 @@ xmlXPathScanName(xmlXPathParserContextPtr ctxt) {
+ 	    (c == '_') || (c == ':') ||
+ 	    (IS_COMBINING(c)) ||
+ 	    (IS_EXTENDER(c)))) {
+-	len += l;
+ 	NEXTL(l);
+ 	c = CUR_CHAR(l);
+     }
+diff --git a/make/libicu4c.mk b/make/libicu4c.mk
+index 21ec121..8b77865 100644
+--- a/make/libicu4c.mk
++++ b/make/libicu4c.mk
+@@ -250,7 +250,7 @@ LOCAL_MODULE    := libicuuc
+ LOCAL_SRC_FILES := $(src_files)
+ 
+ # when built in android, they require uconfig_local (because of android project), but we don't need this
+-$(shell > $(ICU_COMMON_PATH)/unicode/uconfig_local.h echo /* Autogenerated stub file to make libicuuc build happy */) \
++$(shell > $(ICU_COMMON_PATH)/unicode/uconfig_local.h echo /\* Autogenerated stub file to make libicuuc build happy \*/) \
+ 
+ ifeq ($(LIBXML2_ENABLED),true)
+     include $(BUILD_STATIC_LIBRARY)
+diff --git a/make/libjpeg-turbo.mk b/make/libjpeg-turbo.mk
+index d39dd41..fdebcf3 100644
+--- a/make/libjpeg-turbo.mk
++++ b/make/libjpeg-turbo.mk
+@@ -230,30 +230,30 @@ JCONFIG_FLAGS += \
+     HAVE_UNSIGNED_SHORT
+ 
+ JCONFIGINT_FLAGS += \
+-    BUILD="20190814" \
+-    PACKAGE_NAME="libjpeg-turbo" \
+-    VERSION="2.0.2"
++    BUILD=\"20190814\" \
++    PACKAGE_NAME=\"libjpeg-turbo\" \
++    VERSION=\"2.0.2\"
+ 
+ # originally defined in jconfigint.h, but the substitution has problems with spaces
+ LOCAL_CFLAGS := \
+     -DINLINE="inline __attribute__((always_inline))"
+ 
+ # create definition file jconfig.h, needed in order to build
+-$(shell echo /* autogenerated jconfig.h based on Android.mk var JCONFIG_FLAGS */ > $(JPEG_LIB_PATH)/jconfig.h)
++$(shell echo \/\* autogenerated jconfig.h based on Android.mk var JCONFIG_FLAGS \*\/ > $(JPEG_LIB_PATH)/jconfig.h)
+ $(foreach name,$(JCONFIG_FLAGS), \
+     $(if $(findstring =,$(name)), \
+-        $(shell >>$(JPEG_LIB_PATH)/jconfig.h echo #ifndef $(firstword $(subst =, ,$(name)))) \
++        $(shell >>$(JPEG_LIB_PATH)/jconfig.h echo \#ifndef $(firstword $(subst =, ,$(name)))) \
+     , \
+-        $(shell >>$(JPEG_LIB_PATH)/jconfig.h echo #ifndef $(name)) \
++        $(shell >>$(JPEG_LIB_PATH)/jconfig.h echo \#ifndef $(name)) \
+     ) \
+-    $(shell >>$(JPEG_LIB_PATH)/jconfig.h echo #define $(subst =, ,$(name))) \
+-    $(shell >>$(JPEG_LIB_PATH)/jconfig.h echo #endif) \
++    $(shell >>$(JPEG_LIB_PATH)/jconfig.h echo \#define $(subst =, ,$(name))) \
++    $(shell >>$(JPEG_LIB_PATH)/jconfig.h echo \#endif) \
+     $(shell >> $(JPEG_LIB_PATH)/jconfig.h echo.) \
+ )
+ 
+ # create definition file jconfigint.h, needed in order to build
+-$(shell >$(JPEG_LIB_PATH)/jconfigint.h echo /* autogenerated jconfigint.h based on Android.mk vars JCONFIGINT_FLAGS */)
+-$(foreach name,$(JCONFIGINT_FLAGS),$(shell >>$(JPEG_LIB_PATH)/jconfigint.h echo #define $(subst =, ,$(name))))
++$(shell >$(JPEG_LIB_PATH)/jconfigint.h echo /\* autogenerated jconfigint.h based on Android.mk vars JCONFIGINT_FLAGS \*/)
++$(foreach name,$(JCONFIGINT_FLAGS),$(shell >>$(JPEG_LIB_PATH)/jconfigint.h echo \#define $(subst =, ,$(name))))
+ 
+ ifeq ($(LIBJPEG_TURBO_ENABLED),true)
+     include $(BUILD_STATIC_LIBRARY)
+diff --git a/make/liblcms2.mk b/make/liblcms2.mk
+index e1fd3b9..29ca791 100644
+--- a/make/liblcms2.mk
++++ b/make/liblcms2.mk
+@@ -10,6 +10,10 @@ LOCAL_C_INCLUDES := \
+     $(LCMS_LIB_PATH)/include \
+     $(LCMS_LIB_PATH)/src
+ 
++LOCAL_EXPORT_C_INCLUDES := \
++    $(LCMS_LIB_PATH) \
++    $(LCMS_LIB_PATH)/include \
++    $(LCMS_LIB_PATH)/src
+ 
+ LOCAL_CFLAGS := \
+     -DHAVE_FUNC_ATTRIBUTE_VISIBILITY=1 \
+diff --git a/make/libmagick++-7.mk b/make/libmagick++-7.mk
+index 5352ccb..929396d 100644
+--- a/make/libmagick++-7.mk
++++ b/make/libmagick++-7.mk
+@@ -12,7 +12,7 @@ LOCAL_C_INCLUDES  :=  \
+ 
+ ifneq ($(STATIC_BUILD),true)
+     LOCAL_LDFLAGS += -fexceptions
+-    LOCAL_LDLIBS    := -L$(SYSROOT)/usr/lib -llog -lz
++    LOCAL_LDLIBS    := -llog -lz
+ endif
+ 
+ LOCAL_SRC_FILES := \
+diff --git a/make/libmagickcore-7.mk b/make/libmagickcore-7.mk
+index 81293b2..d51fced 100644
+--- a/make/libmagickcore-7.mk
++++ b/make/libmagickcore-7.mk
+@@ -25,6 +25,7 @@ else ifeq ($(TARGET_ARCH_ABI),x86_64)
+     
+ endif
+ 
++LOCAL_EXPORT_C_INCLUDES += $(IMAGE_MAGICK)
+ 
+ LOCAL_C_INCLUDES  += \
+     $(IMAGE_MAGICK) \
+@@ -45,10 +46,9 @@ LOCAL_C_INCLUDES  += \
+     $(BZLIB_LIB_PATH) \
+     $(LCMS_LIB_PATH)/include
+ 
+-
+ ifneq ($(STATIC_BUILD),true)
+ # ignored in static library builds
+-    LOCAL_LDLIBS    := -L$(SYSROOT)/usr/lib -llog -lz
++    LOCAL_LDLIBS    := -llog -lz
+ endif
+ 
+ 
+diff --git a/make/libmagickwand-7.mk b/make/libmagickwand-7.mk
+index 7be2fb6..0bbcca5 100644
+--- a/make/libmagickwand-7.mk
++++ b/make/libmagickwand-7.mk
+@@ -14,7 +14,7 @@ LOCAL_C_INCLUDES  :=  \
+ 
+ # always ignored in static builds
+ ifneq ($(STATIC_BUILD),true)
+-    LOCAL_LDLIBS    := -L$(SYSROOT)/usr/lib -llog -lz
++    LOCAL_LDLIBS    := -llog -lz
+ endif
+ 
+ LOCAL_SRC_FILES := \
+@@ -54,6 +54,29 @@ ifeq ($(OPENCL_BUILD),true)
+     LOCAL_SHARED_LIBRARIES += libopencl
+ endif
+ 
++LOCAL_SHARED_LIBRARIES += libstdc++
++
++ifeq ($(TARGET_ARCH_ABI),arm64-v8a)
++    LOCAL_EXPORT_C_INCLUDES += $(IMAGE_MAGICK)/configs/arm64
++    LOCAL_C_INCLUDES += $(IMAGE_MAGICK)/configs/arm64
++else ifeq ($(TARGET_ARCH_ABI),armeabi-v7a)  
++    LOCAL_EXPORT_C_INCLUDES += $(IMAGE_MAGICK)/configs/arm
++    LOCAL_C_INCLUDES += $(IMAGE_MAGICK)/configs/arm
++else ifeq ($(TARGET_ARCH_ABI),x86)
++    LOCAL_EXPORT_C_INCLUDES += $(IMAGE_MAGICK)/configs/x86
++    LOCAL_C_INCLUDES += $(IMAGE_MAGICK)/configs/x86
++else ifeq ($(TARGET_ARCH_ABI),x86_64)
++    LOCAL_EXPORT_C_INCLUDES += $(IMAGE_MAGICK)/configs/x86-64
++    LOCAL_C_INCLUDES += $(IMAGE_MAGICK)/configs/x86-64
++    
++    ifneq ($(STATIC_BUILD),true)
++        LOCAL_LDFLAGS += -latomic
++    endif
++    
++endif
++
++LOCAL_EXPORT_C_INCLUDES += $(IMAGE_MAGICK)
++
+ ifeq ($(BUILD_MAGICKWAND),true)
+     ifeq ($(STATIC_BUILD),true)
+         LOCAL_STATIC_LIBRARIES := \
+diff --git a/make/libpng.mk b/make/libpng.mk
+index 24fb8ac..dda05fd 100644
+--- a/make/libpng.mk
++++ b/make/libpng.mk
+@@ -30,6 +30,7 @@ ifeq ($(TARGET_ARCH_ABI), arm64-v8a)
+ endif # TARGET_ARCH_ABI == arm64-v8a
+ 
+ 
++LOCAL_EXPORT_C_INCLUDES := $(PNG_LIB_PATH)
+ LOCAL_C_INCLUDES := $(PNG_LIB_PATH)
+ 
+ LOCAL_SRC_FILES += \
+diff --git a/make/libtiff.mk b/make/libtiff.mk
+index ca43f25..2b17508 100644
+--- a/make/libtiff.mk
++++ b/make/libtiff.mk
+@@ -12,6 +12,9 @@ LOCAL_C_INCLUDES :=  \
+     $(LZMA_LIB_PATH)/liblzma/api \
+     $(WEBP_LIB_PATH)/src
+ 
++LOCAL_EXPORT_C_INCLUDES :=  \
++    $(TIFF_LIB_PATH)
++
+ ifeq ($(LIBLZMA_ENABLED),true)
+     LOCAL_CFLAGS += -DLZMA_SUPPORT=1
+ endif
+diff --git a/make/magick.mk b/make/magick.mk
+index 3ba4b1d..5471608 100644
+--- a/make/magick.mk
++++ b/make/magick.mk
+@@ -18,7 +18,7 @@ LOCAL_C_INCLUDES  :=  \
+     $(FREETYPE_LIB_PATH)/include
+ 
+ 
+-LOCAL_LDLIBS    := -L$(SYSROOT)/usr/lib -llog -lz
++LOCAL_LDLIBS    := -llog -lz
+ LOCAL_SRC_FILES := \
+     $(IMAGE_MAGICK)/utilities/magick.c \
+ 
+
+
+This file is part of GNU Emacs.
+
+GNU Emacs is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+GNU Emacs is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
diff --git a/java/README b/java/README
index fd4aa770f4b..9b6554481f6 100644
--- a/java/README
+++ b/java/README
@@ -1,6 +1,7 @@
 This directory holds the Java sources of the port of GNU Emacs to
 Android-like systems, along with files needed to create an application
-package out of them.
+package out of them.  If you need to build this port, please read the
+document ``INSTALL.android''.
 
 The ``org/gnu/emacs'' subdirectory contains the Java sources under the
 ``org.gnu.emacs'' package identifier.
diff --git a/src/coding.c b/src/coding.c
index 3ac4ada2939..fbf10188819 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -8513,34 +8513,31 @@ from_unicode (Lisp_Object str)
 Lisp_Object
 from_unicode_buffer (const wchar_t *wstr)
 {
-  if (sizeof (wchar_t) == 2)
-    {
-      /* We get one of the two final null bytes for free.  */
-      ptrdiff_t len = 1 + sizeof (wchar_t) * wcslen (wstr);
-      AUTO_STRING_WITH_LEN (str, (char *) wstr, len);
-      return from_unicode (str);
-    }
-  else
-    {
-      /* This code is used only on Android, where little endian UTF-16
-	 strings are extended to 32-bit wchar_t.  */
+#if defined WINDOWSNT || defined CYGWIN
+  /* We get one of the two final null bytes for free.  */
+  ptrdiff_t len = 1 + sizeof (wchar_t) * wcslen (wstr);
+  AUTO_STRING_WITH_LEN (str, (char *) wstr, len);
+  return from_unicode (str);
+#else
+  /* This code is used only on Android, where little endian UTF-16
+     strings are extended to 32-bit wchar_t.  */
 
-      uint16_t *words;
-      size_t length, i;
+  uint16_t *words;
+  size_t length, i;
 
-      length = wcslen (wstr) + 1;
+  length = wcslen (wstr) + 1;
 
-      USE_SAFE_ALLOCA;
-      SAFE_NALLOCA (words, sizeof *words, length);
+  USE_SAFE_ALLOCA;
+  SAFE_NALLOCA (words, sizeof *words, length);
 
-      for (i = 0; i < length - 1; ++i)
-	words[i] = wstr[i];
+  for (i = 0; i < length - 1; ++i)
+    words[i] = wstr[i];
 
-      words[i] = '\0';
-      AUTO_STRING_WITH_LEN (str, (char *) words,
-			    (length - 1) * sizeof *words);
-      return unbind_to (sa_count, from_unicode (str));
-    }
+  words[i] = '\0';
+  AUTO_STRING_WITH_LEN (str, (char *) words,
+			(length - 1) * sizeof *words);
+  return unbind_to (sa_count, from_unicode (str));
+#endif
 }
 
 wchar_t *