Add support for Android Emacs using Termux

Notes from the original PR:

The dependencies for android in autobuild can not be installed in
pdf-tools-install, they have to be installed manually in Termux. But
the dependencies are checked when running autobuild.

pdf-tools-install successfully installs epdfinfo in Android Emacs. One
can then view pdf files.

The shebang in autobuild does not work in Termux, I therefore had to
create a separate script "autobuild.android" that in turn executes
autobuild. The problem with the shebang is that "env" in Termux is not
located at "/usr/bin/env".

pdf-tools/Makefile does currently not work in Android Emacs, but it is
not needed for running pdf-tools-install. Fixing this will have to be
done in a separate pull request, if deemed necessary. Reason: There is
yet no consensus for how to implement a command line emacs, to be run
in batch mode, in Android Emacs.

I have successfully run "make test" in Ubuntu, in the repo feature
branch. Running "make server-test" in the master branch fails, so I
have not tested this in the feature branch.

Closes: #230
Author: @johanwiden

3 files changed, 25 insertions, 1 deletions

diff --git a/lisp/pdf-tools.el b/lisp/pdf-tools.el
index 670792c..e36f966 100644
--- a/lisp/pdf-tools.el
+++ b/lisp/pdf-tools.el
@@ -323,7 +323,7 @@ Returns the buffer of the compilation process."
          (process-environment process-environment)
          (default-directory build-directory)
          (autobuild (shell-quote-argument
-                     (expand-file-name "autobuild" build-directory)))
+                     (expand-file-name (if (eq system-type 'android) "autobuild.android" "autobuild") build-directory)))
          (msys2-p (equal "bash.exe" (file-name-nondirectory shell-file-name))))
     (unless shell-file-name
       (error "No suitable shell found"))
diff --git a/server/autobuild b/server/autobuild
index 1d76820..3201a00 100755
--- a/server/autobuild
+++ b/server/autobuild
@@ -306,6 +306,26 @@ os_debian() {
     return 0
 }
 
+# Android using Termux
+os_android() {
+    if ! [ -d "/data/data/com.termux/files/home" ]; then
+        return 1
+    fi
+    PACKAGES="autoconf
+              automake
+              binutils
+              clang
+              libpng
+              poppler
+              zlib
+              make
+              xorgproto
+              pkg-config"
+    PKGCMD=pkg
+    PKGARGS="install"
+    return 0
+}
+
 # Msys2
 os_msys2() {
     if [ -z "$MSYSTEM" ] || ! [ -r "/etc/profile" ]; then
@@ -546,6 +566,7 @@ os_argument() {
         opensuse) os_opensuse "$@";;
         alpine)  os_alpine  "$@";;
         nobara)  os_nobara  "$@";;
+        android) os_android  "$@";;
         *)       echo "Invalid --os argument: $OS"
                  exit 1
     esac || {
@@ -577,6 +598,7 @@ os_void     "$@" || \
 os_opensuse "$@" || \
 os_alpine   "$@" || \
 os_nobara   "$@" || \
+os_android  "$@" || \
 {
     OS_IS_HANDLED=
     if [ -z "$DRY_RUN" ]; then
diff --git a/server/autobuild.android b/server/autobuild.android
new file mode 100755
index 0000000..4fc076f
--- /dev/null
+++ b/server/autobuild.android
@@ -0,0 +1,2 @@
+#!/bin/sh
+sh autobuild "$@"