Add support for Android Emacs using Termux

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"))

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 "$MSYSTEM" ] || ! [ -r "/etc/profile" ]; then
@@ -511,6 +531,7 @@ os_argument() {
         void)    os_void    "$@";;
         opensuse) os_opensuse "$@";;
         alpine)  os_alpine  "$@";;
+        android) os_android  "$@";;
         *)       echo "Invalid --os argument: $OS"
                  exit 1
     esac || {
@@ -541,6 +562,7 @@ os_nixos    "$@" || \
 os_void     "$@" || \
 os_opensuse "$@" || \
 os_alpine   "$@" || \
+os_android  "$@" || \
 {
     OS_IS_HANDLED=
     if [ -z "$DRY_RUN" ]; then

server/autobuild.android

@@ -0,0 +1,2 @@
+#!/bin/sh
+sh autobuild $@