Improve RetroShare Android tools and documentation

build_scripts/Android/pull_sysroot.sh

@@ -0,0 +1,90 @@
+#!/bin/bash
+
+# Script to pull debugging sysroot from Android devices
+#
+# Copyright (C) 2020  Gioacchino Mazzurco <gio@eigenlab.org>
+# Copyright (C) 2020  Asociación Civil Altermundi <info@altermundi.net>
+#
+# This program is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the
+# Free Software Foundation, version 3.
+#
+# This program 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 Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <https://www.gnu.org/licenses/>
+
+<<"ASCIIDOC"
+
+Pull files from Android device to prepare a debugging sysroot
+Inspired by:
+https://fw4spl-org.github.io/fw4spl-blog/2015/07/27/Native-debugging-on-Android-with-QtCreator.html
+
+The goal is to have a local copy of the sysroot of the connected device.
+For that we use the command `adb pull <remote_dir_or_file> <local_dir_or_file>`
+
+We will get a copy of:
+
+- `/system/lib/`
+- `/vendor/lib/`
+- `libc.so`
+- `libcutils.so`
+
+As well as the binaries `linker` and `app_process`
+
+IMPORTANT:
+from one device to another, the remote file `app_process` can be a binary file
+or a symlink to a binary file - which is NOT ok for us.
+That's so we will try to pull every known possible variants of `app_process`,
+e.g. `app_process32` or `app_process_init`
+
+ASCIIDOC
+
+
+## Define default value for variable, take two arguments, $1 variable name,
+## $2 default variable value, if the variable is not already define define it
+## with default value.
+function define_default_value()
+{
+	VAR_NAME="${1}"
+	DEFAULT_VALUE="${2}"
+
+	[ -z "${!VAR_NAME}" ] && export ${VAR_NAME}="${DEFAULT_VALUE}"
+}
+
+define_default_value ANDROID_SERIAL "$(adb devices | head -n 2 | tail -n 1 | awk '{print $1}')"
+define_default_value DEBUG_SYSROOT "${HOME}/Builds/debug_sysroot/${ANDROID_SERIAL}/"
+
+rm -rf "${DEBUG_SYSROOT}"
+
+for mDir in  "/system/lib/" "/vendor/lib/"; do
+	mkdir -p "${DEBUG_SYSROOT}/${mDir}"
+	# adb pull doesn't behave like rsync dirA/ dirB/ so avoid nesting the
+	# directory by deleting last one before copying
+	rmdir "${DEBUG_SYSROOT}/${mDir}"
+	adb pull "${mDir}" "${DEBUG_SYSROOT}/${mDir}"
+done
+
+# Retrieve the specific binaries - some of these adb commands will fail, since
+# some files may not exist, but that's ok.
+
+mkdir -p "${DEBUG_SYSROOT}/system/bin/"
+for mBin in "/system/bin/linker" "/system/bin/app_process" \
+	"/system/bin/app_process_init" "/system/bin/app_process32" \
+	"/system/bin/app_process64" ; do
+	adb pull "${mBin}" "${DEBUG_SYSROOT}/${mBin}"
+done
+
+# Verify which variants of the specific binaries could be pulled 
+echo
+echo "Found the following specific binaries:"
+echo
+ls -1 "${DEBUG_SYSROOT}/system/bin/"*
+ls -1 "${DEBUG_SYSROOT}/system/lib/libc.so"*
+ls -1 "${DEBUG_SYSROOT}/system/lib/libcutils.so"*
+echo
+
+echo DEBUG_SYSROOT="${DEBUG_SYSROOT}"