Script to set up android build directory

Test: manual
Change-Id: I93aa3aa9745330ec21385ce12cc586aeaa803e12

scripts/setup-android-build.sh

@@ -0,0 +1,93 @@
+#! /bin/bash
+#
+# Sets the current directory as Android build output directory for a
+# given target by writing the "prefix script" to it. Commands prefixed
+# by this script are executed in the Android build environment. E.g.,
+# running
+#   ./run <command>
+# runs <command> as if we issued
+#   cd <source>
+#   mount --bind <build dir> out
+#   . build/envsetup.sh
+#   lunch <config>
+#   <command>
+#   exit
+#
+# This arrangement eliminates the need to issue envsetup/lunch commands
+# manually, and allows to run multiple builds from the same shell.
+# Thus, if your source tree is in ~/aosp and you are building for
+# 'blueline' and 'cuttlefish', issuing
+#   cd /sdx/blueline && \
+#      ~/aosp/build/soong/scripts/setup-android-build.sh aosp_blueline-userdebug
+#   cd /sdx/cuttlefish && \
+#      ~/aosp/build/soong/scripts/setup-android-build.sh aosp_cf_arm64_phone-userdebug
+# sets up build directories in /sdx/blueline and /sdx/cuttlefish respectively.
+# After that, issue
+#   /sdx/blueline/run m
+# to build blueline image, and issue
+#   /sdx/cuttlefish atest CtsSecurityBulletinHostTestCases
+# to run CTS tests. Notice there is no need to change to a specific directory for that.
+#
+# Argument:
+# * configuration (one of those shown by `lunch` command).
+#
+set -e
+function die() { printf "$@"; exit 1; }
+
+# Find out where the source tree using the fact that we are in its
+# build/ subdirectory.
+[[ "$(uname)" == Linux ]] || die "This setup runs only on Linux\n"
+declare -r mydir="${0%/*}"
+declare -r source="${mydir%/build/soong/scripts}"
+[[ "/${mydir}/" =~ '/build/soong/scripts/' ]] || \
+  die "$0 should be in build/soong/scripts/ subdirectory of the source tree\n"
+[[ ! -e .repo && ! -e .git ]] || \
+  die "Current directory looks like source. You should be in the _target_ directory.\n"
+# Do not override old run script.
+if [[ -x ./run ]]; then
+  # Set variables from config=xxx and source=xxx comments in the existing script.
+  . <(sed -nr 's/^# *source=(.*)/oldsource=\1/p;s/^# *config=(.*)/oldconfig=\1/p' run)
+  die "This directory has been already set up to build Android for %s from %s.\n\
+Remove 'run' file if you want to set it up afresh\n" "$oldconfig" "$oldsource"
+fi
+
+(($#<2)) || die "usage: %s [<config>]\n" $0
+
+if (($#==1)); then
+  # Configuration is provided, emit run script.
+  declare -r config="$1"
+  declare -r target="$PWD"
+  cat >./run <<EOF
+#! /bin/bash
+# source=$source
+# config=$config
+declare -r cmd=\$(printf ' %q' "\$@")
+"$source/prebuilts/build-tools/linux-x86/bin/nsjail"\
+ -Mo -q -e -t 0\
+ -EANDROID_QUIET_BUILD=true \
+ -B / -B "$target:$source/out"\
+ --cwd "$source"\
+ --skip_setsid \
+ --keep_caps\
+ --disable_clone_newcgroup\
+ --disable_clone_newnet\
+ --rlimit_as soft\
+ --rlimit_core soft\
+ --rlimit_cpu soft\
+ --rlimit_fsize soft\
+ --rlimit_nofile soft\
+ --proc_rw\
+ --hostname $(hostname) \
+ --\
+ /bin/bash -i -c ". build/envsetup.sh && lunch "$config" &&\$cmd"
+EOF
+  chmod +x ./run
+else
+  # No configuration, show available ones.
+  printf "Please specify build target. Common values:\n"
+  (cd "$source"
+   . build/envsetup.sh
+   get_build_var COMMON_LUNCH_CHOICES | tr ' ' '\n' | pr -c4 -tT -W"$(tput cols)"
+  )
+  exit 1
+fi