Pull request: all: imp scripts

Merge in DNS/adguard-home from imp-sh to master

Squashed commit of the following:

commit 477832e11eca2ef7ac0071b5da938dacb2ed617d
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed May 19 20:24:34 2021 +0300

    scripts: rm dbg

commit dbb4b8c783f607781b980dcd57d78085c9022e72
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed May 19 20:21:20 2021 +0300

    all: imp code, compat, docs

commit e6e4375d67ad1c213efb04411e3ba0bc6293f936
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed May 19 19:33:48 2021 +0300

    all: imp scripts

scripts/make/go-build.sh

@@ -2,41 +2,47 @@
 
 # AdGuard Home Build Script
 #
-# The commentary in this file is written with the assumption that the
-# reader only has superficial knowledge of the POSIX shell language and
-# alike.  Experienced readers may find it overly verbose.
+# The commentary in this file is written with the assumption that the reader
+# only has superficial knowledge of the POSIX shell language and alike.
+# Experienced readers may find it overly verbose.
+
+# The default verbosity level is 0.  Show every command that is run and every
+# package that is processed if the caller requested verbosity level greater than
+# 0.  Also show subcommands if the requested verbosity level is greater than 1.
+# Otherwise, do nothing.
+verbose="${VERBOSE:-0}"
+readonly verbose
 
-# The default verbosity level is 0.  Show every command that is run and
-# every package that is processed if the caller requested verbosity
-# level greater than 0.  Also show subcommands if the requested
-# verbosity level is greater than 1.  Otherwise, do nothing.
-readonly verbose="${VERBOSE:-0}"
 if [ "$verbose" -gt '1' ]
 then
 	env
 	set -x
-	readonly v_flags='-v'
-	readonly x_flags='-x'
+	v_flags='-v'
+	x_flags='-x'
 elif [ "$verbose" -gt '0' ]
 then
 	set -x
-	readonly v_flags='-v'
-	readonly x_flags=''
+	v_flags='-v'
+	x_flags=''
 else
 	set +x
-	readonly v_flags=''
-	readonly x_flags=''
+	v_flags=''
+	x_flags=''
 fi
+readonly x_flags v_flags
 
 # Exit the script if a pipeline fails (-e), prevent accidental filename
 # expansion (-f), and consider undefined variables as errors (-u).
 set -e -f -u
 
 # Allow users to set the Go version.
-readonly go="${GO:-go}"
+go="${GO:-go}"
+readonly go
 
 # Require the channel to be set and validate the value.
-readonly channel="$CHANNEL"
+channel="$CHANNEL"
+readonly channel
+
 case "$channel"
 in
 ('development'|'edge'|'beta'|'release')
@@ -52,15 +58,19 @@ esac
 # Require the version to be set.
 #
 # TODO(a.garipov): Additional validation?
-readonly version="$VERSION"
+version="$VERSION"
+readonly version
 
 # Set date and time of the current build unless already set.
-readonly buildtime="${BUILD_TIME:-$( date -u +%FT%TZ%z )}"
+buildtime="${BUILD_TIME:-$( date -u +%FT%TZ%z )}"
+readonly buildtime
+
+# Set the linker flags accordingly: set the release channel and the current
+# version as well as goarm and gomips variable values, if the variables are set
+# and are not empty.
+version_pkg='github.com/AdguardTeam/AdGuardHome/internal/version'
+readonly version_pkg
 
-# Set the linker flags accordingly: set the release channel and the
-# current version as well as goarm and gomips variable values, if the
-# variables are set and are not empty.
-readonly version_pkg='github.com/AdguardTeam/AdGuardHome/internal/version'
 ldflags="-s -w"
 ldflags="${ldflags} -X ${version_pkg}.version=${version}"
 ldflags="${ldflags} -X ${version_pkg}.channel=${channel}"
@@ -74,39 +84,47 @@ then
 fi
 
 # Allow users to limit the build's parallelism.
-readonly parallelism="${PARALLELISM:-}"
-if [ "$parallelism" != '' ]
+parallelism="${PARALLELISM:-}"
+readonly parallelism
+
+if [ "${parallelism}" != '' ]
 then
-	readonly par_flags="-p ${parallelism}"
+	par_flags="-p ${parallelism}"
 else
-	readonly par_flags=''
+	par_flags=''
 fi
+readonly par_flags
 
 # Allow users to specify a different output name.
-readonly out="${OUT:-}"
+out="${OUT:-}"
+readonly out
+
 if [ "$out" != '' ]
 then
-	readonly out_flags="-o ${out}"
+	out_flags="-o ${out}"
 else
-	readonly out_flags=''
+	out_flags=''
 fi
+readonly out_flags
 
-# Allow users to enable the race detector.  Unfortunately, that means
-# that CGo must be enabled.
-readonly race="${RACE:-0}"
-if [ "$race" = '0' ]
+# Allow users to enable the race detector.  Unfortunately, that means that cgo
+# must be enabled.
+if [ "${RACE:-0}" -eq '0' ]
 then
-	readonly cgo_enabled='0'
-	readonly race_flags=''
+	cgo_enabled='0'
+	race_flags=''
 else
-	readonly cgo_enabled='1'
-	readonly race_flags='--race'
+	cgo_enabled='1'
+	race_flags='--race'
 fi
+readonly cgo_enabled race_flags
 
-export CGO_ENABLED="$cgo_enabled"
-export GO111MODULE='on'
+CGO_ENABLED="$cgo_enabled"
+GO111MODULE='on'
+export CGO_ENABLED GO111MODULE
 
-readonly build_flags="${BUILD_FLAGS:-$race_flags --trimpath $out_flags $par_flags $v_flags $x_flags}"
+build_flags="${BUILD_FLAGS:-$race_flags --trimpath $out_flags $par_flags $v_flags $x_flags}"
+readonly build_flags
 
 # Don't use quotes with flag variables to get word splitting.
 "$go" generate $v_flags $x_flags ./main.go