automake-wrapper: merge history

This is reconstructed from the CVS & git history from the automake &
automake-wrapper packages.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 186 insertions, 0 deletions

diff --git a/am-wrapper.sh b/am-wrapper.sh
new file mode 100755
index 0000000..2907626
--- /dev/null
+++ b/am-wrapper.sh
@@ -0,0 +1,186 @@
+#!/bin/sh
+# Copyright 1999-2018 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+
+# Executes the correct automake version.
+#
+# If WANT_AUTOMAKE is set (can be a whitespace delimited list of versions):
+#  - attempt to find an installed version using those
+#  - if magic keyword 'latest' is found, pick the latest version that exists
+#  - if nothing found, warn, and proceed as if WANT_AUTOMAKE was not set (below)
+# If WANT_AUTOMAKE is not set:
+#  - Try to detect the version of automake used to generate things (look at
+#    Makefile.in and aclocal.m4 and any other useful file)
+#  - If detected version is not found, warn and proceed as if blank slate
+#  - Try to locate the latest version of automake that exists and run it
+
+(set -o posix) 2>/dev/null && set -o posix
+
+_stderr() { printf 'am-wrapper: %s: %b\n' "${argv0}" "$*" 1>&2; }
+warn() { _stderr "warning: $*"; }
+err() { _stderr "error: $*"; exit 1; }
+unset IFS
+which() {
+	local p
+	IFS=: # we don't use IFS anywhere, so don't bother saving/restoring
+	for p in ${PATH} ; do
+		p="${p}/$1"
+		[ -e "${p}" ] && echo "${p}" && return 0
+	done
+	unset IFS
+	return 1
+}
+
+#
+# Sanitize argv[0] since it isn't always a full path #385201
+#
+argv0=${0##*/}
+case $0 in
+	${argv0})
+		# find it in PATH
+		if ! full_argv0=$(which "${argv0}") ; then
+			err "could not locate ${argv0}; file a bug"
+		fi
+		;;
+	*)
+		# re-use full/relative paths
+		full_argv0=$0
+		;;
+esac
+
+if ! seq 0 0 2>/dev/null 1>&2 ; then #338518
+	seq() {
+		local f l i
+		case $# in
+			1) f=1 i=1 l=$1;;
+			2) f=$1 i=1 l=$2;;
+			3) f=$1 i=$2 l=$3;;
+		esac
+		while :; do
+			[ $l -lt $f -a $i -gt 0 ] && break
+			[ $f -lt $l -a $i -lt 0 ] && break
+			echo $f
+			: $(( f += i ))
+		done
+		return 0
+	}
+fi
+
+#
+# Set up bindings between actual version and WANT_AUTOMAKE;
+# Start with last known versions to speed up lookup process.
+#
+LAST_KNOWN_AUTOMAKE_VER="16"
+vers=$(printf '1.%s ' `seq ${LAST_KNOWN_AUTOMAKE_VER} -1 4`)
+
+#
+# Helper to scan for a usable program based on version.
+#
+binary=
+all_vers=
+find_binary() {
+	local v
+	all_vers="${all_vers} $*" # For error messages.
+	for v ; do
+		if [ -x "${full_argv0}-${v}" ] ; then
+			binary="${full_argv0}-${v}"
+			binary_ver=${v}
+			return 0
+		fi
+	done
+	return 1
+}
+
+#
+# Try and find a usable automake version.  First check the WANT_AUTOMAKE
+# setting (whitespace delimited list), then fallback to the latest.
+#
+find_latest() {
+	if ! find_binary ${vers} ; then
+		# Brute force it.
+		find_binary $(printf '1.%s ' `seq 99 -1 ${LAST_KNOWN_AUTOMAKE_VER}`)
+	fi
+}
+for wx in ${WANT_AUTOMAKE:-latest} ; do
+	if [ "${wx}" = "latest" ] ; then
+		find_latest && break
+	else
+		find_binary ${wx} && break
+	fi
+done
+
+if [ -z "${binary}" ] && [ -n "${WANT_AUTOMAKE}" ] ; then
+	warn "could not locate installed version for WANT_AUTOMAKE='${WANT_AUTOMAKE}'; ignoring"
+	unset WANT_AUTOMAKE
+	find_latest
+fi
+
+if [ -z "${binary}" ] ; then
+	err "Unable to locate any usuable version of automake.\n" \
+	    "\tI tried these versions:${all_vers}\n" \
+	    "\tWith a base name of '${full_argv0}'."
+fi
+
+#
+# autodetect helpers
+#
+do_awk() {
+	local file=$1 ; shift
+	local v=$(awk -v regex="$*" '{
+		if (ret = match($0, regex)) {
+			s = substr($0, ret, RLENGTH)
+			ret = match(s, "[0-9]\\.[0-9]+")
+			print substr(s, ret, RLENGTH)
+			exit
+		}
+		}' "${file}")
+	case " ${auto_vers} " in
+	*" ${v} "*) ;;
+	*) auto_vers="${auto_vers:+${auto_vers} }${v}" ;;
+	esac
+}
+
+#
+# autodetect routine
+#
+if [ -z "${WANT_AUTOMAKE}" ] ; then
+	auto_vers=
+	if [ -r "Makefile.in" ] ; then
+		do_awk Makefile.in '^# Makefile.in generated (automatically )?by automake [0-9]\\.[0-9]+'
+	fi
+	if [ -r "aclocal.m4" ] ; then
+		do_awk aclocal.m4 'generated automatically by aclocal [0-9]\\.[0-9]+'
+		do_awk aclocal.m4 '[[:space:]]*\\[?AM_AUTOMAKE_VERSION\\(\\[?[0-9]\\.[0-9]+[^)]*\\]?\\)'
+	fi
+	# We don't need to set $binary here as it has already been setup for us
+	# earlier to the latest available version.
+	if [ -n "${auto_vers}" ] ; then
+		if ! find_binary ${auto_vers} ; then
+			warn "auto-detected versions not found (${auto_vers}); falling back to latest available"
+		fi
+	fi
+fi
+
+if [ -n "${WANT_AMWRAPPER_DEBUG}" ] ; then
+	if [ -n "${WANT_AUTOMAKE}" ] ; then
+		warn "DEBUG: WANT_AUTOMAKE is set to ${WANT_AUTOMAKE}"
+	fi
+	warn "DEBUG: will execute <${binary}>"
+fi
+
+#
+# for further consistency
+#
+export WANT_AUTOMAKE="${binary_ver}"
+
+#
+# Now try to run the binary
+#
+if [ ! -x "${binary}" ] ; then
+	# this shouldn't happen
+	err "${binary} is missing or not executable.\n" \
+	    "\tPlease try installing the correct version of automake."
+fi
+
+exec "${binary}" "$@"
+# The shell will error out if `exec` failed.