trees: unified multi-tree configuration handling

the same function that loads configurations for single-tree
projects has been merged with the function for multi-tree
configs in git.sh, and that functionality has been removed
from git.sh; now it is all unified in the trees script.

as the saying goes: write one program to do one thing well.

the purpose of git.sh is to download source code, but not
to handle configuration files; the latter is meant to be
handled by the trees script, which then calls into git.sh
before running the build logic for that given project.

additionally: the "seen" files are no longer handled, at all.
the logic there was added ages ago, because at the time, i was
considering whether to separate configuration into a new
repository, so that users could more easily make their own
configuration, so it was a guard against misconfiguration.
however, that decision was canceled and we're always very
careful not to introduce a loop; if a loop does occur, the
worst that can possibly happen is you waste some CPU cycles.

Instead, print (on standard output) what config file is being
used, so the operator can see when an infinite loop occurs.

ALSO:

remove _setcfgarg in load_project_config()

it was used to skip when a target.cfg file didn't exist,
specifically on single-tree projects, but this is now
handled using -f instead, on the while loop inside that
function, so _setcfgarg is now a redundant variable.

Signed-off-by: Leah Rowe <leah@libreboot.org>

include/git.sh

@@ -2,42 +2,21 @@
 # Copyright (c) 2020-2021,2023-2024 Leah Rowe <leah@libreboot.org>
 # Copyright (c) 2022 Caleb La Grange <thonkpeasant@protonmail.com>
 
-eval `setvars "" _target rev loc url bkup_url depend tree_depend xtree mdir \
-    subhash subrepo subrepo_bkup subfile subfile_bkup`
+eval `setvars "" rev loc url bkup_url depend tree_depend xtree mdir subhash \
+    subrepo subrepo_bkup subfile subfile_bkup`
 
 fetch_targets()
 {
-	_target="$target"
 	[ ! -d "src/$project/$project" ] && x_ mkdir -p "src/$project" \
 	    && fetch_project "$project"
-	fetch_config
-	e "src/$project/$tree" d || prepare_new_tree; return 0
-}
-
-fetch_config()
-{
-	rm -f "$cfgsdir/"*/seen || $err "fetch_config $cfgsdir: !rm seen"
-	eval `setvars "" xtree tree_depend`
-	while true; do
-		eval `setvars "" rev tree`
-		load_target_config "$_target"
-		[ "$_target" = "$tree" ] && break
-		_target="$tree"
-	done
 	[ -n "$tree_depend" ] && [ "$tree_depend" != "$tree" ] && \
-		x_ ./update trees -f "$project" "$tree_depend"; return 0
-}
-
-load_target_config()
-{
-	[ -f "$cfgsdir/$1/seen" ] && $err "$project/$_target: tree loop"
-	eval `setcfg "$cfgsdir/$1/target.cfg"`
-	touch "$cfgsdir/$1/seen" || $err "load_config $cfgsdir/$1: !mk seen"
+		x_ ./update trees -f "$project" "$tree_depend"
+	e "src/$project/$tree" d || prepare_new_tree; return 0
 }
 
 prepare_new_tree()
 {
-	printf "Creating %s tree %s (%s)\n" "$project" "$tree" "$_target"
+	printf "Creating %s tree %s\n" "$project" "$tree"
 
 	git_prep "src/$project/$project" "src/$project/$project" \
 	    "$PWD/$cfgsdir/$tree/patches" "src/$project/$tree" "update"

script/trees

@@ -12,7 +12,7 @@ set -u -e
 cbmakeargs="UPDATED_SUBMODULES=1 CPUS=$XBMK_THREADS"
 eval `setvars "" xarch cdir config cmakedir xlang mode makeargs elfdir xtree \
     project target target_dir targets tree _f target1 bootstrapargs mkhelper \
-    autoconfargs config_name listfile autogenargs btype _cmd`
+    autoconfargs config_name listfile autogenargs btype cmd`
 
 main()
 {
@@ -46,8 +46,8 @@ main()
 
 	remkdir "${tmpgit%/*}"
 
-	_cmd="build_targets" && singletree "$project" && _cmd="build_project"
-	$_cmd $@
+	cmd="build_targets" && singletree "$project" && cmd="build_project"
+	$cmd $@
 
 	[ "$target1" = "utils" ] && [ "$project" = "coreboot" ] && return 0
 
@@ -57,7 +57,7 @@ main()
 
 build_project()
 {
-	load_project_config "$cfgsdir" 0 || return 0
+	load_project_config "$cfgsdir" || return 0
 	[ -f "$listfile" ] || listfile="" # optional on single-tree
 
 	dest_dir="$elfdir"
@@ -140,21 +140,29 @@ handle_src_tree()
 
 load_project_config()
 {
-	eval `setvars "" xarch xlang tree bootstrapargs autoconfargs xtree \
+	eval `setvars "" xarch xlang bootstrapargs autoconfargs xtree \
 	    tree_depend makeargs btype mkhelper`
 	[ -f "$1/target.cfg" ] || btype="auto"
 
-	# target.cfg optional on single-tree so return if missing.
-	# target.cfg mandatory on multi-tree so err if missing.
-	_setcfgarg="" && [ $# -gt 1 ] && _setcfgarg="$2"
-	if [ -f "$1/target.cfg" ] || [ -z "$_setcfgarg" ]; then
-		eval `setcfg "$1/target.cfg" $_setcfgarg`
-	fi
+	_tcfg="$1/target.cfg"
+	while [ -f "$_tcfg" ] || [ "$cmd" = "build_targets" ]; do
+		# target.cfg optional on single-tree so return if missing.
+		# target.cfg mandatory on multi-tree so err if missing.
+		eval `setvars "" rev tree`
+
+		printf "Loading %s config: %s\n" "$project" "$_tcfg"
+		eval `setcfg "$_tcfg"`
+		[ "$cmd" = "build_project" ] && break
+		[ "$mode" = "fetch" ] || break
+
+		[ "${_tcfg%/*/target.cfg}" = "${_tcfg%"/$tree/target.cfg"}" ] \
+		    && break; _tcfg="${_tcfg%/*/target.cfg}/$tree/target.cfg"
+	done
 
 	[ -z "$btype" ] || [ "${mode%config}" = "$mode" ] || return 1
 
 	[ "$mode" = "fetch" ] || return 0
-	[ -f "CHANGELOG" ] && return 1; fetch_${_cmd#build_}; return 1
+	[ -f "CHANGELOG" ] && return 1; fetch_${cmd#build_}; return 1
 }
 
 check_cross_compiler()