revamp loop feature

now CBT and builds pass their file names to the current build
via the context. The build then simply blocks until any file changes.
Then it returns with a special exit code, which the bash script picks
up and restarts CBT. Thats works well for looping over project files.
It works less well for looping over builds and CBT itself. For this
a build has to success once, so that the .cbt-loop.tmp file exists.
Then looping works for cbt and builds, but the file list is not
updated in case of compile errors, etc.

Fixes
- https://github.com/cvogt/cbt/issues/406
- https://github.com/cvogt/cbt/issues/405
- https://github.com/cvogt/cbt/issues/202
- https://github.com/cvogt/cbt/issues/50
- https://github.com/cvogt/cbt/issues/22

We should improve for 1.0 in https://github.com/cvogt/cbt/issues/419
to handle looping over build files and cbt itself smarter.

1 files changed, 38 insertions, 2 deletions

diff --git a/cbt b/cbt
index 3a856ec..1f3d581 100755
--- a/cbt
+++ b/cbt
@@ -199,6 +199,7 @@ stage1 () {
 			log "Running JVM directly" "$@"
 			# JVM options to improve startup time. See https://github.com/cvogt/cbt/pull/262
 			java $JAVA_OPTS $DEBUG -Xmx6072m -Xss10M -XX:MaxJavaStackTraceDepth=-1 -XX:+TieredCompilation -XX:TieredStopAtLevel=1 -Xverify:none -cp $NAILGUN$TARGET cbt.NailgunLauncher $(time_taken) "$CWD" "$@"
+			exitCode=$?
 		else
 			log "Running via background process (nailgun)" "$@"
 			for i in 0 1 2 3 4 5 6 7 8 9; do
@@ -222,17 +223,52 @@ stage1 () {
 			done
 			log "Running CBT via Nailgun." "$@"
 			$NG cbt.NailgunLauncher $(time_taken) "$CWD" "$@"
+			exitCode=$?
 		fi
-		exitCode=$?
 		log "Done running CBT." "$@"
 	fi
 }
 
+
+loop=1
+case "$1" in
+	"loop") loop=0
+esac
+case "$2" in
+	"loop") loop=0
+esac
+
+CBT_SIGNALS_LOOPING=253
+USER_PRESSED_CTRL_C=130
+
+CBT_LOOP_FILE="$CWD/target/.cbt-loop.tmp"
 while true; do
 	stage1 "$@"
-	if [ ! "$1" = "loop" ]; then
+	if [ ! $loop -eq 0 ] || [ $exitCode -eq $USER_PRESSED_CTRL_C ]; then
+		log "not looping, exiting" "$@"
 		break
+	else
+		if [ ! $exitCode -eq $CBT_SIGNALS_LOOPING ]; then
+			log "exitCode $exitCode" "$@"
+			which fswatch >/dev/null 2>/dev/null
+			export fswatch_installed=$?
+			if [ -f "$CBT_LOOP_FILE" ]; then
+				if [ $fswatch_installed -eq 0 ]; then
+					# fswatch allows looping over CBT's sources itself
+					log "fswatch found. looping." "$@"
+					files=($(cat "$CBT_LOOP_FILE"))
+					fswatch --one-event "${files[@]}"
+				else
+					log "fswatch not installed, stopping cbt" "$@"
+					break
+				fi
+			else
+				log "no $CBT_LOOP_FILE file, stopping cbt" "$@"
+				break
+			fi
+		fi
 	fi
+
 	echo "======= Restarting CBT =======" 1>&2
 done