From fb5275938d911e757d35c5084f299c039e238cd9 Mon Sep 17 00:00:00 2001
From: Avery Pennarun <apenwarr@gmail.com>
Date: Sat, 1 Jan 2011 03:42:35 -0800
Subject: [PATCH] minimal/do: use ".did" stamp files instead of empty target
 files.

If all.do runs and creates no output, we shouldn't create a file called
'all', but we should remember that 'all' has been run successfully.  We do
this by creating 'all.did' during the build.

Since minimal/do always just wipes everything out every time it runs, we can
safely remove the .did files after minimal/do terminates, so this doesn't
clutter things too much in normal use.

This fixes some edge cases, particularly that 'minimal/do clean' no longer
leaves stupid files named "clean" lying around, and the redo-sh directory
can now be rebuilt correctly since we rebuild it as long as redo-sh.did
doesn't exist.  (We don't want to "rm -rf redo-sh" because it makes me
nervous.)
---
 clean.do   |  2 +-
 minimal/do | 20 +++++++++++++++-----
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/clean.do b/clean.do
index ec75b2a..938703b 100644
--- a/clean.do
+++ b/clean.do
@@ -1,3 +1,4 @@
+rm -rf t/.redo redo-sh
 if [ -e .do_built ]; then
 	while read x; do
 		rm -f "$x"
@@ -6,5 +7,4 @@ fi
 [ -z "$DO_BUILT" ] && rm -rf .do_built .do_built.dir
 redo t/clean Documentation/clean
 rm -f *~ .*~ */*~ */.*~ *.pyc install.wrapper
-rm -rf t/.redo redo-sh
 find . -name '*.tmp' -exec rm -fv {} \;
diff --git a/minimal/do b/minimal/do
index 9120704..44045ef 100755
--- a/minimal/do
+++ b/minimal/do
@@ -15,12 +15,14 @@ _dirsplit()
 _dirsplit "$0"
 export REDO=$(cd "${dir:-.}" && echo "$PWD/$base")
 
+DO_TOP=
 if [ -z "$DO_BUILT" ]; then
+	DO_TOP=1
 	export DO_BUILT=$PWD/.do_built
 	if [ -e "$DO_BUILT" ]; then
 		echo "Removing previously built files..." >&2
 		sort -u "$DO_BUILT" | tee "$DO_BUILT.new" |
-		while read f; do rm -f "$f" 2>/dev/null; done
+		while read f; do rm -f "$f" "$f.did" 2>/dev/null; done
 		mv "$DO_BUILT.new" "$DO_BUILT"
 	fi
 	DO_PATH=$DO_BUILT.dir
@@ -55,7 +57,7 @@ _run_dofile()
 	export DO_DEPTH="$DO_DEPTH  "
 	export REDO_TARGET=$PWD/$TARGET
 	set -e
-	. "$PWD/$DOFILE" >"$TARGET.tmp"
+	. "$PWD/$DOFILE" >"$TARGET.tmp2"
 }
 
 
@@ -63,7 +65,7 @@ _do()
 {
 	DIR=$1
 	TARGET=$2
-	if [ ! -e "$TARGET" ]; then
+	if [ ! -e "$TARGET" ] || [ -e "$TARGET/." -a ! -e "$TARGET.did" ]; then
 		printf '\033[32mdo  %s\033[1m%s\033[m\n' \
 			"$DO_DEPTH" "$DIR$TARGET" >&2
 		echo "$PWD/$TARGET" >>"$DO_BUILT"
@@ -75,6 +77,7 @@ _do()
 			echo "do: $TARGET: no .do file" >&2
 			return 1
 		fi
+		: >>"$TARGET.did"
 		( _run_dofile "$BASE" "$EXT" "$TARGET.tmp" )
 		RV=$?
 		if [ $RV != 0 ]; then
@@ -82,8 +85,10 @@ _do()
 				"$DIR$TARGET: got exit code $RV" >&2
 			return $RV
 		fi
-		mv "$TARGET.tmp" "$TARGET" 2>/dev/null
-		: >>"$TARGET"
+		mv "$TARGET.tmp" "$TARGET" 2>/dev/null ||
+		! test -s "$TARGET.tmp2" ||
+		mv "$TARGET.tmp2" "$TARGET" 2>/dev/null
+		rm -f "$TARGET.tmp2"
 	else
 		echo "do  $DO_DEPTH$TARGET exists." >&2
 	fi
@@ -105,3 +110,8 @@ if [ -n "$*" ]; then
 else
 	redo all
 fi
+
+if [ -n "$DO_TOP" ]; then
+	echo "Removing stamp files..." >&2
+	while read f; do rm -f "$f.did" 2>/dev/null; done <"$DO_BUILT"
+fi