# Bisection visualization hint.. 7 messages from 2005-08-30 to 2005-08-30. Participants: Linus Torvalds, Junio C Hamano, A Large Angry SCM. Thread: https://gitlist.dev/t/1702 ## Linus Torvalds, 2005-08-30 17:29 Subject: Bisection visualization hint.. Message-ID: URL: https://gitlist.dev/e/Pine.LNX.4.58.0508301026450.4293%40g5.osdl.org ``` I'm testing bisection to find a bug that causes my G5 to no longer boot, and during the process have found this command line very nice: gitk bisect/bad --not $(cd .git/refs ; ls bisect/good-*) it basically shows the state of bisection with the known bad commit as the top, and cutting off all the good commits - so what you see are the potential buggy commits. But it's not the nicest of command lines and depends on knowing how bisection works, so maybe we could make git bisect visualize do this for us? Linus ``` ## Junio C Hamano, 2005-08-30 17:47 Subject: Re: Bisection visualization hint.. Message-ID: <7vhdd7joz6.fsf@assigned-by-dhcp.cox.net> URL: https://gitlist.dev/e/7vhdd7joz6.fsf%40assigned-by-dhcp.cox.net In-Reply-To: ``` Linus Torvalds writes: > I'm testing bisection to find a bug that causes my G5 to no longer boot, > and during the process have found this command line very nice: > > gitk bisect/bad --not $(cd .git/refs ; ls bisect/good-*) > > it basically shows the state of bisection with the known bad commit as the > top, and cutting off all the good commits - so what you see are the > potential buggy commits. > But it's not the nicest of command lines and depends on knowing how > bisection works, so maybe we could make > > git bisect visualize > > do this for us? Will do. Another thing that might make sense is roll it also into gitk, a new command from "File" menu to cause it to re-read not just ref values but the rev-list itself out of that particular rev-list command (and add any other common patterns as we discover them). ``` ## A Large Angry SCM, 2005-08-30 18:03 Subject: Re: Bisection visualization hint.. Message-ID: <43149F79.4020809@gmail.com> URL: https://gitlist.dev/e/43149F79.4020809%40gmail.com In-Reply-To: <7vhdd7joz6.fsf@assigned-by-dhcp.cox.net> ``` Junio C Hamano wrote: > Linus Torvalds writes: > >>I'm testing bisection to find a bug that causes my G5 to no longer boot, >>and during the process have found this command line very nice: >> >> gitk bisect/bad --not $(cd .git/refs ; ls bisect/good-*) >> >>it basically shows the state of bisection with the known bad commit as the >>top, and cutting off all the good commits - so what you see are the >>potential buggy commits. > >>But it's not the nicest of command lines and depends on knowing how >>bisection works, so maybe we could make >> >> git bisect visualize >> >>do this for us? > > Will do. > > Another thing that might make sense is roll it also into gitk, a > new command from "File" menu to cause it to re-read not just ref > values but the rev-list itself out of that particular rev-list > command (and add any other common patterns as we discover them). Unless gitk will always be part of git, this is better off as a gitk feature or gitk helper script. IE. it belongs in the gitk namespace, not the git namespace. That said, a wrapper for "git show-branch" (git show-bisect?) would be nice also. ``` ## Linus Torvalds, 2005-08-30 18:04 Subject: Fix bisection terminating condition Message-ID: URL: https://gitlist.dev/e/Pine.LNX.4.58.0508301038340.4426%40g5.osdl.org In-Reply-To: ``` When testing bisection and using gitk to visualize the result, it was obvious that the termination condition was broken. We know what the bad entry is only when the bisection ends up telling us to test the known-bad entry again. Also, add a safety net: if somebody marks as good something that includes the known-bad point, we now notice and complain, instead of writing an empty revision to the new bisection branch. Signed-off-by: Linus Torvalds --- diff --git a/git-bisect-script b/git-bisect-script --- a/git-bisect-script +++ b/git-bisect-script @@ -105,12 +105,16 @@ bisect_next() { good=$(git-rev-parse --sq --revs-only --not \ $(cd "$GIT_DIR" && ls refs/bisect/good-*)) && rev=$(eval "git-rev-list --bisect $good $bad") || exit - nr=$(eval "git-rev-list $rev $good" | wc -l) || exit - if [ "$nr" -le "1" ]; then + if [ -z "$rev" ]; then + echo "$bad was both good and bad" + exit 1 + fi + if [ "$rev" = "$bad" ]; then echo "$rev is first bad commit" git-diff-tree --pretty $rev exit 0 fi + nr=$(eval "git-rev-list $rev $good" | wc -l) || exit echo "Bisecting: $nr revisions left to test after this" echo "$rev" > "$GIT_DIR/refs/heads/new-bisect" git checkout new-bisect || exit ``` ## Linus Torvalds, 2005-08-30 18:17 Subject: Re: Bisection visualization hint.. Message-ID: URL: https://gitlist.dev/e/Pine.LNX.4.58.0508301116100.4237%40g5.osdl.org In-Reply-To: <43149F79.4020809@gmail.com> ``` On Tue, 30 Aug 2005, A Large Angry SCM wrote: > > Unless gitk will always be part of git, this is better off as a gitk > feature or gitk helper script. IE. it belongs in the gitk namespace, not > the git namespace. I really think that gitk is pretty fundamental. If for no other reason than the big fact that it helps people understand what is going on. That's why it's mentioned in the tutorial - people who have only used something broken like CVS will have a hard time visualizing what's going on, I suspect, but with gitk it all looks simple. Linus ``` ## Junio C Hamano, 2005-08-30 18:22 Subject: [PATCH] 'git bisect visualize' Message-ID: <7v64tnjndb.fsf@assigned-by-dhcp.cox.net> URL: https://gitlist.dev/e/7v64tnjndb.fsf%40assigned-by-dhcp.cox.net In-Reply-To: ``` Linus says: I'm testing bisection to find a bug that causes my G5 to no longer boot, and during the process have found this command line very nice: gitk bisect/bad --not $(cd .git/refs ; ls bisect/good-*) it basically shows the state of bisection with the known bad commit as the top, and cutting off all the good commits - so what you see are the potential buggy commits. Signed-off-by: Junio C Hamano --- * I think turning the flow inside out and driving bisect from gitk might make more sense, though. You start 'Bisect...' from the 'File' menu, click on one node and say 'good' or 'bad' from its pop-up menu,... git-bisect-script | 33 ++++++++++++++++++++++++++------- 1 files changed, 26 insertions(+), 7 deletions(-) 0e0713a470e7bea760aa0bd7510ddc668fb8b744 diff --git a/git-bisect-script b/git-bisect-script --- a/git-bisect-script +++ b/git-bisect-script @@ -2,12 +2,13 @@ . git-sh-setup-script || dir "Not a git archive" usage() { - echo >&2 'usage: git bisect [start | bad | good | next | reset] + echo >&2 'usage: git bisect [start|bad|good|next|reset|visualize] git bisect start reset bisect state and start bisection. git bisect bad [] mark a known-bad revision. git bisect good [...] mark ... known-good revisions. git bisect next find next bisection to test and check it out. -git bisect reset [] finish bisection search and go back to branch.' +git bisect reset [] finish bisection search and go back to branch. +git bisect visualize show the current state in gitk.' exit 1 } @@ -57,9 +58,15 @@ bisect_start() { bisect_bad() { bisect_autostart - case "$#" in 0 | 1) ;; *) usage ;; esac - rev=$(git-rev-parse --verify --default HEAD "$@") || exit - echo "$rev" > "$GIT_DIR/refs/bisect/bad" + case "$#" in + 0) + rev=$(git-rev-parse --verify HEAD) ;; + 1) + rev=$(git-rev-parse --verify "$1") ;; + *) + usage ;; + esac || exit + echo "$rev" >"$GIT_DIR/refs/bisect/bad" bisect_auto_next } @@ -67,10 +74,12 @@ bisect_good() { bisect_autostart case "$#" in 0) revs=$(git-rev-parse --verify HEAD) || exit ;; - *) revs=$(git-rev-parse --revs-only --no-flags "$@") || exit ;; + *) revs=$(git-rev-parse --revs-only --no-flags "$@") && + test '' != "$revs" || die "Bad rev: $@" ;; esac for rev in $revs do + rev=$(git-rev-parse --verify $rev) || exit echo "$rev" >"$GIT_DIR/refs/bisect/good-$rev" done bisect_auto_next @@ -107,8 +116,11 @@ bisect_next() { rev=$(eval "git-rev-list --bisect $good $bad") || exit nr=$(eval "git-rev-list $rev $good" | wc -l) || exit if [ "$nr" -le "1" ]; then + if [ "$rev" = "" ]; then + die "Your input does not make sense." + fi echo "$rev is first bad commit" - git-diff-tree --pretty $rev + git-diff-tree --pretty "$rev" exit 0 fi echo "Bisecting: $nr revisions left to test after this" @@ -118,6 +130,11 @@ bisect_next() { ln -sf refs/heads/bisect "$GIT_DIR/HEAD" } +bisect_visualize() { + bisect_next_check fail + gitk bisect/bad --not `cd "$GIT_DIR/refs" && echo bisect/good-*` +} + bisect_reset() { case "$#" in 0) branch=master ;; @@ -150,6 +167,8 @@ case "$#" in next) # Not sure we want "next" at the UI level anymore. bisect_next "$@" ;; + visualize) + bisect_visualize "$@" ;; reset) bisect_reset "$@" ;; *) ``` ## Junio C Hamano, 2005-08-30 18:56 Subject: Re: Fix bisection terminating condition Message-ID: <7vy86ji785.fsf@assigned-by-dhcp.cox.net> URL: https://gitlist.dev/e/7vy86ji785.fsf%40assigned-by-dhcp.cox.net In-Reply-To: ``` Linus Torvalds writes: > When testing bisection and using gitk to visualize the result, it was > obvious that the termination condition was broken. Thanks. ```