tcwg_kernel-bisect.sh: Send emails with useful info when bisect fails

We are trying to reduce the number of failed bisect and make
scripting more robust against history re-writes (which is the
primary cause of failed bisects).  Re-work logic to generate
email body to include useful info about failed bisects.

Change-Id: Ia25f3311016c0175f3b59e1e4c7308485b5276a4

1 files changed, 57 insertions, 33 deletions

diff --git a/tcwg_kernel-bisect.sh b/tcwg_kernel-bisect.sh
index 22566aab..71d80753 100755
--- a/tcwg_kernel-bisect.sh
+++ b/tcwg_kernel-bisect.sh
@@ -201,8 +201,25 @@ current_rev=$first_bad
 reset_baseline=true
 EOF
 
-if [ -f artifacts/first-bad ]; then
-    first_bad=$(cat artifacts/first-bad)
+# Trigger master build now instead of waiting for next timed SCM trigger.
+cat > $artifacts/trigger-2-build-master <<EOF
+current_project=$current_project
+EOF
+
+# Email developers.
+CI_MAIL_RECIPIENTS="tcwg-validation@linaro.org"
+case "$toolchain:$current_project" in
+    gnu:*) CI_MAIL_RECIPIENTS="$CI_MAIL_RECIPIENTS, christophe.lyon@linaro.org, maxim.kuvyrkov@linaro.org" ;;
+    llvm:linux) CI_MAIL_RECIPIENTS="$CI_MAIL_RECIPIENTS, arnd@linaro.org, mark.brown@linaro.org, ndesaulniers@google.com, trong@google.com" ;;
+    llvm:llvm) CI_MAIL_RECIPIENTS="$CI_MAIL_RECIPIENTS, adhemerval.zanella@linaro.org, maxim.kuvyrkov@linaro.org, ndesaulniers@google.com, trong@google.com, yvan.roux@linaro.org" ;;
+esac
+
+cat > $artifacts/ci_mail_parameters.sh <<EOF
+CI_MAIL_RECIPIENTS="$CI_MAIL_RECIPIENTS"
+EOF
+chmod +x $artifacts/ci_mail_parameters.sh
+
+if [ -f $artifacts/first-bad ]; then
     touch build-name
     sed -i -e "s/\$/-$first_bad/" build-name
 
@@ -221,16 +238,11 @@ if [ -f artifacts/first-bad ]; then
 	ln -s "build-$last_good-last_good" "$artifacts/build-$last_good-baseline"
     fi
 
-    # Email developers on successful bisects.
-    CI_MAIL_RECIPIENTS="tcwg-validation@linaro.org"
-    case "$toolchain:$current_project" in
-        gnu:*) CI_MAIL_RECIPIENTS="$CI_MAIL_RECIPIENTS, christophe.lyon@linaro.org, maxim.kuvyrkov@linaro.org" ;;
-        llvm:linux) CI_MAIL_RECIPIENTS="$CI_MAIL_RECIPIENTS, arnd@linaro.org, mark.brown@linaro.org, ndesaulniers@google.com, trong@google.com" ;;
-        llvm:llvm) CI_MAIL_RECIPIENTS="$CI_MAIL_RECIPIENTS, adhemerval.zanella@linaro.org, maxim.kuvyrkov@linaro.org, ndesaulniers@google.com, trong@google.com, yvan.roux@linaro.org" ;;
-    esac
-
-    cat > artifacts/ci_mail_parameters.sh <<EOF
-CI_MAIL_RECIPIENTS="$CI_MAIL_RECIPIENTS"
+    good_name="last_good"
+    good_sha1="$last_good"
+    bad_name="first_bad"
+    bad_sha1="$first_bad"
+    cat >> $artifacts/ci_mail_parameters.sh <<EOF
 CI_MAIL_BODY="Successfully identified regression in $current_project on $target @ $toolchain-${rr[${toolchain}_version]} @ linux-${rr[linux_version]}-$linux_config between bad $bad_rev and baseline $baseline_rev .
 
 Culprit:
@@ -238,34 +250,48 @@ Culprit:
 $(git -C $current_project log -n 1 $first_bad | tr '"' "'")
 </cut>
 
-Results regressed from (for $last_good)
+EOF
+else
+    good_name="baseline"
+    good_sha1="$baseline_rev"
+    bad_name="bad"
+    bad_sha1="$bad_rev"
+    cat >> $artifacts/ci_mail_parameters.sh <<EOF
+CI_MAIL_BODY="Could not identify regression in $current_project on $target @ $toolchain-${rr[${toolchain}_version]} @ linux-${rr[linux_version]}-$linux_config between bad $bad_rev and baseline $baseline_rev down to a single commit.  See 'Bisect log' in the links below for bisection details.
+
+EOF
+fi
+
+cat >> $artifacts/ci_mail_parameters.sh <<EOF
+Results regressed from (for $good_name == $good_sha1)
 
 <cut>
-$(cat artifacts/build-$last_good-last_good/results)
+$(cat $artifacts/build-$good_sha1-$good_name/results)
 </cut>
 
-to (for $first_bad)
+to (for $bad_name == $bad_sha1)
 
 <cut>
-$(cat artifacts/build-$first_bad-first_bad/results)
+$(cat $artifacts/build-$bad_sha1-$bad_name/results)
 </cut>
 
-Artifacts of first_bad build: ${BUILD_URL}artifact/artifacts/build-$first_bad-first_bad/
-Artifacts of last_good build: ${BUILD_URL}artifact/artifacts/build-$last_good-last_good/
+Artifacts of $good_name build: ${BUILD_URL}artifact/artifacts/build-$good_sha1-$good_name/
+Artifacts of $bad_name build: ${BUILD_URL}artifact/artifacts/build-$bad_sha1-$bad_name/
 
 Reproduce builds:
 <cut>
-mkdir investigate-$current_project-$first_bad
-cd investigate-$current_project-$first_bad
+mkdir investigate-$current_project-$bad_sha1
+cd investigate-$current_project-$bad_sha1
 git clone https://git.linaro.org/toolchain/jenkins-scripts
-wget ${BUILD_URL}artifact/artifacts/build-manifest.sh
-mkdir reproduce-good
-cd reproduce-good
-../jenkins-scripts/tcwg_kernel-build.sh @@ ../build-manifest.sh ==rr[${current_project}_rev] $last_good
+mkdir reproduce-$good_name
+cd reproduce-$good_name
+wget ${BUILD_URL}artifact/artifacts/build-$good_sha1-$good_name/jenkins/manifest.sh
+../jenkins-scripts/tcwg_kernel-build.sh @@ manifest.sh
 cd ..
-mkdir reproduce-bad
-cd reproduce-bad
-../jenkins-scripts/tcwg_kernel-build.sh @@ ../build-manifest.sh ==rr[${current_project}_rev] $first_bad
+mkdir reproduce-$bad_name
+cd reproduce-$bad_name
+wget ${BUILD_URL}artifact/artifacts/build-$bad_sha1-$bad_name/jenkins/manifest.sh
+../jenkins-scripts/tcwg_kernel-build.sh @@ manifest.sh
 cd ..
 </cut>
 
@@ -275,6 +301,10 @@ Bisect log: ${BUILD_URL}artifact/artifacts/bisect.log/*view*/
 Artifacts: ${BUILD_URL}artifact/artifacts/
 Build URL: $BUILD_URL
 Build log: ${BUILD_URL}consoleText
+EOF
+
+if [ -f $artifacts/first-bad ]; then
+    cat >> $artifacts/ci_mail_parameters.sh <<EOF
 
 Full commit:
 <cut>
@@ -282,12 +312,6 @@ $(git -C $current_project show $first_bad | tr '"' "'")
 </cut>
 "
 EOF
-    chmod +x artifacts/ci_mail_parameters.sh
 fi
 
-# Trigger master build now instead of waiting for next timed SCM trigger.
-cat > $artifacts/trigger-2-build-master <<EOF
-current_project=$current_project
-EOF
-
 trap "" EXIT