From 904e9905edfd1d066f0e3f1145b06f2e717f229d Mon Sep 17 00:00:00 2001
From: Mike Frysinger <vapier@chromium.org>
Date: Wed, 14 Mar 2012 18:45:41 -0400
Subject: [PATCH] cros_workon: mask non-live versions

People who start working on a package and edit the ebuild but accidentally
introduce an error (such as invalid DEPEND) often times don't notice.  When
they do `emerge-$BOARD` on that package, portage falls back to the non-live
version automatically.  Then developers waste time trying to figure out why
their changes aren't working.  Further, emerge doesn't even tell them why
it skipped the live version.  The only way to find that out is by doing:
	emerge-$BOARD '=foo-9999'

Instead, when someone starts working on a package, automatically mask the
non-live version.  That way when they attempt to emerge things, portage
fails immediately with an error message explaining why.

This does make it hard to manually emerge the non-live version like so:
	emerge-$BOARD '<foo-9999'
but considering the number of times I've helped people with this behavior
(they added a bug to the 9999 version and couldn't figure it out), that's
a small downside to an otherwise significant improvement.  If they really
want to install the non-live version, they can do `cros_workon stop` and
then emerge it.

BUG=chromium-os:27494
TEST=`./cros_workon --board x86-alex start metrics`
     `emerge-x86-alex metrics` installs the live version
     edit metrics-9999.ebuild to add bogus depend
     `emerge-x86-alex metrics` fails explaining error in 9999 version

Change-Id: Ia1843424d771d7dce340a04b27bb164714085520
Reviewed-on: https://gerrit.chromium.org/gerrit/18175
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Commit-Ready: Mike Frysinger <vapier@chromium.org>
---
 cros_workon | 50 ++++++++++++++++++++++++++++++--------------------
 1 file changed, 30 insertions(+), 20 deletions(-)

diff --git a/cros_workon b/cros_workon
index 7a7f7d3873..3f3e35627b 100755
--- a/cros_workon
+++ b/cros_workon
@@ -71,25 +71,31 @@ else
 fi
 
 WORKON_DIR=${CHROOT_TRUNK_DIR}/.config/cros_workon
-KEYWORDS_DIR=${BOARD_DIR}/etc/portage/package.keywords
-UNMASK_DIR=${BOARD_DIR}/etc/portage/package.unmask
+CONFIG_DIR=${BOARD_DIR}/etc/portage
+KEYWORDS_DIR=${CONFIG_DIR}/package.keywords
+MASK_DIR=${CONFIG_DIR}/package.mask
+UNMASK_DIR=${CONFIG_DIR}/package.unmask
 WORKON_FILE=${WORKON_DIR}/${FLAGS_board:-host}
+MASK_WORKON_FILE=${WORKON_FILE}.mask
 KEYWORDS_FILE=${KEYWORDS_DIR}/cros-workon
+MASK_FILE=${MASK_DIR}/cros-workon
 UNMASK_FILE=${UNMASK_DIR}/cros-workon
 CHROME_ATOM=chromeos-base/chromeos-chrome
 
 mkdir -p "${WORKON_DIR}" || die "mkdir -p ${WORKON_DIR}"
-touch "${WORKON_FILE}" || die "touch ${WORKON_FILE}"
+touch "${WORKON_FILE}" "${MASK_WORKON_FILE}" || \
+  die "touch ${WORKON_FILE} ${MASK_WORKON_FILE}"
 cmds=(
-  "mkdir -p '${KEYWORDS_DIR}' '${UNMASK_DIR}'"
+  "mkdir -p '${KEYWORDS_DIR}' '${MASK_DIR}' '${UNMASK_DIR}'"
 
   # Clobber and re-create the WORKON_FILE symlinks every time. This
   # is a trivial operation and eliminates all kinds of corner cases
   # as well as any possible future renames of WORKON_FILE.
   # In particular, chroot is usually built as "amd64-host" but becomes
   # just "host" after installation. crosbug.com/23096
-  "rm -f '${KEYWORDS_FILE}' '${UNMASK_FILE}'"
+  "rm -f '${KEYWORDS_FILE}' '${MASK_FILE}' '${UNMASK_FILE}'"
   "ln -s '${WORKON_FILE}' '${KEYWORDS_FILE}'"
+  "ln -s '${MASK_WORKON_FILE}' '${MASK_FILE}'"
   "ln -s '${WORKON_FILE}' '${UNMASK_FILE}'"
 )
 sudo_multi "${cmds[@]}"
@@ -288,42 +294,46 @@ chrome_to_live () {
 # src_unpack step fetches the package source for local development.
 ebuild_to_live () {
   local atoms=$1
-  local atoms_success=""
+  local atoms_success=()
   local atom
 
   for atom in ${atoms}; do
     if ! grep -qx "=${atom}-9999" "${WORKON_FILE}" ; then
-      if echo "=${atom}-9999" >> "${WORKON_FILE}" ; then
-        atoms_success="${atoms_success} ${atom}"
-        if [ "${atom}" = "${CHROME_ATOM}" ]; then
-          chrome_to_live
-        fi
+      echo "=${atom}-9999" >> "${WORKON_FILE}" || \
+        die "Could not update ${WORKON_FILE} with ${atom}"
+      echo "<${atom}-9999" >> "${MASK_WORKON_FILE}" || \
+        die "Could not update ${MASK_WORKON_FILE} with ${atom}"
+      atoms_success+=( ${atom} )
+      if [ "${atom}" = "${CHROME_ATOM}" ]; then
+        chrome_to_live
       fi
     else
       warn "Already working on ${atom}"
     fi
   done
-  [ -n "${atoms_success}" ] && regen_manifest_and_sync && \
-    info "Started working on '${atoms_success/ /}' for '${BOARD_STR}'"
+  [ ${#atoms_success[@]} -gt 0 ] && regen_manifest_and_sync && \
+    info "Started working on '${atoms_success[*]}' for '${BOARD_STR}'"
 }
 
 # Move a live development ebuild back to stable.
 ebuild_to_stable () {
   local atoms=$1
-  local atoms_success=""
+  local atoms_success=()
   local atom
 
   for atom in ${atoms}; do
-    if grep -qx "=${atom}-9999" "${WORKON_FILE}" ; then
-      if sed -i -e "/^=${atom/\//\\/}-9999\$/d" "${WORKON_FILE}" ; then
-        atoms_success="${atoms_success} ${atom}"
-      fi
+    if grep -qx "=${atom}-9999" "${WORKON_FILE}" "${MASK_WORKON_FILE}" ; then
+      sed -i -e "/^=${atom/\//\\/}-9999\$/d" "${WORKON_FILE}" || \
+        die "Could not update ${WORKON_FILE} with ${atom}"
+      sed -i -e "/^<${atom/\//\\/}-9999\$/d" "${MASK_WORKON_FILE}" || \
+        die "Could not update ${WORKON_FILE} with ${atom}"
+      atoms_success+=( ${atom} )
     else
       warn "Not working on ${atom}"
     fi
   done
-  [ -n "${atoms_success}" ] && \
-    info "Stopped working on '${atoms_success/ /}' for '${BOARD_STR}'"
+  [ ${#atoms_success[@]} -gt 0 ] && \
+    info "Stopped working on '${atoms_success[*]}' for '${BOARD_STR}'"
 }
 
 # Run a command on all or a set of repos.