Selective build clobbering feature (landmines.py and android build scripts).

build/android/buildbot/buildbot_functions.sh

 #!/bin/bash
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 #
 # Bash functions used by buildbot annotator scripts for the android
 # build of chromium.  Executing this script should not perform actions
 # other than setting variables and defining of functions.
 
 # Number of jobs on the compile line; e.g.  make -j"${JOBS}"
 JOBS="${JOBS:-4}"
 
 # Parse named arguments passed into the annotator script
 # and assign them global variable names.
 function bb_parse_args {
   while [[ $1 ]]; do
     case "$1" in
       --factory-properties=*)
         FACTORY_PROPERTIES="$(echo "$1" | sed 's/^[^=]*=//')"
         BUILDTYPE=$(bb_get_json_prop "$FACTORY_PROPERTIES" target)
+        BUILDTOOL=$(bb_get_json_prop "$FACTORY_PROPERTIES" buildtool)
         ;;
       --build-properties=*)
         BUILD_PROPERTIES="$(echo "$1" | sed 's/^[^=]*=//')"
         ;;
       *)
         echo "@@@STEP_WARNINGS@@@"
         echo "Warning, unparsed input argument: '$1'"
         ;;
     esac
     shift
   done
 }
 
 # Function to force-green a bot.
 function bb_force_bot_green_and_exit {
   echo "@@@BUILD_STEP Bot forced green.@@@"
   exit 0
 }
 
+# Check for landmines which might clobber the build. Will create a new annotator
+# step for the clobber if one is required.
+#
+# As a side effect, creates "$2/.landmines"
+#
+# Args:
+#   $1: source root
+#   $2: output root
+# Retval:
+#   0 if landmines are tripped for this build and we need clobber OR
+#        clobber was requested via $BUILDBOT_CLOBBER
+#   1 if landmines are dormant
+function bb_check_clobber {
+  local src_root="$1"
+  local out_dir="$2"
+
+  local ret=1
+
+  if [[ $BUILDBOT_CLOBBER ]]
+  then
+    echo "@@@BUILD_STEP Clobber@@@"
+    echo "Clobber explicitly requested"
+    ret=0
+  else
+    local landmines_path="$out_dir/.landmines"
+    local landmines_script="$src_root/build/landmines.py"
+    [[ ! -x "$landmines_script" ]] || return 1
+
+    local new_landmines=$(mktemp)
+
+    python "$landmines_script" >> "$new_landmines" <<EOF
+    {
+      "target": "$BUILDTYPE",
+      "distributor": "goma",
+      "platform": "android",
+      "builder": "$BUILDTOOL"
+    }
+EOF
+
+    if [[ ! -f "$landmines_path" ]]
+    then
+      mkdir -p "$(dirname "$landmines_path")"
+      mv "$new_landmines" "$landmines_path"
+    else
+      local diff_output=$(mktemp)
+      diff -U 0 --label "old_landmines $(stat -c "%z" "$landmines_path")" \
+                "$landmines_path"                                         \
+                --label "new_landmines $(stat -c "%z" "$new_landmines")"  \
+                "$new_landmines" > "$diff_output"
+      if [[ $? != 0 ]]
+      then
+        echo "@@@BUILD_STEP Clobber@@@"
+        echo "Landmines tripped! Clobbering the build! Reasons for clobber:"
+        cat "$diff_output"
+        ret=0
+      fi
+      rm -f "$diff_output"
+    fi
+
+    rm -f "$new_landmines"
+  fi
+
+  return $ret
+}
+
 # Basic setup for all bots to run after a source tree checkout.
 # Args:
 #   $1: source root.
 #   $2 and beyond: key value pairs which are parsed by bb_parse_args.
 function bb_baseline_setup {
   SRC_ROOT="$1"
   # Remove SRC_ROOT param
   shift
   cd $SRC_ROOT
 
-  if [[ $BUILDBOT_CLOBBER ]]; then
-    echo "@@@BUILD_STEP Clobber@@@"
+  echo "@@@BUILD_STEP Parse args@@@"
+  bb_parse_args "$@"
+
+  if bb_check_clobber "$SRC_ROOT" "$SRC_ROOT/out/$BUILDTYPE"
+  then
     # Sdk key expires, delete android folder.
     # crbug.com/145860
     rm -rf ~/.android
     rm -rf "${SRC_ROOT}"/out
     if [ -e "${SRC_ROOT}"/out ] ; then
       echo "Clobber appeared to fail?  ${SRC_ROOT}/out still exists."
       echo "@@@STEP_WARNINGS@@@"
     fi
   fi
 
   echo "@@@BUILD_STEP Environment setup@@@"
-  bb_parse_args "$@"
-
-  local BUILDTOOL=$(bb_get_json_prop "$FACTORY_PROPERTIES" buildtool)
   if [[ $BUILDTOOL = ninja ]]; then
     export GYP_GENERATORS=ninja
   fi
   export GOMA_DIR=/b/build/goma
   . build/android/envsetup.sh
   adb kill-server
 }
 
 function bb_compile_setup {
   local extra_gyp_defines="$(bb_get_json_prop "$FACTORY_PROPERTIES" \
@@ skipping 72 matching lines @@
   ninja -C out/$BUILDTYPE -j120 -l20 $TARGET
 }
 
 # Compile step
 function bb_compile {
   bb_compile_setup
   # This must be named 'compile', not 'Compile', for CQ interaction.
   # Talk to maruel for details.
   echo "@@@BUILD_STEP compile@@@"
 
-  BUILDTOOL=$(bb_get_json_prop "$FACTORY_PROPERTIES" buildtool)
   if [[ $BUILDTOOL = ninja ]]; then
     bb_goma_ninja All
   else
     bb_goma_make
   fi
 
   bb_stop_goma_internal
 }
 
 # Experimental compile step; does not turn the tree red if it fails.
@@ skipping 130 matching lines @@
   )
 }
 
 # Retrieve a packed json property using python
 function bb_get_json_prop {
   local JSON="$1"
   local PROP="$2"
 
   python -c "import json; print json.loads('$JSON').get('$PROP', '')"
 }