Add flag to force clobbering of index in gdb-add-index

build/gdb-add-index

 #!/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.
 #
 # Saves the gdb index for a given binary and its shared library dependencies.
 #
 # This will run gdb index in parallel on a number of binaries using SIGUSR1
 # as the communication mechanism to simulate a semaphore. Because of the
 # nature of this technique, using "set -e" is very difficult. The SIGUSR1
@@ skipping 18 matching lines @@
     echo -n "Removing temp directory $DIRECTORY..."
     rm -rf $DIRECTORY
     echo done
   fi
 }
 
 # Add index to one binary.
 function index_one_file {
   local file=$1
   local basename=$(basename "$file")
+  local should_index="${SHOULD_INDEX}"
 
   local readelf_out=$(readelf -S "$file")
   if [[ $readelf_out =~ "gdb_index" ]]; then
-    echo "Skipped $basename -- already contains index."
-  else
+    if [ "${REMOVE_INDEX}" = 1 ]; then
+      objcopy --remove-section .gdb_index "$file"
+      echo "Removed index from $basename."
+    else
+      echo "Skipped $basename -- already contains index."
+      should_index=0
+    fi
+  fi
+
+  if [ "${should_index}" = 1 ]; then
     local start=$(date +"%s%N")
     echo "Adding index to $basename..."
 
     gdb -batch "$file" -ex "save gdb-index $DIRECTORY" -ex "quit"
     local index_file="$DIRECTORY/$basename.gdb-index"
     if [ -f "$index_file" ]; then
       objcopy --add-section .gdb_index="$index_file" \
         --set-section-flags .gdb_index=readonly "$file" "$file"
       local finish=$(date +"%s%N")
       local elappsed=$(((finish - start)/1000000))
@@ skipping 22 matching lines @@
   fi
 
   async_index "${FILES_TO_INDEX[CUR_FILE_NUM]}"
   ((CUR_FILE_NUM += 1)) || true
 }
 
 
 ########
 ### Main body of the script.
 
+REMOVE_INDEX=0
+SHOULD_INDEX=1
+while getopts ":f:r" opt; do
+  case $opt in
+    f)
+      REMOVE_INDEX=1
+      shift
+      ;;
+    r)
+      REMOVE_INDEX=1
+      SHOULD_INDEX=0
+      shift
+      ;;
+    *)
+      echo "Invalid option: -$OPTARG" >&2
+      ;;
+  esac
+done
+
 if [[ ! $# == 1 ]]; then
-  echo "Usage: $0 path-to-binary"
+  echo "Usage: $0 [-f] [-r] path-to-binary"
+  echo "  -f forces replacement of an existing index."
+  echo "  -r removes the index section."
   exit 1
 fi
 
 FILENAME="$1"
 if [[ ! -f "$FILENAME" ]]; then
   echo "Path $FILENAME does not exist."
   exit 1
 fi
 
 # Ensure we cleanup on on exit.
@@ skipping 24 matching lines @@
 
 # Do a wait loop. Bash waits that terminate due a trap have an exit
 # code > 128. We also ensure that our subshell's "normal" exit occurs with
 # an exit code > 128. This allows us to do consider a > 128 exit code as
 # an indication that the loop should continue. Unfortunately, it also means
 # we cannot use set -e since technically the "wait" is failing.
 wait
 while (( $? > 128 )); do
   wait
 done