gdb-add-index: accept a list of files to index

Previously gdb-add-index took a single binary argument to index. It uses
ldd to get its dependencies and index those too. Now it accepts more than
one file, along with a -n option to not attempt to extract dependencies.
This is useful for Android development where there's no single
binary to index. Now you can do gdb-add-index -n out/Debug/lib.unstripped/*

This CL also cleans up the style a bit for consistency.

BUG=

Review URL: https://codereview.chromium.org/1471523002

Cr-Commit-Position: refs/heads/master@{#361227}

build/gdb-add-index

@@ -13,6 +13,17 @@
 # When modifying this code, most of the real logic is in the index_one_file
 # function. The rest is cleanup + sempahore plumbing.
 
+function usage_exit {
+  echo "Usage: $0 [-f] [-r] [-n] <paths-to-binaries>..."
+  echo "  -f forces replacement of an existing index."
+  echo "  -r removes the index section."
+  echo "  -n don't extract the dependencies of each binary with lld."
+  echo "       e.g., $0 -n out/Debug/lib.unstripped/lib*"
+  echo
+  echo "  Set TOOLCHAIN_PREFIX to use a non-default set of binutils."
+  exit 1
+}
+
 # Cleanup temp directory and ensure all child jobs are dead-dead.
 function on_exit {
   trap "" EXIT USR1  # Avoid reentrancy.
@@ -25,9 +36,9 @@ function on_exit {
     echo "done"
   fi
 
-  if [ -f "$DIRECTORY" ]; then
-    echo -n "Removing temp directory $DIRECTORY..."
-    rm -rf $DIRECTORY
+  if [ -f "$directory" ]; then
+    echo -n "Removing temp directory $directory..."
+    rm -rf "$directory"
     echo done
   fi
 }
@@ -36,31 +47,31 @@ function on_exit {
 function index_one_file {
   local file=$1
   local basename=$(basename "$file")
-  local should_index="${SHOULD_INDEX}"
+  local should_index_this_file="${should_index}"
 
   local readelf_out=$(${TOOLCHAIN_PREFIX}readelf -S "$file")
   if [[ $readelf_out =~ "gdb_index" ]]; then
-    if [ "${REMOVE_INDEX}" = 1 ]; then
+    if $remove_index; then
       ${TOOLCHAIN_PREFIX}objcopy --remove-section .gdb_index "$file"
       echo "Removed index from $basename."
     else
       echo "Skipped $basename -- already contains index."
-      should_index=0
+      should_index_this_file=false
     fi
   fi
 
-  if [ "${should_index}" = 1 ]; then
+  if $should_index_this_file; then
     local start=$(date +"%s%N")
     echo "Adding index to $basename..."
 
-    ${TOOLCHAIN_PREFIX}gdb -batch "$file" -ex "save gdb-index $DIRECTORY" \
+    ${TOOLCHAIN_PREFIX}gdb -batch "$file" -ex "save gdb-index $directory" \
       -ex "quit"
-    local index_file="$DIRECTORY/$basename.gdb-index"
+    local index_file="$directory/$basename.gdb-index"
     if [ -f "$index_file" ]; then
       ${TOOLCHAIN_PREFIX}objcopy --add-section .gdb_index="$index_file" \
         --set-section-flags .gdb_index=readonly "$file" "$file"
       local finish=$(date +"%s%N")
-      local elapsed=$(((finish - start)/1000000))
+      local elapsed=$(((finish - start) / 1000000))
       echo "   ...$basename indexed. [${elapsed}ms]"
     else
       echo "   ...$basename unindexable."
@@ -79,75 +90,86 @@ function async_index {
   } &
 }
 
-CUR_FILE_NUM=0
+cur_file_num=0
 function index_next {
-  if (( CUR_FILE_NUM >= ${#FILES_TO_INDEX[@]} )); then
+  if ((cur_file_num >= ${#files_to_index[@]})); then
     return
   fi
 
-  async_index "${FILES_TO_INDEX[CUR_FILE_NUM]}"
-  ((CUR_FILE_NUM += 1)) || true
+  async_index "${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 $opt in
-    f)
-      REMOVE_INDEX=1
-      shift
+remove_index=false
+should_index=true
+should_index_deps=true
+files_to_index=()
+while (($# > 0)); do
+  case "$1" in
+    -h)
+      usage_exit
+      ;;
+    -f)
+      remove_index=true
       ;;
-    r)
-      REMOVE_INDEX=1
-      SHOULD_INDEX=0
-      shift
+    -r)
+      remove_index=true
+      should_index=false
+      ;;
+    -n)
+      should_index_deps=false
+      ;;
+    -*)
+      echo "Invalid option: $1" >&2
+      usage_exit
       ;;
     *)
-      echo "Invalid option: -$OPTARG" >&2
+      if [[ ! -f "$1" ]]; then
+        echo "Path $1 does not exist."
+        exit 1
+      fi
+      files_to_index+=("$1")
       ;;
   esac
+  shift
 done
 
-if [[ ! $# == 1 ]]; then
-  echo "Usage: $0 [-f] [-r] path-to-binary"
-  echo "  -f forces replacement of an existing index."
-  echo "  -r removes the index section."
-  exit 1
+if ((${#files_to_index[@]} == 0)); then
+  usage_exit
 fi
 
-FILENAME="$1"
-if [[ ! -f "$FILENAME" ]]; then
-  echo "Path $FILENAME does not exist."
-  exit 1
+dependencies=()
+if $should_index_deps; then
+  for file in "${files_to_index[@]}"; do
+      # Append the shared library dependencies of this file that
+      # have the same dirname. The dirname is a signal that these
+      # shared libraries were part of the same build as the binary.
+      dependencies+=( \
+        $(ldd "$file" 2>/dev/null \
+          | grep $(dirname "$file") \
+          | sed "s/.*[ \t]\(.*\) (.*/\1/") \
+      )
+  done
 fi
+files_to_index+=("${dependencies[@]}")
 
 # Ensure we cleanup on on exit.
-trap on_exit EXIT
+trap on_exit EXIT INT
 
 # We're good to go! Create temp directory for index files.
-DIRECTORY=$(mktemp -d)
-echo "Made temp directory $DIRECTORY."
-
-# Create array with the filename and all shared libraries that
-# have the same dirname. The dirname is a signal that these
-# shared libraries were part of the same build as the binary.
-declare -a FILES_TO_INDEX=($FILENAME
- $(ldd "$FILENAME" 2>/dev/null \
-  | grep $(dirname "$FILENAME") \
-  | sed "s/.*[ \t]\(.*\) (.*/\1/")
-)
+directory=$(mktemp -d)
+echo "Made temp directory $directory."
 
 # Start concurrent indexing.
 trap index_next USR1
 
 # 4 is an arbitrary default. When changing, remember we are likely IO bound
 # so basing this off the number of cores is not sensible.
-INDEX_TASKS=${INDEX_TASKS:-4}
-for ((i=0;i<${INDEX_TASKS};i++)); do
+index_tasks=${INDEX_TASKS:-4}
+for ((i = 0; i < index_tasks; i++)); do
   index_next
 done
 
@@ -157,6 +179,6 @@ done
 # an indication that the loop should continue. Unfortunately, it also means
 # we cannot use set -e since technically the "wait" is failing.
 wait
-while (( $? > 128 )); do
+while (($? > 128)); do
   wait
 done