gdb/contrib/gdb-add-index.sh

   1 #! /bin/sh
   2
   3 # Add a .gdb_index section to a file.
   4
   5 # Copyright (C) 2010-2025 Free Software Foundation, Inc.
   6 # This program is free software; you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation; either version 3 of the License, or
   9 # (at your option) any later version.
  10 #
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18
  19 # This program assumes gdb and objcopy are in $PATH.
  20 # If not, or you want others, pass the following in the environment
  21 GDB=${GDB:=gdb}
  22 OBJCOPY=${OBJCOPY:=objcopy}
  23 READELF=${READELF:=readelf}
  24
  25 PKGVERSION="@PKGVERSION@"
  26 VERSION="@VERSION@"
  27
  28 myname="${0##*/}"
  29
  30 print_usage() {
  31     prefix="Usage: $myname"
  32     echo "$prefix [-h|--help] [-v|--version] [--dwarf-5] FILENAME"
  33 }
  34
  35 print_try_help() {
  36     echo "Try '$myname --help' for more information."
  37 }
  38
  39 print_help() {
  40     print_usage
  41     echo
  42     echo "Add a .gdb_index section to FILENAME to facilitate faster debug"
  43     echo "information loading by GDB."
  44     echo
  45     echo "  -h, --help         Print this message then exit."
  46     echo "  -v, --version      Print version information then exit."
  47     echo "  --dwarf-5          Add the DWARF-5 style .debug_names section"
  48     echo "                       instead of .gdb_index."
  49 }
  50
  51 print_version() {
  52     echo "GNU gdb-add-index (${PKGVERSION}) ${VERSION}"
  53 }
  54
  55 dwarf5=""
  56
  57 # Parse options.
  58 until
  59 opt=$1
  60 case ${opt} in
  61     --dwarf-5 | -dwarf-5)
  62         dwarf5="-dwarf-5"
  63         ;;
  64
  65     --help | -help | -h)
  66         print_help
  67         exit 0
  68         ;;
  69
  70     --version | -version | -v)
  71         print_version
  72         exit 0
  73         ;;
  74
  75     -?*)
  76         print_try_help 1>&2
  77         exit 2
  78         ;;
  79
  80     *)
  81         # No arguments remaining.
  82         ;;
  83 esac
  84 # Break from loop if the first character of OPT is not '-'.
  85 [ "x$(printf %.1s "$opt")" != "x-" ]
  86 do
  87     shift
  88 done
  89
  90 if test $# != 1; then
  91     print_try_help
  92     exit 1
  93 fi
  94
  95 file="$1"
  96
  97 if test -L "$file"; then
  98     if ! command -v readlink >/dev/null 2>&1; then
  99         echo "$myname: 'readlink' missing.  Failed to follow symlink $1." 1>&2
 100         exit 1
 101     fi
 102
 103     # Count number of links followed in order to detect loops.
 104     count=0
 105     while test -L "$file"; do
 106         target=$(readlink "$file")
 107
 108         case "$target" in
 109             /*)
 110                 file="$target"
 111                 ;;
 112             *)
 113                 file="$(dirname "$file")/$target"
 114                 ;;
 115         esac
 116
 117         count="$((count + 1))"
 118         if test "$count" -gt 10; then
 119             echo "$myname: Detected loop while following link $file"
 120             exit 1
 121         fi
 122     done
 123 fi
 124
 125 if test ! -r "$file"; then
 126     echo "$myname: unable to access: $file" 1>&2
 127     exit 1
 128 fi
 129
 130 dir="${file%/*}"
 131 test "$dir" = "$file" && dir="."
 132
 133 dwz_file=""
 134 if $READELF -S "$file" | grep -q " \.gnu_debugaltlink "; then
 135     dwz_file=$($READELF --string-dump=.gnu_debugaltlink "$file" \
 136                    | grep -A1  "'\.gnu_debugaltlink':" \
 137                    | tail -n +2 \
 138                    | sed 's/.*]//')
 139     dwz_file=$(echo $dwz_file)
 140     if $READELF -S "$dwz_file" | grep -E -q " \.(gdb_index|debug_names) "; then
 141         # Already has an index, skip it.
 142         dwz_file=""
 143     fi
 144 fi
 145
 146 set_files ()
 147 {
 148     fpath="$1"
 149
 150     index4="${fpath}.gdb-index"
 151     index5="${fpath}.debug_names"
 152     debugstr="${fpath}.debug_str"
 153     debugstrmerge="${fpath}.debug_str.merge"
 154     debugstrerr="${fpath}.debug_str.err"
 155 }
 156
 157 tmp_files=
 158 for f in "$file" "$dwz_file"; do
 159     if [ "$f" = "" ]; then
 160         continue
 161     fi
 162     set_files "$f"
 163     tmp_files="$tmp_files $index4 $index5 $debugstr $debugstrmerge $debugstrerr"
 164 done
 165
 166 rm -f $tmp_files
 167
 168 # Ensure intermediate index file is removed when we exit.
 169 trap "rm -f $tmp_files" 0
 170
 171 $GDB --batch -nx -iex 'set auto-load no' \
 172     -iex 'set debuginfod enabled off' \
 173     -ex "file '$file'" -ex "save gdb-index $dwarf5 '$dir'" || {
 174     # Just in case.
 175     status=$?
 176     echo "$myname: gdb error generating index for $file" 1>&2
 177     exit $status
 178 }
 179
 180 # In some situations gdb can exit without creating an index.  This is
 181 # not an error.
 182 # E.g., if $file is stripped.  This behavior is akin to stripping an
 183 # already stripped binary, it's a no-op.
 184 status=0
 185
 186 handle_file ()
 187 {
 188     fpath="$1"
 189
 190     set_files "$fpath"
 191
 192     if test -f "$index4" -a -f "$index5"; then
 193         echo "$myname: Both index types were created for $fpath" 1>&2
 194         status=1
 195     elif test -f "$index4" -o -f "$index5"; then
 196         if test -f "$index4"; then
 197             index="$index4"
 198             section=".gdb_index"
 199         else
 200             index="$index5"
 201             section=".debug_names"
 202         fi
 203         if test -s "$debugstr"; then
 204             if ! $OBJCOPY --dump-section .debug_str="$debugstrmerge" "$fpath" \
 205                  /dev/null 2> "$debugstrerr"; then
 206                 cat >&2 "$debugstrerr"
 207                 exit 1
 208             fi
 209             cat "$debugstr" >>"$debugstrmerge"
 210             if grep -q "can't dump section '.debug_str' - it does not exist" \
 211                     "$debugstrerr"; then
 212                 $OBJCOPY --add-section $section="$index" \
 213                          --set-section-flags $section=readonly \
 214                          --add-section .debug_str="$debugstrmerge" \
 215                          --set-section-flags .debug_str=readonly \
 216                          "$fpath" "$fpath"
 217             else
 218                 $OBJCOPY --add-section $section="$index" \
 219                          --set-section-flags $section=readonly \
 220                          --update-section .debug_str="$debugstrmerge" \
 221                          "$fpath" "$fpath"
 222             fi
 223         else
 224             $OBJCOPY --add-section $section="$index" \
 225                      --set-section-flags $section=readonly \
 226                      "$fpath" "$fpath"
 227         fi
 228
 229         status=$?
 230     else
 231         echo "$myname: No index was created for $fpath" 1>&2
 232         echo "$myname: [Was there no debuginfo? Was there already an index?]" \
 233              1>&2
 234     fi
 235 }
 236
 237 handle_file "$file"
 238 if [ "$dwz_file" != "" ]; then
 239     handle_file "$dwz_file"
 240 fi
 241
 242 exit $status