gdb/contrib/gdb-add-index.sh

   1 #! /bin/sh
   2
   3 # Add a .gdb_index section to a file.
   4
   5 # Copyright (C) 2010-2021 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 myname="${0##*/}"
  26
  27 dwarf5=""
  28 if [ "$1" = "-dwarf-5" ]; then
  29     dwarf5="$1"
  30     shift
  31 fi
  32
  33 if test $# != 1; then
  34     echo "usage: $myname [-dwarf-5] FILE" 1>&2
  35     exit 1
  36 fi
  37
  38 file="$1"
  39
  40 if test -L "$file"; then
  41     if ! command -v readlink >/dev/null 2>&1; then
  42         echo "$myname: 'readlink' missing.  Failed to follow symlink $1." 1>&2
  43         exit 1
  44     fi
  45
  46     # Count number of links followed in order to detect loops.
  47     count=0
  48     while test -L "$file"; do
  49         target=$(readlink "$file")
  50
  51         case "$target" in
  52             /*)
  53                 file="$target"
  54                 ;;
  55             *)
  56                 file="$(dirname "$file")/$target"
  57                 ;;
  58         esac
  59
  60         count="$((count + 1))"
  61         if test "$count" -gt 10; then
  62             echo "$myname: Detected loop while following link $file"
  63             exit 1
  64         fi
  65     done
  66 fi
  67
  68 if test ! -r "$file"; then
  69     echo "$myname: unable to access: $file" 1>&2
  70     exit 1
  71 fi
  72
  73 dir="${file%/*}"
  74 test "$dir" = "$file" && dir="."
  75
  76 dwz_file=""
  77 if $READELF -S "$file" | grep -q " \.gnu_debugaltlink "; then
  78     dwz_file=$($READELF --string-dump=.gnu_debugaltlink "$file" \
  79                    | grep -A1  "'\.gnu_debugaltlink':" \
  80                    | tail -n +2 \
  81                    | sed 's/.*]//')
  82     dwz_file=$(echo $dwz_file)
  83     if $READELF -S "$dwz_file" | grep -E -q " \.(gdb_index|debug_names) "; then
  84         # Already has an index, skip it.
  85         dwz_file=""
  86     fi
  87 fi
  88
  89 set_files ()
  90 {
  91     fpath="$1"
  92
  93     index4="${fpath}.gdb-index"
  94     index5="${fpath}.debug_names"
  95     debugstr="${fpath}.debug_str"
  96     debugstrmerge="${fpath}.debug_str.merge"
  97     debugstrerr="${fpath}.debug_str.err"
  98 }
  99
 100 tmp_files=
 101 for f in "$file" "$dwz_file"; do
 102     if [ "$f" = "" ]; then
 103         continue
 104     fi
 105     set_files "$f"
 106     tmp_files="$tmp_files $index4 $index5 $debugstr $debugstrmerge $debugstrerr"
 107 done
 108
 109 rm -f $tmp_files
 110
 111 # Ensure intermediate index file is removed when we exit.
 112 trap "rm -f $tmp_files" 0
 113
 114 $GDB --batch -nx -iex 'set auto-load no' \
 115     -ex "file $file" -ex "save gdb-index $dwarf5 $dir" || {
 116     # Just in case.
 117     status=$?
 118     echo "$myname: gdb error generating index for $file" 1>&2
 119     exit $status
 120 }
 121
 122 # In some situations gdb can exit without creating an index.  This is
 123 # not an error.
 124 # E.g., if $file is stripped.  This behaviour is akin to stripping an
 125 # already stripped binary, it's a no-op.
 126 status=0
 127
 128 handle_file ()
 129 {
 130     fpath="$1"
 131
 132     set_files "$fpath"
 133
 134     if test -f "$index4" -a -f "$index5"; then
 135         echo "$myname: Both index types were created for $fpath" 1>&2
 136         status=1
 137     elif test -f "$index4" -o -f "$index5"; then
 138         if test -f "$index4"; then
 139             index="$index4"
 140             section=".gdb_index"
 141         else
 142             index="$index5"
 143             section=".debug_names"
 144         fi
 145         debugstradd=false
 146         debugstrupdate=false
 147         if test -s "$debugstr"; then
 148             if ! $OBJCOPY --dump-section .debug_str="$debugstrmerge" "$fpath" \
 149                  /dev/null 2>$debugstrerr; then
 150                 cat >&2 $debugstrerr
 151                 exit 1
 152             fi
 153             if grep -q "can't dump section '.debug_str' - it does not exist" \
 154                     $debugstrerr; then
 155                 debugstradd=true
 156             else
 157                 debugstrupdate=true
 158                 cat >&2 $debugstrerr
 159             fi
 160             cat "$debugstr" >>"$debugstrmerge"
 161         fi
 162
 163         $OBJCOPY --add-section $section="$index" \
 164                  --set-section-flags $section=readonly \
 165                  $(if $debugstradd; then \
 166                        echo --add-section .debug_str="$debugstrmerge"; \
 167                        echo --set-section-flags .debug_str=readonly; \
 168                    fi; \
 169                    if $debugstrupdate; then \
 170                        echo --update-section .debug_str="$debugstrmerge"; \
 171                    fi) \
 172                  "$fpath" "$fpath"
 173
 174         status=$?
 175     else
 176         echo "$myname: No index was created for $fpath" 1>&2
 177         echo "$myname: [Was there no debuginfo? Was there already an index?]" \
 178              1>&2
 179     fi
 180 }
 181
 182 handle_file "$file"
 183 if [ "$dwz_file" != "" ]; then
 184     handle_file "$dwz_file"
 185 fi
 186
 187 exit $status