#!/bin/bash

#find-debuginfo.sh - automagically generate debug info and file list

#for inclusion in an rpm spec file.

#

# Usage: find-debuginfo.sh [-g] [--strict-build-id]

#	 		   [-o debugfiles.list]

#			   [[-l filelist]... [-p 'pattern'] -o debuginfo.list]

#			   [builddir]

#

# The -g flag says to use strip -g instead of full strip on DSOs.

# The --strict-build-id flag says to exit with failure status if

# any ELF binary processed fails to contain a build-id note.

#

# A single -o switch before any -l or -p switches simply renames

# the primary output file from debugfiles.list to something else.

# A -o switch that follows a -p switch or some -l switches produces

# an additional output file with the debuginfo for the files in

# the -l filelist file, or whose names match the -p pattern.

# The -p argument is an egrep-style regexp matching the a file name,

# and must not use anchors (^ or $).

#

# All file names in switches are relative to builddir (. if not given).

#

# With -g arg, pass it to strip on libraries.

strip_g=false

# Barf on missing build IDs.

# XXX temporarily on by default

strict=true

BUILDDIR=.

out=debugfiles.list

nout=0

while [ $# -gt 0 ]; do

  case "$1" in

  --strict-build-id)

    strict=true

    ;;

  -g)

    strip_g=true

    ;;

  -o)

    if [ -z "${lists[$nout]}" -a -z "${ptns[$nout]}" ]; then

      out=$2

    else

      outs[$nout]=$2

      ((nout++))

    fi

    shift

    ;;

  -l)

    lists[$nout]="${lists[$nout]} $2"

    shift

    ;;

  -p)

    ptns[$nout]=$2

    shift

    ;;

  *)

    BUILDDIR=$1

    shift

    break

    ;;

  esac

  shift

done

i=0

while ((i < nout)); do

  outs[$i]="$BUILDDIR/${outs[$i]}"

  l=''

  for f in ${lists[$i]}; do

    l="$l $BUILDDIR/$f"

  done

  lists[$i]=$l

  ((++i))

done

LISTFILE=$BUILDDIR/$out

SOURCEFILE=$BUILDDIR/debugsources.list

LINKSFILE=$BUILDDIR/debuglinks.list

> $SOURCEFILE

> $LISTFILE

> $LINKSFILE

debugdir="${RPM_BUILD_ROOT}/usr/lib/debug"

strip_to_debug()

{

  local g=

  $strip_g && case "$(file -bi "$2")" in

  application/x-sharedlib,*) g=-g ;;

  esac

  eu-strip --remove-comment -f "$1" "$2" || exit

}

# Make a relative symlink to $1 called $3$2

shopt -s extglob

link_relative()

{

  local t="$1" f="$2" pfx="$3"

  local fn="${f#/}" tn="${t#/}"

  local fd td d

  while fd="${fn%%/*}"; td="${tn%%/*}"; [ "$fd" = "$td" ]; do

    fn="${fn#*/}"

    tn="${tn#*/}"

  done

  d="${fn%/*}"

  if [ "$d" != "$fn" ]; then

    d="${d//+([!\/])/..}"

    tn="${d}/${tn}"

  fi

  mkdir -p "$(dirname "$pfx$f")" && ln -snf "$tn" "$pfx$f"

}

# Make a symlink in /usr/lib/debug/$2 to $1

debug_link()

{

  local l="/usr/lib/debug$2"

  local t="$1"

  echo >> $LINKSFILE "$l $t"

  link_relative "$t" "$l" "$RPM_BUILD_ROOT"

}

# Make a build-id symlink for id $1 with suffix $3 to file $2.

make_id_link()

{

  local id="$1" file="$2"

  local idfile=".build-id/${id:0:2}/${id:2}"

  [ $# -eq 3 ] && idfile="${idfile}$3"

  local root_idfile="$RPM_BUILD_ROOT/usr/lib/debug/$idfile"

  if [ ! -L "$root_idfile" ]; then

    debug_link "$file" "/$idfile"

    return

  fi

  [ $# -eq 3 ] && return 0

  local other=$(readlink -m "$root_idfile")

  other=${other#$RPM_BUILD_ROOT}

  if cmp -s "$root_idfile" "$RPM_BUILD_ROOT$file" ||

     eu-elfcmp -q "$root_idfile" "$RPM_BUILD_ROOT$file" 2> /dev/null; then

    # Two copies.  Maybe one has to be setuid or something.

    echo >&2 "*** WARNING: identical binaries are copied, not linked:"

    echo >&2 "        $file"

    echo >&2 "   and  $other"

  else

    # This is pathological, break the build.

    echo >&2 "*** ERROR: same build ID in nonidentical files!"

    echo >&2 "        $file"

    echo >&2 "   and  $other"

    exit 2

  fi

}

get_debugfn()

{

  dn=$(dirname "${1#$RPM_BUILD_ROOT}")

  bn=$(basename "$1" .debug).debug

  debugdn=${debugdir}${dn}

  debugfn=${debugdn}/${bn}

}

set -o pipefail

strict_error=ERROR

$strict || strict_error=WARNING

# Strip ELF binaries

find $RPM_BUILD_ROOT ! -path "${debugdir}/*.debug" -type f \

     		     \( -perm -0100 -or -perm -0010 -or -perm -0001 \) \

		     -print |

file -N -f - | sed -n -e 's/^\(.*\):[ 	]*.*ELF.*, not stripped/\1/p' |

xargs --no-run-if-empty stat -c '%h %D_%i %n' |

while read nlinks inum f; do

  get_debugfn "$f"

  [ -f "${debugfn}" ] && continue

  # If this file has multiple links, keep track and make

  # the corresponding .debug files all links to one file too.

  if [ $nlinks -gt 1 ]; then

    eval linked=\$linked_$inum

    if [ -n "$linked" ]; then

      link=$debugfn

      get_debugfn "$linked"

      echo "hard linked $link to $debugfn"

      ln -nf "$debugfn" "$link"

      continue

    else

      eval linked_$inum=\$f

      echo "file $f has $[$nlinks - 1] other hard links"

    fi

  fi

  echo "extracting debug info from $f"

  id=$(/usr/lib/rpm/debugedit -b "$RPM_BUILD_DIR" -d /usr/src/debug \

			      -i -l "$SOURCEFILE" "$f") || exit

  if [ -z "$id" ]; then

    echo >&2 "*** ${strict_error}: No build ID note found in $f"

    $strict && exit 2

  fi

  # A binary already copied into /usr/lib/debug doesn't get stripped,

  # just has its file names collected and adjusted.

  case "$dn" in

  /usr/lib/debug/*)

    [ -z "$id" ] || make_id_link "$id" "$dn/$(basename $f)"

    continue ;;

  esac

  mkdir -p "${debugdn}"

  if test -w "$f"; then

    strip_to_debug "${debugfn}" "$f"

  else

    chmod u+w "$f"

    strip_to_debug "${debugfn}" "$f"

    chmod u-w "$f"

  fi

  if [ -n "$id" ]; then

    make_id_link "$id" "$dn/$(basename $f)"

    make_id_link "$id" "/usr/lib/debug$dn/$bn" .debug

  fi

done || exit

# For each symlink whose target has a .debug file,

# make a .debug symlink to that file.

find $RPM_BUILD_ROOT ! -path "${debugdir}/*" -type l -print |

while read f

do

  t=$(readlink -m "$f").debug

  f=${f#$RPM_BUILD_ROOT}

  t=${t#$RPM_BUILD_ROOT}

  if [ -f "$debugdir$t" ]; then

    echo "symlinked /usr/lib/debug$t to /usr/lib/debug${f}.debug"

    debug_link "/usr/lib/debug$t" "${f}.debug"

  fi

done

if [ -s "$SOURCEFILE" ]; then

  mkdir -p ${RPM_BUILD_ROOT}/usr/src/debug

  LC_ALL=C sort -z -u $SOURCEFILE | egrep -v -z '(<internal>|<built-in>)$' |

  (cd $RPM_BUILD_DIR; cpio -pd0mL ${RPM_BUILD_ROOT}/usr/src/debug)

  # stupid cpio creates new directories in mode 0700, fixup

  find ${RPM_BUILD_ROOT}/usr/src/debug -type d -print0 |

  xargs --no-run-if-empty -0 chmod a+rx

fi

if [ -d ${RPM_BUILD_ROOT}/usr/lib -o -d ${RPM_BUILD_ROOT}/usr/src ]; then

  gendirs=src

  ((nout > 0)) || gendirs='lib src'

  for d in $gendirs; do

    test ! -d ${RPM_BUILD_ROOT}/usr/$d ||

    (cd ${RPM_BUILD_ROOT}/usr/$d; find debug -type d) |

    sed "s,^,%dir /usr/$d/," >> $LISTFILE

  done

  (cd ${RPM_BUILD_ROOT}/usr

   test ! -d lib/debug || find lib/debug ! -type d

   test ! -d src/debug || find src/debug -mindepth 1 -maxdepth 1

  ) | sed 's,^,/usr/,' >> $LISTFILE

fi

# Append to $1 only the lines from stdin not already in the file.

append_uniq()

{

  fgrep -f "$1" -x -v >> "$1"

}

# Helper to generate list of corresponding .debug files from a file list.

filelist_debugfiles()

{

  local extra="$1"

  shift

  sed 's/^%[a-z0-9_][a-z0-9_]*([^)]*) *//

s/^%[a-z0-9_][a-z0-9_]* *//

/^$/d

'"$extra" "$@"

}

# Write an output debuginfo file list based on given input file lists.

filtered_list()

{

  local out="$1"

  shift

  test $# -gt 0 || return

  fgrep -f <(filelist_debugfiles 's,^.*$,/usr/lib/debug&.debug,' "$@") \

  	-x $LISTFILE >> $out

  sed -n -f <(filelist_debugfiles 's/[\\.*+#]/\\&/g

h

s,^.*$,s# &$##p,p

g

s,^.*$,s# /usr/lib/debug&.debug$##p,p

' "$@") $LINKSFILE | append_uniq "$out"

}

# Write an output debuginfo file list based on an egrep-style regexp.

pattern_list()

{

  local out="$1" ptn="$2"

  test -n "$ptn" || return

  egrep -x -e "$ptn" $LISTFILE >> $out

  sed -n -r "\#^$ptn #s/ .*\$//p" $LINKSFILE | append_uniq "$out"

}

#

# When given multiple -o switches, split up the output as directed.

#

i=0

while ((i < nout)); do

  > ${outs[$i]}

  filtered_list ${outs[$i]} ${lists[$i]}

  pattern_list ${outs[$i]} "${ptns[$i]}"

  fgrep -vx -f ${outs[$i]} $LISTFILE > ${LISTFILE}.new

  mv ${LISTFILE}.new $LISTFILE

  ((++i))

done

if ((nout > 0)); then

  # Now add the right %dir lines to each output list.

  (cd ${RPM_BUILD_ROOT}; find usr/{lib,src}/debug -type d) |

  sed 's#^.*$#\\@^/&/@{h;s@^.*$@%dir /&@;;g;}#' |

  LC_ALL=C sort -ur > ${LISTFILE}.dirs.sed

  i=0

  while ((i < nout)); do

    sed -n -f ${LISTFILE}.dirs.sed ${outs[$i]} | sort -u > ${outs[$i]}.new

    cat ${outs[$i]} >> ${outs[$i]}.new

    mv -f ${outs[$i]}.new ${outs[$i]}

    ((++i))

  done

  sed -n -f ${LISTFILE}.dirs.sed ${LISTFILE} | sort -u > ${LISTFILE}.new

  cat $LISTFILE >> ${LISTFILE}.new

  mv ${LISTFILE}.new $LISTFILE

fi