#!/bin/bash

# Wrapper script for find-debuginfo.sh

#

# Usage:

#  wrap-find-debuginfo.sh SYSROOT-PATH SCRIPT-PATH SCRIPT-ARGS...

#

# The wrapper saves the original version of ld.so found in SYSROOT-PATH,

# invokes SCRIPT-PATH with SCRIPT-ARGS, and then restores the

# LDSO-PATH file, followed by note merging and DWZ compression.

# As a result, ld.so has (mostly) unchanged debuginfo even

# after debuginfo extraction.

#

# For libc.so.6, a set of strategic symbols is preserved in .symtab

# that are frequently used in valgrind suppressions and elsewhere.

set -ex

ldso_tmp="$(mktemp)"

libc_tmp="$(mktemp)"

# Prefer a separately installed debugedit over the RPM-integrated one.

if command -v debugedit >/dev/null ; then

    debugedit=debugedit

else

    debugedit=/usr/lib/rpm/debugedit

fi

cleanup () {

    rm -f "$ldso_tmp" "$libc_tmp"

}

trap cleanup 0

sysroot_path="$1"

shift

script_path="$1"

shift

# See ldso_path setting in glibc.spec.

ldso_path=

for ldso_candidate in `find "$sysroot_path" -regextype posix-extended \

  -regex '.*/ld(-.*|64|)\.so\.[0-9]+$' -type f` ; do

    if test -z "$ldso_path" ; then

	ldso_path="$ldso_candidate"

    else

	echo "error: multiple ld.so candidates: $ldso_path, $ldso_candidate"

	exit 1

    fi

done

# libc.so.6 always uses this name, so it is simpler to locate.

libc_path=

for libc_candidate in `find "$sysroot_path" -name libc.so.6`; do

    if test -z "$libc_path" ; then

	libc_path="$libc_candidate"

    else

	echo "error: multiple libc.so.6 candidates: $libc_path, $libc_candidate"

	exit 1

    fi

done

# Preserve the original files.

cp "$ldso_path" "$ldso_tmp"

cp "$libc_path" "$libc_tmp"

# Run the debuginfo extraction.

"$script_path" "$@"

# Restore the original files.

cp "$ldso_tmp" "$ldso_path"

cp "$libc_tmp" "$libc_path"

# Reduce the size of notes.  Primarily for annobin.

objcopy --merge-notes "$ldso_path"

objcopy --merge-notes "$libc_path"

# libc.so.6: Reduce to valuable symbols.  Eliminate file symbols,

# annobin symbols, and symbols used by the glibc build to implement

# hidden aliases (__EI_*).  We would also like to remove __GI_*

# symbols, but even listing them explicitly (as in -K __GI_strlen)

# still causes strip to remove them, so there is no filtering of

# __GI_* here.  (Debuginfo is gone after this, so no need to optimize

# it.)

strip -w \

    -K '*' \

    -K '!*.c' \

    -K '!*.os' \

    -K '!.annobin_*' \

    -K '!__EI_*' \

    -K '!__PRETTY_FUNCTION__*' \

    "$libc_path"

# ld.so: Rewrite the source file paths to match the extracted

# locations.  First compute the arguments for invoking debugedit.

# See find-debuginfo.sh.

debug_dest_name="/usr/src/debug"

last_arg=

while true ; do

    arg="$1"

    shift || break

    case "$arg" in

	(--unique-debug-src-base)

	    debug_dest_name="/usr/src/debug/$1"

	    shift

	    ;;

	(-*)

	    ;;

	(*)

	    last_arg="$arg"

	    ;;

    esac

done

debug_base_name=${last_arg:-$RPM_BUILD_ROOT}

$debugedit -b "$debug_base_name" -d "$debug_dest_name" -n $ldso_path

# Apply single-file DWARF optimization.

dwz $ldso_path