#!/bin/bash

# get a list of all symbols - YOU MUST RUN THIS SCRIPT WITH THE LATEST VERSIONS OF GLIBC
# currently blacklists all newer than 2.3.0

if [ -e syms ]; then rm syms; fi
if [ -e allsym ]; then rm allsym; fi

#host=`gcc -v 2>&1 | grep 'Target:' | sed 's/Target: //'`
host=x86_64-linux-gnu
for f in /lib/* /lib/$host/*; do
    if [ ! -f $f ]; then continue; fi
    readelf -s --wide $f >>syms
    objdump -T $f | grep "GLIBC_" | sed 's/\(.*\)GLIBC_//; s/)//' | grep -v PRIVATE | column -t >>allsym
done


# get a list of all symbol versions only available in 2.3+
grep @GLIBC_ syms | awk ' { print $8 } ' | sed 's/@\+/ /; /GLIBC_P/d; s/GLIBC_//' | awk ' { split($2, Ver, "."); if (Ver[2] > 3) print $1 " " $2 } ' | column -t >glibc2.4.syms

# select the symbols that already existed, but were obsoleted by 2.2+ versions
cat glibc2.4.syms | awk '{print $1}' | while read; do grep $REPLY allsym; done | sed '/2\.4/d' >syms-to-header

# select the latest symbols of that set
# build a header from them
cat syms-to-header | awk '{print $2 "  " $1 }' | sort -V | uniq >output
cat glibc2.4.syms | sort -V | uniq  >> output

cat output | sort | uniq | awk '{print $2 "   " $1}' | sort -k2,1 | awk '{ split($1, Ver, "."); if (Ver[2] <= 3) print $1 "  " $2 }' | column -t | sort -k2 | uniq -f1 >output2

# output the symbols that are brand new to 2.3+, ie not the ones that had earlier versions
cat glibc2.4.syms | awk '{ print $1 }' | while read; do if ! grep "$REPLY" output2 >/dev/null; then echo "DONT_USE_THIS_SYMBOL  $REPLY" >>output2; fi; done;

cat output2 | column -t | awk '{ print "__asm__(\".symver " $2 "," $2 "@GLIBC_" $1 "\");" }' > output

# now remove dl_iterate_phdr as it's weak anyway (we should probably do this for all weak syms)
cat output | sed 's/__asm__("\.symver dl_iterate_phdr.*//' >output2

cat <<EOF >apsymbols.h.x86_64
/* apbuild embedded metadata */
#define APBUILD_NOTE_METADATA(s) \
  __asm__(".section .metadata, \"MS\", @note, 1\n\t.string \"" s "\"\n\t.previous\n\t")

#ifdef APBUILD_VERSION
APBUILD_NOTE_METADATA("apbuild.version=" APBUILD_VERSION);
#endif

/* apbuild generated symbol exclusion list */
EOF
cat output2 >> apsymbols.h.x86_64
rm output2