# Generate an ELF symbol version map a-la Solaris and GNU ld.

# Generate an ELF symbol version map a-la Solaris and GNU ld.
# Copyright (C) 2007-2024 Free Software Foundation, Inc.
# Contributed by Richard Henderson <[email protected]>
#
# This file is part of GCC.
#
# GCC is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free
# Software Foundation; either version 3, or (at your option) any later
# version.
#
# GCC is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
# License for more details.
#
# You should have received a copy of the GNU General Public License
# along with GCC; see the file COPYING3. If not see
# <http://www.gnu.org/licenses/>.

BEGIN {
state = "nm";
sawsymbol = 0;
if (leading_underscore)
prefix = "_";
else
prefix = "";
}

# Remove comment and blank lines.
/^ *#/ || /^ *$/ {
next;
}

# We begin with nm input. Collect the set of symbols that are present
# so that we cannot emit them into the final version script -- Solaris
# complains at us if we do.

state == "nm" && /^%%/ {
state = "ver";
next;
}

state == "nm" && ($1 == "U" || $2 == "U") {
next;
}

state == "nm" && NF == 3 {
split ($3, s, "@")
if (skip_underscore && substr(s[1], 1, 1) == "_")
symname = substr(s[1], 2);
else
symname = s[1];
def[symname] = 1;
sawsymbol = 1;
next;
}

state == "nm" {
next;
}

# Now we process a simplified variant of the Solaris symbol version
# script. We have one symbol per line, no semicolons, simple markers
# for beginning and ending each section, and %inherit markers for
# describing version inheritance. A symbol may appear in more than
# one symbol version, and the last seen takes effect.
# The magic version name '%exclude' causes all the symbols given that
# version to be dropped from the output (unless a later version overrides).

NF == 3 && $1 == "%inherit" {
inherit[$2] = $3;
next;
}

NF == 2 && $2 == "{" {
if ($1 != "%exclude")
libs[$1] = 1;
thislib = $1;
next;
}

$1 == "}" {
thislib = "";
next;
}

{
sym = prefix $1;
symbols[sym] = 1
if (thislib != "%exclude")
ver[sym, thislib] = 1;
else {
for (l in libs)
ver[sym, l] = 0;
}
next;
}

END {
if (!sawsymbol)
{
print "No symbols seen -- broken or mis-installed nm?" | "cat 1>&2";
exit 1;
}
for (l in libs)
output(l);
}

function output(lib) {
if (done[lib])
return;
done[lib] = 1;
if (inherit[lib])
output(inherit[lib]);

empty=1
for (sym in symbols)
if ((ver[sym, lib] != 0) && (sym in def))
{
if (empty)
{
printf("%s {\n", lib);
printf(" global:\n");
empty = 0;
}
printf("\t%s;\n", sym);
}

if (empty)
{
for (l in libs)
if (inherit[l] == lib)
inherit[l] = inherit[lib];
}
else if (inherit[lib])
printf("} %s;\n", inherit[lib]);
else
printf ("\n local:\n\t*;\n};\n");
}