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glibc/scripts/versions.awk

234 lines
6.7 KiB
Awk

# Combine version map fragments into version scripts for our shared objects.
# Copyright (C) 1998-2024 Free Software Foundation, Inc.
# This script expects the following variables to be defined:
# defsfile name of Versions.def file
# buildroot name of build directory with trailing slash
# move_if_change move-if-change command
# Read definitions for the versions.
BEGIN {
lossage = 0;
nlibs=0;
while (getline < defsfile) {
if (/^[a-zA-Z0-9_.]+ \{/) {
libs[$1] = 1;
curlib = $1;
while (getline < defsfile && ! /^}/) {
if ($2 == "=") {
renamed[curlib "::" $1] = $3;
}
else
versions[curlib "::" $1] = 1;
}
}
}
close(defsfile);
tmpfile = buildroot "Versions.tmp";
# POSIX sort needed.
sort = "sort -t. -k 1,1 -k 2n,2n -k 3 > " tmpfile;
}
# GNU awk does not implement the ord and chr functions.
# <https://www.gnu.org/software/gawk/manual/html_node/Ordinal-Functions.html>
# says that they are "written very nicely", using code similar to what
# is included here.
function chr(c) {
return sprintf("%c", c)
}
BEGIN {
for (c = 1; c < 127; c++) {
ord_table[chr(c)] = c;
}
}
function ord(c) {
if (ord_table[c]) {
return ord_table[c];
} else {
printf("Invalid character reference: '%c'\n", c) > "/dev/stderr";
++lossage;
}
}
# Remove comment lines.
/^ *#/ {
next;
}
# This matches the beginning of the version information for a new library.
/^[a-zA-Z0-9_.]+/ {
actlib = $1;
if (!libs[$1]) {
printf("no versions defined for %s\n", $1) > "/dev/stderr";
++lossage;
}
next;
}
# This matches the beginning of a new version for the current library.
/^ [A-Za-z_]/ {
if (renamed[actlib "::" $1])
actver = renamed[actlib "::" $1];
else if (!versions[actlib "::" $1] && $1 != "GLIBC_PRIVATE") {
printf("version %s not defined for %s\n", $1, actlib) > "/dev/stderr";
++lossage;
}
else
actver = $1;
next;
}
# This matches lines with names to be added to the current version in the
# current library. This is the only place where we print something to
# the intermediate file.
/^ / {
sortver=actver
# Ensure GLIBC_ versions come always first
sub(/^GLIBC_/," GLIBC_",sortver)
printf("%s %s %s\n", actlib, sortver, $0) | sort;
}
# Some targets do not set the ABI baseline for libdl. As a result,
# symbols originally in libdl need to be moved under historic symbol
# versions, without altering the baseline version for libc itself.
/^ *!libc_pre_versions/ {
libc_pre_versions_active = 1;
}
function libc_pre_versions() {
# No local: * here, so that we do not have to update this script
# if symbols are moved into libc. The abilist files and the other
# targets (with a real GLIBC_2.0 baseline) provide testing
# coverage.
printf("\
GLIBC_2.0 {\n\
};\n\
GLIBC_2.1 {\n\
} GLIBC_2.0;\n\
") > outfile;
return "GLIBC_2.1";
}
function closeversion(name, oldname) {
printf(" local:\n *;\n") > outfile;
# This version inherits from the last one only if they
# have the same nonnumeric prefix, i.e. GLIBC_x.y and GLIBC_x.z
# or FOO_x and FOO_y but not GLIBC_x and FOO_y.
pfx = oldname;
sub(/[0-9.]+/,".+",pfx);
if (oldname == "" || name !~ pfx) print "};" > outfile;
else printf("} %s;\n", oldname) > outfile;
}
function close_and_move(name, real_name) {
close(name);
system(move_if_change " " name " " real_name " >&2");
}
# ELF hash, for use with symbol versions.
function elf_hash(s, i, acc) {
acc = 0;
for (i = 1; i <= length(s); ++i) {
acc = and(lshift(acc, 4) + ord(substr(s, i, 1)), 0xffffffff);
top = and(acc, 0xf0000000);
acc = and(xor(acc, rshift(top, 24)), compl(top));
}
return acc;
}
# Now print the accumulated information.
END {
close(sort);
if (lossage) {
system("rm -f " tmpfile);
exit 1;
}
oldlib = "";
oldver = "";
real_first_ver_header = buildroot "first-versions.h"
first_ver_header = real_first_ver_header "T"
printf("#ifndef _FIRST_VERSIONS_H\n") > first_ver_header;
printf("#define _FIRST_VERSIONS_H\n") > first_ver_header;
real_ldbl_compat_header = buildroot "ldbl-compat-choose.h"
ldbl_compat_header = real_ldbl_compat_header "T"
printf("#ifndef _LDBL_COMPAT_CHOOSE_H\n") > ldbl_compat_header;
printf("#define _LDBL_COMPAT_CHOOSE_H\n") > ldbl_compat_header;
printf("#ifndef LONG_DOUBLE_COMPAT\n") > ldbl_compat_header;
printf("# error LONG_DOUBLE_COMPAT not defined\n") > ldbl_compat_header;
printf("#endif\n") > ldbl_compat_header;
printf("version-maps =");
while (getline < tmpfile) {
if ($1 != oldlib) {
if (oldlib != "") {
closeversion(oldver, veryoldver);
oldver = "";
close_and_move(outfile, real_outfile);
}
oldlib = $1;
real_outfile = buildroot oldlib ".map";
outfile = real_outfile "T";
if ($1 == "libc" && libc_pre_versions_active) {
veryoldver = libc_pre_versions();
} else {
veryoldver = "";
}
printf(" %s.map", oldlib);
}
if ($2 != oldver) {
if (oldver != "") {
closeversion(oldver, veryoldver);
veryoldver = oldver;
}
oldver = $2;
# Skip the placeholder symbol used only for empty version map.
if ($3 == "__placeholder_only_for_empty_version_map;") {
printf("%s {\n", $2) > outfile;
continue;
}
printf("%s {\n global:\n", $2) > outfile;
}
printf(" ") > outfile;
for (n = 3; n <= NF; ++n) {
printf(" %s", $n) > outfile;
sym = $n;
sub(";", "", sym);
first_ver_macro = "FIRST_VERSION_" oldlib "_" sym;
if (!(first_ver_macro in first_ver_seen) \
&& oldver ~ "^GLIBC_[0-9]" \
&& sym ~ "^[A-Za-z0-9_]*$") {
ver_val = oldver;
printf("#define %s_STRING \"%s\"\n", first_ver_macro, ver_val) > first_ver_header;
printf("#define %s_HASH 0x%x\n", first_ver_macro, elf_hash(ver_val)) > first_ver_header;
gsub("\\.", "_", ver_val);
printf("#define %s %s\n", first_ver_macro, ver_val) > first_ver_header;
first_ver_seen[first_ver_macro] = 1;
if (oldlib == "libc" || oldlib == "libm") {
printf("#if LONG_DOUBLE_COMPAT (%s, %s)\n",
oldlib, ver_val) > ldbl_compat_header;
printf("# define LONG_DOUBLE_COMPAT_CHOOSE_%s_%s(a, b) a\n",
oldlib, sym) > ldbl_compat_header;
printf("#else\n") > ldbl_compat_header;
printf("# define LONG_DOUBLE_COMPAT_CHOOSE_%s_%s(a, b) b\n",
oldlib, sym) > ldbl_compat_header;
printf("#endif\n") > ldbl_compat_header;
}
}
}
printf("\n") > outfile;
}
printf("\n");
printf("#endif /* first-versions.h */\n") > first_ver_header;
printf("#endif /* ldbl-compat-choose.h */\n") > ldbl_compat_header;
closeversion(oldver, veryoldver);
close_and_move(outfile, real_outfile);
close_and_move(first_ver_header, real_first_ver_header);
close_and_move(ldbl_compat_header, real_ldbl_compat_header);
#system("rm -f " tmpfile);
}