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Diffstat (limited to 'conform/linknamespace.pl')
| -rw-r--r-- | conform/linknamespace.pl | 233 |
1 files changed, 0 insertions, 233 deletions
diff --git a/conform/linknamespace.pl b/conform/linknamespace.pl deleted file mode 100644 index 3fc6aca621..0000000000 --- a/conform/linknamespace.pl +++ /dev/null @@ -1,233 +0,0 @@ -#!/usr/bin/perl - -# Check that use of symbols declared in a given header does not result -# in any symbols being brought in that are not reserved with external -# linkage for the given standard. - -# Copyright (C) 2014-2018 Free Software Foundation, Inc. -# This file is part of the GNU C Library. - -# The GNU C Library is free software; you can redistribute it and/or -# modify it under the terms of the GNU Lesser General Public -# License as published by the Free Software Foundation; either -# version 2.1 of the License, or (at your option) any later version. - -# The GNU C Library 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 -# Lesser General Public License for more details. - -# You should have received a copy of the GNU Lesser General Public -# License along with the GNU C Library; if not, see -# <http://www.gnu.org/licenses/>. - -use GlibcConform; -use Getopt::Long; - -GetOptions ('header=s' => \$header, 'standard=s' => \$standard, - 'flags=s' => \$flags, 'cc=s' => \$CC, 'tmpdir=s' => \$tmpdir, - 'stdsyms=s' => \$stdsyms_file, 'libsyms=s' => \$libsyms_file, - 'readelf=s' => \$READELF); - -# Load the list of symbols that are OK. -%stdsyms = (); -open (STDSYMS, "<$stdsyms_file") || die ("open $stdsyms_file: $!\n"); -while (<STDSYMS>) { - chomp; - $stdsyms{$_} = 1; -} -close (STDSYMS) || die ("close $stdsyms_file: $!\n"); - -# The following whitelisted symbols are also allowed for now. -# -# * Bug 17576: stdin, stdout, stderr only reserved with external -# linkage when stdio.h included (and possibly not then), not -# generally. -# -# * Bug 18442: re_syntax_options wrongly brought in by regcomp and -# used by re_comp. -# -@whitelist = qw(stdin stdout stderr re_syntax_options); -foreach my $sym (@whitelist) { - $stdsyms{$sym} = 1; -} - -# Return information about GLOBAL and WEAK symbols listed in readelf -# -s output. -sub list_syms { - my ($syms_file) = @_; - open (SYMS, "<$syms_file") || die ("open $syms_file: $!\n"); - my ($file) = $syms_file; - my (@ret) = (); - while (<SYMS>) { - chomp; - if (/^File: (.*)/) { - $file = $1; - $file =~ s|^.*/||; - next; - } - s/^\s*//; - # Architecture-specific st_other bits appear inside [] and disrupt - # the format of readelf output. - s/\[.*?\]//; - my (@fields) = split (/\s+/, $_); - if (@fields < 8) { - next; - } - my ($bind) = $fields[4]; - my ($ndx) = $fields[6]; - my ($sym) = $fields[7]; - if ($bind ne "GLOBAL" && $bind ne "WEAK") { - next; - } - if ($sym !~ /^\w+$/) { - next; - } - push (@ret, [$file, $sym, $bind, $ndx ne "UND"]); - } - close (SYMS) || die ("close $syms_file: $!\n"); - return @ret; -} - -# Load information about GLOBAL and WEAK symbols defined or used in -# the standard libraries. -# Symbols from a given object, except for weak defined symbols. -%seen_syms = (); -# Strong undefined symbols from a given object. -%strong_undef_syms = (); -# Objects defining a given symbol (strongly or weakly). -%sym_objs = (); -@sym_data = list_syms ($libsyms_file); -foreach my $sym (@sym_data) { - my ($file, $name, $bind, $defined) = @$sym; - if ($defined) { - if (!defined ($sym_objs{$name})) { - $sym_objs{$name} = []; - } - push (@{$sym_objs{$name}}, $file); - } - if ($bind eq "GLOBAL" || !$defined) { - if (!defined ($seen_syms{$file})) { - $seen_syms{$file} = []; - } - push (@{$seen_syms{$file}}, $name); - } - if ($bind eq "GLOBAL" && !$defined) { - if (!defined ($strong_undef_syms{$file})) { - $strong_undef_syms{$file} = []; - } - push (@{$strong_undef_syms{$file}}, $name); - } -} - -# Determine what ELF-level symbols are brought in by use of C-level -# symbols declared in the given header. -# -# The rules followed are heuristic and so may produce false positives -# and false negatives. -# -# * All undefined symbols are considered of signficance, but it is -# possible that (a) any standard library definition is weak, so can be -# overridden by the user's definition, and (b) the symbol is only used -# conditionally and not if the program is limited to standard -# functionality. -# -# * If a symbol reference is only brought in by the user using a data -# symbol rather than a function from the standard library, this will -# not be detected. -# -# * If a symbol reference is only brought in by crt*.o or libgcc, this -# will not be detected. -# -# * If a symbol reference is only brought in through __builtin_foo in -# a standard macro being compiled to call foo, this will not be -# detected. -# -# * Header inclusions should be compiled several times with different -# options such as -O2, -D_FORTIFY_SOURCE and -D_FILE_OFFSET_BITS=64 to -# find out what symbols are undefined from such a compilation; this is -# not yet implemented. -# -# * This script finds symbols referenced through use of macros on the -# basis that if a macro calls an internal function, that function must -# also be declared in the header. However, the header might also -# declare implementation-namespace functions that are not called by -# any standard macro in the header, resulting in false positives for -# any symbols brought in only through use of those -# implementation-namespace functions. -# -# * Namespace issues can apply for dynamic linking as well as static -# linking, when a call is from one shared library to another or uses a -# PLT entry for a call within a shared library; such issues are only -# detected by this script if the same namespace issue applies for -# static linking. - -@c_syms = list_exported_functions ("$CC $flags", $standard, $header, $tmpdir); -$cincfile = "$tmpdir/undef-$$.c"; -$cincfile_o = "$tmpdir/undef-$$.o"; -$cincfile_sym = "$tmpdir/undef-$$.sym"; -open (CINCFILE, ">$cincfile") || die ("open $cincfile: $!\n"); -print CINCFILE "#include <$header>\n"; -foreach my $sym (sort @c_syms) { - print CINCFILE "void *__glibc_test_$sym = (void *) &$sym;\n"; -} -close CINCFILE || die ("close $cincfile: $!\n"); -system ("$CC $flags -D_ISOMAC $CFLAGS{$standard} -c $cincfile -o $cincfile_o") - && die ("compiling failed\n"); -system ("LC_ALL=C $READELF -W -s $cincfile_o > $cincfile_sym") - && die ("readelf failed\n"); -@elf_syms = list_syms ($cincfile_sym); -unlink ($cincfile) || die ("unlink $cincfile: $!\n"); -unlink ($cincfile_o) || die ("unlink $cincfile_o: $!\n"); -unlink ($cincfile_sym) || die ("unlink $cincfile_sym: $!\n"); - -%seen_where = (); -%files_seen = (); -%all_undef = (); -%current_undef = (); -foreach my $sym (@elf_syms) { - my ($file, $name, $bind, $defined) = @$sym; - if ($bind eq "GLOBAL" && !$defined) { - $seen_where{$name} = "[initial] $name"; - $all_undef{$name} = "[initial] $name"; - $current_undef{$name} = "[initial] $name"; - } -} - -while (%current_undef) { - %new_undef = (); - foreach my $sym (sort keys %current_undef) { - foreach my $file (@{$sym_objs{$sym}}) { - if (defined ($files_seen{$file})) { - next; - } - $files_seen{$file} = 1; - foreach my $ssym (@{$seen_syms{$file}}) { - if (!defined ($seen_where{$ssym})) { - $seen_where{$ssym} = "$current_undef{$sym} -> [$file] $ssym"; - } - } - foreach my $usym (@{$strong_undef_syms{$file}}) { - if (!defined ($all_undef{$usym})) { - $all_undef{$usym} = "$current_undef{$sym} -> [$file] $usym"; - $new_undef{$usym} = "$current_undef{$sym} -> [$file] $usym"; - } - } - } - } - %current_undef = %new_undef; -} - -$ret = 0; -foreach my $sym (sort keys %seen_where) { - if ($sym =~ /^_/) { - next; - } - if (defined ($stdsyms{$sym})) { - next; - } - print "$seen_where{$sym}\n"; - $ret = 1; -} - -exit $ret; |