Convert linknamespace tests from Perl to Python.

This patch replaces conform/linknamespace.pl with a new
conform/linknamespace.py, so continuing the consolidation on Python
instead of Perl for miscellaneous scripts used in building and testing
glibc.  The new script follows the same logic as the old one; as a
recently-added script, there were no major cleanups to be made in the
course of the language conversion.

Tested for x86_64, and with build-many-glibcs.py.  For x86_64 I also
tested that if the Perl and Python scripts were made to print all the
symbols in seen_where and the paths of symbol references by which
those symbols were linked in, even when those symbols were OK,
identical symbol lists appeared in the output with both versions of
the script (the differences in linknamespace.out files were only in
paths to temporary files in diagnostics for e.g. deprecated functions,
and error output for the expected compilation failures when testing
ndbm.h and varargs.h).

	* conform/linknamespace.py: New file.
	* conform/linknamespace.pl: Remove file.
	* conform/Makefile ($(linknamespace-header-tests)): Use
	linknamespace.py instead of linknamespace.pl.  Do not use --tmpdir
	option.

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;