Add a best effort test to check shared library consistency

Our main development platforms are of the Unix family, which doesn't
have the same strictness regarding a shared library being consistent
with the contents of the ld script (.map file, on Linux and Solaris)
as Windows is with the contents of the .def file or VMS is with the
linker symb_vector option.

To eliminate surprises, we therefore need to make sure to check that
the contents of the .map file is matched with the shared library, at
least to check that the shared library isn't missing any symbols that
should be present.

This test isn't absolutely perfect, as it will only check the symbols
that would be present on Linux / Solaris and will therefore miss those
that would only appear on Windows or VMS.  On the other hand, those
platform specific are few and far apart in time, so it's not likely
they will pose a problem.

Reviewed-by: Matt Caswell <matt@openssl.org>

diff --git a/test/recipes/01-test_symbol_presence.t b/test/recipes/01-test_symbol_presence.t
new file mode 100644 (file)
index 0000000..619519c
--- /dev/null
+++ b/test/recipes/01-test_symbol_presence.t
@@ -0,0 +1,115 @@
+#! /usr/bin/env perl
+# -*- mode: Perl -*-
+# Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
+#
+# Licensed under the OpenSSL license (the "License").  You may not use
+# this file except in compliance with the License.  You can obtain a copy
+# in the file LICENSE in the source distribution or at
+# https://www.openssl.org/source/license.html
+
+use strict;
+use File::Spec::Functions qw(devnull);
+use OpenSSL::Test qw(:DEFAULT srctop_file bldtop_dir bldtop_file);
+use OpenSSL::Test::Utils;
+
+setup("test_symbol_presence");
+
+plan skip_all => "Only useful when building shared libraries"
+    if disabled("shared");
+
+my @libnames = ("crypto", "ssl");
+my $testcount = scalar @libnames;
+
+plan tests => $testcount * 2;
+
+note
+    "NOTE: developper test!  It's possible that it won't run on your\n",
+    "platform, and that's perfectly fine.  This is mainly for developers\n",
+    "on Unix to check that our shared libraries are consistent with the\n",
+    "ordinals (util/*.num in the source tree), something that should be\n",
+    "good enough a check for the other platforms as well.\n";
+
+foreach my $libname (@libnames) {
+ SKIP:
+    {
+        my $shlibpath = bldtop_file("lib" . $libname . ".so");
+        *OSTDERR = *STDERR;
+        *OSTDOUT = *STDOUT;
+        open STDERR, ">", devnull();
+        open STDOUT, ">", devnull();
+        my @nm_lines = map { s|\R$||; $_ } `nm -Pg $shlibpath 2> /dev/null`;
+        close STDERR;
+        close STDOUT;
+        *STDERR = *OSTDERR;
+        *STDOUT = *OSTDOUT;
+        skip "Can't run 'nm -Pg $shlibpath' => $?...  ignoring", 2
+            unless $? == 0;
+
+        my $bldtop = bldtop_dir();
+        my @def_lines;
+        indir $bldtop => sub {
+            my $mkdefpath = srctop_file("util", "mkdef.pl");
+            @def_lines = map { s|\R$||; $_ } `$^X $mkdefpath $libname linux 2> /dev/null`;
+            ok($? == 0, "running 'cd $bldtop; $^X $mkdefpath $libname linux' => $?");
+        }, create => 0, cleanup => 0;
+
+        note "Number of lines in \@nm_lines before massaging: ", scalar @nm_lines;
+        note "Number of lines in \@def_lines before massaging: ", scalar @def_lines;
+
+        # Massage the nm output to only contain defined symbols
+        @nm_lines = sort map { s| .*||; $_ } grep(m|.* [BCDT] .*|, @nm_lines);
+
+        # Massage the mkdef.pl output to only contain global symbols
+        # The output we got is in Unix .map format, which has a global
+        # and a local section.  We're only interested in the global
+        # section.
+        my $in_global = 0;
+        @def_lines =
+            sort
+            map { s|;||; s|\s+||g; $_ }
+            grep { $in_global = 1 if m|global:|;
+                   $in_global = 0 if m|local:|;
+                   $in_global && m|;|; } @def_lines;
+
+        note "Number of lines in \@nm_lines after massaging: ", scalar @nm_lines;
+        note "Number of lines in \@def_lines after massaging: ", scalar @def_lines;
+
+        # Maintain lists of symbols that are missing in the shared library,
+        # or that are extra.
+        my @missing = ();
+        my @extra = ();
+
+        while (scalar @nm_lines || scalar @def_lines) {
+            my $nm_first = $nm_lines[0];
+            my $def_first = $def_lines[0];
+
+            if (!defined($nm_first)) {
+                push @missing, shift @def_lines;
+            } elsif (!defined($def_first)) {
+                push @extra, shift @nm_lines;
+            } elsif ($nm_first gt $def_first) {
+                push @missing, shift @def_lines;
+            } elsif ($nm_first lt $def_first) {
+                push @extra, shift @nm_lines;
+            } else {
+                shift @def_lines;
+                shift @nm_lines;
+            }
+        }
+
+        if (scalar @missing) {
+            note "The following symbols are missing in lib$libname.so:";
+            foreach (@missing) {
+                note "  $_";
+            }
+        }
+        if (scalar @extra) {
+            note "The following symbols are extra in lib$libname.so:";
+            foreach (@extra) {
+                note "  $_";
+            }
+        }
+        ok(scalar @missing == 0,
+           "check that there are no missing symbols in lib$libname.so");
+    }
+}