Configure: Read in extra information to help create shared libraries

This will replace the use of Makefile.shared

This also means a small adjustment on how the attributes dso_cflags,
dso_cxxflags and dso_lflags are treated.  They were previously treated
as an extension to shared_cflag, shared_cxxflag and shared_ldflag, but
they should really be regarded as alternatives instead, for example
for darwin, where -dynamiclib is used for shared libraries and -bundle
for DSOs.

We take the opportunity to clean out things that are redundant or
otherwise superfluous (for example the check of GNU ld on platforms
where it never existed).
Reviewed-by: NAndy Polyakov <appro@openssl.org>
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4840)

Configurations/shared-info.pl

+#! /usr/bin/env perl
+# -*- mode: perl; -*-
+# Copyright 2016-2017 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
+
+# This is a collection of extra attributes to be used as input for creating
+# shared libraries, currently on any Unix variant, including Unix like
+# environments on Windows.
+
+sub detect_gnu_ld {
+    my @lines =
+        `$config{cross_compile_prefix}$target{cc} -Wl,-V /dev/null 2>&1`;
+    return grep /^GNU ld/, @lines;
+}
+sub detect_gnu_cc {
+    my @lines =
+        `$config{cross_compile_prefix}$target{cc} -v 2>&1`;
+    return grep /gcc/, @lines;
+}
+
+my %shared_info;
+%shared_info = (
+    'gnu-shared' => {
+        shared_ldflag         => '-shared -Wl,-Bsymbolic',
+        shared_sonameflag     => '-Wl,-soname=',
+    },
+    'linux-shared' => sub {
+        return {
+            %{$shared_info{'gnu-shared'}},
+            shared_defflag    => '-Wl,--version-script=',
+        };
+    },
+    'bsd-gcc-shared' => sub { return $shared_info{'linux-shared'}; },
+    'bsd-shared' => sub {
+        return $shared_info{'gnu-shared'} if detect_gnu_ld();
+        return {
+            shared_ldflag     => '-shared -nostdlib',
+        };
+    },
+    'darwin-shared' => {
+        dso_lflags            => '-bundle',
+        shared_ldflag         => '-dynamiclib -current_version $(SHLIB_VERSION_NUMBER) -compatibility_version $(SHLIB_VERSION_NUMBER)',
+        shared_sonameflag     => '-install_name $(INSTALLTOP)/$(LIBDIR)/',
+    },
+    'cygwin-shared' => {
+        shared_ldflag         => '-shared -Wl,--enable-auto-image-base',
+        shared_impflag        => '-Wl,--out-implib=',
+    },
+    'mingw-shared' => sub {
+        return {
+            %{$shared_info{'cygwin-shared'}},
+            # def_flag made to empty string so  it still generates
+            # something
+            shared_defflag    => '',
+        };
+    },
+    'alpha-osf1-shared' => sub {
+        return $shared_info{'gnu-shared'} if detect_gnu_ld();
+        return {
+            dso_lflags        => '-shared -Wl,-Bsymbolic',
+            shared_ldflag     => '-shared -Wl,-Bsymbolic -set_version $(SHLIB_VERSION_NUMBER)',
+        };
+    },
+    'solaris-shared' => {
+        shared_ldflag     => '-Wl,-Bsymbolic',
+        shared_defflag    => '-Wl,-M,',
+    },
+    'svr3-shared' => sub {
+        return $shared_info{'gnu-shared'} if detect_gnu_ld();
+        return {
+            shared_ldflag     => '-G',
+            shared_sonameflag => '-h ',
+        };
+    },
+    'svr5-shared' => sub {
+        return $shared_info{'gnu-shared'} if detect_gnu_ld();
+        return {
+            shared_ldflag     => detect_gnu_cc() ? '-shared' : '-G',
+            shared_sonameflag => '-h ',
+        };
+    },
+    'irix-shared' => sub {
+        return $shared_info{'gnu-shared'} if detect_gnu_ld();
+        return {
+            shared_ldflag     => '-shared -Wl,-Bsymbolic',
+            shared_sonameflag => '-Wl,-soname=',
+        };
+    },
+    'hpux-shared' => {
+        bin_lflags        => '-Wl,+s,+cdp,../:,+cdp,./:',
+        shared_ldflag     => '-Wl,-B,symbolic,+vnocompatwarnings,-z,+s,+cdp,../:,+cdp,./:',
+        shared_sonameflag => '-Wl,+h,',
+    },
+    'aix-shared' => {
+        bin_lflags            => '-Wl,-bsvr4',
+        shared_ldflag         => '-Wl,-bexpall,-bnolibpath,-bM:SRE',
+    },
+);

Configurations/unix-Makefile.tmpl

@@ -195,11 +195,12 @@ EX_LIBS= {- $target{ex_libs} -} {- $config{ex_libs} -}
 LIB_CFLAGS={- $target{shared_cflag} || "" -}
 LIB_CXXFLAGS={- $target{shared_cxxflag} || "" -}
 LIB_LDFLAGS={- $target{shared_ldflag}." ".$config{shared_ldflag} -}
-DSO_CFLAGS={- $target{shared_cflag} || "" -}
-DSO_CXXFLAGS={- $target{shared_cxxflag} || "" -}
-DSO_LDFLAGS=$(LIB_LDFLAGS)
-BIN_CFLAGS={- $target{bin_cflags} -}
-BIN_CXXFLAGS={- $target{bin_cxxflag} || "" -}
+DSO_CFLAGS={- $target{dso_cflags} || "" -}
+DSO_CXXFLAGS={- $target{dso_cxxflags} || "" -}
+DSO_LDFLAGS={- $target{dso_lflags} || "" -}
+BIN_CFLAGS={- $target{bin_cflags} || "" -}
+BIN_CXXFLAGS={- $target{bin_cxxflags} || "" -}
+BIN_LDFLAGS={- $target{bin_lflags} || "" -}
 
 PERL={- $config{perl} -}
 

Configurations/windows-makefile.tmpl

@@ -169,8 +169,8 @@ LDOUTFLAG={- $target{loutflag} || "/out:" -}$(OSSL_EMPTY)
 EX_LIBS={- $target{ex_libs} -}
 LIB_CFLAGS={- join(" ", $target{lib_cflags}, $target{shared_cflag}) || "" -}
 LIB_LDFLAGS={- $target{shared_ldflag} || "" -}
-DSO_CFLAGS={- join(" ", $target{dso_cflags}, $target{shared_cflag}) || "" -}
-DSO_LDFLAGS={- join(" ", $target{dso_lflags}, $target{shared_ldflag}) || "" -}
+DSO_CFLAGS={- $target{dso_cflags} || "" -}
+DSO_LDFLAGS={- $target{dso_ldflag} || "" -}
 BIN_CFLAGS={- $target{bin_cflags} -}
 BIN_LDFLAGS={- $target{bin_lflags} -}
 

Configure

@@ -879,9 +879,48 @@ my %target = resolve_config($target);
 
 &usage if (!%target || $target{template});
 
+%target = ( %{$table{DEFAULTS}}, %target );
+
+# Make the flags to build DSOs the same as for shared libraries unless they
+# are already defined
+$target{dso_cflags} = $target{shared_cflag} unless defined $target{dso_cflags};
+$target{dso_cxxflags} = $target{shared_cxxflag} unless defined $target{dso_cxxflags};
+$target{dso_lflags} = $target{shared_ldflag} unless defined $target{dso_lflags};
+{
+    my $shared_info_pl =
+        catfile(dirname($0), "Configurations", "shared-info.pl");
+    my %shared_info = read_eval_file($shared_info_pl);
+    push @{$target{_conf_fname_int}}, $shared_info_pl;
+    my $si = $target{shared_target};
+    while (ref $si ne "HASH") {
+        last if ! defined $si;
+        if (ref $si eq "CODE") {
+            $si = $si->();
+        } else {
+            $si = $shared_info{$si};
+        }
+    }
+
+    # Some of the 'shared_target' values don't have any entried in
+    # %shared_info.  That's perfectly fine, AS LONG AS the build file
+    # template knows how to handle this.  That is currently the case for
+    # Windows and VMS.
+    if (defined $si) {
+        # Just as above, copy certain shared_* attributes to the corresponding
+        # dso_ attribute unless the latter is already defined
+        $si->{dso_cflags} = $si->{shared_cflag} unless defined $si->{dso_cflags};
+        $si->{dso_cxxflags} = $si->{shared_cxxflag} unless defined $si->{dso_cxxflags};
+        $si->{dso_lflags} = $si->{shared_ldflag} unless defined $si->{dso_lflags};
+        foreach (sort keys %$si) {
+            $target{$_} = defined $target{$_}
+                ? add($si->{$_})->($target{$_})
+                : $si->{$_};
+        }
+    }
+}
+
 my %conf_files = map { $_ => 1 } (@{$target{_conf_fname_int}});
 $config{conf_files} = [ sort keys %conf_files ];
-%target = ( %{$table{DEFAULTS}}, %target );
 
 foreach my $feature (@{$target{disable}}) {
     if (exists $deprecated_disablables{$feature}) {
@@ -1163,8 +1202,11 @@ unless ($disabled{"fuzz-libfuzzer"} && $disabled{"fuzz-afl"}
 # This saves the build files from having to check
 if ($disabled{pic})
 	{
-	$target{shared_cflag} = $target{shared_ldflag} =
-		$target{shared_rcflag} = "";
+	foreach (qw(shared_cflag shared_cxxflag shared_ldflag
+		    dso_cflags dso_cxxflags dso_lflags))
+		{
+		$target{$_} = "";
+		}
 	}
 else
 	{