Make possible variant SONAMEs and symbol versions

[openssl.git] / util / mkdef.pl

diff --git a/util/mkdef.pl b/util/mkdef.pl
index 20338f57703758b48446061fb73bd896c4efd2ee..1e0da1c87baba4208a9c426d8083905d1e957040 100755 (executable)
--- a/util/mkdef.pl
+++ b/util/mkdef.pl
@@ -53,6 +53,58 @@ use FindBin;
 use lib "$FindBin::Bin/perl";
 use OpenSSL::Glob;
 
+# When building a "variant" shared library, with a custom SONAME, also customize
+# all the symbol versions.  This produces a shared object that can coexist
+# without conflict in the same address space as a default build, or an object
+# with a different variant tag.
+#
+# For example, with a target definition that includes:
+#
+#         shlib_variant => "-opt",
+#
+# we build the following objects:
+#
+# $ perl -le '
+#     for (@ARGV) {
+#         if ($l = readlink) {
+#             printf "%s -> %s\n", $_, $l
+#         } else {
+#             print
+#         }
+#     }' *.so*
+# libcrypto-opt.so.1.1
+# libcrypto.so -> libcrypto-opt.so.1.1
+# libssl-opt.so.1.1
+# libssl.so -> libssl-opt.so.1.1
+#
+# whose SONAMEs and dependencies are:
+#
+# $ for l in *.so; do
+#     echo $l
+#     readelf -d $l | egrep 'SONAME|NEEDED.*(ssl|crypto)'
+#   done
+# libcrypto.so
+#  0x000000000000000e (SONAME)             Library soname: [libcrypto-opt.so.1.1]
+# libssl.so
+#  0x0000000000000001 (NEEDED)             Shared library: [libcrypto-opt.so.1.1]
+#  0x000000000000000e (SONAME)             Library soname: [libssl-opt.so.1.1]
+#
+# We case-fold the variant tag to upper case and replace all non-alnum
+# characters with "_".  This yields the following symbol versions:
+#
+# $ nm libcrypto.so | grep -w A
+# 0000000000000000 A OPENSSL_OPT_1_1_0
+# 0000000000000000 A OPENSSL_OPT_1_1_0a
+# 0000000000000000 A OPENSSL_OPT_1_1_0c
+# 0000000000000000 A OPENSSL_OPT_1_1_0d
+# 0000000000000000 A OPENSSL_OPT_1_1_0f
+# 0000000000000000 A OPENSSL_OPT_1_1_0g
+# $ nm libssl.so | grep -w A
+# 0000000000000000 A OPENSSL_OPT_1_1_0
+# 0000000000000000 A OPENSSL_OPT_1_1_0d
+#
+(my $SO_VARIANT = qq{\U$target{"shlib_variant"}}) =~ s/\W/_/g;
+
 my $debug=0;
 
 my $crypto_num= catfile($config{sourcedir},"util","libcrypto.num");
@@ -1231,13 +1283,13 @@ EOF
                                                if ($symversion ne $prevsymversion) {
                                                        if ($prevsymversion ne "") {
                                                                if ($prevprevsymversion ne "") {
-                                                                       print OUT "} OPENSSL_"
+                                                                       print OUT "} OPENSSL${SO_VARIANT}_"
                                                                                                ."$prevprevsymversion;\n\n";
                                                                } else {
                                                                        print OUT "};\n\n";
                                                                }
                                                        }
-                                                       print OUT "OPENSSL_$symversion {\n    global:\n";
+                                                       print OUT "OPENSSL${SO_VARIANT}_$symversion {\n    global:\n";
                                                        $prevprevsymversion = $prevsymversion;
                                                        $prevsymversion = $symversion;
                                                }
@@ -1286,7 +1338,7 @@ EOF
        } while ($linux && $thisversion ne $currversion);
        if ($linux) {
                if ($prevprevsymversion ne "") {
-                       print OUT "    local: *;\n} OPENSSL_$prevprevsymversion;\n\n";
+                       print OUT "    local: *;\n} OPENSSL${SO_VARIANT}_$prevprevsymversion;\n\n";
                } else {
                        print OUT "    local: *;\n};\n\n";
                }