Feature: Allow building shared libraries with SONAME

[susnux]

For packaging for openSUSE it was needed to add a SONAME to the library, but I think this could be useful for other users as well.
To support versioned SONAME, I had to patch the project like this:

diff -Nur mruby-3.0.0/build_config/host-shared.rb new/build_config/host-shared.rb
--- mruby-3.0.0/build_config/host-shared.rb	2021-03-05 09:07:35.000000000 +0100
+++ new/build_config/host-shared.rb	2022-02-21 12:59:46.926385435 +0100
@@ -18,12 +18,12 @@
 
   conf.archiver do |archiver|
     archiver.command = 'gcc'
-    archiver.archive_options = '-shared -o %{outfile} %{objs}'
+    archiver.archive_options = '-shared -Wl,-soname,%{filename} -o %{outfile} %{objs}'
   end
 
   # file extensions
   conf.exts do |exts|
-     exts.library = '.so'
+     exts.library = '.so.%{version}'
   end
 
   # file separator
diff -Nur mruby-3.0.0/lib/mruby/build/command.rb new/lib/mruby/build/command.rb
--- mruby-3.0.0/lib/mruby/build/command.rb	2021-03-05 09:07:35.000000000 +0100
+++ new/lib/mruby/build/command.rb	2022-02-21 13:10:29.627639126 +0100
@@ -4,7 +4,7 @@
   class Command
     include Rake::DSL
     extend Forwardable
-    def_delegators :@build, :filename, :objfile, :libfile, :exefile
+    def_delegators :@build, :filename, :realname, :objfile, :libfile, :exefile
     attr_accessor :build, :command
 
     def initialize(build)
@@ -234,7 +234,7 @@
     def run(outfile, objfiles)
       mkdir_p File.dirname(outfile)
       _pp "AR", outfile.relative_path
-      _run archive_options, { :outfile => filename(outfile), :objs => filename(objfiles).map{|f| %Q["#{f}"]}.join(' ') }
+      _run archive_options, { :outfile => filename(outfile), :filename => realname(outfile), :objs => filename(objfiles).map{|f| %Q["#{f}"]}.join(' ') }
     end
   end
 
diff -Nur mruby-3.0.0/lib/mruby/build.rb new/lib/mruby/build.rb
--- mruby-3.0.0/lib/mruby/build.rb	2021-03-05 09:07:35.000000000 +0100
+++ new/lib/mruby/build.rb	2022-02-21 12:59:29.906251522 +0100
@@ -6,6 +6,7 @@
   autoload :Gem, "mruby/gem"
   autoload :Lockfile, "mruby/lockfile"
   autoload :Presym, "mruby/presym"
+  autoload :Source, 'mruby/source'
 
   class << self
     def targets
@@ -380,6 +381,10 @@
       end
     end
 
+    def realname(name)
+      filename(name).rpartition(file_separator)[-1]
+    end
+
     def exefile(name)
       if name.is_a?(Array)
         name.flatten.map { |n| exefile(n) }
@@ -403,7 +408,7 @@
       if name.is_a?(Array)
         name.flatten.map { |n| libfile(n) }
       else
-        "#{name}#{exts.library}"
+        "#{name}#{exts.library}" % {:version => MRuby::Source::MRUBY_VERSION}
       end
     end
 

[matz]

Can you make this patch a pull request?