mkmf.rb: sort lists of source and object files

* lib/mkmf.rb (create_makefile): sort lists of source and object
  files in generated Makefile, unless given by extconf.rb.
  [Fix GH-1367]

Without sorting the list of object files explicitely, its order is
indeterministic, because readdir() is also not deterministic.
When the list of object files varies between builds, they are
linked in a different order, which results in an unreproducible
build.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55265 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 13 insertions, 3 deletions

diff --git a/ChangeLog b/ChangeLog
index 7f45ae2419..6e7d299f0b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Fri Jun  3 17:44:25 2016  Reiner Herrmann  <reiner@reiner-h.de>
+
+	* lib/mkmf.rb (create_makefile): sort lists of source and object
+	  files in generated Makefile, unless given by extconf.rb.
+	  [Fix GH-1367]
+
 Thu Jun  2 21:18:10 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* win32/win32.c (get_special_folder): use SHGetPathFromIDListEx if
diff --git a/lib/mkmf.rb b/lib/mkmf.rb
index eee42d0e51..53aea8cecd 100644
--- a/lib/mkmf.rb
+++ b/lib/mkmf.rb
@@ -2205,11 +2205,15 @@ RULES
     RbConfig.expand(srcdir = srcprefix.dup)
 
     ext = ".#{$OBJEXT}"
-    orig_srcs = Dir[File.join(srcdir, "*.{#{SRC_EXT.join(%q{,})}}")]
+    orig_srcs = Dir[File.join(srcdir, "*.{#{SRC_EXT.join(%q{,})}}")].sort
     if not $objs
       srcs = $srcs || orig_srcs
-      objs = srcs.inject(Hash.new {[]}) {|h, f| h[File.basename(f, ".*") << ext] <<= f; h}
-      $objs = objs.keys
+      $objs = []
+      objs = srcs.inject(Hash.new {[]}) {|h, f|
+        h.key?(o = File.basename(f, ".*") << ext) or $objs << o
+        h[o] <<= f
+        h
+      }
       unless objs.delete_if {|b, f| f.size == 1}.empty?
         dups = objs.sort.map {|b, f|
           "#{b[/.*\./]}{#{f.collect {|n| n[/([^.]+)\z/]}.join(',')}}"