* ext/dbm/extconf.rb: detect gdbm_version in libgdbm.

* ext/dbm/dbm.c: make DBM::VERSION more informative for gdbm, qdbm and
  Berkeley DB 1.x.  [ruby-dev:44944]



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@33959 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 33 insertions, 0 deletions

diff --git a/ext/dbm/extconf.rb b/ext/dbm/extconf.rb
index ba5cfe4243..6a4b8c069d 100644
--- a/ext/dbm/extconf.rb
+++ b/ext/dbm/extconf.rb
@@ -40,6 +40,32 @@ def headers.db_check(db, hdr)
   result
 end
 
+def have_libvar(var, headers = nil, opt = "", &b)
+  checking_for checking_message([*var].compact.join(' '), headers, opt) do
+    try_libvar(var, headers, opt, &b)
+  end
+end
+
+def try_libvar(var, headers = nil, opt = "", &b)
+  var, type = *var
+  if try_link(<<"SRC", opt, &b)
+#{cpp_include(headers)}
+/*top*/
+int main(int argc, char *argv[]) {
+  typedef #{type || 'int'} conftest_type;
+  extern conftest_type #{var};
+  conftest_type *conftest_var = &#{var};
+  return 0;
+}
+SRC
+    $defs.push(format("-DHAVE_LIBVAR_%s", var.tr_cpp))
+    true
+  else
+    false
+  end
+end
+
+
 def headers.db_check2(db, hdr)
   hsearch = nil
 
@@ -54,6 +80,13 @@ def headers.db_check2(db, hdr)
      (db == 'libc' ? have_func('dbm_open("", 0, 0)', hdr, hsearch) :
                      have_library(db, 'dbm_open("", 0, 0)', hdr, hsearch)) and
      have_func('dbm_clearerr((DBM *)0)', hdr, hsearch)
+    if /gdbm/ =~ db
+      have_var("gdbm_version", hdr, hsearch)
+      # gdbm_version is not declared by ndbm.h until gdbm 1.8.3.
+      # We can't include ndbm.h and gdbm.h because they both define datum type.
+      # ndbm.h includes gdbm.h and gdbm_version is declared since gdbm 1.9.
+      have_libvar(["gdbm_version", "char *"], hdr, hsearch)
+    end
     if hsearch
       $defs << hsearch
       @defs = hsearch