- Issue #4587: Add configure option --with-dbmliborder=db1:db2:... to specify

the order that backends for the dbm extension are checked.

Misc/NEWS

@@ -814,6 +814,9 @@ Tools/Demos
 Build
 -----
 
+- Issue #4587: Add configure option --with-dbmliborder=db1:db2:... to specify
+  the order that backends for the dbm extension are checked. 
+
 - Link the shared python library with $(MODLIBS).
 
 - Issue #5134: Silence compiler warnings when compiling sqlite with VC++.

README

@@ -1068,6 +1068,9 @@ Modules/getpath.o.
 --with-system-ffi:  Build the _ctypes extension module using an ffi
         library installed on the system.
 
+--with-dbmliborder=db1:db2:...:  Specify the order that backends for the
+	dbm extension are checked. Valid value is a colon separated string
+	with the backend names `ndbm', `gdbm' and `bdb'.
 
 Building for multiple architectures (using the VPATH feature)
 -------------------------------------------------------------

configure.in

@@ -1918,6 +1918,26 @@ AC_ARG_WITH(system_ffi,
 
 AC_MSG_RESULT($with_system_ffi)
 
+# Check for --with-dbmliborder
+AC_MSG_CHECKING(for --with-dbmliborder)
+AC_ARG_WITH(dbmliborder,
+            AC_HELP_STRING(--with-dbmliborder=db1:db2:..., order to check db backends for dbm),
+[
+if test x$with_dbmliborder = xyes
+then
+AC_MSG_ERROR([proper usage is --with-dbmliborder=db1:db2:...])
+else
+  for db in `echo $with_dbmliborder | sed 's/:/ /g'`; do
+    if test x$db != xndbm && test x$db != xgdbm && test x$db != xbdb
+    then
+      AC_MSG_ERROR([proper usage is --with-dbmliborder=db1:db2:...])
+    fi
+  done
+  AC_MSG_RESULT($with_dbmliborder)
+fi],
+[AC_MSG_ERROR([proper usage is --with-dbmliborder=db1:db2:...])
+])
+
 # Determine if signalmodule should be used.
 AC_SUBST(USE_SIGNAL_MODULE)
 AC_SUBST(SIGNAL_OBJS)

setup.py

@@ -1000,39 +1000,68 @@ class PyBuildExt(build_ext):
 
         # The standard Unix dbm module:
         if platform not in ['cygwin']:
+            config_args = sysconfig.get_config_var("CONFIG_ARGS")
+            dbm_args = [arg.split('=')[-1] for arg in args.split()
+                        if arg.startswith('--with-dbmliborder=')]
+            if dbm_args:
+                dbm_order = "ndbm:gdbm:bdb".split(":")
+            else:
+                dbm_order = dbm_args.split(":")
+            dbmext = None
+            for cand in dbm_order:
+                if cand == "ndbm":
                     if find_file("ndbm.h", inc_dirs, []) is not None:
                         # Some systems have -lndbm, others don't
                         if self.compiler.find_library_file(lib_dirs, 'ndbm'):
                             ndbm_libs = ['ndbm']
                         else:
                             ndbm_libs = []
-                exts.append( Extension('dbm', ['dbmmodule.c'],
+                        print "building dbm using ndbm"
-                                       define_macros=[('HAVE_NDBM_H',None)],
+                        dbmext = Extension('dbm', ['dbmmodule.c'],
-                                       libraries = ndbm_libs ) )
+                                           define_macros=[
-            elif self.compiler.find_library_file(lib_dirs, 'gdbm'):
+                                               ('HAVE_NDBM_H',None),
+                                               ],
+                                           libraries=ndbm_libs)
+                        break
+
+                elif cand == "gdbm":
+                    if self.compiler.find_library_file(lib_dirs, 'gdbm'):
                         gdbm_libs = ['gdbm']
                         if self.compiler.find_library_file(lib_dirs, 'gdbm_compat'):
                             gdbm_libs.append('gdbm_compat')
                         if find_file("gdbm/ndbm.h", inc_dirs, []) is not None:
-                    exts.append( Extension(
+                            print "building dbm using gdbm"
+                            dbmext = Extension(
                                 'dbm', ['dbmmodule.c'],
-                        define_macros=[('HAVE_GDBM_NDBM_H',None)],
+                                define_macros=[
-                        libraries = gdbm_libs ) )
+                                    ('HAVE_GDBM_NDBM_H', None),
-                elif find_file("gdbm-ndbm.h", inc_dirs, []) is not None:
+                                    ],
-                    exts.append( Extension(
+                                libraries = gdbm_libs)
+                            break
+                        if find_file("gdbm-ndbm.h", inc_dirs, []) is not None:
+                            print "building dbm using gdbm"
+                            dbmext = Extension(
                                 'dbm', ['dbmmodule.c'],
-                        define_macros=[('HAVE_GDBM_DASH_NDBM_H',None)],
+                                define_macros=[
-                        libraries = gdbm_libs ) )
+                                    ('HAVE_GDBM_DASH_NDBM_H', None),
-                else:
+                                    ],
-                    missing.append('dbm')
+                                libraries = gdbm_libs)
-            elif db_incs is not None:
+                            break
-                exts.append( Extension('dbm', ['dbmmodule.c'],
+                elif cand == "bdb":
+                    if db_incs is not None:
+                        print "building dbm using bdb"
+                        dbmext = Extension('dbm', ['dbmmodule.c'],
                                            library_dirs=dblib_dir,
                                            runtime_library_dirs=dblib_dir,
                                            include_dirs=db_incs,
-                                       define_macros=[('HAVE_BERKDB_H',None),
+                                           define_macros=[
-                                                      ('DB_DBM_HSEARCH',None)],
+                                               ('HAVE_BERKDB_H', None),
-                                       libraries=dblibs))
+                                               ('DB_DBM_HSEARCH', None),
+                                               ],
+                                           libraries=dblibs)
+                        break
+            if dbmext is not None:
+                exts.append(dbmext)
             else:
                 missing.append('dbm')