build:wafsamba: Remove samba_utils.runonce

The decorator order matters in the following:
"""
@runonce
@conf
function()
"""

First, the @conf decorator binds the function to the configuration context
and then returns the same function. The @runonce decorator then takes
the output function and replaces it by another that performs caching. This new
function remains in the current script and is never bound to the configuration
context, so caching never occurs.

The declaration would have been correct if written like this:
"""
@conf
@runonce
function()
"""

Yet the decorator @run_once does not keep the function name (__name__), so the
annotation with @conf would fail. The straightforward approach is to remove
all the incorrect @runonce occurrences.

Besides that, the function Utils.run_once is already present in the Waf library,
and is sufficient for the current needs of the Samba code (it caches only the
first argument). Therefore samba_utils.runonce can be safely replaced by
Utils.run_once, which is also present in Waf 1.8.

Note: at runtime, only SETUP_BUILD_GROUPS seems to actually use caching.

Signed-off-by: Thomas Nagy <tnagy@waf.io>
Reviewed-by: Uri Simchoni uri@samba.org
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

6 files changed, 4 insertions, 30 deletions

diff --git a/buildtools/wafsamba/samba_autoconf.py b/buildtools/wafsamba/samba_autoconf.py
index 296f9fb843f..99ceb776b6f 100644
--- a/buildtools/wafsamba/samba_autoconf.py
+++ b/buildtools/wafsamba/samba_autoconf.py
@@ -4,7 +4,7 @@ import os, sys
 import Build, Options, preproc, Logs
 from Configure import conf
 from TaskGen import feature
-from samba_utils import TO_LIST, GET_TARGET_TYPE, SET_TARGET_TYPE, runonce, unique_list, mkdir_p
+from samba_utils import TO_LIST, GET_TARGET_TYPE, SET_TARGET_TYPE, unique_list, mkdir_p
 
 missing_headers = set()
 
@@ -13,7 +13,6 @@ missing_headers = set()
 # to waf a bit easier for those used to autoconf
 # m4 files
 
-@runonce
 @conf
 def DEFINE(conf, d, v, add_to_cflags=False, quote=False):
     '''define a config option'''
diff --git a/buildtools/wafsamba/samba_bundled.py b/buildtools/wafsamba/samba_bundled.py
index bfc7ecc8bc7..ea88807578f 100644
--- a/buildtools/wafsamba/samba_bundled.py
+++ b/buildtools/wafsamba/samba_bundled.py
@@ -3,7 +3,7 @@
 import sys
 import Build, Options, Logs
 from Configure import conf
-from samba_utils import TO_LIST, runonce
+from samba_utils import TO_LIST
 
 def PRIVATE_NAME(bld, name, private_extension, private_library):
     '''possibly rename a library to include a bundled extension'''
@@ -108,7 +108,6 @@ def LIB_MUST_BE_PRIVATE(conf, libname):
     return ('ALL' in conf.env.PRIVATE_LIBS or
             libname in conf.env.PRIVATE_LIBS)
 
-@runonce
 @conf
 def CHECK_BUNDLED_SYSTEM_PKG(conf, libname, minversion='0.0.0',
         onlyif=None, implied_deps=None, pkg=None):
@@ -122,7 +121,6 @@ def CHECK_BUNDLED_SYSTEM_PKG(conf, libname, minversion='0.0.0',
                                      implied_deps=implied_deps,
                                      pkg=pkg)
 
-@runonce
 @conf
 def CHECK_BUNDLED_SYSTEM(conf, libname, minversion='0.0.0',
                          checkfunctions=None, headers=None, checkcode=None,
@@ -219,7 +217,6 @@ def CHECK_BUNDLED_SYSTEM(conf, libname, minversion='0.0.0',
 def tuplize_version(version):
     return tuple([int(x) for x in version.split(".")])
 
-@runonce
 @conf
 def CHECK_BUNDLED_SYSTEM_PYTHON(conf, libname, modulename, minversion='0.0.0'):
     '''check if a python module is available on the system and
diff --git a/buildtools/wafsamba/samba_perl.py b/buildtools/wafsamba/samba_perl.py
index c07387a372e..f2f176d813b 100644
--- a/buildtools/wafsamba/samba_perl.py
+++ b/buildtools/wafsamba/samba_perl.py
@@ -5,12 +5,6 @@ done = {}
 
 @conf
 def SAMBA_CHECK_PERL(conf, mandatory=True, version=(5,0,0)):
-    #
-    # TODO: use the @runonce mechanism for this.
-    # The problem is that @runonce currently does
-    # not seem to work together with @conf...
-    # So @runonce (and/or) @conf needs fixing.
-    #
     if "done" in done:
         return
     done["done"] = True
diff --git a/buildtools/wafsamba/samba_utils.py b/buildtools/wafsamba/samba_utils.py
index 5776be89717..fbe89f06f02 100644
--- a/buildtools/wafsamba/samba_utils.py
+++ b/buildtools/wafsamba/samba_utils.py
@@ -35,22 +35,6 @@ def GET_TARGET_TYPE(ctx, target):
     return cache[target]
 
 
-######################################################
-# this is used as a decorator to make functions only
-# run once. Based on the idea from
-# http://stackoverflow.com/questions/815110/is-there-a-decorator-to-simply-cache-function-return-values
-def runonce(function):
-    runonce_ret = {}
-    def runonce_wrapper(*args):
-        if args in runonce_ret:
-            return runonce_ret[args]
-        else:
-            ret = function(*args)
-            runonce_ret[args] = ret
-            return ret
-    return runonce_wrapper
-
-
 def ADD_LD_LIBRARY_PATH(path):
     '''add something to LD_LIBRARY_PATH'''
     if 'LD_LIBRARY_PATH' in os.environ:
diff --git a/buildtools/wafsamba/wafsamba.py b/buildtools/wafsamba/wafsamba.py
index 318dabf44e1..a8e122c9575 100644
--- a/buildtools/wafsamba/wafsamba.py
+++ b/buildtools/wafsamba/wafsamba.py
@@ -674,7 +674,7 @@ Build.BuildContext.SAMBA_GENERATOR = SAMBA_GENERATOR
 
 
 
-@runonce
+@Utils.run_once
 def SETUP_BUILD_GROUPS(bld):
     '''setup build groups used to ensure that the different build
     phases happen consecutively'''
diff --git a/buildtools/wafsamba/wscript b/buildtools/wafsamba/wscript
index 69c556c888d..6df3c57fa35 100755
--- a/buildtools/wafsamba/wscript
+++ b/buildtools/wafsamba/wscript
@@ -203,7 +203,7 @@ def set_options(opt):
                     metavar="PYTHON", dest='EXTRA_PYTHON', default=None)
 
 
-@wafsamba.runonce
+@Utils.run_once
 def configure(conf):
     conf.env.hlist = []
     conf.env.srcdir = conf.srcdir