build: introduce SAMBA_CHECK_PYTHON_HEADERS

This function is a wrapper around waf's check_python_header.
It avoids searching more than once for the headers bringing a small
speed improvement and a better lisibility of the logs.

But it's mainly to avoid a nasty bug when python libraries are in path
pointed by python_LIBPL (ie. /usr/local/lib/python2.6/config/) instead
of python_LIBDIR (ie. /usr/local/lib).

On the first call waf will correctly find that in order to link with
python libs it needs to add -L$python_LIBPL.

But on the next calls of check_python_headers, waf will use both the
current library path value (ie. -L/usr/local/lib/python2.6/config) and
-L$python_LIBDIR (ie. /usr/local/lib/) which will make him beleive that
python libraries are in $python_LIBDIR which at the end will make the
final link test fails in check_python_headers as it will not use the
good directory.

So by avoiding calling check_python_headers more than once we avoid
making waf fooling itself.

5 files changed, 13 insertions, 4 deletions

diff --git a/buildtools/wafsamba/samba_python.py b/buildtools/wafsamba/samba_python.py
index ad09981462..a663b1910d 100644
--- a/buildtools/wafsamba/samba_python.py
+++ b/buildtools/wafsamba/samba_python.py
@@ -4,6 +4,15 @@ import Build
 from samba_utils import *
 from samba_autoconf import *
 
+from Configure import conf
+@conf
+def SAMBA_CHECK_PYTHON_HEADERS(conf, mandatory=True):
+    if conf.env["python_headers_checked"] == []:
+        conf.check_python_headers(mandatory)
+        conf.env["python_headers_checked"] = "yes"
+    else:
+        conf.msg("python headers", "using cache")
+
 
 def SAMBA_PYTHON(bld, name,
                  source='',
diff --git a/lib/talloc/wscript b/lib/talloc/wscript
index 6316abafd8..49eac6e6e6 100644
--- a/lib/talloc/wscript
+++ b/lib/talloc/wscript
@@ -59,7 +59,7 @@ def configure(conf):
         # also disable if we don't have the python libs installed
         conf.check_tool('python')
         conf.check_python_version((2,4,2))
-        conf.check_python_headers(mandatory=False)
+        conf.SAMBA_CHECK_PYTHON_HEADERS(mandatory=False)
         if not conf.env.HAVE_PYTHON_H:
             Logs.warn('Disabling pytalloc-util as python devel libs not found')
             conf.env.disable_python = True
diff --git a/lib/tdb/wscript b/lib/tdb/wscript
index fadd24f60f..f00d119c9b 100644
--- a/lib/tdb/wscript
+++ b/lib/tdb/wscript
@@ -47,7 +47,7 @@ def configure(conf):
         # also disable if we don't have the python libs installed
         conf.check_tool('python')
         conf.check_python_version((2,4,2))
-        conf.check_python_headers(mandatory=False)
+        conf.SAMBA_CHECK_PYTHON_HEADERS(mandatory=False)
         if not conf.env.HAVE_PYTHON_H:
             Logs.warn('Disabling pytdb as python devel libs not found')
             conf.env.disable_python = True
diff --git a/lib/tevent/wscript b/lib/tevent/wscript
index 14c4c60319..58ef87e1ab 100644
--- a/lib/tevent/wscript
+++ b/lib/tevent/wscript
@@ -48,7 +48,7 @@ def configure(conf):
         # also disable if we don't have the python libs installed
         conf.check_tool('python')
         conf.check_python_version((2,4,2))
-        conf.check_python_headers(mandatory=False)
+        conf.SAMBA_CHECK_PYTHON_HEADERS(mandatory=False)
         if not conf.env.HAVE_PYTHON_H:
             Logs.warn('Disabling pytevent as python devel libs not found')
             conf.env.disable_python = True
diff --git a/source4/wscript b/source4/wscript
index dabca7f69c..fb0491972b 100644
--- a/source4/wscript
+++ b/source4/wscript
@@ -74,7 +74,7 @@ def configure(conf):
     # enable tool to build python extensions
     conf.check_tool('python')
     conf.check_python_version((2,4,2))
-    conf.check_python_headers(mandatory=True)
+    conf.SAMBA_CHECK_PYTHON_HEADERS(mandatory=True)
 
     if sys.platform == 'darwin' and not conf.env['HAVE_ENVIRON_DECL']:
         # Mac OSX needs to have this and it's also needed that the python is compiled with this