waf vs enrionment CPPFLAGS and LDFLAGS

[Jeremy Allison]

On Tue, Oct 28, 2014 at 12:22:50PM +0100, Ralph Böhme wrote:
> On Tue, Oct 28, 2014 at 12:05:00PM +0100, Ralph Böhme wrote:
> > Hi Jeremy,
> > 
> > On Mon, Oct 27, 2014 at 05:04:26PM -0700, Jeremy Allison wrote:
> > > On Mon, Oct 27, 2014 at 06:25:28PM +0100, Ralph Böhme wrote:
> > > > Hi all,
> > > > 
> > > > I think I've come across a behaviour in waf which I'd consider a bug [1]:
> > > > 
> > > > when building the C compiler invocation for compiling or linking, waf
> > > > places the environment varialbles CPPFLAGS and LDFLAGS *before* all
> > > > internal flags computed at the configuration stage.
> > > > 
> > > > The templates come from buildtools/wafadmin/Tools/cc.py:
> > > > 
> > > > cc_str = '${CC} ${CCFLAGS} ${CPPFLAGS} ${_CCINCFLAGS} ${_CCDEFFLAGS} ${CC_SRC_F}${SRC} ${CC_TGT_F}${TGT}'
> > > > link_str = '${LINK_CC} ${CCLNK_SRC_F}${SRC} ${CCLNK_TGT_F}${TGT[0].abspath(env)} ${LINKFLAGS}'
> > > > 
> > > > As a result, a Samba build will erroneously pick up headers or
> > > > libraries from the paths specified in the environment variables, no
> > > > matter what the waf build script intention is.
> > > > 
> > > > This manifested in a broken build of Samba 4.1.12 with Macport on OS
> > > > X. Macports passed CPPFLAGS=-I/some/path to waf configure where in
> > > > /some/path happened to exist GSSAPI headers. The internal heimdal
> > > > build then picked up those headers instead of the internal copies,
> > > > because -I/some/path was put infront of the internal include.
> > > > 
> > > > Note that this is NOT specifically related to our GSSAPI/Heimdal
> > > > build, it's a general waf bug. The immediate fix is:
> > > > 
> > > > <http://git.samba.org/?p=slow/samba.git;a=commitdiff;h=2429a9f65c0da893c5e843fa52568a913b388bfc>
> > > > 
> > > > Fwiw, this bug is still present in upstream waf.
> > > 
> > > Ralph, have you submitted this upstream ?
> > 
> > I tried, but I failed. :/ Thomas silently dropped my posts to
> > waf-users twice. After pinging him by mail all I could get out of him
> > was a request to file a bugreport. I'll do that now.
> 
> <https://code.google.com/p/waf/issues/detail?id=1505>

Great - thanks. Can you re-submit your waf fix for
the Samba tree and I'll review asap.