Re: [Plplot-devel] problem with --disable-cxx

[Maurice L. <mj...@ga...>]

Maurice LeBrun writes:
 > Alan W. Irwin writes:
 >  > On Thu, 26 Dec 2002, Maurice LeBrun wrote:
 >  > 
 >  > > ged$ ./configure --prefix=$HOME/tools --enable-dyndrivers --disable-cxx
 >  > > ...
 >  > > configure: error: conditional "am__fastdepCXX" was never defined.
 >  > > Usually this means the macro was only invoked conditionally.

I think I've tracked this down to some lunacy being done inside the
AC_PROG_CXX macro, as you might expect.  Using AC_* macros inside of
conditionals has bitten me on the butt before.. doesn't anyone else use
alternate paths of logic in configure.ac (or .in) files?  Jeez.

I moved AC_PROG_CXX outside of the test, i.e.

if test "$enable_cxx" = yes; then
  ...
fi
AC_PROG_CXX

and now it works fine.  I think the reason it wasn't seen by Alan is that it's
from a relatively new change and I'm working with the latest version.

I don't suppose it really matters if we check for the presence of a C++
compiler despite $enable_cxx being set to "no", except for the possibility of
it being confusing to the user.  But now there's so much configure output that
you have to look closely to even see it anyway :/.  So I'm going to leave it
as-is.  Those wanting to reproduce the bug should install the packages I'm
using and move AC_PROG_CXX back up one line, then configure with cxx disabled.

Grumble..

-- 
Maurice LeBrun    mj...@ga...
Research Organization for Information Science and Technology of Japan (RIST)