bug#9755: 24.0.90; trying to configure with GCC 4.6.1 on intel Mac OS X 10.6.8

bug#9755: 24.0.90; trying to configure with GCC 4.6.1 on intel Mac OS X 10.6.8

[Peter Dyballa]

Hello!

The configure scripts adds "-no-cpp-precomp" to CPPFLAGS although GCC 4.6.1 does not support this Apple addition:

	configure:5751: checking how to run the C preprocessor
	configure:5821: result: gcc-4 -E -no-cpp-precomp -I/opt/local/include -L/opt/local/lib
	configure:5841: gcc-4 -E -no-cpp-precomp -I/opt/local/include -L/opt/local/lib  conftest.c
	gcc-4: error: unrecognized option '-no-cpp-precomp'

A configure option like "-no-apple-stuff" would be nice – or removing the -no-cpp-precomp section. Everyone who thinks this option is needed can add it to the CPPFLAGS.

--
Greetings

  Pete

Life is the only flaw in an otherwise perfect nonexistence
				– Schopenhauer

bug#9755: 24.0.90; trying to configure with GCC 4.6.1 on intel Mac OS X 10.6.8

[Glenn Morris]

close 9755 24.2
stop

Peter Dyballa wrote:

> The configure scripts adds "-no-cpp-precomp" to CPPFLAGS although GCC
> 4.6.1 does not support this Apple addition:


The history here is that -no-cpp-precomp was needed for some reason with
some older versions of Apple's version of gcc. The Emacs configure
script unconditionally set CPP to 'cc -E -no-cpp-precomp' on all darwin
builds for this reason, without bothering to test which compiler was
being used.

This is not too much of an issue in gcc prior to 4.6, because gcc
-no-foo returns status 0, even when -no-foo is an unknown option
(it warns but continues). In gcc 4.6 and later, it returns an error.

Hence Emacs 24.1 will not configure with gcc 4.6 and later on OS X.

The Hydra darwin builds of Emacs seem to have been failing for this
reason for some time.

I just installed a change to the trunk to hopefully fix this (r108250).

It might be better to just remove this -no-cpp-precomp altogether.
AFAICS, it is only needed for Apple gcc earlier than 3.3 (not sure).
That is pretty old.


This might be something to backport to 24.1, I'm not sure.
The patch might need altering if bug#11485 is fixed in 24.1.

Also even after making this change, the build fails during dumping.
http://debbugs.gnu.org/9927
http://hydra.nixos.org/build/2630203

bug#9755: 24.0.90 trying to configure with GCC 4.6.1 on intel Mac OS X 10.6.8

[Paul Eggert]

Given that CPP doesn't need to be set any more
(see <http://debbugs.gnu.org/cgi/bugreport.cgi?bug=11485#9>),
I propose this patch to emacs-24's configure.in:

=== modified file 'configure.in'
--- configure.in	2012-05-05 10:18:38 +0000
+++ configure.in	2012-05-16 09:13:51 +0000
@@ -492,8 +492,6 @@ case "${canonical}" in
       * )            unported=yes ;;
     esac
     opsys=darwin
-    # Define CPP as follows to make autoconf work correctly.
-    CPP="${CC-cc} -E -no-cpp-precomp"
     # Use fink packages if available.
     if test -d /sw/include && test -d /sw/lib; then
       GCC_TEST_OPTIONS="-I/sw/include -L/sw/lib"
@@ -582,7 +580,6 @@ case "${canonical}" in
     case "${canonical}" in
       *-cygwin )                opsys=cygwin ;;
       *-darwin* )               opsys=darwin
-                                CPP="${CC-cc} -E -no-cpp-precomp"
  				;;
       *-sysv4.2uw* )	  	opsys=unixware; NON_GNU_CPP=/lib/cpp ;;
       *-sysv5uw* )	  	opsys=unixware; NON_GNU_CPP=/lib/cpp ;;