From 25a2779b00f20c67c57fbe41efad551a6c1e9d4f Mon Sep 17 00:00:00 2001
From: dtucker <dtucker>
Date: Mon, 18 Sep 2006 13:17:40 +0000
Subject: [PATCH]  - (dtucker) [configure.ac] On AIX, check to see if the
 compiler will allow    macro redefinitions, and if not, remove
 "-qlanglvl=ansi" from the flags.    Allows build out of the box with older
 VAC and XLC compilers.  Found by    David Bronder and Bernhard Simon.

---
 ChangeLog    |  6 ++++++
 configure.ac | 21 +++++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index 2973498f..c1de453a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+20060918
+ - (dtucker) [configure.ac] On AIX, check to see if the compiler will allow
+   macro redefinitions, and if not, remove "-qlanglvl=ansi" from the flags.
+   Allows build out of the box with older VAC and XLC compilers.  Found by
+   David Bronder and Bernhard Simon.
+
 20060916
  - OpenBSD CVS Sync
    - djm@cvs.openbsd.org 2006/09/16 19:53:37
diff --git a/configure.ac b/configure.ac
index 365eac46..af92560e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -134,6 +134,27 @@ SPC_MSG="no"
 # Check for some target-specific stuff
 case "$host" in
 *-*-aix*)
+	# Some versions of VAC won't allow macro redefinitions at
+	# -qlanglevel=ansi, and autoconf 2.60 sometimes insists on using that
+	# particularly with older versions of vac or xlc.
+	# It also throws errors about null macro argments, but these are
+	# not fatal.
+	AC_MSG_CHECKING(if compiler allows macro redefinitions)
+	AC_COMPILE_IFELSE(
+	    [AC_LANG_SOURCE([[
+#define testmacro foo
+#define testmacro bar
+int main(void) { exit(0); }
+	    ]])],
+	    [ AC_MSG_RESULT(yes) ],
+	    [ AC_MSG_RESULT(no)
+	      CC="`echo $CC | sed 's/-qlanglvl\=ansi//g'`"
+	      LD="`echo $LD | sed 's/-qlanglvl\=ansi//g'`"
+	      CFLAGS="`echo $CFLAGS | sed 's/-qlanglvl\=ansi//g'`"
+	      CPPFLAGS="`echo $CPPFLAGS | sed 's/-qlanglvl\=ansi//g'`"
+	    ]
+	)
+
 	AC_MSG_CHECKING([how to specify blibpath for linker ($LD)])
 	if (test -z "$blibpath"); then
 		blibpath="/usr/lib:/lib"
-- 
2.45.2