From 54bb4e2cce2ff3f415f2a133c9d49bd7f96e2498 Mon Sep 17 00:00:00 2001
From: Eric Blake
Date: Thu, 25 Feb 2010 14:56:34 -0700
Subject: [PATCH] Document how to safely override CFLAGS default.
* doc/autoconf.texi (C Compiler) : Document a way to
change the default CFLAGS.
(C++ Compiler) : Likewise, for CXXFLAGS.
Reported by Monty Taylor; wording suggested by Paolo Bonzini.
Signed-off-by: Eric Blake
---
ChangeLog | 6 ++++++
doc/autoconf.texi | 9 +++++++--
2 files changed, 13 insertions(+), 2 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index d27e870..f0be2df 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
2010-02-25 Eric Blake
+ Document how to safely override CFLAGS default.
+ * doc/autoconf.texi (C Compiler) : Document a way to
+ change the default CFLAGS.
+ (C++ Compiler) : Likewise, for CXXFLAGS.
+ Reported by Monty Taylor; wording suggested by Paolo Bonzini.
+
Recommend latest m4 release.
* README: Bump recommendation to m4 1.4.14 (minimum remains
1.4.6).
diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index a669d06..86d434c 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -7128,7 +7128,9 @@ C Compiler
@samp{yes}. If output variable @code{CFLAGS} was not already set, set
it to @option{-g -O2} for the @acronym{GNU} C compiler (@option{-O2} on systems
where @acronym{GCC} does not accept @option{-g}), or @option{-g} for
-other compilers.
+other compilers. If your package does not like this default, then it is
+acceptable to insert the line @samp{: ${CFLAGS=""}} after @code{AC_INIT}
+and before @code{AC_PROG_CC} to select an empty default instead.
Many Autoconf macros use a compiler, and thus call
@samp{AC_REQUIRE([AC_PROG_CC])} to ensure that the compiler has been
@@ -7529,7 +7531,10 @@ C++ Compiler
@samp{yes}. If output variable @code{CXXFLAGS} was not already set, set
it to @option{-g -O2} for the @acronym{GNU} C++ compiler (@option{-O2} on
systems where G++ does not accept @option{-g}), or @option{-g} for other
-compilers.
+compilers. If your package does not like this default, then it is
+acceptable to insert the line @samp{: ${CXXFLAGS=""}} after @code{AC_INIT}
+and before @code{AC_PROG_CXX} to select an empty default instead.
+
@end defmac
@defmac AC_PROG_CXXCPP
--
1.6.6.1