[PATCH] Allow BUILD_CFLAGS and TARGET_CFLAGS to be specified at configure time

[Simon Horman]

On Tue, Jul 15, 2008 at 10:08:22PM +1000, Jeremy Kerr wrote:
> Currently, we're unconditionally setting the build and target cflags in
> the configure script, which means that they can't be easily
> overwritten.
> 
> This change conditionally sets these variables if they're not specified
> during configure, allowing something like:
> 
> BUILD_CFLAGS=-Werror ./configure
> 
> Signed-off-by: Jeremy Kerr <jk at ozlabs.org>
> 
> ---
>  configure.ac |    9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/configure.ac b/configure.ac
> index 5f1c15a..fa5330a 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -56,8 +56,13 @@ if test "${host_alias}" ; then
>  	OBJDIR="$OBJDIR-${host_alias}"
>  fi
>  
> -BUILD_CFLAGS='-O2 -Wall'
> -TARGET_CFLAGS='-O2 -Wall'
> +if test "x$BUILD_CFLAGS" = "x" ; then
> +	BUILD_CFLAGS='-O2 -Wall'
> +fi
> +
> +if test "x$TARGET_CFLAGS" = "x" ; then
> +	TARGET_CFLAGS='-O2 -Wall'
> +fi
>  
>  AC_ARG_WITH([objdir], AC_HELP_STRING([--with-objdir=<dir>],[select directory for object files]),
>  	[ OBJDIR="$withval" ], [ OBJDIR="$OBJDIR" ])

Can we get rid of TARGET_CFLAGS? It doesn't seem to be used anywhere.

Also I think you need the following util/Makefile snippet as Bernhards
patch is already in the tree (I was working on a similar patch myself :-)

diff --git a/util/Makefile b/util/Makefile
index a1a78ac..0ea59d4 100644
--- a/util/Makefile
+++ b/util/Makefile
@@ -5,8 +5,8 @@ $(BIN_TO_HEX): $(srcdir)/util/bin-to-hex.c
 	$(LINK.o) $(CFLAGS) -o $@ $^
 
 $(BIN_TO_HEX): CC=$(BUILD_CC)
-$(BIN_TO_HEX): CFLAGS+=$(BUILD_CFLAGS)
-$(BIN_TO_HEX): LDFLAGS=
+$(BIN_TO_HEX): CFLAGS=$(BUILD_CFLAGS)
+$(BIN_TO_HEX): LDFLAGS=$(BUILD_LDFLAGS)
 
 dist += util/Makefile util/bin-to-hex.c
 clean += util/bin-to-hex.o $(BIN_TO_HEX)