GCC build option for elf libs and usr.bin

docs/UPDATING

@@ -3,8 +3,8 @@
 	make -C usr.bin/m4 install
 
 20110629:
-	You must install clang. It is now used to build some of
-	the userland utilities.
+	You must install clang. By default, it is used to build the
+	elf libraries and some userland utilities.
 
 20110628:
 	Since buildworld will also build the elf-libraries, you

lib/elf_build.sh

@@ -2,7 +2,7 @@
 
 set -e
 
-export CC=clang
+export CC=${CC:-clang}
 export COMPILER_TYPE=gnu
 export PATH=$PATH:/usr/pkg/bin
 

lib/libelf/Makefile

@@ -1,8 +1,8 @@
 # $Id$
 
-# Requires clang and NBSD_LIBC
+# Requires NBSD_LIBC and clang/gcc (we default to using clang)
 NBSD_LIBC:= yes
-CC:= clang
+CC:=${CC:C/^cc/clang/}
 COMPILER_TYPE:= gnu
 
 LIB=	elf

usr.bin/Makefile.inc

@@ -1,6 +1,6 @@
-# Require clang and NBSD_LIBC
+# Requires NBSD_LIBC and clang/gcc (we default to using clang)
 NBSD_LIBC:= yes
-CC:= clang
+CC:=${CC:C/^cc/clang/}
 COMPILER_TYPE:= gnu
 
 CPPFLAGS+= -D_NETBSD_SOURCE