changes for detecting and building for clang/binutils elf

and minor fixes:
 . add ack/clean target to lib, 'unify' clean target
 . add includes as library dependency
 . mk: exclude warning options clang doesn't have in non-gcc
 . set -e in lib/*.sh build files
 . clang compile error circumvention (disable NOASSERTS for release builds)

lib/Makefile

@@ -18,23 +18,17 @@ SUBDIR+= libend
 build_ack:
 	sh ack_build.sh obj depend all install
 
+.if defined(MINIX_GENERATE_ELF)
+build_elf_base:
+	sh elf_build_base.sh obj depend all install
+.else
 build_gnu:
 	sh gnu_build.sh obj depend all install
+.endif
 
-build_clang:
-	sh clang_build.sh obj depend all install
-
-build_elf:
-	sh elf_build.sh obj depend all install
-
-clean_ack:
+clean_all:
 	sh ack_build.sh clean
-
-clean_gnu:
-	sh gnu_build.sh clean
-
-clean_elf:
-	sh elf_build.sh clean
-
-clean_clang:
 	sh clang_build.sh clean
+	sh gnu_build.sh clean
+	sh elf_build_base.sh clean
+	sh elf_build.sh clean

lib/ack_build.sh

@@ -1,5 +1,7 @@
 #!/bin/sh
 
+set -e
+
 export CC=cc
 export MAKEOBJDIR=obj-ack
 

lib/elf_build.sh

@@ -1,8 +1,15 @@
 #!/bin/sh
 
+# This file is obsolete and is only useful to 'clean' its objects.
+
 export CC=i386-pc-minix3-gcc
 export COMPILER_TYPE=gnu
 export MAKEOBJDIR=obj-elf
 export PATH=$PATH:/usr/gnu_cross/bin
 
+if [ "$@" != clean ]
+then	echo "$0: Unexpected arguments $@"
+	exit 1
+fi
+
 make $@

lib/elf_build_base.sh

@@ -0,0 +1,10 @@
+#!/bin/sh
+
+set -e
+
+export CC=clang
+export COMPILER_TYPE=gnu
+export MAKEOBJDIR=obj-elf-base
+export PATH=$PATH:/usr/pkg/bin
+
+make $@