xcompile: fail earlier on missing host tools

No need to test all the cross compiler things if
there's no host compiler or iasl.
Also test that the alternatives work, instead of
assuming iasl or cc are in the path.

Change-Id: I1d2293873f4bf1bb525d794851ec20adddb05ac6
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/5742
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

util/xcompile/xcompile

@@ -20,6 +20,7 @@
 #
 
 TMPFILE=""
+XGCCPATH=${1:-"`pwd`/util/crossgcc/xgcc/bin/"}
 
 die() {
 	echo "ERROR: $*" >&2
@@ -36,6 +37,32 @@ program_exists() {
 	type "$1" >/dev/null 2>&1
 }
 
+
+if [ "$(${XGCCPATH}/iasl 2>/dev/null | grep -c ACPI)" -gt 0 ]; then
+	IASL=${XGCCPATH}iasl
+elif [ "$(iasl 2>/dev/null | grep -c ACPI)" -gt 0 ]; then
+	IASL=iasl
+else
+	echo "no iasl found"
+	exit 1
+fi
+
+if program_exists gcc; then
+	HOSTCC=gcc
+elif program_exists cc; then
+	HOSTCC=cc
+else
+	echo "no host compiler found"
+	exit 1
+fi
+
+cat <<EOF
+# platform agnostic and host tools
+IASL:=${IASL}
+HOSTCC:=${HOSTCC}
+
+EOF
+
 testcc() {
 	local tmp_c="$TMPFILE.c"
 	local tmp_o="$TMPFILE.o"
@@ -163,8 +190,6 @@ arch_config_x86() {
 	TWIDTH="32"
 }
 
-XGCCPATH=${1:-"`pwd`/util/crossgcc/xgcc/bin/"}
-
 # This loops over all supported architectures.
 for architecture in $SUPPORTED_ARCHITECTURE; do
 	GCCPREFIX="invalid"
@@ -207,21 +232,3 @@ for architecture in $SUPPORTED_ARCHITECTURE; do
 	report_arch_toolchain
 done
 
-if [ "$(${XGCCPATH}/iasl 2>/dev/null | grep -c ACPI)" -gt 0 ]; then
-	IASL=${XGCCPATH}iasl
-else
-	IASL=iasl
-fi
-
-if program_exists gcc; then
-	HOSTCC=gcc
-else
-	HOSTCC=cc
-fi
-
-cat <<EOF
-IASL:=${IASL}
-
-# native toolchain
-HOSTCC:=${HOSTCC}
-EOF