Implement 'ct-ng source'.

Provides a simpler alternative to editing config to enable
CT_ONLY_DOWNLOAD, doing ct-ng build and then restoring .config.

Signed-off-by: Alexey Neyman <stilor@att.net>

ct-ng.in

@@ -104,6 +104,7 @@ help-tail::
 	@echo  'See "man 1 $(notdir $(CT_NG))" for some help as well'
 
 help-build::
+	@echo  '  source             - Download sources for currently configured toolchain'
 	@echo  '  build[.#]          - Build the currently configured toolchain'
 
 help-clean::
@@ -143,6 +144,9 @@ show-tuple: .config.2
 	$(SILENT)$(bash) $(CT_LIB_DIR)/scripts/showTuple.sh
 
 # Actual build
+source: .config.2
+	$(SILENT)CT_SOURCE=y $(CT_LIB_DIR)/scripts/crosstool-NG.sh
+
 build: .config.2
 	$(SILENT)$(CT_LIB_DIR)/scripts/crosstool-NG.sh
 

scripts/crosstool-NG.sh.in

@@ -524,6 +524,9 @@ if [ -z "${CT_RESTART}" ]; then
     [ ${CT_PARALLEL_JOBS} -gt 0 ] && JOBSFLAGS="${JOBSFLAGS} -j${CT_PARALLEL_JOBS}"
     JOBSFLAGS="${JOBSFLAGS} -l${CT_LOAD}"
 
+    # Override 'download only' option
+    [ -n "${CT_SOURCE}" ] && CT_ONLY_DOWNLOAD=y
+
     # Now that we've set up $PATH and $CT_CFLAGS_FOR_HOST, sanity test that gcc
     # is runnable so that the user can troubleshoot problems if not.
     CT_DoStep DEBUG "Checking that we can run gcc -v"