[Buildroot] [PATCH v4] ccache: expose control interface via 'make ccache-options'

[Tzu-Jung Lee]

usage:
	# set cache limit size
	make CCACHE_OPTIONS="--max-size=5G" ccache-options

	# zero statistics counters
	make CCACHE_OPTIONS="--zero-stats" ccache-options

Signed-off-by: Tzu-Jung Lee <tjlee at ambarella.com>
---
Include the useful warning message suggested by Thomas.

We might need a separate patch to obsolete the ccache-stats later.

 docs/manual/ccache-support.txt | 11 +++++++++++
 package/ccache/ccache.mk       | 11 +++++++++++
 2 files changed, 22 insertions(+)

diff --git a/docs/manual/ccache-support.txt b/docs/manual/ccache-support.txt
index 4969180..fe06a01 100644
--- a/docs/manual/ccache-support.txt
+++ b/docs/manual/ccache-support.txt
@@ -23,3 +23,14 @@ remove this directory.
 
 You can get statistics on the cache (its size, number of hits,
 misses, etc.) by running +make ccache-stats+.
+
+The make target +ccache-options+ and the +CCACHE_OPTIONS+ variable
+provide more generic access to the ccache. For example
+
+-----------------
+# set cache limit size
+make CCACHE_OPTIONS="--max-size=5G" ccache-options
+
+# zero statistics counters
+make CCACHE_OPTIONS="--zero-stats" ccache-options
+-----------------
diff --git a/package/ccache/ccache.mk b/package/ccache/ccache.mk
index c5e9385..7b6155d 100644
--- a/package/ccache/ccache.mk
+++ b/package/ccache/ccache.mk
@@ -45,3 +45,14 @@ ifeq ($(BR2_CCACHE),y)
 ccache-stats: host-ccache
 	$(Q)$(CCACHE) -s
 endif
+
+ifeq ($(BR2_CCACHE),y)
+ccache-options: host-ccache
+ifeq ($(CCACHE_OPTIONS),)
+	$(Q)echo "Usage: make ccache-options CCACHE_OPTIONS=\"opts\""
+	$(Q)echo "where 'opts' corresponds to one or more valid ccache options" \
+	"(see ccache help text below)"
+	$(Q)echo
+endif
+	$(Q)$(CCACHE) $(CCACHE_OPTIONS)
+endif
-- 
1.8.3.2